US2156543A - Hydraulic jack - Google Patents

Description

Patented ueisers l -aanmo .mok Edward M. Hauser, Elm Grove, Wis., assigner to Blackhawk Mfg. o., 1' ukgea; a oorporation o! Wisconsin s Application January is, issneriai No. 59,651

, 21 The present invention relates generally to lift` ing jacks and similar devices and is partimilarly concerned with garage jacks for automobiles and according to the principles of the present invenof the load carrying means;

FigureZ is a top plan view of the jack shown the pivot pin 36 serves the'dual purpose of mov- .thelike `in Figure l At the present time, automobiles are' designed Figure 3 is a vertical section taken substantially 5 with an' extremely long overhang, and with tires longitudinally through the central portion of the deated the clearance between the bumper. actuating mechanism and corresponding ap' fenders, skirts and other overhanging parts and proximately toa section taken along the line 8-8 the groundis comparatively small, which makes oi v1iig11re'5;

l0 it `dimcult to place a jack of conventional con- Figure 4 is a section taken substantially along 10 struction far enoughunder the car to engage the the line of Figure 2 looking forwardly; axle while, at the same time, affording an oppor- Figure 4A is a section taken substantially along tunity to actuat'e the lifting handle through a the line dfi- 5A of Figure 2 1ooking rearwardly; sufficiently wide angle to rapidly raise the load. Figure 5 is a sectiontaken substantially along This is especially true of mechanical jacks, in the line 5 5 of Figure 3; and 15 which the lifting handle must be swung throimh Figure- 6 is an enlarged section taken through a predetermined angle in order to secure eiec-4 the outer end of the jack operating handle. tivel operation of the ratchet mechanism there- Referring now to the drawings, particularly of.- The principal object of the present invention Fig-ure 1, it will be observed that the `jack oonis the provisionof a jack that is very low at its structed according to the principles of the pres- 2o front end and iS prvded with actuating mehent invention embodies a jack frame indicated nism spaced far enough toward the rear 0f the in its entirety by the reference numeral l and jack S0 aS t0 Clear OVerh/Ilging Skirts, fenders, including apair of channelled side plates or frame bumpers and other parts of the automobile. By bars 2 and 3 (Figure 2) load supporting and lift- 25 virtue of this construction, the operating handle ing mechanism 5 and a power unit 6. The frame 25 lian be manipulated i'fhl'Ollgh a'A relatively wide l is supported upon a pair of wheels 8 at its front angie, thereby facilitating the raising 0f the Y'end and a second pair of wheels 9 at its rear 1091i- Y end. The front wheels 8 are mounted for rota- Another object of the present' invention is the tion on an axle Il supported in apertured bosses provision of a jack which is not only very low l2 formed at the front ends of the frame bars 30 at the lifting end thereof but, moreover, is' par- 2` and 3, the latter being rigidly secured to the tcularly arranged to provide a relatively lhigh axle by means of axle lock pins it. The wheels lift and which, in addition, is so constructed that o are held for rotation on the axle by any suitable the actuating mechanism is disposed out of the means such as cotter pins l5. The Wheels 9 at way of overhanging parts. A further object oi the rear end of the frame are mounted on stud the present invention in this connection is the bolts 20 and 2l which pass through apertured provision of a jack having a hydraulic power bosses 22 and 23 at the rear ends of the frame unit having an operating ram or plunger in direct bars 2 and 3 and are threaded into the power contact with a lifting lever, thereby eliminating unit housing, as best shown in Figure 4. The stud 40 links and the like and, at the saine time, prob'iilS W and 2i Carry bushings 26 1110.011 Which 40 viding a more direct application of the power to the Wheels 9 are Journaled and each-of-which is the lifting arm and aordlng an ppm-unity to provided with a reduced section 2l having a employ 9, lifting arm capable of raising-@glow shoulder 28 bearing against the outer face of to a considerable height and yet capable f en the associated frame bar. The inner end of each gaging a load at a relatively low pgoint. of the bushmgs 2s is disposed m an' opening 3' i5 A further object of the invention to proyde 'with sumcient clearance 3l therein so that the a hydraulic jack of simple and rugged construcitud 00H5 may be tightened to cause the bush' tion, employing a relatively small number of parts mg to rmly clamp the associated side bar against and securing maximum efficiency. the power unit housing. At the same time, the

' rii'hese and other objects and advantages -of- '-shomdered portion 28 is so imposed that' the 50 th Y rear wheel mounted thereon has sucient cleare present invention will be apparent to, those skilled in the art after a consideration of the folance for free rotation' i lo d t il d d ti f th -f d t s The lifting mechanism 5 includes-alifting arm Wlfllg e a i escnp ono emi@ erre s 3 or lever 35 which is pivotally mounted upon a 5r, tum' embodlmnt take? in omunction Wlih fulcrum pin 36. 'Ihe pin 36 has both ends thread'- 55 the a-comp-a'nymg drawings mustrating Such ed to receive hexagonal nuts 3l, and the central "embodiment portion of the bolt or; pin $3 is enlarged so as Iii the drawings: n to provide shoulders 39 adapted to engage the Figure l is a side View of a jack constructed inner surfaces of the frame bars 2 and 3. Thus, B0 60 ably supporting the'lifting lever 35 and, at the same time, holding the side frame bars 2 land 3 l rigidly in proper spaced relation.

' ing load supporting section 4| and a power receivingann section 42, the former extending from` the pivot 35, which is disposed on the frame adjacent the power unit 5, to the opposite end of the frame. The power receiving arm 42 extends generally downwardly and rearwardly from the pivot 35 to a point where it is in contact with the hydraulic actuating mechanism, as will be described later. 'I'he outer or front end of the lifting arm 35 carries a pivot pin 45, having a reduced apertured end 45 for this purpose, and a load supporting saddle 41, provided with a pair of laterally spaced apertured lugs 48 and 48 receiving the pin 45, is mounted on the latter for pivotal motion with respect thereto. The saddle lugs 48 and 48 are extended, as at 55 (Figure 1), and

, these portions of thesaddle are apertured to receive a pivot pin 5| to which the forward or outer ends of a pair o f links 53 and 54 are connected.

These links extend alongside the load supporting lifting arm section 4| and between the'latter and the frame bars 2 and 3, as best shown in Figure 2. The inner or rear ends of thelinks 53 and 54 are mounted upon an anchoring pivot pin 55` which is disposed in a pair of .apertured bosses 51 and 58 carried on the inner sides of the frame bars 2 and 3, and a pair of cotter pins 50 are utilized to hold the pivot pin 55 in position. 'I'he relation between the pivots 35, 45, 5| and 55 is such that la parallelogram is formed, and the forwardly extending section 4I of the lifting lever and the links 53 and 54 thus serve to maintain the load supporting saddle .41 in a horizontal position at all times, regardless of the elevation of the 'lifting mechanism 5. l.

A pair of springs 52 and 53 are disposedon-opposite sides of the vcentral web 4|a of the lifting and 55 disposed around and 'connected to the pivot 55. The forward ends of the springs 52- and 53 are hooked into openings' 58 formed in the outer end of the lifting lever'35. The function o f` the springs 52 and 53 is to bias the lifting'mechf Y lever 35, as indicated at 58.

vention, and in` order to provide a jack in which the lifting mechanism can be disposed in a very low position and which can also be raisedv to a -relatively high pomtion, the rear or power receiving end 42 of the lifting lever 35 and the pivotal supportof the latter are disposed closely ad 1 jacent to the power unit 5 which is carried at the rearmost endof the frame I,l and the operating mechanism of theA power unit 5 is particularly arranged to operate efficientlyv against theclosely adJacent end of the lifting arm 35. Referring now more particularly to Figures 3,- 4 and 5, the housing or casing of theI power unit is indicated at 18 andis preferably in the form of an integral castinghavinga forwardly disposed reduced boss section 1| which is apertiired, as at 12,*to receive bolt means 14. The bolt 14 has its opposite ends threaded and disposed in apertured bosses 15 and 15 carried or formed 'on the frame members. Nuts 'I1 are disposed on, the threaded ends of the According to the principles of the present inv or` the like, and formed in the central longitudinal portio'n thereof with a ram plunger receiving cylinder 84 which extends rearwardly, as at 85, and is provided with an open forward end threaded a's at 85 and 81. 'Suitable thickened portions 88 are provided and are threaded, as at 88a, to receive the inner ends of the stud bolts and 2| by which the rear wheels 8V are mounted as described above. Adjacent the side wall 8|, the housing'. y

18 is provided with an enlarged wall section 88 forming a pump cylinder 8|) disposed in a longitudinal position alongside thelongitudinally disposed ram cylinder 84. 'I'he pump cylinder 88 is open at its rear end and is threaded, as at 8| and 82, and the innermost end of the pump cyl-` inder 88 communicates through a horizontal bore 94 with a vertical bore 85, as best shown in Figure 3, and the lower portion of the latter is in communication with a transverse horizontal bore or duct 81 which extends underneath the ram cylinder 84, as best shown in Figure 5, and is in communicationthrough v,a screen 88 with the space at one side of and above the cylinder 84 which formsI a sump 88 for the hydraulic operating mechanism. The side wall 82 of the casing 18 carriesa threaded boss |88 which receives the outer end of the strainer or screen 88, and a plug .|8| is utilized for holding the screen 88 in place. A check valve in the form of a -ball |82 is disposed in the lower end of the vertical duct 85 and f serves to prevent a flow of liquid from the duct or conduit 85 through the bore 81 to the sump 88, but the movement of liquid from the sump to the lower portion of the bore 85 is not interfered with, this being the inlet to the pump mechanism. A filler plugA 88a in the wall 82 provides for charging the sump with liquid and checking the level of the latter. arm 35 and anchored at their rear ends to links 55 -1 A pressure'check ball |83 permits a ow of liquid from the pump mechanism to the upper portion of the bore 85. A horizontal bore |85 establishes communication between the upper portion ofthe bore 85 and the interior of the plunger cylinder 84. The uppermost end of the vertical bore 85 is threaded as at |81.(Figure 5) and receives a relief valve mechanism |88 which opens under excess pump pressure and permits .the discharge from the pump to ow directly into the sump 88.-

A ram or plunger ||2 is disposed for longitudinal movement in the plunger cylinder 84, and the outer. or operatingvend of the latter is providedwith a thrust plate I3 having a stem ||4 suitably disposed'and secured in an opening ||5 formed in the outer or forward end of the plunger I2. The member, ||3 is preferably of .hardened construction vand is arranged to Vbear against aroller ||1 (Figures l and 2) rotatably mounted on Aa p ivot pin ||8 carried in the arms ||8and |28 of the bifurcated rear or lower end of the power receiying arm 42 which forms a part of the lifting lever 35. 'I'he lifting lever 35 is provided with a s1ot..|2| (Figure 1) which is arcuate about the pivot 35 at its center and receives the link Ai'ulcrum pin 55 Awhichas described above, extends from one side frame mem ber to the other.

'Ihe threaded Asections 85 and 81 of the plunger cylinder 8 4' receive suitable packing means for rendering'the cylinder leak-tight. A packing spreader |22 is disposed in the bottom of the ther outward movement of the ram ||2 will take threaded sections 86 and 81, and V-packing'l28 isforced against .the spreader |22 by a packing spacer |24, the latter having a head in threaded.

engagement with the threaded section 81 of the plunger cylinder 84. outwardly of the packing spacerA |24 is disposed .additional packing |25 which is forced into leak-tight relation by a packing nut |26. 'I'he'rear end of the ram or plunger I2 is formed with a horizontal bore. |2'| which communicates with a vertically disposedbore |28. The packing spacer |26 carries an annular groove or recess in communication with a small bore |24a which leads to a bore |29 formed in the upper portion oi the cylinder 84 and communicating with thesump 99. When the ram I|2 is forced outwardly, by mechanism to be described later, far enough for'the bore |28 to register with the bore |24a, the pressure behind the ram ||2 will berelieved and no furplace.l

Suitable pump mechanis'm is provided for actuating the ram ||2. Such mechanism includes a pump plunger |30 which is reciprocally mounted in the .pump cylinder 90 and is maintained in leak-tight relation by packing means similar to that described above, which includes a packing spreader |3I, packing |32, and a packing spacer |33. Additional packing |36 is provided and is forced into placeby a packing nut |35. The

outer or rear end of the 'pump plunger |39 is provided with a slotted head |90, having a slot `as at NIS.

The pump is actuated by .a pump handle |65 which includes a tubular section-|||6 (Figure 1)' secured byilock screws Iil to the tubular poi-tion |48 of a handle yoke |89. The latter member is provided with wing sections |50 apertured to receive a pivot pin |5| and one of which extends downwardly to form a bifurcated pump actuating arm |52. The arm |52 carries a pin- |53 which is disposed for operation in the slot Mi formed in the head |88 ofthe pump plunger |88. The pivot pin |5| for the pump handle is carried in a pair of laterally spaced ears |56 and |57 which are formed on a rear end 85 of the ram cylinder 88.

serves as a packing nut for tighteningthe pack- 'ing |68, around the valve |86. AThe vvalve l|66 controls the communication between the interior of the plunger cylinderli and the sump 99, rotationof the valye |66 in one direction moving the conical end thereof awayfrom its seat |562 and permitting liquid to flow through the bore |60 and the bore Mid-into the sump, thereby releasing the plungerv ||2 and permitting Nit to moveback intothe position s own in Figure 3. The'needle valve |66 is gui ed by the section |63, and the handlepivot |5I. is provided with a transverse bore |13 in which the outermost end of the valve |66 is rotatably supported.

The valve |66 is controlled by a release valve control rod (Figures 1 Yandv 6) which extends from the outer end of the handle |65to the lower end of the control rod |80 is connected by outer or rear end of the valve |66. The control rod |80 at its outer end is provided with a transverse hole to receive a pin |8| by which a control knob |82 is non-rotatably fastened to the rod |80. The knob |82 includes a reduced section |83 which is rotatable within the outermost end ofthe tubular handle section |46. This portion of the knob |82 is also provided with .a circumferential groove |88, and. a lock screw |81 is threaded into the handle |45 and is provided with an extended end |88 disposed in the groove |88 for thepurpose of holding the knob |82 and the control rod |80 connected therewith in proper position relativel to the handle |05. The

means of a universal jointI |90 with the outer end of the valve |86, the universal joint |90 iny cluding a tubular section |9| which carries a pin |92 slidable in a slot |92a in' the lower end of the control rod |80. The section |9| has a pair of apertured ears receiving a universal joint pin |98 carried by av universal 'block |96, and a second universal joint pin |95 is carried by the block and is received between the ears |98 (Figure 3) formed on the outer end of the valve 66. If desired, a. member such as the part |9| may be disposed on the upper or outer end of the valve |66 in lieu of the integrally formed ears |98.

The operation of the jack described above is l substantially as follows. Due to the fact that the load supporting saddle 5 in its lower position is disposed in an extremely low position, the jack may be placed under the axle of practically any automobile, notwithstanding that the deflation oi one or more of the tires may dispose the axle very close to the ground or Boor. After the load supporting. saddle Mis brought to the proper position under the load to be raised, the pump handle |96 is rocked, and this causes reciprocation of the pump plunger |30. It is to be noted 40 that the power unit 6 is disposed at the rearmost end of the elongated frame i and that the latter/is relatively low at all points, the power unit 6 being disposed even below the level of the upper part of the side frames 2 and 8, as best shown 5 in Figure 1. By virtue of this construction, the vertical angular travel of the handle |65 is not likely to be limited by any overhanging parts of the car, such as the fenders or bumpers, and

since the pump handle may be given a full stroke 50 without interference of any adjacent parts of the car, the pump is easily and conveniently operated. Repeated reciprocationsof the handle |85 pumpsy liquid behind the plunger vcylinder 89,

moving the thrust member ||3 against the roller H1. The forward or outward movement of the plunger thus brings the latter into direct contact with/the lower or rear end of the lifting lever 36, and plunger swings the load supporting lever section 5| and the load supporting saddle 81 upwardly,

the latter being held in proper position by the links 53 and 66. -As the plunger H2 moves outwardly, the roller moves a short distance 65 vertically across the face of the thrust plate H3, but the angular relation of the lower or rear end of the lifting lever 35 with respect to the pivot v 36 is'such thatth vertical shift of the roller I l1 isA less thanthe vertical dimension of the thrust 70 plate IIS. Iii--thisway, the full force of the plungeris available atall times to raise the lifting lever 35. Also, by thisconstruction the pivot 36 can be brought closely `adiacent tothe power unit 8 providing a relatively long liftingor load 76 forcing the ram or plunger ||2 forwardly and 55 continued outward movement of the 60 on said frame adjacent saidpower unit and insupporting section 4|-. As the plunger ||2 moves outwardly, its movement in this direction is'limited by the duct |28 coming into registration with ther ducts |24a and |29, and as soon as this occurs the -pump pressure is diverted and -the outward movement of the plunger ||2' ceases.

The lowering of the load is effected by turning the knob |82f'this acting through the control rod |80 to open and close the needle valve |66. Opening the valve |66, as is apparent, permits the liquid in the plunger cylinder 84 to pass through the bores |60 and 64 into the sump, and this allows the weight on the lifting lever 35 to force the plunger I|2 backwardly into the cylinder 84 to the position shown in Figure 3. The rapidity of descent is, of course, controlled by the degree of opening of the valve |66.

While I have shown and described above the preferred form; of my invention, it will be apparent to those skilled in the art/that thepres-v ent invention is not to be limited to the particular details shown and described above, but that,

in fact, widely different means may be employed in the practiceof thebroader aspects of my invention.- l

What I claim, therefore,and desire to secure by Letters Patent is:

1. A jack comprising a frame, a power unit mounted at one end on said frame and including a longitudinally movable plunger in the lower portion thereof, a'lifting lever pivotally mounted cluding a generally downwardly disposed power receiving portion and generally longitudinally disposed load supporting section extending to the,

other end ofthe frame, said power-receiving section of the lifting lever being incontact with said plunger so as to receive power therefrom, a load supporting saddle pivotally mounted at the outer.

end of said lifting leven/link means extending alongside said loadcarrying section of the lifting lever and also pivotally connected with said load supporting saddle, there being an arcuate slot formed in said lifting lever adjacent the pivot thereof, and an anchoring pivot pin carried by 'said frame and extending through the slot in said' lifting lever, said pin pivotally' receiving the inner end of said link means.

l`2. A jack comprising a pair of spaced longi-A tudinally extending frame bars, a power unit carried at one end between said frame bars and securely xed thereto, said'power unit including a longitudinally movable plunger carried in the lower portion of said unit and extending toward the other end oi. said frame bars, a lifting lever pivotally mounted-on said frame bars adjacent said power unit and disposed with one end incontact with said plunger andthe other end extending to said other .end of the frame bars, there being an arcuate slot formed in said lifting lever, a 'pivot pin extending through said slot and supported on said spaced vframe bars, a pair of links,V

one disposed'on -each side Aof said lifting lever, pivotally mounted on said pivot pin and extend-v ing to the other end of said lifting lever, a load supporting saddle pivotally connected with the the latterand said pivot pin so as to bias the lifting lever for downward movement, the engagement vof said lifting saddle with the upper edge of said lifting lever serving to'limit the "downwardrmovement Yof the latter.

3'. A .iack comprising a frame consisting of a pair of spaced side plates, a power unit disposed at one end of said frame and including a. housing, means securing said side plates to the housing in rigid relation, certain of said securing means serving as wheel receiving axles, wheels jurnaled onv said axle means, a lifting lever mounted between said side plates adjacent said power unit, pivot means for said lifting lever 'serving as means for holding the intermediate portions of said side plates in spaced relation, and wheeled supporting means for the end of the frame opposite said power unit and including a transverse axle rigidly secured to the ends of the 'side plates and serving to maintain the latter in spaced relation. y

4. A jack comprising a frame consisting of a pair of spaced side plates having openings at opposite endsl thereof, inwardly directed apertured bosses formed on said side plates adjacent openings in the rear ends of said side bars and threaded into said housing, shouldered bushings mounted on said pair of bolts and cooperating therewith in blamping the rear ends of said side plates tosaid housing,` supporting wheel means journaled on said bushings at the rear end of said frame, and supporting wheel means for the front end of said frame including an axle disposed in the openings lat the front ends of said side plates and securelyflxed to the latter to hold them in spaced relation.

5. A jack comprising an elongated frame including a. pair of spaced side bars, a power unit vmounted at the rear end of said frame between said bars and including a housing, said vhousing comprising wall means forming a central longitudinally disposed plunger cylinder extending rearwardly from the rear end of the frame, a longitudinally shiftable plunger mounted in said lcylinder and extending therefrom at the forward of said pump handle.

tively connected to be raised when the'plunger ,is forced outwardly of the cylinder byoperation 6. A jack comprising an elongatedframe iny cluding a pair of spacedside bars, a power unit carried-at one end of the frame between the side `bars and including a casing disposedbelow the level ofthe upper portion of said side bars, a

horizontally disposed 'cylinder' mounted in the lower central portion 4oi said casing, a pump cylinder disposed in said casing at one side of said longitudinal cylinder, the space at the other side of the latter cylinder and above the same forming va sump, a pump handle mounted on the rear end of` said casing below the upper portion 'thereof and having a downwardly extending arm, a pump plunger operatively connected withsaid arm, conduit means leading from said pump cylinder to means controlling pivoted on the rear end of said casing and invto ' T the interior ofthe other cylinder, fa ram plunger disposed in said longitudinal cylinder and extending outwardly therefrom at its forward end, lifting mechanism' actuated by said ram cylinder, and generally longitudinally disposed valve the communication between said ram cylinder and said sump, said valve means extending through the pivot axis of said pump handle.

-7. A jack comprising a frame including a pair of spaced side bars, a power, unit mounted at one end on said frame between said side 'bars and including a casing, a ram cylinder disposed in the lower central portion of said casing, a pump cylinder disposed alongside said ram cylinder in the lower part of said casing, a pump handle cluding a downwardly disposed operating arm, a pump plunger movablein the pump cylinder and operatively connected with said arm, the space above and t'oone side of said pump and ram cylinders in said casing forming a liquid sump, a

'ram plungery movable in said ram cylinder and extending outwardly at the forwaid end thereof,

valved conduit means establishing communica- `tion between said sump and said pump cylinder,

valved conduit means establishing communication between said pump cylinder and said ram cylinder', conduit means directly connecting the forward part of the ram cylinder and said sump, and conduit means carried at the rear end of said ram plunger in a position to communicate with said last named conduit-means so that liquid forced into said ram cylinder passes into said sump to said conduit means whenever the ram plunger has been forced outwardly a predetermined amount, and lifting mechanism actuated by said ram plunger.

8. A jack comprising a frame, a power unit mounted at one end on said frame and including a longitudinally movable plunger in the lower portion thereof, a lifting lever pivotally mounted' on said frame adjacent to and operatively connected with said plunger, aload'supporting saddle pivotally mounted at the outer end of said lifting lever, link means extending alongside and laterally outwardly of said lifting lever and also pivotally saddle, there being a slot formed m' said lifting lever adjacent the pivot thereof, and an anchoring pivot pin carried by said frame and extending through the slot in said lifting lever, said pin pivotally receiving the inner end of said link means.

9. A Jack comprising a pair of spaced longitudinally lextending frame bars, a power unit carried at one end between said frame bars and securely xed thereto, said power unit including a longitudinally movable plunger extending toward the other end of said frame bars, a lifting lever plvotally mounted on said frame bars adjacent said power unit and engaged with said movable plunger, there being a slot formed in,

said lifting lever, a pivot pin extendingvthrough said slot and supported on said spaced frame bars, a pair of links, one disposed on each side of said lifting lever, pivotally mounted on said pivot pin and extending to the other end of said flifting lever, a load supporting saddle pivotally connected with the outer endof said lever and said links, and a pair of springs disposed on opposite sides of said lifting lever and connected with the outer end oi the latter and said pivot pin so as to vbias the lifting lever for downward movenient.

connected with said loadsupporting '10. A jack comp a frame consisting of pair of spaced side plates, a power unit disposed -at one end of said frame and including a houswheels journaled on said axle means.

l1. A jack comprising a frame consisting of a pair of spaced side plates, a power unit disposed i at one endof said framevand including a housing, separate means securing each side plate to the housing in rigid relation independently of the other side plate, certain of said securing means serving as wheel receiving axles, and wheels journaled on said axle means.

12. A jack comprising a frame, a power unit mounted at one end of said frame and including a housing, said housing comprising wall means forming a central longitudinally disposed plunger cylinder having a closed rear end extending from the rear end of the housing, a longitudinally shiftable plunger mounted in said cylinder and extending therefrom at the forward end of the housing, a pump handle pivotally mounted on the rearwardly extended portion of said cylinder,

-pump mechanism carried by said housing operathreaded openings at opposite tively connected with said pump handle, a sump at least partially surrounding said cylinder, a. bore extending from said cylinder to said sump in a line that intersects the pivot axis of said pump handle, and valve controlling means carried by said handle and including a part intersecting said pump handle axis.

13. In a jack, a hydraulic power vunit including a casing, horizontally disposed ram cylinder mounted in the vlower central portion of said casing, a pump cylinder disposed in 'said' casing alongside said longitudinal cylinder, the' space at the other side of the latter cylinder and above the same forming a sump, a pump handle pivotally mounted on the rear end of said casing having a downwardly extending arm, a pump plunger operatively connected with said arm, a needle valve controlling the liquid ow from said ram cylinder to said sump and disposed in a position with its outer end in the pivot axis of said handle, and 'means carried at the upper end of the handle and connected with said outer end of the needleAva-lve for actuating the latter.

14. A :lack4 comprising a frame consisting of a pair ofspaced side plates having openings at one end; a power unit including a housing ttng in between said side plates, bolt mea'ns securing said side plates to said housing including a pair of transverse bolts disposed in the openings in said side bars and threaded into said housing, bushings mounted on said pair of bolts and cooperating therewith in clamping said side plates to said housing, and supportingwheel means journaled on said bushings.

15. Av jack comprising a frame consisting of a pair o spaced side plates having openings at one end, a power unit including a housing fitting in between said side plates, said housing having sides and said openings being enlarged atthelr outer portions, bolt means securing said side plates to said housing including a pali of transverse bolts disposed in the openings in said side plates and threaded into said housing openings, bushings mounted on said pair of bolts `and extendingJ into the enlarged portions of said housing openings, said bushings cooperating with said pair of bolts in clamping 'the side plates to the housing, and

supporting wheel ings.

V16. A jack comprising a frame consisting of a means journaled on said bushpair of spaced side; plates having openings atl the enlarged portions of said v,housing openings,

the shoulders on said bushings being disposed against the outer faces of said side plates and said bushings cooperating with said pair of bolts 1 in clamping the side plates to said housing, and

supporting wheel means journaled on lsaid bushings.

17. In a hydraulic powerunit including a casing, a ram cylinder disposed therein and open at its forward-end, a pump cylinder disposed alongside said ram cylinder in said casing, apump plunger movable in the pump cylinder, the space above and to one side of said pump and ram cylinders in said casing forming a liquid sump, a ram plunger movable in said ram cylinder and extending outwardly at the forward end thereof, packing for sealing the outer end of the ram cylinder and the ram plunger, conduit means forward of said packing and` leading into communication with the forward portion of the sump, and conduit means carried at the rear end of said ram plunger in a position to communicate with said rst named conduit means so that liquid forced into said ram cylinder vpasses into said sump through said conduit means whenever the ram plunger has been forced outwardly an amount sufficient to bring the ram cylinder conduit means outside said packing and into registry A with said rst named conduit means. Y

18. A jack comprising an elongated frame including a pair of spaced side bars, a power unit carried at 'one end of the frame between the side bars and including a casing disposed below the level of the upper portion of said side bars, a horizontally disposed cylinder 'mounted in the lower central portion of said casing, a pump cylinder disposed in said casing at one side of said longitudinal cylinder, and a sump, a pump handle mounted on the rear end of said casing below the upper portion thereof and having an arm, a pump plunger operatively connected with said arm, conduit'means'leading from said pump cyli der to theA interior of the other cylinder, a ram plunger disposed in said longitudinal cylinder andextending outwardly therefrom at its forward end, lifting mechanism actuated by said ram cylinder, and generally longitudinally dis, posed valve means controlling the communicavtion between said ram cylinder and said sump,

said valve means extending through the pivot axis of said pump handle;l

19. A jack comprising an elongated frame including a pair of spaced side bars, a power unit mounted at the rearend of said `frame between said bars and including a housing fastened to said side bars,A said housing comprising wall means forming a generally longitudinally disposed ram cylinder having an open end, a pump cylinder at one side of said ram cylinder, and

a sump disposed generally above said pump cylinder, a longitudinally shiftable ram mounted in said ram cylinder and extending therefrom at one end of the housing, a pump plunger in said pump cylinder, high pressure conduit means leading from said pump cylinder to the forward end of said ram cylinder for conveying operating fluid under pressure from said pump cylinder to said ram cylinder for shifting said ram outwardly of the ram cylinder, a secondconduit means leading from said ram cylinder into said sump, a low pressure duct leading substantially directly ver-l tically from the closed `end of said pump cylinder to said pump, and lifting mechanism carried by said frame and including a lifting lever directly connected to the outer end of the ram so as to be raised'when the' ram is forced outwardly of the ram cylinder by' operation of said pump plunger.

20. A jack comprising an elongated frame including a pair of spaced side bars, a power unit 'mounted at the rear end of said frame between said bars and including a housing fastened to said side bars, said housing comprising wall means forming a generally longitudinally disposed ram cylinder having an open end, a pump cylinder at one side of said ram cylinder, and a sump4 having an open upper portion, a closure plate for closing the latter, a longitudinally shiftable ram mounted in said ram cylinder and extending therefrom at one end of the housing, a

'pump plunger in said pump cylinder, a first conduit means leading from said pump cylinder to the forward end of said ram cylinder, a second conduit means leading from said ram cylinder into said sump, each of said conduit means having a section the axis of which extends through the open portion of the sump, and one of said conduit means constituting a relief passage providing for flow of fluid from the ram cylinder, a relief valve controlling the flow through the relief conduit means andthe section thereof leading upwardly and rearwardly into said sump, and lifting mechanism carried by the frame and actuated by said ram.

21. A jack comprising an elongated frame including a pair of spaced side bars, a power unit mounted at the rear end of said frame between said bars and including a housing the upper portion of which is substantially `on the same level as the upper edges of said bars, said housing comprising wall means forming a sump and a'ram cylinder'having an open forward end, a longitudinally shiitable ram mounted in said cylinder and extending therefrom at the forwardend of the housing, said housing also including a pump cylinder openV at its rear end and closed at its forward end, a pump plunger movable therein, a generally transverse duct leading directly from the forward end of the pump cylinder to saidsump, a passage leading from said duct to said ram cylinder, lmeans for forcing said pump plunger forwardly to direct fluid under pressure into the ram cylinder for forcing the forward end of the ram outwardly of the ram cylinder, a valve-controlled relief conduit leading from said ram, cylinder generally upwardlyk into the sump, and lifting mechanism carried by said frame and including a lifting lever pivoted on the frame and dlrectly connected to the forward end of said ram.

EDWARD M. PFAUSER..

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