US3151805A - Vacuum operated pump - Google Patents

Description

Oct. 6, 1964 J. F. PRIBONIC VACUUM OPERATED PUMP Filed June 29, 1961 2 Sheets-Sheet l INV EN 1 OR. JOHN E PRIB ONIC HIS ATTORNEY Oct. 6, 1964 J. F. PRIBONIC 3,151,805

vacuum OPERATED PUMP Filed June 29, 1961 -2 Sheets-Sheet 2 INVENTOR. 4 Jfll/fi f. PR/BON/C ms ATT'OR/YE United States Patent 3,151,895 VAQl 1 UM GPERATED FUR IF John F. Frihonic, Dayton, Gino, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed lune 29, 1961, Ser. No. 126,454 1 Claim. (Cl. 239-52) This invention relates to a vacuum operated pump that is particulmly useful in compressing air for use in air pressure actuated devices.

An object of the invention is to provide a vacuum operated fluid pump, particularly of the diaphragm operated type, wherein the pump is provided with a pa r of opposed and coaxially aligned pistons and cylinders with the cylinders and pistons being valved in a manner that the pump can compress fluids in two stages with the fluid compressed in the first stage be g delivered to the second stage through an axial passage provided in the piston rod that connects the pistons together and also connects the pistons to the diaphragm of the pump.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIGURE 1 is an elevational view of a pump incorporating features of this invention.

FIGURE 2 is a cross sectional view taken along line 2-2 of FIGURE 1.

FIGURE 3 is a partial cross sectional view taken alongline 3--3 of FIGURE 1 to illustrate the valving for operating the pump.

FIGURE 4 is a perspective view of the valve element that controls operation of the pump.

FIGURE 5 is an elevational view of an insert element used in the valve element shown in FIGURE 4.

FIGURE 6 is a cross sectional view taken along line 6- i of FIGURE 7 illustrating a part of the operating mechanism for the control valve of the pump.

FIGURE 7 is a partial elevational view or" the pump similar to FIGURE 1 but with the valve operating mechanism illustrated in a position in which it is ready to move from the position shown in FIGURE 1 to the position shown in FIGURE 9.

FIGURE 8 is a cross sectional view taken along line 8-8 of FIGURE 1 illustrating certain of the valve passages for the pump.

FIGURE 9 is a partial elevational view similar to FIG- URE 1 wherein the valve operating mechanism has been moved to its opposite position.

FIGURE 10 is a cross sectional view taken along line Ill-16 of FIGURE 9.

FIGURE 11 is a cross sectional view taken along line 11-11 of FIGURE 7 illustrating the porting for operating the pump.

In this invention the pump comprises a first housing member it? and a second housing member 11 that cooperate to form a closed chamber that is divided into two compartments l2 and 13 by means of aflexible diaphragm 14 having its periphery secured between the flangedportions 15 and 16 of the respective housing members.

The housing It has afirst cylinder 17 formed as an integral part thereof while the housing ll has asecond cylinder 18 formed as an integral part of the housing 11.

The cylinder bore 19 ofcylinder 17 receives apiston 2% while the cylinder bore 21 ofcylinder 18 receives apiston 22. Thepistons 29 and 22 are connected together by piston rod means 23 that is formed of the twoparts 230 and 23b,part 23a having a threadedend portion 24 received in a mating threaded portion in the part 2317. The threadedportion 24 extends through a central opening in the diaphragm l4 and a pair of diaphragm clamping plates and 126 are retained on opposite sides of the diaphragm between theparts 23a and 23b of thepiston rod 23.

Thecylinder 17 has afirst valve chamber 25 that also includes afluid inlet port 26 provided in thefitting 27. Theinlet port 26 is closed by afirst valve member 28 retained on its seat on fitting 27 by thecompression spring 29. Thevalve chamber 25 is open to the cylinder bore 19 so that movement of thepiston 24 in a leftward direction, as viewed in FIGURE 2, will draw air in through theinlet port 26.

Thepiston member 2% has a second valve chamber 343 that has afitting member 31 positioned therein by asnap ring 32 and has adischarge port 33 therein through which pressurized fluid is discharged from thecylinder bore 19. Thedischarge port 33 is closed by asecond valve member 34 retained on a seat on thefitting member 31 by means of the compression spring 335. Thevalve chamber 3% is open to theaxial bore 35 provided through the piston rod members 23:; and 23b for delivery of pressurized fluid into thisaxial bore 35 from the cylinder bore 19 when thepiston 2 moves in a righthand direction, as viewed in FIGURE 2.

Thepiston member 22 has athird valve chamber 36 that receives athird valve member 37 seated upon avalve seat 33 formed at the end of theaxial passage 35, thevalve member 37 being retained on the seat by thecompression spring 3?. The valve chamber as is open to the cylinder bore 21 for flow of pressurized fluid from thepassage 35 in the piston rod into the cylinder bore 21 as thepiston 22 moves a righthand direction, as viewed in FIGURE 2.

Thecylinder 18 has a fourth valve chamber 49 hat has afitting member 41 provided with adischarge port 42 from cylinder bore 21 closed by avalve member 43 as held on a seat on themember 41 by thecompression spring 44,valve member 43 allowing fluid under pressur to pass from the cylinder chamber 21 into the conduit passage 4-5 provided in thefitting 46 when thepiston 22 moves in a lefthand direction, as viewed in FIGURE 2.

It will be noted that all fourvalve members 28, 34 3'7 and 43 are positioned on the axis of thecylinders 13 and 17 and coaxial therewith and that all of the valves open in one common direction and close in the opposite common direction so that fluid flow is unidirectional from theinlet 26 to thedischarge conduit 45 in compressing fluid in stages, first in thecylinder bore 19 and thence in the cylinder bore 21 in the reciprocating stroke of thepistons 29 and 22. The arrangement provides for a pump having all of the flow passages contained within the pump so that no exterior conduits will be necessary to conduct pressurized fluid from the firststage compression chamber 19 to the second stage compression chamber 21.

Thepistons 20 and 22 are reciprocated in their respective cylinder bores by means of thediaphragm 14 as it moves from a position shown in FIGURE 2 to a position shown in FIGURE 10, thecompartments 12 and 13 being connected alternately with a vacuum or subatmospheric pressure source while the opposite compartment is connected with atmosphere to obtain thereby a pressure differential at opposite sides of the diaphragm effective alternately to drive thediaphragm 14 in a lefthand direction whenchamber 12 is open to atmosphere andcompartment 13 is connected with a vacuum source and then to drive the diaphragm in a righthand direction to the position shown in FIGURE whencompartment 13 is at atmosphere pressure andcompartment 12 is connected with the vacuum source.

Thehousing member 19 has aport 50 adapted for connection with a source of vacuum or subatmosphere pressure, such as the vacuum manifold on an internal combustion engine of an automotive vehicle. Thehousing 10 is also provided with twoports 51 and 52 positioned equidistantly at each side of thevacuum port 59,port 51 being connected withcompartment 12 andport 52 being connected withcompartment 13 by means of aport extension 53 providing in the housing member 11, as shown in FIGURE 11.

Thehousing member 19 has aplanar face 54 on which avalve member 55 is positioned as pivotally mounted thereon by apivot screw 56, as shown in FIGURE 6. Thevalve member 55 is preferably of a semi-hard rubber material so that it will not produce undesired clicking noise when engaging thestops 57 and 58 in movement alternately from the position shown in FIGURE 1 to that shown in FIGURE 9 in a manner hereinafter described. To reduce the friction of movement of theplanar face 59 of thevalve 55 over theplanar surface 54 of thehousing member 10, aninsert member 6%, more specifically shown in FIGURE 5, is placed in thevalve member 55, the insert being formed of Teflon or other suitable self-lubricating plastic material or nylon. Theinsert member 6%) has a pair ofports 61 and 62 that also provide ports through thevalve member 55, as shown in FIGURE 11. Theseports 61 and 62 are adapted to align alternately with theports 51 and 52 in the housing wall and thereby alternately connect thechambers 12 and 13 with atmosphere.

Theinsert member 60 also has arecessed chamber 65 that communicates with the vacuum orsubatmosphere port 50 in the housing wall and is adapted to alternately connect theport 59 with theport 51 as shown in FIG- URE 11 when thevalve member 55 is in the position shown in FIGURE 1, or to connect theport 50 with theport 52 when thevalve member 55 is in the position as shown in FIGURE 9, and thereby alternately connectchambers 12 and 13 with the vacuum orsubatmosphere port 50. From FIGURE 11 it will be apparent that whenchamber 12 is connected with thesubatmosphere port 50,chamber 13 will be connected with atmosphere, and that when thevalve member 55 shifts to its opposite position, thatchamber 13 will then be connected with the subsatmosphere orvacuum port 50 whilechamber 12 is connected with atmosphere and thereby alternately effect a pressure differential at opposite sides of the diaphragm 14- to alternately move it from the position shown in FIGURE 2 to the position shown in FIGURE 10 and thereby reciprocate thepistons 20 and 22 in theirrespective cylinders 19 and 21.

Thevalve member 55 is shifted alternately from the position shown in FIGURE 1 to the position shown in FIGURE 9 by a mechanism that is actuated by reciprocable movement of thepiston 2%.

As mentioned above, provision of a low coeflicient of friction plastic insert member between theplanar face 59 of thevalve 55 and theplanar surface 54 of thehousing member 10 effectively produces a smaller resultant force resisting the valve shifting mechanism to be more particularly set forth in the following portion of 4 the specification. The overall efficiency of the compressor is thereby improved.

Thepiston 20 has radialannular shoulder portions 70 and 71 that engage afinger member 72 secured on arock shaft 73 pivotally mounted in theextension 74 of the housing member 1% as shown in FIGURE 6. Thus theend portion 75 of therock shaft 73 oscillates from a position shown in FIGURE 1 to a position shown in FIGURE 9 as theshoulder portions 70 and 71 alternately engage thefinger 72 and move it from the position shown in FIGURE 2 to the position shown in FIG-URE 10.

Theend portion 75 of therock shaft 73 extends through alever 76 through aslot 77,lever 76 being pivoted onhousing portion 74 by means of apivot screw 78. Thus thelever 76 is oscillated about thepivot 78 from the position shown in FIGURE 1 to the position shown in FIGURE 9 in accordance with oscillation ofrock shaft 73. V

The free end of thelever 76 has aslot 178 through which apin 79 extends from the secondary lever 8i) that is carried on thepivot screw 56 which also supports thevalve member 55 as shown in FIGURE 6. Oscillation of the lever '76 by therock shaft 73 also occasions oscillation of theintermediate member 80 about thepivot screw 56 from the position shown in FIGURE 1 to the position shown in FIGURE 9. A compression spring extends between theend portion 75 of the rock shaft and thepin 79 mounted on the intermediate member St), so that as thelever 76 moves from the position shown in FIGURE 1 through a position shown in FIG- URE 7, thespring 35 moves over the axis center of thepivot screw 56 resulting in the snap action movement of the intermediate member 86 to engage thevalve 55 and move it rapidly from the position shown in FIG- URE 1 to the position shown in FIGURE 9 and to thereby, reverse the porting of thechambers 12 and 13 in the manner heretofore described.

Theintermediate member 80 is adapted to engage thestop lugs 81 and 82 provide at opposite sides of the Valve 55 when oscillating the valve member between the positions shown in FIGURE 1 and FIGURE 9 as the member 89 is carried alternately back and forth by thelever 76.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

In a pump, in combination, a housing forming a chamher, a flexible diaphragm extending transversely of said chamber for dividing it into first and second compartments, said housing including cylinder means at opposite sides of said diaphragm, piston means in each of said cylinder means, piston rod means connecting each of said piston means and connected to said diaphragm for reciprocation thereby of said piston means in said cylinder means, said piston means and piston rod means having a passageway directed axially therethrough interconnecting said cylinder means, means defining first and second ports in said housing communicating said first and second compartments respectively with atmosphere, means defining a third port in said housing adapted to be connected to a source of subatmospheric pressure, a movable valving element sealingly engaging said housing including means therein for alternately connecting said third port with one of said first and second ports while leaving another of said first and second ports exposed to atmosphere to effect a pressure differential across said diaphragm for reciprocating said piston means, a pair of spaced stop means for limiting the movement of said valving element, valve actuator means operatively associated with said piston means for moving said valving element to effect the alternate intercommunication of said first and second ports with atmosphere and said third port, said valving element and stop means being 5 6 of relatively resiliently yieldable material to damp click- References Cited in the file of this patent ing noises upon operative engagement with one another, UNITED STATES PATENTS said valving element including a portion of low coefficient of friction plastic material supported in sliding 862867 Eggleston Z 1907 2,630,102 Osburn Mar. 3, 1953 sealing engagement with said housing, said valving element portion having passageway means therein for com- FOREIGN PATENTS municating said first and second ports with said third 198,219 Gre t Britai May 31, 1923 port upon movement of said valving element between 744,024 France Apr. 11, 1933 said stop means. 86,538 Norway Sept. 24, 1955

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