US3041975A

US3041975A - Fluid actuated hydraulic power unit

Info

Publication number: US3041975A
Application number: US31919A
Authority: US
Inventors: Neil F Atherton; Joseph L Johnston
Original assignee: Applied Power Industries Inc
Current assignee: Enerpac Tool Group Corp
Priority date: 1960-05-26
Filing date: 1960-05-26
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03
Also published as: GB917699A

Description

y 1962 N. F. ATHERTON ETAL 3,041,975

FLUID ACTUATED HYDRAULIC POWER UNIT Filed May 26, 1.960 4 Sheets-Sheet 1 INVENTORS NE. F. Grazer-av dOJEP/i .4. JdHNJfan/ BY MMJM y 1952 N. F. ATHERTON ETA]. 3,04l ,975

FLUID ACTUATED HYDRAULIC POWER UNIT Filed May 26, 1960 4 Sheets-Sheet 5 B M We; m

A 7 QEMEY} July 3, 1962 N. F. ATHERTON ETAL 3,041,975

FLUID ACTUATED HYDRAULIC POWER UNIT Filed May 26. 1960 4 Sheets-Sheet 4 I N V EN TORS N514, F. 977452 7-0 JOSEPH A. Jay/15f mmemeeu.

United atent fiic 3 041,975 FLUID ACTUATED I IYDRAULIC POWER UNIT Neil F. Atherton, Bayside, and Joseph L. Johnston, Hartland, Wis., assignors to Applied Power Industries, Inc., a corporation of Wisconsin Filed May 26, 1960, Ser. No. 31,919 15 Claims. (Cl. HIS-5G) The present invention relates generally to improvements in hydraulic pressure applying tools adapted to perform diverse work, and relates more particularly to improvements in the means for actuating such tools.

A primary object of our invention is to provide an improved fluid actuated hydraulic power device which is of extremely compact and unitary construction and which is moreover highly eflicient in operation as well as flexible in its adaptations.

In many types of industries, vehicle service garages, rescue work, salvaging operations and the like, it is frequently required or exceedingly advantageous to utilize hydraulic power devices capable of delivering high pressure fluid to perform certain work. It has become common practice in such instances to use hydraulic pumps for delivering high pressure fluid to such tools as rams used for straightening, bending, raising, and other operations, load lifting jacks of various types, power presses, power shears, load handling cranes and similar devices.

For the most part, these hydraulic pumps are manually operable. However, it has been heretofore proposed to operate the same by electric motor as well as by air motor. Manual operation is, of course, tedious and fatiguing as Well as time-consuming, and frequently, the operator experiences difliculty in manipulating the pump in relatively inaccessible locations. On the other hand, electric operation is costly and relatively hazardous, requiring a suitable motor together with its driving connections and involving the use of electric current. Furthermore, electrically actuated hydraulic pumps are necessarily bulky and difficult to handle, thus restricting their use. As for the air powered hydraulic pumps heretofore proposed, these have failed to gain widespread commercial acceptance for vairous reasons such as bulkiness, relatively high cost, lack of durability, inefficiency in operation and stoppage resulting from clogging or blocking of ports and passageways, failure to operate continuously under varying conditions and in all positions, failure to provide efficient and convenient manipulating and control mechanism for the air throttle valve and the hydraulic circuitry, high maintenance cost, and improper location of such elements as the high pressure outlet, throttle, reservoir, hydraulic passages, and the like.

It is therefore a further object of this invention to provide an improved hydraulic pump or power unit operable by pressurized fluid and which obviates or minimizes the above described disadvantages and objections attendant prior devices of this general type.

Another important object of the invention is to provide an improved light weight and portable pneumatically actuated hydraulic power package of exceedingly compact, unitary and durable construction adapted to be produced at low cost, and in which the major components such as the fluid motor, the hydraulic pump, the air inlet port, and the high pressure hydraulic outlet, are all in axial alinement with the air and hydraulic circuitry lying in different radial planes relative to each other and transversely of the main central axis of the tool.

A further object of our invention is to provide an improved hydraulic pump powered by pressurized fluid and which is readily manipulatable in confined areas and in any position by hand, foot or other means, and which has but a single operating lever sensitive to the touch and swingable in a single place for controlling both the throttle valve for pressurized fluid such as live air as well as the hydraulic circuitry through a novel pressure release valve in a positive manner.

Still another object of our present invention is to provide an improved and highly eflicient fluid actuated hydraulic power unit which is effectively sealed and operable under varying atmospheric conditions or even when completely submersed in liquid or used in dust laden surroundings and which may be readily adapted for remote control as well as for direct attachment to hydraulic cylinders or the like.

An additional object of the present invention is to provide an improved air atctuated hydraulic pump device which embodies extremely efficient, simple and highly accurate valving arrangements whereby exceptionally smooth and positive operation is obtained and in which the components are readily replaceable, the pump also incorporating a novel oil reservoir which permits complete and effective utilization of the liquid stored therein while offering maximum heat exchange surface for the liquid.

Another object of the invention is to provide an improved fluid operated hydraulic device adapted to effectively operate over a wide range of airline pressure without adverse effects from normal variations in line pressure and without need for a separate pressure regulator, the air motor of the device embodying a simple and highly effective self-cleaning air-floated single spool valve having a shear seal cutoff for distributing pressurized fluid and controlling the operation.

These and other objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings wherein like reference characters designate the same or similar parts in the several views.

FIG. 1 is a perspective view of a typical powered hydraulic pressure applying unit embodying the invention;

FIG. 2 is an end view of the device looking at the rear or throttle end thereof, part of the exhaust air check valve being broken away to reveal normally concealed structure;

FIG. 3 is a longitudinal vertical section through the assemblage showing the air motor piston positioned at the end of its forward stroke and about to begin its return stroke, the oil reservoir being shown in capacity or near capacity condition by means of full lines and in near empty condition by means of dotted lines;

FIG. 4 is a longitudinal horizontal section through the unit but with the air motor section being projected along the off-center line 44 of FIG. 2 to more clearly illustrate the sealed air byepass from the piston chamber to the air exhaust ports, the air motor piston in this view beingshown in its rearmost position about to begin its forward stroke;

FIG. 5 is a transverse vertical section through the hydraulic valve block taken along the line 55 of FIG. 3;

FIG. 6 is a transverse vertical section through the air valve block taken along the line 6-6 of FIG. 3, the section being projected through the reduced portion of the spool valve;

FIG. 7 is an enlarged fragmentary section through the pressure release valve portion of the hydraulic valve block taken from FIG. 4 and showing the valve in seated condition;

FIG. 8 is a similarly enlarged fragmentary section through the release valve showing the valve in open pressure release condition;

FIG. 9 is a somewhat reduced top view of the device showing a ram cylinder in section attached directly to the high pressure discharge end with a suitable adapter secured to the opposite end thereof; and

FIG. is a schematic diagram illustrating the major components and the air and hydraulic circuitry.

Referring to the drawings, the power unit shown therein as embodying the invention comprises, in general, a unitary body 16 mounted on a suitable base 11 and having an actuating lever 12 pivoted thereon. The body 16 contains a fluid motor portion 13 closed at one end by a valve block 1 for the fluid motor portion and having a hydraulic portion 15 extending from its opposite end with a hydraulic valve block 16 interposed therebetween. Live air or other pressurized fluid from a suitable source is admitted by means of the inlet line 17 to the motor portion 13 of the device, and high pressure hydraulic fluid is discharged from the hydraulic portion 15 by way of a high pressure discharge line 18. The body it) is conveniently of cylindrical shape, and the fluid motor portion 13, hydraulic portion 15, and both valve blocks 14 and 16 as well as the pressurized fluid inlet line 1'7 and high pressure discharge line 13 are all in axial alinement.

Referring first to the motor portion 13 as shown herein, a supply hose 17 may be connected to the air valve block 14 as by means of a threaded coupling 26 and supplies pressurized fluid such as compressed air from a suitable source to a

supply passage

21, 22 formed in the block 14. The

supply passage

21, 22 has a cylindrical throttle chamber 23 formed therein which is closed by a threaded plug or bushing 24 housing the throttle valve 25. The throttle valve 25 is slidably fitted within the plug 24 and projects upwardly through the plug and above the valve block 14-. The valve 25 has a lower collar or flange 26 which is normally seated against the lower end of the plug 24 by the action of a spring 27 compressed between the bottom of an outwardly open recess 23 formed in the plug and a washer 29 or similar flange forming member held captive on the projecting end of the valve stem as by means of a pin 36 or the like. The plug 24 has ports 31 in open communication with the air supply passageway 21 above the valve seat and the collar 26, and the valve stem is provided with an annular flange 32 and a suitable seal 33 located above the supply ports 31. The throttle valve is therefore removable in its entirety with the plug 24- for ready inspection, replacement or repair, and is actuated upon downward movement of the upwardly projecting stem portion in opposition to the action of spring 27 as will hereinafter more fully appear.

The air valve block 14 is also formed with an axial bore 35 extending therethrough and closed at its outer enlarged end by a closure plug 36. Housed within the bore 35 is an air servo spool type valve 37 having intermediate portions 38, 39 of reduced diameter and an end portion 40 of increased diameter confined Within the enlarged outer end of the bore 35. The spool valve 37 is reciprocable within the bore 35, being limited in its movement by the enlarged end head 40 operating in the similarly enlarged portion of the bore. The inner face of the valve block 14 is provided with a recess 41 surrounding the bore 35 and communicating directly with one or more exhaust passages 42 formed in the air valve block 14, the recess 41 being closed by a plate 43 having a port 44.- therein alined with and of the same diameter as the bore 35. The spool valve 37 is also provided with a passageway 45 extending between the reduced diameter portion 38 and the inner end thereof which has a pilot portion extending into the air motor chamber 46 to be hereafter more fully described. Accordingly, in the rearward position of the spool valve 37, the air supply passage 22 is in communication with the motor chamber 46 through the reduced diameter portion 38 and the passageway 45 with the recess 41 being closed from the motor chamber 46 by the plate 43 and the adjacent end of the valve, while in the forward position of the spool valve 37, the recess 41 and exhaust passage '42 is open to the motor chamber 46 through the reduced diameter portion 39 with the supply passage 22 being closed by the valve. Thus, the spool valve provides for alternate supply and exhaust porting of the adjacent end of the motor chamber, and the valve 37 is conveniently accessible upon removal of the plug 36.

The air motor displacement chamber 46 has a large diameter piston 48 reciprocable therein, the motor chamber being vented to exhaust as at 49 remote from the air valve block 14. Seated against the front face of the air motor piston 48 is a small diameter pump piston 50 operable to pump hydraulic fluid through passages formed in the hydraulic block 16 as will hereinafter more fully appear. The rear of the pump piston 50 extends into the motor chamber 46 and is preferably formed with a somewhat enlarged end head 51 having a rounded or spherical bearing surface constantly urged to seated position against the face of the motor piston 48 by a spring 52 compressed between and seated against the rear of the hydraulic valve block 16 and an annular flange 53 radiating from and held captive on the pump piston 50 adjacent its end head 51. The wall of the motor chamber 46 is also provided with a port 54 adapted to be uncovered by the motor piston 48 only when the piston reaches the end of its forward stroke to thereby place the rear portion of the motor chamber, via passages 55, 56, in communication with the cavity 57 formed by the enlarged portion of the bore 35 in back of the enlargement 46 of the spool valve 37. Thus, assuming the spool valve 37 is positioned as in FIG. 4 with the small diameter portion 38 adjacent the air supply passage 22, pressurized air is admitted to the motor chamber 46 behind the piston 48 by way of the passageway 45 in the spool valve to thereby move the piston forwardly or to the left in the motor chamber. When the piston 48 reaches or approaches the end of its forward stroke, the port 54 is uncovered to admit pressurized air from the rear of the motor chamber 46 to the cavity 57 by way of passageways 55, 56, the air thus admitted to the cavity 57 thereupon acting on the rear face of the portion 40 of the spool valve 37 to move this valve forwardly or to the left as shown in FIG. 3. The spool valve in this position cuts off communication between the air supply line 22 and the motor chamber 46 and opens the motor chamber to exhaust through the port 44, recess 41 and exhaust passage 42, thereby permitting re turn of the motor piston 48 as well as the pump piston 56 by the action of the spring 52. As the motor piston is returned to its starting position, the rear face thereof contacts the projecting end of the spool valve 37 and moves the same to its initial position whereupon the above described cycle is repeated.

The pump piston 50 is thus reciprocable within its displacement chamber 59 by the combined action of the air motor piston 48 and return spring 52, and while the pump displacement chamber 59 may be formed directly in the hydraulic valve block 16, it is preferably formed as shown in a readily removable and replaceable cartridge 6% which is threadably received in the block 16. The removable cartridge is provided with a threaded cap 61 at its outer rear end which prom'des a retainer for a suitable seal or packing 62 embracing the pump piston, and the inner end of the cartridge has fingers 63 providing a retainer and spacer for the pump inlet check valve 64- on the suction stroke of the piston 50. The hydraulic circuitry is all formed in the hydraulic valve block 16 and comprises, in part, a suction or supply passage 65, including one or more branches 66, extending from the hydraulic reservoir 67 formed in the hydraulic portion 15 past the ball check valve 64 to the pump displacement or pressure chamber 59, the ball valve 64 being seated in an obvious manner to close the passage 65 during the forward pumping stroke of the piston 50 and being unseated to open the passage 65 during the return or suction stroke of the pump piston. Also formed in the valve block 16 is the pump discharge or exhaust port 68 communicating with the high pressure discharge passageway 69 past a one-way ball check valve 70, the passageway 69' in turn communicating directly with a conduit 71 extending axially through the center of the reservoir 67 formed in the hydraulic portion and into communication with the flexible discharge line 18.

The oil in the reservoir 67 is confined within a unique container or sack formed by a flexible membrane 73 of generally cylindrical shape having one end reversed inwardly and secured to the high pressure discharge conduit in a suitable manner as by a split ring 74, the other end of the container being held captive between the wall of the section 15 and the periphery of the hydraulic valve block 16 as by means of an annular groove 76 receiving a bead 75 formed on the membrane. Since it is necessary to vent the reservoir chamber to atmosphere as at 77, the hydraulic fluid confined within the sack 73 is thus sealed and protected from ingress of foreign matter. Furthermore, the construction and attachment of the membrane or sack as shown and described insures collapse, thereof, as oil is withdrawn, progressively from the end remote from the valve block 16 toward this block, thus permitting complete utilization of the reserve fluid by virtue of the fact that the membrane does not collapse over and cover the hydraulic passages formed in the block 16. However, to doubly insure against possible interference of the membrane 73 with the hydraulic circuitry, the adjacent face of the valve block may be formed with an annular groove or recess 78 into which the hydraulic passageways are directed. To permit access to the interior of the oil-containing sack for refilling and like purposes, a suitable passageway 79 is formed in the hydraulic valve block 16, and this access or fill passage is normally closed by a threaded plug 80.

As previously indicated, the throttle valve 25 is actuated upon downward movement thereof, and for this purpose, the lever 12 is provided. While the design of this actuating lever 12 may, of course, be varied within the scope of the invention, it is preferred to pivotally mount or support the same on a medial portion of the device by means of horizontal pivot or fulcrum pins 82, 83- threadably received in opposite sides of the hydraulic valve block 16. In its preferred form, the lever is of integral one-piece construction and has a treadle portion 84 extending rearwardly above and beyond the upwardly projecting stem of the throttle valve 25 to cover the same while permitting actuation thereof upon downward application of pressure by foot or hand to the treadle portion 84. The lever 12 is also preferably formed with forwardly and upwardly directed side arms 85 spanned at the outer or forward end by a cross-piece 8 6 which not only provides a convenient carrying handle for the device but also forms a forwardly extending treadle portion for swinging the lever in the opposite pressure release direction as will hereinafter more fully appear. While unnecessary for proper functioning of the actuating lever, means such as a tension spring 87 secured between the lever and the air portion 13 of the body to constantly urge the treadle portion 84 of the lever toward seated position against the throttle 25 is also provided, and the primary purpose of this spring is to return the lever to a neutral position.

The means for urging the hydraulic discharge ball check valve 70 to seated position is conveniently housed within a recess 89 formed in the lever pivot or trunnion 82 and consists of a spring 90 seated and compressed between the base of the recess 89 and the rear face of a disk 91 having a projecting finger coacting with the ball 70. One leg 92 of the bifurcated lever 12 is preferably loosely rotatably received by the enlarged head of the pin 82 which may be formed with a tool receiving slot as shown for ready removal of the pin when it is desired to either remove the lever or obtain access to the ball check 70.

To release the pressure developed in the high pressure hydraulic discharge conduit 71 and line 18 upon completion of the desired work, novel release valve mechanism for porting the conduit 71 back to the hydraulic reservoir by way of

release passageways

94, 95 also formed in the hydraulic valve block 16 has been provided. This pressure release mechanism consists generally of a threaded plug or bushing 96' removably received Within a bore 93 formed in the valve block 16 concentrically with the pivot for the lever 12, the plug 96 having a passageway 97 formed therein and communicating with the

release passages

94, 95 past a ball valve 98. The ball check valve 98 is normally seated against the passage 97 at the inner end of the plug 96 by action of the pressure fluid in line 94, and with the device operating to pump hydraulic fluid to the desired source, the release valve is therefore closed. The lever pivot pin 83 is partially threaded within an outwardly open recess 99 formed in the plug 96 to permit free rotation thereof relative to the plug, and this pin 83- is further provided with an inwardly projecting finger 100 of reduced diameter extending freely into the passage 97 in close proximity to the ball valve 98. In its normal inoperative position, the finger is therefore withdrawn from and does not interfere with the action of the ball check 98, but upon rotation of the pin 83 in a clockwise direction, its screw threads cause the pin 83 to move axially inwardly thus projecting the finger 100 against the ball 98 to unseat the same against the pressure built up in the passage 94. To facilitate this release operation, the hub on the bifurcated lever arm 101 is split radially as at 102 (FIG. 5) and is provided with a clamp screw 103 so that the head of the pin 83 may be firmly clamped in the lever arm 101 for rotational movement therewith. Accordingly, when treadle 84 of the lever 12 is swung downwardly to actuate the throttle valve 25, the pin 83 with its finger 100 is backed away from the ball 98 which automatically seats to close the release passage 97 by action of the pressure fluid in passage 94. To release the pressure built up in the passage 94, it is only necessary to swing the lever 12 in an opposite direction beyond its neutral position by means of the treadle portion 86 thereof whereupon the pin 83 is rotated to project the finger 100 thereof against the ball 98 to unseat the same and open the passage 94 through

passages

95, 97 to reservoir. The pin 83 may also be conveniently provided with a tool receiving slot for ready access and removal, and a suitable seal 104 may also be provided above the passageway 93 so as to prevent seepage of hydraulic fluid past this pin.

When it is desired to seal the air motor for effective operation inexceptionally heavy dust laden surroundings or even under water as in salvage work, the exhaust ports 42 in the air valve block 14 may be covered by a flexible cap 106 secured in position as by a screw 107 or the like. The cap 106 thus, in effect, provides a flap valve permitting escape of exhaust air from the passageways 4-2 to atmosphere while preventing entrance of air, Water or foreign matter, and the forward end of the air motor chamber 46 may likewise be sealed by providing a suitable by pass from the vent 49 to the exhaust passage 42. As shown in FIG. 4, this may be readily accomplished by forming a passageway 108 communicating with one of the exhaust ports '42 in the air valve block 14 and by placing the vent 49 in closed communication with the passage 108 as by means of a conduit forming member 109 secured as by a screw 1.10 to the valve block 14 or some other convenient part of the body.

The various parts of the improved air actuated hydraulic pressure applying tool may be readily fabricated and assembled with the cylinder wall of the fluid motor portion 13 being conveniently attached to the motor valve block 14 and the hydraulic valve block 16 as by means of pins and/ or screws 112 and 113 respectively. The device may obviously be readily dismantled for inspection or repair of all working parts, and the base may be secured to the body as by screws 115. The lever 12 may likewise be quickly and easily removed in an obvious manner, and the throttle valve 25 may be removed bodily with the plug 24 upon rotation of the lever counterclockwise for access thereto. Similarly, the hydraulic pump which is entirely contained within the cartridge 60 may be bodily removed and replaced upon dismantling of the motor portion, and access to the air pilot valve 37 may be obtained merely upon removal of the closure plug 36. Access to the ball check valve 70 may also be obtained merely upon removal of the pin or trunnion 82., and the release valve is also self-contained in a readily removable plug or cartridge 96. The supply of reservoir fluid may be replenished if and when necessary merely by removal of the plug 80, but access to the reservoir may be obtained upon removal of the end cover plate 81, the cover plate being suitably held in position by means of a nut 114 threaded to the outwardly extending end of the high pressure discharge conduit 71. The device may, of course, be provided with suitable gaskets and seals, which have not been described in detail, without departing from the spirit of the invention.

The flexibility of the device in its adaptations is believed apparent from the foregoing description, and as shown in FIG. 9, a hydraulic ram may be readily applied directly to one end of the tool and a suitable adaptor to the opposite end, the ram cylinder 117 being screwed directly to the end of the high pressure discharge conduit 71 and the adaptor 118 being attached to the valve block 14 by means of screws 119 or the like to provide spacing and attachment means. Obviously, high pressure hydraulic fluid developed by the tool is thus conducted to the interior of the cylinder 117 and causes outward movement of the ram 120 to perform the desired work.

By means of the fact that all of the major components are axially alined with the hydraulic and pressurized fluid circuitry formed in the respective valve blocks radiating from the main central axis of the device, manufacture of the improved unit is facilitated and operation is simplified by use of a single control lever. In this connection, it is noteworthy that the various air and hydraulic flow passages may be readily formed by simple machining operations with all valves being easily accessible. Also, since the axis of the throttle valve and that of the hydraulic release valve lie in different radial planes relative to each other with both of these axes being perpendicular to the major axis as illustrated diagrammatically in FIG. 10, a simple readilly operable lever for controlling both the air and hydraulic circuitry and adaptable for remote control may be provided.

The motor piston is freely slidable within the motor chamber and has but a single bearing point contact on the rounded head 51 of the pump piston so that side thrusts and the like are eliminated. In addition, the fluid motor is controlled by a single freely slidable spool valve 37 directly responsive to the action of the motor piston 48 in one direction and responsive to pressure of fluid exhausted from the motor chamber 46 for its movement in the opposite direction, and such control valve structure is extremely simple and positive in its action with the flow ports and passages being constantly kept clean and free of contaminents.

While the structure of the improved device has been shown and described herein in considerable detail, it is not intended to thereby unnecessarily restrict the invention since various modifications within the scope of the appended claims may occur to persons skilled in the art to which the invention pertains.

We claim:

1. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed in one end and a hydraulic reservoir in the other end axially alined with said motor chamber, a motor piston reciprocable within said chamber, a motor valve block closing the end of said motor chamber remote from said reservoir, said motor valve block including inlet and exhaust passages,

a hydraulic valve block interposed between said motor chamber and said reservoir, said hydraulic valve block including a pumping chamber opening to one side thereof and hydraulic inlet and discharge passages, a piston reciprocable in said pumping chamber and having a portion coacting with said motor piston, and a tubular member secured at one end to the opposite side of said hydraulic valve block and extending through said hydraulic reservoir and out the adjacent end of said body, said hydraulic discharge passage communicating between said pumping chamber and said tubular member to thereby form an axially extending hydraulic discharge passageway.

2. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed in one end and a hydraulic reservoir in the other end axially alined with said motor chamber, a motor piston reciprocable within said chamber, a motor valve block closing the end of said motor chamber remote from said reservoir, said motor valve block including inlet and exhaust passages, and a throttle valve, a hydraulic valve block interposed between said motor chamber and said reservoir, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and discharge passages, a piston recipr-ocable in said pumping chamber and having a portion extending into said motor chamber for coaction with said motor piston, tubular member forming a high pressure hydraulic discharge passageway extending axially from the discharge passage formed in said hydraulic valve block through said hydraulic reservoir and out the adjacent end of said body, and a generally U-shaped actuating lever having its legs swingably mounted on said hydraulic valve block with its connecting portion cooperable with said throttle valve to operate the same upon swinging movement in one direction.

3. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed in one end and a hydraulic reservoir in the other end axially alined with said motor chamber, a motor piston reciprocable within said chamber, a motor valve block closing the end of said motor chamber remote from said reservoir, said motor Valve block including inlet and discharge passages and a throttle valve, a hydraulic valve block interposed between said motor chamber and said reservoir, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages and a release valve, a piston reciprocable in said pumping chamber and having a portion extending into said motor chamber for coaction with said motor piston, and an actuating lever having a pair of legs swingably mounted on opposite sides of said hydraulic valve block and a connecting portion cooperable with said throttle valve to operate the same upon swinging movement of said lever in one direction, said lever also being cooperable with said release valve to control the same.

4. A fluid actuated pump according to claim 3, wherein the throttle actuating portion of the lever lies in one plane and the release valve controlling portion of the lever lies in another plane located outwardly of the plane of said throttle actuating lever.

5. A fluid actuated hydraulic pump comprising, a body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor valve block including fluid inlet and exhaust passages and a throttle valve, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber and hydraulic inlet and exhaust passages and a pressure release passage, a valve in said hydraulic valve block controlling said release passage, a piston reciprocable in said pumping chamber and operable by said motor piston, a lever swingably mounted on said hydraulic valve block, said lever having a portion cooperable with said throttle valve to operate the same upon swinging movement in one direction, and valve actuating means carried by another portion of said lever and cooperable with said release valve to open said release passage upon swinging movement of said lever in the opposite direction.

6. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor valve block including fluid inlet and exhaust passages and a throttle valve, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages and a pressure release passage, a release valve in said hydraulic valve block normally seated in said release passage to close the same, a piston reciprocable in said pumping chamber operable by said motor piston, and an actuating lever pivotally mounted on said hydraulic valve block, said lever having a portion cooperable with said trottle valve to operate the same upon swinging movement in one direction, and means formed on the lever pivot for cooperation with said release valve to unseat the same and open said release passage upon swinging movement in the opposite direction.

7. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor valve block including inlet and exhaust passages and a throttle valve, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and bydraulic inlet and exhaust passages and a pressure release passage, check valves in said hydraulic valve block controlling flow through said hydraulic inlet and exhaust passages, a release valve in said hydraulic valve block normally seated in said release passage to close the same, a piston reciprocable in said pumping chamber operable by said motor piston, an actuating lever pivotally mounted on opposite sides of said hydraulic valve block, said lever having a portion cooperable with said throttle valve to operate the same upon swinging movement in one direction, means formed on one of the pivots of said lever for cooperation with said release valve to unseat the same and open said release passage upon swinging movement of said lever in the opposite direction, and means accessible through the other of said lever pivots and coacting with the valve controlling the hydraulic exhaust passage for resiliently urging the same to seated position.

8. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor valve block including inlet and exhaust passages and a throttle valve radiating therefrom, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages and a pressure release passage, said motor chamber and pumping chamber being coaxially alined, check valves in said hydraulic valve block, controlling flow through said hydraulic inlet and exhaust passages, a release valve in said hydraulic valve block normally seated in said release passage to close the same and having an actuating portion radiating from said hydraulic valve block in a different radial plane than that of said throttle valve, a piston reciprocable in said pumping chamber, an actuating lever pivotally mounted on opposite sides of said hydraulic valve block, said lever having a portion cooperable with said throttle valve to operate the same upon swinging movement in one direction and having one of its pivots coupled to the actuating portion of said release valve whereby said release valve is unseated to open said release passage upon swinging movement of said lever in the opposite direction, and means accessible through the other of said lever pivots and coacting with the check valve controlling the hydraulic exhaust passage for resiliently urging the same to seated position.

9. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor valve bloc-k including air inlet and exhaust passages, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages, a piston reciprocable in said pumping chamber and having a portion coacting with said motor piston, a tubular member forming a high pressure hydraulic discharge passageway extending from the exhaust passage formed in said hydraulic valve block axially away from the adjacent end of said body, and a flexible membrane having one end secured to the periphery of said hydraulic valve block and the other end secured about said tubular member remote from said hydraulic valve block for confining reserve fiuid therein.

10. A fluid actuated hydraulic pump comprising, a unitary body provided with a removable portion forming a motor chamber, a motor piston reciprocable within said chamber, a motor valve block removably secured to and closing one end of said motor chamber, said motor valve block including air inlet and exhaust passages, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve bloc-k including hydraulic inlet and exhaust passages and a threaded bore opening at one end into said motor chamber, a threaded cartridge removably confined within said bore and having a pumping chamber extending therethrough, and a piston reciprocable in said pumping chamber and having a portion extending outwardly from said cartridge into said motor chamber said motor piston being accessible upon removal of said motor valve block and said cartridge and its piston being accessible upon removal of said motor chamber forming portion.

11. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, means forming a passageway in said motor valve block for supplying pressurized fluid to the adjacent end of said motor chamber, a throttle valve for controlling the flow of pres surized fluid through said supply passageway, means forming an exhaust passageway in said motor valve block communicating with opposite ends of said motor chamber, a one way check valve for said exhaust passage normally sealing the same from ingress of exterior air and foreign matter while permitting escape of exhaust air therefrom, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages, and a piston reciprocable in said pumping chamber and having a portion coacting with said motor piston.

'12. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, said motor chamber having a vent communicating therewith remote from said motor valve block, means forming a passageway in said motor valve block for supplying pressurized fluid to the adjacent end of said motor chamber, a throttle valve for controlling the flow of pressurized fluid through said supply passageway, means forming an exhaust passageway in said motor valve block communicating intermittently with the adjacent end of said motor chamber and constantly with the remote end of said motor chamber, resilient cup-shaped member covering said exhaust passage to provide a one way check valve normally sealing said passage from ingress of exterior air and foreign matter while permitting escape of exhaust air therefrom, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages, and a piston reciprocable in said pumping chamber and having a portion coacting with said motor piston. I

13. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, ieans forming a passageway in said motor valve block for supplying pressurized fluid to the adjacent end of said motor chamber, a throttle valve for controlling the flow of pressurized fluid through said supply passageway, means forming an exhaust passageway in said motor valve block communicable with the adjacent end of said motor chamher, a reciprocable spool valve freely slidable in said motor valve block and operable to establish communication alternately between said supply passageway and said motor chamber and between said exhaust passageway and said motor chamber, said valve having diflerential areas at the opposite ends thereof and being reciprocated in one direction by pressurized fluid supplied from said motor chamber and in the opposite direction by direct action of said motor piston, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages, and a piston reciprocable in said pumping chamber and coacting with said motor piston.

14. A fluid actuated hydraulic pump comprising, a unitary body having a motor chamber formed therein, a motor piston reciprocable within said chamber, a motor valve block closing one end of said motor chamber, means forming a passageway in said motor valve block for supplying pressurized fluid to the adjacent end of said motor chamber, a throttle valve for controlling the flow of pressurized fluid through said supply passageway, means forming an exhaust passageway in said motor valve block communicable with the adjacent end of said motor chamber, a reciprocable spool valve loosely slidably confined in said motor valve block and operable to establish communication alternately between said supply passagea,oa1,975

way and the adjacent end of said motor chamber and between said exhaust passageway and the adjacent end of said motor chamber, passage means extending between said motor chamber and one end of said spool valve and controlled by said motor piston for intermittently admitting pressurized fluid from said motor chamber to said valve end to reciprocate said valve in one direction, said valve having a portion extensible into said motor chamber for direct operating contact with said motor piston for reciprocation thereby in the opposite direction by direct action of said motor piston, a hydraulic valve block closing the other end of said motor chamber, said hydraulic valve block including a pumping chamber of reduced size and hydraulic inlet and exhaust passages, and a piston reciprocable in said pumping chamber and coacting with said motor piston.

15. A fluid motor comprising a body having a motor chamber formed therein, a piston reciprocable within said chamber, a valve block closing an end of said motor chamber, means forming a passageway in said valve block for supplying pressurized fluid to the adjacent end of said motor chamber, a throttle valve for controlling the flow of pressurized fluid through said supply passageway, means forming an exhaust passageway in said valve block communicable with said motor chamber, a reciprocable spool valve freely slidable in said valve block and operable to establish communication alternately between said supply passageway and said motor chamber and between said exhaust passage and said motor chamber, and passage means extending between said motor chamber and one end of said spool valve and controlled by said piston for intermittenly admitting pressurized fluid from said motor chamber to said valve end to reciprocate said valve in one direction, said valve having a portion extending into said motor chamber for direct contact with said motor piston for reciprocation thereby in the opposite direction by direct action of said motor piston.

References Cited in the file of this patent UNITED STATES PATENTS