US155210A - Improvement in pulleys - Google Patents

Description

T. A. wEsT'oN.

Pulleys. l No.15552'l0. j Patentedsept.22,1s74.

UNITED STATES PATENT OFFICEa THOMAS A. WESTON, OF RIDGEWOOD, NEW JERSEY, ASSIGNOR OF ONE- HALF HIS RIGHT TO JOHN HEINS, OF PHILADELPHIA, PA.

IMPROVEMENT IN PULLEYS.

Specification forming part of Letters Patent No. 155,210, dated September 22, 1874; application iiled September 7, 1874.

To all whom it may concem:

Be it known that I, TEoMAs ALDEIDGE WESTON, of Ridgewood, in the county of Bergen and State of New Jersey, have invented an Improved Pulley Brake or Check, of which the following is a specification:

This invention consists of a lover pivoted to the frame or block of the pulley below or eccentric to the axis of the sheave, the outer end of its longer arm being bent horizontally, so as to embrace the periphery of the sheave at the hauling side, and resting in close proximity thereto, or to the rope or chain thereon, and so arranged that When resting in a horizontal or normal position it offers no resistance to the free passage of the rope over the sheave, but when raised slightly from this position the bent arm or' the lever is brought into close contact with the rope and sheave, and their motion thereby arrested.

In the accompanying drawing, Figure l represents in end elevation, Fig. 2 in side elevation, and Fig. 3 in plan (partly in horizontal section) a single-sheaved pulley-block constructed according to my invention.

a is the frame of the pulley-block; b, the sheave, and b2 the axis of the sheave. c is the rope passing over the sheave, and c2 is the hauling or winding side of the said rope. OnA the frame a of the pulley-block, and at a short distance below the axis b2 of the sheave, a lever, d d2, is pivoted at da. The longer arm l ofthe lever extends beyond the winding side of the sheave b, and is bent horizontally, so as to embrace the edge or periphery of the said sheave. The shape of the lever and its position with respect to the sheave bis best seen in Fig. 3. The lever d d2 is capable of turning in a vertical plane on the center d3, so that the longer arm d may be raisedtoward a vertical position, as indicated in dotted lines. When the lever is free to move the weight of its longer arm brings it into a horizontal position, beyond which position the longer arm is prevented from descending by a stop at g, which limits the upward motion of the short arm. The inner face of the longer arm of the lever is concave, or has a groove nearly resembling that in the edge of the sheave, and at the center of the said groove is a roughened or serrated rib, e, which constitutes the griping part of the lever. When the longer arm cl of the lever is in its normal position its griping end, although embracing the edge of the sheave, is not in contact with it or with the rope or cord; but When the longer arm of the lever is raised toward a vertical position, as indicated in dotted lines in Fig. 2, the eccentricity of its axis d3 to the axis b2 of the sheave b brings the griping end of the longer arm d nearer to the periphery of the sheave b, and causes the central griping-rib e of the said grping end to gripe the rope or cord andl arrest its motion. When the rope on the hauling or winding-side o2 is pulled downward, so as to raise any weight or heavy body, no obstruction is oered by the lever d d2 e to its motion, nor is any obstruction offered to the motion of the cord in the opposite direction so long as the cord on the hauling side o2 is vertical; but when the rope on the said hauling side c2 is brought out of a vertical position, so as to make a small angle therewith, as indicated in dotted lines in Fig. 2, it comes in contact with the griping end of the lever, and by now paying out the cord the said griping end of the lever is carried. upward, and its griping action brought into play, and the motion oi' the rope arrested. In this way the descent of the weight or heavy body may be checked at any point; or a cord, f, may be fastened to the short arm cl2 of the lever d d2, by the pulling down of which cord the longer arm d of the said lever may be raised, and its griping-power brought into play; or one of the said levers may be applied to each of the sheaves of a compound pulley-block; or the end of one lever may be extended the whole length of a barrel or drum to operate upon every coil simultaneously of the rope thereon.

In order to effect or assist the return of the lever to its horizontal or normal position, a spring or springs may be employed to press it downward.

When my invention is. to be applied to a pulley having a chain gearing therewith by means 0i' teeth or otherwise, or when the rope, chain, or band is in any way engaged with the sheave, the griping end of the lever vmay be formed to press frietionally only on the rim of the sheave; or it may press upon the rope, as before described.

The apparatus described may be applied to both sides of the same pulley-block, so that either end of the rope or chain may be employed to carry the load.

Having nov;r described the nature of my invention, and the manner in Which the same is to be performed, I Wish it to be understood that I claim as my invention- The combination, with the sheave b and pulley block or .frame a, of the lever d d2, pivoted to the block below, and eeoentrieally of the axis of `the sheave, whereby the rope and sheave are allowed free motion when said lever is at rest, and are griped by it when its long arm is elevated, substantially as and for the purpose set forth.

THOMAS ALDRlDGE WESTON.

Witnesses:

RICHARD SKERRETT, HENRY SKERRETT.

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