GB480351A - Improvements in speed-responsive switches - Google Patents

Abstract

480,351. Centrifugal switches. BURGESS, A. F. (Lee Engineering Research Corporation) June 19, 1936, No. 17099. [Class 38 (v)] [Also in Group XIII] In a speed-responsive switch a rotary member 15 carries at its periphery a plurality of pairs of contact-carrying springs 28, 29 connected in parallel or series-parallel and adapted to disengage or engage each other simultaneously or in close succession at a certain speed. The position of the springs 28 is determined by screws 43 in a disc 40 rotatable with the member 15 but axially adjustable in relation thereto by means of a screw 46. The springs 29 with their contacts 33 are acted on by centrifugal force and at a certain speed leave the contacts 32 on the springs 28. In the' form shown there are ten pairs of springs 28, 29 and the current to them is led through brushes 25, 26 engaging slip rings. The springs 29 may be bimetallic so that if one of the contacts tends to overheat through arcing, the corresponding strip 29 bends and causes it to reengage its associated contact. This prevents overheating and tends to cause simultaneous operation of all the contacts. The spring 29 may be of steel and the plate 31, riveted to it, of brass or the substance known under the Registered Trade Mark " Duralumin."