US1590849A - Lifting jack - Google Patents

Description

. June 29 1926.

L. NlLsoN LIFTING JACK Filed Dec. 22', 1924 2 Sheets-Sheet 2 www 4. Hun

,47'ToeA/EYS I Patented dune 29, 1926i LEONARD NILSON, OF WAYZATA, MINNGTA.

LIFTING JACK.

j Application med ncember 2z, 1924. Serial No. ariane.y

This invention relates to improvements in lifting jacks of the hydraulic type such as -are' commonly employed for lifting the wheels of an automobile and the like, and 5 more particularly is an improvement onv the form of jack shown in my prior pending application, filed November 27, 1922, Szrial #603,661

The object of this invention is to provide a hydraulic lifting jack having anoperating handle pivotally connected to the lower portion or base thereof so` that the displacement pump mounted in the handle may be operated at any angle with reference to the jack.

A further object is to provide a jack having a jointed handle pivotally connected thereto, said handle comprising an auxiliary chamber or reservoir wherein the displacement pump is reciprocally mounted, and the pump being provided with a yieldably mov-A able take-up means adjacent its upper end portion which functions to automatically compress the packing against the pump rod to prevent leakage therethrough. l

' A` further object is to provide a jack of the above character having 'an inverted packing box provided in the cylinder head, and having means provided on the piston 3O'rod thereof adapted 'to engage the packing nut when the ypiston is raised to the limit of its upward movement, 'so that when the piston rod is rotated within vthe cylinder of the jack the relative position of. the packing nut may be adjusted in the cylinder head,

thereby to compress the acking against the piston rod to prevent lea rage.

. A further object of the invention is to pro-i vide such a jack having allof its valves and 40 associated -parts removably mounted in the lower pivotal connection between the handle,

and pump so that the valves may rea'dilyj be removed'from the jack for cleaning or re'- placement without having to remove the handle from the jack.

Other` objects of the invention will more fully appear from the following detailed de scription and the accompanying drawings and will be pointed out 1n the annexed claims.

In the drawing, there has been disclosed a structure designed to carry out the objects of the invention, butit istobe understood j that .the invention is.' not confined to the exact features 'shown as various Changes `lower end of the piston rod.

ma be made within the scope ofthe claims whlch follow. l i V 7 Inthe accompanying drawings forming a part of this specification, i Figure 1 is a cross-sectional viewjo'fthe 60 improved jack showing the piston rod and piston in lowermost orpnormal position;

Figure 2- is a cross-sectional view o'nthe line 2 2 of yFigure 1 showing the simple construction of' the valves mounted in the 6b pivotal connectionbetween the handle and base of the jack; Fi ure 3 is a verticalv sectional view on 'the line 3--3 of Figure 2, the upper portion of the jack being shown in elevation' 'I0 Figure 4 is a cross-sectional view through the upper portion ofthe operating handle showing the. preferred means provided for demountably connecting the upper sect-ion of the pump handlev to the relatively larger lower handle section; I'

Figure- 5 is a cross-sectional view on they line 5-5 of Figure 1 showing the means pro'- vided for limiting the downward movement of the pump rod. 80 litigareA 6 is an enlarged detail sectional view of the upper end of the pump section of the handle. j The jack shown in the accompanying drawings comprises a hollow tube or cylin- 35 der 6 suitably Vmounted in a raised boss 7 integrally fprmed on a suitable base 8 as shown in Figure 1. The cylinder 6 may be secured to the boss 7 by such means: as the threads 9. A piston rod 11, having a lifting head 12 secured to the upper end thereof, is

reciprocally mounted within the cylinder 6.

A piston head is secured to the lower end of the piston rod. This-piston head preferably comprises a disk-like member 13 where- 95 on the usual tleather cup or packing ltis mounted as shown. ,A washer 15 is seated l on the llower central portion of the packing adapted to be engaged by a flanged nut 16 received Ain threaded engagement4 on the 100 The vianged nut-16 is provided with a series of apertures 17 through which the` pressure fluidy may enter the inside of the piston and, utwardly force the vertical wall of the packing against thewall of the cylinder 6, thereby positively preventing any of the Huid from ,escaping around the acking when the piston is being raised to lift a load. `The' peripheral flange 0f .the nut 16 is also arranged to overhang 110 the loweredge of the`packin f cup thereby providing a longer bearing or the piston rod when being raised and also preventing the lower edge of the cup from becoming damaged in use. lt also functions to prevent the iiuid from inwardly forcing the flange o1" the packing, and escaping thereby tothe upper portion of the jack.

A feature of this invention resides in the novel means provided at the upper portion ot' the cylinder 6 to prevent leakage ot the fluid therethrough when the `jack is iii operation. As shown in Figure 1. a cylinder head or cap 18 having a tapered scat 19 mounted upon the upper end of the f yliuder (3 by means of suitable threads 2l. The upper inner corner ot the cylinder wall (i is correspondingly tapered to" provide a seat tor a suitable packing washer or gasket 22. Vlien the cap 18 is rotated on the threads 21, the gaske` 22 will be tightly' compressed between the tapered scat 19 ol the head and the upper end ot the cylinder wall thereby positively preventing any leakage ot fluid therethrougln The cap 18 also provided with au inverted lstutiing-box depending within the upper end ot the cylinder (5. As

shown in Figure 1,'this stuiIing-box preterably comprises a hub Q3 having a conical seat 24 at the upper end tliereotl against which the usual packing 25 is lcompressed by means ot an annular ring 26 engaged by a suitable compression spring 27. The other end of the spring 27 is seated against a packing nut 28 which is adjustably mounted in threads 29 provided in the-lower end ot thc hub 2?). l

The. means provided for adjusting the position of the packing nut 28 to tighten or compress the packing 25 preferably consists in providing` suitable slots or grooves 31 in the lower face ot the nut adapted to receive the oppositely pi'ojesting end portions of a pin 32 mounted in the lower end of the piston rod adjacent the disk-like member 13. ll'hen it is desired to change the relative position 'of the packing nut 28 the operator will raise the piston rod until the ends of the pin 32 engage the slots 31 in the nutl at'ter which the nut may readily and conveniently be rotated and adjusted-by simply rotating the upper end of the piston rod. Yhcn the packing has been tightened to the desired degree to prevent leakage around the pist on rod, .the packing nut will be frietionally retained in adjusted position by means of the spring 27 which'tends to downwardly force it against the threads 29. It 4will be noted that when the piston rod is in loweimost position, as shown in Figure 1, and the head 12, is bearing against the cylinder head or cap 18, that a space will be provided between the piston and the bottom wall of the cylinder, formed by the base. This space is to provide clearance for the duid so that it may be forced under the piston when it is desired. to raise it.

Another feature of this invention resides in the novel construction of the pivotal connection between the pump handle and the `base of the jack. As shown in Figure 1, the

lower portion ot the operating handle is preferably constructed of a relatively larger l `the lower pivotal connection of the handle.

and which will be subsequently described. The tubular member 33 has its lower end lixedly mounted in a hub 3T of a T-shaped head 3.2 having oppositely extending tapered end portions 59 and 4l, as particulaily showniii Figure rlhe end portion 39 is mounted in a correspondingly tapered bearing 42 provided `iii a hub 43 integrally formed on the base plate 8 as shown. The opposite end portion 4l is mounted in a tapered bearing 44 provided in a sleeve 45 which is adjustably mounted in a hub 4G. The inner end ot the sleeve 45 is threaded t0 receive a lockmit 4T whereby the sleeve 45 may be axially adjusted within the hub 4G so as to provide leak-tight joints between thc tapered extensions 39 and 41 and their correspondingly tapered seats 42 and 44, respectively. By means ofthe nut 47, the pivots may also be adjusted so as to provide the proper friction to suit the operator. A port 48 is provided in the T-sliapcd head 38 and leads from the chamber 36 of the pump handle` to a duct 49 provided in theend portion 139 ot the T-shaped head. A port 51 is provided in the boss 43 of the base 8 and leads from the.duct 49 to a passageway provided adjacent the outer wall of the c vlindei' and having its upper end in communication with the upper end of the cylinder by means ot' apertures 53 and 54. Thus it will be seen that the upper portion of the cylinder will always be in direct communication with the auxiliary reservoir or chamber 3o.

`The valve mechanism provided 'for controlling the return flow of the fluid from beneath the piston to the upper portion of the cylinder and the auxiliary reservoir, preferably 'consists of a pair of ball' check valves which are operatively inount-ed in the T- shaped head 38 and the sleeve 45, as is clearly shown in Figure 2. As here shown, the tapered end portion 41 of the T-shaped head is provided with a relatively larger izisA that when the pump rod is downwardly moved to the limit of its downward 'movement,.in the lowering operation of theja'ck, thelower tapered endportion 58 thereof will engage the ball and unseat it to allow the fluid to retuin from beneath the piston to the upper portion of the cylinder, and to means provided for opening or unseating the' outer valve 59. when. the inner valve 57 1s -I'Jaratively stronger than the inner spring 67 so that the ball valve 59 will normally be 'held against the seat 61 againstthe .tension 40 vthe auxiliary reservoiror chamber 36. A'

similar valve 59 is mounted in the sleeve 45 andisy-ieldably held against a seat 6l by means of a compression spring 62, preferably 1 mounted in 'a hollow cap' 63-rece1ved in threaded engagement in the end of the sleeve 45. A suitable gasket 6,4, preferably of as-v bestes, is interposed between the flanged head of the cap 63 and the end of the sleeve to provide'a. tight .joint therebetween. The

opened by downward movement of the pump rod 35 preferably consists of .a triangular. member 65 which-is interposed between the.

two valves in the bore of the end portion 41.0f the T-shaped head. This triangular member has a reduced end portion 66 pro' vided onone end thereof uponwhich a coiled compression spring 67 is mounted having one end'bearing against the adjacent end of .the

triangular member 65 and the other end. bearingagainst the ball check valve 59..l It

is to be understood that the spring 62 is com of the spring 67. vWhen in normal closed position, as above described, the spring 67 will yieldably retain the inner check valve 57 in closed position lagainst the seat.56 as shown in Figure 2. It is also .to be understood that the overall length of the triangular member 65 and its reduced end portion 66 is less than l the shortest distance between the two valves 57 and 59 to be opened vagainst the tension of the spring 67 and without unseatingfthe valve 59. each time the pump rod 35is upwardly drawn to till the inner tube 34 with iluid, which action-of the'pump rod will necessarily cause .the valve 57 to open.

When the pump rodis downwardly moved to force the fluid under the piston'the valve 57 will retain its closed position andthe -fluidwillpassthereby and around the openings between the triangular member. 65 and the bore 55 and against the outer check valve. 59. The pressureof the fluid againstjthecheck valve 5 9 will cause it to open and allow the fluid to be forced into a port 6 8 which is in inder through a Vtube 69 and duct 71. When the downward stroke of the. pump rod 35 has been completed and it 1s again'outwardly drawn in the operation of the vnext stroke, the valve 59 will be closed by the spring 62 and the valve 57 will again be opened by the suction of the pump rod against thc tension of the spring 67. vWhen it is desired to lower the jack, the pump rod 35 will be moved to the limit of its downward stroke, thereby causing-the beveled 'face 58 thereof to engage the valve 57 and unseat it against the tension ofthe spring 67.` Such unseating of theI valve 57 will cause the triangular member 65 tb be axially moved `within the bore 55 until the terminal ofthe-reduced end portion 66 will engage the v alve' 59 and open it against the 4tension of they spring 62. When the two valves havethus been" opened the' fluid will return from beneath the piston throughthetube 69,"po1't 68,l by the open valve 59, through'the -bore'55 and by the open valve 57 g thence throughthe duct 49,

`port51, vpassageway 52 and `into the upperportion Vof'the-cylinder. A -portion of the i fluid will also be returned to the auxiliary reservoir or chamber 3 6 through the'- port 48. 'Assoon as theipump rod isl upwardlyv drawn out of. engagement with the "check valve '57, the two' lvalves will again, vautomatically-*bemoved. into yclosing position.` Referring to Figure 2, it will be seen that should the lvalves become inoperative as a result of dirtandgrit orfrom wear, they may readily and quickly'befremoved from their .seats y:tor cleaning'or' renewal, by simply unscrewing the cap 63-and` slightly tilting the` jack until they drop out oftheirseats.v It

willalso be seen vthat when the valves are l opened, the valve 57 will beo'pen'edrst.

against -the tension of the spring 67 ,'.therel being substantially vno ba'cli pressure inthe bore 55.l 'Such movement of thevalve 57 will cause the triangular member 65 to be duced end portion 66 contacts with the valve vmoved towards the valve 59 until' thev rei riolthe valve 59'is .opened the fluid may freely return to thenpper portion of the cylinder and the auxiliary reservoir. Inactual operation of the jade-.a has been: found 'that should the valves become stuck from dirt and grit, they. may .smetimesfbe operative by simply tappingthevalve 57 with theend 1 58 of the plunger rod, thereby 'eliminating the necessity `'of having to remove the valves for cleaning. A

-A hollow sleeve72 is suitblylsecured to the upper end fofthe. tubularmember 340i' the pump handle. .b y -sinhjneans as brazing `or welding.; Referring' to Figure .6,'itwill be noted that the upper en d ofthe relatively smaller tube 484 which forms the-barrelor the lower 'end thereoffby means of v'threads' i j cylinder for the pump rod.3 5 Ais secured' to communication with the bottom of the cyl- 73. The upper end ofI the sleeve 72 is'` provided with a relatiyely larger bore 7 4 adapt-.

ed to receive one end of the handle section 75 as shown in Figure 1. An aperture 7G is provided in the wall of the handle section 7 5 adjacent its lower end and this aperture 1s adapted to receive a locking pin 77 ures l and 6. The ends of the band 78 are preferably formed to overlap each other as shown in Figure 4 solthat when it is desired to remove the upper handle section 75 from the lower handle section 33, the operator will press the overlapping ends '79 of the band towards and against the wall of the tubular member 33, thereby7 causing the pin 77l to be outwardly moved to the position shown inv dotted lines in Figure 4, out of engagement with the aperture 7 (i provided in the handle section 75. The handle section 75 may then'readily be disconnected from the lower handle section after thefupper end 8l of the pump rod has been unscrewed from vthe head 82 secured to the upper end of the pump rod 35. A threaded bushing 83 is mounted in the sleeve 7 2 and upwardly projects into the enlarged bore 74 provided at the upper end of the sleeve. An open ended slot or opening 84 is provided in one side of the bushing 83 .adapted to receive an elongated lug or extension 85 provided on one side of the head 82 of the pump rod and depending therefrom in axial alignment with the pump rod. In the operation of the pump rod 35, the lowerend of the lng 85 will engage the face 86 of the bushing 83, thereby preventing the lower end ofv the pump rod from contactingr with the ball check valve 57. lVhen it is desired to unseat the valves to release the Huid from beneath the piston, the pump rod A8l will be rotated by means of the hand grip 87 until the depending lug 85 is brought into registration `with the open vended slot v84' inthe bushing 83, after which the pump rod may be moved to the limit of its downward movement into engagement with the valve 57 which willbe opened thereby. It

is to be understoodithat when the lug 85 is lower pointed end of the pump rod froml becoming damaged from contact with the opposite side of the bore a stop washer 80 is preferablyy mounted in the bottom of the enlarged bore 74 of the hollow sleeve 72. This stop washer is preferably provided with an inwardly projecting lug 88 which is fitted into the .elongated opening land the pump mounted therein.

or slot 84 as clearly shown in Figures 4 and 5. When the pump'rod is downwardly moved to unseat the valves,the lower face of the lug 85 will engage the lug 88 of the washer 80, thereby preventing the rod from inserted into the open .end of the slot 84,-

in which position it may be downwardly moved to unseat the two valves.

Means are also provided in this novel jack to positively prevent any leakage of fluid from the upper end of the handle section-33 Such means preferably consists in mountinga packing washer 91 within the bore of the .hollow sleeve 72 and 'in abutting relation to 'the upper end of the tube 34. This packmgwasher is provided with a projecting inclined face 92 which is adapted to engage the usual packing 93 and outwardly force it against the wall of the sleeve 72. A packing washer 94 is also mounted .in the sleeve 72 to provide a backing for the packing 93 as shown in Figure l. This washeris provided with a recessed face 95 which is preferably correspondingly inclined and functions `to force the packing inwardly against the pump rod 35. A compression spring 96 is interposed between the packing washer 94 and a flat washer 97 which functions to compress the upper packing 98 against the lower inclined face of the threaded bushing 83. By means o f this novel construction, it will be seen that any pressure built up within the hollow tube 34 around the pump rod 35 will act directly against the, lower pack.-

ing washer 91 which will tend to upwardly move it against theV packing 93. 'Such action of the packing washer 9 1 will causethe lower portion of the packing t0 be outwardly forced against the walls lof the sleeve i 72. Conversely, the upper end of the packing 93 will be forced inwardly against the pump rod by the action of the inclined face 95 ofv the washer 94, thereby preventing any leakage of fluid around the pump rod or between the packing and bore of the sleeve 72. Upward movement of the packing washer 94 will be prevented by the action of the `spring 96 which also functions to retain'the upper packing 98 u'nder constant pressure. Should any fluid, however'. escape'by the lower packing 93, then it will enter into the chamber wherein the spring 96 is mounted vand from 'which chamber it will be returned to the auxiliary reservoir 36 through `suitlower flange of the vsleeve 72 through. which any fluid being. returned to the chamber 36 reservoir 36. A filler plug102 is provided in the tubular handle member 33 'adjacent its lupper end by means of which the jack may .be supplied or filled with a suitable operatingfluid., f"

I Means are also provided to prevent an eX- cessive pressure .from being built up within -the lower portion of the 'jack -in the lifting .I .operation thereof. Such means preferably consists inthe provision. 'ofV the port 54 which is .located as `shown in 'Figure 3 and 'functionsvto allow the fluid pumped under,

the piston `to be returned to the auxiliary reservoir or chamber' 36 when the piston has reached a 'predetermined height.y

-fI claim as my'inventiony l. A liftingjack comprising a base, va

' pump barrel and plunger, a,k handlehaving 1 'a head' journaled in sind base and proviied v with a duct leading to said'barreLvalve in said duct controlling the delivery of inelastic fluid to said barrel, and means permitting the removal of saidvalves from said duct Withoutremoving said head from its bear.-

ings in said' base.-

2.` Ay lifting jack comprising a base,

' pumpbarrel and plunger, a handle having a head journaledy in said base and provided witha duct leading to said barrel, valves in saidduct controlling -the 'delivery of inelas- -ticiuid to said barrel, and means permitting the removal of saidl valves from said duct without removing said head from its bearings in said base, said means "comprisl ing a coupling sleeve having aremovablef 3.- A, lifting jack comprising a base, -a pump barrel and plunger therefor, a handle having a T shaped head,` 4a "pump handle therein, a sleeve adjustablymounted in said,

base and having a tapered seat therein to e V`having a T-sha-ped .headjournaled' in ,said

,receivea correspondin' ly shaped end of said head, andpermit sai handle to be tilted,

`said head and sleeve havingan inelastic iuidduct communicating with' said barrel. and valves for-controlling the fiow of inelastic. fluid` through said duct, the' adjustment of said sleeve increasing o r decreasing its frictional contact with said head to obtain the desired 'resistance to the movement 'of said handle.

- 4.- A lifting pump barrel an plunger therefor, a handle base,a couplingisleeve provided aty oneend 'of said head and seated thereon and having f a suitable takeeup devicef said head and sleeve'having an inelastic fluid duct therein,

4said barrel,

ackcomprising a lbase, a;

Iand-valves -for said duct, a tube and cou- -saidy sleeve by saidtalreup device, anda cap removably mounted in said sleeve and ypermitting access to said duct and valves. through the apertures 99 may return to the 5. A lifting jack comprising a barrel, a plunger. and rod therefor, a supporting base for .said barrel havin@ hubs thereon,` one of said hubs having la lbore and the Vother a l taperediseat, a sleeve fitting within said bore seats, said sleeve and head having ducts therein and'valves for said ducts. i

6. A lifting-jack comprising a barrel having a base, a pluri er' and rod/thereforin a handle mounted on said base and havingan inelastic luidjreservoir and..`

`supply andreturn' ducts leading to sar."w u-barrel, 'and valves for said ducts' controlling l `the feed and return of'inelastic fluid, awreciprocating pump rod mounted insaid 'handie adapted to control the opening and closs ing Iof said feedy andreturn` valves, `and means for positively unseatingsaid feed valve whensa-id return valvevyis actuated by.

'theengagement of said pump rod therewith.

l' 7 A lift-ing' jack comprising a barrel hav ing' a suitable base -andA 'plunger and rod,

therefor, a-handle' mounted onsa-id base and having an inelastic'uid reservoir therein,

andsupply and returnA ducts communicat-V 'ingcwith'said reservoir and with said'barrelv above and below said plunger respectively,

`said ducts ha'ving seats and valves therefor,

ino

awthrust memberA interposed betvveen said,

valves and normally out ofV contact 4withsaid lsupply valve andghavingme'ans for yielding-u ly holding said returnvalve normallyeto its" j seat, Aa'pumprodoperating in said handle, the Vdownward-"stroke of s aid rod opening said supply valve land vthe upward ,stroke -thereof opening said return valve, said rod having means,` when moved into engagement with. said return valve,for'forcingl it oft-its seat and moving said thrust member lengthwise toy positively unseatv Said .supply valve. and therebyh relieve the y pressure "on said .plunger and`.allow it-,to` drop in said v bar-re 8. A'lifting jaclrcomprising a pump barrel :having a plungerfand rod therefor, ya

head for said barrel havinga stuffing-box dependingwithin' said barrel and wherein said rodis islidab'le, saidbopxghaving ataper'ed seat andp'acking therefor, an adjust- `ing nutfor-s'aid packing and said rod havtherein and in which said rod is slidable,`

a packing for said box, an adjusting nut therefor having a transverse slot and a pin mounted in said rod toenter said slot for turning said nut when said rod is rotated.

10. A lifting jack comprising a barrel, a plunger and rod therefor, a handle'l connected with the base of said barrel and having an inelastic fluid duct therein communicating with said barrel, a return valve in said duct, a pump rod mounted in said handle to normally reciprocate therein and force the inelastic fluid pressure into said barrel under said plunger. and also having a movement to unseat said valve, nieans'normally preventing sufficient downward stroke of said pump rod to unseat said valve but permitting such downward movement when said rod is rotated to a predetermined position.

11. A lifting jack-comprising a barrel, a plunger and rod therefor, aliandle connected with the base of said barrel and having an inelastic Huid duct therein communicating with said barrel, areturn valve in said duct,a pump rod mountedl in said handle to reciprocate therein and force the inelastic fluid pressure into said barrel under said plunger, continued movement of said rod unseating said valve, means normally limiting the downward stroke of said pump rod to prevent unseating of said valve but permitting such downward movement when said rod is rotated to a predetermined position, said means comprising a bushing mounted in said handle and having a longitudinal slot therein, and a lug on said pump rod normally contacting with the end of said l bushing but adapted tol enter said slot when lastic fluid duct communicatin said rod is rotated.

12. A lifting jack comprising a pump barrel, plunger and rod therefor, a handle connected with said barrel and having an inebarrel beneath said'plunger, an a valve in said duct for controlling the flow of inelastic fluid from said barrel to said handle, a pump rod mounted in said handle and having a beveled lower end adapted to engage and unseat said valve, and means for limiting the downward stroke of said pump rod and preventing damage to the beveled end thereof. Y

13. A lifting jack comprisingl a pump barrel, plunger and rod therefor, a handle connected with saidbarrel and having an inelastic Huid duct communicating with said barrel beneath said langer, and a valve in said duct for controlling the flow of inelastic Huid from said barrel to said handle, a

ump rod mounted in said -handle and hav.- mg a tapered lower end adapted to engage and unseat saidvalve, and means for limiting the downward stroke of said pum rod and preventing damageto the tapere with said end thereof, said -means including a stopA washer having an inwardly .projecting lug in the.A

path of a depending lug on said pump rod.

14. A lifting jack comprising a barrel having a suitable base, a plunger and rod therefor, a handle mounted on said base and comprising outer and inner tubular members with a space between them forming an ine'- lastic fluid reservoir, said base and handle having ducts therein communicating with said barrel and with saidvinner and outer tubular members, and valves for controlling the flow -of fluid through said ducts, a sleeve forming a continuation of said inner tubular member, a pump rod mounted to slide in said sleeve and inner tubular member, a packing box for said pump rod provided in 'said sleeve and ports in said sleeve for conducting leakage in said stalling-'box to saidV l'luid reservoir.

15. A lifting jack comprisinga barrel and' boxes comprising packing and washers therefor encircling said pump rod within said sleeve and having a space between them .and a compression spring in said space separating said washers, the wall of said sleeve having ports between said washers leading from said space to said reservoir through which leakage around saidpacking is re turned to said reservoir.

16. A `liftin jack comprising a barrel having a Asuita le base, a plunger and rod for said barrel, a handle mounted on said base, a tube in said handlecommunicating with said barrel, a sleeve connected with said tube, a pump rodslidable in said tube and sleeve, packing washers on said rod in said sleeve and having opposing convex and concave surfaces, a pacln'ng between said washers adapted t'o slide on said rod, que of said washers being exposed to pressure in `rod mounted to slide in said sleeve and tube, a packing within said sleeve exposed to the pressure '1n said tube when said rod is `thrust ownwardly, said packing being adapted to said barrel, a handle mounted on said base,

Vslide up and grip said rod, and a spring on said rod within said sleeve for yieldingly resisting such .upward movement of saidl packing.

1S. A lifting jack comprising a barrel.

and base therefor, a plunger and rod vin member forming afcontinuation of saidtube,

p a pump rod mounted to slide in said sleev'e and tube, two sets of packing washers and packingwithin said sleeve,a washerof oneset being exposed to the pressure in said tube when said rod lis operated, and adapted to'slide under such pressure on said rod, a spring on said rod between said sets of packing anclnormally resisting such sliding movement, and said second packing serving to prevent the'inelastic fluid from leaking out around said pump rod when said handle is in horizontal position.

19. A lifting jack comprising a barrel and base therefor, a plunger and rod in said barrel, a handle mounted on said base, an inelastic fluid reservoir provided in said handle and having a duct connection with said barrel, a sleeve within said handle, a pump rod adapted to reciprocate in said sleeve, tWosets of packing washers and packing therefor encircling said pump rod within said sleeve, a compression spring interposed between the setsof packing to resist movement thereof on said rod, and a A bushing mounted in said vsleeve Afor adjustment of said packingsets and said compression spring.

y 20. A lifting Jack 'comprising a barrel and base therefor, a plunger and rod for said barrel, a handle mounted on said base and having an inelastlc fluid reservolr and duct communicating with said barrel,a valve in said duct, a pump rod mounted to` re-1 ciprocate in said handle and having an endV to unseat said valve, a'sleeve "and packing therein for said rod insaicl handle, a slotted bushing' having threaded engagement', with said sleeve for adjusting said packing, said rod having means normally limiting its `stroke' but adapted when rotated to a predetermined position to enter the slot in said bushing and allow said rod to unseat said*v valve, and alocking bolt 'adapted to enter the slot insaid bushing and hold it in positioi to allow the valve release stroke of said ro 21. lA lifting jack comprising a barrel' and base therefor, a plunger `and rodin said barrel, a handle mounted on said base and comprising a tubular member having an inelastic fluid reservoir therein vand a duct connection withv said barrel, a pump, rod

mounted in said handle, a telescoping handle extension for the outer end of .said tubular member, a pump rod extension mounted in said handle extension and having means for connection with said rod,.and a snap fastening device for iremovably mounting said handle extension on the outer end of said tubular member. i

22. A lifting jack comprising a base, a piston cylinder and piston therein on the base, aplurality of bearings on the base, a pump including .a reciprocating plunger with its base pivoted in said bearings and connections from the pump through the base to the upper and lower part ofthe piston chamber, having valves therein to properly control the How of fluid from said pump to the upper and lower ends of said piston chamber.

Inwitness whereof, I have hereunto set my hand this 19th day of December, 1924.

LEONARD NILSON.

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