USRE5204E - Improvement in hoisting devices - Google Patents

Description

2 Sheets--Sheet 1.

A 1. 1. nuYLE.- Hoisting Devicth Reissued Den.24,1372`.

L f f UNITED STATES JOHN JAMES DOYLE,

0E NEW "YORK, N; Y.

|MPRovEMEN'r IN Hols'rme Devices.

Specification forming part of Letters Patent No. 31,077, dated January 8, 1861; reissue No. 5,204, dated December 24, 1872.

To all 'whom it may concer-n:

Be it known that I, JOHN JAMEsDoYLE, of

the city, county, and State of New York, madean invention of a new and lmproved'Hoisting.

Device and I do hereby declare that lthe folmentalities, whereby the desired end is obtained, and which are specified at the close of .this schedule.

'lo enable those skilled in the art to fully understand and construct apparatus embodying my invention, I have represented in the accom- -panyin g drawing, and will p roce'ed to describe,

a set ofditl'erential-pulley blocks embodying it. Figure 1 cfs-aid drawing is a side view of the said set of dierential-pulley blocks, the sides ofthe shells of the blocks nearest the eye and' a portion of one side of the chain being re: moved. Fig. 2 is an edge view of the same, the shells of the blocks being bisected centrally. Fig. 3 is a central section of the upper block ofthe same.

Similar letters of reference indicate .corresponding parts in the several figures.

A represents a block in which two pulleysheaves, a b, are placed and keyed on a common axis, c. The sheaves a b are toothed, but they are of diii'erent diameters, and consequently one has more teeth than the other, the difference in the number of teeth correspondf ing to the dili'erence in the diameters of the sheaves, the teeth of both sheaves being, of course, of the same size. lhe said two sheaves of different diameters, made fast to each other, constitute a dierential-pulley sheave; and this sheave and the shell of the block constitute a differential-pulley block. The axis c extends through the shell of the block A, at one side thereof, so that an external sheave, d, may be placed on it. B is an endless chain which passes around the two pulley-sheaves a b in the block A and around atoothed sheave, e, in a single block, C, as shown clearly in Figs.

1 and 2. The axis of the sheave e may have a crank, f, attached to it, as shown in Fig. 2.

To the block A there are attached two guiderollers, the location of which in reference to the dil'erential sheave is fixed, and therefore I call them stationary chainguides-g g, one opposite each of the sheaves a b, and an under lroller, h, is also attached to the lower part of be suspended from any suitable or convenient support F, with the capacity of being turned to any position which may be required.

The operation is as follows: The pulleysheave d of the upper block A or the shfave e of the lower block 'C may be rotated by any convenient power applied either to the rope on the sheave d or to the slack loop of chain between the two pulley-blocks, or to the. crank of the lower block, and at every revolution of the dierential-pulley sheave a. bin a directionfrom left to right, (as indicated bythe arrow 1,)

the lower block C with its weight Dwill `be elevated a space or distance equivalent to half the difference between the eie'ctive circumferences of the two sheaves a b at the positions of the mean lines of the'chain upon them. 1f',

for instance, the larger sheave a has seventeen teeth and the smaller sheave b sixt-een teeth,

the block C will be elevated vertically a space g equal to half the distance between the centers of two teeth at the mean line of the chain on the sheave and it the power be applied to the slack chain depending from the sheave a, it will be multiplied about thirty-four times in being transmitted to' the weight D through the medium of the chain and pulley-sheaves. The power and speed may, of course, be varied by having the diameters of the 'sheaves a b vary more or less in relation wit-l1 each other. The rollers g g serve as guides to prevent the chain from disengaging from the differential sheave,

Y f Y 5,204

and the roller h serves as a guide tov keep they slack portion Brof the chain out of the path ofthe movement of the lower block C. By reversing the movementofthe pulleys the weight D, ofcourse, will descend. n

I do not confine myself to toothed pulleys, for equivalent devices may be used-as, for

`example, pulleys with embedded spaces or sectional stops may be used in order to secure a iirm and suiicient grip or hold of the chain or chain-band in all positions during the ele- Y vation, suspension, or descent of the load.

This invention may be used for lifting loads 'through short spaces, and the slack B' of the chain B may be attached to the barrel or roller of any windlass or hoisting-gin'for the pur-pose of increasin g the power or convenience I :ln the working ofthe same.

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

1. The combination of the differential-pulley sheave, the shell ofthe block, and a. stationary chain-guide for holding the chain to the said sheave, substantially as before set forth.

2. The combination of the differential-pulley sheave, the shell of the block, and two guides arrangedyat opposite sidesofthe differential- -v pulley sheave, snbs'tantiallyas before set forth.

3. The combination ofthe shell of the block and the differential-pulley sheave, a stationary chain-guide, and a swivel for suspending the same, substantially as before set forth.

4. The combination ofthe diierential-pulley Sheave, the shell of the block, and the external sheave,` substantially as before set forth.

5. The combination ofthe dilierential-pulley sheave, the shellof the block, and the under guide for the slack chain, substantially as before set forth.

6. The combination, substantially as before set forth, of the following instrumentalities, viz: the diierential-pulley block with stationary chain-guide, the single block and its swivelhook, the endless chain, and the swivel ofthe dilerentialpulley block, through which swivel the whole apparatus is supported.

In testimony whereof I have hereto set my hand.

` JOHN JAMES DOYLE. Witnesses:

LoUIs SEAMAN, WM. C. HICKS.

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