US2255984A - Hydraulic pump system - Google Patents

Description

Sept. 16, 1941. PFAUSER 2,255,984

HYDRAULIC PUMP SYSTEM Filed Oct. 21, 1959 2 Sheets-Sheet l INVENTOR ATTORN EY,

Sept. 16, 1941. M PFAUSER 2,255,984

HYDRAULIC PUMP SYSTEM Filed Oct. 21, 1939 2 Sheets-Sheet 2 Patented Sept. 16, 1941 HYDRAULIC PUMP SYSTEM Edward M. Pfauser, Elm Grove, Wis, assignor to Blackhawk Mfg. 00., Milwaukee, Wis., a corporation of Wisconsin Application October 21, 1939, Serial No. 300,501

2 Claims.

My present invention relates in general to improvements in hydraulic pump systems for transferring power hydraulically from one place to another, and relates more specifically to improvements in the construction and operation of hydraulic systems embodying a jack operable at various selected speeds by means of a unique pump and supply reservoir assemblage.

Generally defined, an object of my present invention is to provide an improved hydraulic pump system which is flexible and highly efiiclent in use, and the various elements of which are effectively operable when disposed in various positions.

It has long been common practice in garages and other establishments, to utilize hydraulic systems comprising a portable pump and supply reservoir connected by flexible tubing to an independently portable jack assemblage, for the purpose of performing various operations with the jack. In this type of equipment, the liquid supply reservoir is ordinarily associated directly with the pump which is frequently operable by hand and has a piston for withdrawing liquid from the reservoir and for delivering the same under pressure through the flexible tubing to the remotely disposed jack; and the pump usually has a by-pass valve for permitting return of the liquid from the jack to the reservoir past or around the pump piston. The jack is normally disposable in any desired position independently of the pump by virtue of the flexibility of the connecting tubing, and in order to insure positive return of the liquid from the jack to the reservoir when the by-pass valve is opened, the jack plunger should be positively urged toward collapsed or inactive position by means' of a spring or the like. While the jacks of these prior systems may be disposed in any desired position, the pumps which depend upon gravity feed of liquid from the supply sources, must be located with the inlet ports thereof constantly disposed below the liquid level in the reservoir in order to prevent introduction of air into the hydraulic pressure system. This prior gravity type of assemblage therefore requires careful positioning of the pump with respect to its supply reservoir, which the available space and location of the apparatus willnot always permit, and the utility of these prior systems is therefore limited by virtue of this gravity feed. The prior systems of this general type ordinarily make provision for only one speed of operation of the pump by virtue of uniform stroke of the operating handle, and this feature is also objectionable when operating under cramped conditions as it does not permit most effective delivery of liquid at desired pressures to the ram or jack. It is therefore a more specific object of the present invention to provide various improvements in hydraulic jack or ram systems, whereby both the pump and the jack may be disposed in any desired position and most efiectlvely operated to insure the best results under varying conditions of operation.

Another specific object of my invention is to provide an improved pump-jack assemblage of the type wherein the jack plunger positively is returned to inactive position by a spring or other quick acting mechanical means whereby the excess liquid in the hydraulic system is returned directly to the supply reservoir, and in which atmospheric pressure augmentedv by the pump suction insures a proper supply of liquid to the pump regardless of the disposition of the latter.

An additional specific object of this invention is to provide a pump actuated hydraulic jack system in which atmospheric pressure alone acting upon the liquid in a supply reservoir, will insure an abundant supply of air-free liquid to the pump and jack irrespective of the disposition of either of these elements.

A further specific object of my invention is to provide an improved combined pump and jack assemblage wherein the operation of the pump may be quickly and effectively varied to actuate the jack plunger or ram at different selected speeds, and with different predetermined pressures acting thereon.

Still another specific object of my invention is to provide various improvements in independently portable pump and jack hydraulic systems, whereby the construction thereof is simplified, the operation is facilitated, and the usefulness is enhanced to a maximum.

These and other specific objects and advantages of the invention will appear in the,

course of the following description.

A clear conception of the several features constituting the present improvements, and of the mode of constructing and of utilizing pump-jack systems built in accordance with the invention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. l is a part sectional view of a complete hydraulic pump actuated jack system, longitudinal central sections having been taken through the pump, supply reservoir, and jack.

Fig. 2 is a top view of the pump and liquid supply reservoir of the system of Fig. 1;

Fig. 3 is a rear end view of the pumpand liquid supply reservoir, looking toward the reservoir;

Fig. 4 is a front end view of the pump and liquid supply reservoir, looking toward the pump;

, Fig. 5 is a transverse vertical section through filling valves; I

Fig. 6 is another transverse vertical section through the pump, taken centrally through the pump piston chamber; I

Fig. 7 is an enlarged transverse central section through'the rotary by-pass control cam;

Fig. 8 is a plan view of the rotary by-pass control valve cam; and

Fig. 9 is a diagram showing the various elements of the system disposed in a common plane.

While the various features of the improvement have been shown and described herein as being specifically embodied in a three-speed hydraulic pump and jack system wherein the liquid supply reservoir is directly connected tothe pump, and in which the pump and jack are independently positionable, it is not my desire or intent to thereby unnecessarily restrict the scope or utility of the invention.

Referring to the drawings, the improved portable hydraulic power unit or system illustrated therein, comprises in general a manually operable three-speed pump having a casing l provided with large and small bores ll, I2 respectively within which alined large and small integrally united pistons l3, I4 are simultaneously,

reciprocable by means of a common actuating handle or lever IS; a liquid storage and supply reservoir consisting of a tubular casing I6 rigidly secured to one side of the pump casing Ill and having therein a movable or floating wall H, the reservoir also being provided with a closure cap l8 a hydraulic ram or jack having a cylinder l9 provided with a bore 20, and a plunger 2| movable along the bore and positively returnable to retracted or inactive position by means of a helical tension spring 22; a flexible conduit 23 connecting the ram cylinder [9 with the opposite side of the pump casing l0 so as to permit independent positioning of the pump and jack} and valves for controlling the flow of liquid from the reservoir to the pump, from the pump to the jack, and from the pump and jack back to the reservoir.

The improved pump is of the three speed type, adapted to either actuate the jack. at high speed with minimum power, or at moderate speed with greater than minimum but less than maximum power, or at low speed with maximum power. This pump assemblage is shown diagrammatically in Fig. 9, and it is to be noted that the large diameter piston I3 has a displacement chamber 24 which is communicable past a suction valve 25 and through a conduit or suction port 25' with the liquid chamber 26 of the supply reservoir casing l6, and which is also communicable past a discharge valve 21 and through a port 28 with the flexible conduit 23 leading to the plunger displacement chamber 29 of the jack..

The small diameter pump piston l4 has a displacement chamber 30 which is communicable past a suction valve 3| and through another conduit or suction port 32 with the liquid supply chamber 26, and which is also communicable past a discharge valve 33 and through a port 34 with the flexible conduit 23 and chamber 29. The jack displacement chamber 29 and flexible conduit 23 are communicable through the port 34 and a passage 35 and past a manually operable relief valve 31, through another passage 38 directly with the supply chamber 26, and the passage 38 connects with the passage 35 in advance of the relief valve 31, and has an automatlc safety release valve 39 located therein. Above the safety valve 39 is located a removable filler plug 40 upon removal of which fresh liquid such as oil may be introduced into the system through a conduit 4|.

The piston displacement chamber 24 and the space between the suction and discharge valves 25, 21 of the larger pump section, is communicable through a passage 42 and past a check valve 43, with a conduit 44 which is in open communication with the supply chamber 26. The piston displacement chamber 30 and the space between the suction and discharge valves 3|, 33 of the smaller pump section, is likewise communicable through a passage 45 and past a check valve 46 with the supply chamber 26 through the conduit 44. The by-pass or check valves 43, 46 are pressed toward their seats by springs 41 but may be positively lifted against the spring and fluid pressure acting thereon by means of a manually adjustable rotary cam block 46 coacting with lifting pins 49, 50 which are engageable with the by- pass valves 43, 46 respectively.- The bypass assemblage is obviously such that either of the valves 43, 46 may be open, or both valves may be closed. When both valves 43, 46 are closed as in the diagram of Fig. 9, and with the relief valve 31 also closed, operation of the pump pistons I 3, l4 will cause liquid to be delivered from the supply chamber 26 to the jack by both pistons thus producing maximum speed; whereas if the valve 43 alone is open, the large piston l3 will be inactive thus producing minimum speed; while. opening of the valve 46 alone will make the small piston l4 inactive thus producing intermediate speed.

Referring again to the commercial structures shown in Figs. 1 to 8 inclusive, the pump casing in may be formed as a single casting provided with supporting feet 5|, and has the reservoir tube l6 attached by screw threads to a socket 52 formed in one side of the casing. The opposite side of the casing ill, to which the flexible conduit 23 is attached by means of a connector plug 53, is provided with laterally spaced integral ears 54 to which the lever ,or handle I5 is swingably attached by a pivot pin 55. The portion of the hand lever l5 which is swingable in alinement with the bores H, l2 and pistons l3, I4, is provided with a transverse pin 56 which coacts'with a cross-head 51 secured to the large piston I3; and the portion of the handle l5 which swings over the plug 40 may be provided with a through opening 58 for permitting convenient access to the plug 40 in order to facilitate filling and drainage of the hydraulic system. The swinging end portion of the handle l5 may be caused to coact with a releasable hook 59 carried by the outer section 60 of the closure cap l8, and this cap section 60 may also be provided with supporting feet 6|. The inner section 62 of the cap l8 has a threaded socket secured to the end of the reservoir tube l6 remote from the pump casing I0, and the section 62 has a threaded central projection 63 provided with an atmospheric vent opening 64 and is rigidly attached to the outer section 60 by means of a nut 65. The floating piston or wall I! which is freely movable within the cylindrical tube l6 of the liquid supply reservoir, is preferably provided with oppositely directed cup-leather packing rings 66 held in place by retainer rings 61, and has a central passage 68 which is normally sealed by a plug valve 69, but which may be opened to atmosphere during filling of the hydraulic system so as to permit escape of air from the chamber 26. It is noteworthy, that whenever the pump. pistons I3, M are moved so as to open either or both of the suction valves 25, 3|, the pressure within the chamber 26' will be slightly reduced, and atmospheric pressure acting upon the face of the wall remote from the chamber 26 will then act to automatically advance the piston or wall toward the pump regardless of the position of the pump; and when the relief valve 31 is open so as to connect the conduit 23 with the chamber 26 the spring 22 acting upon the plunger 2| will cause this plunger to force the liquid from the chamber 29 into the chamber 26 thereby causing the wall to move away from the pump, regardless of the position of the jack or of the pump.

.The large piston |3 may be packed by means of sealing rings as shown in Figs. 1 and 6, and the small piston |4 may be sealed against leakage by a packing ring so that no liquid can ordinarily escape from the chamber 24 to atmosphere, or from the chamber 38 to the chamber 24. The valves 25, 21, 3|, 33, 43, 46 are all of the ball type, but need not necessarily be of this specific type, and the pump valves 25, 21 are confined within their zone of action and are accessible by means of a removable spacer 12, while the pump valves 3|, 33 are similarly confined by a removable spacer 13, see Figs. 2, 6 and 9. The valves 43, 46 and springs 41 are normally confined by removable plugs I4 shown in Figs. 5 and 9; and the safety relief valve 39 is normally held to its seat by a spring the tension of which is adjustable by means of a screw plug 16, see Figs. 5 and 9. The by-pass or pressure release valve 31 has a spindle provided with a threaded portion coacting with threads on the casing l8, and is operable from the exterior of the pump casing by a handle or lever 18, see Fig. 2. The by-pass valve actuating cam 48 is located directly within the liquid supply chamber 26 as indicated in Fig. 5; and has a series of detents 19 on one face thereof, which are adapted to coact with the valve lifting pins 49, 58 when the cam 48 is rotated, so as to either open one valve 43, 46 only, or to open both of these valves, or to permit the springs 41 to close both valves. The cam 48 is secured to an actuating stem 86 which extends outwardly of the casing I9 and is provided with a handle or lever 8| having a pointer 82 adapted to cooperate with indications 33 as shown in Fig. 2.

The ram or jack which is positionable independently of the pump and supply reservoir by virtue of the flexible tube or conduit 23, may also be attached to this conduit by means of a fitting 53, and the plunger 2| is hollow and has the returning spring 22 confined therein. The tension of the spring 22 may be adjusted by means of a screw 84, and the plunger 2| has packing rings 85 coacting with the cylinder bore 26 and is guided by a ring nut 86 secured to the cylinder l9, see Fig. l. The outer end of the plunger 2| may be provided with a head 81 which is threaded for attachment to a variety of implements, and the cylinder I9 may also be provided with a threaded socket 88 to which jack extensions such as rods or pipes may be attached. The important feature of this ram or jack, is that it is positionable independently of the pump, and the plunger 2| is always positively returnable to retracted or inactive position by the spring 22 whenever the liquid return valve 31 is opened, and regardless of the position of the jack.

During normal use of the improved hydraulic apparatus, the reservoir chamber 26, pump displacement chambers and ports, conduit 23, and jack displacement chamber 29 should first be completely filled with suitable liquid such. as oil, which may be admitted to the system upon removal of the plug 48 and through the port 4|. When the system is being thus filled with oil, the reservoir tube |6 should be so positioned that the central passage 68 in the floating piston or wall I! is at the highest point, and the vent plug 69 should be opened so as to permit free escape of all air from the hydraulic chambers, passages and conduits. If the plug 40 has been restored and the vent plug 69 has been closed, and with the jack plunger 2| in retracted position as shown in Fig. 1, the floating wall II should assume a position substantially as shown in Fig. 1 and the chamber 26 should contain an abundance of liquid suflicient to fully expand the jack. The jack plunger 2| may then be moved outwardly within the cylinder l9 at three different speeds and with correspondingly different powers. Assuming the rotary cam 48 to be set as shown in Fig. 9 wherein both relief valves 43, 46 are in closed position, oscillation of the handle I5 to reciprocate both pump pistons |3, |4, will cause both of these pistons to be effective to withdraw liquid from the cham ber 26 and to discharge the same through the conduit 23 to the jack displacement chamber 29, thereby causing the plunger 2| to move outwardly at maximum speed. The reciprocating large piston l3 will during it outward stroke, draw liquid through the passage 25 past the suction valve 25, and during the return stroke of the piston the liquid previously introduced into the displacement chamber 24 will be discharged past the valve 2! and through the passage 28 and conduit 23 to the jack chamber 29.

During the outward stroke of the piston l4, liquid Will be withdrawn from the chamber 26 through the passage 32 and past the suction valve 3|, and upon the return stroke the liquid thus admitted to the chamber 30 Will be discharged past the valve 33 through the passage 34 and conduit 23 to the chamber 29. During such reciprocation of the pump pistons, the return valve 31 will, of course, be closed, and the safety valve 39 will also remain closed unless the pressure in the chamber 29 becomes excessive, whereupon the valve 39 will automatically open and will permit liquid to escape through the passage 38 to the chamber 26. With both pistons l3, I4

thus reciprocating, the jack plunger 2| will be moved outwardly at the maximum speed due to the combined action of both the large and small pump.

If the cam 48 is rotated so as to remove the valve 46 from its seat, reciprocation of the two pistons |3, M will cause the large piston |3 alone to become active in delivering liquid under pressure to the chamber 29. The small piston M will not under such conditions of operation withdraw liquid irom the chamber 26, and if liquid should enter the displacement chamber 39, this liquid will merely be returned to the chamber 26 past the open valve 46 and through the passages 45, 44. If the other relief valve 43 is opened by manipulation of the cam 48, and. the valve 46 remains closed, then the piston |4 alone will be efiective in delivering liquid to the jack displacement chamber 29. The large piston |3 will not under such conditions withdraw liquid from the chamber 26, and any liquid which may be confined in the displacement chamber 24 will be returned to the chamber 26 through the passages 42, 44. When the large piston I3 is active alone, then the jack plunger 2| is being moved outwardly at an intermediate speed and with somewhat reduced power; but when the small piston l4 alone is active, then the jack plunger 2| is being moved outwardly at minimum speed but with maximum power. If the rotary cam 48 is adjusted so as to open both valves 43, 46, operation of the pump will produce no movement of the jack plunger 2|. If the return valve 31 is opened, the spring 22 of the jack will immediately become effective to return the plunger 2| to retracted or inactive position, and the plunger 2| will then force liquid from the chamber 29 through the conduit 23 and passages 34, 35 into the chamber 26.

From the foregoing detailed description it will be apparent that the improved pump is con-veniently manipulable and operable to cause the jack plunger 2| to move outwardly at three. difierent speeds. During the suction stroke of each pump piston l3, l4 liquid is, of course, withdrawn from the chamber 26, and the reduced pressure'caused by these suction strokes, combined with the atmospheric pressure acting upon the side of the wall l! remote from the chamber 26, will cause the movable wall I! to constantly advance toward the pump and to maintain anab-undant supply of liquid for the pump regardless of the disposition thereof. However, when the return valve 31 is opened the spring 22 which positively returns the jack plunger 2| to retracted position, immediately becomes effective to force the excess liquid back into the chamber 26, thereby forcing the wall I! away from the pump in opposition to the atmospheric pressure acting thereon. This action of the jack plunger 2| is positive and takes place regardless of the disposition of the jack, thereby insuring return of the liquid to the chamber 26 irrespective of the position of any of the elements. Both the cam 48 and the return valve 31 are conveniently manipulable from the exterior of the pump casing l0, and all parts of the assemblage while being well protected during normal use, are readily accessible for inspection. The movable wall H which floats within the tube I6, also serves as means for venting the hydraulic system, and while this wall is confined within and protected by the tube I6, it is at all times open to atmospheric pressure through the passage 64 in the closure cap. The provision of feet 6| on the pump casing and closure cap, provides a means for supporting the pump and supply reservoir in horizontal position and the hook 59 permits the handle l5 to be retained closely adjacent to the supply reservoir when the pump is not in use and thus provides a handle for the purpose of conveniently carrying the pump assemblage. The relief valve 39' prevents damage to delicate parts in case the jack isoverloaded, and the entire unit is obviously simple and compact in construction and can be readily manipulated by a novice. The combined pump and jack system has proven highly successful in actual commercial use, and the floating wall I! cooperating with the positively returned plunger 2| of the jack have proven especially valuable in maintaining an abundant supply of liquid for the pump while preventing entry of air to the hydraulic system.

. voir remote from said pump frame, said cap com- I a It should be understood thatit is not desired.

to limit this invention to the exact details of construction or to the precise mode of use, herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

I claim:

1. In combination, a relatively light portable ram unit adapted to be readily positioned by an operator in practically any working position relative to the work, said ram unit including 2. cyllnder and a plunger provided with a spring constantly and positively urging the plunger into the cylinder, a hydraulic pump unit having a frame forming a displacement chamber and a piston cooperable with said chamber, a flexible hose connecting said ram cylinder with said pump frame and chamber, an elongated tubular liquid supply reservoir secured to said pump frame and being communicable with said pump chamber, non-return valves controlling flow from said reservoir through said chamber to said hose, a by-pass valve adapted to connect said cylinder and hose directly with said reservoir around said pump chamber, a floating partition within said reservoir movable therealong in one direction by liquid compressed by said spring and in the opposite direction by atmospheric pressure opposed to pump suction, and a closure cap for the end of said reservoir remote from said pump frame, said cap comprising an inner section having one end detachably secured directly to the reservoir to form a stop for said partition and its opposite end provided with a hollow vent projection, and an outer section embracing said inner section and secured to said projection, said outer section cooperating with said frame to provide a base for normally supporting said reservoir in approximately horizontal position.

2. In combination, a relatively light portable ram unit adapted to be readily positioned by an operator in practically any working position relative to the work, said ram unit including a cyllnder and a plunger provided with a spring constantly and positively urging the plunger into the cylinder to expel liquid from the latter, a hydraulic pump unit having a frame forming a displacement chamber and a piston cooperable with said chamber, a flexible hose connecting said ram cylinder with said pump frame and chamber, an elongated tubular liquid supply reservoir secured to said pump frame and being communicable with said pump chamber, non-return valves controlling flow from said reservoir through said chamber to said hose, a by-pass valve adapted to connect said cylinder and hose directly with said reservoir around said pump chamber, a floating partition within said reservoir movable therealong in one direction by liquid compressed by said spring and plunger and in the opposite direction by atmospheric pressure opposed to pump suction, a closure cap for the end of said reserprising a section detachably secured directly to the reservoir to form a stop for said partition and having a central projection, and a supporting section adjustable about the axis of said projection and cooperating with said frame to provide a base for normally supporting said reservoir in approximately horizontal position.

EDWARD M. PFAUSER.

Images