GB901359A - Improvements in and relating to electrical signalling systems in hoisting apparatus (e.g. automatic winders, hoists and lifts) - Google Patents

Abstract

901,359. Mine cage-control apparatus. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Nov. 28, 1958 [Nov. 28, 1957], No. 38509/58. Class 78 (3). Relays P1, P2 (Fig. 1), controlling electric plant, are separately excited from an alternating current energized line L1, over a single conductor X1 and blocking rectifiers 1-4, by buttons A and C respectively. Discharge rectifiers 15, 16, or condensers (not shown), are provided to prevent spurious actuation of the other relay during the half-cycle periods when each relay is not being excited. The apparatus may be incorporated in a mine cage control system (Figs. 3a and 3b), in which contacts 1-13 are manually operated from the cage or mine levels, and are connected through blocking rectifiers and conductors X, Y, Z to remotely situated relays R 1-5 which respectively operate contacts S1-5 controlling the selective actuation of relays P1-13 which operate the cage driving motor and/or signalling lamps. In operation, movement of a control, associated for example with level 8, closes both contacts 8 thereby energizing relays R2 and R4. These, in turn, operate all the contacts S2 and S4 from the rest positions shown, thereby energizing relay P8 which locks over contacts Sp8 and a limit switch L8. The rest positions of contacts S1-5 and the grouping of contacts 1-13 are chosen to ensure that one relay P only is actuated for each actuation of a level control. The system has a further relay SC1 which must be operated over door closed contacts D1 and emergency stop button ES before the system can operate. In the case where the level controls are in the cage the conductors X, Y, Z may be either rigidly attached to the mine shaft, for co-operation with collectors on the cage, as incorporated in the winding cable, or another cable following movement of the cage.