Patent GB-686048-A (GB)
Title: Improvements in visual stroke signalling means for haulage plants
IPC: B66B19/06
Filed: 1950-10-26
Abstract: 686,048. Electric mine signalling systems. METRA, NARODNI PODNIK, and HRUBY, J. Oct. 26, 1950 [Oct. 28, 1949], No. 26095/50. Class 40 (i). In a mine hoist signalling system action signals registered visually in the engine-house are automatically cancelled (a) by the movement of the hoist brake lever operating a relay on the starting of the engine, (b) by the initiation of a " stop " signal or (c) by the action of a further relay on operation of the engine change speed lever. These relays have contacts in circuit with the drive-magnets of stepping switches controlling visual indication of the action signals in the enginehouse and hold the stepping switches in operative position corresponding to an action signal until occurrence of any one of the three conditions mentioned, when the stepping switches are advanced automatically to zero in readiness for a further action signal. As shown action (stroke) signals are initiated at the rock and coal loading level T by closing the switch TR a number of times corresponding to the order required. This rings the bells RZ at the men-loading level V, and RK at the level T, and actuates the drive magnet of the stepping switch SRT at the engine-house S so that the switch is stepped and operates one of the signal lamps NT corresponding to the number of strokes in the action signal. Subsequently, the final action signal is repeated by the operator at level V operating his switch TR. This rings the check bell RK at the level V and the stroke bell RZ in the engine house and at the same time advances the stepping switch SRV to operate the appropriate signal lamp NV. Both the operative NT and NV lamps now indicate the same action signal and the engineman acts accordingly. The action signal is cancelled immediately the engine brake lever is released by mechanical throwing of a switch SB which releases the relay RO to connect the drive magnets of the stepping switches SRT, SRV to an A.C. supply XY over their zeroizing contact segments whereby the switches are advanced to their zero position to cancel the visual signal. A " stop " signal may be initiated from either of the levels V, T, by closing the stop switch TS. This sounds warning horns HS at both these levels and in the engine-house and also energizes the winding Z of relay RP which causes zeroizing of the stepping switches and cancels the stroke signal as before. At the same time a relay IR is switched over by energization of its winding I to light the stop lamp NS in the engine-house. The stop signal is cancelled by the next action (stroke) signal from the level V when the first closure of the stroke switch TR reverses the relay IR to disconnect the stop lamp. Stroke signals are given to indicate both the engine speed required and the operation to be carried out. Upon receipt of the speed signal the engineman first operates his change speed lever (not shown) as required. This actuates a switch SP which momentarily energizes winding Y of relay RP to cancel the signal as before and zeroizes the. stepping switches. The new setting of the change speed lever is automatically confirmed by visual means at the levels T, V in a known manner (not shown) after which the operation to be carried out is signalled to the engineman by the appropriate stroke signal. Sticking of the relay RO in its "on " position after the engine has started operates the warning horns HS and the stop signal lamp NS to indicate the fault.