Mitsubishi Denki Kabushiki Kaisha

Masashi Yonemoto

Ryuichi Kajiyama

Eiki Watanabe

Hiroyasu Itoh

An elevator safety device in which a counterweight cam is attached to the counterweight and top terminal landing final limit switches are disposed below the bottom terminal landing of the hoistway so that it is operated by the counterweight cam. The top terminal landing final limit switches only need to be provided in accordance with the counterweight buffer stroke, regardless of to what extent the car has been flung upward, with the result that fewer final limit switches are required.

Elevator safety device

A safety device for an elevator which detects a trouble of the control device quickly to apply an emergency brake, thereby to ensure the safety of the people in the cage. The elevator safety device is so designed that the harmonic wave component produced by an inverter is detected with the aid of a band-pass filter, and when the harmonic wave component thus detected becomes abnormal, an emergency stop instruction is produced.

Safety device for elevator

An elevator control apparatus comprises a torque control device for calculating a torque command for a motor for hoisting an elevator cage, a brake which operates in response to a braking command so as to restrain the motor, a brake abnormality detector adapted to operate when a difference between a maximum value and a minimum value of the torque command is less than a predetermined value, and a brake abnormality output circuit which delivers a predetermined signal when an inferior release of the brake has been detected by the operation of the brake abnormality detector.

Elevator control apparatus

An apparatus for controlling an A-C powered induction motor for an elevator cage, said apparatus comprising a rectifier for converting 3-phase A-C power into D-C electric power, an inverter connected to the rectifier for converting the D-C power into A-C power of variable voltage and variable frequency, a current detector connected to detect input current of the inverter, a power detector for detecting power supplied to the inverter based upon an output of the current detector, a control unit for generating a command signal to control the inverter in accordance with slip of the induction motor as determined by the power supplied to the inverter, and a correcting unit operable responsive to the power detected by the power detector for correcting the slip of the motor to maintain the power supplied to the inverter at predetermined values.

Apparatus for controlling an A-C powered elevator

In an elevator driven by an induction motor and having a slip control device for generating a slip frequency command signal on the basis of an error between a speed command value and a running speed value of the induction motor so as to control a VVVF type inverter which in turn provides a corresponding alternating current of variable voltage and frequency, the inverter having a smoothing capacitor on a D-C side thereof, a control apparatus for stabilizing torque of the induction motor by smoothly changing operation of the induction motor from a powering mode to a regenerative mode, the control apparatus comprising a current detector for detecting charging current of the smoothing capacitor having a portion for detecting polarity of the slip frequency command signal and a unit responsive to the charging current detected by the current detector and the slip frequency command signal generated by the slip control device for changing operation of the induction motor from the powering mode to the regenerative mode only when a voltage value based on the charging current has exceeded a preset reference voltage value after a negative sign of the slip frequency command signal is detected by the polarity detection portion.

Control apparatus for elevator

A magnetic flux detecting coil for detecting a magnetic flux in the air gap between the stator is provided in the stator and rotor of an induction motor, the actual value of the secondary winding crossing magnetic flux is calculated on the basis of the detected output of the detecting coil, this value is compared with the secondary winding crossing magnetic flux command value to correct the secondary winding resistance value, thereby controlling to correct the slip frequency. Thus, the torque produced by the motor can be stabilized irrespective of the temperature rise of the motor.

Apparatus for operating an elevator

An apparatus for controlling an elevator having an induction motor for lifting the cage, a speed instruction device which produces a running speed instruction signal for the cage, a speed controller which generates a torque instruction for the induction motor, a current controller which produces a primary current for the induction motor to control it, a first speed detector which is coupled to the induction motor via a mechanism that increases the input speed to the detector and which feeds speed detection signals back to the speed controller, and a second speed detector which is directly coupled to the rotary shaft of the induction motor and which supplies speed detection signals to the current controller.

Apparatus for controlling elevators

An apparatus for controlling the arrival of an elevator cage at a target elevator floor in which the elevator cage is not stopped at an intermediate position between adjacent floors even when a detection displacement occurs when the actual cage position and a calculated cage position do not correspond wherein said cage is stopped at said target floor when it is detected that said actual cage position is less than or equal to said calculated elevator position and said cage is stopped at an adjacent floor to said target floor when said calculated cage position is greater than said calculated cage position.

Apparatus for controlling the arrival of an elevator cage at an elevator

An apparatus for decelerating an elevator at a terminating floor having a plurality of terminating detectors successively provided in the vicinity of the terminating floor for generating a terminating deceleration command value gradually decreasing upon operation of the detectors when the cage of the elevator approaches the terminating floor which comprises; a pulse generator for generating pulses corresponding to the moved distance of the cage; memories for storing the distances from the terminating floor to said respective terminating detectors; a counter for setting the distance information of the detectors of said memories upon operation of the detectors and counting the output pulses of said pulse generator, thereby subtracting the pulses from the set value; and a distance-to-speed converter for calculating the terminating deceleration command value corresponding to the output of said counter.

Apparatus for decelerating elevator at terminating floor

An apparatus for controlling an elevator, which comprises a managing first electronic computer for managing the service of the start and stop of an elevator cage and a controlling second electronic computer for controlling the speed of the cage in accordance with a command from said first computer, wherein when the managing first computer becomes defective, the cage is conveyed to the nearest floor by the controlling second computer and when the second computer becomes defective, the cage is conveyed at a low speed to the nearest floor by the first computer and a manual operating circuit. Therefore, regardless of which of the first and/or second computers become defective, the cage can be automatically operated to the nearest floor and the passengers in the cage can be rescued.

Apparatus for controlling an elevator

An elevator speed instruction generating system using an electronic computer to generate speed instruction data comprises a pulse generator adapted to generate a pulse whenever the cage runs a predetermined distance, a counter for subjecting the pulse thus generated to addition and subtraction according to the travelling direction of the cage, and memory means provided in the electronic computer for storing acceleration and deceleration instruction data. Acceleration instruction data are read out of the memory means every predetermined time in the acceleration operation, and in the deceleration operation deceleration instruction data corresponding to the differences between the absolute position of a destination floor and outputs of the counter are read. Adjustment of the elevator, which is required when it is installed in different buildings, can be achieved merely by changing the data stored in the memory means.

Elevator speed instruction generating system

A method for controlling the movement of an elevator cage in which a difference between first and second speed instruction values is made constant irrespective of speed so that no shock force is applied to the cage at a time of switching between speed instruction values. A predetermined distance is added to a remaining distance of the age to a target floor. A modified second speed instruction value corresponding to the resultant distance is compared with the first speed instruction value, and when this difference becomes smaller than a predetermined value, a switching preparation instruction is issued. The elevator is operated at a speed determined by the first speed instruction value until a predetermined period of time after the switching preparation instruction after which the elevator is operated in accordance with the second speed instruction value.

Speed instruction generating device for elevator

An elevator relevelling control apparatus for controlling the movement of an elevator car (11) such that when the car is misaligned with the landing position of a selected landing floor, the car is restarted and brought into alignment. A traction motor (M) is controlled by a landing means (1) which generates a speed command signal (1a) of a magnitude which increases linearly with the extent of misalignment. First and second position detecting devices (15, 16, 17, 18) are provided in the hoistway to detect misalignment from the landing position by a first or second predetermined distance, respectively. The car is provided with load detecting means (12) for detecting whether or not the car is overloaded. If the load detecting means (12) detects that the car is not overloaded, and a switching device (15, 16) detects that the car is misaligned by a first predetermined distance, a speed command signal (1a) of suitable magnitude is supplied to the traction motor (M), thereby effecting relevelling. If, on the other hand, the car is detected to be in an overloaded state, and a switching device (17, 18) detects that the car is misaligned by a second, greater, predetermined distance, a speed command signal of larger magnitude is supplied to the traction motor (M), whereby the relevelling operation can be commenced with a torque greater than that applied when the car is not overloaded.

Elevator relevelling control apparatus

A dc voltage is applied to an R-C element through a Bootstrap type linearly charging circuit to form a command speed voltage smoothly and linearly increased from its null magnitude to a constant magnitude for the acceleration of an elevator car. Upon decelerating the car, the dc voltage is decreased stepwise by successively opening serially interconnected contact sets coupled to a shortcircuit resistor and applied to a unidirectional R-C element including a diode through the linearly charging circuit. An output from the element is coupled to the stepped voltage through an R-C discharge circuit to produce from the element a command speed signal smoothly and linearly decreased to its null magnitude.

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Inazawa, Japan

Masashi Yonemoto