US320318A - weston - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1. T. A. WESTON.

HOISTING MBGHANISM.

(No Model.) 2 Sheets-Sheet 2.

. A. WESTON.

ING MEGHANISM.

No.'320,`318. PatentedJune 16, 1885.

UNTTED STATES PATENT OEEICE THOMAS A. VESTON, OF STAMFORD, CONNECTICUT, ASSIGN OR TO THE YALE & TOVNE MANUFACTURING HOISTING IVIECHANISM.

SPECIFICATION forming part of Letters Patent No. 320,318, dated June 16, 1885.

Application filed September' 1:2, 1884.

To all whom it may concern:

Beit known that I, THOMAS A. WEsToN, of Stamford, in the county of Fairfield and State of Connecticut, have 'invented certain new and useful Improvements in Hoists or Hoisting Mechanism, of which the following is a speciiieation, reference being had to the accompanying drawings, in which- Figure l is a central vertical section of a geared pulley-block or portable suspended lift embodying my improvements. Figs. 2 and 3 are details taken on the lines 2 and 3 of Fig. 1, and Fig. @L represents a simpler form of lift embodying a part of my improvements.

My invention consists of two prominent features: first, a compact arrangement in a hoist, in connection with a driving-shaft and Vacounter-shaft,of plain spur-gearing by which to communicate power, and, second, a frictional self-braking device for sustaining a load and lowering it safely.

I place upon the projecting end of a driving-shaft in a hoist, and upon the parallel projecting end of a counter-shaft, as many pairs of spur wheels and pinions as desired, all engaged with each other and forming together a train of gears. Thus two shafts only suiiice for any numberof wheels and pinions, all of which are brought about two centers or axes, and are susceptible of being placed within a compact case or boX.

Regarding the second feature of my invention, I am aware that there are many self sustaining or automatic brake devices already known, the most common of which has the winding-drum shaft connected by pawls and ratchets with abrake-pulley,the friction-band applied to the latter being kept in tension. By releasing the said tension the brakepulley and drum are allowed to turn with the descending load, as desired. In one wellknown instanceone end of the lifting-chain pulls upon a brake hoop or strap to produce friction upon the brake-pulley, the latter be ing stationary when the load is lifted and rotating when the load is lowered. In my present invention I employ a friction-sleeve (or sleeves) within the chain,drum, or sheave, the said sleeve rotating with the drum in the (No model.)

act of lifting, and being stationary when the 5o load is lowered. My friction-sleeve receives the entire load upon the chain-drum containing it, so that the amount of friction orbrakc resistance is always automatically proportioned to the load. Vhere one sleeve yields insufficient friction, I add a sleeve or sleeves concentrically within and around each other, and each one still receives the full pressure of the load on the drum. The sleeves are alternated with each other so that in lowering a 6o moving one is located between two stationary ones, and vice versa. In the drawings I have shown one sleeve of each kind, or a series of two only, which is sufficient for illustration.

The principle of the repetition of frictional surfaces of disk form is embodied in several of my United States and English patents, and is well known, but by my present invention it is made applicable to concentric cylindrical surfaces, so as in like manner to multiply the 7@ frictional effect thereon of an applied load.

Referring to the letters upon the drawings, in Fig. l A indicates the frame, and B the hollow stay or fixed shaft of the chain-drum C. The latter may be an ordinary chain sheave or drum, but is here shown as a differential sheave, and proportioned so that it has a tendency to run lback of itself under a load. It is provided with a spur-wheel, S, geared to the pinion 7. The latter has its at- 8o tached shaft D (or counter-shaft) extended through the box A', and the sprocket wheel shaft or driving-shaft G likewise passes into and through the said box. Upon the said two shafts D and G, and within the box A, I place the spur-wheels l, 2, 3, Jr, 5, and (5, of which l and (i are fixed to their respective shafts, while the intermediate gears, 2, 3, i, and 5, are loose thereon. The gears 2 and 3 are cast in one piece, or otherwise joined to- 9o gether, as also are gears 4 and 5.

E indicates a friction-sleeve formed with a ratchet-wheel, E, which latter engages with a pawl, E2, on the frame. (See Fig. 2.) Any other known form of checking device or stop mechanism may be used. \Vithin the sleeve E is another friction-sleeve, F, having a flange, F, and is thereby loosely engaged with a driving-stud, F2, fixed on the druln C.' (See Fig. 3.) The said engagement is a loose one, in order to protect the stud F2 from the downward pressure of the load.

The operation of my improvements as illustrated in Figs, I, 2, and 3 is as follows: A load being supposed to be placed upon the lower block of an endless chain (not illustrated) carried by the differential sheave C, or upon the end of an ordinary chain, if the sheave C be an ordinary toothed sheave or drum the said load may be lifted and lowered as follows: To lift, driving-power is applied sufficiently to the shaft G and its attached pinion I, when the intermediate loose gears, 2, 3, 4, and 5, will transmit the force to the wheel G, fixed to the shaft D, and thence through the pinion 7 to the wheel 8 and sheave and load. In this hoisting movement the sheave or drum C, by friction thereon,.rotates and carries along with it the friction-sleeve E, and likewise the .inner sleeve, F, all turning together around the hollow shaft B. Upon ceasing to hoist the sheave or drum C is arrested from turning backward by force of the load by its friction upon the exterior of the now stationary sleeve E, the latter being held by the pawl E2; also, by the friction inside and outside of the sleeve F, which is squeezed by the load between the arrested sleeve E and the hollow shaft B. Backward motion can only take place against the combined friction ofthe said three pairs of cylindrical frictional surfaces, each of which (receives the full pressure of the load from the ysheave C, and hence the load will be self-sustained. To lower the load, this resisting friction must be overcome by driving the shaft G in the opposite direction to that for hoisting.

If more than three pairs of the cylindrical friction-surfaces are required, additional loose concentric sleeves can be placed within those shown by suitably enlarging their diameters. One series of sleeves would be pegged to the sheeve C by anges, as shown in Fig. 3, and the other series in like manner pegged to the ratcheted sleeve E. The two series alternate with each other in the manner shown by sleeves E and F. The diameters and numbers of the sleeves required would have to be adapted to each particular application by ordinary mechanical rules, according to the load to be lifted, the material used in the sleeves, and the other circumstances of the case.

In Fig. 4i I show my improved frictional device applied to a pulley block or hoist without multiplying gearing, and with only one friction-sleeve. In this ligure A indicates the `frame; B, the driving shaft; C, the hoistingsheave or chain-drum; E, the friction-sleeve,`

provided with a ratchet-wheel, E, and pawl E2, similar to those shown in Figs. I and 2. H indicates a disk or plate fixed to the shaft B by a key, H2, or otherwise, and loosely attached to the sheave C by a stud, H. B indicates an ordinary sprocket-wheel keyed to the sha-ft B.

The operation of this simpler device is as follows: The differential sheave Gis shown of proportions to run down of itself under aload. Upon applying driving force in any usual manner to the sprocket wheel B' sufficient to overcome any suspended load, rotary motion will be transmitted direct through the shaft B, plate H, and stud H to the sheave or drum C, and theload will be raised. During this hoisting movement the sleeve E is also rotated, being carried around by friction on its exterior with the sheave C and on its interior with the shaft B. Upon ceasing to hoist the pawl El and ratchet-wheel E arrest the backward motion of the sleeve E.' The sheave C is arrested from backward motion by its friction upon the exterior of the sleeve E,and by the friction of l the shaft B on the inner surface/nf the now stationary sleeve, and also by the friction of the shaft B upon it-s bearings withi' ithe frame A. In the example, Fig. 4, consist ;ngof a hoisting-sheave of relative differe itial diameter shown, the aforesaid frietiona,1 parts of thel be used alone with other brake devices or without them, simply as a compact arrangement of multiplying gears in connection with the driving-shaft and counter-shaft of a hoist.

Having described my invention, what I claim to be new, and desire to secure by Letters Patent of the United States, is-

l. In a hoisting-machine, a driving-shaft and a counter-shaft driven thereby, in combination with and forming the axles or axes of a connected tra-in of spur-gears, substantially as set forth.

2. The combination, with a hoist-frame, A, of the driving-shaft G, the counter-shaft D,the box A', into which the shafts extend, and the gears connccti ng the two shafts and the sheave or drum C, substantially as set forth. 3. In combination with the winding-drum or main lifting-sheave of a hoisting machine, an internally-contained friction-sleeve or a series of sleeves,operating as an automatic brake actuated by the load, substantiallyas set forth.

4. In combination with the winding-drum or main lifting-sheave of a hoisting-machine,

an internally-contained friction or brake sleeve or sleeves and a ratchet and pawl or equivalent, substantially as set forth.

5. In a hoist, the combination of the shafts D and G, the lifting sheave or drum C, the gears connecting the shafts and communicating lifting-power to the sheave, and a brakesleeve between the sheave and the shaft G,and mechanism, substantially such as described, to loosely connect the shaft with the sheave,

,invention by itself. The first part also may` ICO and pawl and ratchet or equivalent checking mechanism connected with the sleeve, all substantially as set forth. k

6. The combi1iatio1i,with the winding-drum l THOS. A. WESTON.

5 or main iiftingsheave of a hoisting-machine,

provided with au internal friction or brake sleeve, of a driving-shaft and attached plate In testimony whereof I have hereunto sub- 1o scribed my name.

Vitu esses:

NATHL. R. HART,

and stud, whereby the said drum or sheave is XVM. T. PAYNE. rotated, substantially as set forth.

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