US1238723A - Lift-jack. - Google Patents

Description

v I. H. BURKHOLDER.

LIFTJACK. v APPLICATION FILED FEB. 12141916..

Patented Aug. 28, 1917.

2 SHEETS-SHEET I.

inni ses naar Junren.

JOHN' H. BURKHOLDER, OF ASHLAND, OHIO, ASSIGNOB, TO THE ELITE MANUFACTURING- COMPANY, OF ASHLAND, OHIO, A CORPORATION.

LIFT-JACK.

riesame.

Speccaton of Letters Patent.

Patented Ang. 2%, 191'?.

Application led February 12, 1916. Serial No. 77,969.

To all, whom t may concern:

Be it known that I, JOHN HJBURKHOLDER, a citizen of the United States, residing at Ashland, in the county or' Ashland and State of Ohio, have invented certain new and useul'lmprovements in Lift-Jacks, ci' which thefollowing isa speciiication.

This invention relates to improvements in Lift Jacks, of a type employing a plurality of pawlsfor dogs and which inthis instance are under the control of a single releasing member or unit, all substantially as shown and i described and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a vertical sectional elevation of the jack in one oit' the several `forms shown. Fig. 2 is a sectional elevation on line 2-2, Fig.

1. Fig.` 3 is a cross section looking down on line 3 3, Fig. 1. i

Fig. 4, Sheet 2, is a sectional elevation corresponding substantially to Fig. 1, but with the pawls and their actuating parts in la different relation. Fig. 5 is a sectional elevation of a modification of the jack particularly in the location. and operation of the outer pawl, andFig. 6 is a sectional elevation of still another modiiication. Figs. 7 and 8 are details of the respective pawls or dogs. v

The jack as thus shown has a standard S in and upon which the operating parts are mounted, andthe presentsdescription ap` plies first to Figs. l to 4 inclusive. The rack-bar Z) is slidably mounted in the said standard, as usual, and has teeth 2 onrits inner edge. The said teeth are adapted to be engaged by the pawlsa and 5, also re. ferred to as inner and outer pawls, and 1n Figs. 1 to a are shown as pivoted at 3 and 6 respectively on the inner end of the operating handle 71 or the socket therefor and which constitutes a portion of the handle as understood herein. The said pivots 8 and 6l are equidistant from the handle pivot `7 on said standard or the swell or enlargement thereof within which the said pawls are housed, and said pawls are adapted to act in both raising and lowering the rack-bar as will presently be seen.

A single pawl releasing member or device d 1s employed in this jack and located relatively beneath the said pawls and slidably mounted in the well 9 in the base of enlargement 8f The said well is barrelshaped and said-device has a head 10 with a circular guide portion depending in said well and a ilat top portion with `a projection f its inner side and a horizontal portion g at its outer side, and a stem 14 projects from said head lO down ,through the bottom of well 9 and has a cam lever 15 pivoted on the lower end thereof. A spiral spring 16 en-- circles said stem between the head Al0 and thebottom of said well and is adapted nor mally to exert an upward tension and lift or raise said device with power to throw out the pawls. Otherwise the head l0 is i depressed or drawn down by the action ol cam lever 15 bearing against the bottom of well 9 and retiring said device cl from action.

The pawl 'al has a toe or point 18 next behind its pivot adapted to be engaged by the projection 7L'. on head l0, while pawl 5 has a toe 2O adapted to be engaged by the flat top surface of said head, and these en gagements` are dependent upon the position of the operating lever h which has its socket portion pivoted at 7.

overcome only by means of the greater pressure or lift exerted by the device al the said pawls are successively released from engagement with the rack-bar by the handle or lever on which they are pivoted.

Thus, if the rack-bar is to be lowered as shown in these views, the raising of the handle lowers and releases pawl 4 and it is thrown out and back as seen in Fig. 1 by engagement of its point 18 by projection of device (Z under pressure by spring 16, and the pawl 5 comes into engagement at the sametime by its spring 25. Then as the handle is depressed it will first lower the pawl 5 a sufficient distance before it is released to raise pawl t from domination by device d and to bring it into engaging relation with the tooth next above the one from which it was last released, and pawl 5 willi be disengaged only when pawl 4 is ready to act. rack-bar will rest on pawl t, and the lower- 'ing of said pawl by raising the han-dle will lower the rack-bar also one tooth to be engaged bypa-wl 5, and so on. The action is positive and unfailing, and since a vehicle is usually raised only far enough to clear a wheel from the floor the operation does not involve either much time or adjustment and a tooth-by-tooth operation sufiices.

Referring now to Fig. Ll, we have the same parts as in the foregoing figures but showing the pawl lifting unit Z as retired and ont of operation through the action of cam 15 and the rack-bar as adaptedto be raised. Hence in this case the said device is not in position to act upon. the pawls and both are in positive engaging relations with the rack-bar, one acting on the down stroke of the handle and the otherI on the up stroke. Both pivots 3 and 6 being relatively near the pivot 7 of the handle the operation in any case is 'comparatively easy and each pawl takes up and hold-s what has been raised by the other one. v Fig. 5 contains a modification in the location of the pawl 5. In this view the said pawl is pivoted in the wall 8 of the standard instead of being on the handle or handle socket 7L, and relatively above the said socket as shown. Hence to operate the same by or through the lift unit or device l I provide the said device with an upmirdly projecting finger or extension 26 which is curved inwardly at the top to come beneath the toe or point 18 on said pawl behind the pivot 6 thereof, so that when pawl 5 is freed from engagement with the rack-bar it will be swung bach out of engaging relationstherewith by the upward movement of the device d after the manner and for the purpose set forth in connection with Figs. 1 and 2.

The modification in Fig. 6 shows the small or inner pawl 5 as pivoted on the extremity of the lever or handle socket and the outer and larger pawl pivoted on the handle pivot- Then as this action is repeated the 7, and in order that said pawl 5 may be 65 thrown out of engaging position upon the `raclebar the lower extremity or point of said pawl behind its pivot is curved or bent inwardly at 20, more or less as in the other views to bring the said extremity over the head 10 and oil' center with said pivot 7. This arrangement provides forthe raising of the said head, the lift action of spring 16 which has the requisitestrength to always actuate the pawls when free and tov throw pawl 5 back away fromV teeth 2 when said pawl is liberated therefrom through the en-V gaging action of pawl 4. Otherwise the operation is the same as in the above described forms of the invention as to raising" 80 and lowering the rack-bar.

The lift member or unit l arranged and adapted to operate as herein described is especially emphasized as of the essence of the present invention.

lVhat I claim is:

1. A lift'jacl as described having'a standard with an enlargement at one side and a well at the bottom of` said enlargement, a` rack-bar slidabliy mounted within said standard, a .handle and a plurality of pawls pivotally mounted within said enlargementto operate said bar, and a single releasing member for both said pawls and a spring for said member conned within said well? to press the same upward, and springs toi press said pawls into engagement with said 'rack-i bar. i

2. A lift jack as described having a standard and a rack-bar therein, a setv of pivotally supported pawls adapted to engage'said bar, springs for said pawls, an. operating handle with which said pawls are operatively related, a single releasing member for said pawlswslidably `mounted beneath thez 'said well toraise said member, a cam lever on said stem in bearing relation to the bot-1120 tom of said well, a pair of spring pressed pivoted pawls adapted to engage said bar and having projecting portions opposite said member and adapted to be engaged thereby.

fi. A lift jac-lr asdeseribed comprising a standardhaving an enlargement with a barrel-shaped well perpendicularly its bottom, a handle and a lift barwith rack .teeth 1,238,723 in said standard,` a pair of pivoted springpressed paWls adapted to engage said bar and having` toe extremities, a single releasing member for the pawls in said Well having a stem siidably projected through the bottom of said Well, upright and lateral proj eotions on said member adapted to engage said toe extremities, a spring to raise said member, and means on said stem adapted to dran7 and hold said member down out of engagement 10 with said pawls.

In testimony whereof I affix my signature in presence of two Witnesses.

J OI-IN H. BURKHOLDER.

Witnesses:

SERA A. MARKLEY, C. C. CHAPMAN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.

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