US739654A - Lifting-jack. - Google Patents

Description

PATENTBD SEPT. 22, 1903.

No. 739,654. Y v

G. B'. DAVISON. LIP'I'ING JACK. APPLmATIoN Hmm 00T. 11, 1902.

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WITNESSES:

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ivo. 739,654.

UNITED STAT-Es" Ilatented September 22,

PATENT' OFFICE.

enoacngnnnnrr DAvIsoN, or UrioA, New Yoan.

, Lvl FTlfNG-JACKL SPECIFICATION forming part of Letters PatentI N o. 739,654, dated September 22, 1.903.

n Application i'lledOctoher 11,1902.k Serial No. 126.854.' (No model.) l

To all whom it may concern:

Be it known that I, GEORGE BENNETT DAVI- sON, of Utica, in the county of Oneida, in the State of New York, have invented new and; useful Improvements in Lifting Jacks, of which the following, taken in connection with' the accompanying drawings, is a full, clear, and exact description.

This invention relates to improvements in lifting-jacks, and refers more particularly to that class in which a hand-lever and gravityp'awls are employed to control the operation of a suitable plunger, hereinafter described.'

I have sought in this invention to produce a light, strong, and durable wagon-jack which may be readily carried in the hand from place to place and which-is free from bolts or rivetsy and capable of'being readily assembled or disassembled with a minimuml amount of labor and time.

To this end the invention consists in the combination, construction,-andlarrangement of the component parts of a lifting-jack, hereinafter fully described, and pointed out in the claims'. K l

Referring to the drawings, Figure l is a top plan of a lifting-jack embodying my invention. Fig. 2 isa side elevation, partly broken away, of the parts seen in Fig. 1. Fig. 3 is a transverse section taken on line 3 of Fig.` 2. Figs; ai, 5, and 6 are perspective views showing, respectively, the lifting and holding pawls and the link employed for transmitting motion from the operating-lever to,`

the lifting-pawl. Y

Similar reference characters indicate corresponding parts in all the views. Y

In carrying out theobjects of my invention I employ a hollow upright standard 1, which is mounted upon suitable' supporting-legs 2, daring outwardly and downwardly from the base of thehollow standardvl and unitedat their lower ends to a substantially flat baseplate 3, adapted to rest upon'the'ground or other convenient support, the hollow standard 1 being supported a considerable Adistance above the base-plate and is provided with a lengthwise gnide-openinge for receiving a reciprocally-movable lifting-plunger 5. The upper and lower ends of the guide-opening 4. are open, and the plunger 5 is movable through said open ends,- the guide-openjing being of sufficient length to afford ample bearing forlthe plunger 5, and thecentral portion of the plunger is preferably reduced in .thickness,soas to form opposite lengthwise bearing faces or ribs 6 at opposite longitudinal edges of the plunger. This plunger is of substantially the same cross-sectional form throughout its entire length, eX-

cept that the upper end is lslightly enlarged 4for forming a head' '7,havinga substantially dat bearing-face 8. Thehead 7 and body of the plunger 5 are formed integral with each other, and the hollow standard l, legs 2, and base 3 are also cast together, the upper end 'of the upright standardl ibeingformed with an upwardly-projecting lug or ear 9, having a slot or ,opening l0, in which is movable a suitable gravity-pawl 11, the lug 9 being located at one side of the plunger, and the lower edge of the slot or opening 10 serves as a fulcrum upon which the gravity-pawl 11 may be tilted for.Y releasing the plunger in a manner hereinafter described.

.The opposite 'outer faces` of the upright standard l'are formed with lugs 12, which Lare cast 'integral with the standard and form pivotal bearings for an operating-lever 13, the lugsv12 being disposed in proximity to the upper end of the standardv 1,' and the le ver, being pivotally mounted upon `said-lugs, lis also arranged in I proximity to the upper end of the standard and is adapted to rock vertically.` This lever 13 preferably consists of 'a metallic head of malleable iron or vsimilar material, having one end bifurcated to receive the upper end of the standard l,

thereby forming oppositely-arranged arms 14,

.having their intermediate portions provided with apertures 15 for receiving the lugs or Ybearings 12, said arms extendingtransversely beyond the upright standardV and are provided with additional apertures 16, in which is journaled a suitable link 17 for operating ia lifting-paul 18.

The oppositeend of the metallic head of the operating-lever 13 terminates in a hollow boss 19 for receiving a handle 20, said handle fitting in the socket of the hollow boss 19 and is readily removable therefrom during transportation in order to economize in space and facilitate the packing of the jacks in large quantities for storage or shipment.

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rear faces of the -lifting-plunger 5.

The holding and lifting pawls 11 and 18 are preferably formed of cheap cast metal, such as malleable iron, and are provided with openings 2l and 22 for receiving the plunger 5. These pawls are located betweenthe upper end of the standard 1 and head 7 of the plunger 5, the holding-pawl 11 being located beneath the lifting-pawl 18 and is provided with a linger-piece 23, cast integral therewith and extending outwardly and upwardly from the lug or ear 9, whereby the operator may readily engage the portion 23 and rock` the rear end of the pawl upwardly upon the fulcrum previously mentioned for releasing the same from engagement with the front and As previously stated, these pawls are formed Lfrom malleable iron or similar metal, and are therefore too soft to stand the wear incidental to the frictional engagement of the opposite ends of their respective openings with the front and rear faces of the lifting-plunger 5. I therefore provide each of the pawls 11 and 18 with a pair of nibs or biting-teeth 24, which consist of hardened pins of different material from the pawls, such as hardened steel, which are inserted through the walls of the openings in. such manner as to form the front and rear engaging faces of the openings in the pawls, which faces bite upon the opposite edges of the lifting-plunger as the lever is operated, the lifting-pawl serving to elevate the plunger at each downward movement of the handle of the lever 13, and the pawl 1l operates to hold the plunger in its adjusted position.

The lifting-pawl18 projects beyond the rear edge of the plunger and is provided with an additional opening 25 and suitable bearings 26 for receiving the upper end of the link 17. This link 17 is formed at its lower end with pintles 26', cast integral therewith and inserted into the openings 16, the upper end of said link being provided with bearings 27, normally seated in the bearings 26, and is also provided with a hook-shaped extremity 28, projecting throughl and above the'opening 25 and adapted to engage the rear wall of said opening to effect the positive operation of the pawl18 and also to prevent its accidental displacement from engagement with the link 17.

The end walls of the openings 21 and 22 in the pawls 1l and 18 are preferably V-shaped, with theinapexes in close proximity to the opposite edges of the lifting-plunger, and the nibs or pins 24 are inserted through the apexes of these end walls, so as to project inwardly slightly beyond these apexes, so as to insure their engagement with the front and rear edges of the lifting-plunger.'

It is apparent from the foregoing description that the pawls 11 and 18 are fulcrumed respectively upon the lug 9, bearings 27 at opposite sides of the lifting-plunger, and that their ends, which engage the lifting-plunger, are free to drop by gravity, and therefore tend to impinge their nibs against the opposite faces of the lifting-plunger, this tendency in the lifting-pawl serving to lift the plunger when the handle 2O is depressed, and the nibs of the pawl 11 also bite upon the opposite edges of the plunger and prevent further downward movement thereof. 1

When it is desired to lower the liftingplunger gradually, the operator simply engages the portion 23 and rocks the inner end of the pawl upwardly, and at the same time, having a firm grip upon the handle 20, permits the plunger to gradually descend.

In assembling the lever upon the studs 12 and pintles 26 the arms 14 are spread a sufficient distance to receive the studs and pintles for the purpose of'alining the same with their respective apertures in the arms 12, whereupon said arms are drawn or forced toward each other, and the parts are thus positively connected or assembled.

The holding-pawl 11 is provided with laterally-projecting lugs 30, depending from its lower face and projecting into the path of the lever 13, so that when it is desired to lower the plunger instantly it is sim-ply necessary to rock the lever until the upper faces of the arms 14 engage the lugs 30 and elevate the pawl, whereupon the lifting-plunger drops to its lower limit.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. A lifting-jack comprising a hollow upright standard,a lifting-plunger guided on the standard, a lever fulcrumed on the upper end of the standard and extending to opposite sides thereof, a holding-pawl fulcrumed on the standard above and at one side of the lever-fulcrum, a link pivotally mounted on the lever at the other side of the fulcrum and rising therefrom, and a lifting-pawl fulcrumed on the upper end of the link above the holding-pawl and engaging the lifting-plunger for the purpose described.

2. In a lifting-jack, the combination of an upright standard having a lengthwise openin'gfa lifting-plunger guided in said opening, a lever mounted on the standard and extending to opposite sides thereof and having a handle at one end, a link pivotally mounted on the other end of the lever and rising therefrom, a lifting-pawl fulcrumed on the upper end of the link above the lever, and the hold- IOC IIO

ing-pawl fulcrumed on the standard above end of the link above the lever, a gravity holding-pawl fulcrumed on the standard and interposed between the upper end of the standard and the lifting-pawl, and provided with a finger-piece, for the purpose set forth;

4. In a lifting-jack, the combination with an upright standard formed of cast metal and .having bearings cast on its opposite faces, a leverhaving a bifu mated extremity, the arms of which are flexible and perforated to receive said bearings, a plunger guided on the Y standard, a link mounted between said arms, a lifting-pawl mounted on the link and provided with-xlibs for engaging opposite faces

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