US1158255A - Automatic stop for elevators. - Google Patents

Description

P. L; IVIANLET.

AUTOMATIC STOP FOR ELEVATORS.

APPLICATION FILED SEPT-27, I91 I.

Patented Oct. 26, 1915.

I; YEW/655% Ewen- A win/76a PETER L. MANLIET, OF ST. PAUL, IVIIN'NESO'Ll-L.

AUTOMATIC sror non ELE ATORS.

Application filedSeptember 27, 1911.

To all whom it may concern:

Be it known that I, PETER L. MANLET, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Automatic Stops for Elevators, of which the following is a specification.

My invention relates to improvements in automatic stops for elevators and its principal object is to provide a positive means for throwing off the power operating the elevator when the elevator car or the counterweights connected with it are carried beyond a predetermined point in their respective guide tracks.

It frequently happens that an elevator operator is unable to shut ofl his power in time to prevent the car from rising too high in the elevator shaft, damaging the car and shaft and tending to break the elevator cable through the momentum of the counterweights. In a similar way the car may require automatic stopping at the bottom of its path to prevent damage to the car and counterweights. Numerous devices are in use intended to apply brakes to the elevator car when it passes beyond its upper or lower limits, but which are frequently slow to operate or entirely ineflective. The device which I have invented operates positively and instantly to out 01f the power operating the elevator and utilizes the electric power most efliciently to brake the motor.

In the drawings with which I have illustrated my invention and which form part of my specification, Figure 1 is a view of an elevator connected by my device with a main line switch and illustrating the use of a spring; Fig. 2 is a diagrammatic view illustrating the application of my device to a magnetic brake by means of a three pole switch; Fig. 3 is a diagrammatic view illustrating my device in connection with an armature brake, and Fig. 4 is an elevation of the switch shown in Fig. 3.

In Fig. 1 I have illustrated a main curcuit switch A supplyingpower to the motor B shown in Fig. 2 operating an elevator car E which moves in the car track C. A counterweight guide D is shown in which slide thecounterweights 2 connected to the elevator car in the ordinary manner by cables 3. The 'des D are formed with grooves 4 carrying theends of the counter-Wei hts 2. The track also has a groove 5 or equivalent Specification of Letters Patent.

Patented @ct. 26, 1915.

Serial no. 651,628.

' tremity-of'the path of the elevator car and carrying a flexible cord or chain 7 connect ing with a similar peg 6 in the groove 4 of the guides D. Pegs 6 are similarly positioned in the grooves 4 and 5 at the lower limit of the pathof the elevator car and counterweight and connected by a chain 7 with a chainS which extends vertically and has pulleys 9 at its extremities running freely in the loops of the chains 7 and conmeeting them in such a way that the releasing of any peg 6 produces slack in the chain 8. The motor B' has a friction wheel 10 in connection with it and brake arms 11 pivoted on a support 12 to operate the band brake 13 on the friction wheel 10 to stop the elevator car connected with it. The brake arms 11 are operated by solenoids 14 and opposed springs 15 mounted on them, the

solenoids 14 normally holding the band brake 13 out of contactwith the friction wheel 10 and the springs 15 tending to tighten the brake on the wheel when the solenoids become inoperative.

Referring to Fig. 2 the switch A has connected with it main line conductors 16 and conductors 17 connecting the motor B and the solenoids 14 in parallel with each other and in series with the controller 18 which is positioned in the elevator car. A chain 19 connects with a spring 20, passes between suitable pulleys 21 and terminates in a pulley 22 running freely on the chain 8. The

chain 19 holds the spring in tension and released by the breaking of any one of the pegs 6 and contracts. The opening of the switch A breaks the circuits through the conductors 16 and 17 thus stopping the application of power to the motor B and applying the brake to the friction wheel 10.

In Figs. 3 and 4 I have illustrated an alternative construction of my invention in which the main line conductors 16 connect Wil iliary blade 31 attached to one of the blades 30. In the closed position of the switch the current passes through conductors 32, 33 and 34 and the resistance 35. is open the main line circuit is broken and the motor B rotating under its own momentum generates current. The blade'31 makes contact with the conductor 36 closing the circuit from the motor through conductors 33, 35, 36 and 32, producing an armature brake stopping the action of the motor almost instantly. It is evident that a suitable weight may be used in place of the spring 20 described and that other power means besides the electric power described in the specification may be used in connection with the electrically operated brake mechanism shown.

In accordance with the patent statutes I have described the principles of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof but I desire to have it understood that the construction shown is only illustrative and that the invention can be carried out by other means and applied to uses other than those above set forthwithin the scope of the following claims; I

Having described my invention, what- I claim as new and desire to protect by Letters Patent is 1. In adevice of the class set forth, an elevator car operable in a fixed path, an electric motor adapted to operate said car, a brakefor said motor, means for'operating said brake, resilient means arranged to urge the operating means into position to cause the setting of said brake, and frangible means holding said resilient means under stress and the operating means inactive and positioned in a path to be broken by said car and to release the resilient means when the car moves beyond its normal travel.

When the switch I 2. In a device of the class set forth, an elevator car operable in a predetermined path of travel, a frangible stop positioned in the path of said car, a motor adapted to operate said car, a switch adapted to control said motor, means for connecting said Stop and switch to operate the latter when said stop is broken by said car moving beyond its normal travel, and an electric brake connected with said switch and adapted to be automatically operated by the opening of said switch.

3. In a device of the class set forth, a guideway, an elevator car operating in said guideway, an electric motor adapted to opcrate said car, frangible means positioned in said guideway in the path of said car adjacent the limit of its normal travel, a brake for said car, means for setting said brake, electric means for holding said brake out of operation, a source of power connected with said electric means, means for disconnecting said electric means from said source of power, and a connection between said frangible means and said means for disconnecting said power, whereby upon the breaking of said frangible means by said car said brake is adapted to stop said car.

4. In a device of the classset forth, an elevator car movable through a normal path of travel, means for operating said car, a friction brake on said operating means, a solenoid mounted in connection with said brake adapted when energized to hold said brake out of operation, an electrical switch connected with said solenoid, and a frangible stop in connection with said car adapted to be broken when said car passes a limit of its normal travel and cause the opening of said switch and setting of said brake.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

PETER L. MANLET. Witnesses:

H. L. FISCHER, PAUL S. SMITH.

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