Patent GB-482448-A (GB)
Title: Improvements relating to electric winder equipment for mine hoists
IPC: B66B1/12
Filed: 1936-09-29
Abstract: 482,448. Regulating - apparatus for hoists. SMITH, G. D., GEORGE, H. N., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Sept. 29, 1936, No. 26451. [Class 78 (v)] [Also in Group XXXVII] A winder equipment for a mine hoist actuated by an electric motor is provided with control means whereby a winding operation may be initiated from a control switch, or from a plurality of independent control switches located either at the same or at different landing levels, and thereafter controlled automatically. Alternative control means whereby a winding operation may be manually controlled throughout is also provided, and selector means whereby the type of control employed may be determined. The Figure shows a winding induction motor WM having a contactor C in the supply leads and a liquid type resistance LC in the rotor circuit. The resistance LC is actuated by a hydraulic power cylinder MPC which also operates an automatic master controller AMC which controls the contactor C during automatic working. The cylinder MPC may be placed under the control of either a manual pilot valve MPV or of an automatically regulated pilot valve APV. The valve APV is operated by a torque motor TM current to which is supplied through contact h<1> by two generators BG and PG connected electrically in opposition so that the voltage applied to the torque motor is the difference between their voltages, The generator BG is driven from the winder so that its voltage will be proportional to the winder speed, and the generator PG is controlled by a rheostat PGR operated from a cam driven by the winder motor so that its voltage depends on the position of the cage in the wind. A twoway valve V determines whether the cylinder MPC shall be operated by the manual valve MPV or by the automatic valve APV, the valve V being connected to a selector switch S moving over three contacts MDA Closing of a switch ps at, say, the lower landing level, and a switch ks associated with the keps at the bank landing level closes contacts p, k to pass current through a coil H which closes contact h<1>. The value MPV is worked by the driver's lever DL, which is connected also to the rheostat PGR by a hydraulic link HL, and to a manual master controller MMC. The contact D of the selector switch S allows manual control without any supervisory limiting control, and the contact M gives manual control with an over-riding automatically-operated control determining the limiting speed at any particular point in the wind. The kep switch ks is replaced by two kep switches when control of movement in both directions, for the two cages, is required. The multiple switch then becomes effective only for a reverse operation, and a second multiple switch, with operating coil, is provided for forward winding. The brake solenoid is shown with an economy resistance which is shunted when the brakes are off and inserted when the brakes are applied, thus reducing the current necessary once the brakes are on. Limit switches are included to ensure that the circuit breaker can onlv be re-set if one of the cages is at bank, and provision is made, operated by the servo system, to ensure that the manual master controller is in the off position before the circuit breaker can be closed. Specifications 482,447, [Group XXXV], 482,449, and 485,088 are referred to.