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 along line 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 a flexible diaphragm 14 having its periphery secured between the flanged portions 15 and 16 of the respective housing members.

The housing It has a first cylinder 17 formed as an integral part thereof while the housing ll has a second cylinder 18 formed as an integral part of the housing 11.

The cylinder bore 19 of cylinder 17 receives a piston 2% while the cylinder bore 21 of cylinder 18 receives a piston 22. The pistons 29 and 22 are connected together by piston rod means 23 that is formed of the two parts 230 and 23b, part 23a having a threaded end portion 24 received in a mating threaded portion in the part 2317. The threaded portion 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 the parts 23a and 23b of the piston rod 23.

The cylinder 17 has a first valve chamber 25 that also includes a fluid inlet port 26 provided in the fitting 27. The inlet port 26 is closed by a first valve member 28 retained on its seat on fitting 27 by the compression spring 29. The valve chamber 25 is open to the cylinder bore 19 so that movement of the piston 24 in a leftward direction, as viewed in FIGURE 2, will draw air in through the inlet port 26.

The piston member 2% has a second valve chamber 343 that has a fitting member 31 positioned therein by a snap ring 32 and has a discharge port 33 therein through which pressurized fluid is discharged from the cylinder bore 19. The discharge port 33 is closed by a second valve member 34 retained on a seat on the fitting member 31 by means of the compression spring 335. The valve chamber 3% is open to the axial bore 35 provided through the piston rod members 23:; and 23b for delivery of pressurized fluid into this axial bore 35 from the cylinder bore 19 when the piston 2 moves in a righthand direction, as viewed in FIGURE 2.

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

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

It will be noted that all four valve members 28, 34 3'7 and 43 are positioned on the axis of the cylinders 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 the inlet 26 to the discharge conduit 45 in compressing fluid in stages, first in the cylinder bore 19 and thence in the cylinder bore 21 in the reciprocating stroke of the pistons 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 first stage compression chamber 19 to the second stage compression chamber 21.

The pistons 20 and 22 are reciprocated in their respective cylinder bores by means of the diaphragm 14 as it moves from a position shown in FIGURE 2 to a position shown in FIGURE 10, the compartments 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 the diaphragm 14 in a lefthand direction when chamber 12 is open to atmosphere and compartment 13 is connected with a vacuum source and then to drive the diaphragm in a righthand direction to the position shown in FIGURE when compartment 13 is at atmosphere pressure and compartment 12 is connected with the vacuum source.

The housing member 19 has a port 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. The housing 10 is also provided with two ports 51 and 52 positioned equidistantly at each side of the vacuum port 59, port 51 being connected with compartment 12 and port 52 being connected with compartment 13 by means of a port extension 53 providing in the housing member 11, as shown in FIGURE 11.

The housing member 19 has a planar face 54 on which a valve member 55 is positioned as pivotally mounted thereon by a pivot screw 56, as shown in FIGURE 6. The valve member 55 is preferably of a semi-hard rubber material so that it will not produce undesired clicking noise when engaging the stops 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 the planar face 59 of the valve 55 over the planar surface 54 of the housing member 10, an insert member 6%, more specifically shown in FIGURE 5, is placed in the valve member 55, the insert being formed of Teflon or other suitable self-lubricating plastic material or nylon. The insert member 6%) has a pair of ports 61 and 62 that also provide ports through the valve member 55, as shown in FIGURE 11. These ports 61 and 62 are adapted to align alternately with the ports 51 and 52 in the housing wall and thereby alternately connect the chambers 12 and 13 with atmosphere.

The insert member 60 also has a recessed chamber 65 that communicates with the vacuum or subatmosphere port 50 in the housing wall and is adapted to alternately connect the port 59 with the port 51 as shown in FIG- URE 11 when the valve member 55 is in the position shown in FIGURE 1, or to connect the port 50 with the port 52 when the valve member 55 is in the position as shown in FIGURE 9, and thereby alternately connect chambers 12 and 13 with the vacuum or subatmosphere port 50. From FIGURE 11 it will be apparent that when chamber 12 is connected with the subatmosphere port 50, chamber 13 will be connected with atmosphere, and that when the valve member 55 shifts to its opposite position, that chamber 13 will then be connected with the subsatmosphere or vacuum port 50 while chamber 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 the pistons 20 and 22 in their respective cylinders 19 and 21.

The valve 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 the piston 2%.

As mentioned above, provision of a low coeflicient of friction plastic insert member between the planar face 59 of the valve 55 and the planar surface 54 of the housing 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.

The piston 20 has radial annular shoulder portions 70 and 71 that engage a finger member 72 secured on a rock shaft 73 pivotally mounted in the extension 74 of the housing member 1% as shown in FIGURE 6. Thus the end portion 75 of the rock shaft 73 oscillates from a position shown in FIGURE 1 to a position shown in FIGURE 9 as the shoulder portions 70 and 71 alternately engage the finger 72 and move it from the position shown in FIGURE 2 to the position shown in FIG- URE 10.

The end portion 75 of the rock shaft 73 extends through a lever 76 through a slot 77, lever 76 being pivoted on housing portion 74 by means of a pivot screw 78. Thus the lever 76 is oscillated about the pivot 78 from the position shown in FIGURE 1 to the position shown in FIGURE 9 in accordance with oscillation of rock shaft 73. V

The free end of the lever 76 has a slot 178 through which a pin 79 extends from the secondary lever 8i) that is carried on the pivot screw 56 which also supports the valve member 55 as shown in FIGURE 6. Oscillation of the lever '76 by the rock shaft 73 also occasions oscillation of the intermediate member 80 about the pivot screw 56 from the position shown in FIGURE 1 to the position shown in FIGURE 9. A compression spring extends between the end portion 75 of the rock shaft and the pin 79 mounted on the intermediate member St), so that as the lever 76 moves from the position shown in FIGURE 1 through a position shown in FIG- URE 7, the spring 35 moves over the axis center of the pivot screw 56 resulting in the snap action movement of the intermediate member 86 to engage the valve 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 the chambers 12 and 13 in the manner heretofore described.

The intermediate member 80 is adapted to engage the stop 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 the lever 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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