GB189913646A - Improvements in Electrical Motive Power Apparatus. - Google Patents

Abstract

13,646. Hollick, T. D. July 1. Cranes; electrically-actuated apparatus.- Relates to means for stopping, starting, reversing, and varying the speed of electric motors used for driving cranes, hoisting- gear, and other machinery. The armature a and field magnets c are arranged so as to rotate in opposite directions, the field magnets being supported by a sleeve e on the armature spindle b. In the arrangement shown in Fig. 1, the sleeve e and spindle b are connected respectively to bevelwheels and k, gearing with a second pair of bevel-wheels l and m, free to rotate on studs carried by a frame or drum p, from which the power is taken, or which may itself form the hoisting-barrel of a crane. When current is supplied to the motor, the field magnets and armature rotate at the same speed in opposite directions, but the gearing is such that no motion is transmitted to the pulley p. If, however, the field magnets are stopped by applying a brake to the drum v, the armature drives the pulley p at half its own speed. Similarly, the armature may be stopped by a brake acting on a drum w, in which case motion in the opposite direction is derived from the field magnets. Intermediate speeds may be obtained by more or less retarding the motion of either part. Instead of bevel gearing, spur-wheels and pinions may be arranged so as to produce the same result. Two such arrangements are described for transmitting motion from the armature shaft to another shaft in line with it. In a modified arrangement, two motors are employed, the oppositelyrotating armatures of which are connected to the gear wheels and k respectively.