US319480A

US319480A - graves

Info

Publication number: US319480A
Authority: US
Publication date: 1885-06-09
Anticipated expiration: 1902-06-09

Description

(No Model.)

L. S. GRAVES.

BLBVATOR SAPETY DEVICE. No. 319,480. Patented June 9, 1885.

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LORENZO' S. GRAVES, OF ROCHESTER, NEW YORK, ASSIGNOR TO` LORENZO S. GRAVES 8L SON, OF SAME PLAGE.

ELEVATOR `SAFETY DEVICE.

SPECIFICATION forming part of Letters Patent No. 319,480, dated June 9, 1885.

Application filed January 30, 1885.

To all whom it may cof/werfe.-

Be it known that I, LORENZO S. GaAvns, of Rochester, New York, have invented an Improved Elevator Safety Device, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to au improved elevator safety device, which is fully described in the following specification, and the novel features thereof specified in the annexed claims.

My improved elevator safety device is represented in the accompanying drawings, in which Figure 1 is a side elevation of the upper portion of an elevator-car embodying my improvement. Fig. 2 is a plan view ofthe same. Fig. 3 represents the sheave-pulley and clamping device. Fig. 4t is a section through the sheave-pulley and clamps on the line xx, Fig. 2. Fig. 5 is a section through the sheave-pulley on the line y y, Fig. 4, showing the manner of attaching the ropes thereto.

In the accompanying` drawings, representing my present invention, A is the elevatorcar, B B,the guideways; OO,the cross-beams, to which the car is attached; D D', the main lifting-cables; E E', the cables connected with the counterbalance-weight; F F, the sheavepulleys, and G G the clamping-screws. The elevator-car may be of any ordinary or preferred construction, and ornamented, if designed for use in the conveyance of passengers. The main lifting-cables D D areconnected with any suitable mechanism for raising and lowering the car, constructed and arranged in any ordinary or preferred manner for this purpose. The counterbalance-cables E E extend upward from the car and pass over suitablepulleys, and thence downward to a counterbalancing weight, H,arranged to travel 'up and down in a suitable well alongside of the elevator, or in any other suitable relation therewith. Both the main lifting-cables D D and the cables E E connected with the counterbalance pass around the pulleys o o o 0,and extend laterally to the sheave-pulleys F F, which are fastened to the screws G G', the arrangement being such that in case the main lifting-cables break or become slack from any 5o cause the counterbalance weight, acting through the cables E E', will cause the sheaves (No model.)

F F and the screws G G to revolve, thereby drawing the ends o o of the cross-beams O O together, as indicated by the dotted lines in Fig. 3, and clamping them firmly against the 5 5 opposite sides of the guideways B B, arresting the descent of the car without jar or jerk, and preventingaccidents from the breaking or slacking of the main lifting-cables. The ends of the counterbalance-cables are wound one 6c or more times about the sheaves F F', and the two sets of cables are attached t0 opposite sides of the sheaves, so that the strain or pull of one set of cables tends to cause the sheaves to revolve in one direction, while the strain of the other set tends to turn the sheaves in the opposite direction. The screws G G', the opposite ends of which are'preferably provided with threads cut in opposite directions, as indicated in Fig. 3, may be threaded directly into 7o the cross-beams, or they may be inserted into the nuts?1 r', fastened to the cross-beams,thelatter arrangement facilitating the setting up of the apparatus. It is obvious, however, that one end only of the screws need be threaded, the other end being provided with a collar outside of one of the cross-beams, to resist the strain caused by clamping the ends of these crossbeams against the guideways. In either case the lead of the screw should be in such a direc- 8o tion that the turning of the sheaves by the strain of the counterbalance-cables attached thereto will draw the ends of the cross-beams together, or move one end of one of the crossbeams toward the corresponding end of the other. The pulleys o oo 0 are mounted so as to revolve independently of each other on suitable bolts or studs inserted in the crossbearns.

As indicated in the drawings, the main lift- 9e ing cables D D pass from. the corner pulleys to the lower sides ofthe sheaves F F, while the counterbalance-cables pass to the upper sides4 of the sheaves, in order that the strain or pull of the two sets of cables may give the sheaves a tendency to revolve in opposite directions, and so that in case the strain of the lifting-cables is released or slackened the counterweightcables may turn the sheaves and screws, thereby clamping the ends ofthe cross-beams against roo the guideways. rlhe ends of the cables are fastened, to the sheaves, as represented in any other preferred manner. lThe clampingbeams may, if desired, beplaced below the car, .the cables being led around suitable pulleys, so as to leavethe interior of the car unobstructed.

In the drawings I have represented the clamps c c as formed by the ends of the crossbeams O C', but it is obvious that the clamps may be independent of the cross beam or beams, if preferred, being hinged or otherwise secured thereto so that their outer ends are capable of being moved to and from the guideways. .The car may be guided by the crossbeams alone, the clamp e @being so conthe guideways, but I prefer to apply to the car the additional guides, (represented as J J, Fig. 1,) which may be made adjustable either in whole or in part to and from the guideways. The lower part of the car is provided with guides arranged in any ordinary or preferred manner.

In order to, secure equality of strain on the counterbalancecables, they may be caused to pass around a pulley attached to the counterbalance; or they may be fastened to the ends of a compensating-lever pivoted at its middle to the weight.

The operation of my improved 'safety device for elevators will have been already understood from the foregoing description. The weight of the car on the main lifting-cables holds the sheaves F F' with one or more turns rstrain on them is released from any cause, the

counterbalan ce-weight, through its cables, will cause the sheaves to revolve, thereby, by .means of the screws G G', drawing the clamps v e together against the guideways, and causing sufficient friction to prevent the descent of the car. The movement of the ear is arrested in a gradual manner and without jerk or strain, such as is produced by the safety devices now generally employed on elevators.

`balance-cables, substantially as described.

2. The combination, with the elevator-car A and guideways B B', of the cross-beams C C', screws G G', and clamps o fv, substantially as described.A

3. The combination, with the elevator-car A, guideways B B', screw-clamps e o, lifting' cable D, counterbalancc-cable E, and suitable corner pulley or pulleys, o, substantially as described.

4. The combination, with the car A, of the cross-beams C C', clamps fu o, screw G, and nut r, substantially as described.

5. rlhe combination, with the car A and guideways B B', of the cross-beams C C', screws G G', sheaves F F', corner pulleys, o o', and the lifting-cables and counterbalance-cables, substantially as described.

6. The herein described safety attachment.'

for elevators, consisting, essentially, of a friction clamp attached to the car and engaging the guideways, in combination with actuating sheaves, and the lifting and counterbalance cables, the latter applied to the actuating-sheaves and wound in opposite directions thereon, substantially as described.

7. In combination, with an elevator-car and its guides, a friction-clam p attached to the car, a screw for actuating said clamps, a sheave or pulley for rotating said screw, and a liftingcable and counterbalancecable applied to said sheave or pulley and acting thereon in opposition to each other to hold the screw stationary, whereby the clamp is held suspended by opposing strains upon thc lifting and counterbalance cables, and is applied by the counterbalance when the strain is relaxed upon the lifting-cable, substantially as described.

LORENZO S. GRAVES.

Witnesses:

GEO. B. SELDEN. L. A. KANE.

ICO