Improvements in electric quick make-and-break switch mechanism

375,390. Tumbler switches. COOK, F. L., 42, Mollison Street, Abbotsford, Victoria, Australia. March 25, 1931, No. 9125. Convention date, April 17, 1930. [Class 38 (v).] An operating member 24 of a tumbler switch is made of moulded insulating material and is formed with depending arms 15 having integral offset pivot-pins 16 which are sprung into engagement with the upper ends of inverted U-shaped slots 17 formed in the moulded base 1. A thrust member 10 engages at one end with the reduced central portion of a contact roller 4 and at its other end carries a compression spring 11. and a conical cap 12 which engages a recess in the operating member. When the operating member is moved to the right the compression link is moved across the dead-centre and the contact 4 rolls along a curved track 8 to bridge contacts 3. Ridges 18 on the track 8 temporarily hold the contact to give a more rapid action. The operating member 24 is held in position by the spring 11 and also by ridges 25 under the arms 15.