US701823A - Lifting-jack. - Google Patents

Description

No. 70I,823. Patented June 3, |902'.

E. WUODINGS.

LIFTING JACK.

n (Application filed. Sept, 4, 1901A (l0 Model.) l 2 Sheets-Sheet I.

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wmllssss :uvam-'ron No. 70|,823. Patented lune 3, |902.

E. WDINGS.

LIFTING JACK.

Aypuction med sepa. 4, 1901. (lo Mndel.) 2 Sheets-Sheet 2.

wrrnlssts wml/dn s f W. @www INVENTUR UNITED STATES PATENT OEEICE.

EMANUEL WOODINGS, OF OAKMONT, PENNSYLVANIA, ASSIGNOR TO VERONA TOOL WORKS, OF OAKMONT, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA.

SPECIFICATION forming partof Letters Patent N 0. 701,823, dated J' une 3, 1902.

Application filed September 4, 1901. Serial No. 74,271. (No model.)

To all whom it may concern,.-

Be it known that I, EMANUEL WOODINGS,

of Oakmont, Allegheny connty,P'ennsylvania,

have invented a new and useful Lifting-Jack,

of which the following isa full, clear, and ex` act description, reference being had tothe ac-r companying drawings, forming part of this specification, in which'-` Figure lis a side Yelevation showingmy improved jack with the partsin position for lifting. Fig. 2 is a horizontal section on linell Il of Fig. 1. Figr3 is aview similarto. Fig.

1, showing the parts in position for lowering.

step by step; and Fig. 4 is a view similar to Fig. 3, showing the position in lowering as the lower pawl takes the. weight and allows the upper pawl to be released.

My invention relates to that class of jacks wherein a toothed bar is moved in either direction step by step by the action of a plurality of pawls and is designed to simplify and improve the mechanism for reversing the movement of the lifting-bar.

In the drawings I show a jack 2 of an ordinary type, having the hollow frame 3, which incloses and guides the toothed lifting-bar 4. The operating-lever 5 is pivoted-to the'flrame at 6, and to its inner end is pivoted the lower pawl 7. The upper depending. pawl 8 -is pivoted to the frame and normally swings inwardly by gravity to engage the teethof the" lifting-bar.

When the parts are in the position shown' in Fig. 1, the two pawls operatein theordi` nary way, the lever being oscillated andthe pawls alternately engaging the teeth.

To reverse the movement of the lifting-bar, I provide a swinging block 9, which is pivoted to the frame at 10 within the casing and is provided with an upper finger 11, which en-A swinging block iscut away in front of the u ponthe upper pawl.

`."bar.A When thetriggeris released, the block assumes theposition shown in Fig. 3, and

when the lever islifted the pinupon the lower pawl riding over thev cam-face of the block isV forced backwardly out of engagement with the teeth, the load then resting On lowering the lever the vlower pawl is moved upwardly into the next tooth above, and as it takes the load the upper pawl is released and the weight upon the block acting by gravity upon the pin of the upper pawl forces it out of engagement with the teeth. As the lever is again raised the toothed bar moves down with the lower pawl until the cam-,surface of the block forces out the lower pawl and at the same time a1- lows the upper pawl to swing into engagement with the next tooth. The lifting-bar is thus lowered step by step. l

The advantages of my invention result from the simplicity of the reversing mechanism. A single weighted lever or block pivoted to the frame acts upon the pawls to reverse the movement when it is released and brought into contact with them.

The device may be cheaply made and is not liable to'get outv of order.

Many changes may be made in the form and arrangement rof the pawls,lthe toothed bar, and the other parts without departing from my invention.

I claim'- 1. A jack having a toothed bar, a plurality of pawls engaging the bar, and a weighted lever pivoted to the frame and arranged to act upon both pawls to reverse their movement; substantially as described.

2. A jack having a toothed bar, a plurality of pawls engaging the bar, a weighted lever pivoted to the frame and having portions arranged to act upon both pawls, and a. latch device arranged to hold the weighted lever in inoperative position; substantially as described.

3. A lifting-jack having a toothed liftingbar, an operating-lever having a pawl engaging the teeth of the bar, a depending pawl pivoted to the frame and also engaging the teeth of the bar, and a weighted lever pivoted at one side to the frame and having a. camsnrface bearing upon lhe lower pawl, and an upper portion arranged to engage the upper pawi, in lowering the bar step by step; substantially as described. 1o

In testimony whereof I have hereunto set my hand.

EMANUEL WOODINGS. Witnesses:

WARREN W. SWARTZ, GEO. B. BLEMING.

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