US1687654A - Elevator control system - Google Patents

Description

Oct. 16,1928. 4 1,687,654

' E. M. BOUTON ELEVATOR CONTROL SYSTEM Filed Feb. 16, 1922 WITNESSES: INVENTOR I [d f7. 5 7 n 1% ig! ou 0 ATTORNEY 1 ing sheave and the cables for operating th Patented 0a. 16, 1928.

v UNITED STATES PATENT OFFICE.

EDGAR; m. nou'roN, or EAST PITTSBURGH, PENNSYLVANIA, Assronon 'ro WESTING- nousn nnno'rnrc a MANUFACTURING COMPANY, A CORPORATION or PENNSYL- VANIA.

ELEVATOR CONTROL SYSTEM.

Application filed February 16, 1922. Serial No. 586,872.

' may be desired.

Another object of my invention is to provide a system wherein an elevator car or other device may be controlled with extreme accuracy within predetermined limits of motion.

Many systems of control have been employed in connection with elevators and hoists in an endeavor to secure accurate stops or landings, independently of the skill-of the operator. Such systems are, as a rule, rather complicated and, in some instances, not sufiiciently effective or satisfactory.

My invention is particularly adapted for use in connection with high-speed elevator machines of the traction type. which are generally understood as comprising a motoroperated driving-sheave and a secondary sheave. The hoisting cables are wrapped about the sheaves in such manner that effective traction is established between the drivcar. In addition to the standard elevator machine and the usual control apparatus, I provide an auxiiiary hoisting machine for connection, means oi an electro-magnetic cintch. to the secondary sheaves. My system of control is arranged for selectiveiy operatic the car by one or the other of these hoisting defines. The control of the main Easter is cied by means of the usual type ereas auxiliary motor is or pair of reversing that are recanted en the car acso i y came in elevator hatchway. ese are efiective to control the operathe e'ievator ear within predetermined travel, with respect to each floor level.

' lhe single figure of the drawing is a diagrammatic representation of circuits and apparatus embodying my invention.

The main hoisting motor, having an armature 1 and a field-magnet winding 2, is operatively connected to line conductors 3 and 4 through reversing switches 5 and 6. The

main driving-sheave 7 is mounted on the armature shaft. The usual form of electromagnetic brake 8 is provided.

A starting resistor 9 may be controlled by i an accelerating switch 11 in any well-known manner. A controlling switch, having an operating lever 12, is located within, and normally controls the operation of, the car 13. Auxiliary reversing switches 14 and 15 cooperate with a stationary contact mem ing 29 and an electromagnetic clutch 31, to

drive the secondary sheave 32. Either the main or the auxiliary motor may be employed for operating the elevator car-13;

In one instance, the sheave i operates as the driving member, that is, while the clutch 31 is released, whereas, when the sheave 32 is operated as the driving member, the clutch 31 is effective to transmit power from armature 17. In the latter case, the elecpositions by means of springs 19" tromagnetic brake 8 is released and the main armature l is driven idly, together withzthe by means or the hoisting cables that at the movements the elevator car.

"nxiliary reiay controls th'e'electroinaily closed reiay and acentrifugal governor 35, for controlim the electromagnetic brake 8. The centriaug algovernorfifi is operativeiy connected, in any convenient manner, to function in accordance with the" speed of the elevator car 13." the operation of my system will'be more clearly understood from thejfo'llowmg description. In normal operation, the elevator etic brake 28 ice-operates with a car 13 is governed, in a well knownmanner,

by the operating lever 12 of the car switch which controls the direction of rotation of the main armature 1 by means of reversing switches 5 and 6. This much of the operation is so well understood and so old in the art, that further. detailed description is considered unnecessary.. V It may be assumed, however, that the car 13 is Operating at normal speed and that the operator returns the lever 12 to its ino rative or illustrated position to effect a anding, substantiallylevel with the floor 23. If the car is moving upward and tends to stop below the level of the floor 23, the cam 22 ac* tuates switch member 16 to continue the u ward movement of the car, by means of t e auxilia hoisting mechanism and independently o the operator. .It may be assumed that the governor- switch members 36 and 37 respectively occupy the positions illustrated in thedrawing and which correspondto a ve "slow operatings eed. v

, auxiliary circuit for effecting u ward movement of the car 13 extends from t e line conductor 3 through conductor 38, the operat-' ing coil of relay 33, the operating coil of reversing switch 24, conductor 39, contact members 14 and 16, governor switch 37, carswitch members 41 and 42 and conductor 43 to-line conductor 4. The relay 33 closes'to establish a'circuit for the operatin coil of conductor 3- through conductors 38 and 44, relay 33 and the operatin coil of brake 28 p to line conductor 4, thereby effecting a release of the brake 28. Electromagnetic brake 8 is also'released by the energization of an auxiliaryoperatin coil 45, 'connectedin series relation with the armature 17, the circuit for which extends from line conductor 3 throu h resistor 26, switch 24,0 crating coil 45, re ays 33 and 34, armature 17 24 to line conductor 4. Power is su plied to the auxiliary armature 17 by the clbsure of up reversing-switch 24,-whereby, upon re lease of brake magnets 8 and 28, power is ap plied through the'clutch '31 for driving the sheaves 32 and 7. a

It is obvious that the auxiliary coil 45, which is in series relation witharmature 17 is energized in proportion to the elevator 10a and the current traversing the armature 17. With-light load, for example, the main brake 8 is not fully released and. mposes additional load on the auxiliary motor. Consequently, the auxiliary motor always operates under load and at a uniform speed.

It is also'obviousthat a shunt coil ma be emplo ed, inlieuof series coil 45, in w ich case t e main brake .8 will be fully released irrespective of load conditions the coil would be connected to' line conductors 3 and 4, through relays 33 and 34.- v

When the car13 has attained a level with the floor 23,'s'witchmember 14 returns to its normal or illustrated sition to interrupt the operating circuit th i electromagneticbrake 28, extending rom line and switch gagement until the car is substantially level rough contact mem-" ber 16, aspreviously traced. The switch 24 opens to interrupt the operating circuit for armature 17, and rela 33 opens to effect the application of thebra es 8- and 28.

A movable clutch member 46, during the operation just described, is maintained in engagement' with stationary clutch member 47 by means of a compression spring 48. How- 'ever, during normal operation of the elevator,

the clutch members 46 and 47 are disengaged 76 by means of an operating coil 49, which is ener ized simultaneously with the main operating coil 50 of the brake 8. As illustrated, these coilsare connected in series relation.

' When the car 13 is operating above a predetermined speed, governor switch 36 is closed and a circuit is established for an auxiliary coil 51, whichoperates inde endently of coil '49, for maintaining the clutc 31 inopbe ener 'zed through relay 34. The auxiliary clutch-' olding'coil 51 also is deenergized by the opening of governor switch 36, and 'the clutch 31 does not become effective as a driving member until the speed of the elevator car has been reduced to a proper value, corresponding to the operating speed of the auxiliary motor 20. In other words, the relative speeds of armature 17 and sheave 32 are controlled by means of the governor 35 prior to the engagement of clutch members 46 and 47 It is manifestly impractical to drive the auxiliary motor at a speed corresponding to the highest operating s eed of the elevator, for which reason the c utch mechanism is provided.

Referring again to the sloweed operation, it is evident that downwa movement of the car 13 is effected or continued upon the enga ement of contact members 15 and 16, as when the car tends to stop above the level of .the floor 23. In this case, the cam 22 maintains switch members 15 and 16 in enwith the floor 23, corresponding to its illustrated position. The downward movement ofthe car is efl'ect'ed by the closure of reversing switch 25 and relay 33, a circuit for the operating coils of which extends from line 125 conductor 3 through conductor 38, operating coil of relay 33, operating coil of switch 25, switch contact members 15 and 16, governorswitch 37, carswitch members 41 and 42 and conductor 43 to line conductor 4. All other 180 operating circuits are as previously described in connection with the upward movement of the elevator. i

It will be recognized that my system of control may be readily applied to any standard elevator equipment and lends itself to such applications in a very practicalvmanner. Assuming that the elevator is designed for a normal operating speed of say five hundred feet per minute, the auxiliary machine for driving the secondary sheave may be very small, to effect operation of the car at say 7 twenty-five feet per minute. The auxiliary machine'is not subjected to heavy strains, since these are borne by the main hoisting machine and the secondary sheave. The torque necessary for operating the car by means of the secondary sheave at the reduced speed is low, compared to that required of the main motor to operate the car at its normal speed. Also, in stopping, the

main brake is applied and assumes the major portion of the work necessary to'bring the elevator to rest.

I claim as my invention 1. The combination with an elevator and a main hoisting motor therefor, of leveling .means for sald elevator comprlslng an auxlllary motor and braking means for variably loading said auxiliary motor to secure uniform leveling operations of said elevator.

2. The combination with a main motor for operating an elevator ear and a brake therefor, of a coil independent of said motor

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