GB905551A - Improvements relating to trackless conveyors - Google Patents

Abstract

905,551. Automatic steering-control systems. ELECTRIC & MUSICAL INDUSTRIES Ltd. Nov. 21, 1958 [Nov. 21, 1957], No. 36297/57. Class 38 (4). [Also in Group XL (c)] In a system in which means responsive to the magnetic field of a conductor carrying current controls the steering of a vehicle to cause it to follow the course of the conductor automatically, the current is modulated to control the vehicle otherwise than by steering. In Fig. 1, coils 2 and 3 are mounted on a moving vehicle (not shown), so that when they are not symmetrical relative to a cable 1, carrying R.F. current and lying on or beneath the ground, a difference signal derived from a unit 9 operates a steering motor 10 in the appropriate direction to restore the vehicle to a symmetrical position relative to the cable during its travel. Coils 2 and 3 are mounted on an arm which swings with the front wheels of the vehicle to increase sensitivity. Should the vehicle wander off course sufficiently, the sum of the signals from coils 2 and 3 derived from a unit 11 is unsufficient to maintain operation of a relay RL1 so that the vehicle is stopped by disconnecting its driving motor 14 from battery 13. A brake (not shown), may also be applied simultaneously. Where a number of vehicles is involved, each may respond to a different frequency so that different routes are followed. Sections of the cable common to more than one route are energized at several frequencies by setting up plug-boards associated with each frequency. The supplies may be pulse modulated to operate relays or selector switches on the vehicles to remotely stop, load or unload them.