US3040766A - Pneumatic relay system - Google Patents

Description

June 26, 1962 R. w. COUFFER, JR, ETAL 3,040,766

PNEUMATIC RELAY SYSTEM Filed Feb. 9, 1959 2 Sheets-Sheet 1 Lye Elm-'5 fioberf W Coal/1%? Jr Joseph M. A/gizzo June 26, 1962 R. w. COUFFER, JR., ETAL 3,040,766

PNEUMATIC RELAY SYSTEM Filed Feb. 9 1959 2 Sheets-Sheet 2 be Elm- 5 foberf W flouff'er (/2? Joseph M. A/yino United States Patent 3,048,766 PNEUMA'EEHC RELAY SYSTEM Robert W. Con er, 3:2, Oak Park, and Joseph M. Algino, Chicago, 113., assignors to The Dole Valve Company, Morton Grove, Iil., a corporation of Illinois Filed Feb. 9, 1959, Ser. No. 792,085 1 Claim. (U. 137-102) This invention is directed generally to pneumatic relay systems and the like and is more particularly directed to a pneumatic relay system particularly adapted to be used in controlling the electric and pneumatic actuation of various mechanisms such as might be found in a washing machine.

In recent years it has been found to be quite advantageous to control the operation of various component parts of washing machines, such as the agitator mechanism, the shut off and/ or mixing valve, the cycling mech-' anism, etc. pneumatically and to provide a central pneumatic relay system coupled with a suitable timing mechanism to efifect actuation of each of these components.

It will be understood that such pneumatic systems require a pneumatic pump to feed pressurized air to the timing device or to the individual pneumatically controllable mechanisms and that a power source must be utilized to drive the air pump of the pneumatic system. In the past, such pneumatic pumps have generally been driven through separate electric motors and gear reduction units or have been driven off the main washing machine motor itself constantly throughout the washing machine cycle. The foregoing means for driving the pneumatic pump have not proved entirely satisfactory, however, for the following reasons: Washing machine motors, as is well known in the art, are generally one-third horsepower units, or less, and are frequently used to full capacity at various points in the cycle of operation of the washing machine so that any additional load which the motor might be subjected to, such as the load applied in operating a pneumatic pump, would tend to overload the motor and the machine would stop. For exemplary purposes, it will be noted that the main motor might be used to full capacity in a situation wherein the machine cycle is stopped by the operator and is again restarted during the rinse operation so that the motor must bring the tub full of water and clothes up to the spin speed. Furthermore, it would obviously not be economically practical to substantially increase the horsepower of the main washing machine motor simply to power a pneumatic pump. In this same regard, it is obviously not economically practical to provide a separate electric motor and gear reduction unit for driving the pneumatic pump for a pneumatic relay system as has been done in the past.

Mindful of the foregoing and in an attempt to obviate the disadvantageous features set forth above, applicant has devised a pneumatic relay system including a pneumatic pump wherein the pump is driven intermittently by the main washing machine motor but wherein the main motor is not utilized to operate the air pump during'those intervals when machine loads are applied to the motor.

In general applicants pneumatic relay system, which is hereinafter set forth with particularity, includes a pneumatic pump having a reciprocably movable compressor diaphragm therein and having a reservoir associated therewith which is associated with the main washing machine motor in such a manner that the compressor diaphragm is arranged to be reciprocably driven by the motor. The pressure reservoir associated with the pneumatic pump is communicable with a control valve which is operable to selectively direct pressurized air to a main pneumatic line leading to a pneumatic timer or similar ice control device. The control valve is arranged to close communication between the reservoir associated withthe pneumatic pump and the main pneumatic line until the pressure within the reservoir has been built up to a predetermined level by reciprocation of the diaphragm within the pneumatic pump and is thereafter operable to open communication between the reservoir and the main pneumatic line to direct pressurized air to the pneumatic timer within the washing machine from whence it is subsequently diverted to its point of utilization. In the embodiment of the invention illustrated in the drawings appended to this specification a pressure regulator is shown as being situated Within the main pneumatic line to maintain the pneumatic pressure in the line on the downstream side thereof at a preselected maximum.

The atmospheric inlet to the pneumatic pump has a check valve associated therewith which is operable to permit unidirectional air flow into the compression chamber of the pump which, in turn, has an air operated valve as.- sociated therewith which. is effective to close communication between the atmosphere and the compression chamber of the pneumatic pump. A second check valve is also seated within the pneumatic pump which is effective to permit unidirectional air flow from the compression chamber of the pump into the pressure reservoir. When the check valve at the inlet to the pump is closed, upward movement of the diaphragm within the pneumatic pump will effect compression of the air within the compression chamber to force the same through the second mentioned check valve and into the reservoir but a vacuum will be created within the compression chamber to thereby hold the diaphragm in its compression-stroke position to thereby inactivate the diaphragm thus releasing the pneumatic pump load from the main washing machine motor.

The control valve which forms a part of the presen invention comprises generally a valve body hawng a diaphragm chamber and a cylinder formed therein in axial alignment with one another. A flexible diaphragm, extends across the interior of the diaphragm chamber to divide the diaphragm chamber into an air and a spring chamber on opposite sides of the diaphragm and is operably connected, through a motion translation member, to a spool valve disposed within the cylinder. inder has an inlet and a pair of outlets spaced longitudinally along the cylinder which are each communicable with the interior thereof. The cylinder inlet is adapted to be connected to a source of pressurized air, such as the pneumatic pump hereinbefore described, While'one of the cylinder outlets is communicable with the interior of the air chamber on one side of the diaphragm to urge the diaphragm and consequently the spool valve in a first direction. 'Spring means are disposed within the spring chamber to bias the diaphragm in an opposite direction and to normally maintain the spool valve in a position closing communication between the cylinder inlet and the second outlet from the cylinder, which is connected to the main pneumatic line.

A small atmospheric bleed orifice is formed through the valve body which is communicable with the interior of the spring chamber. the air chamber from the cylinder inlet, the increasing force of pressurized air within this chamber tends to compress the spring acting on the opposite side of the diaphragm and to move the diaphragm against the opposing biasing force thereof. Movementof the diaphragm in this mannerwill, however, tend to compress the air within the spring chamber so that both the force of the spring and the pressurized air within the spring chamber will oppose the oppositely directed force of pressurized air within the air chamber. The volume of air The cyl-v As pressurized air is directed to FIGURE 1 is aview within the spring chamber will, of course, be gradually reduced as air is bled from the chamber through the atmospheric bleed orifice but this-flow of air will be relatively small due tothe' size of the orifice so that a time lag or hysteresis effect is incorporated in the operation of the diaphragm.

During the interval when the diaphragm is thus beginning its downward movement within the diaphragm chamber the pneumatic pressure within the air chamher and the compressor reservoir will be constantly increasing. When the pneumatic pressure within the air chamber finally becomes suflicient to overcome the oppositely directed force of the pressurized air and the spring within the spring chamber, the diaphragm will be moved downwardly within the diaphragm chamber to effect movement of the spool valve to a position to open communication between the cylinder inlet and the second cylinder outlet to thereby communicate pressurized air from the compressor reservoir to the main pneumatic line.

When pressurized air is directed to the main pneumatic line air is directed to the air operated valve associated withthe inlet check valve'in the pneumatic pump and the inlet to the pneumatic'pump is closed and the pneumatic pump is uncoupled from themotor in the manner which has hereinbefore 'been described. Thus, the pneumatic pumpis inactivated until the pneumatic pressure within the main fluid line and the compressor reservoir has been reduced sufficiently to the point wherein the spring associated with the diaphragm will move the diaphragm and the spool valve associated therewith in a direction to vent the main pneumatic line to the atmosphere and effect opening of the inlet to the pneumatic pump to initiate another pump operating cycle.

An electrical switch is also associated with the pneumatic relay system to control the energization of various electrical components in the washing machine such as,

for instance,-the pneumatic timer mechanism, and is so arranged that the switch is closed to energize the various electrical components only during those intervals when the pneumatic pump is inactivated and so that upon activation of the pump by the main washing machine motor, the electrical contacts in the switch are opened to deenergize the electrical components associated therewith.

Accordingly, it is a principal object of the present invention to provide a pneumatic relay system particularly adapted to control the pneumatic and electrical actuation of various components in a washing machine.

A further object of the present invention is to provide a pneumatic relay system having a pneumatic pump associated therewith which is intermittently driven by the main washing machine motor only during hose intervals .when little or no machine load isapplied to the motor.

A still further object of the invention is to provide a control valve associatedwith a pneumatic relay system of the type herein described which is operable to close communication between the compressor reservoir associated with the pneumatic pump and the main pneumatic line until a predetermined fluid pressure has been built up within the compressor reservoir and to thereafter open communication therebetween until the pneumatic pressure th ecompressor reservoir has been reduced to others inside'elevation, and stillothers in vertical sec- 7 FIGURE 2 is a vertical sectional view through a control valve constructed in accordance with the principles of the present invention and showing the diaphragms and spool valve therein in a first'position;

FIGURE 3 is a fragmental vertical sectional view of the control valve illustrated in FIGURE 2 but showing the diaphragms and spool valve in a second position;

FIGURE 4 is a vertical sectional view through the check valve which is utilized in the illustrated embodiment of the present invention; and

FIGURE 5 is another vertical sectional view through the check valve illustrated in FIGURE 4 but taken on a plane perpendicular to that of- FIGURE 4.

In the embodiment of the invention illustrated in the drawings, there is shown diagrammatically a main washing machine motor 10 which is operativ ely associated with a pneumatic pump 11 to drive the same. The pneumatic pump includes generally a compressor 12 and a compressor reservoir 13.

A pneumatic control valve 14 is associated with the compressor reservoir 13 and is adapted to controllably direct pressurized air from the compressor reservoir 13 to a main pneumatic'line 15. The main pneumatic line 15 has a pressure regulator 16 associated therewith which is adapted to maintain a constant maximum pressure on the downstream side thereof Within the pneumatic lines but which, it should be noted, is not an essential element in the pneumatic relay system which forms the subject of the present invention. 7 A branch pneumatic line 17 leads from the main pneumatic line, on the downstream side of the pressure regulator 16, to the compressor 12 to control the operation of the compressor in a manner which will hereinafter be more fully described in detail.

The compressor 12 comprises generally a valve block 20 to which a reservoir housing 21 is sealed by means of a gasket 22. The reservoir housing 21 may be secured to the block 20 in any suitable manner. An inlet port 23 is formed within the valve block in communication with the line 17 while an outlet port 24 is formed therein in communication with the interior of the reservoir housing 21.

A compression chamber 25 is formed and defined by a recessed portion in the bottom of the valve block 20 and by a flexible diaphragm 28 which extends thereacross. Preferably the diaphragm 28 has an outer annular raised bead 29 which is seated in a mating groove 30 formed in the valve block 20.

The diaphragm 28 may be made out of rubber or any one-of the known substitutmtherefor and is provided with a reefiorced central portion which is formed with an annular disk 31 held on the underside thereof by means of a depending lip 32 of the diaphragm 28.

A base plate or cap 33 extends over the diaphragm member 28 and retains the marginal edge thereof seated against the valve block 20. The base plate 33 includes a cup portion 34 and av hollow stem portion 35 which receives a reciprocable power shaft 36. An air vent 37 is provided in the base plate 33 to keep the underside of the diaphragm 28 in communication with the atmosphere to prevent pressure buildup intermediate the diaphragm 28 and the base plate or cap 33,

The power shaft 36 is operatively connected at its upper end to the diaphragm 28 and at its lower end to a yoke 38 within which is mounted a pin 37a rotatab'ly supporting a cam follower wheel 39. An annular disk 40 carried by the shaft 36 at its lower end portion provides a reaction means for a compression spring 41 which extends between the cap member 33 and the annular disk 40.

The wheel or roller'39 rides on a cam 45 formed on the upper surface 46 of a cam wheel 47. The cam wheel .47 is rotatably supported on an output power shaft 48 of the main washing machine motor 10 and is rotatably driven thereby.

An outlet check valve 50. is seated within the outlet port 24 on an annular flange 51 formed integrally with the valve block 20 and is maintained in seating engagement therewith by means of a cylindrical ring 53 which frictionally engages the sidewall of the port 24. It will here be noted that the outlet check valve 50* is, arranged to permit only unidirectional flow from the compression chamber 25 to the reservoir 21. Similarly, an inlet check valve 55 is seated within an enlarged diameter portion 56 of a fluid inlet passageway 57 which is arranged to provide fluid communication between the inlet port 23 and the compression chamber 25. It will further be noted that a flexible diaphragm 58 has a peripheral bead 59 seated within an annular groove 60 formed within the valve block 26 and that a valve member 61 is suitably centrally secured to the diaphragm 58 in coaxial alignment with the central passageway in the inlet check valve 55 to control fluid flow therethrough in a manner which will hereinafter become more fully apparent. The diaphragm 58 is normally urged to the position illustrated in FIGURE 1 by a spring 58a and is moved in an opposite direction by fluid pressure as will hereafter be described.

The check valves 50 and 55 are alike and each includes a valve body 62 formed of rubber or the like. The valve body 62 has a depending somewhat flattened hollow portion 63 which is generally of rectangular cross-section. Member 63 has an elongated passageway 64 therein in communication with a central passageway 65 in direct alignment therewith. Disposed within the hollow portion 63 is a pin 66 which extends lengthwise thereof and which is snugly retained at opposite ends by the end walls of the portion 63. The sidewalls of the portion 63 in conjunction with pin 66 form a valve to restrict the passage of air through the unit. Pin 66 has its opposite ends rounded as at 67 where it engages the opposite ends of passageway 64 and slightly stretches the member forming that passageway. Two depending tongues 63 extend downwardly toward pin 66 and serve to properly locate pin 66.

Whenever the pressure around the outside of the elongated passageway member 63 is less than the air pressure at the inlet 70 of the check valve, the walls of the passageways 64 yieldably expand and spread apart to permit the movement of air past the pin 66 to the outlet '71 of the check valve. When, however, the pressure surrounding the elongated passageway portion 63 is greater than the air pressure at the inlet 70 of the check valve, the greater air pressure on the exterior of the passageway member 63 will collapse the walls 63 and prevent the passage of air past the pin 66.

It will thus become-apparent that the valve member or plunger which is connected to the diaphragm 58 acts as a valve and is arranged to open and close the inlet 79 of the inlet check valve 55.

The operation of the pump is somewhat as follows: Assume, for illustrative purposes, that the cam wheel or roller 39 is resting on the cam Wheel 47 at the beginning of the cycle of operation. As the cam wheel 47 is rotated, cam roller 39 will ride up onto the high portion of the cam which, in turn, will force shaft 36 upwardly against the action of spring 41 and the diaphragm 28 will be moved upwardly into juxtaposition with the uppermost portion of the compression chamber 25. The spring member 41 will act to return the roller39 to the level illustrated in FIGURE 1 upon further rotational movement of the cam wheel 47. Since the outlet check valve will not permit the passage of air from the reservoir chamber to the compression chamber '25, a partial vacuum will be formed within the compression chamber causing the air on the inlet side of check valve to expand the sidewalls of the check valve to open the air passageway into the compression chamber 25 and permit the flow of air thereto from the atmosphere. When the power shaft 36 and the diaphragm are again raised to their uppermost position by the cam 45, the increased pressure of air caused by the piston action of the upwardly moving diaphragm on the outer walls of the inlet check valve will be greater than the pressure on the inlet side of the valve 55, and the inlet check valve 55 will close. on the upstroke of the diaphragm the pressure at the inlet '70 of the outlet check valve 24 will be greater than the pressure surrounding the elongated passageway walls and thus air will pass through the valve from the compression chamber 25 to the reservoir 21.

Upon closure of the inlet check valve 55 by the valve member 61 associated with diaphragm 58, the diaphragm 28 will be rendered inoperative after moving through its compression stroke since a vacuum will be created above the diaphragm so that the air pressure acting upwardly on the diaphragm and communicated to the underside of the diaphragm through the vent port 37 will be sufliciently great to overcome the opposing biasing force of spring member 41. The diaphragm 28 will thus remain in its upper position so long as the inlet check valve 55 remains closed by valve member 61. Thus, even though the cam wheel 47 is rotating, the diaphragm will not be moved and no additional air will be forced into the accumulator chamber or reservoir 13. Accordingly, the load of driving the pneumatic pump 11 will be released from the main motor 10.

Referring now particularly to FIGURES 2 and 3 of the drawings, the control valve 14 is shown as comp-rising generally -a valve body 80 having a diaphragm chamber 81 and a cylinder 82 formed therein in coaxial alignment with one another. An inlet nipple 83 and a pair of outlet nipples 84 and 85 are formed integrally with the valve body 80 and have passages formed axially therein which are communicable with the interior of the cylinder 82. The inlet nipple 83 is adapted to be connected to a suitable hose or tube 86 which is, in turn, suitably connected to the reservoir 13 to communicate pressurized air from the interior of the reservoir to the cylinder 82. Another connecting nipple 87 is formed integrally with the valve body 80 and has a passage formed axially therein which opens to the interior of the diaphragm chamber 81 and which is adapted to be connected to a suitable hose or tube 89 which, in turn, is connected at its opposite end to the nipple 84 and which is adapted to communicate air from the interior of the cylinder 82 to the diaphragm chamber 81.

An annular groove 90 is formed about the side wall of the diaphragm chamber 81 which is adapted to receive and form a seat for a thickened peripheral head 91 of a flexible annular diaphragm 92. The flexible annular diaphragm 92 thus extends entirely across the interior of the diaphragm chamber 81 and divides the chamber into an air chamber 92 and a spring chamber 94. In this regard, it will be noted that the connecting nipple 87 is so positioned that the axial passage therein opens to the air chamber 93.

It will also be observed that a stiffening plate 95 is molded within the diaphragm 92 but that the plate has a diameter somewhat less than the diameter of the chamber 31.

Coaxial apertures 96 and 97 are formed within the valve body 80 within which a motion translation rod 98 is disposed. An annular groove 99 is formed Within the valve body 30 about the aperture 96 and is adapted to form a seat for an O-ring 100 which is disposed therein to maintain a fluid tight seal between the motion translation rod 98 and the wall portion of the valve body 80 defining the aperture 96.

It will be understood that the motion translation rod 98 is suitably affixed to the diaphragm 92 so that it will move colinearly therewith and that the upper end portion of the rod 98 is arranged to abut the upper wall portion of the valve body 80 defining the diaphragm chamber 81 to limit theupward movement of the diaphragm 92.

A pair of valve members 102 and 103 are afiixed to the motion translation rod 98 in spaced relation with However,

respect to one another and are disposed within the cylinder 82 and slidably engage the inner wall of the cylindert82.

It will further be understood that the valve members 102 and 103 form, in conjunction with that portion of the motion translation rod 98 extending intermediate the valve members, a spool valve 105 which is movable within the cylinder 82 to selectively communicate pressurized air from the inlet 83 to the outlets 84 and 85.

Thus, when the spool valve 105 is in the positoin illustrated in FIGURE 2, pressurized air is communicated from the compressor reservoir 13 to the outlet84 and then from the cylinder 02, to the air chamber 93 on the upper surface of the diaphragm 92. It will be noted that when the spool valve is in this position, no pressurized air is communicated from the compressor reservoir 13 to the outlet 85 due to the positioning of the valve memher- 103 intermediate the inlet 83 and the outlet 85, and the main pneumatic line is, as a result, vented to the atmosphere through a vent port 107 which is suitably formed within the valve body 80 at the lower end of the cylinder 82. p i

.A spring member 106 is disposed within the spring chamber 94 intermediate a wall portion of the valve body 80 and the diaphragm 92 which is efiective to oppose the pneumatic force within the air chamber 93 and urge the diaphragm 92 upwardly within the diaphragm chamber 81. A vent port 108is also formed through thewall of the valve body 80 to communicate the interior of the spring chamber 94 with the atmosphere which is operable to eliect hysteretic movement of the diaphragm in a manner which will hereinafter be described in more detail.

An electrical switch 110 is disposed at the lower end of the cylinder 82 and comprises generally a mounting bracket 111 which is suitably aflixed to the valve body 80, and a pair of electrical contacts 112 and 113 which are disposed in spaced relation from one another and which are suitably aifixed to the bracket 111. It will be noted that the contact 112 is engaged by the protruding outer end portion of the motion translation rod 98 so that reciprocable movement of the rod 98 will act to move the contact 112 into and out of engagement with the contact 113 to thereby open and close an electrical energizing circuit through the switch 110.

It will here be understood that the bleed passage 108 which functions to communicate the interior of the spring chamber 94 with the atmosphere, is made extremely small 'so that-a relatively small rate of air flow is permittedtto pass therethrough. In this manner, while the constantly increasing'force of pressurized air within the air chamber 93 might be sufiicientto compress the spring member 106 the diaphragm will not move downwardly at once, since the pneumatic pressure within the spring chamber 94 will also be resisting downward movement of the diaphragm 92. Gradually, air will be forced out of the spring chamber 94 through the vent port 108, but by this time the pneumatic pressure within air. chamber 93 and reservoir 13 will be quite large. Thereafter, upon movement of the diaphragm 92 downwardly within the diaphragm chamber 81, the spool valve 105 willbe moved from the position illustrated in FIGURE 2 to the position i illustrated in FIGURE 3-to thereby open communication between the inlet 83 and each of the outlets 84' and 85. It will be noted that when the valve member 103 has been moved to the position illustrated in FIGURE 3, to

openrcommunication between the inlet 83 and the outlet 85, communication between the vent port 107 and outlet 85 will be closed. V 7

Conversely, even when the pneumatic pressure within the reservoir 13, the main pneumatic line 15, and the air chamber 93 has been reduced to a point below that of the force of spring member 106 tending to urge the diaphragm 102 upwardly within the chamber 81, the'diaphragrn. 92 will not immediately move upwardly a substantial amount since a partial vacuum will be created within the spring chamber 94 due to the relatively small rate of air flow through the orifice 108.

In this manner, a time delay feature or hysteresis effect is incorporated in the pneumatic relay system so that a relatively high pneumatic pressure will be built up within the reservoir 13 before the interior thereof is communicated with the main pneumatic line 15, and the compressor reservoir 13 will be maintained in communication with the pneumatic line 15 until a relatively low pneumatic pressure has been reached within the reservoir 13.

In general, the operation of the entire pneumatic relay system will be somewhat as follows: Assuming that the washing machine motor 10 has just been started and the pneumatic pressure within the reservoir 13 is relatively low, rotatable movement of the cam wheel 47 will effect reciprocable movement of the power shaft 36 to operate the compressor 12 and to thereby force compressed air into the reservior 13. The various parts of the control valve 14 will be in the position illustrated in FIGURE 2 and the pressurized air within the compressor reservoir 13 will be communicated through the cylinder 82, and the outlet 84 to the air chamber 93 on the upper surface of the diaphragm 92. When the pneumatic force within the air chamber 93 tending to urge the diaphragm 92 downwardly within the air chamber 81 exceeds the opposing biasing force of spring member 106, the diaphragm will begin to move downwardly within chamber 81 but such downward movement will soon be slowed due to the air pressure buildup within the spring chamber 94. The pneumatic pressure Within chamber 94 will gradually be reduced as air seeps slowly therefrom through the bleed orifice 108, but during that interval the pneumatic pressure within compressor reservoir 13 an air chamber 93 will be constantly increasing. Finally, the diaphragm 92 will be moved downwardly to the position illustrated in FIGURE 3 due to the differential forces acting on opposite sides of the diaphragm 92 and the outlet 85 and the main pneumatic line 15 will then be communicated with the interior of the compressor reservoir 13. Thus, pressurized air will flow from the reservoir 13 to the main pneumatic line 15 from whence pressurized air will be bled from time to time.

When the spool valve 105 has been moved to the position illustrated in FIGURE 3 to open communication between the interior of the compressor reservoir 13 and the main pneumatic line 15, pressurized air on the downstream side of the pressure regulator 16 will be communicated to the underside of the diaphragm 58 to move the diaphragm and the valve member 61 associated therewith into juxtaposition with the inlet check valve 55 to effect closure of the inlet check valve and to thereby maintain the diaphragm 28 and the power shaft 36 associated therewith intthe raised or compression stroke position to thereby release the pneumatic pump load from the main washing machine motor 10.

It will further be apparent that upon movement of the motion translation rod 98, downwardly within the valve body 30, the movable electrical contact 112 of switch 110 will be moved into engagement with the contact 113 to thereby close an electrical energizing circuit to an electrically operated device connected therewith which, for illustrative purposes, may comprise an electrically operated pneumatic timer As hereinbefore described, the diaphragm 92 will not begin to move upwardly within the chamber 81 immediately upon the reduction of the pneumatic pressure in the chamber 93 below that of the opposing biasing force of spring member 106 since a partial vacuum will be created in spring chamber 94. The diaphragm 92 will, however, gradually begin to move upwardly within chamber 81 as pressure in chamber 93 is reduced until the spool valve has again been returned to the position illustrated in FIGURE 2. When the spool valve 105 has been returned to this latter position, the main pneumatic line 15 will be communicated with the atmosphere through the 9 vent port 197 so that the diaphragm 58 will again be re turned to the position illustrated in FIGURE 1 and the pneumatic pump load will again be impressed on the main washing machine motor 1% It Will herein be understood that in general the pneumatic pressure Within the compressor reservoir 13 will be built up to such a point that operating pressure is achieved and the pneumatic pump load is released from themain Washing machine motor before the tub filling cycle of the washing machine has been completed so that the pneumatic pump load will be released from the main motor 10 before any substantial machine load is applied to the motor.

It will also be noted that in general the build up of pressurized air Within the compressor reservoir 13 at the beginning of the Washing machine cycle will be sufiicient to supply pressurized air to the various pneumatically operated components of the Washing machine throughout the entire cycle of the machine so that the pump 11 need not again be operated during the Washing machine cycle.

It Will further be understood that this embodiment of the invention has been used for illustrative purposes only and that applicants pneumatic relay system may find varied uses in devices other than Washing machines, and that various modifications and variations in the present invention may be efiected Without departing from the sprit and scope of the novel concepts thereof.

We claim as our invention:

A pneumatic control valve comprising a valve body having a diaphragm chamber and a cylinder formed therein, an inlet adapted to be connected to a source of pressurized air and a pair of outlets opening to said cylinders, a diaphragm extending across said chamber and peripherally sealed to a wall thereof forming an air chamber and a spring chamber on opposite sides thereof, I

spring means Within said springchamber biasing said diaphragm in one direction, means communicating pressurized air from one of said outlets to said air chamber, a motion translation member connected to said diaphragm slidably mounted Within said valve body and extending into said cylinder, a valve associated With said motion translation member and disposed Within said cylinder operable to selectively communicate pressurized air from said inlet to the other of said outlets, an atmospheric bleed orifice formed Within said valve body opening to said spring chamber and effective to permit a restricted flow of air therethrough such as to provide a time delay action for said diaphragm in response to variations in the pressure of air from said source of pressurized air appliedto the diaphragm through said one outlet, and a vent port opening to said cylinder and positioned to communicate with the other of said outlets when said valve is disposed to prevent communication of pressurized air from said inlet to the other of said outlets and to be closed from said other of said outlets by said valve when said valve affords communication of pressurized air from said inlet to said other of said outlets.

References Cited in the file of this patent UNITED STATES PATENTS Mueller et al. Dec. 31,

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