GB668381A - Improvements in motor speed governor - Google Patents

Abstract

668,381. Controllers; interrupters. HAYDON, A. W. Jan. 18, 1949. [Feb. 11, 1948] No. 1398/49. Classes 38 (iii) and 38 (v). [Also in Group XXXV] A speed governor for an electric motor comprises one or more pairs of spring loaded contacts interrupting the power supply to the motor, the contacts being released to close at regular intervals by an oscillating balance 'wheel, and being opened at intervals dependent upon motor speed by a cam driven by the motor. Contacts 17, 18, Fig. 1, mounted on spring arms, are in parallel with a resistance 20 in series with the motor 3. As shown, contact 17 has been moved outwards by lever 12 actuated by a cam 10 (driven by the motor) ; and contact 18 is being held in its outward position by a lever 34 which is held. by a permanent magnet 38 until a pin 33 on the balance wheel (30 rotating in the direction of arrow A) moves the lever away from the magnet. Contact 18 is released to close the contacts, the energy stored in the spring arm is transferred to the balance wheel, and lever 34 as it reaches its other extreme position is held by a magnet 42 and so holds contact 17 in the outward position. Contact 18 is then moved outwards by cam 10, the balance wheel reverses and releases contact 17 and so on. In a modification, Fig. 3 (not shown), the lever 34 is held in its two extreme positions by a bowed spring instead of by the magnets. In another modification, Fig. 5, the balance wheel lever 57 is held in its extreme positions by an integral bowed spring 58, and contacts 17, 18 are actuated by a cam 60. In a further modification, Fig. 7, a lever 65 actuated by the motor driven cam 75, is coupled to the balance wheel lever 34 by a coil spring 71. As shown, the supply circuit is open as contacts 63, 64 have just been opened by the cam 75. The balance wheel moves the contacts to the position shown in dashed lines, and the spring 71 then forces lever 65 down to again open contacts 63, 64, Fig. 8 (not shown), but since contacts 67, 70 are now closed, the supply circuit is completed and remains so until cam 75 again closes contacts 63, 64 and the cycle is repeated.