Safties for elevator hoist motor control having high gain negative feedback loop

Claim 2

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional over said performance parameter signal for disabling a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parameter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator and to move the elevator at constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means for controlling the operation of said hoist motor in accordance with said error signal; and means responsive to an error signal representing a predetermined excess of said performance parameter signal over said command signal and responsive to an error signal representing a predetermined excess of command signal over said performance parameter signal for disabling the response of said motor to said error signal whereby said performance parameter signal is confined within predetermined magnitudes of said command signal during acceleration, deceleration and constant velocity operation of the elevator along its path of travel.

Claim 3

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parAmeter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means to amplify said error signal to control the operation of said hoist motor; and means responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for disabling the response of said motor to said amplified signal, whereby said performance parameter signal is confined within predetermined magnitudes of said command signal during acceleration, deceleration and constant velocity operation of the elevator along its path of travel.

Claim 4

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parAmeter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means to amplify said error signal to control the operation of said hoist motor; and means responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for disabling the response of said motor to said amplified signal, whereby said performance parameter signal is confined within predetermined magnitudes of said command signal during acceleration, deceleration and constant velocity operation of the elevator along its path of travel.

Claim 5

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parameter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means for controlling the operation of said hoist motor in accordance with said error signal; and means responsive to an error signal representing a predetermined excess of said performance parameter signal over said command signal and responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for actuating an indicator.

Claim 6

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parameter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means for controlling the operation of said hoist motor in accordance with said error signal; and means responsive to an error signal representing a predetermined excess of said performance parameter signal over said command signal and responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for actuating an indicator.

Claim 7

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parameter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means to amplify said error signal to control the operation of said hoist motor; and means responsive to an amplified signal representing a predetermined excess of said performance parameter signal over said command signal and responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for actuating an indicator.

Claim 8

A hoist motor control for an elevator having a guided path of travel comprising a hoist motor; means for generating a signal proportional to a performance parameter of said hoist motor as it drives the elevator along its path of travel; means for generating a performance parameter command signal to command said hoist motor to accelerate the elevator, to decelerate the elevator, and to move the elevator at a constant velocity along its path of travel; means for comparing said performance parameter signal and said command signal to develop an error signal; means to amplify said error signal to control the operation of said hoist motor; and means responsive to an amplified signal representing a predetermined excess of said performance parameter signal over said command signal and responsive to an amplified signal representing a predetermined excess of said command signal over said performance parameter signal for actuating an indicator.

Claim 9

A combination in accordance with claim 1 including means responsive while said elevator is stopped to enable said disabling means and responsive while said elevator is moving to render said disabling means ineffective.

Claim 10

A hoist motor control for an elevator including a car serving a plurality of landings comprising a hoist motor; means for stopping said car at one of said landings; means for sensing a misalignment of said car with said landing at which it is stopped; means for generating an elevator performance parameter signal proportional to a performance parameter of the elevator; means for generating a performance parameter command signal; means for comparing said performance parameter signal and said command signal to develop a performance parameter error signal for controlling said hoist motor, means for actuating said command signal generator in response to a misalignment of said car with said landing at which it is stopped to generate a signal tending to correct said misalignment; and means responsive to an error signal exceeding a predetermined level during the operation of said misalignment responsive control of said hoist motor for disabling the response of said motor to said error signal. &. A combination in accordance with claim 1 wherein said performance parameter is hoist motor speed; and includiNg means amplifying said error signal; and means applying said amplified signal to control said hoist motor.

Claim 11

A combination in accordance with claim 2 wherein said performance parameter is hoist motor speed.

Claim 12

A hoist motor control for an elevator including a car serving a plurality of landings, said control comprising a hoist motor; means to stop said car at said landings; means to sense misalignment of said car with a landing at which it is stopped; means for generating a signal proportional to an operating parameter of said elevator; means for generating an operating parameter command signal; means for comparing said operating parameter signal with said command signal for producing an error signal; means to amplify said error signal; means to apply said amplified signal to said hoist motor to control said motor, first check means responsive to an error signal exceeding a first level; second check means responsive when said elevator is stopped at a landing to an amplified signal in excess of a second level; means to actuate said command signal means to issue a signal tending to align said car with a landing at which it is stopped in response to said sensing means, third check means effective while said actuating means is responsive, said third check means being responsive to an amplified signal in excess of a third level; and means responsive to the response to an excessive level of any of said check means for disabling the response of said motor to said amplified signal.

Claim 13

A hoist motor control for an elevator including a car serving a plurality of landings, said control comprising a hoist motor; means to stop said car at said landings; means to sense misalignment of said car with a landing at which it is stopped; means for generating a signal proportional to an operating parameter of said elevator; means for generating an operating parameter command signal; means for comparing said operating parameter signal with said command signal for producing an error signal; means to amplify said error signal; means to apply said amplified signal to said hoist motor to control said motor, first check means responsive to an error signal exceeding a first level; second check means responsive when said elevator is stopped at a landing to an amplified signal in excess of a second level; means to actuate said command signal means to issue a signal tending to align said car with a landing at which it is stopped in response to said sensing means, third check means effective while said actuating means is responsive, said third check means being responsive to an amplified signal in excess of a third level; and means responsive to the response to an excessive level of any of said check means for disabling the response of said motor to said amplified signal.

Claim 14

A combination in accordance with claim 1 including an alternate motor control effective upon the disabling of the response of said motor to said error signal to continue operation of said motor in response to said alternate motor control.

Claim 15

A combination in accordance with claim 1 including an alternate motor control responsive to said command signal upon the disabling of the response of said motor to said error signal to continue operation of said motor in response to said alternate motor control.

Claim 16

A combination in accordance with claim 2 including an alternate motor control effective upon the disabling of the response of said motor to said amplified signal to continue operation of said motor in response to said alternate motor control.

Claim 17

A combination in accordance with claim 2 including an alternate motor control responsive to said command signal upon the disabling of the response of said motor to said amplified signal.

Claim 18

A combination according to claim 1 wherein said hoist motor is a direct current motor, said combination including a direct current generator supplying a variable voltage to the armature of said hoist motor; said generator having a shunt field divided into at least two portions; a first portion of said shunt field of said generator being connected to receive said command signal; a second portion of the shunt field of said generator being connected to receive said error signal and said disabling means interrupting the application of said error signal to said second portion of said shunt field.

Claim 19

A combination according to claim 2 wherein said hoist motor is a direct current motor, said combination including a direct current generator supplying a variable voltage to the armature of said hoist motor; a shunt field for said generator divided into at least two portions; a first portion of said shunt field of said generator being connected to receive said command signal; a second portion of said shunt field of said generator being connected to receive said amplified signal; said disabling means interrupting the application of said amplified signal to said second portion of said shunt field.

Claim 20

A combination according to claim 2 including means responsive while said elevator is stopped to enable said disabling means.

Claim 21

A combination according to claim 2 including an elevator car driven by said hoist motor, closure means for said car, means sensing the opening of said closure means, and means responsive while said closure means is open to enabLe said disabling means.

Claim 22

A combination according to claim 1 including means amplifying said error signal; means applying said amplified signal to control said hoist motor; and means responsive to an amplified signal in excess of a predetermined level for disabling the response of said motor to said error signal.

Claim 23

A combination according to claim 1 including a generator supplying power to said motor; a shunt field for said generator; said means for controlling said hoist motor supplying power to said generator shunt field; and said disabling means disconnecting said controlling means from said generator shunt field.

Claim 24

A hoist motor control for an elevator comprising a hoist motor; means for generating a signal proportional to an actual performance parameter of said elevator; means for generating a performance parameter command signal; means for comparing said performance parameter signal and said command signal to develop an error signal; means for controlling the operation of said hoist motor in accordance with said error signal; and means responsive to a rate of change of one of said signals at a rate in excess of a predetermined level for disabling the response of said motor to said error signal.

Claim 25

A hoist motor control for an elevator comprising a hoist motor; means for generating a signal proportional to an actual performance parameter of said elevator; means for generating a performance parameter command signal; means for comparing said performance parameter signal and said command signal to develop an error signal; means for controlling the operation of said hoist motor in accordance with said error signal; and means responsive to a rate of change of one of said signals at a rate in excess of a predetermined level for disabling the response of said motor to said error signal.

Claim 26

A combination according to claim 20 wherein said one signal is that proportional to said actual performance parameter.

Claim 27

A combination according to claim 21 wherein said performance parameter is velocity and said rate of change of said performance parameter is acceleration. 54

Claim 28

A combination according to claim 22 including manually operable emergency stop means for said hoist motor, whereby excessive rates of change of motor velocity are imposed and means responsive to the reset of said emergency stop means for resetting said disabling means whereby said motor is rendered responsive to said error signal.