US125882A - Improvement in differential pulley-blocks - Google Patents

Description

ZVSheetS--Shet i- GEORGE F. CLEMONS & MELVILLE CLEMENS.

improvement in Differential Pulley-Blocks.

Patented April 23, i872.

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A y 2SheetsV-Y-Sheet`j2. GEORGE F; CLEMONS 8L M ELVILLE CLEMENS;y

Improvement in Differential Pulley-Blocks. No, 125,882, Patented Apriv|23,1872.

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Iwzzmm GEORGE F. OLEMONS, OF SPRINGFIELD, AND MELVILLE CLEMENS, OF

I BOSTON, MASSACHUSETTS.

IMPROVEMENT I DIFFERENTIAL PULLEVBLOCKSIl Specification forming part of Letters Patent No. 125,882, dated April 23, 1872 antedated April 6, 1872.

Specification describing certain Improvements in Dii'erential Pulley-Blocks, invented jointly by GEORGE F. GLEMoNs and MEL- vLLE GLEMENs, residents, respectively, of Springield, in thev county of Hampden and State of Massachusetts, and of Boston, inthe county of Suii'olk and State of Massachusetts.

Our said invention relates to the adaptation of differential-grooved pulley-blocks in hoisting-machines, and its characteristic features are as follows, viz.: First, combi ning, with differential-.grooved pulleys, pressure-rollers which are adapted to press and clamp the hoisting-rope or chain in the grooves of the pulleys to make the rope or chain bind tightly in the grooves without slipping when a weight is suspended by it. Second, employing, in combination with differential-grooved pulleys and rope-tightening pressure-rollers, supplementary ditierential-grooved pulleys or rollers, placed below and in the vertical planes of the primary pulleys, for the purpose of giving additional security against the slipping` of the rope or chain. Third, combining` the difierential-grooved pulleys andfchain-tightening pressure-rollers with the commonly-used differential-horned pulley-blocks, for the purposes of preventing the rapid wearing of the chain and the pulley-horns, and to obviate the noi-se and jar and the danger resulting from the slipping of the chain on the horns in hoisting heavy weights. Fourth, covering the grooves of the differentialgrooved pulleys with leather or other suitable material for giving them durable and frictional surfaces for the hoisting-rope or chain to run on.

Figure l is a side elevation, showing the hoisting-machine with primary differentialgrooved pulleys combined with rope-tightenin gpressure-rollers and supplementary differential-grooved pulleys. Fig. 2 is an elevation, showing that face of the machine which is at the left hand in Fig. 1, with the hoisting-ropes broken away below the supplementary pulleys. Fig. 3 is a side elevation similar to Fig. l,

showing the primary differential-grooved pulv leys and chain-tightening pressure-rollers, in combination with common differential chainhorned pulleys substituted for the supplementthe primary pulleys, made of wood, and their grooves covered with leather. Fig. 5 is a transverse center section of the primary pulleys, made of cast-iron, and their grooves covered with leather. Figs. 6 and 7 show, by a side elevation and a center section, a mode ot' adaptingthe suspended weight to act to clamp the rope between the differential pulleys and pressure-rollers. Figs. 8 and 9 show in like manner the same, with double-grooved di'erential pulleys and double rollers, adapted to y give adjustable clamping upon the rope between them. Figs. l() and l1 show, by enlarged scale, the device for making the said clamping action adjustable.

The pulley-blocks are supported in a frame, consisting of a yoke-piece, a, with a suspending hook, b, swiveled in it, and parallel sidestraps c c with vcross-bars d d attached to it, and connected by four axle-pins, e, f, g, and h. Upon the axle-pin e revolve' two grooved pulleys,i and j, united together in one pulleyblock, and of different diameters ofthe pitch circle of their grooves as eleven is to twelve. Upon the axle-pin f revolve two supplementary differential-grooved pulleys, 7c and Z, united in one pulley-block, and having their grooves of the same relative diameters as are the grooves ofthe primary pulleys i and j, and placed, re-V spectively, in the same vertical planes. Upon the axle-pins g and h revolve two pressure-rollers, m and a, which are covered with rubber bands. The roller m is placed in the plane of the groove of the pulley 1'., so as to press upon and clamp the rope in its groove, and the roller n is placed so as to press similarly upon and clamp the rope in the groove of the pulley j. o is a grooved tackle-block pulley, carried in a guard-frame,p,which has a tacklinghook, q, swiveled in its bottom. An endless rope, tting the grooves in the pulleys, passes in two folds over the primary pulleys t' and j, and in one fold under the tackle-block pulley o, the same as in common differential pulleyblock hoisting-machines; but in passing it also over the supplementary pulleys 7c and l, as shown, the weight ends of the rope are gathered together, crossed, and lapped upon the primary pulleys. The supplementary pulleys k and Z serve to co-operate with the primary pulleys t and j in supporting a weight suspended on the tackling-hook q, and they also increase the effective operation of the primary 2 leases pulleys by their lapping the rope upon them. The pulleys k and Z may be made separate, to lact as independent rollers, and only to gather and lap the rope upon the primary pulleys; or they may be dispensed with for raising light weights. The rollers m and n serve to press and clamp the rope firmly in the grooves of the pulleys, at the lead-on and lead-oi' points of the loose fold of the rope, so that when a weight is suspended on the tacklinghook q it stretches the rope tightly in the grooves, wedging it between their sides, and it is held thereby from slipping in the grooves. A weight attached to the hook q acts to revolve in opposite directions, both the lower and the upper pulley-blocks k l and 'L' j with rotary forces, differing in the proportion of the relative diameters of their grooves, or as eleven is to twelve. And the greater rotary force being insufficient to overcome the less rotary force, and also the friction of the moving parts of the machine, the weight will hang suspended, free to be raised or lowered by pulling down either upon the part t or the part u of the rope.

. Fig. 3 shows common differential horned pulley-blocks v and w, substituted in the described combination for the pulleys k and l, and a chain, fitting the horns of the pulleys, in substitution for the rope. The pulley t has eleven horns andthe pulley w has twelvehorns, so that they take up and let oif the chain in unison with the corresponding movements of the grooved pulleys. The grooved pulleys relieve and steady the load upon the horned pulleys, preventing the rapid wearing away of the pulley horns and the wear and stretching of the chain, commonly result-ing by holding it from slipping as its links are successively engaged by the horns, thus obviating the rattling and jarring, and danger of breaking of the chain in its common use.

Fig. et is a transverse center section of the pulleys, showing a mode of making them of wood and covering them with leather. The pulleys are iitted upon cast-iron. hubs w w, which have flanges y y fastened together and clamped upon the sides of the pulleys by screw-bolts z z. Upon the peripheries of the pulleys are formed like grooves, which are covered with leather bands a and b', fastened to the pulleys by pegs c c and glue or cement.

Fig. 5 is a transverse center section, showing the pulleys cast in separate pulleys d and e', and fastened together by having the contiguous sides of their hubs and flanges clutchjointed, and bolted together by screw-bolts f f. The pulley rims are made with like grooves, which are covered with leather bands g and 7L', fastened to the rims with copper rivets.

Rubber or other suitably durable and frictional material may be used in the grooves of the pulleys 'i and j or 7c and l, but for light work or in using a ibrous rope it is not required, and they may be made, like common grooved pulleys, of iron or wood, with the sides of the grooves suitably inclined or curved to fit and hold the rope. The rollers mand n may be made and supported like common pressure-rollers, leather-covered, or of wood or metal surfaces, grooved or plain, and supported in adjustable spring-pressure or weighted boxes to clamp the rope in the pulleygrooves. A convenient way to make their pressure adjustable is to make their axle-pins to turn eccentrically in their end bearings, with suitable attachments to revolve and secure them in position, thereby enabling throwing the rollers in and out from the pulleys and adjusting their clamping pressure. Springplates, with or without adjustable pressure attachments, may be used in place ofthe rollers to press and clamp the rope into the pulley-grooves, but with less advantages of operation than the rollers. The weight suspended upon the tackling-hook q may be made to give the required clamping-pressure of the rollers m and n. Such a mode of operating the pressure-rollers is shown in Fig. l by dotted lines, and also in the accompanying model.

In Fig. 1, z" z" and j j are straps or rods connecting the ends of the aXle-piuf, respectively, to the ends of the axle-pins y and h of the rollers. The bearings of the axle-pins g and h in the cross-bars d d are slotted, so that the rollers m and n may be moved in and out from the pulleys; and the end-bearings of the axlepin fare slotted vertically, so that the axlepin may be moved up and down. By these means the vertical force of the weight being hoistedis taken upon the axle-pins g and h, and acts partly to draw the rollers m and n toward each other and to press them against the rope, with clamping forces varying as the weights are increased or decreased.

ln the model one end of each axle-pin of the rollers is stationary, and their other ends operated horizontally, as described, by but two straps attached to opposite ends ot' the axlepin f. This modification may be used, or another modication, which is to make the ends of the rollers axle-pins and the axle-pin f all stationary on one side of the frame, and to slot, as described, their end-bearings in the frame on the other side, and connect the latter-named ends by the straps i and j.

The weights hoisted may be made to clamp the rope or chain, as required, between the pulleys c' and j and rollers placed below them, as is shown in Figs. 6 and 7, on Sheet No. 2 of the drawing.

Upon the axle-pin f are iitted, to revolve independently, two grooved rollers, r and sf, of suitable diameters to clamp equally the ropes in the two grooves of the pulleys c' and j; and the ends of the axle-pin e are feathered on two sides and fitted to slide freely up and down in vertical slots q q in the frame, so that a weight on the hook q will pull down on the pulleys z' and j and clamp the ropes in their grooves and in the grooves of the 'rollers r and s at the lead-on and lead-off points of the loose or hoisting fold of the rope.

To prevent crushing of the rope overmuch,

massa t 3 the han ges of the grooves bot-h of the pulleys and rollers may be adapted to meet and roll upon each other when the rope is sufficiently compressed and clamped in the grooves to hold it from slipping; or, the axle-pin c may be adapted to touch and rest in the bottom of v the slots q g', when the rope is suiiiciently "which the weight-told of the rope may hang,

if desired, instead of being carried over the pulleys z' and j, as shown.

The clamping pressure produced by the weights may be made adjustable, as shown in Figs. S and 9, and by enlarged scale in Figs. l0 and ll, by carrying the iiattened ends ot' the axle-pin e in slotted circular plates o o', which are adapted to revolve on projection of them, x x', in holes in the frame, and which are adjusted and secured to the ame by screwbolts y y', passing through curved slots in the plates. The inclined slotted bearings w w' of the axle-pin c support partly the weight suspended upon the hook q, and by adjusting the pla-tes o c to bring the slots more or less inclined the weight is proportionably thrown upon or taken oil' from the rollers i" and s.

The described mode of causing a rope or chain to be held and to bind tightly in grooved pulleys, by means of rollers or spring-plates, which are adapted to press and clamp it in the pulley-grooves at the lead-on and lead-off points of the loose fold of the rope or chain, is applicable for other grooved pulleys or wheels than those used in pulley-blocks and tackle; and grooved pulleys used for transmitting power with iibrous or wire ropes may be made greatly more efficient and durablev by using the described means of pressing and clamping the ropes into the pulley or wheel grooves at the lead-on and lead-off points of the loose half of the ropes. In this way the ropes are held positively from slipping, which 1` prevents the rapid wearing of the grooves, and the power is transmitted independently of the length orweight of the ropes, and the ropes may be used to transmit power efticiently at short distances.

We claim as our inventionl. The ropeV or chain tightening pressurerollers g and h, and their described moditications, employed substantially as set forth.

2. The differentialgrooved pulleys iandj, combined with the pressure-rollers g and h, substantially as and for the purposes set forth.

3. The supplementary pulleys lc and l, employed substantially as and for the purposes set forth. 4

4. The differential horned pulleys o and w, combined with the di`erentialgrooved pulleys i and j and pressure-rollers g and h, substantially as and for the purposes set forth.

5. The described mode of producing the pressure of the rollers g and h, according to the weight being hoisted, by means of the connecting-straps 'i' and j', operating substantially as described, or by other equivalent pressure-producing connections of the weight to the rollers.

6. The clamping-rollers r and s', employed in combination with the grooved pulleys i' and j, and adapted to operate together, substantially as and for the purposes set forth.

7. Regulating the weight-pressure upon the j rollers i" and s by means of the adjustablyslotted axle-pin bearings o o of the pulleys z' and j, or by other equivalent weight-pressure, regulating connection ofthe weight to the rollers.

GEO. F. GLEMONS. MELVILLE CLEMENS. Witnesses:

RICHARD WELCH, LAURA D. CLEMoNs.

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