US655705A - Lifting-jack. - Google Patents

Description

No. 655,705. Paten ted Aug. [4, I900.

. G. B. GALLAGHER.

LIFTING JAGIL (Application filed Apr. 23, 1900.)

(N'o'Moda'L) 2 Sheets,Sheet l,

WITNESSES: INVENTOR mm zw 5m.

if 6. 51 M.

No. 655,705. Patented Aug. l4, I900. G. B. GALLAGHER.

LIFTING JACK.

(Application filed Apr. 23, 1900.)

2 Sheets-Sheet 2..

(No Model.)

\NVENTdR.

WITNESSES:

U iTTEn STATES PATENT OF ICE.

GEORGE E. GALLAGHER, OF s'r. MARYS, onio.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 655,705, clated August 14, 1900. Application filed April 23, 1900. Serial No, 13,856- (N'o model.)

T0 at whom it may concern.-

Be it known that I, GEORGE E. GALLA- GHER, a citizen of the United States, residing at St. Marys, in the county of Auglai'ze and State of Ohio, have invented certain new and useful Improvements in Lifting-Jacks; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others Skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to a reversible liftingjack of that class in which the load may be lowered or the strain relieved by a reversal of the step-by-step movement by which the load is lifted or the strain applied.

My invention relates more particularly to a reversing mechanism for a lifting-jack having pawls and a ratchet and its object is to provide a cheap, simple, and efficient mechanism by means of which the ratchet or rackbar may be caused to travel in either direction, as may be desired; I attain these ob-' jects by means of the mechanism and arrangement of parts hereinafter described, and shown and illustrated in the accompanying drawings, in which- Figure 1 is a side elevation of my device, partly in section, showing the lever and its connected mechanism in position to lift Fig. 2, the same, showing the lever at the opposite end of its lifting-stroke and ready to begin another lifting-stroke Fig. 3, the same,'showing my device arranged to lower its load or to release its strain, with the lever in position to begin a lowering-stroke; and Fig; 4, the same, with the lever at the end of said stroke and ready to begin another lowering-stroke.

Like numerals of reference indicatelike parts throughout the drawings.

In the drawings, 1 is a housing frame or casing in which slides a ratchet-bar 2, having along one of its sides ratchet-teeth 3.

4 is a lever pivoted in the housing, as at 5; 6, a pawl pivoted upon the lever, as at 6 on one side of the fulcrum 5; and 7 is another pawl pivoted upon the lever, as at 7, on the other side of the fulcrum;

8 is a flat bar or lever pivotally fulcrumed upon the pivot pin 6 and lying parallel with the pawl 6. In the end of the bar 8 nearest the pawl 6 is a notch or jaw 8, into which projects a pin 6, secured to the side of the pawl 6.

lever, as at 9. This barrel contains a coiled A barrel 9 is pivoted upon the compression-spring 10, which presses outwardly against a plunger 11, the outer point of which rests in an elongated groove in the edge of the plate 8, as at 8 When the bar- -rel is swung on its pivot toward the end of the pawl 6, the spring,through the plunger 11,

swinging of the barrel 9, with its spring and plunger, I provide the barrel with a han dle 1 0.

Rigidly secured to or formed integral with V the pawl 7 is a'backwardly-extending finger. 12, which lies in the same plane with the bar or lever 8. The extremity of the finger 12 opposite the point of the pawl 7 is curved toward the bar 8, as at 12, and the bar 8 is curved in like manner at its extremity toward the finger 12, as at 8, so that these two menibers are adapted to come in contact with each other at a certain portion of each stroke of the lever 4 when the device is set for its lowering or releasing operation. The bar 8 and finger 12 at their opposite ends are also curved toward each other, as shown, and at certain positions of the lever are adapted to contact with each other.

The operation of my device is as follows:

Assuming that the parts are disposed in relation to each other as shown in Fig. 1, the stress of the spring pressed plunger 11 upon the lever 8 will,through jaw 8 and pin 6*,press the pawl 6 against the ratchet. The curved of the ratchet.

movement of the lever i the pawl 6 will lift the ratchet-bar a single step, while the pawl 7 will drop into engagement with the next lower tooth, and thus at each movement of the lever 4 to and fro the ratchet-bar is advanced. The ratchet-bar and its load having been raised to the desired height, the barrel 9, by means of the handle 10*, is swung upon its pivot 9*, so that the spring-pressed plunger is moved into the position shown in Figs. 3 and 4. It will be seen that now the jaw in the end of the lever 8 will press the pawl 6 normally away from the ratchet-bar instead of toward it, as in the former instance. Assuming that the lever 4 is in the position shown in Fig. 3, the ratchet-bar will rest upon the pawl 7. Now if the handle of the lever 4 be lifted the pawl 7 will lower the ratchetbar and the curved end of the lever 8 farthest from its pawl will come in contact with the neighboring curved end of the finger12,which is moving in the arc of a circle of which the pivot 5 is the center. This movement of the finger 12 overcomes the stress of the spring 10, and the lever 8, by means of the jaw 8 and pin 6", throws its pawl into engagement with a tooth of the ratchet-bar, and thus the weight is transferred to the pawl 6. The lever 8 and the finger 12 now yield to the pressure of the spring, and the pawl 7 is thrown away from the rack, (see Fig. 4,) while by the downward movement of the lever 4c the load is permitted to descend a step. As the lever approaches theend of its downward movement the curved portions of the lever 8 and finger 12, which have been in contact, slip by each other and are out of contact, while at their opposite ends the adjoining curved portions of the finger and lever come in contact, and by the wedge-like action of the contacting surfaces pawl 7 is again thrown into contact with the ratchet-bar and again receives the load, permitting the pawl 6 by the pressure of the spring to be thrown out of engagement with the ratchet-bar. lever 41: the two pawls are caused to alternately receive the load and alternately the pawls are caused to clear the ratchet-teeth while the other pawl carries the load down- Thus by the swing of the v the handle or lever 4: instead ofv upon the housing or frame. One of the advantages of this construction is that the lever 4, with its attached parts, may be machined, tooled, finished, and assembled independently of the heavy rough pieces composing the frame or housing and the ratchet-bar.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. In a lifting-jack, a housing or frame, a ratchet-bar longitudinally movable therein, a lever or handle fulcrumed in the housing or frame, two pawls pivoted on said lever at opposite sides of its fulcrum, a spring-controlled lever pivoted upon said first-mentioned lever and adapted to actuate both pawls either toward or away from the ratchet-bar.

2. In a lifting-jack, a ratchet-bar, a lever, two pawls pivoted upon said lover, a lever fulcrumed upon said firstmentioned lever adapted to throw said pawls into or out of operative position, a spring and means for shifting the stress of said spring upon said last-mentioned leverfrom one side of its fulcrum to the other.

3. In a lifting-jack, a housing or frame, a ratchet-bar movable therein, a handle ful crumed in the housing or frame, a pair of pawls pivoted upon said handle and adapted to engage said ratchet-bar, a pivoted lever fulcrumed upon the handle and substantially parallel with one of said pawls and adapted to swing said pawl upon its pivot in either direction, a finger upon the other pawl in the same plane with said lever, a spring mounted upon said handle, means for applying the stress of said spring to said lever at either side of its fulcrum, and projections upon the adjoining faces of said lever and said finger the arrangement of which projections is such that when the spring-pressure is applied to one side of the fulcrum of said lever both pawls will normally engage the ratchet-bar, and when the spring-pressure is applied to the opposite side of the fulcrum of said lever the pawls will alternately be thrown out of engagement with said ratchetbar at each throw to and fro of the handle.

4. In a lifting-jack, a housing or frame, a ratchet-bar movable therein, a handle fulcrumed in the housing, a pair of pawls pivoted upon said handle and adapted to alternately engage the teeth of said ratchet-bar,

IIO

whereby the ratchet-bar is lifted step by step controlled by said 1ever,abarre1 pivoted upon In testimony whereof I affix my signature said handle, a compression-springin said barin presence of two Witnesses. rel, a plunger actuated by said spring and eni gaging said lever, and means for shifting said GEORGE GALLAGHER 5 barrel, spring and plunger, whereby the stress Witnesses:

of the spring maybe shifted to opposite sides D. F. MOONEY,

0f the fulcrum of said lever. WILL 0. SMITH.

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