GB641488A - Improvements relating to safety devices combined with electric signalling systems for mine hoists and the like - Google Patents

Abstract

641,488. Lifts. ALEXANDER, G. W., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Sept. 19, 1947, No. 25619. [Class 78 (iii)] [Also in Group XXXVIII] In a mine-signalling system combined with the hoist -motor-controlcircuits, the normal safety circuit including the brake lever contact BISI and control lever contact OP1 is shunted by circuits containing signal relay contacts, and the " man-rock " signal, and control-lever contacts, Fig. 3, whereby the driver cannot operate the hoist until the correct controladjustment and signal have been made. General-signalling.-The onsetter signals the driver over duplicate pushes SK1 at the man, and rock-loading levels (only one push SK1 shown in Fig. 1) and driver replies by push SK2. The onsetter also has " man-rock " signalling switches MR1 ... 3 at the respective levels operated by a detachable key and a switch MR4 operable only by the same key at the bank connected in parallel with SK1 for use at the first descent. The key can only be removed when a switch MR is in the " man " position. The driver and banksman exchange signals by pushes SK3, 4. Indicator lamp circuits are controlled by the signal relays, Fig. 2. Operation-hoisting men.-(Rock to men level). If after hoisting rock the onsetter wishes to hoist men, he changes the man-rock switch at his level, the other MR switches being necessarily in the man position to energize relay 35 and release 36 and signals his intention to ascend to main-level on bells EB1, EB2 with key SK1. Relay 31 is operated in parallel with the bells, and locks up, energizing 32. The driver has to move his " rock/man " control lever to the man position closing MSS1, 2 in the signal circuit before he can reply, and MSS5, 6 in the safety circuit. The driver's reply by SK2 de-energizes relays 31, 32. The onsetter then signals " hoist " by SK1, re-energizing relays 31, 32 and completing a circuit for timerelay 29 over 32d, and 34d which will be closed (assuming an all-clear signal has been received from the banksman over push SK4, thus energizing relays 33, 34). After a time delay sufficient to allow the onsetter to enter the cage, relay 29 operates completing the safety circuit at 29a. When the driver signals by SK2 that onsetter may leave cage at man level, relays 31, 32 are again de-energized, breaking the safety circuit. Hoisting men to bank.-The onsetter then loads men and signals " hoist by SK1 as above and men are wound to surface. The driver's signal to banksman by SK3 that men may leave cage, de-energizes relays 33, 34 and driver's signal to onsetter by SK2 that he may load men in the other cage opens the safety circuit until the " all-clear " is received from the banksman and the " hoist from the onsetter. Hoisting rock.-The onsetter is lowered to rock-level where he changes his " man-rock " switch to the rock position energizing relay 36. The driver has to change his " man/rock " control lever similarly, to complete the other branch of the safety circuit over MSS3, 4. Shoot interlock contacts WSB2, 3 prevent operation of the hoist during loading. Special-hoist-signals.-When long material has to be slung below the cage the driver may signal to the banksman by depressing SK3 and 5 together, one of the contacts DIS1, 2 being closed while a cage is between the bank and tip levels. A duplicate system for working with two onsetters and banksman is also described, Figs. 4, 5, 6 (not shown).