Abstract: Each car controller (10) in a multicar elevator system provides two serial asynchronous full duplex I/O channels to communicate with the next and previous car controllers. These two channels allow the transmission of a message in two opposite directions (32,34) on a communications ring. A single interruption of the ring, by an interrupted transmission line or a disturbed car controller for example, guarantees the transmission of messages to each car controller in at least one of the two directions.Each car controller contains three remote serial link interfaces. The first remote serial link interfaces to the car fixtures; car buttons, car tell tale lights, etc. The second remote serial link interfaces to car related hall fixtures; hall position indicator hall lantern, etc. The third remote serial link interfaces to the group related hall fixtures; hall buttons, hall tell tale lights, etc.

Abstract: An apparatus for controlling an elevator door based on controlling an electric motor for driving the door with a microcomputer and resetting the microcomputer when the power supply fails has a voltage monitor which detects the power source voltage and a braking circuit forcibly brakes the motor if the power source voltage detected by the voltage monitor is lower than a prescribed voltage. The motor is forcibly braked when the detected power source voltage is between the prescribed voltage and the lower limit of the range of voltages at which the microcomputer can operate.

Abstract: A pulse encoder digitally derives a first value of speed at which the cage is moving at any given time. An analog device, such as a tachogenerator, derives the second value of the speed, in analog form, at which the cage is moving at the same time. The two speeds are compared in a comparator to determine the differences therebetween. If the difference exceeds a predetermined limit, an emergency stop is tripped to arrest the motion of the cage.

Abstract: A coaxial engine starter comprising an electric motor including a brush assembly, an output shaft with a pinion and slidable relative to the motor and a solenoid switch having a movable iron core for closing and opening switch contacts. A cylindrical member rearwardly extends from the rear end of the brush assembly of the motor to surround a contact operating space in which the switch contacts move and has a rear edge located close to a front end of the movable iron core to define a small clearance therebetween. A shield member is also disposed behind the movable contact and has an outer edge located close to the rear edge of the tubular member and defines a radially small clearance therebetween. Thus, the cylindrical member and the shield member substantially surround the contact operating space and they are in a telescopically movable relationship relative to each other.