US1938404A - Jack - Google Patents

Description

F. L. SHIRE Dec. l5, 1933.

JACK

Filed Oct. 24, 1930 Lug lll

Patented Dec. 5, 1933Y JACK Forrest L. Shire, St. Joseph, Mich., assignor to Y Auto Specialties Manufacturing Company,

San Francisco, Calif.,

fornia,

a corporation of Cali- Application October 24, 1930. Serial No. 490,957 1 claim. (c1. 25e-1oz) My invention relates in general to lifting jacks and has more particular` reference to lifting jacks for vehicles characterized by the capacity for collapsing to small minimum height, whereby the jack may be positioned under a low object to be lifted and then extended to a maximum height, substantially in excess of two times the minimum collapsed height, whereby the jack can be successfully used on modern ballon tire automobiles.

Among the important objects of my present invention is to provide a jack of the double lift type having a novel and simple construction whereby the jack can be made commercially at low cost, wherein the operating parts are at all times protected from external dirt and moisture, and from injury, wherein the 'operating parts comprise extensible telescoping screw members arranged in a novel manner and adapted for projection and retraction solely by the operation of the driving member without the intervention of external forces and wherein the extensible members are operated solely by externally driven means located in the base of the jack assembly to keep low the center of gravity of the assembly and thus to provide an easily positionable, substantially non-tipping vehicle jack. v

These and numerous other objects of my invention will be apparent from the following description, which taken with the accompanying drawing discloses a preferred embodiment of the invention.

Referring to the drawing:

Figure 1 is a vertical cross section taken throughA a jack embodying my invention, the jack being shown in fully collapsed position;

Figure 2 is a vertical cross section taken through the jack of Figure 1, the jack being shown in partially extended position and Vthe section being taken atright angles to that of Figure 1;

Figure 3 is a horizontal cross ysection 'taken substantially along the line 3 3 of Figure 2; andr Figure 4 is a vertical cross section similar to Figure 2, `the jack; being shown in fully extended position.

To illustrate -my invention, I have shown on the drawing, a jack comprising a tubular housing 11 of preferably cylindrical construction upstanding from a base 13 which forms a broad support for the jack.

The upper end of the housing 11 or may be provided with an inwardly'extending annulaiportion 15 defining'a central opening having inwardly extending projections 17 on opposite sides of the opening 15.

The lower end of the housing 11 opens in an enlarged portion 19 providing a recess in which a mounted in a seat 27 formed in the base of the A housing. Y

The gear 21 is preferably of the bevelled type and is driven from outside of the base by means of a cooperating bevelled pinion 29 formed on a stub shaft 31 which' is journalled in a bearing y 33 formed in the walls of the base in position such that the outer end 350i the shaft extends at a convenient angleV to receive the end of a driving crank or other `means ywhereby the driving mechanism may be rotated. The stub shaft hasan axially extending opening 37 adapted to receive the end of a driving member. The pinion is housed in a recess 39 formed in one side of the base at the lower end of the tubular portion l1.

The gear 21 carries an .upstanding internally threaded sleeve 41, preferably formed integrally with the gear and having smooth outer Wall surfaces adapted to engage and be supported by the walls of the tubular portion 11 of the base.

inner sleeve 'lbeing splined to the outer sleeve 49, which in turn is splined to the upper end.

ofthe base. The sleeves 47 and 49 are preferably made of sheet metal and are congurated to provide cylinders having longitudinal inwardlydisplaced portions 51 on oppositev sides of the cylindrical sleeves. The inwardly displaced portions provide longitudinal grooves in the outer walls of the sleeves and corresponding internal beads on lthe inner walls and the configuration is such-that the outer rgrooves ofthe inner sleeve 47 are shaped to slidingly receive the inner beads of the outer sleeve, and the outerV grooves of the outer sleeve 49 are suinciently Wide toreceive the projections 17 at the upper' end of the base 11. In this way the sleeves are slidingly splined together andthe outer sleeve is splined to the'base. The external diameter ofthe outer sleeve 4.9 also is such that the sleeve makes a close sliding fit through the opening at the upper end of the base so Cil Operation If it is desired to extendthe liftingm'ember 47 from collapsed position shown in Figure 1 of the drawing, the driving ,pinion ,29 isirotated conventionally in a clockwise ,direction. The gear 21 is consequently rotated in a clockwise direction viewed from above. 'The inner sleeve k47, being held from rotation by `splined -engagement with vthe upper end of the lbase Vthrough the nesting Asplines 51 of the sleeves and the projection 17 of 'thebase, vwill beprojected because of its double threadedconnec- -tion with thedriving means, vwinch/double connection Acomprises the `threaded connection of A,the nut-55 onthe-'threade'd shank 45, and the threaded connection between the nut 43 formed to-the lower end of -the fshank "45, :whichlatter nut threads `into the `internal threads of the 4'sleeve 41. Whenthe sleeve 41 -is initially-rotated, the frictional resistance between the ythreads of the-nut n43 an'd'of the sleeve "41 will be greater than 'the .frictional resistance between ,the ynut 55 land Ythe Vshank '45. `Consequently, the shank `45 'will turn 1in zthe nut '55 and cause the lifting member lt47'to beprojected -This projection Vwill f continue -until ithe upper -edge of the nut 55locks`fuponla'stop 57`formed inthe yupperend of the rshank'45. `When the `stop S'Ifengages thexup'persideof the nut 55, the shank 45 will be prevented from trotating. The nut 43 `at ethe :lower fend cf -the "shank '45 also lwill be Iheld "from yrotation vso that -continued :rotation Vof `the y'driving Asleeve A41 will elevate'the nut 43 therein and thisin-turn zwill raise the shank 45 rand the ;lifting-member=47 until the fully extended position illustrated in vFigure^4 of thefdrawingdsireached.

Reversal of the driving rotation of course will reverse the foperation `of the elevating screws and will zretract the lifting memberfuntil fully collapsed position is again rreached. :'It should be noted that'the nutf43'rand theshank 45 are threaded in'thesamedirectionfand lvinasmuchy asconformation requires that jacks :be extendedin responseito `a cloek-wisefmotionof the drivinghandle-outsideofthe jack,-the nut' 43 and shank 45 are'illustratedfas havingfright hand threads, in order .to .project the lifting member 47 upwardly when the ,pinion 29 is rotated in a clock-*wise direction inaccordance with prevailing custom.

lIt will rbe noted that when the `jack is in fully-extended Vposition /as'in Figure 4 vof the drawing, all of the threadedoperating parts 'are entirely enclosed-'by imperforate sleeve members including the sleeve"47 formingthe upper lifting member 'andlthe intermediate sleevef49 which sleeve also'issplinedftothe baseito prevent the upper member :from yrotating whereby 'the threaded members -are enabled I tol automatically.zprojectthe upperliftingmember toV a height substantially in excess of ltwice vthe'collapsed height of'fthe jack. ,The construction obviously will exclude foreign-matter -f-rom entering the jack and deteriorating its operating parts. The sleeve-like members also protect the threaded members when the jack is extended or vpartially extended so that if thrown into a tool box and rattled about with other contents of the tool box, the threaded operating screws will not be damaged.

I vdesire also to call attention to the fact that itheupper'liftingfmember comprising the sleeve *47 and lifting head, the intermediate sleeve 49, theiinternally'threaded nut 55 in the bottom of the sleeve 47 andthe member comprising the threaded: portions 43 and 45 are identical to the similarffportions shown in my co-pending application, Serial No. 487,736 filed Oct. 10, 1930 covervingxa jack in which'the driving impulse is delivered at the upper endof the jack standard.

fIn'the vembodiment illustrated'in my co-pending'application, thepart corresponding to the Athreaded portion 43 is threaded directly into the cylindrical'portion ofthe jack base, which is;provided`with1'suitable screw'threads and the part corresponding to the'sleeve 49 of the present application Y is isplined through a rotatable driving nut or collar, which is mounted to theupper end ofthe jack casing approximately in the relativeposition occupied by the splines 17 in the present application, s'othat by rotating the colvla'r,ithe-upper orload-carrying projectable mem'- ber ris rotated with respect `to the base, which results in thesuccessiveprojectionof the loadcarryingY and lifting membersthrough the action of the threaded connection therebetween'and the stopmeans-corresponding to the element 57 of the Vpresent application. I'have thus designed two radically diierent typesof jack, thermajor vportions of Which'are interchangeabla'it being merely necessary to assemble with the lifting mechanism-a Vbase and driving mechanism of desiredtype inlorder'toobtain the -two types `ofua'ck. .'Inthisway I am able to greatly reduce thecost of :producing jacks o'f both types by thus reducing the number of necessary partsrfor both jacks.

xIt'isthought vthat the invention and'numerous ofits-fattendant advantages will'be morefully understood :from `the foregoing description and it is obvious that numerous changes may be made in the form, construction and arrangement of the-several parts `without vdeparting from `the spiritorscope offmyinvention or sacrificing any of its attendant advantages.

Having thus described my invention what I Vclaim as new'and desire to secure by 4Letters Patent is:

In aflifting 'jack having a support frame, the combination of a driving member mounted in thefframeydriving'meansformed at one end of the driving member and extending outwardly thereof, a lifting member having telescopic relation'and threaded connection with the driving member and a second lifting member having telescopic relationship and threaded engagement withv saidiirst lifting member, said driving mem- `ber-andf-saiddifting members being arranged so that when in collapsed position the second lifting member encloses a part at least of the iirst lifting member and both nest within the driving member when-the jack is in-collapsed position and meansrfor preventing rotation of the second z liftingfmember during its longitudinal movement.

FORREST L. SHIRE.

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