US388156A - Lifting-jack - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

A. A. STROM.

LIFTING JACK.

N0. 388,156.v Patented Aug. 21, 1888.

1776519 68 "i m fl o u 0 Qs wom 2 Sheets-Sheet 2.

(No Model.)

A. A. STROM.

LIFTING JACK.

Patented Aug. 21

Zz' wesses:

n. PETERS. Pholuuthognyhor. Waihingtan. 0.1;

UNrTsn STATES ATENT Trice.

AXEL A. STROM, OF AUSTIN, ILLINOIS.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 388,156, dated August 21, 1888.

(No model.)

Z0 all whom it may concern;

Be it known that I, AxELA. Sraoar, acitizen of the United States, residing at Austin, in the county of Cook and State of Illinois, have invented anew and useful Improvement in Lifting-Jacks, of which the following is a specification.

My invention relates particularly to an improvement upon the liftingj ack for which Letters Patentof the United States No. 359,411 were granted me on the 15th day of March, 1887, in which the principal feature of invention is the friction-clutch device for theliftingbar. The clutch referred to involves, briefly stated, two collars on the lifting-bar, one of which is provided with an extension or car, and by forcing the other collar by means of the operating-lever against the car portion of the first-named the collars are forced laterally in opposite directions and.thus grip the bar. The clutch portion of my present improvement involves identically the same principle of construction and operation as that included in my aforesaid former invention, but is simpler than the latter in construction, and easier and cheaper to produce, without being less effective and reliable in its operation.

Besides providing an improved construction of friction-clutch, the object of my present invention is to afford a generally-improved lifting-jack involving a particular construction of the standard for securing the centering of the load upon the jack, whereby the liftingpower shall be exerted vertically through a line central, or nearly so, on the standard and lifting-bar by fuleruining the operating-lever on such line, and the short arm of the lever shall be close to the lifting-bar and accordingly decrease the tendency of the strain exerted through the clutch to bend the bar, which tendency increases with the increase of distance from the lifting-bar at which the power is applied to the clutch, on the principle ,to be more clear,that the shorter the distance laterally from the bar at which the power is applied to the clutch the shorter will be the leverage of the latter, and consequently the less the lateral strain against the bar tending to bend it.

In the drawings, Figure 1 shows a lifting jack involving my improvements in side elevation. Fig. 2 shows the same in sectional elevation, the section being taken lengthwise of the operating-lever, which isshownbroken. Fig. 3 is a partly-sectional face view with the lever and links for connecting it with the lift lug-clutch removed to avoid obstructing parts which it is desired to present clearly; Fig. 4, a section taken on the line 4 of Fig. 1 and viewed in the direction of the arrow, and Fig. 5 a section taken on the line 5 5 of Fig. 4 and viewed in the direction of the arrows.

A is the lifting-jack, having a standard, .13, provided with a base, 0', and expanded laterally and transversely open, as shown at 0, toward its upper end, where it comprises, asa continuation of the lower contracted portion, 0, two parallel sides, q, provided with corresponding U shaped recesses q in their upper extremities, to the bases of which extend the lateral central strengthening-ribs, 1). Toward the base of the transversely-open expanded portion, from the rear of the part 0, the standard is enlarged in a backward direction, as shown at 0 ali'ording a chamber the side walls of which are closer together toward their upper edges than at their bases forward of the part 0 (see Fig. 4-,) for a purpose here inafter described, and a laterally-perforated bearing, a, also serving a purpose hereinafter described, extends upward from the part 0.

Ois the lifting-bar, provided with the usual foot, m,at its lowerend,wl1ich extends through the slot m, commonly provided in the standard in jacks of the present class. The liftingbar is of any ordinary construction, and, though shown to be rectangular in cross-section, may be of any other suitable shape, when of course the parts immediately fitted to it and to which it is fitted, as hereinafter described, should correspond in shape. The bar 0 extends vertically through the standard between the sides q and through a guide-bearing, Z, extending between the said sides.

I) is the operating-lever for the liftingclutch, hereinafterdescribed. It is bifurcated toward its head It to embrace the lifting-bar between the sides of the standard, and from opposite sides of the bifurcated part extend trunnions 1', supported in boxes i, seated in the U-shaped recesses q, in which they are secured, as by cotter-pins 6 passed through opposite sides of the recesses.

E is the lifting-clutch, comprising a collar, h, surrounding the lifting-bar and provided with a lip, 9, extending from a side of the collar and beveled on its inner side in the direction of its extension. Below the collar h, on the side of the lifting-bar at which the lip g extends, is a block, f, corresponding with a portion of the lower collar of the lifting-clutch in my aforesaid former patent, and provided laterally with trunnions t, from which it is connected with and supported by the bifurcated head of the bar D by means of links Z. The block f constitutes a wedge, and is preferably, though not necessarily, beveled on one side, as shown at a Fig. 2, and recessed on its opposite side to embrace, and thus be guided on, the lifting-bar.

From the foregoing description of the construction the operation of the lifting-clutch will be readily understood. Downward pressure on the long arm of the lever D raises the block f, thus wedging it between the beveled lip g of the collar h and adjacent side of the lifting-bar, whereby, owing to the downward and outward flaring form of the block, or upward and inward bevel of the lip, or both, the collar is forced or pressed (at its inner side farthest from the outer side provided with the lip) against the bar in one direction and the block in the opposite direction, or against the direction of pressure of the collar, thus effectually gripping it at different points on opposite sides, the grip inereasing in intensity in proportion to the resistance afforded by the weight to be raised. It will be seen, also, that there is practically no tendency in the clutch to bend or buckle the bar, as the links Z are close to the bar.

To hold the bar in its raised position, I provide a retaining-clutch, E, very similar in construction to the lifting-clutch, and comprising a collar, h, surrounding the bar, and having a beveled lip, 9, like the lip 9, (but, for the sake of convenience, preferably at the opposite side of the lifting-bar,) and a block,f. The blockf, however, with which the lip 57 is normally in engagement, owing to the weight of the collar h, is stationary, or practically so, in the sense that it is vertically confined and held by being confined at converging sides between the contracted sides of the chamber 0 where it is introduced bybeing first inserted into the wider portion thereof and then slid forward. A bifurcated lever, D, embraces the collar h, to which it is attached, near the extremities, as shown at trunnions k, extending centrally from its opposite sides, and near the base of the bifurcated portion it embraces and is fulcrumed. to the bearing n, the long arm extending beyond the standard B into a position where it is conveniently accessible to the operator to be actuated to release the retaining-clutch by downward pressure upon it, which effects the release by raising the collar h and thus freeing it from the wedging effect of the block f. When the retainingclutch is thus released, the lifting-bar may be permitted to fall from its raised position by raising the long arm of the lever D or permitting it to rise until the collar h (in case it shall retain its hold at the lip g on the block f) shall strike a stop, 6, provided to impede its descent in proper position between the sides q of the standard.

The manner of controlling the descent of the lifting-bar isfamiliar to those who are in the habit of using-lifting-jaeks of the general nature of the present device, and need not, therefore, be described herein.

While it is obviously necessary that in the clutch device only either the lip on the collar or the wedge-block shall be beveled, I prefer the construction shown in the respect referred to, though I wish it to be understood that I intend to be included as within my invention also the beveling only of the wedge-block.

What I claim as new, and desire to secure by'Letters Patent, is-

1. In a lifting-jack, the combination, with the lifting-bar and standard, of an operatinglever fulcrumed on the standard, with its short arm extending beyond one side of the lifting-bar, and a friction-clutch comprising a collar on the bar, having a lip projecting from it at the side where the short arm of the lever extends, and a wedge on one side of the lifting-bar in line with the space between the said bar and lip and linked to the short arm of the lever, substantially as described.

2. Ina lifting-jack, the combination, with the lifting-bar and standard, of a lever, D, fulcrumed on the standard, with its short arm extending beyond one side of the lifting-bar, and a friction-clutch, E, comprising a collar, h, on the bar, having a beveled lip, 9, projecting from it at the side Where the short arm of the lever extends, and a block, f, on one side of the lifting-bar in line with the space between the said bar and lip, and linked to the short arm of the lever, substantially as described.

3. In a lifting-jack, the combination, with the lifting-bar, standard, and a lifting-clutch, of a retaining-clutch comprising a collar on the bar having a lip projecting from it on one side, and a wedge-block entirely on one side of the lifting-bar in line with and below the space between the said lip and bar, and confined in its operative position against material vertical play, substantially as described.

4. In a lifting-jack, the combination of a lifting-bar, O, a standard, 13, having a chambcr,o, reduced laterally toward one end, a

lifting-clutch, and a retaining-clutch, E, comprising a collar, 71,, having a lip, g, on one side, a lever, D, engaging with the collar,and a block, f, confined in the chamber 0 on one side of the bar below the said lip, substantially as described.

IIO

5. In a lifting-jack, A, the combination ofa the bar, and a lever, D, fulcrnmed in the restandard, B, having the expanded portion 0, cesses q and linked to the block f, substanbonnded by sides q, having recesses q in their tialiy as described.

upper ends, a1ifting-bar,0, a guide-bearing, AXEL A. STROM. 5 Z, for the bar, a frictionclutch, E, comprising In presence of a collar, h, on the bar, having a. lip, g, on one J. WV. DYRENFORTH,

side and a block, f, below the said lip against CHAS. E. GORTON.

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