US3378933A - Drying system for dishwasher - Google Patents

Description

P 1968 T. E JENKINS I 3,378,933

DRYING SYSTEM FOR DISHWASHER Filed Jan. 13, 1966 5 Sheets-Sheet l l3 1] l1 I1 n In I'll l'l \III II II II II Ii\ LL11 n u n II n l4- .1 n a m W 1:13 i INVENTOR.

THOMAS E J'ENK\NS Isa 3W (56% ms ATTORNEY April 23, 1968 "r. E. JENKINS 3,378,933

DRYING SYSTEM FOR DISHWASHER Filed Jan. 13, 1966 3 Sheets-Sheet 24Q ea 42 37 '45 3 J r 74G 43 35/f 43 4 INVENTOR.

THOMAS E. IENKHUS Flea F16. 4 BY 6T zz ATTORNEY April 1968 T. E. JE NKINS 3,378,933

DRYING SYSTEM FOR DISHWASHER Filed Jan. 1;, 1966 3 Sheets-Sheet 5 INVENTOR. THOMAS E. JENKINS H \5 ATTORNEY United States Patent 3,378,933 DRYING SYSTEM FOR DISHWASHER Thomas E. Jenkins, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Jan. 13, 1966, Ser. No. 520,442 9 Claims. (Cl. 3454) ABSTRACT OF THE DISCLOSURE An electrically heated drying system for a dishwasher including ablower and means interconnecting the blower to the dishwasher wash chamber. An electrical heating element is disposed within the path of air propelled by the blower and electrically-responsive valve means is provided to control the How of air through the blower. The electrically-responsive valve means is connected in electrical series with another electrical component of the dishwasher to be controlled by the same control means which controls the other electrical component.

This invention relates to a drying system for an automatic dishwasher and, more particularly, to a system which provides automatic operation integrated with a complete dishwasher cycle of operation.

A normal cycle of operation for an automatic dishwasher includes a preliminary rinse or two, a wash which includes the addition of detergent to the water, a subsequent rinse or two, and finally, a drying period during which the air Within the dishwasher is heated to enhance evaporation of moisture from the washed articles. Often, the wash chamber of the dishwasher is vented during drying so that moisture laden air may escape and be replaced by dry air to further enhance evaporation of moisture from the article. Although convective movement of air through the wash chamber is achieved by heating the air and venting the wash chamber, it has been discovered that mechanical movement of the air, by means of a blower, further enhances drying of the articles. However, use of a blower has been generally rejected due to the complication and expense of incorporating a blower into the dishwasher, both mechanically and electrically. The present invention provides a simple inexpensive means to incorporate a blower into a dishwasher for use during the drying period of the dishwasher cycle of operation.

It is an object of this invention to provide an improved drying system for a dishwasher.

It is a further object of this invention to provide a drying system for a dishwasher which is inexpensive and uncomplicated.

Briefly stated, in accordance with one aspect of the invention, there is provided a heating system for a dishwasher including a blower and means interconnecting the blower with the wash chamber of the dishwasher. An electrical heating element is disposed within the path of air propelled by the blower and an electrically-responsive means is provided to control the flow of air through the blower. The electrically-responsive means is in electrical series circuit with another electrical component of the dishwasher to be controlled by the same control means which controls the other electrical component.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is an elevational view, partly cut away to show details, of a dishwasher employing the present invention;

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FIGURE 2 is a schematic wiring diagram showing the control circuit of the dishwasher of FIGURE 1;

FIGURE 3 is a fragmentary view of a component of the present invention;

FIGURE 4 is a view similar to FIGURE 3, but showing the component in a second operative position;

FIGURE 5 is a schematic wiring diagram showing a modified control circuit for a dishwasher such as that illustrated in FIGURE 1; and,

FIGURE 6 is a fragmentary view of a modified component of the present invention.

Referring now to the drawings, and more particularly to FIGURE 1 thereof, there is illustrated anautomatic dishwasher 10 having an outer cabinet 11 defining therein awash chamber 12. Disposed withinwash chamber 12 aredish supporting racks 13 and 14 which are adapted to receive and support dishes or other articles to be washed withinwash chamber 12. Aclosure member 15 is provided in one wall of cabinet 11, pivotal about hinge means 16, to provide access towash chamber 12. Whenclosure member 15 is pivoted downwardly,rack 13 can be at least partially withdrawn fromwash chamber 12 by means of a slide androller system 17 provided at each side ofrack 13 and slidably supportingrack 13 from the inner wall of cabinet 11. Similarly,rack 14 can be at least partially withdrawn fromwash chamber 12 by means of aroller 18 which rides upon asurface 19 provided at each side of cabinet 11.

The lower extremity ofwash chamber 12 is defined by a bottom wall 20 which gradually slopes to a low point at one side of the dishwasher. Disposed below the low point is asump 22 which may be formed integrally with bottom wall 20 or which may be a separate element secured to bottom wall 20. Projecting upwardly from bottom wall 20 near the center ofwash chamber 12 is apedestal 23 which rotatably supports a reactiontype spray device 24.Spray device 24 has a plurality oforifices 25 through which wash fluid is ejected to effectuate a washing action upon articles supported byracks 13 and 14. At least one of theorifices 25 is directed such that the reaction force created by the wash fluid passingtherethrough causes rotation ofspray device 24.

Wash fluid is propelled intospray device 24 by amotorpump assembly 26 including anelectric motor 27 and apump 28. A flexible boot orconduit 29interconnects sump 22 with the inlet ofpump 28.Boot 29 is secured tosump 22 by means of a clamp 30 and is secured to pump 28 similarly by means of aclamp 31. Motor-pump assembly 26 is suitably supported from bottom Wall 20.

An electrically-operated solenoid (not shown in FIG- URE 1) operates a valve (not shown) within the housing ofpump 28 to selectively direct the fluid pumped bypump 28 either up throughspray device 24 or out through aneflluent discharge conduit 33.

During the drying period of the dishwasher operational cycle, the air withinwash chamber 12 is heated to enhance the evaporation of moisture from articles supported byracks 13 and 14. To carry out this heating, ablower 34 is supported beneath bottom wall 20 and includes ahousing 35 which contains animpeller 36 therein.Impeller 36 is mechanically linked tomotor 27 to be driven thereby.Housing 35 has aninlet 37 and anoutlet 38. Aconduit 39interconnects outlet 38 withwash chamber 12. Apivotal cover 40 is provided at the upper end ofconduit 39 to prevent wash fluid from enteringconduit 39 during the wash and rinse periods of the dishwasher cycle of operation. An electricalresistance heating element 41 is provided inconduit 39 to heat the air passing through that conduit whenheating element 41 is energized.

A clearer understanding of the operational cycle ofdishwasher 10 can be obtained by reference to FIGURE 2 of the drawings. FIGURE 2 provides an end view ofblower 34 and shows avalve 42 disposed overinlet 37. Valve 42 obviously controls the flow of air throughblower 34 andvalve 42 is provided with an electricallyresponsive valve operator 43. Valveoperator 43 includes asupport 44 rigidly secured to housing and a plurality ofbimetallic elements 45, each of which are secured at one end to support 44 and, at the other end, to abracket 46. Bracket 46 is rigidly secured tovalve 42. The individual bimetallic elements are connected in electrical series circuit with each other so that current flowing intoelements 45 throughterminal 47 will pass, in series, through all ofelements 45 toterminal 48.

FIGURE 3 is a view taken alongline 33 of FIGURE 2 and showsvalve 42 seated againsthousing 35 to closeinlet 37. When electrical current is passed throughelements 45,valve operator 43 assumes the position shown in FIGURE 4 which withdrawsvalve 42 fromhousing 35 thereby openinginlet 37 and allowing the flow of air throughblower 34 intowash chamber 12.

Referring again to FIGURE 2, power is supplied to the dishwasher control means through lines L and L A sequence control means 49 includes a synchronous timer motor 50 which mechanically drives a plurality ofcams 51, 51a, 52, 53 and 54 which operate, respectively,switches 55, 55a, 56, 57 and 58. Switch 55 controls the admission of electrical power to timer motor 50 and is initially closed by manual rotation of a control knob mechanically linked to timer motor 50. When the control knob is turned two or three degrees, cam 51 closesswich 55 which energizes timer motor 50 and timer motor 50, from that moment on, continues to drive the cams throughout an entire dishwasher cycle. Upon completion of the terminal portion of the dishwasher cycle of operation,cam 51 reopensswitch 55 thereby deenergizing motor 50. At this point, the remainingswitches 55a 56, 57 and 58 have been opened bycams 51a, 52, 53 and 54 so that the entire dishwasher is deenergized.

A normal complete dishwasher cycle of operation may include the following sequence of events. Initially, electrically-operatedvalve 59 is opened by the closing ofswitch 56 to allow the admission of water intowash chamber 12. When a suitable amount of water has been allowed to enterwash chamber 12,cam 52 opens switch 56 thereby closingvalve 59. At the time that switch 56 is closedcam 53 closes switch 57 thereby energizingmotor 27. Cam 51:: allows switch 55a to remain open, thereby maintainingsolenoid 60 deenergized so that the valve which controls flow of fluid either up throughspray device 24 or out throughefliuent discharge conduit 33 is in a position whereby fluid is directed up throughspray device 24. This condition obtains for several minutes until cam 51a closes switch 55a to energizesolenoid 60 thereby causing the valve withinpump 28 to direct the wash fluid out throughefliuent discharge conduit 33. After the passage of a time interval sufliciently long to remove substantially all of the fluid from the dishwasher, cam 51a reopens switch55a deenergizing solenoid 60. At this time,cam 52 closes switch 56 thereby energizing andopening valve 59 so that water is again admitted to washchamber 12.

The foregoing series of events is repeated several times and, during at least one of the times, a detergent dispenser (not shown) is operated to inject or dispense detergent intowash chamber 12 to mix with the water to facilitate removal of food soil from the articles disposed inwash chamber 12. Following the final rinse,motor 27 remains energized, andcam 54 closes switch 58 thereby allowing current to flow throughheating element 41 andvalve operator 43. As this happens, air is drawn in throughinlet 37 ofhousing 35 and is propelled up throughconduit 39,past heating element 41 to be blown intowash chamber 12. -It is to be understood that the air propelled byblower 34 exerts a sufficient force uponcover 40 to open it to the position shown in dotted lines in FIGURE 1.

By placing thevalve operator 43 in electrical series circuit withheating element 41, thevalve 42 is automatically opened wheneverheating element 41 is energized and remains closed at all other times. Also, by placing theheating element 41 andvalve operator 43 in series, the voltage drop realized acrossheating element 41 results in a significant lower voltage impressed across thebimetallic elements 45. As described above,motor 27 remains energized throughout the entire dishwasher cycle which proves advantageous if, for example,motor 27 is of the shaded-pole type having a relatively low starting torque. Ifmotor 27 is of the type having a low starting torque, it it advantageous to avoid the situation whereinmotor 27 must start under load and one way to avoid this situation is to start the motor prior to applying the load. This is done in the present invention by startingmotor 27 before water is admitted to washchamber 12 andpump 28. Becausemotor 27 is to be energized throughout the entire dishwasher cycle, andblower 34 is useful only during the drying portion of the cycle, the present invention obviates a relatively expensive clutch mechanism betweenmotor 27 andblower 34 which otherwise would be required in order to prevent air from being blown intowash chamber 12. If air were allowed to blow intowash chamber 12, it could result in impairment of the wash action of the fluid emanating fromorifices 25. Morover, air blowing intowash chamber 12 would maintaincover 40 in the open position which would allow wash fluid to enterconduit 39 and collect in casing 35 ofblower 34. Closing theinlet 37 toblower 34 also decreases the power necessary to rotateimpeller 36 during the periods when movement of air is not necessary.

Referring now to FIGURE 5, a modification of the electrical relationship of the components of FIGURE 2 is shown. A sequence control means 61 is provided and includes a synchronous timer motor 62 andcams 63, 64, 65, 66, 67 and 68 which control, respectively, switches 69, 70, 71, 72, 73 and 74. The operation of the elements comprising the control system of FIGURE 5 are identical to that of the elements comprising the control system of FIGURE 2 with the following exceptions.Cam 67 closes switch 73 at the initial portion of the dishwasher cycle of operation and maintains switch 73 closed throughout the cycle until the drying period is reached whereupon switch 73 is opened bycam 67 and switch 74 is closed by cam 68. Thus, during the drying period,motor 27 is energized through switch 74, but switch 74 is also in electrical series circuit withvalve operator 43 so thatvalve 42 opensinlet 37 during the drying period.

The arrangement shown in FIGURE 5 requires an additional cam and switch and is therefore less preferred than the arrangement of FIGURE 2; however, the arrangement of FIGURE 5 does utilize the voltage drop acrossmotor 27 to decrease the voltage impressed acrossbimetallic elements 45 in a manner similar to that achieved by the voltage drop ofheating element 41 in the arrangement of FIGURE 2.

FIGURE 6 illustrates a modified valve and valve operator for controlling the admission of air intoblower 34. Avalve 75 is pivotally attached tohousing 35 by means of apin 76. Avalve operator 77 is provided and includes asupport 78 rigidly secured tohousing 35 by means of bolts or screws 79. Abimetallic element 80 is rigidly supported at one end bysupport 78 and is secured at its other end to anarm 81.Arm 81 has aslot 82 at its distal end which receives apin 83 projecting fromvalve 75.Bimetallic element 80 has a pair ofelectrical terminals 84 and 85 which may be incorporated into an electrical control circuit in a manner identical to that ofterminals 47 and 48 of the earlier described embodiments. When electrical current is caused to pass throughbimetallic element 80,element 80 assumes the position shown in dotted lines in FIGURE 6 thereby pivotingvalve 75 aboutpin 76 to the position also shown in dotted lines in FIGURE 6. The arrangement shown in FIGURE 6, although somewhat more complex and more expensive than the arrange- 5 ment illustrated in FIGURES 2 and 5, may prove advantageous insome applications since it avoids the requirement of directly overcoming the vacuum created atinlet 37 byimpeller 36. Because it overcomes this requirement, it is possible to use a smaller number of bimetallic elements to effectuate movement ofvalve 75.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of construction of the examples illustrated, and it is contemplated that various other modifications or applications will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

11. A drying system for a dishwasher comprising:

(a) an electric motor,

(b) a blower driven by said motor,

(c) a conduit interconnecting said blower with the wash chamber of the dishwasher,

(d) an electrical heating element within said conduit,

(e) an inlet to said blower,

(f) a valve to control flow through said inlet, and

(g) an electrically-responsive valve operator to open and close said valve,

(h) said valve operator being in electrical series circuit with said heating element whereby said valve is opened when said heating element is energized.

2. The invention of claim 1 wherein said electricallyresponsive valve operator comprises a bimetal element and said bimetal element solely supports said valve.

3. A drying system for a dishwasher comprising:

(a) a blower,

(b) means interconnecting said blower with the wash chamber of the dishwasher,

(c) an electrical heating element disposed within the path of air emanating from said blower, and

(d) electrically-responsive valve means to control the flow of air through said blower,

(e) said electrically-responsive means being in electrical series circuit with said heating element whereby said means allows air to flow through said blower when said heating element is energized.

4. The invention of claim 3 further comprising a housing for said blower and an inlet for said housing, wherein said electrically-responsive means comprises a valve pivotally carried by said housing and a bimetal valve operator to pivot said valve relative to said inlet to open and close said inlet.

5. The invention of claim 3 wherein said electricallyresponsive means comprises a bimetal operator and a valve member supported solely by said bimetal operator.

6. The invention of claim 5 further comprising a housing for said blower defining an inlet wherein said valve cooperates with said inlet to control the flow of air.

7. A drying system for a dishwasher comprising:

(a) an electric motor,

(b) a blower driven by said motor,

(c) a housing for said blower having an inlet for said blower,

(d) a valve to selectively open and close said inlet,

(e) an electrically-responsive operator to operate said valve,

(f) said electrically-responsive operator being in electrical series circuit with said motor,

(g) first switch means in electrical series circuit with both said motor and said operator, and

(h) second switch means in electrical series circuit with said motor and in parallel electrical series circuit with said operator.

8. The invention of claim 7 wherein said electricallyresponsive operator comprises a bimetal element solely supporting said valve.

9. The invention of claim 7 wherein said valve is pivotally carried by said housing and said electricallyresponsive operator comprises a bimetal element.

References Cited UNITED STATES PATENTS 2,961,863 11/1960 Sulcek 68-20 3,130,737 4/1964 Jellies 134----57 3,241,563 3/1966 Braden 13457 FREDERICK L. MATTESON, JR., Primary Examiner. J. W. WESTHAVER, Examiner.

A. D. HERRMANN, Assistant Examiner.

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