GB1205396A - Mine shaft winding apparatus - Google Patents

Abstract

1,205,396. Winding apparatus. COAL INDUSTRY (PATENTS) Ltd. 15 Dec., 1967 [19 Dec., 1966], No. 56676/66. Heading B8B. A control system in a colliery shaft winding apparatus for preventing an accumulation of slack cable above a halted cage comprises a unit 1 for producing a first output signal 2 related to the amount of cable displaced by a winding drum, a detection device 6 for producing a second output signal 7 related to the extent of movement of a cage attached to the cable, and a means responsive to the first and second outputs which produces a control output when displacement of the cable exceeds the extent of movement of the cage by a predetermined maximum excess of movement, which control output prevents further displacement of the cable. The unit 1 comprises a pair of solid state detectors associated with a plate rotatable in proportion to the cable drum, and capable of generating the pulsating output 2 representing movement of the cable and passing directly to a pulse counter 4, and a pulsating output 3 which indicates the direction of rotation of the cable drum and which passes to a counter control circuit 5. The cage detection device 6 which is provided in the delivery/loading station area of the shaft, comprises a reed switch commutator unit driven by a spring-loaded wheel engageable by a skid on the cage in the detection area, a pulsating output 7 from the detector 6 passing to the counter control circuit 5. In operation, upon rotation of the drum, pulses of the output 2 feed the counter 4 until a predetermined number, indicative of a predetermined cable length, cause the counter to trip, which produces a signal to stop further rotation of the drum. The counter trip can only be cleared if the drum is rotated in the opposite direction to wind up the cable. The pulses of signal 2 are added or subtracted at the counter 4 depending on whether the pulses of signal 3 represent the paying out or winding in direction of the drum respectively. The pulses of output 7 from the cage detector 6 cause the count in the counter 4 to be reduced to zero or by unity per pulse such that pulses from the unit 1 are balanced out provided the cage is moving whilst in the detection zone. Once the cage leaves this zone a cut-off device prevents the counter from tripping. An indication of slip either between the cable and the drum or between the cage and the detector unit is achieved by comparing the occurrences of the output pulses 2 and the output pulses 7.