US542722A - Safety attachment for elevators - Google Patents

Description

(No Model.)

U-L. C. ALGORN. SAFETY ATTAGHMENT PoR ELEVATORS.

Patented Jul 2 Sheets-Sheet 1l.

(No Model.) i 2 Sheets- Sheet 2.

y L. C. ALOORN. SAFETY ATTACHMENT POR ELBVATORS. No. 542,722.

Patented July 16 UNITED STATES f PATENT OFFICE.

LUCIEN C. ALCORN, OFGREENSBURG, KENTUCKY.

i SAFETY ATTACHMENT FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 542,722, dated July 16, 1895.

Application lfiled January 31, 1895. Serial NOI 53618453 (N0 model-3 To all whom it may concern:

Be it known that I, LUoIEN C. ALcoRN, a citizen of the United States, residingat Greensburg, in the county of Green and State of Kentucky, have invented a new and useful Safety Attachment for Elevators, of which the following is a specification.

My invention relates to a stop device for use in connection with elevators, and the objects in view are to provide means whereby, when the hoisting-cable is broken or theupward draft upon such cable caused by the weight of the elevator car is relieved, the car will be automatically locked and held from downward movement.

Further objects and advantages of the invention willappear in the following description, and the novel features thereof will be more particularly pointed out in the claims.

In thedrawings, Figure l is a vertical section of an elevator and the contiguous portion of the well, said elevator being provided with stop devices embodying my invention. Fig. 2 is a similar view showing the stop-pawls in engagement with the rack-bars. Fig. 3 is a horizontal section onthe line 3 3 of Fig. l. Fig. 4 is a perspective view of the upper portion of the elevator-car and the stop device carried thereby.

Similar numerals of reference indicate corresponding parts in all the figures of the draw- 8, having cross-bars 9, and pivotally connected y to the said cross-bars upon opposite sides of their centers are levers 10. The lower ends of these levers are connected to the inner ends of pawls 11, fitted slidably in horizontal guides 12, secured to the upper surface of the roof or top of the car, and bearing at their outer4 ends against the lower extremities of the 1evers are the actuating-springs 13, which are `between the said levers is a ball or spreader 20, and when the weight of the car is upon thehoistingcable this spreader is drawn upward into contact with the under surface of the horizontal plate, which I will, for convenience, term a supporting-plate, and the upper ends of the levers are spread or deiiected and are heldin contact with the outer ends of the radial guide-slots. This disposition of the 4levers causes the pawls to maintain a position out of contact with the teeth of the rack-bars, and therefore the car is free to move vertically. \Vhen, however, the cable breaks or is allowed to run out by reason'of injury to the elevating mechanism, the spreader drops from its position in contact with the supporting-plate, and by allowing the upper. ends of the levers to Vapproach each other causes the outward movement of the pawls, and hence the engagement thereof with the rack-bars, thus checking the downward movement of the car.

The spreader preferably consists of a polished metallic sphere, and as the levers occupy an inclined position when separated or spread at their upper ends it will be seen that upon relieving the strain on the hoisting-cable the inward pressure of the levers, due to their actuating -springs, will force the spreader downward and thus allow the engagement of the pawls with the rack. 4

From the above description it will be seen that the device is simple in construction and may be manufactured at a comparatively small cost, and that the slacking of the hoisting-cable cannot fail to result in the immediate operation of the locking-pawls.

Various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the principle or sacricing any of the advantages of this invention.

Having described my invention, what I claim is l, The combination with rack bars arranged parallel with the path of an elevator car, of spring actuated pawls disposedin operative relation with the rack bars, intermediately pivoted levers connected at one end respectively to the pawls and converging toward their other ends, a supporting plate provided with radiating guide slots for the free ends of the levers, said slots communicating with a central opening, a hoisting cable eX- tending through said opening in the supporting plate and a spreader attached to the end of the cable and arranged between the upper ends ofthe levers, whereby when the hoisting cable is strained said spreader is brought into contact with the supporting plate and separates the contiguous ends of` the levers, substantially as specified.

2. The combination with rack bars arranged parallel w'ith the path of an elevator car, of spring actuated pawls arranged in operative relation with the rack bars, intermediately pivoted levers connected at one end respectively to the pawls and converging toward their'opposite ends, a supporting plate having radiating guide slots for the free ends of the levers, and a polished spherical spreader attached to a hoisting cable and disposed between the convergent upper portions of the lever, substantially as specified.

In testimony that I claim the foregoing as my own I have hereto allixed my signature in the presence of two Witnesses.

LUCIEN. C. ALCORN.

Witnesses:

I-I. D. HUBBARD, E. H. HoBsoN.

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