US1358734A - Safety device for elevators - Google Patents

Description

A. HEISLER. SAFETY DEVICE FOR'ELEVATORS.

APPLICATION FILED MAR- 31,1920- Patented Nov. 16, 1920.

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UNITED STATES PATENT OFFICE.

AARON HEISLER, 01F PITTSBURGH, PENNSYLVANIA.

Specification of Letters Patent.

Patented Nov.16, ieeo.

Application filed March 31, 1920. Serial No. 370,110.

To aZZ'w 7mm it may concern Be it known that I, AARON HEISLER, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Safety Devices for Elevators, of which the following is a specification. I

This invention relates to safety devices for electric elevators in which a switch, carried by the cage and inserted in the electric circuit which actuates the lifting 1nechanism, is controlled by means of a projection arranged in the elevator well; and it consists in the novel construction and com-. bin-ation of the parts hereinafter fully described and claimed.

In the drawings, Figure 1 is a diagram of an elevator provided with a safety at tachment according to this invention. Fig. 2 is a side view of the safety device drawn to a larger scale and showing the casing in section. Fig. 3 is a front view of the device shown in Fig. 2.

The elevator is an electric elevator oi any approved construction having a cage 2 which is slidable vertically in an elevator well 3, and which is actuated by lifting mechanism of any approved kind. A casing sis secured in the elevator cage, and incloses a switch having a stationary and insulated contact member 5. A switch lever 6 is pivoted in the casing on a pin 7 and it carries an insulated contact member 8. The contact members are inserted in the electric circuit 9, and when in contact they permit the current to pass to the electric lifting mechanism. /Vhen the contact members are separated the circuit broken, and the lifting mechanism is stopped, but the circuit may be so arranged that the current 18 only partially cut off from the lifting mechanism so that the latter is caused to operate slowly.

The switch operating mechanism on the cage is actuated by a stationary cam or projection 10 secured to one side of the well 3 at any suitable point. This camis preferably formed of a curved spring which is curved outwardly and secured to the well at each end. A cam or eccentric 12 is mounted on a pin 14 in the casing 4, anda ratchet toothed wheel 15 is secured to one side of this cam. The cam 12 has recesses 16 in its periphery, and 17 is a spring check pawl which is secured to the casing, and which engages with the said recesses. Any other approved check mechanism may however be used in carrying out this invention provided it will prevent the cam 12 from being improperly moved.

lever 18 is pivoted on the pin 14:, and 19 1s a pushing pawl pivoted to one end of the lever and engaging with the teeth of the wheel 15. The cam 12 is arranged to one side of the, switch lever 6, and engages with it when partially revolved. The other end portion of the lever 18 has a longitudinal slot 20, and 21 is a slide which is arranged horizontally, and which works back and forth on a guide 22 secured to the casing. An arm 24 projects vertically from one; end portion ofthe slide and has a pin 25 at its upper part which engages with the slot 20. The other end portion of the slide 21 carries a roller 26 which is mounted on a pin 27,

Two curved arms 30 are provided, and are pivoted at their opposite ends to the casing 4 or other suitable support, by pins 31. The adjacent end portion of the arms 30 have slots 32 which engage with the pin 27, and the arms normally position and support the outer end portion of the slide which projects through an opening 33 in the side of the casing a. The roller 26 engages with the cam or projection 10, and when the slide is pushed back by the cam, the switch lever is operated and the contact members are separated.

Each elevator can be provided with a series of safety devices similar to those hereinbefore described, and the cams or projec tions lOare put at suitable points in the elevator well so as to stop the cage automatically at any desiredlevels, and to make it move slowly at predetermined points, such as when the cage approaches a landing place.- The switch mechanisms are preferably arranged side by side in the cage when a plurality of them is. provided, but each mechanism is arranged towork independently of the others. The ratchet toothed wheel '15 need not have teeth all around its periphery, and a single tooth engaged by the pawl 19 would be effective to open the switch. The provision of a series of teeth however enables the device to be set and adjusted to suit the requirements of different elevators, or diiferently located projections 10' in the same elevator shaft or well. When the elevator cage has been stopped automatically by the safety device, the elevator man in the cage re-sets the ratchet toothed wheel and pawl by hand to their original positions stops, which will occur on in order that the cage may again beoperated. The check pawl 17 prevents the switch from closing when the roller '26 is moved past the projection lO before the cage high speed elevators such as are now used in high buildings. 7

What I claim is:

-1. Ina safety'device, an electric switch adapted to be secured in an elevator cage and provided with a :pivoted switch lever, av stationary projection adapted to be secured in the elevator/we'll, a cam for moving the said lever to open the switch, a cam operating lever pivoted concentric with the earn, a :pawland iratchet'mechan sm operatlvely connecting the said cam operating lever with the cam, vided witha roller atone end tor engaging withithe:saidzproj ection and having its-other end operative'lyiconnected with "the cam op erating lever, and a spring which normally projects the slide so that its roller will engagte with the said projection.

a safety device, an electric switch 7 provided with a pivoted operating "lever and adaptedto be carried by an electric a horizontal slide ;pro-- V the outer end portion of the said normally holding," tin position to be en- Y gaged by the said-projection cage, astationary projection adapted to be secured in the elevator well, a vrevolulole cam for operating the switch lever, a toothed wheel secured to'the. said cam, a lever pivoted concentric with the toothed, wheel and provided'with a pawl for engaging with its teeth, and a horizontal slide which is pushed back by the said projection and ates the last said leven 3. In a safety device, an electric switch provided with a pivoted operating'lever and adapted which opera stationary pro ection adapted to be se pivoted arms having their adj acent send portions pivotal-1y and "slidably connected with In testimony whereof I haven fixed :rny

signature. V

AARON HEISLER.

to bejcarried byan elevator cage;

is 1 operatively connected I slide and

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