USRE10651E - Josiah baerbtt - Google Patents

Description

J. BARRETT. Assignor to the DUFF. MANUFACTURING COMPANY, (Limited.)

LIPTING JACK.

Reissued Oct. 13, 1885l INVENTOR,

Mm 27a ATTORNJEz eof said lever being journaled in the brackets,

velevation of my improved jack, showing its -opening or slot, c, extending to nearly twot UNITED STATES PATENT OFFICE.

MANUFACTURING COMPANY,

LI FTING (Limmen) or SAME PLACE. y

SPECIFICATION forming part of Reissued Letters Patent N o. 10.651l da'te'd October 13, 1885. Original No. 203,400, dated Febru nry 1 2, i884. Reissue No. 10,574, dated March 24. 1985. Application for reissue illcll September 21.

To all whom it may concernj:

Beit known that I, J osIAH BARRETT, a citizen of the United States, residing at Allegheny, in the county 'of Allegheny and State of Pennsylvania, have invented or discovered certain new and usefullmprovementsin LiftingJacks, of which improvements thefollowingis a specification.

Inthe accompanying drawings, which make part of this specication, Figure 1 is a side working mechanism. Fig.2isafront elevation.

My invention relates to an improvement in that class of lifting-jacks in which the lifting-bar is raised by theoperation of a lever formed along one side or edge of the liftingbar; and the object of my invention is to provide forja continuous movement of the bar either up or down; and to this end myinvention consists -i-n the construction-and combination of parts, all as more fully hereinafter described and claimed;

The box or standard A is made square or rectangular in cross-sect-ion, with a similarlyshaped passage therethrough, and is rmly supported ou the foot ya'by braces b. In the rear side of the box or standard is formed an thirds of its height from the foot upward, and in its front side is formed-an opening or slot, d, extending downward from near the top for nearly half the length of the standard.

.Within the standard is'placed the lifting'A bar B, having ratchet-teeth formed onits front side, and provided at its lower end,on the side opposite the ratchet-teeth, with the foot C, said foot projecting out through the slot c and moving with the lifting-bar.

On the standard A, near the lower end of the slot d, are formed the brackets D D', forming between them a recess, in which is pivoted the operating handle or lever E, t'he pivot-pinas shown. On each side of the pivotal end of the lever are secured the disks ff, which turn back and forth as the' handle or lever is moved up and down. In suitable holes in the disks No. mms.

fj" are joirnaledthe shafts or spindles l l', formed on the lower ends of the pawls h h. 5o These shafts or spindles are so constructed that one end of each shaft or spindle will project beyond the brackets D D',}as shown in Fig. 2, which are provided with curved slots k, to permit of the niovemcntof the shafts. -The openings in the disks ff', in which the shafts Z l are j ournaled, are located on different sides of a vertical plane passing through the axes of the pivot-pin e of the handle or lever E, and are separated a distance equal to that between two teeth on the lifting-bar. The pawls h and h are constructed and arranged to engage the teeth of t-he lifting-bar .one abovetheathen.and. ,.areheld. in such en gagement by the weightedA levers g and y', se- 65 cured to theV projecting portionsof the shaft-s or spindles l Z outside ot' the brackets D D. As the lever or handle is raised, the outer pawl. h, engages a tooth onthe lifting-bar, thereby causing an upward movement of the 7o lifting-bar, this upward movement of the lifting-bar being equal to about one-half the distance between two teeth. 'As the outer pawl is raised, the inner pawl, h', is correspondingly lowered, such downward movenient being also equal to about one-half the distance between two teeth on the lifting-bar. By reversing the movement of the lever E, the inner pawl and lifting-bar are raised and the outer pawl is lowered, the amount of su'ch 8O upward and downward movements of the parts being the same ,as above stated.

The springs s 3', having two arms, as shown, one arm of each -spring being secured in any suitable manner to the weighted levers g g of the pawls, andthe otherarm of each spring being arranged for engagement with the crankarms m, secured to the shaft n, journaledin the brackets D D', said shaft being provided at one end with a handle, F,wherebythe shaft 9o is turned, so as to bring the crank-arms m in engagement with thesprings s s'. f

When it is desired to lower-the lifting-bar, the handle F is turned until the crank-arms m cause the springs s s to engagethe weighted levers'g g' with considerable tension, the tendeucy of such tension being to overcome the action of the weighted levers, and consequently to disengage the pawls from the liftingbar.

In describing the lowering operation, I willA suppose that the handle or lever E is in the position shown ih Fig. 1, and that the inner pawl, h', is held away from the lifting-bar by the spring s', but that the outer pawl, h, is \in engagement with the lifting-har. `Now,v if 1o the handle E be lowered, the outer pawl and lifting-bar will be lowered, such downward movement eiiecting a considerable compression of the spring s as the weighted lever moves down with the pawl, and theweight on the lifting-bar prevents the pawl h from being forced outward by the action of the spring. During this downward movement of the handie and the outer pawl, the inner pawl is moved up, being held away from the lifting-bar 2o by the sp1-ing s', until near the upper limit of its movement, at which point the spring will have reached the limit ot' its expansion, and will permitv the weighted lever to throw the y pawl into engagement withthe lifting-bar, so that as the handle E completes its downward movement the inner pawl will slightly raise the lifting-bar, thereby freeing the outer pawl from the weight of the lifting-bar and enabling the spring s to throw said pawl away from the 3o lifting-bar. As the handle E is raised the above operation is repeated, the lifting-bar being lowered by the inner pawl, the downward movement of said pawl compressing its spring s', and the outer pawl being held away from the lifting-bar by its spring s until the handle approaches the upper limit of its stroke,

when the outer engages and lifts the lifting bar, so as to free the inner pawl. y In this inanner a continuous uninterrupted lowering 4o movement of thelifting-bar is effected by the up-and-down movement of the lever E,;a simi-- `lar movement effecting an upward movement when the springs are out of engagement Wit the weighted levers. y

u I claim herein asmy in vention- I 1.\I,n a l-ifting-jaek,'a'lifting=bar provided with ratchet-teeth on one side only, in -combiuation with an operating-lever aud tw-o pawls'arranged to engage the lifting-bar on the same side, oueabove the other, vand pivoted to said lever in such relation to its fulcrumpoiut that one of said pawlswill engage l.

the lifting-bar during the upward movement of the .operating-lever, and the other pawl will. engage said liftingbar during the downward,

movement of the operating-lever, substantially as set forth.

2. In a liftingjack, a lifting-bar provided With ratchet-teeth, in combination with an operating-lever, pawls-pivoted to said lever,`

one on each side of its fulcrumpoint, and springs adapted to engage said pawls and hold them alternately from engagement with the lifting-bar whilethey are .being raised by the operating-lever, and to permit the pawls to engage said lifting-bar while they are being lowered, such alternate engagement kand disengagement being eiieeted automatically, substantially as set forth.

3. In alifting-jaek, the lifting-bar provided with ratchet-teeth, in combination with an operating-lever, pawls h h', provided with weighted levers g g', and pivoted toft'he operatinglever, one on'eaoh side of its fulcrunrpoint,

substantially as set forth.

, 4. In a lifting-jack, a lifting-bar provided with ratchet-teeth, in combination with an op-l erating-lever, pawls h h', weighted levers g g', springs s s', crank m, and lever F, substantially asset forth In testimony whereof I have hereunto set my hand.

DARWIN S. WoLeoTfr, R. H. WHITTLEsEY.

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