US287539A - Lifting-jack - Google Patents

Description

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(No Model.)

J. W. HAWKINS.

LIFTING JACK.

Patented Oct. 30, 1883.

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(N0 Model.) 2 ShetS-Sheet 2 J. W. HAWKINS. LIFTING JACK.

No. 287.539. Patented 001i. 30,1883.

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UNITED ST T S" PATENT OFFICE.

J. WESLEY HAWKINS, OF GALION, OHIO.

LlFTlNG -JACK.

SPECIFICATION forming part of Letters Patent No. 287,539, dated October 30, 1883.

' Application filed September 6, 1883. (No model.)

To all whom it may concern.-

Be it known that I, J. WESLEY HAWKINS, a

v citizen of the United States, residing at the part removed, the rest in vertical section;-

- connections; Fig. 16, vertical central section town of Galion, in the county of Crawford and State of Ohio, have invented a new and useful Improvement in Lifting-Jacks,of which the following is a specification.

My invention relates to that class of liftingjacks in which a ratchet lifting-bar is raised vertically by a lifting-pawl and held in place by a retaining-pawl.

The objects of my invention are, first, to

avoid the possibility of accident from'breaking or stripping the ratchet-teeth; second,

to cause the ratchet-bar, without strain, to be securely gripped by the lifting. and retaining pawls or clutches third, to prevent friction between thelifting-bar and case by applying the power in a direct line with the bar; fourth, to provide devices whereby the machine may.

at any point be instantly converted into a lowering-jack; and, fifth, to provide devices whereby both pawls may be instantly disengaged from the ratchet lifting-bar, permitting the latter to be freely raised and lowered.

I attain these objects by the mechanism illustrated in the accompanying drawings,

wherein Figure 1 represents a side elevation of the complete machine; Fig. 2, a view of case with Figs. 3 and 4, inside and edge elevations, respectively, of removable plate; Figs. 5, 6, 7, side elevation, vertical section, and rear elevation', respectively,-of the lifting -clutch; Figs. 8, 9, 10, vertical section, and side and rearelevations, respectively, of holding-clutch;

Figs. 11 and 12, front and side elevations, re-

. spectively, of ratchet lifting-bar; Fig. 13, side vertical section of part of case containing lifting-bar, lifting and holding clutches, andlifting-lever; Fig. 14, rear elevation of case,with part removed; Fig. 15, rear vertical section of part of case containing lifting and holding clutches, lifting-bar, and raising-lever and ing-bar; andFig. 22, thelsame parts arranged to lower load.

The frame A, preferably of cast-iron, has a part, A, removable, topermit of placing and removing the working parts. Upon the 0p posite lower side is an elongated vertical orifice, Fig. 2, through which projects the toe of the lifting-bar B. Inside the case are cast the lug a, upon which swings the holding-clutch, a seat, a, in which rests one end of the lower bar, 6, of the lifting device, a pin, f, which enters the slot of the tumbler G, and a slot, J, at the back, in which moves the pin of the raising-lever I. In the cap A is a slot, at, through which projects the pin f of the tum=' bler G, and upon the cap is cast a wrist, H, upon which swings the reversing-lever E.

The ratchet-lifting bar B fits and slides freely in the case A, the toe at its lower end,

tical opening at the back of the case, and the upper end projects beyond the top of the case and fits into the head 11, (shown in section in d Fig. 2.)

The lifting and holding clutches O D con sist of metallic frames of rectangular plan, parallel sides, the sides projecting diagonally downward from back to front, and each is provided on its inner side, adjacent to the ratchetteeth, with similar upwardly-projecting teeth, to engage the ratchet-teeth. These clutches surround the ratchet-bar B, the holding-clutcl1 D being suspended on the lug a and the lifting-clutch 0 upon the end of the bard of the lifting device. From one side of each of these clutches projects a lug, d 0, respectively, whose Fig. 11, projecting through the elongated verofiice will be hereinafter explained. This lifting device consists of the lever I, projecting from which is apin that fits in the slot J. On

theupper and lower edges of this bar are semi- V circular bearings offset from each other by about the width of the projecting pin. a A short bar, 1', with rounded ends, rests at one end in the seat a and at the other in the bearing in the lower edge of the bar I, while asimilar bar t", rests at one end in the bearing in the upper edge of the barI, and its other rests in a bearing at the back of and sustains the lift ing-clutch 0. As the outer end of the lever is depressed the bar t" forms a fulcrum by which the bar 13 is raised, and at the same time the two bars 1' t" are thrown into line, thereby securing the combined effects of a lever and knee-j oint, and raising the clutch O in a direct line, which prevents crowding the ratchet-bar against the sides of the case.

The reversing-gear consists of the tumbler G and reversing-lever E. The tumbler is of the form shown in Figs. 18 and 19, the upper end, 71, whereof is a hollow case containing a bolt, h, constantly pressed outward by a spring. This tumbler rests insideof the case, with the pin f entering the slot and the pin f projecting from the tumbler through the slot at in the cap A. the pin H, and its upper end terminates in a yoke, which grasps the pin f, and a springbolt, (see Fig. 16,) which continually presses against the pin. The location of the tumbler is changed by swinging the lower end of the lever E to the right or left, a pin on the lever entering a hole in the case, to hold it in any desired position. By throwing the end of the lever to the left the tumbler is placed in the position indicated by Fig. 20, entirely out of contact with the clutches, thereby permitting them to act naturally with the lifting-bar to raise the load. \Vhen the end of the lever is thrown to the extreme right, the tumbler assumes the position indicated in Fig. 21, when the spring-bolt h presses against the lug d of the clutch D, and the point r presses against. the lug c of the clutch 0, thus disengaging both from the ratchet-bar and permitting it to slide freely.

To lower the load, the lower end of the lever E is thrown to the center, when the tumbler assumes the position shown in Fig. 22, and its operation is as follows: The clutehG, being held outward by the point 9-, does not engage the first teeth of the ratchet, but as it is raised slides past them. The lug c presses on the point 0 and swings the tumbler on the pin f. A curved opening in the upper edge of the slot a" (see Fig. 3) and the spring-bolt 6 permit the pin f to swing upward. At the same time the point r recedes and permits the clutch C to approach the ratchet-bar and engage its next teeth,while the spring-bolt h ispressed against the lug d and forced into its case 71, the clutch D still remaining engaged with the ratchet-teeth by friction. of teeth the ratchet bar is thereby slightly raised, and, the friction being thereby removed, the spring-bolt h forces back the The reversing-lever is pivoted on As the clutch G engages the next series separate pawls, engaging several teeth at the same time, and a cramp, which securely holds without straining the ratchet-bar, the gripbeing increased in proportion to the weight of the load.

I claim as my invention- 1. In a lifting-jack, a lifting device, consisting, essentially, of a lever pivoted to swing vertically on a pin resting in avertical slotin the frame, and two bars, one end of each resting, respectively, in a seat in the frame and a bearing in the lifting-clutch, and theother ends resting on opposite edges of the lever in notches on opposite sides of a cross-line passing through the pivot-pin, substantially as shown, and for the purpose specified.

2. In a ratchet lifting-jack, a lifting and a retaining clutch, each consisting of aframe inclosing the ratchet-bar, having the back and front walls parallel with said bar, the sides diagonal thereto, the lower wall contiguous to the ratchet-bar teeth, and provided on its i11- ner face with two or more corresponding teeth arranged to engage the ratchet teeth, substantially as shown, and for the purpose specified.

3. In a ratchet lifting-jack, a tumbler, such substantially as shown, arranged by means of a lever simultaneously to disengage the lifting and retaining clutches from the ratchet lifting-bar, and simultaneously to permit them to engage it, substantially as shown, and for the purpose specified.

4. I11 a ratchet lifting-jack, in combination with the ratchet lifting-bar, lifting-clutch, and retaining-clutch, a lowering device, such substantially as shown, which, operated by the lifting mechanism, shall disengage the retaining-clutch substantially simultaneously with the engaging of the lifting-clutch, substantially as shown, and for the purpose specified.

5. In combination with the case A, the ratchet-bar B, clutches G D, lever I, and bars i 17, all constructed and arranged substantially as shown, and for the purpose specified.

6. In combi nati on with the bar B and clutches O D, the tumbler G and lever E, all constructed and arranged to operate substantially as shown, and for the purpose specified.

7. The herein described lifting-jack, consisting of the case A, ratchet-bar B, clutches G D, lever I, bars 2' z", tumbler G, and lever E, all constructed and arranged substantially as shown, and for the purpose specified.

In testimony that I claim the foregoing I have hereunto set my hand this 11th day of August, A. D. 1883.

J. IVESLEY HAlVKINS.

\Vitnesses:

C. P. HUMPHREY, DAYTON A. DOYLE.

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