Movable storage unit system

Abstract

A movable storage unit system comprising a plurality of individually driven storage units at least some of which are movable toward and away from one another into contact with one another to define an access space between a pair of the units. A logic control circuit is provided on each unit and a limit sensor is provided on each movable unit including a sensor circuit for creating a signal in response to contact of a pair of storage units. A safety sensor is also provided on each unit and includes a safety sensor control circuit for creating a signal upon engagement of the safety sensor and an object or person in the path of the unit. A pair of reset controls is provided on each unit including a reset control circuit for creating a logic signal when actuated, and a run control is provided on each unit for creating a logic signal when actuated. The storage units are electrically connected such that a logic signal from the run control directs a run signal to a next adjacent unit. Each logic module includes a pair of reset transmit circuits for producing reset output signals, the reset transmit circuits of the logic modules being electrically interconnected. Each logic module includes a command inhibit circuit for receiving a run signal and electrically connected to receive signals from the reset control circuits, safety control circuit, and limit control circuit of its respective storage unit to inhibit the transmittal of the run signal. Each logic module includes a pair of move transmit circuits for producing move signals, the move transmit circuits of adjacent storage units being interconnected. Each logic module includes a move steering logic circuit for producing move command signals, the move command signal actuates a drive unit of a respective storage unit in one direction or the other.