Improvements in electric motor control apparatus, more particularly intended for application to electric steering gear for ships

摘要

359,635. Control of D.C. motors. SCOTT, W. H., Gothic Works, Norwich. Sept. 1, 1930, No. 26095. [Class 38 (iii).] Following movements of control member; non- regenerative braking.-In ships' steering gear of the kind described in Specification 226,638, [Class 38 (iii), Electric motor control systems &c.], in which the motor circuit is closed through one or other of two reversing contactors, means are provided for establishing a circuit across the motor armature and including hold-off coils for the contactors when both the contactors are open, the energizing circuit of each contactor being interrupted by the closure of the other contactor. When a wheel 16 is moved, contacts 26, 27, or 27, 28 are bridged by contact 24 or 25 to close the circuit of one or other of coils 13, 14 so that either a contactor 11 or a contactor 12 is closed to start the motor 1 operating in its proper direction. The motor drives the rudder quadrant 4 and also returns the contacts 24, 25 to their original position. When this is completed the closed contactor is opened, and with both the contactors 11, 12 open, a circuit is closed across the motor armature through a variable resistance 21 and through contactor hold-off coils 19, 20. The circuits of the closing coils of the contactors 11, 12 include auxiliary contacts 22, 23 on the contactors so that one contactor must open before the other can be closed. A resistance may be inserted in the armature circuit to function in sequence with the reversing contactors.