Mitsubishi Denki Kabushiki Kaisha

Shigehiko Suzuki

Kenzo Tachino

Hiroshi Kamaike

Narihiro Terazono

Satoshi Imaiida

Apparatus for monitoring the cage of an elevator for crime prevention including a connection establishing two-way voice communication between a telephone/television within the elevator cage and a similar device at a remote monitoring point. Communication is automatically established in response to a signal, such as generated by elevator call buttons, utilized in operation of the cage.

Apparatus for monitoring elevator cages for crime prevention

A rescue operating apparatus for an elevator has a device for transmitting a cage door open/close command from an elevator supervising section which receives notice regarding the trouble of the elevator and the stopping of the cage between floors, and an operation control device for controlling a door driver on the basis of a door open/close command from the command transmitting means to open/close the cage door thereby to confirm the full closure of the door and then control the elevator driver, thereby performing the rescue operation of the cage.

Rescue operating apparatus for elevator

An elevator remote-control method according to this invention consists in that, when a maintenance command has been received, a call-back program is executed which comprises a ring-off processing step of once disconnecting a telephone circuit, and a reconnection step of dialing a remote monitoring center to reconnect the telephone circuit, whereupon a program which conforms to the maintenance command is executed.

Elevator remote-control method

A method of and apparatus for controlling operation of an elevator at the occurrence of an earthquake. Estimated seismic intensity data is collected from a plurality of sources at different locations within a geographic region and transferred to an administration section; the geographic region is divided into zones of different seismic intensity based upon the transferred data; seismic intensity at the location of the elevator is assumed upon the occurrence of an earthquake on the basis of location of the elevator in the zones; whether the operation of the elevator is to be permitted is judged according to the assumed seismic intensity; and a trial run is commanded upon a judgement that operation is permitted, whereupon normal elevator operation is restored when the absence of any abnormality has been acknowledged upon travel during the trial run.

Method of and apparatus for controlled operation of an elevator system

A control apparatus for an elevator comprises a position detector responsive to cage movement, a non-volatile semiconductor memory for storing representation of cage position, and a microcomputer operated under program control for controlling the position detector to produce signals representing instantaneous cage positions and for continuously erasing and rewriting the contents of the non-volatile semiconductor memory based on the position detector signals. Thus, the stored contents can be reliably held even at the time of power failure, so that an expensive backup power source can be dispensed with.

Control apparatus for elevator

The present invention is an induction motor control system which prevents an excessive induced voltage across the thyristors providing DC braking control. The amount of DC braking torque is controlled by the time of application of the DC braking voltage to the induction motor through a phase-control capacitor which sets the time of firing the braking thyristors within each half cycle of the AC voltage. In a first embodiment the firing of all the braking thyristors is inhibited upon application of the DC braking control signal until the half cycle of the AC voltage associated with a predetermined braking thyristor. In a second embodiment the firing of a predetermined braking thyristor is inhibited during the half cycle of the AC voltage of the application of the DC braking control signal and the next succeeding half cycle. In both embodiments the braking thyristors are fired during their associated half cycle of the AC voltage thereafter to apply a continuing DC braking voltage to the induction motor.

Induction motor control system

In a three-phase AC voltage control circuit containing reverse parallel connections of a thyristor and a diode or reverse parallel connections of thyristors in at least two phases, each asymmetrical AC voltage obtained by applying a line voltage of the power source having 30 degrees of phase lead from that of the phase voltage of the power source in the phase containing the thyristor to each polarized delay circuit is used as the power source for a firing angle control circuit of the thyristor in the phase.

Three-phase AC voltage control circuit

The disclosed elevator speed control system accelerates an induction motor for an elevator car in accordance with a voltage dependent upon a differential signal between a command speed signal and the actual speed signal and passed through a saturation generator. The saturation generator issues a command for applying across the motor its rated voltage upon the closure of a normally open contact set disposed in it. The system includes a sensor circuit is responsive to the difference signal less than a predetermined magnitude to decrease an output from the saturation generator. Alternatively the sensor circuit may responds to a negative load on the motor exceeding a predetermined magnitude to decrease the output from the saturation generator.

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Inazawa, Japan

Shigehiko Suzuki