US2833219A

US2833219A - Hydraulic converter

Info

Publication number: US2833219A
Application number: US450774A
Authority: US
Inventors: George W Lewis
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-08-18
Filing date: 1954-08-18
Publication date: 1958-05-06
Anticipated expiration: 1975-05-06

Description

y 6, 1958 G. w. LEWIS 2,833,219

HYDRAULIC CONVERTER Filed Aug. 18, 1954 2 SheetS -Sheet 1 30 ,2 0 o 29 2 D 25 H i i2 I6 Z3 Z5 4,2.J 4/ 5,2

57 x 65 42 67 6/ 7: 60 7/ 88 73 70 49 :2 7 74 8/ Q 78 79 E A 76 I05 I05 P IN V EN TOR.

74 George W Lewis T M \J 73 I :1-

United States PatentD 7;

HYDRAULIC CONVERTER George W. Lewis, Toledo, Ohio Application August 18, 1954, Serial No. 450,774

Claims, (Cl. 10350) This'invention relates to fluid pressure apparatus and more particularly to means and method for eflecting the conversion of low sub-atmospheric fluid pressure to a substantially high super-atmospheric fluid pressure which has particular utility as a source of power for the operation of accessories of self-propelled vehicles.

The invention comprehends a power system in which fluctuating subatmospheric fluid pressure of very low value is used as imput means for establishing a liquid at high super-atmospheric maintained within predetermined values as its output to provide a substantially constant hydraulic power source.

The invention comprises a means and a method whereby variable fluid pressure of low value such as engine manifold vacuum is converted into hydraulic pressure of high value regulated and maintained within predetermined limits to provide an ample source of hydraulic power at a pretetermined high value permitting periodical withdrawals in relatively large amounts.

The invention contemplates apparatus for the production and storage of power involving a pressure generating or pumping mechanism operated by motor means actuated by engine manifold vacuum for charging a pressurized accumulator, which pressure generating or pumping mechanism is automatically stalled when a predetermine pressure is reached.

The invention embraces an integrated assembly inwhich are structurally combined a container for a liquid at substantially atmospheric pressure directly connected to a pumping mechanism operable by engine manifold vacuum for charging a pressurized reservoir which provides a source of supply of an ample quantity of liquid at a'predetermined working pressure.

The invention is concerned with a self regulated energy converting and storing unit for pressurizing a motive medium into small space to establish its working pressure and accumulating a reserve which is automatically replenished so that the working pressure of the motive medium is maintained even though the rate of delivery materially exceeds that of accumulation.

The invention includes an inherently self-regulating ,hydraulic unit comprising a diaphragm motor operated by the intermittent application of engine manifold vacuum in which its diaphragm is connected to ,a spring-loaded plunger for establishing the operating pressure of the motive fluid by charging a pneumatically pressurized accumulator. Thecomponent parts of the unitare very inexpensive to make,.highly suitablefor mass production manufacture, producing an assembly of great simplicity, very quiet in operation, and having comparatively small overall dimensions. 7

According to the foregoing summary of theinvention indicating its general nature and substance, one of its objects is to provide apparatus which produce a high pressure hydraulic power supply systembyconverting fluctuating sub-atmospheric fluid pressure of low value Patented May 6, 19 58 predetermined limits as a source of motive power of -by-a pneumatic source wherein no adverse interference takes place between the pneumatic andhydraulic sources or the eflicient operation of the respective components. Another object of the invention is to provide a system including means for the production and storage of hydraulic power, providing an ample supply and an instantaneous delivery of a motive fluid at a desired-working pressure maintained within predetermined limits without the use of conventional valving mechanisms.

Another object of the invention is the provision of a self. contained conversion power unit of relatively small size in which a non-compressible fluid is pumped from a reservoir maintained at atmospheric pressure into a pressurized tank functioning to establish a predetermined working pressure and automatically replenish the-amount of fluid stored in the pressurized tank so as to maintain an ample supply. 1

' Another object of theinvention is the provision of a power unit comprising a plurality of detachable subassemblies which are designed for .independent calibration and for quick'and effective assembly to produce a :hermetically sealed unit where maximum utilization of space is accomplished.

Aufurther object of the invention'is to provide an economically manufactured self-integratedpower unit formed of detachable sub-assemblies eflectively joined in axial alignment and which can be easily and quickly assembled and disassembled for inspection-and substitution, as well .as for service and replacement in the field without the use of-complex equipment or special tools. A further object of the invention is the provision of an integrated power. unit in whichare. structurally combined and axially positioned a diaphragm motor, voil pumping mechanism, and pressure accumulator and wherein the pumping mechanism .is surrounded by liquid'retained in a-reservoir forming an outer housing providingfla'weatherproof assembly.

Still a further object of the inventioniis to provide an integrated assembly in which are structurally combined a reservoir for a liquid at atmospheric pressure directly connected and surrounding a pumping mechanism which .derives its actuating power from motor means: responsive and actuated by; engine manifold vacuum to charge a pressurized accumulator, the latter providing an ample sourceof supply of liquid under pressure as tlremotive power.

Otherobjects and advantages of this invention relating to the arrangement, operation and function'ofthe'related elements of the structure, to various details of construction,- to combinations of parts and to economies of manufacture, will be apparent to those skilled in the art upon consideration; of the following description and appended claims, reference being hadto theaccompanying drawings forming apart of this specification wherein like reference characters designate corresponding-parts in theseveral views.

Fig. I is a side view illustrating the device of the invention andits connection to an engine;

Fig, ,II is. across sectional view of the device incorporati nga form of the invention shown in Fig. I;

such as the engine manifold vacuum, into hydraulic pressure of high value regulatedand maintained within gzEig. ,-I II- i s enlarged fragmentary view. ofnthe control valves for the pumping mechanism;

Fig. IV is across sectional, view taken on line's'lv lv of Fig. III looking in thedirection of the arrows.

Fig. V is an enlarged fragmentary view of the valving nection between the pneumatic motor ,and .thepumping mechanism;

Fig. VIII is an enlarged fragmentary view showing connecting members in assembled relation;

Fig. IX is a cross sectional view of a device incorporating a modified form of the invention;

Fig. X is a top plan viewof the device shown in Fig. IX;

Fig. XI is an enlarged detailed view of the control valves for the pumping mechanism shown in Fig. IX.

Fig. XII is an enlarged top planview of one of the control valves .of the pumping mechanism .shown in Fig. XI. a

The drawings show illustrative embodiments of the invention indicating a few. of the various ways in which its principles can be mechanically expressed. However. it

is to be. understood that the invention should not be limited to the arrangements disclosed, but it is contemplated to use the principles of the invention in any other arrangements mother uses whenever the same may have been foundtobe applicable. J

In the practice of the invention toprovide a hydraulic power system to supply a high working force for assisting .the driver of an .automotivevehicle in the effective operation, :ofits controls and in the operation of other components or accessories,.soas to materially reduce the efiort exerted by the driver, the apparatus and components of the systemxhave beendesigned to fully incorporate minimum weight and space for a given work capacity as wellas trouble-free operation. Incorporating these factors in the invention illustrated in the drawings there is provided alight weightand compact inherently regulated pressuregenerating unit for etfecting the conversion of the engine manifold vacuum into comparatively high hydraulic pressure .of substantially constant'value without the necessity of. conventional unloading pressure regulating and relief valves The conversion or pressure gencrating unit' broadly comprises three separablecompon- .ents which may be. termed as'a pneumatic motor or low fluid pressure. motor means; a non-compressible fluid-supply and pumping mechanism or hydraulic pressure generator means; and a'gas pressurized reservoir or accumulator forming the high pressure hydraulic'storing and supply means of the system, to providean ample quantity of liquid at a predeterminedworking pressure maintained substantiallyconstant within predetermined limits.

The low fluid pressure motormeansorthe pneumatic motor is preferably of the reciprocating type provided with an output or work-preforming member, the latter is actuated by displaceable means which are resiliently biased to the work-preforming position; The displa'ceable means are moved to the energy-storing position causing the distortionofitsresilient biasing means when subjected to pressure difierential obtained byithe application of the engine manifold vacuum and thereby effect the translation of the engine manifold vacuum into mechanicalpowef.

The application of the engine manifold 'vacuurrr is periodically interrupted touproduce the reciprocationof the work-performingmember of the pneumatic motor. The interruption of the engine manifold vacuum to the displaceable means of the pneumatic motor instantaneously releases, as a driving force, in the resilient means. a I

The instantaneous release of the mechanicalpower stored by the application of engine manifold-vacuum to the mechanical power stored the expansible means of the pneumatic motor is utili'zed to operate the liquid pumping mechani sm orhydraulic pneumatic motor casing.

pressure generator, whereby, mechanical power is transferred into hydraulic power by pressurizing a liquid, forcing and storing the same into the accumulator or the the high-pressure hydraulic storing and supply means. The utilization of resilient means as a driving force for the power stroke of the hydraulic generator, provides means whereby the translation or transfer of mechanical power into hydraulic power is inherently regulated when the pressure of liquid in the accumulator reaches a predetermined value and in addition serve as means, depending for its function upon the hydraulic power used, to constantly maintain an ample supply of liquid under pressure in the'accumulator.

Referring to the drawings and particularly to Figs. 1 and II in which the connections and constructional features of a form of the invention are illustrated, an automotive variable speed internal combustion engine 10 is shown having an intake manifold 12, to which is connected by a suitable conduit, 13 the low pressure means or pneumatic motor which forms the upper section of the power unit of the invention.

The pneumatic motor of the invention is preferably of the reciprocating type in which its displaceable piston means or movable wall, as shown in the drawing, takes the form of a diaphragm 15 made of suitable flexible material clamped at its periphery by the planar bolting flanges of the two frustro-conically-shaped members 16 and 17, preferably made of sheet metal, which form the The member 16 and the diaphragm 15 form a hermetically-sealed chamber 18 supporting on the top of its planar surface 19 the automatic valve mechanism carried by the valve block 20 which is detachably mounted thereon by suitable means usch as the screws 21. The planar surface 19 is pierced, providing a centrally-located enlarged aperture 23 which allows the communication of the interior of the chamber 18 with a source of less than atmospheric pressure by the annular suction or air outlet port 24 provided on the bottom surface 25 of the valve block, which port, through the passage 26 and the conduit 13 threaded thereon, is connected to the engine intake manifold 12. In addition, the enlarged opening 23 of member 16 permits the communication of the chamber 18 with the vertically-directed passageway 27 which leads to the annular atmospheric venting or air inlet port 28 formed on the top surface 29 of the valve block.

An air cleaner and sound-deadening assembly is interposed between the atmosphere and the air inlet port 28. This asembly, as shown in the drawing, comprises a side perforated, cup-like member 30 carrying, at its inner top section, a smaller, cup-likemembcr 31 having its depending walls terminating above the valve block 20 into an outwardly-projecting peripheral flange, thereby forming an annular space 32 in which is suitably retained sound-deadening as well as filtering material.

, "The air outlet and

inlet ports

24 and 28 provided in the valve actuating mechanism which embodies a pair of planar disc-like valve members 34 and 35 interconnected by the valve stem 36. The valves 34 and 35 are alternately seated or unseated closing the corresponding ports by the movement of the diaphragm 15 through the instrumentality of a snap-over spring arrangement.

The planarvalve members 34 and 35 are inaxial alignment and the valve 34 is arranged to normally close the air inlet port 28 while the valve 35, forming an integral part of the stem 36, is unseated with respectto air outlet port 24 or held in its open position. Means are provided for adjusting valve clearances for optimum operation and also permit-alignment of the valve member with its corresponding valve seat 29 to effectively close the air inlet port 28 These means are particularly shown in Fig. V where it can be seen that the valve member 34 is mounted on the threaded end 37 of the valve stem36 and is adapted to be held in adjusted position by suitable asses- 1 9 iocking'means-such as-a'wi're passing through an opening provided in the valve stem '36 and the castellations formed ing thereby a very reliable operation of the motor. This connection and arrangement'may take the form of a pair of U-shaped members or

similarly'shaped yokes

40 and 41 facing each other and'arranged at'substantially right angles, so that their leg portions are'directed in opposite directions. The member is 'detachably connected to the threaded end 38 of thevalve stem 36 and is capable of adjustment thereon through its central threaded opening and lock'nut 42.

As particularly shown in Fig. VI, the legs ofthe 'U-shaped member 40 are provided with rectangular,

aligned apertures 43 which freely admit the passage of the end portions of the

oppositely extending arms

45 and 46 of the cross-shaped flat spring 47 which also has the ends of'its opposed

arms

48 and 49 projecting through the rectangular, aligned apertures 50' formed on the upwardly directed legs of the U-shaped member '41. The relationship of the comparatively

large openings

43 and 50 with respect to the thickness 'of the end portions of the uniplanar cross-shaped leaf spring "47 provides the limited lost motion and a resilient play connection whereby the spring performs the snap over action at the opposite limits of movement of the diaphragm for simultaneously changing the position of the valves 34 and 35.

The yoke member 41 is fixed to thediaphragm by riveting the same on top of the diaphragm reinforcing plate-52 through the upsetting of the end of the reduced shouldered portion-53 of thepneumatic motor work-performing member 54. The reduced portion 53 passes through central openings provided in the diaphragm 15 and reinforcing

plates

53 and 56 with its shoulder abutting the lower surface of plate 56 providing a rigid connection between the diaphragm 15 and output member 54 as well as means to hold the same in fixed and leakstored power to urge the output means of the motor to its work-performing position at a substantiallyconstant force or pressure of a yieldable character whereby the motor is inherently regulated to provide a predetermined driving force. The distortable resilient means may take the form of a spring 57, preferably of the compressible coil type, arranged to' surround the output member 54 with its upper end bearing against the bottom surface of the casing member 17 and retained in position by engaging the depending flange 59 which defines its central aperture. The lower end of the spring 57 is in engagement with the horizontally disposed flange 60 of the cuplike spring retainer 61 (see Figs. VII and VIII), which is connected to the output member 54 through its detachable wrist or connecting pin 62, so that the diaphragm as to provide a type of bayonet connection for its rapid and ready assembly and disassembly, and it is provided with downwardly-projecting portions 64 at right angles to the aperture 63 for holding the retainer 61 in nonremovable positiomasshown in Fig. VIII.

The pumping mechanism or hydraulic pressure gen *erator means of the invention is driven by the pneumatic "motor through a :dem'ountable power-transmitting Icon- -nection provided in the end portion of'the' work-performing member'54. This connection is shown in the form of a clevis 65 adapted to receive the planar perforated end section 67 of the cylinder plunger 68 constituting the reciprocable piston means of the hydraulicpumping mechanism. The clevis 65 and the section 67 of the .piston 68are interconnected'for power transmission-by means of the readily detachable connecting pin 62.

The piston 68 of the pressure generator is adapted for slidin movement in the central bore 69 of the hydraulic pump body 70 forming the cylinder therefor, provided at "its upper end with liquid-tight sealing means 71. "The pump cylinder 70 is provided with a lateral cylindrical aperture for the entrance of the hydraulic liquid forming the inlet port 72 which is. controlled by alight-weight ,and low-friction valve member 73 of thin metal, preferably of'square shape. The valve member 73 is operablein response to the motion of the piston 68 topermitthe entrance of the liquid into the cylinder chamber 69 when .thepiston is retracted .and closed during its pumping having its outer end 78ithreadedly connected tothe top member 79 of the accumulator housing. The. discharge passage 80 of the pump is adapted to beclosedby a oneway valve comprising ball 81 urged against its valve seat 82 by's'pring 83 suitably retained'therein.

The pumping mechanism is enclosed by a tubular member 85, preferably of thin metal which performs .the double function of connecting the pneumatically-operated motorand the pressurized accum-ulatorthrough the respective bolting flanges, and of forming a container for retaining at atmospheric pressure a supply of hydraulic liquid, preferably oil surrounding the pressure-producing mechanism. The member 85 adjacent its top section has an opening 86, to which is connected a tubular member -87 for filling the container 85 with hydraulic liquid tma predetermined level and which is closed by a vented and filter cap'provided with a level stick 88, by means of which the level of the liquid can be readily ascertained. The tubular member. 87 is also provided with a threaded opening 89, to which is connected the end of a conduit 90 used for returning thehydraulic liquid delivered/by the accumulator. The bottom flange 91 of member .85,

secured by means of suitable bolts 92 to the under side of the bolting flange 93 of the cup-like member '94 which forms the lower section of the accumulator outer shell or housing. i U

The accumulator or high pressure storing and supply means used to establish a predetermined high-Working pressure having a range including 1,000p. s. i. for the hydraulic liquid transferred therein by the pumping mechanism may take any of the conventional forms. .In the embodiment illustrated, the accumulator shown'is of the piston type permanently biased 'to oneposition by means housed therein which are preferably in theform of a compressible fluid under a predetermined pressurev and comprises a movable member or piston 95 dividing the interior of the accumulator shell into opposed

chambers

96 and 97. The chamber 96 constitutes the liquid-storing space, and the chamber 97, a compressible .cushiorn'ng spa-cc adapted to permanently contain or :becharged 'as .requiredwith a compressible fluid, preferably adryinert gas, by means of the one-way valve 98.

,assaaie The movable piston 95 of the' accumulator unit is of dome-like configuration provided with suitable sealing means to prevent interconnection between the oil storing compartment 96 and the. compressible cushioned space 97 in order to maintain the sweat their predetermined pressures The sealing means may take the form of an O-ring" 100 located in a rectangularly shaped groove 101 formed on the depending cylindrical wall section 102 of the piston which has a slidingfit with the cylindrical liner 104 secured to the inner surface of the section 94 by welding 105. The oil or hydraulic liquid transferred 7 and forced by the pump plunger 68 from the container 85 into the pressurized storing chamber 96 of the accumulator is adapted to flow out or be delivered through the passageway 106 leading by' connector 107 to the high pressure delivering conduit109 of the hydraulicpower system, providing thereby a hig-h working force at substantially constant value to assist the driver of an automotive vehicle in the operation of its controls and the accessories or power-operated assemblies hydraulically actuated. t

The operationrof the conversion power unit is believed to be apparent from the foregoing, and can be summarized as follows. With the parts arranged in powerdelivering position, as illustrated in Fig. II, the source of less than atmospheric pressure connected to the motor unit will create a negative or sub-atmospheric pressure in the chamber 18 as the inlet valve 34 is closed, and the outlet valve 35 is opened, permitting the air in the chamber 18 to be drawn and escape through the outlet port 24 and the conduit 13 into the engine intake manifold, creating a pressure differential between the chamber 18 and its surrounding atmosphere. This pressure differential causes the diaphragm 15 to be flexed upwardly, exerting a lifting force against the tension of the power spring 57, distorting the samejfor storing energy therein and concurrently retracting the piston 68 by its output working member 54 whereby oil will be drawn through the inlet port 72 into the pump chamber 69 from the supply surrounding the same.

As the diaphragm 15 is flexed upwardly, the crossshaped spring 47 is also flexed in the same direction as the yoke 40 is held stationary by its rigid conection with the air inlet valve 34 which is maintained closed by pressure from the outside atmosphere. When the diaphragm 15 reaches substantially the limit of its lifting movement or its extreme upward position, the force produced by the flexure of the cross spring 47 is sufiicient to overcome the opening resistance of the valve 34 and the central portion of the spring will produce the snap-over action to close the valve 35 and thereby stop the application of engine manifold vacuum to chamber 18 and open the valve 34, subjecting to the atmosphere the chamber 18. The opening of the valve 34 will cause air to rush through the inlet port 28 into chamber 18 under atmospheric pressure and thereby instantaneously release as a driving force the energy or power stored through the distortion of the spring 57 to'propel the diaphragm 15 and its output member 54 downwardly and effect the pumping stroke of the piston 68 of the hydraulic pressure generator of the power conversion unit.

During the initial downward movement of the pump piston 68 to produce the pumping stroke, the movement of the oil or hydraulic liquid in pump chamber 69 will force the valve 73 againstits seat 73', preventing a recession of oil into its reservoir. The pumping stroke of piston 68 will open the ball valve 81, discharging the pump chamber, whereby the oil is forced into the accumulator chamber 96 against the compressible means or pressurized gas contained in chamber 97 to establish a predetermined high-working pressure for the oil transferred and stored in chamber 96 whereby variable engine intake manifold vacuum is converted into hydraulic pressure of highvalue. It should be noted that as the diaphragm 15=moves downwardly, the leaf spring 47 is also flexed downwardly as the outlet'valve 35 is held in its closed ing mechanisms.

position due to pressure differential between the chamber 18 and the conduit 13 connected to the source of less than atmospheric pressure.

The outlet valve 35 of thepneurnatic motor will be maintained in its closed position until the diaphragm 15 reaches substantially the limit of its downward movement when the force produced by the flexing of spring 47 will be sufficient to overcome the opening resistance of valve 35 whereby the spring will effect its snap-over action, opening valve 35 and simultaneously closing valve 34. The component parts .of the limited lost motion or play connection between the diaphragm 15 and the valve mechanism are so arranged and proportioned that when the diaphragm 15 is flexed by the action of spring 57 to substantially extreme downward position, the flexing force of the cross spring 47 is suflicient to overcome the opening resistance of the outlet valve 35, effecting the snapover action and rapidly moving downwardly the valve 35 to its full open position and simultaneously closing the valve 34. The parts will then be again in the position shown in Fig. II, ready to resume another cycle of operation.

The cycle of operation hereinbefore described will be automatically repeated to gradually build up pressure for the oil transferred by the plunger 68 into the chamber 96 moving the piston downwardly by acting on the upper side in opposition to the progressibly increasing resistance on its other side caused by the compression of the pressurized gas in chamber 97 untilthemaximum predetermined working pressure is established for the oil stored therein, at which time the motive or driving force is insuflicient to perform the working stroke of the plunger 68, so that the pressure generator is stalled or rendered ineffective whereby the conversion unit is inherently regulated without the use of conventional valv- The stalling of the pressure generator takes place when the power or driving force produced by the instantaneous release of the energy stored in the spring 57 is balanced or is insuflicient to force oil into the chamber 96 to further move the piston 95, so that the transfer of oil by the'plunger 68 into the accumulator is inherently stopped. When this condition occurs, the valves 34 and 35 of the pneumatic motor will take the position shown in Fig. II due to the limited or lost play connection between the diaphragm 15 and the .valve mechanism.

It should be noted that whenever the oil stored in the accumulator chamber 96 at a predetermined working pressure is discharged or used as a source of power through the high pressure delivering conduit 109, the cycle of operation will be resumed and the amount of oil discharged from chamber 96 will be automatically replenished as the power conversion unit of the invention is designed to maintain, at all times, an ample supply of hydraulic liquid at a predetermined high-working pressure, providing thereby a hydraulic power system for assisting the driver of an automotive vehicle in the op oration of controlling devices and accessories.

In the embodiment of the invention illustrated in Figs. IX to XII inclusive of the drawings, the principles and general arrangements of the main components of the power unit hereinbefore outlined, used to obtain the conversion of fluctuating sub-atmospheric pressure of low value into substantially constant pressure of high value, are substantially the same as those shown in Figs. I to VIII inclusive. The pneumatic motor operable in response to a source of pressure different than atmosphere, as shown in Fig. IX, is of the reciprocating type having a movable wall in the form of a flexible diaphragm of substantially rectangular shape, clamped at its periphery by the planar bolting flanges of the two rectangularly-shaped, dish-

like members

116 and 117, preferably made of sheet metal which form the motor casing. The member 116 forms with the diaphragm 115, a her- 124. 'for the valve Clearances, and obtain thereby optimum metically sealed chamber 118 carrying on the top 'of'the planar surface .119 the valve block'1'20 mounted in sealed relation thereon by suitable gasket and the screws 121. The planar surface 119 has an enlarged aperture 123 whereby the interior of the chamber 118 is in communication with the annular'suction or air outlet port 124 formed on the bottom surface 125 of the valve block.

The port 124, through the'passage 126 and the connector 113 threaded thereon, is adapted to be connected to an engine intake manifold. The enlarged opening 123 also permits the communication of the chamber 118 with the vertically=directed passageway 127 which leads to the annular atmospheric venting or air inlet port 128 formed on the top surface 129 of the valve block 120.

Fixed to the top surface of member 130 adjacent to itsperforations is a cup-like member 131 of larger diameter having its depending walls terminating adjacent to the perforated flange provided in member 133. The space formed between the cup-like members is filled with suitable sound-deadening material 132, which also acts as an air filter.

The air outlet and inlet ports 124 and 128, provided in the valve block 121 are opened and closed by the automatic valve-actuating mechanism which embodies a pair of planar disc-

like valve members

134 and 135 interconnected by the valve stem 136 passing through the central portion of the valve block 120. The

valves

134 and 135 are alternately seated'or unseated closing the corresponding ports by the movement of the diaphragm 115 through the instrumentality of a snap-over spring arrangement.

As shown in Fig. IX, the

valve members

134 and 135 are so arranged that when the valve member 134 is in open position, the valve member 135 forming an integral part of the stem 136 is seated, closing the air outlet port In order to provide a fine degree of adjustment operation, as well as proper alignment with respect to the valve seat 129, the valve member 134 is threadedly mounted on the valve stem 136 and is adapted to be held in adjusted position by suitable locking means inclusive of a wire passing through the valve stem 136 and castellations formed on the valve member.

The valve stem interconnecting the

valve members

134 and 135 is connected to the diaphragm by a limited lost motion or resilient play connection provided with a spring isnap-over action'in order to insure a rapid and positive seating and unseating of the valve members in proper order and relationship to obtain thereby reliable and trouble-free operation of the motor. This connection and arrangement is substantially the same as the one shown in Fig. VI of the drawings and generally comprises a pair of'U-shaped

members

140 and 141 facing each other and arrangedat substantially right angles, so that their leg'portions are directed in opposite directions. The top member 140 is detachably connected to the threaded end of the valve stem 136 and is capable of adjustment thereon through its central threaded opening and a lock nut 'by the spring performs the snap-over action at the oppo- Site limits of movement of the diaphragm 115 for simulita-neeusly ch'ari'ging'the position of the vaivesls sand 135.

The u standing :U-shaped member 141 is fixed to the "diaphragm by riveting the same ontop of the diaphragm 'reinfor'cingplate 152 through the upsetting of the end of the reduced shouldered portion 153 of the motor work-performing or output member 154. The reduced portion 153 projects through central openings :iprov'ided in the diaphragm 115 and reinforcing

plates

152 and 156 and its shoulder abuts the lower surface of plate 1'56,'providing arigid connection between the diaphragm 115 and output member 154, as well as means to hold the same in hired and leak-proof relation.

In the form of the invention shown in Fig. IX, the outputmember 154 of the pneumatic motor is urged to its work-performing position by distortable resilient means supporting bracket 158 which, in'turn, is fixedly secured to the stationary casing member 117 and is located in position by an upwardly-projecting flange 159 which projects throughxthe central aperture of the casing member.

The power spring 157, housed within the tubular section -of'the bracket .158, hasits lower end in engagement with a=horiiontally-disposedflange 160 of the cup-like retainer .161, which is connected to the output member 154 through its detachable wrist pin 162, so that the diaphragm 115, and thereby its output member 154, are resiliently biased to one position. The spring retainer 161 includes the same constructional details shown in Fig. VII, and is arranged to provide a type of bayonet connection with the wrist pin 162, as particularly shown in Figs. VII and VIII, so that its rapid assembly and disassembly can be eifectively accomplished;

The hydraulic pressure generator or pumping unit of the invention is driven by the pneumatic motor through 'auniversal-ball and socket power-transmitting connection .which'interconnects the motor and generator in axial alignment. This connection is shown in the form of a socket 165 formed at the end of member 154 which re tains the ball-shaped section 167 formed at the "end of the cylindrical plunger. 168 which constitutes the reciprocable piston means of the hydraulic pressure generator .unit.

In the modified form of theinvention the piston '168 of ,the pressure-generator is reciprocable in the central bore 169 .of the hydraulic pump body forming a cylinder therefor which, in this embodiment, is made in three sections forea'se of manufacture and ready assembly. The sections 170, 171,2and 172 are provided with planar mating surfaces adapted to be clamped together, forming a liquid-tight assembly, by suitable means,such as threaded bolts -173, which' also .act as means to secure the 'pump body to the lower flange 174 of the pump bracket 158 through the clamping ring 175 having threaded engage- .mentwith the clamping bolts 173.

' The central bore-169 constituting the liquid-receiving chamber is .formed'on the top section and is provided .a'tits upper end withs'ealing means 176 whereby the piston 168. is in liquid-tight relation during its reciprocatory movement. The planar surface. of section170I-forming the lower end of the chamber 169 is provided with an enlarged circular recess 177 which accommodates and permits the movement of the reciprocable light-weight annular valve 178 of thin material provided with upstanding lugs 178,(see Figs. XI and XII). The valve member 178 is operable in response to the motion of the piston 1'68 toperrnit the entrance of liquid into the cyl- -'indei' chamber 169'when the piston is retracted and closed during its pumping stroke by being seated against the assaam top planar surface of the intermediate section 171 which is provided with an annular groove forming the inlet port 179 leading by a passage 179' to the enlarged annular passageway 180, uponwhich is fixedly retained the filtering screen 181.

The opening 182 of the annular valve 178 is in alignment with the chamber 169 and with the discharge passage 183 traversing section 171 which is adapted to be closed by the ball member 184 urged against its valve seat by spring 185 reacting against the annular member 186 held in sealed relation between the planar mating surfaces of sections 171 and 172 by'suitable sealing means such as an O-ring 187.

The pump discharge passage 183 is intercepted below the valve member 184 by a passage 188, to which is connected in fluid-tight relation the lower end of a conduit 189 leading to the connector 190 fixed on top of the casing member 116, constituting the high pressure delivering means of the power conversion unit. The'bot tom section 172 of the pump body has a central aperture, to which is brazed the tubular member 191 forming the high pressure discharge passage which connects the pump to the accumulator.

The cup-like member 192, preferably made of sheet metal, is secured by its top section to the bolting flanges of the pneumatic motor casing, and forms a container adapted to retain at atmospheric pressure a supply of hydraulic liquid, surrounding the pumping mechanism. The container 192 is fixedly secured by its bottom. planar section 193 through a suitable sealing gasket 193 and bolts 194 to the upper end head of the pressurized accumulator.

In the embodiment illustratedin Fig. IX, the accumulator used to establish the working pressure for the hydraulic liquid in order to provide a substantially constant power source for a hydraulic power supply system having a working pressure of approximately 1,000 p. s. i. or higher if desired is of the type in which a movable piston is permanently biased to one position by cushioning means housed therein, such as compressible fluid held under a predetermined pressure. The accumulator shown comprises a movable member or piston 195, by means'of which its interior is divided into two opposed compartments wherein the compartment 196 constitutes the liquidstoring chamber, and compartment 197, a compressible space adapted to permanently hold or be charged asrequired preferably with a dry inert gas, by means of a one-way valve 198 carried by its casing. The accumulator casing comprises an outer tubular member 200 made preferably of an ordinary piece of steel tubing closed at both ends by curved pressure-resisting end heads having a relatively concave curvature, each formed by similarly arranged members. I i

The pressure-resisting end head which hermetically closes the lower end of the steel tube 200 comprises a planar circular member having a peripheral offset forming a flanged closure 20 1 brazed at 203 to the innerpea riphery of the annular member 204 of spherical configuration. The outer periphery of member 204 has press-fitting engagement with the shoulder section 205 formed at the inner surface of the tube 200 and is joined thereto by a continuous annular weld 206. It should be noted that the closure member 201, as hereinbefore mentioned, has at its central portion a valve 198 which provides one-way communication with the casing interior for the purpose of charging the accumulator with a compressible gas.

The pressure-resisting head, which hermetically closes the upper end of the steel tube 200, comprises a planar circular member having a peripheral offset forming a flanged closure 207 brazed at 208 to the inner periphery of the annular member 209 of spherical configuration. The other periphery of member 209 is arranged and dimensioned to provide a press-fitting engagementwith the shoulder section 210 formed at the inner surface of the 12 tube 200 and is joined thereto by a continuous weld 212. The closure 207 has a central aperture 213 in alignment with openings formed on the planar surface 193 and on the sealing gasket 193' for receiving in leakproof relation the high pressure discharge conduit 191 of the pump unit. The conduit 191 is appropriately sealed in aperture 213 by high pressure sealing means comprising an annular member 214 which retains in suitable relation the 0-ring 215.

The depending boss or flange section 216 of the closure 207 is encircled by the cylindrical member 217 closing the same in sealed relation by means of an Daring 218 retained in the rectangular groove 219 and its bottom surface is recessed forming a reduced planar outer section 220 so as to substantially avoid the possibility of piston 19S sticking thereto in case of a complete discharge of the liquid normally retainedin chamber 196.

The movable piston 195 of the accumulator unit is provided at its upper surface with a central recess 221 to limit the area of engagement with the bottom surface of the closure 207 to' avoid the possibility of sticking thereon, and is provided with suitable sealing means to prevent leakage or interconnection between the oil-storing compartment 196 and the compressible cushioning space 197 separated by the piston. The sealing means shown comprises an O-ring 222 located in a rectangularlyshaped groove 223 formed on the depending cylindrical wall section 224 of the piston which has a sliding fit with the inner surface of the cylindrical member 217 which has a working fit at its lower end with the flange 225 of the closure 203. The cylindrical member 217 is provided with a plurality of openings 126 located slightly above the top surface of the flange 225, so that the space below the piston member is in communication with the annular space surrounding the same whereby the pressurized compressible gas surrounds the liquid-storing 'chamber.

As particularly shown in Fig. X, the top surface of the motor casing member 116 is provided with a connector 227 whereby the liquid under pressure delivered by the pressure unit is returned to the container 192, within which is retained at atmospheric pressure, the supply of hydraulic liquid. The casing member 116 is also provided with an aperture for filling the container 192 with the hydraulic liquid at a predetermined level, and is closed by a perforated cap 228 provided with a level stick 229, by means of which the level of the liquid surrounding the pumping mechanism can be readily ascertained. The conversion unit of the invention is adapted to be supported in any desirable position within the engine compartment or within the frame-work of the automotive vehicle and, for purpose of illustration, the same is provided with suitable supporting means, which, in the modified form of the invention, is shown as a bracket 230 fixedly secured to the outer member 200 of the accumulator unit.

The operation of the modified form of the invention is the same as that already described with respect to the form shown in Figs. I to VIII inclusive. It should be observed, however, that in Fig. IX, the parts are shown in the position which they occupy in the cycle of operation prior to the release of the stored power to effect the pumping stroke of the piston for transferring the hydraulic liquid into the pressurized accumulator.

It should be noted that in both embodiments of the invention a self-integrated unit having numerous parts of the three component units are arranged to serve dual purposes whereby the cost of manufacture is greatly reduced. Moreover, the three main components of the conversion unit form unitary subassemblies suitable for independent calibration and which can be easily and quickly assembled and disassembled for inspection and substitution, as well as for service and replacement in the field Without the use of special tools or complex equipment.

It is to be understood that the above detailed description of the present invention is intended to disclose an embodiment thereof to those skilled in the art, but that the invention is not to be construed as limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being practiced and carried out in various ways without departing from the spirit of the invention. The language used in the specification relating to the operation and function of the elements of the invention is employed for purposes of description and not of limitation, and it is not intended to limit the scope of the following claims beyond the requirements of the prior art.

What is claimed is:

1. In combination, a cylinder, a reciprocating piston movable in said cylinder, a reservoir retaining a liquid surrounding said cylinder, a valve means on a wall of said cylinder open for the entrance of liquid from said reservoir when the piston is moved in one direction and closed upon the discharge of the liquid from said cylinder in response to the movement of the piston in a different direction, a pressurized accumulator of the piston type carried by said reservoir operatively connected to said cylinder including valve means in said connection for establishing a predetermined working super-atmospheric pressure of high intensity for the liquid discharged from said cylinder into said pressurized accumulator, and a diaphragm motor also carried by said reservoir operable by engine manifold vacuum including resilient means operatively connected to said reciprocating piston for moving the same in its discharge stroke to thereby effect the conversion of variable sub-atmospheric pressure into hydraulic super-atmospheric pressure of high intensity.

2. In combination, a pressurized accumulator, means for forcing liquid from a source thereof into the pressurized accumulator to establish a predetermined high working pressure for the liquid forced in said accumulator, a reciprocating piston and a cylinder therefor forming a part of said liquid-forcing means, valve means on the wall of said cylinder open to effect entrance of liquid from said source when the piston is moved in a retracting direction and closed in response to the other direction constituting the pumping stroke of the piston, the said pressurized accumulator having a valve means connected to said forcing means and a piston biased to one position by a compressible fluid, a casing surrounding said forcing means acting as a liquid container therefor and supporting at one end said pressurized accumulator, a subatmospheric fluid pressure reciprocating diaphragm motor carried at the other end of said casing, said diaphragm motor including yielding means for operating said forcing means, and the said diaphragm motor operated by engine manifold vacuum to thereby effect the transfer of a low intensity variable sub-atmospheric fluid pressure into hydraulic pressure of high value.

3. In combination, a pressurized accumulator for storing a liquid under pressure, a movable piston in said accumulator dividing the same into opposed chambers urged to one position by bias means housed therein, a pump cylinder, a reciprocating piston in said cylinder, a liquid-retaining reservoir surrounding said cylinder and supporting at one end said pressurized accumulator, a single valve member carried by said pump cylinder, said single valve member responsive to the movement of said piston by being moved to open position for effecting admission of liquid from said liquid-retaining reservoir into said cylinder and being moved to closed position to stop the admission of said liquid during the pumping movement of the piston, conduit means including valve means directly connecting the discharge of said cylinder to said accumulator providing a liquid connection therebetween for effecting the direct transfer and storage of the liquid pumped by said piston into said pressurized accumulator against the force of said bias means to establish thereby a relatively high working pressure for the liquid stored in said pressurized accumulator, and a diaphragm motor also carried by said reservoir operable by engine manifold vacuum including resilient means operatively connected to said reciprocating piston for moving the same in its discharge stroke to thereby effect the conversion of variable sub-atmospheric pressure into hydraulic superatmospheric pressure of high intensity.

4. In combination, a pneumatically operated diaphragm motor having an output member axially disposed, yielding means operatively connected to said output member, a hydraulic pump having a reciprocating piston operated by the output member of said diaphragm and being positioned in axial alignment therewith, a pressurized accumulator having a piston biased to one position by compressible fluid positioned in axial alignment with said reciprocating piston, the said pneumatically operated motor operated by an engine manifold vacuum to store mechanical power in said yielding means when the piston and output member are moved in response to the application of vacuum in a retractingdirection and to release the stored mechanical power when the application of the engine manifold vacuum is stopped to thereby effeet the transfer of a low intensity variable sub-atmospheric fluid pressure into hydraulic pressure of high value, and a casing surrounding said hydraulic pump and performing the function of supporting at opposite ends the pneumatically operated motor and the accumulator,

also maintaining the axial alignment of the motor and accumulator, as well as acting as a container for retaining at atmospheric pressure a supply of liquid surrounding said hydraulic pump.

5. In combination, a pressurized accumulator comprising an enclosing shell and a movable piston dividing the space within said shell into a liquid-storing space and a cushioning space, a pump mechanism having a reciprocating piston operable to draw liquid from a supply, a single valve member carried by said pump cylinder adjacent its discharge end, said single valve member responsive to said piston by being moved to open position for effecting admission of liquid from a source of supply into said cylinder and being moved to closed position to stop the admission of said liquid during the discharge movement of the piston, a conduit connecting said pumping mechanism and accumulator to effect the transferring of the liquid in the pump mechanism to the storing space of said accumulator, yielding driving means connected to said pump mechanism providing a predetermined force for effecting the discharge stroke of said pump to transfer of said liquid by said pump mechanism, said yielding means rendered inelT-ective to effect the discharge stroke of said pump mechanism when the pressure in the cushioning space of said accumulator reaches a predetermined maximum, valve means in said conduit operable to inhibit the reverse flow of liquid therethrough, a diaphragm motor operable by engine manifold vacuum to store mechanical power in said yielding means when the piston is moved in response to the application of vacuum in a retracting direction and to release the stored mechanical power when the application of engine manifold vacuum is stopped to thereby effect the transfer of low intensity variable sub-atmospheric fluid pressure into hydraulic pressure of high value, and a casing supporting in axial alignment the said diaphragm motor and accumulator and acting as a container for retaining a supply of liquid surrounding said pump mechanism.

References Cited in the file of this patent UNITED STATES PATENTS 1,390,617 Jay Sept. 13, 1921 1,825,411 Murphy Sept. 29, 1931 2,301,916 Horton et al Nov. 17, 1942 2,605,716 Huber Aug. 5, 1952 FOREIGN PATENTS 955,153 France Ian. 6, 1950