US744568A - Safety appliance for elevators. - Google Patents

Description

No. 744,568. PATENTED NOV. 17, 1903. 1

W. LASAE.

SAFETY APPLIANCE FOR ELEVATORS.

APPLICATION FILED JUNE 15, 1903.

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iatented fi'ovember 17, 1903.

PATENT OFFICE.

WALTER LASAR, on ST. LOUIS, MISSOURI.

SAFETY APPLIANCE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent N 0. 744,568, dated November 17, 1903. Application filed June 15, 1908. Serial No. 161,409. (No model.) I 1 T0 on whom it may, concern:

Be it known that I, WALTER LASA-R, a citicity of St. Louis and State of Missouri, have invented a new and useful Safety Appliance for Elevators, of which the following is a specification.

My invention relates to elevators, and has for its principal objects to prevent the descent or ascent thereof becoming too rapid and to hold the car in case the hoisting-cable should break.

The invention consists principally in making the track or rail for the safety-clutch or guide-shoe so that it may be crimped laterally when the clutch is applied, but will resume its normal position when theclutch is released.

It also consists in the parts and in the arrangeinents and combination of parts hereinafter described and'claimed.

In the accompanying drawings,which form part of this specification, and wherein like symbols refer to like parts wherever they occur, Figure 1 is a diagrammatic elevation of an elevator system embodying my invention. Fig. 2 is a horizontal section of said system on the line 2 2 of Fig. 1. Fig. 3 is ahorizontal sectionthereof on the line 3 3 of Fig. 1. Fig l is a detail View of the centrifugal clutch, and Fig. 5 is a cross-sectional viewof one form of guidetrack or rail for the locking-clutch, and Fig. 6 is a similar view of a modified form thereof. Fig. 7 is a sectional view ofthe clutch-releasingdevice.

The elevator car or platform 1 is located in an ordinary elevator-shaft and is provided or spaces them. In the construction illustrated in Fig. 5 the base-plate 3 has two parallel ribs 5 extending longitudinally thereof and integral therewith, and said ribs are made sufficiently thin and resilient to crimp or yield to the pressure of the clutches applied transversely thereto, as hereinafter described. zen of the United States, and a resident of the The elevator car or platform 1 has j ournalhangers 6 fixed to the bottom thereof, in which is journaled a shaft 7, which is screwthreaded in opposite directions at its respective ends. threaded nut 8 working thereon. mediate portion of each nut 8 is reduced in diameter and flattened. at opposite sides, ;whereby the end portions of the. nut consti- Each of the threaded ends has a The intertute shoulders. Over the flat portion of the The other end of the the nut said lever prevents the nut Sfrom turning on the shaft 7, sothat the turning of the shaft causesthemovement of the nut lengthwise of the shaft. This endwise move- 7 ment of the nut causes the lever 9 to turn upon its fulcrum, and the turning of the lever causes its outer end to bear transversely against the resilient rib 5 or 5 of the guide track or rail. The pressure of the lever against the resilient rib crimps or deflects 'from its normal vertical plane the portion of the resilient rib close to the end of the'leverw as well as the part directly opposite thereto. In like manner the second rib is deflected by being jammed against the abutment-plate 10 provided therefor. In consequence of the lever 9 and the abutmentpiece 10 (which together constitute a safety-clutch).thus pinching toward each other the portion of the resilient ribs immediately adjacent to them and the adjacent faces of the leverand of the abutment-piece thereby being'closer together than the normal distance between the outer faces of the respective ribs the further descent or ascent of the elevator-car necessitates the continuous bending or crimping of the ribs from the point where theclutch is first set to the point where the elevator stops.

The force thus applied to stop the elevatorcar is not only the friction between the clutches and the guide-tracks or rails, (which is commonly relied upon,) but the resistance of the resilient ribs to the continuous crimping thereof. This last-mentioned force is particularly ady'antageous on account of the fact that in ordinary elevator construction the guide track or rail is usually covered with grease or otherwise lubricated.

The clutch-operating shaft 7 is operated by any suitable mechanism arranged to be set in operation automatically whenever the elevator-car acquires too rapid a speed, whether ascent or descent. For instance, as shown in the drawings, the clutch-operating shaft 7 has a sheave or drum 11, around which passes an endless rope 12. This rope 12 passes from the drum 11 around a pulley 13, mounted on the bottom of the platform 1, and thence over a pulley 1st, journaled at the top of the elevator-shaft, and thence over pulleys 15 16 16 at the bottom of the shaft, and thence to the drum 11. The pulley 14 at the top of the elevator-shaft has pawls 17 pivotally mounted thereon and arranged to cooperate with a stationary housing 18 provided therefor. Said pawls 17 are normally held toward their shaft or spindle by means of springs 1.); but when its speed becomes too great the centrifugal force causes the ends of said pawls to strike against the stationary housing 18, and thereby stop the movement of the pulley 14 at the top of the elevator-shaft. hen the pulley 14: at the top of the elevatorshaft stops turning, the tension on the endless rope 12 increases very greatly. In the normal operation of the parts the force required to drive the clutch-operating shaft 7 is much greater than the force required to drive the several pulleys; but when the uppermost pulley is locked by the pawl 17 the force required to drag the rope around said pulley 14- exceeds the force required to drive the clutchoperating shaft. It results from this arrangement that when the topmost pulley is locked the rope, which normally runs about the several pulleys, but is stationary around the drum 1]., becomes stationary around the pulleys and runs around the drum. Consequently the rope turns the drum 11 and with it the clutch-operating shaft 7, so as to set the clutches against their guide tracks or rails. The clutch-operating shaft is shown threaded, so as to set the clutches upon too rapid descent of the car; but it is obvious that by reversing the direction of the threads on the shaft too rapid ascent of the car may be provided against.

Preferably the elevator-car is provided with a tooth or projecting lug 20 on eachside in position to slide up and down in the space between the longitudinal ribs 5 and 5 of the guidetrack, and thereby not only guide the car, but keep the space free from pieces that might prevent the proper crimping of the ribs. For the latter purpose this space may be closed with wood or other compressible material.

from its engagement.

Obviously the construction hereinbef ore described admits of considerable modification without departing from my invention and I do not wish to be restricted to said construction. Obviously also any suitable device 21 may be mounted on the car forreleasing the clutch For instance, the car may have a hand-lever 22, provided with a pawl 23, arranged to actuate a ratchet-wheel 21L, fixed to the clutch-operating shaft.

The lever22 is enlarged at its lower end and loosely surrounds the clutch-operating shaft. It is hollowed out and receives within it the pawl-ring 25, upon which the pawls are mounted and which surrounds the ratchet-wheel 24, fixed to the clutch-operating shaft. The pawl-ring is provided with a number of indentations 26, which receive the end of the rod 27, which is inserted in the hollow lever-arm 22. Normally the rod 27 is withdrawn and the pawl-rin g is free to rotate within the chamber in the lower end of the lever 22; but when it is desired to operate the clutch-operating shaft to release the clutch the rod 27 is inserted and locks the pawl-ring and the lever 22, and the device operates as though the pawls were mounted directly upon the lever.

hat I claim is 1. In an elevator construction, a car, a guide engaged by said car and having a resilient rib, and a clutch on said car to engage and crimp said resilient rib.

2. In an elevator construction, a safety appliance comprising a clutch, and a track therefor, said track comprising abase and two 1011- gitudinal parallel ribs thereon arranged to b criniped by said clutch.

3. In an elevator construction, a safety appliance comprising a clutch on the car, and a track therefor, said track comprising a T- bar and two resilient plates mounted on opposite sides of the rib of said bar.

4t. In an elevator construction, a safety appliance comprisinga clutclnand atrack therefor, said track comprising a base and two longitudinal parallel ribs thereon arranged to be crimped by said clutch, and a lug on said car projecting into the space between said ribs.

5. An elevator construction comprising a car, a guide engaged by said car and having a resilient rib, a clutch on said car arranged to engage and crimp said resilient rib, and automatic means for operating said clutch.

6. An elevator construction comprising a car, a clutch therefor and a track having a resilient member arranged to be crimped by said clutch, said clutch comprising an abutment-piece and a lever opposite the same and means for actuating said lever, said means comprising a threaded shaft, a nut on said shaft arranged to engage said lever, a winding-drum on said shaft, and an endless rope arranged to normally move with the elevator and to bind when the car moves too fast.

7. A11 elevator construction comprising a car, a clutch thereon comprising a lever, a f the drum, and a track for said clutch, said threaded shaft, a nut working on said shaft track comprising aresilient member arranged :o andengaging said lever, and means for actuto be erimped thereby.

ating said shaft, said means comprising a drum on said shaft, a pulley 0n the stationary WALTER LASAR' portion, an endless rope winding about said \Vitnesses: drum and said pulley to stop the same auto- JAMES A. CARR, matically and thereby cause the turning of JULIA B. MEGOWN.

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