Abstract: An apparatus and method for determining one or more operating characteristics of a vehicle mounted to and movable on a rail. A magnetic strip is mounted to the rail, and is provided with alternating regions of flux and no-flux. The vehicle is provided with a magnetic sensor, which senses the alternating flux regions of the magnetic strip as the vehicle move on the rail and outputs a signal in response thereto. The signals output by the sensor are processed by a micro-controller, to determine the vehicle speed, location and/or displacement from a predetermined point. The system is advantageously employed in any number of applications, such as in factory automation systems, automated material storage and retrieval systems, overhead crane control systems or the like.

Abstract: An adjustable frequency motor drive system for a hoist is disclosed in which the frequency of the power supply to the motor can be selectively varied and the speed of the motor will follow the varying frequency at a slip speed relative to the frequency. The slip speed of the motor may not exceed a value beyond which the motor can control the hoist load. Accordingly, a frequency value based on the frequency of the power supply to the motor is selected as the frequency which is not to be exceeded by the motor speed expressed as a frequency. Signals representative of the actual motor speed and the selected frequency value are compared and, if the signal representative of the motor speed exceeds the signal representative of the frequency value which is not to be exceeded, an output signal is produced which may be used to apply a brake which stops and holds the motor and hoist and thereby maintains the load suspended.

Abstract: An elevated track network guides self-propelled guided vehicles (with containers thereon) from an entry location where objects enter the system, to a storage zone defined by sets of compartmentalized storage racks wherein containers filled with objects are temporarily stored, and from thence to an exit location where retrieved objects leave the system. Each set of storage racks comprise four racks and two aisles, with two of the racks arranged back-to-back between the aisles and the other two racks on opposite sides of the aisles. Each storage rack comprises storage compartments arranged in horizontal rows and vertical columns. A track in the track network extends through and along an intermediate row in one of the back-to-back racks (pre-empting the compartments in that row). Each aisle accommodates a self-propelled aisle crane which services the racks on both sides of the aisle.

Abstract: The storage and retrieval apparatus of this invention comprises parallel tracks, each normally supporting numerous upright storage bins that are in close proximity to one another and to bins on laterally adjacent tracks. Each bin is open at its front and is mounted on wheels to roll rearward along its track. An overhead carrier lifts a desired bin off its track to a level above the other bins and carries it forward. A pusher near the front end of that track pushes rearward on the front bin, moving bins back to fill the space left by the lifted bin, which is then lowered into the space at the front of the track for loading or unloading, through its open front. On the top of each bin is an identifier plate distinctive to the bin. A sensor on the overhead carrier, connected with a computer, reads the identifier plates as the carriage moves rearward along a track and is thus able to find and lift a desired bin even though it is in a random position along the track.