GB688027A - Improvements in or relating to cableways and like lifting and transporting systems having a hoisting mechanism on a carriage movable along a track or rope - Google Patents

Abstract

688,027. Electric control systems. ROPE & ROPEWAY DEVELOPMENTS, Ltd., BRITISH ROPEWAY ENGINEERING CO., L t d., SHIELDS, H. F. H., and PHILLIPS, W. K. V. No. 21244/49. Class 40 (i) [Also in Group XXX] A cableway, telpher or like lifting and transporting system (see Group XXX) is controlled by a radio receiver in response to signals from a remote radio transmitter. In the cableway hoist illustrated a continuously driven rope 12 passing around drums 13 on the carriage serves alternatively to traverse the carriage along its track 10 when the drums 13 are held by hydraulically operated brakes 35, 36 or to operate a hoisting drum 26 thereon through a differential gear and a variable ratio hydraulic coupling 20. The transmitter includes four audio-frequency tone generators arranged in pairs and controlled by interlocked switches so that the output of one tone generator of each pair may be applied to modulate the carrier. The receiver includes four relays each fed from the demodulator through a filter passing one of the modulation tones. Operation of either of the relays corresponding to one pair of modulation tones causes a motor 72 to run in a direction dependent upon which relay of the pair is operated. Operation of either of the remaining two relays energizes one of two solenoids 85, 87 to couple the motor 72, either to an arm 83 on a shaft 90 which controls the variable ratio hydraulic coupling 20, or to an arm 84 whose rotation controls valves 91 which operate the brakes 35, 36 on the drums 13. The couplings for the arms 83 and 84 comprise sprockets 77 and 78 driven through flexible couplings 75, 76 from the motor 72 and each raised by operation of the corresponding solenoid 85 or 87 to engage a chain 79 or 80 on an arcuate member 81 or 82 secured to the corresponding arm.. Thus for each operation the carrier must be modulated by two tones, one of which engages one of the couplings 77, 78 corresponding respectively to operation of the hoist drum and to traversing, and the other of which determines the direction of movement of the controlling arm 83 or 84. If the tone controlling the motor 72 is cut out, whichever coupling 77 or 78 is made holds the corresponding arm 83 or 84 in its 'displaced position; if however the tone controlling the coupling 77 or 78 is removed, the arm 83 or 84 is returned to its central position by springs. The interlocked switches at the transmitter for controlling the tone generators may be operated by a single control column working in a cruciform gate. A manually-operated switch is provided on the carriage to cut out the receiver which may also be cut out automatically in the absence of a carrier wave or when the driving rope 12 is at rest. The carrier wave may be modulated by coded pulses instead of by audio frequency tones.