US873495A

US873495A - Elevator safety appliance.

Info

Publication number: US873495A
Application number: US36068907A
Authority: US
Inventors: Samuel Bruce
Original assignee: Individual
Current assignee: Individual
Priority date: 1907-03-05
Filing date: 1907-03-05
Publication date: 1907-12-10
Anticipated expiration: 1924-12-10

Description

ELEVATOR SAFETY APPLIANCE.

APPLICATION FILED MAR. 5, 1907.

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SAMUEL BRUCE, OF HELVETIA, PENNSYLVANIA.

ELEVATOR SAFETY APPLIANCE.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed March 5. 1907. Serial No. 360,689.

To all whom it may concern:

Be it known that I, SAMUEL BRUCE, a citizen of the United States, residing at Helvetie, in the county of Clearfield and State of Pennsylvania, have invented new and useful Improvements in Elevator Safety Applianoes, of which the following is a specificatlon.

The invention relates generally to an improvement in elevators, and particularly to a safety appliance therefor adapted to automatically lock the elevator cage or platform against movement in a downward direction in the event of breakage of the supporting cable.

The main object of the resent invention is the provision of safety liivers operatively connected to the supportin cable and normally maintained by the ifting strain on said cable in inoperative or non-engaging position, the construction including an automatically operable element serving, upon the breakage of the supporting cable, to project the safety levers into locking engagement with the elevator slides, and thereby lock the elevator against further movement in a downward direction.

The invention will be described in the following specification, reference being bad particularly to the accompanying drawings, in

which Figure 1 is a perspective view illustrating the application of my improved safety a pliance, Fig. 2 is a view in elevation part y in section of the same, the safety levers being illustrated in looking or elevator supporting positions, Fig. 3 is a perspective view of one of the safety levers, Fig. 4 is a partial perspective of a slightly modified form of safety lever.

Referring particularly to the drawings, the elevator structure with which my improvement is designed to cooperate may, for the purposes'of the present invention, be said to comprise frame timbers 1 disposed in spaced relation in the well, and carrying on their inner or proximate surfaces the slides 2 on which the elevator is guided in movement. The elevator cage or car' comprises a platform 3 secured to uprights 4 designed to bear against the respective slides, said uprights being connected at their upper ends by a Guide plates are preferably secured .to the sides of the uprights to overlie and bear against the slides 2 to insure the proper travel of the elevator during operation. The car is elevated and lowered through the medium of an operating cable 7, terminally secured to a clevis 8, which in turn is connected to the car through the medium of elevator chains 9, the car engaging ends of which are preferably connected to the cross beam adjacent the respective ends of the latter.

The detailed structure described is intended to illustrate any desired form of elevator and operating-parts therefor, as such structure forms no material part of the present invention and may, therefore, be changed or varied in any desired manner.

The present invention is directed primarily to a safety appliance, in the use of which the car will be automatically locked against further descent in the event of breaking of the supporting cable 7.

In detailed structure the safety appliance of the present invention includes a s ring frame 10, comprising an approximate y U- shaped strip of metal of appropriate strength, the terminals of the arms of which are secured to opposing surfaces of the cross beam at points about centrally of the length of the latter. The spring frame is of such size that in this position the cross bar 11 thereof is arranged some distance below the lower surface of the cross beam and extends transverse the length thereof, as clearly shown in Fl 1. i

ll draw-bar 12 is mounted for free sliding movement in a slotted opening 13 formed in the cross beam, the upper edge of the bar be- .ing formed with an upwardly (projecting ear 14 for the reception of one en of the bridle chain 15, the o posite end of which is connected to the c evis 8. The lower edge of the draw-bar is formed with a depending ear 16 to which is connected one end of a tension member, referably a coil spring 17, the o posite end of which is connected to a tie bo t 18 adapted to be loosely passed through an opening in the cross bar 11 of the spring frame, and terminally threaded to receive ad justing nut-19 and a lock nut 20 beyond said cross bar 11.

Safety levers 21 are pivotally connected to opposing points of the draw-bar, each of said levers comprising a suitable length of material preferably gradually reduced in transverse dimension toward the free end. The relatively inner or connected end of each lever is preferably slotted to provide spaced ears 22 adapted to embrace the edge of the tions.

draw-bar to insure a more substantial connection. The free ends of the levers are reduced to a comparatively thin edge and formed with a series of teeth 23, said levers adjacent their free ends being slightly defiected from the normal plane of the lever to provide an engaging portion 24.

The uprights 4 of the car structure are formed at appropriate points with slots 25, preferably inclining downwardly toward and alined with the respective slides 2. In vertical dimensions the slots 25 are somewhat larger than the engaging ends 24 of the levers, the inclination of the upper wall of the slots corresponding to the inclination of the upper surfaces of the engaging ends 24, for a purpose which will presently appear.

In assembling the safety appliance for use, with the parts constructed and arranged as described, the bridle chain 15 is so adjusted as to elevate the draw-bar to normally maintain the free or tooth ends of the safety levers out of engagement with the slides 2. Through the medium of the nuts 19 and 20 the tie bolt 18 is then adjusted so as to put the spring 17 under the desired tension. With the parts thus arranged, the car is free to be elevated or lowered in the usual manner, and in the event of breakage or other rupture of the cable 7 the spring 17 instantly operates to draw downward the draw-bar 12, and thereby project the free ends of the levers into engagement with the slides 2. As the pivot ends of the levers are supported some distance above the slots 25, it is obvious that the engaging portions 24 of the levers will, in the normal positions of the parts, rest upon the lower wall of the slots 25, and as the spring operates said levers to force them into engagement with the slides a comparatively free movement will be permitted. said engaging ends 24 enabling them to effectively seat themselves in engaging posi- As the downward movement of the car continues and the upper walls of the slots engage the free ends of the lever, the inclination of said walls corresponding to the in clination of the engaging lever ends will more firmly seat said levers in slide engaging position. The car is thus effectively locked against further deseentand may be conveniently unlocked by simply elevating the car through any desired connection.

In Fig. 4 is illustrated a slightly modified form of lever engaging end, whereby the cooperating teeth 26 are arranged in spaced rows extending transverse the length of the lever. This particular form is designed for use with heavy cars or with cars adapted to support extreme loads, as the double row of teeth will afford a more certain operation and prevent disengagement through the breakage of the teeth of one row. In both the preferred. and modified form the engaging ends of the levers may, if desired, be treated to render them exceedingly hard, whereby they are adapted for engagement with metal slides as well as wooden slides.

While preferring the details of structure herein described and shown it is obvious that various changes and modifications may be resorted to without materially affecting the function or purpose of the invention, and I wish it to be understood that I consider as within the spirit of the present invention all such changes and variations as may fall wi thin the scope of the appended claims.

Having thus described the invention what is claimed as new, is:

1. The combination with an elevator car including a cross beam provided with an. opening, of a U-shaped. frame secured to the cross beam, a draw bar slidably mounted in the opening of the cross beam, an elevating cable secured to the draw bar, safety levers pivotally secured to said draw bar, a tie bolt adjustably secured to the cross bar of the U- shaped frame, and a spring secured at one end to the draw bar and at its other end to the tie bolt.

2. The combination with an elevator car including a cross beam provided with an opening, of a U-shaped frame having the terminals of its arms secured to opposite sides of the cross beam, a draw bar slidably mounted in the opening of the cross beam and between the arms of the U-sh aped frame, an elevating cable secured to the draw bar, safety levers pivotally secured to said draw bar, a tie bolt adjustably secured to the cross bar of the U- shaped frame, and a spring secured at one end to the tie bolt.

In testimony whereof, I allix my signature in presence of two witnesses.

SAMUEL BRUCE. Witnesses:

D. IN. GOULD, JOHN L. FLETCHER.