GB784799A - Improvements in cam operated electric switches - Google Patents

Abstract

784,799. Magnetic switches; switches held set and freed mechanically. COLNE SWITCHGEAR (K. & W.), Ltd., [formerly ELECTRICAL PRODUCTS (COLNE), Ltd.]. March 26, 1956 [March 24, 1955], No. 8550/55. Class 38 (5). A switch comprises a magnetic arm B pivoted at b and normally held in the position shown by a permanent magnet B<SP>2</SP> so that a contact d carried by a plate D engages a fixed contact c. The plate D is freely mounted on a pin d<SP>1</SP> upstanding from the arm B and is loaded by a spring d<SP>2</SP> whereby a wiping action takes place between the contacts. The arm B is moved to the closed position by a spring b<SP>3</SP> and to the open position by a cam E. The cam E cooperates with a roller D<SP>2</SP> carried by a lever D<SP>1</SP> pivoted at b<SP>2</SP> to the arm B, a spring d<SP>4</SP> biasing the lever so that a lever extension d<SP>3</SP> normally engages the arm. During an opening operation the spring d<SP>4</SP> is compressed until the lever D<SP>1</SP> engages a stop d<SP>6</SP> on the arm B whereupon the latter is forced off the magnet B<SP>2</SP> and the contacts separate under the action of the springs d4, d2. Arc screens A may be provided on each side of the contacts.