US3550847A - Pneumatically operated logic system or the like - Google Patents

Description

United States Patent [72] lnventor Douglas R. Scott Elkhart, Ind. [21] Appl. No. 821,928 [22] Filed May 5,1969 [45] Patented Dec. 29, 1970 [73] Assignee Robertshaw Controls Company Richmond, Va. a corporation of Delaware Continuation-impart of application Ser. No. 717,586, Apr. 1, 1968, now Patent No. 3,522,661. This application May 5, 1969, Ser. No. 821,928

[54] PNEUMATICALLY OPERATED LOGIC SYSTEM OR THELIKE 7 Claims, 27 Drawing Figs.

[52] 11.8.C1 235/201, 137/625.66; 251/61 [51] Int. Cl. G06d 3/00 [50] Field ofSearch 235/200, 201:251,61; 137/84 [56] References Cited UNITED STATES PATENTS 2,991,805 7/1961Page 235/201 3,155,825 11/1964 Boothe... 235/201 3,303,999 2/1967 Mamy 235/201 Primary Examiner-Richard B. Wilkinson Assistant Examiner-Lawrence R. Franklin Attorneys-Auzville Jackson, Jr., Robert L. Marben and Candor, Candor & Tassonc ABSTRACT: A logic unit that can be pressure operated or vacuum operated in a system to provide logic functions such as an AND function, an OR function, a NOT function, a DELAY function, a PULSE SHAPER function, a MEMORY function, an OSCILLATOR function, a F LlP-F LOP function, and the like, the logic unit comprising an integral threediaphragm member cooperating with a housing means to define four stacked chambers respectively interconnected to four ports of the housing means with a fifth port also being fluidly interconnected to one of the outboard chambers. The diaphragm member has passage means passing therethrough always fluidly interconnecting the two outboard chambers together with the ports for the two outboard chambers defining valve seats adapted to be respectively opened and closed by the diaphragm member. Urging means tends to move the diaphragm member in one direction to close the valve seat of the outboard chamber having the fifth port interconnected thereto.

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SHEET 6 BF 7' I 4 I v. I I 49, J P/IOQA 48 H 48 '4 84 DOU G IXE KQS OTT HIS ATTORNEYS PATENTED [1:029mm sum 7CF 7 INVENTOR. DOUGLAS R. SCOTT w, awzzam HIS ATTORNEYS PNEUMATICALLY OPERATED LOGIC SYSTEM OR THE LIKE This application is a continuation-in-part patent application of its copending parent patent application, Ser. No. 717,586, filed Apr. 1, I968, now U.S. Pat. No. 3,522,661 and is assigned to the same assignee to whom the parent application is assigned. 1

This invention relates to pneumatically operated logic systems and the like.

A logic unit is provided by this invention which can be pressure operated or vacuum operated and can be utilized in various pneumatically operated systems to provide different logic functions without any change in the structure of the logic unit.

Such a pneumatically operated unit when utilized as a valving means is disclosed and claimed in the copending U.S. Pat. application, Ser. No. 772,788, filed Nov. 1, 1968, and assigned to the same assignee to whom this application is assigned. 4

Parent copending U.S. Pat. application, Ser. No. 717,586, discloses and claims a pneumatically operated cloghes dryer control system wherein the logic unit can be utillzed as a vacuum operated AND logic unit, a vacuum operated NOT unit and a vacuum operated MEMORY unit.

This application further discloses such a pneumatically operated logic unit having universal application for other types of logic functions such as pressure operated or vacuum operated AND functions, OR functions, NOT functions, DELAY functions, PULSE SI-IAPER functions, MEMORY functions, OSCILLATOR functions and FLIP-FLOP functions.

For example, the logic unit of this invention comprises a housing means carrying a diaphragm member that has three integral diaphragm portions in axially stacked spaced relation and cooperating with the housing means to define four axially stacked chambers separated from each other, the diaphragm member having passage means therein always fluidly interconnecting the two outboard chambers together. The housing means has only five ports therein of which four ports thereof respectively lead to the four chambers with the ports for the two outboard chambers respectively defining valve seats respectively leading to the two outboard chambers and being adapted to be opened and closed respectively by the diaphragm member, the fifth port leading to one of the outboard chambers to always be in fluid communication therewith regardless of the position of the diaphragm member. The housing means has an urging means always tending to move the diaphragm member in one direction to close the valve seat of the one outboard chamber having the fifth port interconnected thereto and to open the valve seat of the other outboard chamber. A pneumatic source is operatively interconnected to one of the valve seat ports and a pneumatically operated device is operatively interconnected to the fifth port. Pneumatic signal means is operatively interconnected to at least one of the remaining ports so as to cause the logic unit to provide a logic function for the system, such function being an AND function, an OR function, a NOT function, a DELAY function, a PULSE SHAPER function, a MEMORY function, an OSCILLATOR function, a FLIP-FLOP function and the like.

Accordingly, it is an object of this invention to provide an improved pneumatically operated logic system having one or more of the novel features set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. I is a perspective view of the logic unit of this invention; I

FIG. 2 is an enlarged cross-sectional view of the logic unit of FIG. I and is taken on line 2-2 of FIG. l;

FIG 3 is an exploded perspective view of the various parts of the logic unit ofFIGS. 1 and 2;

FIG. 4 is a schematic view illustrating an AND logic function;

FIG. 5 is a schematic view illustrating the logic unit of FIG. 2 providing an AND logic function in a pressure system of this invention;

FIG. 6 is a schematic view illustrating an OR logic function;

FIG. 7 is a schematic view illustrating the logic unit of FIG. 2 providing an OR logic function in a pressure systemofthis invention;

FIG. 8 is a schematic view illustrating a NOT logic function;

FIG. 9 is a schematic view illustrating the logic unit of FIG. 2 providing a NOT logic function in a-pressure system of this invention;

FIG. 10 is a schematic view illustrating a DELAY logic function; I

FIG. 11 is a schematic view illustrating the, logic unit of FIG. 2 providing a DELAY logic fiinction in a pressure system of this invention;

FIG. 12 is a schematic view illustrating a DIFFERENTIA- TOR logic function;

FIG. 13 is a schematic view illustrating the logic unit of FIG. 2 providing a PULSE SI-IAPER logic function in a pressure system of this invention;

FIG. 14 is a schematic view illustrating two logic units of FIG. 2 providing an OSCILLATOR logic function in a pressure system of this invention;

FIG. 15 is a schematic view illustrating a MEMORY logic function;

FIG. 16 is a schematic view illustrating two logic units of FIG. 2 providing a MEMORY logic function in a pressure system of this invention;

FIG. 17 is a schematic view illustrating a FLIP-FLOP logic function;

FIG. 18 is a schematic view illustrating three logic units of FIG. 2 providing a FLIP-FLOP logic function in a pressure system of this invention;

FIG. 19 is a schematic view illustrating a control system for a fuel burning clothes dryer utilizing three logic units of FIG. 2 for performing logic functions in controlling the dryer burner;

FIG. 20 is a schematic view illustrating the logic function of the system of FIG. 19;

FIG. 21 is a schematic view illustrating the logic unit of FIG. 2 providing an AND logic function in a vacuum system of this invention;

FIG. 22 is a schematic view illustrating the logic unit of FIG. 2 providing an OR logic function in a vacuum system of this invention;

FIG. 23 is a schematic view illustrating the logic unit of FIG. 2 providing a NOT logic function in a vacuum system of this invention;

FIG. 24 is a schematic view illustrating the logic unit of FIG. 2 providing a DELAY logic function in a vacuum system of this invention;

FIG. 25 is a schematic view illustrating the logic unit of FIG. 2 providing a PULSE SHAPER logic function in a vacuum system of this invention;

FIG. 26 is a schematic view illustrating two logic units of FIG. 2 providing a MEMORY logic function in a vacuum system of this invention; and

FIG. 27 is a schematic view illustrating three logic units of FIG. 2 providing a FLIP-FLOP logic function in a vacuum system of this invention.

While the various features of this invention are hereinafter illustrated and described as providing certain specific logic functions, it is to be understood that the various novel features of this invention can be utilized singly or in various combinations thereof to provide other pneumatically operated logic systems as desired.

Therefore, this invention is not to be limited only to the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate some of the wide variety of uses of this inventi n.

4 Referring now to FIGS. 1-3, the logic unit of this invention is generally indicated by thereference numeral 40 and is the 'same structure and design as disclosed and claimed in the aforementioned copending US. Pat. application, Ser. No. 772,788, such application merely disclosingsuch unit 40 as a pneumatic valving means and not as provided in this application and in the aforementioned copending parent application, Ser. No. 717,586, of which this application is a Continuationin-Part patent application thereof.

As illustrated in FIGS. 1-3, theunit 40 has a housing means 41 formed from fourhousing parts 42, 43, 44, and 45 secured together in a unique manner hereinafter described to hold a diaphragm member or means 46 in the manner illustrated in FIG. 2 whereby the housing parts 42-45 and the diaphragm means 46 cooperate together to define a plurality ofchambers 47, 48, 49 and 50 in axially stacked relation.

Thehousing member 42 is substantially cup-shaped so as to define aclosed end wall 51 and anopen end 52, theopen end 52 being beveled at 53 completely aroundtheopen end 52 with theannular bevel 53 leading to a substantiallycylindrical cavity 54 being defined by a substantially cylindrical interior wall means 55. Anannular groove 56 is formed in the cylindrical wall means 55 adjacent theopen end 52 to snap-fittingly receive an outward directedannular tongue 57 of thehousing member 45 to secure the housing members 42-45 and diaphragm means 46 together as illustrated in FIG. 2.

Thehousing members 43 and 44 are substantially identical in construction with thehousing member 44 being inverted relative to the housing member 43 and being rotated 180 relative thereto in the assembled condition illustrated in FIG. 2.

The like sides 58 of thehousing members 43 and 44 have an annular recessedshoulder 59 joining anopening 60 passing completely and centrally therethrough and adjoining an annular recessedshoulder 61 in theopposite sides 62 thereof, thesides 62 of thehousing members 43 and 44 each being provided with anannular groove 63 for a purpose hereinafter described. Thehousing members 43 and 44 each has an integral, outwardly extendingtubular projection 64' and 64 extending from thesides 58 thereof with suitable passage or port means 65 and 65 passing therethrough and being interconnected adjacent the juncture of theannular recesses 61 with thesides 62 thereof.

Theclosed end wall 51 of the outboard housing part ormember 42 has aninside surface 66 provided with an inwardly directed, substantially frustoconical valve seat means 67 interconnected to the exterior thereof by a passage or port means 68 in an outwardly directed, integraltubular projection 69, thesurface 66 being interrupted by a recess 70 that is interconnected by passage or port means 71 to the exterior of thehousing member 42 through an integral nipple means ortubular projection 72, the nipple means 69 and 72 having a reinforcingridge 73 interconnecting the same together as illustrated in FIGS. 1 and 2. An inwardly directedannular ridge 74 is concentrically disposed about the valve seat means 67.

The otheroutboard housing member 45 has a substantially flatinner surface 75 carrying an inwardly directed substantially frustoconical valve seat means 76 interconnected to the exterior thereof by a passage orportmeans 77 extending through an outwardly directed integraltubular projection 78. Anannular ridge 79 similar to theannular ridge 74 of thehousing member 42 is concentrically disposed about the valve seat means 76 and extends inwardly from thesurface 75 of thehousing member 45.

Thehousing members 42 and 45 respectively haveopenings 80 and 81 passing therethrough and adapted to respectively telescopically receive thetubular projections 64 of thehousing members 43 and 44 when the parts are disposed in their assembled relation illustrated in FIG. 2.

Therefore, it can be seen that the housing members 4245 can be formed of plastic materials suitably molded or otherwise formed in a simple and economical manner to provide the valve means 40 of this invention. Of course, the housing members 42-45 can be formed of any other suitable material, as desired.

However, while the housing parts 42-45 are illustrated as being circular, it is to be understood that the same could be of other configurations such as rectangular, square or the like as desired.

The diaphragm means 46 is a one-piece flexible structure having abody portion 82 provided with three outwardly directed and axially spaceddiaphragm portions 83, 84 and 85 with theoutboard diaphragm portions 83 and 85 being coplanar with theopposed sides 86 and 87 of thebody portion 82. The outer peripheral portion of theupper diaphragm portion 83 is provided with an annular bead means 88 similar to an annular bead means 89 on the outer peripheral portion of thelower diaphragm portion 85. The intermediate,larger diaphragm portion 84 has an annular bead means 90 at the outer peripheral portion thereof. Theside 87 of thebody portion 82 is interrupted by a circular opening means 91 that terminates at a surface means 92 in thebody portion 82 that has an outwardly directedcircular projection 93 on the surface.

theannular bead 90 of theintermediate diaphragm portion 84.

is disposed in the cooperatingannular recesses 63 in the abuttingsides 62 of thehousing members 43 and 44, thediaphragm portions 83 and 85 being respectively disposed through the opening means 60 of thehousing members 43 and 44 so that the same have their outerperipheral portions 88 and 89 respectively received against the annular shoulder means 59 on thesides 58 thereof. Thereafter, the assembled togetherinboard housing members 43 and 44 anddiaphragmmeans 46 are inserted into thecavity 54 of the cup-shaped.

housing member 42 so that the tubular projection 64' of the housing member 43 passes through theopening 80 of thehousing member 42 and theannular bead'means 88 of theupper diaphragm portion 83 is disposed outboard of theannular ridge 74 of thehousing member 42. Thereafter, acompression spring 95 is disposed in theopening 91 of the diaphragm means 46 so that oneend 96 of the spring means bears against thesurface 92 of the diaphragm means 46. Thereafter, the remainingoutboard housing member 45 is disposed into thecavity 54 of thehousing member 42 with theopening 81 registering with thetubular projection 64 on thehousing member 44 so that thehousing member 45 can be pushed inwardly and have itsannular tongue 57 camming against thebeveled surface 53 at theopen end 52 of thehousing member 42 to facilitate the snapping of thetongue 57 into theannular groove 56 of thehousing member 42 as illustrated in FIG. 2 whereby the outerperipheral bead 89 of thediaphragm portion 85 is disposed outboard of theannular ridge 79 of thehousing member 45.

In this manner, thediaphragm portion 83 is compressed between theannular ridge 74 of thehousing member 42 and the shoulder means 59 of the housing member 43 to seal thechambers 47 and 48 from each other, thelower diaphragm portion 85 similarly being compressed between theannular ridge 79 on thehousing member 45 and the shoulder means 59 of thehousing member 44 to seal thechambers 50 and 49 from each other. Theintermediate diaphragm portion 84 is compressed between the cooperating surfaces of thesides 62 between their cooperating housing members to assure a sealed condition of the various chambers from each other without requiring auxiliary sealing means.

Since theother end 97 of thecompression spring 95 now bears against thesurface 75 of the assembledhousing member 45, the force of thecompression spring 95 normally tends to move thediaphragm portion 83 upwardly to seal closed the valve seat means 67 from thechamber 47 while opening the valve seat means 76 to thechamber 50. However, when the pressure differential between thechambers 48 and 49 overcomes the force of thecompression spring 95, such pressure differential between thechambers 48 and 49 causes thediaphragm portion 83 to move downwardly in opposition to like from clogging the various passageways and chambers of the valve means 40.

If it is desired to utilize theunit 40 as a valve means as disclosed in the aforementioned U.S. Pat. application, Ser. No. 772,788, it can be seen that thetubular projection 72 can be interconnected to a pneumatically operateddevice 99 while thetubular projection 69 can be interconnected to a pneumatic source 100, the source 100 being a vacuum source or a pressure source as desired. The tubular projection 64' of the housing member 43 can be interconnected to onepneumatic signal source 101 while thetubular projection 64 of thehousing member 44 can be interconnected to anotherpneumatic signal source 102, the nipple means 78 being interconnected to the atmosphere.

Therefore, as long as thesignal sources 101 and 102 being directed respectively to thechambers 48 and 49 are equal or the pressure differential therebetween does not overcome the force of thecompression spring 95, the pneumatic source 100 remains disconnected from the pneumatically operateddevice 99 because thediaphragm portion 83 is closing off thevalve seat 67 and the atmosphere is interconnected through the opened valve seat means 76,chamber 50, passage means 94 andchamber 47 to thedevice 99. However, when the pressure differential between thechambers 48 and 49 exceeds the force of thecompression spring 95 to move the diaphragm means 46 downwardly, thediaphragm portion 83 opens thevalve seat 67 and closes the valve seat means 76 whereby the atmosphere is disconnected from the pneumatically operateddevice 99 and the pneumatic source 100 is interconnected thereto to operate thedevice 99 until a change in thesignal sources 101 and 102 again causes the diaphragm means 46 to move upwardly in the manner illustrated in FIG. 2.

As previously set forth, one of the features of this invention is to provide pneumatically operated logic systems utilizingsuch unit 40 without changes therein regardless of the particular logic function to be performed by the same in a particular pneumatically operated logic system.

Before describing the various systems of this invention, it should be understood that normal air leakage or controlled air leakage, such as by restricted air bleeds, are utilized in the various systems of this invention hereinafter described to prevent a locked up condition of any chamber or device when glepneumatic output 106 whereby whenever bothinputs 104 and 105 are "on, the onput 106 is"on" and when one or more of theinputs 104 and 105 are off, theoutput 106 is only, I,

To produce the AND logicfunction with'the unit 40 of this invention, reference is made to FIG. 5 wherein a fluid pressure operated logic system of this invention is generally indicated by thereference numeral 107 and comprises thelogicunit 40 of this invention having its fifth means 7l-fluidly interconnected to a fluid pressure operated.device 108. A pressure fluid source 109 is provided and is disposed in fluid communication with theports 68 and 65' of theunit 40 respectivelyby control means 110 and 11. Theports 65 and 77 of theunit 40 are respectively interconnected to the atmosphere.

Therefore, it can be seen that the atmosphere is interconnected to the outboard chamber 50'when thevalve seat 76 is opened by thediaphragm member 46 being in its normally urged position to close thevalve seat 67 and that the atmosphere is interconnected to theintermediate chamber 49 while the signal means 111 is adapted to be interconnected to theintermediate chamber 48 that is adjacent to theoutboard chamber 47 which is always disposed in fluid communication with the pneumatically operateddevice 108. The pneumatic source 109 is also adapted to be interconnected by the means 110 to thevalve seat 67 of theoutboard chamber 47.

Thus, should both control means 110 and 111 prevent fluid communication between the source 109 and therespective chambers 47 and 48, the compression spring maintains thediaphragm member 46 against thevalve seat 67 so that the atmosphere in theoutboard chamber 50 is interconnected to the pneumatically operateddevice 108 through the opening means 94 that passes through thediaphragm member 46 to always fluidly interconnect the twooutboard chambers 50 and 47 together. If only the means interconnects the source 109 to thevalve seat 67, thediaphragm member 46 remains in the position illustrated in FIG. 5 so that there is no output pressure signal to the pneumatically operateddevice 108. Conversely, if only themeans 111 interconnects the pneumatic pressure source 109 to thechamber 48, the resulting pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 will move thediaphragm member 46 upwardly in FIG. 5 in opposition to the'force of thecompression spring 95 to open thevalve seat 67 and close thevalve seat 76, but since the control means 110 is preventing fluid communication between the pressure source 109 and theoutboard chamber 47, no output pressure signal is directed by theunit 40 to the pneumatically operateddevice 108.

Thus, it can be seen that it requires both means 110 and 111 to respectively direct signals from the pneumatic source 109 to thechambers 47 and 48 to produce a pressure output signal to the pneumatically operateddevice 108 because the signal from the control means 111 moves thediaphragm member 46 upwardly to openvalve seat 67 and the control means 110 provides the pressure signal to thevalve seat 67 to pass therethrough to thedevice 108, whereby the pneumatically operatedlogic system 107 of this invention provides the AND logic function.

In order to illustrate the AND function of theunit 40 of this invention when utilized with a vacuum system, reference is now made to FIG. 21 wherein a vacuum operated logic system of this invention is generally indicated by thereference numeral 107A and parts thereof similar to thesystem 107 of FIG. 5 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIG. 21, thelogic unit 40 of thesystem 107A is identical to thelogic unit 40 of thesystem 107 previously described. However, thevacuum source 109A is adapted to be respectively interconnected by the control means 110A and 111A to theports 68 and 65 of theunit 40 while the vacuum operateddevice 108A is interconnected to theport 71 of theunit 40, theports 65 and 77 being interconnected to the atmosphere.

Therefore, it can be seen that thesystem 107A will prevent any vacuum output signal to thedevice 108A if one or both control means 110 and 111A preventfluid communication between the vacuu'E: source 109A and theirrespective cham- ..bers 47 and 49 oft e unit 40.

terconnected to the atmosphere through the opening means 94 in thediaphragm member 46. With only the means 110A interconnecting thevacuum source 109A to thevalve seat 67,

'thediaphragm member 46 remains in its closed position against thevalve seat 67 so that no vacuum output is directed to thedevice 108A. Conversely, with only the means 111A interconnecting thevacuum source 109A to thechamber 49, the resulting pressure difierential across theintermediate diaphragm portion 84 of thediaphragm member 46 causes thediaphragm member 46 to move upwardly to close thevalve seat 76 and open thevalve seat 67, but since the vacuum .source 109A is not interconnected to thevalve seat 67 by the means 110A, no vacuum output signal is interconnected to the vacuum operateddevice 108A until the means 110A also interconnects thevacuum source 109A to thevalve seat 67 while the means 111A is interconnecting thevacuum source I 109A to thechamber 49 to move thevalve member 46 upwardly.

In this manner, it can be seen that thelogic unit 40 can provide an AND logic function for a vacuum operated system.

Thelogic unit 40 of FIG. 2 can also perform the OR logic function schematically. illustrated in FIG. 6 and generally indicated by thereference numeral 112 wherein theOR unit 112 has twoinputs 113 and 114 and one output 115, the OR function of theOR unit 112 always providing the output 115 when any one or more of theinputs 113 and 114 are on. However, the output 115 is off only if all of theinputs 113 and 114 are off. f

Accordingly, thelogic unit 40 of this invention is schematicallyillustrated in FIG. 7 for providing an OR logic function in a pressure operatedsystem 116 of this invention which comprises a fluid pressure source l17'that is directly interconnected to theport 68 that leads to thevalve seat 67 of theoutboard chamber 47 and is respectively interconnected by a first control means 118 and a second control means 119 to theports 77 and 65' whereby the first control means 118 is adapted to direct a pressure signal to the otheroutboard chamber 50 of theunit 40 and the second control means 119 is adapted to direct a pressure signal to theintermediate chamber 48 that is adjacent to the oneoutboard chamber 47. The otherintermediate chamber 49 is interconnected to the atmosphere at theport 65 and a pressure operateddevice 120 is interconnected to thefifth port 71 of theunit 40 so as to always be disposed in fluid communication with the oneoutboard chamber 47. Accordingly, it can be seen that when one or both of the control means 118 and 119 are directing a pressure signal to theunit 40, a pressure output is directed to thedevice 120 and when neither control means 118 and 119 are directing a pressure signal to theunit 40, no pressure output is directed to thedevice 120.

In particular, with thepressure source 117 operating and the control means 118 and 119 preventing fluid communication respectively to thechambers 50 and 48 of theunit 40, thediaphragm member 46 of theunit 40 is closing thevalve seat 67 by the force of the urging means 95 whereby thepressure source 117 is prevented from being directed to thedevice 120 and since no pressure exists in theoutboard chamber 50, thechamber 50 also does not direct a pressure output to thedevice 120 through the passage means 94 of thediaphragm member 46. However, when only the first control means 118 is-directing a pressure signal to theoutboard chamber 50, it can be seen that such pressure signal passes through the opening means 94 of thediaphragm member 46 to theoutboard chamber 47 and, thus, to thedevice 120. However, if the second control means 119 is directing a pressure signal to theintermediate chamber 48, regardless of whether the first control means 118 is directing a pressure signal to theoutboard chamber 50 or not, the resulting pressure difierential across theintermediate diaphragm portion 84 of the diaphragm means 46 overcomes the force of the compression spring and moves thediaphragm member 46 upwardly to open thevalve seat 67 and close thevalve seat 76 whereby the openedvalve seat 67 directly interconnects thepneumatic source 117 to thedevice 120. Therefore, it can be seen that thelogic unit 40 of this invention is adapted to provide an OR logic function for a pressure operated system. M

Reference is now made to FIG. 22 wherein thelogic unit 40 of this invention is adapted to provide an OR logic function in a vacuum operated system of this invention that is generally indicated by thereference numeral 116A and parts of the.

to thevalve seat 67 thereof. Thevacuum source 117A is also. adapted to be respectively interconnected by first control? means 118A and second control means 119A to theports 77 and 65 of theunit 40 so that the control means 118A is adapted to direct a vacuum signal to theoutboard chamber 50 through thevalve seat 76 thereof and the control means 119A is adapted to direct a vacuum signal to theintermediate chamber 49 that is adjacent to theoutboard chamber 50, the otherintermediate chamber 48 being interconnected to the atmosphere at theport 65 and the vacuum operateddevice 120A being interconnected to thefifth port 71 of theunit 40 so as to always be in fluid communication with theoutboard chamber 47.

With thevacuum source 117A operating and the control means 118A and 119A each failing to direct a vacuum signal to therespective chambers 50 and 49, the urging means 95 maintains thediaphragm member 46 against thevalve seat 67 so that no vacuum output is directed to the vacuum operateddevice 120A. However, if only the first control means 118A is directing a vacuum signal to theoutboard chamber 50, such vacuum signal in thechamber 50 is interconnected to thedevice 120A because of the opening means 94 through thediaphragm member 46.

However, if the second control means 119A is directing a vacuum signal to theintermediate chamber 49, regardless of whether the first control means 118A is directing a vacuum signal to theoutboard chamber 50 or not, the resulting pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 overcomes the force of thecompression spring 95 and moves thediaphragm member 46 to close thevalve seat 76 and open thevalve seat 67 whereby thevacuum source 117A is interconnected to thedevice 120A.

Therefore, it can be seen that thelogic unit 40 of this invention can provide an OR logic function in either a pressure operated system or a vacuum operated system without any change in the structure thereof.

Referring now to FIG. 8, a conventional logic arrangement is generally indicated by thereference numeral 121 and illustrates schematically a NOT logic function that has oneinput 122 and oneoutput 123, theunit 121 functioning so that theoutput 123 is on when theinput 122 is off and, converse- 1y, iftheinput 122 is on", theoutput 123 is of Accordingly, thelogic unit 40 of this invention is adapted to provide the above described NOT logic function and is illus trated in FIG. 9 as being in apressure system 124 of this invention wherein apneumatic pressure source 125 is directlyinterconnected to theport 77 and a control means 126 is adapted to interconnect thesource 125 to theport 65' that leads to theintermediate chamber 48 that is adjacent to the oneoutboard chamber 47 that has itsport 71 interconnected to a pressure operateddevice 127 and has itsvalve seat port 68 interconnected to the atmosphere. Theport 65 is also interconnected to the atmosphere. 5 Thus, it can be seen that when the control means 126 prevents a pressure input signal means to thechamber 48 of theunit 40, thecompression spring 95 maintains thediaphragm member 46 against thevalve seat 67 while maintaining thevalve seat 76 in an open condition so that thepneumatic pressure source 125 is interconnected to thedevice 127 by passing through the opening means 94 in thediaphragm member 46. However, when the control means 126 directs a pressure input signal means to thechamber 48 of theunit 40, the resulting pressure differential across theintermediate diaphragm portion 84 overcomes the force of thecompression spring 95 and moves thediaphragm member 46 upwardly to close thevalve seat 76 and open thevalve seat 67 whereby thesource 125 is disconnected from thedevice 127 and thedevice 127 is interconnected to the atmosphere through the openedvalve seat 67 and theport 68.

Therefore, it can be seen that thesystem 124 of this invention utilizes theunit 40 to provide a NOT logic function because the output to thedevice 127 is only provided when the control means 126 does not provide an input pressure signal means to thedevice 40 and, conversely, thedevice 127 does not have any output pressure directed thereto when the control means 126 directs an input pressure signal means to theunit 40. i

Referring now to FIG. 23, a vacuum operated logic system is generally indicated by thereference numeral 124A and parts thereof similar to thesystem 124 of FIG. 9 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIG. 23, thevacuum source 125A is directly interconnected to theport 77 of theunit 40 and is adapted to be interconnected by the control means 126A to theport 65 of theunit 40 that leads to theintermediate chamber 49 that is adjacent to theoutboard chamber 50, theports 68 and 65' being interconnected to the atmosphere while thefifth port 71 of theunit 40 is" interconnected to a vacuum operateddevice 127A.

Thus, when the control means 126A is not directing a vacuum input signal to theintermediate chamber 49 of theunit 40, thecompression spring 95 maintains thediaphragm member 46 against thevalve seat 67 while maintaining thevalve seat 76 open so that thevacuum source 125A is interconnected to the vacuum operateddevice 127A through the opening means 94 in thediaphragm member 46. However,

. when the control means 126A is directing a vacuum input signal to thechamber 49 of theunit 40, the resulting pressure differential across theintermediate diaphragm portion 84 overcomes the force of thecompression spring 95 and moves thediaphragm member 46 upwardly to open thevalve seat 67 and close thevalve seat 76 so that thevacuum source 125A is disconnected from thedevice 127A and thedevice 127A is interconnected to the atmosphere through the openedvalve seat 67.

Therefore, it can be seen that the vacuum operatedlogic system 124A of FIG. 23 utilizes theunit 40 to provide a NOT logic function without any changes in the structure of thelogic unit 40.

Referring now to FIG. 10, a conventional DELAY logic arrangement is generally indicated by thereference numeral 128 and is adapted to function in sucha manner that when aninput signal 129 is initially turned on, theoutput signal 130 will not occur until after a predetermined time period. Conversely, when theinput signal 129 is initially terminated, theoutput signal 130 is not terminated until after a predetermined time period.

Accordingly, reference is now made to FIG. 11 wherein thelogic unit 40 of this invention is utilized in a pressure logic system that is generally indicated by thereference numeral 131 to provide the previously described DELAY logic function, thesystem 131 comprising a pressure source 132 interconnected to theport 68 of theunit 40 and a pressure operateddevice 133 interconnected to thefifth port 71 of theunit 40 while theports 65 and 77 are connected to the atmosphere. A control means 134 is adapted to interconnect the source 132 to theport 65 of theunit 40 that leads to theintermediate chamber 48. However, arestrictor 135 and anaccumulator 136 are disposed in series between the control means 134 and theport 65 for a purpose now to be described.

lf control means 134 is preventing fluid communication between the source 132 and theport 65, the urging means maintains thediaphragm member 46 against thevalve seat 67 so that the source 132 is prevented from being interconnected to thedevice 133 and thedevice 133 is disposed in fluid communication with the atmosphere through the passage means 94 of thediaphragm member 46 and the openedvalve seat 76.

When the control means 134 initially directs a pressure signal from the source 132 toward theport 65' of theunit 40, the restriction andaccumulator 136 prevent a buildup of pressure in theintermediate chamber 48 for a delayed time period after the lapse of which the pressure buildup in theintermediate chamber 48 results in a pressure differential across theintermediate diaphragm portion 84 that moves thediaphragm member 46 upwardly in opposition to the force of thecompression spring 95 to close thevalve seat 76 and open thevalve seat 67 so that the pressure source 132 is interconnected to the pressure operateddevice 133 through the openedvalve seat 67. 7

Conversely, when the control means 134 initially terminates the pressure signal to theport 65' after thediaphragm member 46 has been moved upwardly in the manner previ ously described, theaccumulator 136 andrestrictor 135 function to maintain a sufficient pressure in theintermediate chamber 48 to maintain thediaphragm member 46 in its up position against thevalve seat 76 for 'a predetermined time period after the lapse of which the dissipation of the pressure in theintermediate chamber 48 by the previously described air leakage is sufficient to permit the urging means 95 to move thediaphragm member 46 downwardly to close thevalve seat 67 and open thevalve seat 76 so that the source 132 is disconnected from thedevice 133.

Therefore, it can be seen that theunit 40 of this invention provides a DELAY logic function wherein the pressure output to the pressure operateddevice 133 is delayed for a predetermined time period from the time that a pneumatic pressure signal is initially directed to theunit 40. Conversely, theunit 40 continues to provide a pressure signal to thedevice 133 for a predetermined time period after the pneumatic pressure signal to theunit 40 is terminated.

Referring now to FIG. 24, thelogic unit 40 of this invention is illustrated in a vacuum operated logic system that is generally indicated by thereference numeral 131A for providing the aforedescribed DELAY logic function, the parts of thesystem 131A similar to thesystem 131 of FIG. 11 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIG. 24, thevacuum source 132A is directly interconnected to theport 68 of thelogic unit 40 and the vacuum operated device 133A is interconnected to thefifth port 71 of theunit 40. Theports 77 and 65 of theunit 40 are directly interconnected to the atmosphere. A .control means 134A is adapted to interconnect thesource 132A to theport 65 of theunit 40 that leads to theintermediate chamber 49. However, arestrictor 135A andaccumulator 136A are disposed in series between the control means 134A and theport 65.

If the control means 134A is in an off condition thereof, the urging means 95 maintains thediaphragm member 46 against thevalve seat 67 so that thevacuum source 132A is prevented from being interconnected to the device 133A which is at atmospheric condition because of the passage means 94 through thediaphragm member 46 and the openedvalve seat 76.

When the control means 134A initially directs a vacuum signal from thesource 132A toward theport 65, therestrictor 135A andaccumulator 136A function in a manner to prevent an effective evacuation of thechamber 49 for a predetermined time period after the lapse of which the evacuation of thechamber 49 results in a pressure differential across theintermediate diaphragm portion 84 sufficient to move thediaphragm member 46 upwardly in opposition to the force of thecompression spring 95 to open thevalve seat 67 and close thevalve seat 76 so that thevacuum source 132A is now interconnected to the device 133A.

Conversely, when the control means 134A initially disconnects thevacuum source 132A from theport 65 of theunit 40 after thediaphragm member 46 has been moved upwardly to close thevalve seat 76 in the manner previously described, therestrictor 135A andaccumulator 136A function to prevent a sufficient return of air to thechamber 49 through the previously described air leakage means for a predetermined time period after the lapse of which the resulting decrease in pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 permits thecompression spring 95 to move thediaphragm member 46 downwardly to close thevalve seat 67 and open thevalve seat 76 so that thevacuum source 132A is disconnected from the vacuum operated device 133A.

7 Therefore, it can be seen that thelogic unit 40 of this invention can be utilized in a pressure or a vacuum system to provide a DELAY logic function without any change in the structure thereof.

FIG. 12 schematically illustrated a logic arrangement that is generally indicated by thereference numeral 137 and that provides a PULSE SHAPER logic function somewhat similar to a DIFFERENTIATOR logic function wherein aninput signal 138 initially directed to thelogic unit 137 will create anoutput signal 139 only for a short duration of time after the lapse of which theoutput signal 139 is terminated even though theinput signal 138 continues in an on condition after the lapse of the time period that theoutput signal 139 was on.

Referring now to FIG. 13, thelogic unit 40 of this invention is utilized in a fluid pressure system that is generally indicated by thereference numeral 140 to provide the aforementioned PULSE SI-IAPER logic function, thesystem 140 of this invention comprising a fluid pressure source 141 adapted to be interconnected by a control means 142 to theport 77 of theunit 40 and to a signal means conduit 143 that leads to theport 65' of theunit 40. However, the signal means conduit 143 has arestriction 144 therein intermediate the control means 142 and theport 65. The pressure operateddevice 145 is interconnected to thefifth port 71 of theunit 40 while theports 68 and 65 are respectively interconnected to the atmosphere.

When the control means 142 initially interconnects the pressure source 141 to theport 77 and to the signal means conduit 143, therestrictor 144 prevents a buildup of pressure in theintermediate chamber 48 sufficient to overcome the force of thecompression spring 95 for a predetermined time period whereby during such time period, the pressure source 141 is directly interconnected to the pressure operateddevice 145 through the openedvalve seat 76 and the passage means 94 through thediaphragm member 46. However, after the lapse of such time period, the buildup of pressure in thechamber 48 is such that the same results in a pressure difi ferential across theintermediate diaphragm portion 84 of thediaphragm member 46 to move thediaphragm member 46 upwardly in opposition to the force of thecompression spring 95 to close thevalve seat 76 and open thevalve seat 67 whereby the pressure source 141 is disconnected from the pressure operateddevice 145 which is now interconnected to the atmosphere through the openedvalve seat 67. Thus, the

diaphragm member 46 now remains in its up position closing thevalve seat 76 as long as the signal means is being directed to theintermediate chamber 48 after the lapse of the aforementioned time period, 1

Therefore, it can be seen that thelogic unit 40 of this invention is adapted to provide a PULSE SHAPER logic function in Y a pressure system of this invention. Referring now to F 1G. 25, thelogic unit 40 of this invention is schematically illustrated in a vacuum operated logic system I that is generally indicated by thereference numeral 140A with thesystem 140A providing the PULSE SHAPER logic function, the various parts of thesystem 140A similar to the system of FIG. 13 are indicated by likereference numerals followed by the reference letter A.

As illustrated in FIG. 25, the vacuum source 141A is directly interconnected to theport 68 of thelogic unit 40 and a control means 142A is adapted to interconnect the source 141A to theport 65 of theunit 40. The vacuum operated device A is interconnected by a conduit means 146 to thefifth port 71 of thelogic unit 40 while theport 77 thereof is directly interconnected to the atmosphere.

A conduit means 147 interconnects theconduit 146 intermediate the vacuum operateddevice 145A and theport 71 to theport 65 of theunit 40, the conduit'rneans having arestrictor 148 and anaccumulator 149 in series therein intermediate theconduit 146 and theport 65.

When the control means 142A is in an"off" condition so that the vacuum source 141A is disconnected from the inter mediatechamber 49, thecompression spring 95 maintains thediaphragm member 46 closed against thevalve seat 67 so that the vacuum source 141A is disconnected fromthe vacuum operateddevice 145A which is interconnected to the atmosphere through the passage means 94 of thediaphragm member 46 and the openedvalve seat 76..

However, when the control means 142A initially interconnects the vacuum source 141A to theintermediate chamber 49, the resulting pressure differential across theintermediate diaphragm portion 84 causes thediaphragm member 46 to move upwardly in opposition to the force of thecompression spring 95 to open thevalve seat 67 and close thevalve seat 76 so that the vacuum source 141A is interconnected to the vacuum operateddevice 145A.

However, with the vacuum source 141A now interconnected to the vacuum operateddevice 145A, therestrictor 148 andaccumulator 149 in the conduit means 147 prevents evacuation of theintermediate chamber 48 to such a degree that the same counterbalances the evacuation'of thechamber 49 until after the lapse of a predetermined time period. At the lapse of the predetermined time period, the decrease in the pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 is such that the compres-v sion spring 95 moves thediaphragm member 46 downwardly to close thevalve seat 67 and open thevalve seat 76 so that the vacuum source 141A is disconnected from the vacuum operateddevice 145A whereby thediaphragm member 46 will remain in its down position closing off thevalve seat 67 as long as the control means 142A continues to direct the vacuum source 141A to theintermediate chamber 49 after the lapse of the aforementioned predetermined time period until thechamber 48 returns to atmospheric condition so that the vacuum signal inchamber 49 can again cause thediaphragm member 46 to move upwardly and repeat the PULSE SHAPER logic function in the manner previously described.

Therefore, it can be seen that thelogic unit 40 of this invention can be utilized to produce a PULSE SHAPER logic function in a pressure system or a vacuum system without a change in the structure thereof.

Referring now to FIG. 14, a fluid pressure operated logic system of this invention is generally indicated by thereference numeral 195 and combines afirst logic unit 40 and a likesecond logic unit 40A to produce an OSCILLATOR logic function, thesystem 195 comprising a fluid pressure source 196 interconnected to theport 68 of theunit 40 and being adapted to be interconnected by a control means 197 through a restrictor 198 to theport 65 of theunit 40 and to theport 68 of theother unit 40A. The pressure operateddevice 199 is interconnected to thefifth port 71 of theunit 40 and a passage means having a restrictor 151 therein interconnects theport 65 of theother unit 40A to a conduit means 152 that interconnects thefifth port 71 of theunit 40 to the pressure operateddevice 199.

The system therefore utilizes theunit 40A as a MEMORY logic unit and theunit 40 as an AND logic unit to combine the same to provide an OSCILLATOR logic function that can be defined as having one input and one output so that when the input is on, the output will oscillate on and off at a predetermined frequency.

In particular, it can readily be seen in FIG. 14 that when the control means 197 is in an off condition so that no pressure fluid is being delivered to theport 65 of the ANDunit 40 and to theport 68 of theMEMORY unit 40A bothdiaphragm members 46 are respectively held against the valve seats 67 so that the pressure source 196 cannot deliver a pressure output to the pressure operateddevice 199 which is at atmospheric conditions because of the openedvalve seat 76 of theunit 40 and the passage means 94 through thediaphragm member 46 thereof.

However, when thecontrol device 197 delivers a pressure signal through the restrictor 196 to theport 65 of theunit 40 and to theport 68 of theunit 40A, the resulting pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 of theunit 40 overcomes the force of thecompression spring 95 so that thediaphragm member 46 of theunit 40 moves upwardly to open thevalve seat 67 and close thevalve seat 76 so that the pressure source 196 is now interconnected to the pressure operateddevice 199. Simultaneously the pneumatic signal means is being directed to theport 68 of theunit 40A but because thediaphragm member 46 thereof is closing thevalve seat 67, the pressure signal means is not dissipated out through thefifth port 71 of the device of theunit 40A. With pressure fluid now being delivered to thedevice 199, it can be seen that the passage means 150 will, after a predetermined time period, deliver'sufficient pressure fluid through the restrictor 151 to theport 65 of theunit 40A so that the resulting pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 of theunit 40A will cause thediaphragm member 46 to move upwardly in opposition to the force of thecompression spring 95 to open thevalve seat 67 so that the pneumatic signal means will now be dissipated through the openedvalve seat 67 to the atmosphere through theport 71 of theunit 40A. In this manner, the pressure fluid in theintermediate chamber 48 of theunit 40 will be dissipated and thecompression spring 95 will move thediaphragm member 46 of theunit 40 downwardly to again close thevalve seat 67 and thereby terminate the flow of pressure fluid from the source 196 to thedevice 199. Thediaphragm member 46 of theunit 40A remains in its up position until the pressure fluid in theintermediate chamber 48 thereof dissipates sufiiciently through the aforementioned air leakage means so that thecompression spring 95 will move thediaphragm member 46 downwardly to again close thevalve seat 67 of theunit 40A and thereby again permit a pressure buildup of the signal .means in theintermediate chamber 48 of theunit 40 to again open thevalve seat 67 thereof and interconnect the source 196 again to thedevice 199.

Therefore, it can be seen that as long as the control means 197 is delivering a pressure signal means through therestrictor 198, the output to thedevice 199 will oscillate on and off at a predetermined frequency provided by the restrictor 151 in the conduit means 150 so that the pressure operatedlogic system 195 provides an OSCILLATOR logic function utilizing twounits 40 of this invention without changes in the structure thereof.

Referring now to FIG. 15, a logic means 153 is schematically illustrated for producing a MEMORY logic function, the MEMORY means 153 having twoinputs 154 and 155 and oneoutput 156 so that when only theinput 154 is in an on condition, theunit 153 produces theoutput 156 and will maintain theoutput 156 even though theinput 154 is subsequently terminated whereby theoutput 156 continues until theother input 155 is turned on to cause theunit 153. to terminate theoutput 156. Thus, it can be seen that theunit 153 provides the MEMORY logic function of remembering that theinput 154 was initially on" so as to continue to produce theoutput 156 until thereset input 155 is imposed thereon.

Thelogic unit 40 of this invention can be utilized in thepressure system 157 of FIG. 16 to produce the aforementioned MEMORY function in a manner now to be described.

161 interconnects theport 68 of theother unit 40A to the signal means of the first control means 159 intermediate thecheck valve 160 and theport 65 of theunit 40.

A pressure operateddevice 162 is interconnected to thefifth port 71 of theunit 40 by passage means 163. A second passage means 164 interconnects the passage means 163 intermediate theport 71 and thedevice 162 through a restrictor 165 to the signal means of the control means 159 intermediate thecheck valve 160 and theport 65 of theunit 40.

A second control means 166 is adapted to interconnect a pressure signal means to theport 65 of theother unit 40A.

With both control means 159 and 166 in their off condition, it can be seen that bothdiaphragm members 46 of theunits 40 and 40A are respectively closing the valve seats 67 thereof so that thesource 158 is completely disconnected from thedevice 162 and thedevice 162 is at atmospheric condition because of the openedvalve seat 76 of theunit 40 and the opening means 94 through thediaphragm member 46 thereof.

However, when the first control means 159 is initially turned on" to direct a pressure signal through the one-way check valve 160 to theport 65 of theunit 40, the resulting pressure differential across theintermediate diaphragm portion 84 of thediaphragm member 46 of theunit 40 overcomes the urging means 95 thereof to open thevalve seat 67 of theoutboard chamber 47 to not only interconnect thepressure source 158 to thedevice 162, but also to supply sufficient pressure through therestrictor 165 of the passage means 164 to theintermediate chamber 48 of theunit 40 to maintain thediaphragm member 46 thereof in its up condition so that thesource 158 will be continuously interconnected to thedevice 162 even though the first control means 159 is subsequently turned to its off" condition, the passage 16] being closed from the atmosphere by thediaphragm member 46 of theunit 40A.

Thus, once the control means 159 has been turned to an on position thereof, theunit 40 maintains an interconnection between thesource 158 and thedevice 162 until the second control means 166 is turned on" and directs a pressure signal to theport 65 of theunit 40A to produce a pressure differential across theintermediate diaphragm portion 84 thereof that overcomes the urging means 95 thereof and moves thediaphragm member 46 thereof upwardly to open thevalve seat 67 of theunit 40A so that thepassage 161 is interconnected to the atmosphere through theport 71 of theunit 40A and such interconnection will dissipate the pressure in theintennediate chamber 48 of theunit 40 sufficiently so that the urging means .95 will move thediaphragm member 46 of theunit 40 downwardly to close thevalve seat 67 and thereby terminate the interconnection of thesource 158 to thedevice 162.

Therefore, it can be seen that the pressure operatedlogic system 157 of FIG. 16 provides a MEMORY logic function previously described.

Such logic units 40 can be utilized in a vacuum system of this invention to provide the aforementioned MEMORY logic function.

For example, reference is now made to FIG. 26 wherein a vacuum operated logic system of this invention is generally indicated by thereference numeral 167 and provides a MEMORY logic function with afirst logic unit 40 and asecond logic unit 40A, the parts of thesystem 167 similar to parts of thesystem 157 of FIG. 16 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIG. 26, thevacuum source 158A is directly interconnected to theport 68 of thefirst unit 40 and a 75 Efirst control means 159A is adapted to interconnect a vacuum 'A first passage means 168 interconnects the signal means of the first control means 159A intermediate thecheck valve 160A and theport 65 of theunit 40 to thepassage 163A intermediate the device 162A and theport 71 of theunit 40, thepassage 168 having a restrictor 169 therein.

A second passage means 171) interconnects theport 68 of I theother unit 40A to the first passage means 168 intermediate therestrictor 169 thereof and thecheck valve 160A.

A second control means 166A is adapted to. interconnect a vacuum signal means to theport 65 of theother unit 40A.

when the control means 159A and 166A are in an off" condition thereof, it can be seen that thediaphragm members 46 .of theunits 40 and 40A are respectively closing the valve seats 67 so that thevacuum source 158A is disconnected from lthegdevice 162A and the device 162Ais at atmospheric conditioii because of theopen valve seat 76 of theunit 40 and the opening means 94 through thediaphragm member 46 thereof.

However, when only the control means 159A is turned to an on" condition thereof to direct a vacuum signal through the one-way check valve 160A to the intermediate chamber 49 of the unit 40 to overcome the urging means 95 and cause the diaphragm member 46 to move upwardly and open the valve seat 67, not only is the vacuum source 158A interconnected to the device 162A, but also the vacuum source 158A is interconnected by the first passage means 168 to the intermediate chamber 49 of the unit 40 to lock the diaphragm member 46 in its up position even if the first control means 159A is subsequently turned to an off condition thereof whereby the vacuum source 158A is continuously interconnected to the device 162A as long as the second control means 166A is in an of the diaphragm member 46 thereof to overcome the compression spring 95 whereby the diaphragm member 46 moves upwardly to open the valve seat 67, it can be seen that the second passage 170 is now interconnected to the atmosphere through the fifth port 71 of the unit 40A so that air is now permitted to return to the intermediate chamber 49 of the unit 40 so that the urging means 95 of the unit 40 will move the diaphragm member 46 thereof downwardly to again close the valve seat 67 and thereby terminate the interconnection between the vacuum source 158A and the device 162A.

Accordingly, it can be seen that the vacuum operatedlogic system 167 of this invention utilizes twoidentical logic units 40 and 40A of this invention to produce a MEMORY logic function as previously described.

Reference is now made to FIG. 17 wherein another logic arrangement is generally indicated by thereference numeral 171 and is utilized for providing a FLIP-FLOP logic function that has two input signal means 172 and 173 and twooutputs 174 and 175, thearrangement 171 being such that when the input 172 is on, only theoutput 174 is on." However, when the input 173 is on," theoutput 174 is off and theoutput 175 is on.

such F LIP-F LOP logic function can be provided by utilizing thelogic units 40 of this invention in the manner illustrated in F 1G. 18 wherein a fluid pressure logic system of this invention is generally indicated by thereference numeral 176 and comprises afirst logic unit 40, asecond logic unit 40A and athird logic unit 40B, thelogic units 40, 40A and 4013 being identical without any changes in the structure thereof.

The pressure source for thesystem 176 is indicated by thereference numeral 177 and is directly interconnected to theport 68 of theunit 40 and to theport 77 of thesecond unit 40A. A first control means 178 is adapted to interconnect a pressure signal means through a one-way check valve means 179 to theport 65' of theunit 40. A second control means 180 is adapted to interconnect its pressure signal means to theport 65 of the third unit 408. A first pressure operateddevice 181 is interconnected to thefifth port 71 of thefirst unit 40 bya conduit means 182. A second pressure operateddevice 183 is v interconnected to theport 71 of thesecond unit 40A. A first passage means 184 interconnects theport 68 of th third unit 4013 to theport 65' of the,second unit 40A and to I the single means of the first control means 178 intermediate thecheck valve 179 and theport 65 of thefirst unit 40.

A second passage means 185 having a restriction 191 therein interconnects theconduit 182 to the signal means of the first control means 178 intermediate thecheck valve 179 and theport 65 of thefirst unit 40.

Theports 71, 65 and 77 of the third unit 405, theports 65 and 68 of thesecond unit 40A and theports 65 and 77 of thefirst unit 40 are interconnected to the atmosphere.

With thepressure source 177 operating and the control means 178 and 180 being in an off condition, it can be seen that thediaphragm member 46 of thefirst unit 40 is closing thevalve seat 67 so that thesource 177 is not connected to thefirst device 181 and that thedevice 181 is interconnected to the atmosphere through the opening means 94 of thediaphragm member 46 andopen valve seat 76 of theunit 40 while thesecond device 183 is interconnected to thesource 177 through the openedvalve seat 76 of thesecond unit 40A and the opening means 94 passing through thediaphragm member 46 thereof.

However, when only the first control means 178 is turned to an on condition thereof to direct a pressure signal through the one-way check valve 179 through theports 65' of theunits 40 and 40A, the resulting differential in pressure across theintermediate diaphragm portions 84 of thediaphragm members 46 thereof causes thediaphragm members 46 to move upwardly in opposition to the force of the compression springs to respectively open the valve seats 67 thereof and close the valve seats 76 thereof so that thesource 177 is interconnected through theopen valve seat 67 of thefirst unit 40 to thefirst device 181 while thesource 177 is disconnected by theclosed valve seat 76 of thesecond unit 40A from thesecond device 183 which is now interconnected to the atmosphere through the openedvalve seat 67 of thesecond unit 40A.

The second passage means 185 of thesystem 176 cooperates with the one-way check valve 179 to maintain sufficient pressure in theintermediate chambers 48 of theunits 40 and 40A to maintain thediaphragm members 46 thereof in an up condition in FIG. 18 even if the first control means 178 is subsequently turned of after causing an output pressure to the first pneumatically operateddevice 181.

Thus, thesource 177 remains interconnected to thedevice 181 until the second control means is turned to an on" condition thereof to direct a pressure signal means to theintermediate chamber 48 of the third unit 403 to overcome the urging means 95 and cause thediaphragm member 46 to move upwardly to open thevalve seat 67 thereof and close thevalve seat 76 thereof whereby the first passage means 184 is now interconnected to the atmosphere through the openedvalve seat 67 of the unit 4013 through thefifth port 71 thereof.

With the opening of thevalve seat 67 of the third unit 408, it can be seen that the pressure in theintermediate chambers 48 of theunits 40 and 40A is dissipated to the atmosphere so that the urging means 95 respectively cause thediaphragm members 46 of theunits 40 and 40A to move downwardly to close the valve seats 67 thereof and open the valve seats 76 thereof so that the atmosphere is now interconnected to thefirst device 181 through the openedvalve seat 76 and opening means 94 of thediaphragm member 46 of thefirst unit 40 and thesource 177 is now interconnected to thesecond device 183 through theopen valve seat 76 of thesecond unit 40A and the opening means 94 passing through thediaphragm member 46 thereof.

Accordingly, it can be seen that thesystem 176 of this invention provides a FLIP-FLOP logic function utilizing threelogic units 40 of this invention without any changes in the structure of theunits 40.

Reference is now made to FIG. 27 wherein threesuch logic units 40, 40A and 40B are utilized in a vacuum operatedlogic system 186 of this invention for providing the aforementioned FLIP-FLOP logic function. The parts of thesystem 186 that are similar to parts of thesystem 176 of FIG. 18 are indicated by like reference numerals followed by the reference letter A.

In particular, thesystem 186 comprises avacuum source 177A interconnected to theport 68 of thefirst unit 40 and to theport 77 of thesecond unit 40A. A first control means 178A is adapted to interconnect its vacuum signal means through a one-way check valve 179A to theport 65 of thefirst unit 40. A second control means 180A is adapted to interconnect its vacuum signal means to theport 65 of thethird unit 40B.

A first vacuum operateddevice 181A is interconnected by a conduit means 182A to theport 71 of thefirst unit 40 while a second vacuum operateddevice 183A is interconnected to theport 71 of thesecond unit 40A.

A first passage means 187 interconnects the vacuum signal means of the first control means 178A intermediate thecheck valve 179A and theport 65 of thefirst unit 40 to theconduit 182A that interconnects thefifth port 71 of theunit 40 to thefirst device 181A. Thefirst passage 187 has a restriction 188 therein.

A second passage means 189 interconnects theport 65 of thesecond unit 40A to theport 68 of thethird unit 40B and to the first passage means 187 intermediate thecheck valve 179A and the restriction 188.

When both control means 178A and 180A are in an off" condition and thevacuum source 177A is operating, it can be seen that thefirst device 181A is interconnected to the atmosphere through the openedvalve seat 76 of thefirst unit 40 and the passage means 94 through thediaphragm member 46 thereof while thesecond device 183A is interconnected to thevacuum source 177A through the openedvalve seat 76 of thesecond unit 40A and the passage means 94 through thediaphragm member 46 thereof.

However, when only the first control means 178A is turned to an on" condition thereof, the vacuum signal thereof that operates through the one-way check valve 179A respectively evacuates theintermediate chambers 49 of the first andsecond units 40 and 40A so that the resulting pressure differentials across theintermediate diaphragm portions 84 of thediaphragm members 46 thereof overcomes the urging means 95 to move thediaphragm members 46 respectively to open the valve seats 67 thereof and close the valve seats 76 thereof so that thevacuum source 177A is interconnected to thefirst device 181A through the openedvalve seat 67 and thefifth port 71 of theunit 40 and thevacuum source 177A is disconnected from the second device, 183A because of theclosed valve seat 76 of thesecond unit 40A.

Because of the first passage means 187 cooperating with the one-way check valve 179A, sufficient evacuation of theintermediate chambers 49 of theunits 40 and 40A continues to take place even though the first control means 178A may be subsequently turned to an off condition thereof so that thevacuum source 177A will remain interconnected to thefirst device 181A after the first control means 178A has been turned to an on condition thereof until the second control means 180A is turned to an on" condition thereof.

In particular, when the second control means 180A is turned to an on condition thereof to direct a vacuum signal means to theintermediate chamber 49 of thethird unit 40B so that the resulting pressure differential across theintermediate diaphragm portion 84 thereof causes thediaphragm member 46 to move in opposition to the force of the urging means 95 to open thevalve seat 67 and close thevalve seat 76 of theunit 40B, the openedvalve seat 67 of theunit 40B now effectively interconnects the first and second passage means 187 and 189 18 to the atmosphere at the port 717E the unit 408 so that sufficient air now returns to theintermediate chambers 49 of theunits 40 and 40A to cause the urging means 95 to move thediaphragm members 46 respectively against the valve seats 67 thereof whereby theunit 40 disconnects thesource 177A from thefirst device 181A and the openedvalve seat 76 of theunit 40A interconnects thevacuum source 177A to thesecond unit 183A through the opening means 94 of thediaphragm member 46 of theunit 40A.'

Therefore, it can be seen that thevacuum control system 186 of FIG. 27 provides a FLIP-FLOP logic function utilizing threelogic units 40 of this invention without any change in the structure of theunits 40.

Reference is now made to FIG. 19 wherein the dryer control system of the aforementioned copending parent application is illustrated and utilizes three logic units of FIG. 2 in a manner hereinafter described.

As illustrated in FIG. 19, the laundry apparatus is generally indicated by thereference numeral 200 and includes anelectric motor 215 which rotates the clothes-receiving drum (not shown) of theapparatus 200 during the'entire cycle of operation of theapparatus 200 in a conventional manner, theelectric motor 215 being adapted to be interconnected to power source leads L and L in a manner hereinafter described. The electric motor is adapted to drive aneccentric cam 216 connected to itsoutput shaft 217 as long as theelectrical motor 215 is energized whereby theeccentric cam 216 will continuously move apiston rod arrangement 218 to operate a vacuum pump means 219 to provide a continuous vacuum source for the pneumatic logic control system of this invention which is generally indicated by thereference numeral 201 as long as theelectrical motor 215 is energized, thevacuum pump 219 having itsinlet 220 interconnected to a conduit means 221.

The power source lead L is interconnected to a door operated electrical switch blade 222 by alead 223 whereby the switch blade 222 will be closed against a contact 224 only when the access door of thedryer 200 is disposed in its closed position so as to electrically interconnect thelead 223 to a lead 225 that is interconnected to oneside 226 of theelectrical motor 215. Theother side 227 of theelectrical motor 215 is interconnected to a contact 228 by alead 229. An on-offelectrical switch 233 is provided for theapparatus 200, theswitch 233 being automatically operated by a timer means of theapparatus 200 in a conventional manner.

In particular, when the housewife or the like, desires to utilize theapparatus 200, the housewife sets the timer knob (not shown) of thecontrol system 201 in its selected on position whereby such setting of the control knob of the timer means of theapparatus 200 will close a switch blade 234 against the contact 228 to electrically interconnect a lead 235 to thelead 229, thelead 235 being interconnected to the power source lead L whereby the other side of theelectrical motor 215 will be interconnected to the power source lead I. as long as the switch blade 234 is disposed in its closed position. Thus, if the dryer door is also disposed in its closed position, the power source lead L will be interconnected to theside 226 of theelectrical motor 215 so that theelectrical motor 215 will be energized to not only drive the clothes-receiving drum of thedryer 200, but also to continuously operate thevacuum pump 219 to automatically control thesystem 201 in a manner hereinafter described.

A pneumatically operated valve means 214 is provided for interconnecting a fuel source conduit 213 to a main burner means 212 of theapparatus 200 and comprises a housing means having avalve seat 236 that interconnects the fuel source 213 to the burner means 212, thevalve seat 236 being opened and closed by avalve member 237 that is moved between its open and closed positions by a vacuum operated actuator that is generally indicated by thereference numeral 238 and comprises a cup-shapedhousing member 239 having its open end closed by aflexible diaphragm 240 that is interconnected to thevalve member 237 by a tying means 241 in a conventional manner whereby theflexible diaphragm 240 cooperates with the housing E39 to define achamber 242 position to the force of thecompression spring 243 to move thevalve member 237 to its open position so that the fuel source 213 will be interconnected to the main burner means 212 as long as the pneumatically operatedactuator 238 is in its actuated condition.

The ignition means for the main burner means 212 comprises anignition coil 244 having oneside 245 thereof interconnected by a lead 246 to thelead 235 so that theside 245 of "theignition coil 244 is always interconnected to the power source lead L The other side 2470f theignition coil 244 is interconnected by a lead 248 to aswitch blade 249 that is adapted to close against acontact 250 that is electrically interconnected to the power source lead L by a lead 251 only when a vacuum operatedactuator 242 is actuated.

in particular, the vacuum operatedactuator 252 comprises a cup-shapedhousing 253 having its open end closed by aflexiible diaphragm 254 interconnected to theswitch blade 249 by a tying means 255, thediaphragm 254 cooperating with the housing means 252 to define achamber 256 therebetween which receives acompression spring 257 that normally urges theflexible diaphragm 254 upwardly to the position illustrated inFlG. l to open theswitch blade 249 from thecontact 250.

However, when thechamber 256 is evacuated by being interconnected to thevacuum source 219 in the manner hereinafter described, the pressure differential acting across thediaphragm 254 moves thediaphragm 254 downwardly in opposition to the force of thecompression spring 257 to close theswitch blade 249 against thecontact 250 which, in effect, places theignition coil 244 across the power source leads L and L to energize the same whereby the energized coil 244 'can heat up to a temperature that will be sufficient for igniting fuel issuing from the burner means 212 in a conventional igniting manner.

An ignition coil temperature sensing means 258 is provided for thesystem 201 and comprises abimetal member 259 that is interconnected to avalve member 260 by a tying means 261, thevalve member 260 being disposed in a housing means 262 having avalve seat 263 interconnecting aninlet conduit 264 to anoutlet conduit 265. When thebimetal member 259 senses a temperature of theignition coil 244 below a temperature sufficient for igniting fuel issuing from the main burner means 212, thebimetal member 259 is in such a condition that the same maintains thevalve member 260 away from thevalve seat 263 to fluidly interconnect theconduits 264 and 265 together. However, when theignition coil 244 reaches an ignition temperature, thebimetal member 259 warps in such a manner that the same moves thevalve member 260 against thevalve seat 263 to terminate the fluid connection between theconduits 264 and 265. in addition, when the main burner means 212 is operating, thebimetal member 259 also senses the flames at the main burner means 212 so that the same will maintain thevalve member 260 in its closed position against thevalve seat 263 as long as fuel is burning at the main burner means 212.

Anothertemperature sensing device 266 is provided for thecontrol system 201 and is adapted to sense the temperature effect of the main burner means 212. The temperature sensing means 266 comprises abimetal member 267 that is interconnected to avalve member 268 by a tying means 269, thevalve member 268 being disposed in a housing means 270 to open and close avalve seat 271 thereof that fluidly interconnects theconduit 221 to aconduit 272 that is fluidly interconnected to, theconduit 264 of the ignition temperature sensing means 259.

As long as the temperature effect of the burner means 212 of theapparatus 200 is below a predetermined temperature setting of the sensing means 266, thebimetal member 267 maintains thevalve member 268 away from thevalve seat 271 to fluidly interconnect theconduits 221 and 272 together whereby if theelectrical motor 215 is energized, thevacuum source 218 will be interconnected to theconduit 272. However, when the temperature sensing means 266 senses a temperature effect of the burner means 212 above the set temperature setting of the thermostatic means 266, thebimetal member 267 warps in a manner to move thevalve member 268 against thevalve seat 271 and, thus, disconnect thevacuum source 219 from theconduit 272 for a purpose hereinafter described. Of course, it is to be understood that thesensing device 266 could be manually adjustable for temperature selection purposes by the housewife or the like or could be factory set for an optimum drying temperature.

Theconduit 272 is interconnected to the port means 68 of thelogic unit 40 that performs a MEMORY logic function later to be described, theconduit 272 also being fluidly interconnected to aconduit 275 that leads to the port means 77 of anotherlogic unit 40A that performs a NOT logic function.

Theconduit 265 leading from the ignition temperature sensing means 258 is interconnected to a one-way check valve 279 that leads to the port means 65 of thelogic unit 40.

Theconduit 265 is fluidly interconnected to a conduit means 288 that is fluidly interconnected to thechamber 256 of the vacuum operatedactuator 252, the conduit 288 also being interconnected to aconduit 289 that leads to the atmosphere by means of a restrictor 290 disposed in the conduit means 289.

The fifth port means 71 of the pneumatically operatedlogic MEMORY unit 40 is interconnected by a conduit means 303 to a port means 65 of a'pneumatically operated logic ANDunit 40B of this invention, the logic ANDunit 40B having the fifth port means 71 thereof interconnected by a conduit means 307 to the fifth port means 71 of thelogic NOT unit 40A. The port means 68 of the logic AND unit 4013 is interconnected by a conduit means 310 to thechamber 242 of the pneumatically operatedactuator 238. The port means 77 of thelogicAND unit 40B is interconnected by a conduit means 312 to the atmosphere throughrestrictor 313.

Theconduit 265 that leads from the ignition temperature sensing means 258 is fluidly interconnected to a conduit means 314 that leads to the port means 65 of thelogic NOT unit 40A. The port means 68 of thelogic NOT unit 40A is interconnected to a conduit means 317 that leads to the atmosphere through arestrictor 318.

Thecontrol system 201 is so constructed and arranged that theignition coil 244 for the burner means 212 must be first energized to a temperature thereof that will be sufficient for igniting fuel issuing from the burner means 212 each time before theactuator 238 will move thevalve member 237 from its closed position to its open position to cause fuel to issue from the main burner means 212.

Thus, since bothtemperature sensing devices 258 and 266 are disposed in their open position when the control system 10 is initially turned on by the closing of the switch blade 234 against the contact 228, either manually or automatically by a timer clock or the like, the energizedelectric motor 215 will operate thevacuum pump 219 and since the temperature effect of theapparatus 200 is below the temperature effect settingof thethermostatic device 266, thevacuum pump 219 is adapted to evacuateconduit 272 through the open valve means 268 as well as to evacuateconduits 272 and 314 leading respectively to thelogic MEMORY unit 40 andlogic NOT unit 40A.

As illustrated in FIG. 20, the logic ANDunit 40B will require two vacuum signals from thelogic MEMORY unit 40 andlogic NOT unit 40A respectively through conduit means 303 and 307 to cause the logic AND unit 408 to direct an output vacuum signal through the conduit means 310 to open the valve means 237 so that the fuel source 213 can be interconnected to the main burner means 212. However, the

MEMORY unit 40 must first receive a signal from the conduit means 265 that is caused by the ignition temperature sensing means 258 having itsvalve member 260 disposed in its open condition before theMEMORY unit 40 will direct its output vacuum signal to the AND unit 408. Thelogic NOT unit 40A also receives the vacuum signal from the open setting of thevalve member 260 of the temperature sensing means 258 through the conduit means 314 and will not direct its vacuum output signal through the conduit means 307 to the ANDunit 40A, to cause opening of the valve means 237 for the main burner means 212 until after the signal throughconduit 314 is terminated by the closing of thevalve member 260 against thevalve seat 263 of the ignition temperature sensing means 258 so that the AND unit 403 cannot cause opening of the valve means 237 until after theignition coil 244 has been raised to a temperature proper for ignition of fuel issuing from the burner means 212. Accordingly, thelogic units 40, 40A, and 40B require that thevalve member 260 must be first in an open position and then be moved to a closed position after each closing of themain valve member 237 before themain valve member 237 can be again opened, thevalve member 260 only closing after an open condition thereof when theignition coil 244 is at a temperature suitable for igniting fuel that will be issued from the main burner means 212.

A controlled bleed to the atmosphere for thelogic units 40, 40A, and 40B can be provided in theconduit 272 or in theconduit 310 to reset the same to the position illustrated in FIG. 19 when thevalve member 268 closes against thevalve seat 263 as will be apparent hereinafter. However, in the embodiment illustrated in the drawings, theconduit 310 is interconnected to the atmosphere at a controlled rate by aconduit 342 having a restrictor 343 therein.

Theconduit 303 is interconnected by aconduit 281 toconduit 265 intermediate thecheck valve 279 and theport 65 of theunit 40, the conduit 28] having a restrictor 281 therein.

The operation of thecontrol system 201 of this invention will now be described.

Assuming that the dryer door is in its closed position to hold the switch blade 222 against the contact 224, the housewife or the like sets the selector timer knob for operating thedryer 200 for a predetermined length of time whereby the timer mechanism closes and holds the switch blade 234 against the contact 228 and will maintain the switch blade 234 against the contact 228 during the entire cycle of operation of thedryer 200 at the conclusion of which the timer means will automatically open the blade 234 away from the contact 228 to terminate the operation of theapparatus 200.

With the switch blade 234 now moved to its closed position against the contact 228, it can be seen that theelectric motor 215 is placed across the power source leads L and L so that theelectric motor 215 will continuously rotate the laundry receiving drum to tumble the clothes in an atmosphere to be heated by the burner means 212 for a drying of the laundry or the like. As theoutput shaft 217 of the motor means 215 is continuously rotating, the same through theeccentric cam 216 reciprocate: suitable pumping mechanism of thevacuum pump 219 to continuously provide a vacuum source for thecontrol system 201.

At the initial operation of thecontrol system 201, not only is theignition coil 244 not at an ignition temperature, but also the temperature effect of theapparatus 200 is below the temperature setting for the thermostatic means 266 whereby bothvalve members 260 and 268 are disposed in their open position as illustrated in H0. 19 so that thevacuum source 219 will not only be directed to the vacuum operatedactuator 252 to evacuate thechamber 256 thereof and close theswitch blade 249 against thecontact 250 to place theignition coil 244 across the power source leads L and L but also thevacuum source 219 is interconnected to thevalve seat 67 of theMEMORY unit 40, to thevalve seat 76 of theNOT unit 40A, tochamber 49 of theMEMORY unit 40 through the one way check valve means 279 and to thechamber 49 of theNOT unit 40A. g

Since the vacuum source is interconnected to thechamber 49 of theNOT unit 40A, the. pressure differential created across theintermediate diaphragm portion 84 thereof causes thediaphragm member 46 to move downwardly in opposition to the force of thecompression spring 95 so thediaphragm member 46 closes off thevalve seat 76 and opens thevalve seat 67 to interconnect the atmosphere fromconduit 317 into thechamber 47 thereof and, thus, tochamber 47 of the AND unit 408.

With thevacuum source 219 now being interconnected tochamber 49 of theMEMORY unit 40, the resulting pressure differential across theintermediate diaphragm portion 84 thereof causes thediaphragm member 46 to move upwardly in opposition to the force of thecompression spring 95 to open thevalve seat 67 and close thevalve seat 76 and thereby interconnect the vacuum source to thechamber 47 of theMEMORY unit 40 and, thus, by means of theconduit 303, to thechamber 49 of the AND unit 403. With thevacuum source 219 not interconnected tochamber 49 of the AND unit, 403, the resulting pressure differential across thediaphragm portion 84 thereof moves thediaphragm member 46 of the ANDunit 40B downwardly in opposition to the force of thecompression spring 95 so that thediaphragm member 46 closes thevalve seat 76 leading to the atmosphere through the conduit means 312 while opening thevalve seat 67. However, since thechamber 47 of the AND unit 4013 is now interconnected by theconduit 307 to thechamber 47 of theNOT unit 40A, and sincechamber 47 of theNOT unit 40A is interconnected to the atmosphere by theopen valve seat 67 thereof, thechamber 242 of theactuator 238 remains interconnected to the atmosphere so that thevalve member 237 remains in its closed position against thevalve seat 236 to prevent any flow of fuel from the manifold 213 to the main burner means 212.

When thediaphragm member 46 of theMEMORY unit 40 is moved upwardly in FIG. 19 by the vacuum source being interconnected to thechamber 49 thereof, the vacuum being created inchamber 47 by the openedvalve seat 67 causes evacuation of the conduit means 281 andrestrictor 281 so as to provide a vacuum holding circuit to thechamber 49 for maintaining thediaphragm member 46 of theMEMORY unit 40 in its up position even during the subsequent absence of a vacuum signal in theconduit 265 which will permit thecheck valve 279 to close.

In particular, it can be seen that initially when thediaphragm member 46 of theMEMORY unit 40 is moved to its up position, thediaphragm member 46 of theNOT unit 40A is moved to its down position and thediaphragm member 46 of the AND unit 408 is moved to its down position whereby the atmosphere in thechamber 47 of theNOT unit 40A is effectively interconnected to thechamber 242 of theactuator 238 so that themain valve member 237 remains closed against thevalve seat 236.

Under the above described condition, theignition coil 244 is being energized and when the same reaches a predetermined temperature that is sufficient for ignition purposes, the ignition temperature sensing means 258 causes thevalve member 260 to move to its closed position against thevalve seat 263 to disconnect thevacuum source 219 from the conduit means 265 and 315 while 314 while interconnecting the atmosphere to the same by means of the restrictor 290 in the conduit means 289 so that the conduit means 265 and 314 will be bled to atmospheric pressure.

However, thecheck valve 279 now closes to prevent the bleed of air into the portion of theconduit 265 that leads to thechamber 49 of theMEMORY unit 40 so that thediaphragm member 46 thereof remains in its up position to still interconnect thevacuum source conduit 272 to thechamber 47 thereof and, thus, to thechamber 49 of the ANDunit 40B to maintain thediaphragm member 46 thereof at itsl 242 of theactuator 238.

' The bleed of air into the conduit means 314 begins to bleed air into thechamber 49 of theNOT unit 40A so that when the bleed of air into thechamber 49 sufficiently reduces the pressure differential across theintermediate diaphragm portion 84 thereof, thecompression spring 95 moves thediaphragm member 46 back to the back position illustrated in FIG. 19. In this manner, the vacuum source in theconduit 272 is now interconnected to thechamber 50 through the openedvalve seat 76 and, thus, is interconnected to thechamber 47 of theNOT unit 40A by the passage means 94 in the diaphragm open position whereby fuel is now adapted to flow from the soiirce 213 to the burner means 212 and be ignited by theignition coil 244.

As previously stated, when thevalve member 260 of the ignition temperature sensing means 258 was moved to its closed position against thevalve seat 263, thevacuum source 219 is disconnected from theconduit 265 and, thus, from thechamber 256 of theactuator 252 so that the bleed of air into the conduit 288 from the restrictor 290 permits thechamber 256 in theactuator 252 to return to atmospheric condition and open theswitch blade 249 to terminate the source of current to thecoil 244. However, since thecoil 244 is still at a temperature sufficient to ignite fuel issuing from the burner means 212, the now opened valve means 214 issues fuel from the burner means 212 which is ignited by theheated ignition coil 244. If the fuel from the burner means 212 is properly ignited by theignition coil 244, the temperature sensing means 259 of thesensing device 258 maintains thevalve member 260 against thevalve seat 263 during the burning of fuel at the main burner means 212 whereby the main burner beams 212 continues to burn until the temperature effect thereof reaches the temperature effect being sensed by the sensing means 266.

this time, thebimetal member 267 moves thevalve member 268 against thevalve seat 271 to disconnect thevacuum source 219 from the conduit means 272 and 275 to cause closing of thevalve member 237 in a manner now to be described.

-With thevacuum source 219 now disconnected fromconduit 272 by the closing of thevalve member 268 against the -valve seat 271, the system bleeds down by air passing through therestrictor 343 and intoconduit 342 and, thus, intoconduit 310 to deactuate theactuator 238 to close thevalve member 237 against thevalve seat 236 and thereby terminate the flow of fuel to the main burner means 212. This bleed of air into theconduit 310 also bleeds intochamber 47 of the ANDunit 40B and byconduit 307 intochamber 47,passage 94 andchamber 50 of theNOT unit 40A so as to pass through the openedvalve seat 76 and intoconduits 275 and 272 that lead to the chamber'47 ofMEMORY unit 40.Chamber 47 ofunit 40 now' bleeds air intochamber 49 thereof by the passage means 281 to return theMEMORY unit 40 to the condition illustrated in FIG. 19. Similarly, with atmosphere now in thechamber 47 of theMEMORY unit 40, atmosphere is directed tochamber 49 of the AND unit 408 to cause the same to return to the condition illustrated in FIG. 19 whereby theentire control system 201 isturned off except that theelectric motor 215 is continuing to operate to tumble the laundry in the heated atmosphere of thedryer 200.

The temperature effect in thedryer 200 now begins to drop because of the terminated operation of the main burner means 212. When the dropping temperature effect falls below the predetermined temperature setting of thethermostatic device 266, thebimetal member 267 again moves thevalve member 268 to its open position to interconnect theconduit 221 to theconduit 272. When the flames ceased to exist at the main burner means 212 when the same was turned off by the closing of thevalve member 237 in the manner previously described, thebimetal member 259 moved thevalve member 260 to its open position as illustrated in FIG. 19 whereby the previously described cycle of operation for energizing theignition coil 244 and the subsequent opening of thevalve member 237 is repeated in the manner previously described to again cause operation in the main burner means 212.

Thus, it can be seen that thesystem 201 of this invention can cycle the main burner means 212 on and off in the manner previously described to tend to maintain the temperature effect in thedryer 200 at the temperature effect setting of thethermostatic device 266 until the timer opens the switch blade 234 to deenergize themotor 215 and, thus, turn off thevacuum source 219 whereby the entire system will bleed down through the restrictor means in the manner previously described so that the valve means 237 will be maintained in its closed position and the switch blade 234 will be disposed in its open position. v p

If during the normal cycle of operation of thecontrol system 201 in the manner previously described, the housewife or the like should open and then close the access door for any:

reason, such opening of the door will open switch blade 222 to stop theelectric motor 215 and, thus, terminate thevacuum source 219 so that thesystem 201 will bleed down to the off condition of FIG. 19. However, the housewife after opening such access door may quickly shut the same to again energize theelectric motor 215. When access door is thus momentarily opened, thevacuum source 219 is terminated permitting the entire pneumatic control system to bleed down to atmospheric conditions by means of the restrictors in the manner previously described so that the previously created vacuum in thechamber 49 of theMEMORY unit 40 will cease to exist and thediaphragm member 46 will be moved downwardly to the position illustrated in FIG. 19 by the force of the compression spring so as to prevent the occurrence of a MEMORY unit output vacuum signal in thechamber 47 thereof until a vacuum signal is again created in theconduit 265 in the manner previously described. The closing of the access door restarts themain motor 215 and restores thevacuum source 219. However, due to the construction and location of thebimetal member 259 of theflame sensing device 258, thebimetal member 259 is still warm because of a thermal lag therein and acts as if a main burner flame at the burner means 212 is still present so that thevalve member 260 remains against thevalve seat 263 during the intermittent opening and closing of the access door during the normal cycle of operation of theapparatus 200. Accordingly, the main thermostatic means 266 is now sensing a temperature effect in theapparatus 200 below the predetermined temperature effect so that thevalve member 268 thereof is movedto an open position as illustrated in FIG. 19 to interconnect thevacuum source 219 to the conduit means 272 and 275 leading to theMEMORY unit 40 andNOT unit 40A.

However, theMEMORY unit 40 of this invention cannot move from the position illustrated in FIG. 19 to its up position to interconnect the vacuum now in theconduit 272 to thechamber 47 thereof and, thus, to move thediaphragm member 46 of the ANDunit 40B downwardly from the position illustrated in FIG. 19 until a vacuumsignal is directed to thechamber 47 thereof by the subsequent opening of thevalve member 260 of the flame sensing means 258.

Thus, before thevalve member 260 of the flame sensing means 258 opens, the vacuum being created inchamber 50 and, thus, inchamber 47 of theNOT unit 40A, although being directed to thechamber 47 of the AND unit 4018, cannot be directed to theactuator 238 to open themain valve member 237 because theMEMORY unit 40 is not directing a vacuum signal through theconduit 303 tochamber 49 of the AND unit 408 so that thecompression spring 95 of the ANDunit 40B holds thediaphragm member 46 thereof against thevalve seat 67 to prevent any vacuum to be supplied to thechamber 242 of theactuator 238.

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