US1239941A - Lifting-jack. - Google Patents

Description

A. NEAL.

LIFTING JACK.- APPLICATION HLIED MAY 10. 191 z.

Patented Sept. 11,1917.

' S H EET 1 2 SHEETS ALBERT NEAL, or KOKOMO, INDIANA.

LIFTING-JACK.

specification of Letters Patent. Pat-Qntqgd Sgpt, 11, 31917,

Application filed May 10, 1917. Serial No. 167,793.

To all whom it may concern Be it known that I, ALBERT NEAL, a citizen' of the United States, residing at Kokomo, in the county of Howard and State oflndiana, have invented certain new and use ful Improvements in Lifting-Jacks, of which the following is a specification.

The'object of this invention is to provide a lifting jack wherein by the manipulation of a single lever the staff or head may be advanced or retracted at \villwhereby that jack can be used to advantage around tinplate, iron, glass and other hot furnaces, for raising and lowering heavy doors, rolls, and

the like; or underwater at bridges, gas

plants, and pla'ces where the operator cannot get close to the jack and must operate it at long range by means of an extended handle.

A further object is to provide an easy .adjustment for changing the throw of the handle from a short stroke to raise the load to a longer stroke for lowering it.

I accomplish the above and other objects by themechanism illustrated inthe panying drawings, in which Figure 1 is a longitudinal vertical section of my invention set for raising a load, the pawls being'shown in full lines for the raised position of the handle and in dotted lines 1 for the lowered position of the handle. Fig.

2 is a like view showing the handle and pawls in the operation of lowering a load, the parts being shown in full lines forthe lowered position of the handle and in dotted lines for the up-stroke. Fig. 3 is ahorizontalsection on the line 3-3 of Fig. 2. Figs.

4 and 5, are perspective views of the two pawls, detached from all other parts.

Like characters of reference indicate like parts throughout the several views of the drawings.

The staff 6 has notches 7 on one side to be engaged by a pair of pawls 8 and 9, which are pivoted to the hollow head 10 ofa hand lever, on opposite sides of the pivot 11 of the latter. The pawls preferably have a plurality of points to engage a like'plural number of the notches 7, for greater security in the operation of the jack. The pivotal pins of the pawls areseated at the bottoms of suitable grooves in the leverflwhich allow the pawls to be readily removed fromthe lever (see Fig.

The pivot 11 is supported by the walls of a housing 12, which has seats from same a ccom- .justed, and this end terminates with a T- shaped head, the projecting members 16, 16, of which are alternately made to project through suitable openings in the head 10, to contact with stops 17, 17, on one side of the housing-openingand regulate the swing of the lever for raising the load. The stops are farther apart 011 the other side of the leveropen'ing thereby allowing the lever to swing through a larger are before it is stopped by the member 16 when projected on that side. A spring plate 18 can be swung edgewise on its attaching pivot 19 when not wanted for use. The plate has a pin 20 near its free end, which, entering the handle-socket, can be made to lock the handle at either limit of its swinging adjustment on member 16, 16.

On the opposite side of the staff 6 from the notches 7 is a longitudinally extended strengthening rib 21. A slideway conforming in cross section to the cross section of the staff is formed inthe housing 12 to receive the staff, and a suitable base 22, is formed on the bottom of the housing.

The upper pawl 8 has an upward extension from its upper end, on the outer side of which is a vertical lug23 beveled on its side next to the handle, the other side forming an abrupt shoulder, and below it opposite the plurality of points of the pawl is a similarly shaped but obliquely located lug 24:. Still closer to the pivot of the pawl, on the side toward the staff, is a tapering lug 24 which, in certain positions of the two pawls is adapted to contact with a similar lug 25projecting toward it but a little lower down, fro1n the pawl 9. Offset from-the side of the pawl 9 is a vertical arm 25, adapted to sweep across the surface of pawl 8 at eachmoveinent back and forth of the lever. It has a lug 2-6 at its upper end oppositely beveled from lug 23, and adapted to ride over the latter when their sloping faces are brought together, and to lock when their opposite faces arecontacted. Below the lug 26 is an oblique lug 27 which is beveled on its under side, opposite to the bevel on the lug 24, with which lug 24; it is adapted to contact, override and lock at certain posltions of the pawls. The resiliency of the arm 25, which is thin, holds the lugs of the two pawls in a common path with spring enough to pass when their beveled facesare brought into contact. 7

i The operation of my improved jack is as follows: For raising a load the handle 14 is set with itsjhead-member 16 projecting to contact with the two stops 17, 17, and

between these minimum limits of handle movement the pawls E and-9 Wlll alternately engage the notches 7 of the staff and force the staff upwardly;

To lower the load, with the head-member 16 withdrawnfrom contact with the stops 17 which gives the lever a longer or maximum throw.

the hand lever lowered as shown in full lines in Fig. 2, the load on the stafi will be 9 slides out of engagement with the notches of the staff and its lug 27 is moved outside, of lug 24. The handle is thenlowered which lowers pawl 8 and its load, andpawl 9 is held away from staff 6 until its lug 27 has passed above the lug 24:. Further lowering of the handle brings lugs 24 and 25 into contact agaln, which swings the upper end of pawl 8 away from the staff. causing lug 23 on pawl 8 to pass lug 26, thus bringing the pawls back again to the first assumedposltion, except that the staff and load have been lowered.

To keep the staff 6 from dropping out of the standard when the jack is turned upside-down in handling, I prefer to thicken it at 31' tomake a tight enough fit to hold it, and the adiacent walls of the slideway in which it operates may be similarly thickened for the same purpose.

Having thus fully described my invention, what I claim as "newvand wish to secure by Letters Patent of the United States, is

l. Ina lifting-jack, a standard, a notched staff mounted in the standard, a lever piv- Gopies of this patent may be obtained for the handle .la, is set With oted to the standard,'a pair of pawls pivoted to the lever onopposite sides of the lever pivot and alternately engaging the notched staff by the rocking of the lever, means by a greater angular movement of the lever to alternately hold the pawls out of engagement with the next notches above to retract the staff comprising lugs on the from the other pawl having lugs which vari ously engage with the lugs of the first pawl as the two'pawls are moved by a movement of the lever. r

' side of one of'the pawls and an extension i 2. In a lifting-jack, a standard, a notched staff mounted in the standard, lever-pivoted to the standard,apair of pawls'pifvoted tothe lever on opposite sides of the lever pivot and alternately engaging the notched staff by the rocking of the lever, means by a greaterangular movement, of the lever to alternately hold the pawlsout of engagement'with the next notches above.

to retract the staff comprising a pair of lugs on the side ofone' of ,the' pa'wls, said lugs being beveled on one side, -'and an extenslon from the otherpawl'havlng a ;correl sponding pair of oppositely 'bev'eledflugs which variously engage with the 'l'ugs of the first pawl as the two pawls vare moved: by a movement of" ;thelever, ,and'springmeans for insuring engagement between the two sets of lugs.

3. In a lifting-jack, a standard, a notched i stafi' mounted in the standard, a lever pivoted to the standard, a pair of pawls pivoted v to the lever on opposite "sides of' the lever pivot and alternately engaging the'notched.

staff by the rocking of the lever,.me'ans by a greater angular movement of the leverf H to alternately hold the pawls out of engagement with the next notches above. to retract the staff comprising a pair. of lugsion the side of one of'thepawls said lugs being beveled on one side, and an extension from the other pawl having acorresponding pair of opposltely. beveled lugs which variously engage with lugs. of. the first pawl as the" two pawlsare moved by a movement of the lever, spr ng means for, ,insuring enga, e-.

ment of thetwo sets of lugs, another pair of cooperating lugs one lug on each, pawl,;

theangularmoveand means for re ulating mentof the lever.

Inwitness whereof I havehereunto set U my hand and seal at Indianapolis, Indiana, j this 27th day of February. A. D. one thou sand nine hundred and seventeen.

flve cents each, by addressing the Commissioner of Patents} Washington, D. G." j

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