US116296A - Improvement in lifting-jacks - Google Patents

Description

cago, in the county tml@ ' PATENT @Trice EMERY GARD, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN LIFTING-JACKS.

Specification forming part of Letters Patent No. 116,296, dated June 27, 1871.

To all whom it may conc-em:

Be it known that I, EMERY R. GARD, of Chiof Cook and State of Illinois, have invented an Improved Lifting-Jack; and I do hereby declare that the following is a full and eXact description thereof, reference being had to the accompanying drawing making part of this speciiication- Figure l being a side elevation of the jack arranged for raising` heavy weights; Fig. 2, a side lelevation of the same arranged for lowering weights; Fig. 3, an elevation of the jack arranged as 'in Fig. 2 and taken at right angles to that view; Fig. 4, a side elevation of the body or standard of the jack, provided with an additional base for more fully adjusting the height of the jack to snit weights situated at various heights; Fig. 5, an elevation of the same taken at right angles to the view in Fig. 4.

Like letters designate corresponding parts in all of the figures.

A represents the base and standard of the jack 5 B, the lifting-bar, moving up and down vertically in the standard as a socket therefor 5 and C, the pawl-lever pivoted to the top of the standard. The lifting-bar B has two sets of ratchet-teeth, one on each opposite edge, so vthat each vibration of the pawl-lever acts upon it to lift it.

This jack is -intended to be perfectly adapted to lifting heavy weights slowly and light weights more rapidly; and, iirst, to this effect it has two pairs of lifting-pawls on the pawl-lever, one pair, D D, with its pivots a a at a comparatively great distance from the fulcrum of the lever, so as to move a greater distance with a given eX- tent of the levers motion, and thus reach past two or three ofthe ratchet-teeth at once; and the other pair, E E, having its pivots b Z) comparatively near the fulcrum of the lever, so as to reach only a single ratchet-tooth at each vibration of the lever, and thereby lift slowly but with greater lever-age. Second, the lever@` is made with a single permanent handle, c, to be used alone when lifting comparatively light weights, and at the other end has a handle-socket, in which to place another handle, d, shown by dotted lines in Figs. 1 and 2, for an additional person or persons to work with in lifting very heavy weights; this additional lever being removable, so as not to encumber the jack when not needed to be used. The upper pawls D D, for lifting light weights, are

thrown back upon-the lever, as shown in the drawing', when the lower suspended -pawls E E are in action for raising heavy weights. The suspended pawlstdo not interfere with the action of the upper pawls, even when remaining 1n gear.

An important feature of this invention is a device for lowering weights automatically by the same action ofthe lever and pawls as when raising weights, the construction, arrangement, and operation thereof being substantiallyr as follows: On the two opposite sides of the standard A swung in to different positions. Their upper ends are curved substantially as shown, or otherwise formed so as to eiiect the purpose desired, and their lower ends are weighted, so vas to hold the upper ends steadily in position for the suspended pawls E E, which project laterally over the guides, to slide on without disturbing them when the device is in action. These guides, when not in use, are swung up into the position shown in Fig. l, and are held there by a sliding band, H, (or its equivalent,) on'the stock of the standard A, this band catching into a notch, f, in the edgeof one ofthe guides, as shown. When the guides are to be brought into action, the one having the notch fis lifted a little to disengage the slide H, which dropslor slides on the standard till it reaches and rest-s on stops g g on the standard, as seen in Fig. 2. The guides then swing down by their own gray'ity into the position shown in Fig. 2, being held there in the exact positions required by stops h h thereon striking the sides of the standard. The upper ends of the guides in this position are such as to throw the pawls E E sliding thereon successively out of gear with the teeth of the ratchet-bar B in descendn g, as indicated at the left hand in Fig. 2, but not to prevent the aseen ding pawl from' taking into the next higher ratchet-tooth, as indicated at the right hand in the same figure. The effect is to lower the lifting-bar by the ordinary action of the lever, a great desideratum in lifting-jacks.

In order to give greater range to the lifting height of the jack, an auxiliary base, I, is employed, as shown in Figs. 4 and 5. This is a socket, in which the standard A slides up and down. There .isprperly a hole in the lower end of the standard, through which a pin or bolt, z', is inserted, and there is a set of holes, l l, in opposite areV pivoted two guides, G G, so that they can bed/A sides of the auxiliary base,through different ones oi' which the bolt I is inserted to vary the height of the standards.

lVhat I claim as my invention, and desire to secure by Letters Patent, is

I. The two sets or pairs of pawls D D and E E on the lever C, substantially as and for the purpose herein specied.

2. The lever (l, provided with the two pairs of pawls I) l) and E E, and having a permanent handle, c, at one end, and a socket for a removable handle, d, at the. other end, for the purpose set forth.

3. The guides G G, arranged and operating in combination with the pawls E E, substantially as and for the purpose herein specified.

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