US243013A - Brake for elevators - Google Patents

Description

(No Model.) 4 A C. J. UNDERWOOD.

Brake forElevators. No. 243,013. Patented June 104,1881.

N. PETERS. moumgnpm, Nmingm. DJ;

UNITED STATES.

PATENT OFFICE. i

CHARLES J. UNDERWOOD, OF BOSTON, MASSACHUSETTS.

BRAKE FOR ELEVATO RS.

SPECIFICATION forming part of Letters Patent No. 243,013, dated June 14, 1881.

-pplication filed April 19, 1881. (No model.)

WOOD, of Boston, in the county of Suolk and State of Massachusetts, have invented certain new and usefulrlmprovements in Brakes forl` Elevators, of which the following is a full,`

clear, and exact description.

The purpose of this invention is to provide an attachment to elevators, so that in caseof accident from the breakage of the rope or other cause which would leave the platform or carriage of the elevator free to fall, such fall of the elevator would be automatically arrested, and preferably in a manner to secure the utmost safety in the further downward movement of the elevator by regulating and graduating' the speed thereof. 4

The invention, as to this purpose, consists,in substance,of an arrangement of wei gh ted levers or other equivalent levers having shoes, and severally suspended by cordsfrom the elevator-rope,in combination with a post or posts and an elevator carriage or platform, all substantially as hereinafter described.

In the accompanying plate of drawings,Fig ure lis a view ofan elevator with some parts in vertical section, illustrating the safety attachment of this invention as outof action 5 and-Fig. 2 is a view illustrating the safety attachment as in action. Fig. 3 is a plan view. Fig. 4 is an elevator with the elevator-carriage partly broken out. Fig. 5 is a sectional view of details.

In the drawings, A represents the carriage or platform of an elevator suspended from a hoisting-rope,B, and constructed and arranged to move up and down between suitable stationary guide-posts, C, on opposite sides, and upon guide-anges thereof, all substantially as ordinarily, and therefore needing no more particular description herein.

D E are the opposite sides of lthe elevatorp carriage, which at each of the posts C carries shoe is duplicated at each side of the elevator, and in such duplication the shoes lie directly opposite to each other and have their bearingsurfaces (l located upon opposite sides of the guide-post. Each weighted and shoe lever is suspended from a rope, f, and these several ropes are connected to a common collar, J, which loosely surrounds the elevator-rope B above the carriage A, and this loose collar J is fastened toa fixed collar, K, which is upon the rope A above the loose collar J, by a pin, g, which is rigidly attached to the said loose collar, and is secured to the said fixed collar by a pin, h, that passes through it and rests upon the upper side of the fixed collar, and thus the said loose collar, with its suspended levers F, is carried up and down in the usual upward and downward travel of the carriage. The holdingpin h is adapted by a cord, l, attached to it and to an angular lever, m, connected to a cord, n, to be withdrawn from pin g of the' stationary collar K, when so desired, by the attendant upon the elevator-carriage.

Each'weighted lever F carries a pawl, o, in position to engage with the teeth of a ratchetrail, p, of the elevator, and these pawls and ratchet-rails are severally arranged to allow the levers, as to them, to move downward, but to prevent their upward movement. The suspension-ropes for the levers are of sufficient strength only to support the weight of the levers. A severing of the ropes f, by which the levers F are suspended, or their release in any other wa-y from their support upon the elevator-rope, leaves them free to fall under the action of their weighted ends, and thus the shoes, by their surfaces d, are brought into contact with the guide-posts, and the force of this contact obviously will be in direct proportion to the-weight of the levers and the leverage otherwise exerted by them. As these levers are arranged as herein described, a severing of their suspendin g-ropes occurs, provided the elevator-rope breaks below the position of the loose collar upon the elevator-rope, and thus they are left free to then come into contact by their shoes with the sides of the guideposts; and in case the elevator-rope breaks 4above its fixed collar K, or its tension is there otherwise released, then` the levers are free to drop and come by their shoes into the contact described. Again, this contact of the shoes is- IOO placed. within the control of the attendant upon the elevator through the cords /L Z and lever m, as above described.

From thisdescription it is plain that the levers and their shoes will act, when placed at their bearings upon the guide-posts, according to their leverage and weight, as a stop to the downward travel of the elevator, and thus obviously, under a proper weighting of the same, they are capable of securing the full stop ofthe elevator in such movement, or such an arrest of the same as to allow the elevator to fall and continue slowly and gradually in its downward movement without fully arresting it, and it is preferable to arrange them so as to act substantially in this manner. The fall of the weighted levers is insured because of the pawl o and ratchet p connection between them and the elevator, as has been described, which holds them from jumping up or lifting.

llo steady the movement of the levers F guides are provided, as shown at q.

It is plain that each lever, through its shoe, when in operation, has a thrust against its side of the guide-post, and that the thrust of each is met by a corresponding thrust directly upon the opposite side of the sanne post by another lever and its shoe there arranged. This prevents any twisting or bending of the guideposts when the levers are in operation, and in this respect this invention differs from many ofthe other safety attachments, which, as heretofore constructed and arranged, act against the guide-posts in a direction and in a manner to thrust or throw them out of their true position.

The posts G may be the guide-posts of the elevator or separate and distinct posts therefrom, and as to the levers F, their operation, herein described, may be similarly secured by springs, in lieu of by weights, the springs being suitably applied therefor.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

1. ln an elevator, the combination, with the posts C, the elevator-carriage, and the hoisting rope or cable, of loose levers F, weighted at their outer ends, and provided with brakeshoes H, attached at or near their center directly to the inner ends of said levers, and cords f, attached to the weighted ends of the levers and to the hoisting-rope, substantially as shown. and described, whereby the brakeshoes are adapted to act upon the posts by the direct inward pressure of the lever without the intervention of wedges to force the brakeshoes on the posts, as set forth.

2. The levers F, having brake-shoes H and ropes f, suspendin gthem from the elevator-rope B, and pawl o and ratchet p, in combination with the posts G and an elevator carriage or platform, all substantially as described, for the purpose speciiied.

3. The levers F, having brakeshoes H and ropes f, suspending them from the elevator-rope B through a loose collar, J, and xed collar K, in combination with the posts C and an elevator-carriage, all substantially as described, for the purpose specified.

4. The levers F, having brake-shoes H and ropes f, suspending` them from the elevator-rope through a loose collar, J, and xed collar K, connected together by a pin, g, having a detachable holding-pin, h, in combination with the posts C and an elevator carriage or platform, all substantially as described, for the several purposes specified. f

In testimony whereof 1 have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES J. UNDERWOOD.

Witnesses:

EDWIN W. BROWN, WM. S. BELLows.

Images