US2463797A - Jack - Google Patents

Description

March 8, 1949. H E, PAGE 2,463,797

VJACK Filed March 6, 1944 2 sheeps-shet 1 March 8, 1949. H, E PAGE 2,463,797

JACK

Filed March 6, 1944 2 Sheets-Sheet 2 3 E my Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE JACK Herbert E. Page, Pasadena, Calif.

Application March 6, 1944, Serial No. 525,260

13 Claims.

vide, in such a jack, resilient means for disengaging the mechanical lifting means from the work-lifting piston.

Another object is to provide in such a jack a novel collar for releasably engaging and moving the piston into initial contact lwith the work to be lifted.

Still further advantages are provided by my invention and will become apparent from the following detailed description of preferred embodiments which I have chosen for the purpose of explanation. I wish it understood, however, that I do not intend to conne the invention to the precise details of structure and association of parts now to be set forth because the invention is susceptible of being carried out in other physical embodiments which the following explanation will suggest to those working in the art.

In connection with the following description I shall refer to the accompanying drawings, in

which:

Fig. 1 is a cross section taken on line I.'| of Fig. 2;

Fig. 2 is a vertical section taken on line 2--2 of Fig. 1;

Fig. 3 is a front View with the front wall removed, being shown partly in section;

Fig. 4 is a top plan view of a modified form of my invention;

Fig. 5 is an enlarged medial vertical section of the jack of Fig. 4, some parts being shown in elevation;

Fig. 6 is an enlarged front 'elevation of the jack of Figs. 4 and 5;

Fig. 7 is an enlarged fragmentary section showinga modied form of lifting collar; and

Fig. 8 is an enlarged fragmentary section showing a modified form of connecting rod.

Referring first to Figs. 1, 2 and 3, I show a body comprising a base 5, side walls 6, and cover 1; the side Wall being of oval cross section and secured to the cover and base by means of screws 8, although, of course, the body may be formed in other manners well-known in the art. A cylinder IU has its bottom, exteriorly threaded end Illa threadedly mounted in a corresponding recess in thebase 5 and a cylinder 2 l2 providing a fluid reservoir R is mounted in the body, the cylinder l2 having its threaded reduced lower end I2a threaded into a recess I5 in the base, and presenting a port I6. A threaded plug I1 closes the top end of cylinder I2, the plug having a port l`8 to atmosphere.

A piston 30 having an interiorly threaded upper end portion 30a is reciprocally disposed in cylinder I6, there being a core 3l threadedly mounted in the portion 36a for extension purposes. The top end of core 3l provides a workcontacting pad 32, the piston being protractable and retractable through an opening 35 in cover 1. A guide ring 31 is provided between the cylinder interior and piston portion 30a and a seal ring 38 is provided in an annular recess in piston 30.

A second cylinder 40 is provided in the base, said cylinder being of relatively smaller diameter than cylinder l0 and having mounted therein a piston 45 whose lower end forms with the cylinder a pressure-generating chamber 46. Piston 36 forms with cylinder l0 a main pressure chamy ber 41.

Chamber 46 communicates with the reservoir through ports 50, 5I, 52 formed in the base and port I6 formed in the neck I2al of the reservoir cylinder, said communication being controlled by a ball check valve which is normally maintained seated towards the reservoir by a coil spring 56 disposed around a slide bar 51. Thus on the up or sunction stroke of piston 45v in chamber 46, the vacuum created in that chamber will dra'w fluid from the reservoir past valve 55.

Chamber 46 communicates with chamber 41 on the down or .pressure stroke of piston 45 through a port 60 when the pressure in chamber t6 is sufficient to overcome the pressure of a spring 6:2 which normally urges a ball check valve 6I seated towards chamber 46.

An operating shaft is journaled in a bifurcated boss 68 carried by the base, being oscillated by a lever 66. Oppositely disposed arms 69, 10 are secured, as by splining, on the shaft 65 arm 69 being pivotally connected to the bifurcated top end of piston 45 by a link 1I and cross pins 12.

A collar 15 having a diagonal bore 16 somewhat loosely ts over piston 36a, said collar being urged into a position of rest horizontally against the `top end of cylinder I0 by springs 11, 1B, in which` position the collar is normal to the piston portion 30a. Spring 11 is secured at its top end to a peripheral flange 11a of collar 15 by means of link 11b, and is secured to the base at its opposite end. The top end of spring 13 is secured to an opposite peripheral ilange 18a of the collar by a link 19 whose lower end is cone-shaped and ts in the similarly shaped top end of spring 18. The lower end of spring 18 is secured to arm 10 by a similar link 80.

Operation of the device of Figs. 1, 2 and 3 is as follows: To establish initial contact of the pad 32 with the work to belifted, the lever 66 isxlifted, which "draws'fltiidl from the reservoir iito chamber 46. Upon downward movement of' the lever, arm 10, through the medium of the spring 18, will raise the left-hand side of collar 15, causiig the collar to bind on the piston portion 30a arid mechanically lift that piston upwardly, and piston 45 will force the iluid from chamber'46 'into chamber 41 past the valve 6|. AIf vone 'suchl'oscillation of shaft 65 is insulicient to contact the pad 32 with the work, the operation may bel"epeate'd until such contact is established. As piston 30 is tl'i's "rnechanically pulled from "1 cylinder |0 the small'amountof fluid forced from chamberl46- will Abe in's'ilioienthto supplyiaidequatemake-up fluid "ft" chamber=41. Thusiadditionalfmake-up lfluid "'*willibe'drawn*'fromithe reservoir through a passageway 82j andfpast'ballfvalve83fwhich latter valve: seatsf'towaids the-reservoir.

lwilli/Ibef-uxiderstocld that duringv eachupward {Ifnv'e ent of lever'` 66' the'flftharidside ofcollar ""lwillibelpulled downwardly by--`spring18 Aand "'the`rightihrid' side'of; thefcollarwillf be pulled iidvfnwairdiyby y`^sip'riji1g 11. v'Ifhediagonal lbore "through"collar5,1insrestagainst"thecollar bind- -`'ing pn thevv pistonjp'ortin 30a during anyf uneven- "r`iess ,in-suchdwnwardimovement l Afteritne pad y|32= retiene-'contacted withfthe work to be lifted, further oscillation of shaft "165-by" 'lever y66will**ca-ilse filuil tobedra-wn from the reservoirrinto" chamber 46on each suction stroke of piston 45%andeachpressure stroke will Lfo'rceglidfpastjvalve@6| "into chamber v41 and thus pi's'ton""30"will beigradually' elevated hydrauiicaiiyfby' pressure' transmittdtd chamber 41. During tliis latter lifting operation, of oursecolfiar is Twin" continuer@ine-"moved np'ialong `with 'tile"'piston'v portion '"30a arid downward relative thereto on'- e' hl suction` stroke ofI piston 45, but fno' effective i; ing 'forcee-n piston portionsu'ewiu fbexertd in 'this manner. inasmuch as tneiiuid A"pressure increase in' chambern oneach pressure "stroke efzpisltenras wiube ineumcient to' raise "pi'stonadistanbe 'edualto' the' distance of travel 'Tof "tliel leftliand'end ofarm "10,"I so construct fys'pring 'IB thatfinits normal posltion'of rest, it isnot"'fu11y"eempre`ssd; 'sd-that arminrwin be "permitted to e'ompieteits `full upward'mevement `^bya'slight'cornpressionof spring 18 from its normal positienf rest.

"'To' lower the ioa'b'e'ing lifted by' the-jack, I provide a valve-actuating"member`85which has a portion'al threadedly mounted in al bore 86 in the base,A and a rod potion85b'which isadapted tocontact and pushball 55 oifits seat torelease pressure in chamber e46. andftherod 51 is con= taetedoy baiifse to mevebaiitl oir its. seat .to release pressure in chamber 41, thusallowingfthe fluid in' both' chambers to return to 'the reservoir. rAfter fthe -jack is` fully lowered, the valve-'actuat- 'ing member; 8-5 V*is mechanically vrotated in the re- *verse direction 'toi allow ve1ves-=55iandI 6| tofbe refturn'edfto-their seatsffby their respective springs, g`so ithatltlie ijackwis Aready "fore-another v--1ifting *operation a body consisting of a base 90, side wall member 9| and cover 02.

The cylinder i0, reservoir cylinder l2, piston 30, piston portion 30a and jack pad 32 are con- 5 structed and mounted as before described and are therefore given like reference numerals. Likewise, passageways 50, 5|, 52, 60 and 82 and the valve elements controlling those passageways are the same as before described and are given like reference numerals.

l'I-lere a"pisto`n |00 i'ciprocates in chamber 46 and has an oppositely disposed guide stem |0| "reciprocally disposed in a cylindrical portion |02 of the cover, the upper end of guide portion |0| l5 nbeing exposed to atmosphere through a port |04. `Fulcrurndin the enlarged medial portion |03 of Athe-piston member, I provide an operating lever |05 having a handle |06, the lever being fulcrumed 7l`x' 'y-`*a""cross pin |01. The lever extends outwardly g() through an opening |"08 in the front of the body @side fwall, which' open-ing is #protected against ventry-lotdustfetc., by afexible rubber coverfing-1H).

l'Thewrmer b'iilurcated :endl |05a=l of the`V levervfis g5 lpivotal-ly connected to a rod'` |5, the top" end-vof 'fw/nich` rod is "pivotally connected-1 by cross pin'fi I6 to bifurcations Ill-Erprojectingoutwardly from'the xperiphery#of l' the.; collar ffl20. .Collar |202` has a. diagonal bore1|20a,1such as'f'before:,describedp'to :an 1 prevent binding upontsdowriwardmovement. vA leaf spring |26 is secured to rod'l why-screws |21 f and `bears?against ltlieftop'@ surface 'of collar: |20 to f-u-rgel-the!l collar? 1'tbvvlrclsthe'top 'end-'fthe cylin- 'iden' l0.

f i 0 iJInoperation?r to establish initial 'contactofhthe C4Wiessee-e1 ef'ffiidlbeingf forced from fluid chamber 46 initov chamber 41v 'on f each'v'do'wnward 4stroke'bf the 'lever' `Iduring i the operationibf establishing initial con-tactothe-pad'with vthework, l as before described, the uid is trapped in chamberl 1:Silice here ASpririgffGZ istffa "strength-Which"wil1 not yield until there is such resistance to'upwa'rd inovem'et of "the lack gindd-liras "will 'be'J afforded by contact with the load. Thus onv each suc- "cessive *operation*` of f1 the i' lever |05, vwhile l" such J contacti'fisilb'eig-established, rv'the "flc'rumf point ment of the lever, piston |00 will be fuith'erwi'thdrawn from: hi'iib'eri 4Farid-'additional'{uid'will f be' 'drawni internat eharhberrrom' the-reservoir `and trapped until -pad 32 contacts *the floa'd. "Thereafter, upon'"each"'pressure stroke 'of piston |00, suflicient pressure will befgener'ate'd in chamb'erts' tounseat valve' 6 l; againstsp'ring 62,'eausberv41` A-lVIake-'up valvevl3-andpassageway82=wi11allow -liuid to Howl-in chamber. 41 duringlfthe'initial nlmovement ofwpiston` 30 before y"the load is-con eIn f- Fig. 7 f I Ishow ma modiedl .formy off lifting collar flllfwhichfdiiers f-romethosevbefore derscribedfonlyf-.in-v gthatf it is comprised-fot spaced resilient leaves |50a @formed `4integral 'fwlth mpe- 5 tive grabbing action on the piston to lift the latter into initial contact with the work load.

In Fig. 8 I show a modified form of rod |60 for connecting arm |05a (Fig. 5) with collar |20, which rod provides means for rendering the jack inoperative when subjected to an overload. I-Iere the rod consists of a cylindrical upper portion |6I longitudinally slotted at |62. The upper end portion of the rod, not shown, is like that of rod |5, for connection to the collar. The lower portion |65 of the rod forms a plunger reciprocable in the base of portion |6|, having radial pins |66 projecting into and movable along slots |62. A compression spring |61 is interposed between shoulder |65a of portion |65 and shoulder |6|a of portion |6|, being disposed spirally around the rod. The spring |61 is made of a strength which will cause it to yield to a predetermined compressive pressure, which would accord with the maximum load capacity of the jack. Thus, since when hydraulic pressure is being generated by piston |l to create lifting pressure in chamber 41, the fulcrum for lever |06 is on the pivotal connection |68 of rod |60 to arm |05a, spring |61 will yield when downward pressure is applied to lever |06 if the jack is overloaded, with the result that arm |a will swing upwardly instead of providing a fulcrum.

I claim:

l. In a jack, the combination of a body presenting a fluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever fulcrumed on the body and operatively connected to the pumping piston, check valve controlled means providing communication between the reservoir and the pressure-generating chamber, check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted, comprising a link carried by the lever and in continuous operative engagement with the work piston.

2. In a jack, the combination of a body presenting a iluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever fulcrumed on the body and operatively connected to the pumping piston, check valve controlled means providing communication between the reservoir and the pressure-generating chamber, check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted comprising a collar loosely fitting around the work piston, and a link operatively connected to the lever and engaging a peripheral portion of the collar.

3. In a jack, the combination of a body presenting a fluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever iulcrumed on the body and operatively connected to the pumping piston, check valve controlled vmeans providing communication between the reservoir and the pressure-generating chamber,

check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted comprising a collar normally disposed normal to the work piston and having a diagonal bore through which the work piston extends, and a link operatively connected to the lever and engaging a peripheral portion of the collar.

4. In a jack, the combination of a body presenting a fluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever fulcrumed on the body and operatively connected to the pumping piston, check valve controlled means providing communication between the reservoir and the pressure-generating chamber, check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted comprising a collar loosely fitting around the work piston, and a resilient link operatively connected to the lever and engaging a peripheral portion of the collar.

- 5. In a jack, the combination of a body presenting a fluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever fulcrumed on the body and operatively connected to the pumping piston, check valve lcontrolled means providing communication between the reservoir and the pressure-generating chamber, check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted comprising a collar loosely fitting around the work piston and a coil spring secured at one end to the lever and secured at its other end to a peripheral portion of the collar.

6. In a jack, the combination of a body presenting a fluid reservoir, a main pressure chamber and a pressure-generating chamber, a work piston reciprocally mounted in the main pressure chamber, a pumping piston reciprocally mounted in the pressure-generating chamber, a lever fulcrumed on the body and operatively connected to the pumping piston, check valve controlled means providing communication between the reservoir and the pressure-generating chamber, check valve controlled means providing communication between the pressure-generating chamber and the main pressure chamber, and means for mechanically moving the work piston into initial contact with the work to be lifted comprising a collar loosely fitting around the work piston, a link operatively connected at one end to the lever and connected at its other end to a peripheral portion of the collar, and spring means bearing against a diametrically opposite portion of the collar.

'1. In a jack the combination of a body presenting a pressure chamber, a pressure generating cylinder and a fiuid reservoir, a ram reciprocally mounted in the chamber, valve controlled ports interconnecting the pressure chamber, the pressure generating cylinder and the reservoir,

marcare? f aiirpumping .piston "reciprocally mounted :fin the 4Vpressure `generating. cylinder for `hydraulically raising. the ram, a collar loosely engaging the ram, man actuating-rod .connected at onev endk to the l peripheral portion of the. collar, and .an operating 'lever pivotally connected/atlongitudinally spaced points to'. the -pumping, pistonlandito the other *.iendfof the rod whereby -upon movement of'the yleverfin one direction it fulcrums on the1pist0n and axially moves the rod and whereby upon movement of thelever inthe. other direction it ruler-'ums on the rod andaxially'moves the .pumping piston.

'98. In :a jack, the combination of a body, a Mwork-lifting piston reciprocally mounted in the body, a lever fulcrumed on the body, a collar yloosely ttingaround the piston, vand means operatively vconnecting the lever to arperilpheral fportionof the collar,l said collar being comprised -offspaced iiexible laminae disposed. one 'above anothen '9.'In a jack, the combination of a'bodypresentinga pressure chamber and a pressure-gen- -lerating chamber, a Work piston reciprocally mounted in the IWork chambena pumping piston reciprocally mounted in the pressure-generating chamber, a collar loosely tting aroun-d the Work piston,a shaft disposed transversely of and journaled in the body, means `for oscillating said fshaft,a= pair'of oppositely disposed arms secured -onuthe-shaft, one ofvsaid arms being operatively lsecured to the pumping piston,` means resiliently connecting the other arm to the collar including va coil spring secured at .one end to said arm and =secured at `its other end toa peripheral portion of the collar, and spring means bearing against ...another portion of the collar to normally urge it into position normal to the work piston.

=v10.. Ing jack, the combinatonofa body presenting a pressure chamber and a pressure-generating chamber, a Work piston reciprocally .mounted-in the Work chamber, a pumping piston reciprocally mounted in the pressure-.generating chamber, alcollar loosely tting around the Work .piston,. a lever fulcrumed on the pumping piston, a guide bore in the body axiallywith the pumping piston, said pumping piston having an axial portion slidable in said guide bore, and. a rodoperatively connecting one end of the lever to a peripheral portion of the collar.

Vl1. In a jack the combination of a body presentinga pressure chambelza pressuregeneratingcylinder and .a fluid reservoir; a ram reciprocably mounted in the chamber; valve controlled ports interconnectingthe pressure chamber, the l pressure generating cylinder and the reservoir; a pumping piston reciprocable within said pressure generating cylinder to force fluid into said chamber to elevate said ram; mechanical means fork elevating said ram, including a reciprocable collar surrounding said ram and tiltable thereon .into and out of locking engagement-With said ram; and actuating means connected to said collar and to. :said pumping piston and movable to and' fro to elevate said ram at first throughJsaid 'f1.8 :mechanical meansr and subsequently through said pumpinglfpiston, v'said means-including a'; yield-fin itheirconnectionto said collar vfor'limiting the ac- 'tuatingforce thatimay be applied to said-collar by fsaid actuating-means.

412. Inma jack thecombination of -a bodyr presenting-wa Ypressure chamber, alpressure generat- `ing'; cylinder anda fluid reservoir; a ram recipro- :cably mounted -in' the chamber; valve controlled ports interconnecting the pressure chamber, the wpres'sure x generating cylinder and the' reservoir; 'la pumping-,piston reciprocable Within said pres- `sure` generatingcylinder to force fluid into said chamber. to :elevatesaid ram; mechanical means Ifor 'elevatingfsaid ram, including a reciprocable :collar/'surrounding said ram and tiltable thereon into and outxof locking engagement with said ram; actuating means operatively connected to said collarfand to said pumping piston and having afto .andfromotion for step by stepv actuation of said mechanical meansand for reciprocationof said pumpingpiston; and means interpcsing yield L in theoperation of said `mechanical means eiective to limit the `actuating force that may Ibe --applied to said ram through said mechanical `zmeans.

113. In a jack the combination of a. body presenting a pressure chambena pressure generating cylinder and a uid reservoir; a ram reciprocably'mounted in the chamber; valve controlled ports interconnecting the pressure chamber, the pressurelgenerating cylinder and the reservoir;

a pumping pistonV reciprocably mounted in the pressure generating cylinder for hydraulically Vraising the ram; va collar loosely surroundingthe ram; anactuating rod connected at one end to .-the peripheralportion-of the collar; and an 0pon the-piston to elevate -saidram through said rod 4and-said collar and whereby upon the contacting of the Work by` said ramand the consequent imposition of a greater resistant load upon said ram, said means may yield to permit said lever ..to fulcrum upon said rod. for actuation of said f Mpumping piston.

HERBERT E. PAGE.

"REFERENCES CITED The.following?referencesare of record in the fiile: of .this patent:

UN'ITED STATES PATENTS

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