US766789A - Speed-controlled safety-stop for elevators. - Google Patents

Description

UNTTED STATES Patented August 2, 1904.

PATENT OEEICE.

HENRY MASON YOUNG, OF S'l. CHARLES, ILLINOIS, ASSIGNOR TO LYNDEN EVANS, OE CHICAGO, ILLINOIS.

SPEED-CONTROLLED SAFETY-STOF F-OR ELEVATORS.

SPECIFICATION forming part ofLetters Patent No. 766,789, dated August 2, 1904.

Application filed November 27, 1903. Serial No. 182,835. (No model.)

To L7/Z whom it may concern:

Be it known that I, HENRY MASON YOUNG, of St. Charles, in the county of Kane and State of Illinois, have invented a new, useful, and Improved Speed-Controlled Safety-Sto`p for Elevators, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification, in which corresponding characters of reference in the different figures indicate like parts.

My invention relates to passenger elevators, hoists, and lifts; and my object is to so combine an automatic speed-governor and a coacting stop mechanism with one or more of the hoisting-cables thereof that whenever the speed of the car exceeds a predetermined limit a gripping mechanism will be brought into engagement with said cable or cables in such a way as to effectually grip the cable and stop the car.

To this end my invention consists in the combination of the elements hereinafter more particularly described, and definitely pointed pointed out in the claims.

In the drawings, Figure l is a side elevation of a casing, sheave, governor, and stop mechanism embodying' the features of my invention, together with a portion of a cable and the cross-beam of an elevator. Fig. 2 is an end elevation thereof viewed in the direction of the arrow shown in Eig. 1. Fig. 3 is a perspective View of the fitting located upon the sheave-shaft for supporting the governorarm. Fig. 4c is a perspective view of the governor-arm; and Fig. 5 is a plan View of two sheaves with their respective cables and safetystop mechanism, said sheaves being' shown at an angle to each other with means for connecting the stop mechanism of each to cause simultaneous action.

Referring to the drawings, I represents a framework or casing, preferably made from cast metal, which is intended to be mounted upon the usual supporting cross-beams at the top of an elevator-shaft- Within said casing is located a sheave 2, mounted in the usual way upon a shaft 3,'wh1ch is Journaled 1n suitable bearings m the casing l.

The usual hoisting-cable 4 is trained over the sheave 2, one end being attached to the ordinary crossbeams 5, Fig. l, of an elevator-cage, while the other may be connected in any well-known way with a source of power for actuating said cable.

Mounted upon the shaft 3 and secured against rotation thereon by means of a setscrew 6 or in any other approved manner is a fitting (generally designated by 7, Figs. I and 3) having curved arms 8 9 projecting in opposite directions from said shaft. Pivoted at I() upon the arm 9 is a bent arm 1l, which is bifurcated, as shown at I2, Eig. 4, and bored, as shown, for the reception of a pivot-pin. Shoulders'l?, 13 are adapted to engage pins 14. upon the arm 9, thereby limiting the out ward throw of the arm Il, which I style the governor-arm and which is provided with a weight l5 upon its outer end. A spiral spring 16, Eig. l, has one end attached to a lug 17 upon the arm l1, while the other is attached to a screw-threaded rod 18, which is passed through a bore in the end of the arm 8. Nuts tapped thereon, as shown, enable the tension of said spring to be regulated to any desired degree, so as to hold the weight l5 within a certain distance from the shaft as long as the speed of rotation of the latter does not exceed a predetermined rate.

Rigidly attached to a rock-shaft 19, which is journalethas shown, in the lower portion o'l" the frame a, is an arm 20, which projects upwardly beneath and into close proximity to the horizontal portion of the cable 4. A bore `2l in said varm is adapted to receive a pintle 22, projecting downwardly from an oblong head 23, having a corrugated face 24C adapted to bear against the cable l, but normally separated therefrom. The object of so connecting the head 23 with the arm 2O is that any wear by contact with the cable or lack of proper adjustment may be taken up by the insertion of a shim 25, Fig. l, between the end of the arm and said head. The arm 2O is preferably inclined to about the angle shown in Eig. I in order that when swung forward, as hereinafter stated, the head 23 may engage with the cable 4.

An arm 26, having a weight 27 upon its outer end, is rigidly attached to the rock-shaft 19 and tends normally to move the arm 2O forward, so as to bring the head 23 into contact with the cable. A gravity keeper consisting of an arm 28, preferably curved, as shown, is pivoted at 29 to the upper portion of the frame and is provided with a notch or shoulder 30, Fig. 1, upon its under face, which shoulder is in normal engagement with a pin 31 upon the arm 20. When the keeper 28 is lifted, as hereinafter stated, the 2O arm is free to move into an engaging position by the action ofthe weight 27.

The frame 1 is so constructed as to form a housing 32 over the horizontal portion of the cable 4 and in close proximity thereto, as shown, a portion of said housing' above the normal position of the head 28 being preferably inclined, as shown at 38, Fig. l.

The operation of said device is as follows: The tension of the spring 16 is so adjusted as to hold the weight 15 out of contact with the keeper 28 during the normal speed of the elevator-cable; but should said speed accelerate from any cause to an extent to render it dangerous the weight is thrown out of its normal path by reason of centrifugal action, and inasmuch as the weight and keeper lie in the same vertical plane the weight when abnormally moved, as stated, engages with and lifts the keeper 28, thereby releasing the arm 20, which is thrown forward by the weight 27, so that the head 23 is caused to grip the cable 4, thereby causing' it to wedge firmly between the housing 32 and the corrugated face 24 of the head, thus bringing it to a stop. Y It is obvious that the greater the strain upon the cable the more firmly will it be held by the gripping mechanism.

inasmuch as most passenger-elevators employ more than one cable, it is essential that the several sheaves be so placed as to cause the vertical portions of the cables to parallel each other. In order to accomplish this result, the sheaves are usually set at an angle to each other, as shown in Fig. 5, in which the sheaves 2 and 34 are arranged inintersecting planes, while the vertical portions of the cables 4 and 35 are parallel to each other. Only one weighted arm 36 is employed for the two sheaves, it being obvious that both cables should be gripped at the same time by the safety-stop. This is accomplished by attaching the weighted arm 36 to a rock-shaft 37, which corresponds to the rock-shaft 19, and connecting said two rock-shafts to each other by means of a knuckle-joint 38 or other similar well-known connection. The release of the keeper 28 permits the weight 39 to fall, thereby simultaneously actuating both of the shafts 19 and 37 and moving a like stop mechanism upon each into engagement with the cable beneath which it is placed. It is manifest that an indefinite number of sheaves lmay be connected in like manner and all operated in unison by the release of a single keeper, or each sheave may have a separate governor, keeper, and weight-actuated stop mechanism, if preferred.l

It is obvious that a spring may be employed in lieu of the weight 27 and that other forms of releasing or tripping mechanism may be employed without departing from the spirit of my invention.

When the elevator is brought to a stop by the gripping of the cable, it is only necessary in order to release the gripping mechanism and reset it ready to be again automatically tripped in the event of a dangerous acceleration of speed to reverse the action of the cable, so as to partially free it from wedging contact with the head 28 and manually or otherwise cause the weight to be raised and said head to be moved back until the shoulder 3() of the keeper engages with the pin 31, when the cable is free to permit the car to descend.

Having thus described my invention, I claim- 1. A speed-controlled safety-stop for elevators, comprising a centrifugally-acting governor mounted upon the elevator-sheave, a grip in operative proximity to the cable, means for causing said grip to enga-ge said cable, means for normally preventing such engagement and means controlled by said governor for releasing said grip when the speed of the elevator exceeds its normal limit.

2. The combination with an elevator sheave and cable, of a spring-controlled governor having a centrifugally-acting element adapted to eccentrically vary its path of movement with the speed of the sheave, gripping means in operative proximity to but normally out of contact with the elevator-cable, and means for releasing said gripping mechanism by the abnormal action of said centrifugally-acting element.

3. The combination with an elevator sheave and cable, of a centrifugally-acting governor mounted upon the shaft of the elevator-sheave, arrigid stationary housing for said cable in juxtaposition to said sheave, means for wedging said cable against said housing, means for retaining said wedging means in a normal position, means for throwing the same into contact with said cable when released and releasing means controlled by the abnormal action of said. centrifugal governor.

4. A safety device of the class described comprising an elevator cable and sheave, a swinging arm having its free end in operative proximity to the cable, means tending to swing said arm into engagement with said cable, stationary means upon the opposite side of said cable for contacting therewith to oppose the pressure of said arm thereon, akeeper for holding said arm in a normal position, and

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a centrifugal governor mounted upon the shaft of the elevator-sheave, said governor having a spring-controlled eecentrically-movable Weighted element for releasing said keeper when the speed of said shaft is abnormally accelerated.

5. The combination with an elevator sheave and cable, oi' a gravity-actuated arm arranged to swing in the are of a circle and Wedge said cable against a rigid opposing element, of a keeper Afor normally locking said arm out ot' contact with said cable and a centrifugal governor upon said sheave for releasing said keeper.

6. rlfhe combination with a pluralitT of elevator sheaves and. cables, of arms arranged respectively to swing in the arc of a circle to Wedge said cables against rigid opposing elements, means for actuating said arms to engage said cables, means for holding said arms in normal positions, and a centrifugal governor mounted upon one oi. said sheaves for releasing said holding means.

7. The combination with a plurality oi' elcvator sheaves and cables arranged to coact with a single elevator, oil a centrifugal governor controlled by one of said sheaves, normally idle grips or brakes for engaging and locking said cables respectively, means ior connecting said several grips to act in unison, and a keeper controlled by the action of said centrifugal governor, wherebyT an accelerated speed may serve to release said keeper and cause the simultaneous gripping of all oi' the cables.

1n testimony whereof l have signed this specification, in the presence ol two subscribing Witnesses, this Qelth day oi November, 1903.

HENRY MASON YOUNG.

Witnesses:

D. H. FLETCHER, CARRIE E. JoRDAN.

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