GB344020A - Improvements in electric switch mechanisms - Google Patents

Abstract

344,020. Snap-action switches. HENLEY'S TELEGRAPH WORKS CO., Ltd., W. T., 11, Holborn Viaduct, London, WHEELER, H. S. and MOOR, E., of Henley's Telegraph Works, Gravesend, Kent. Nov. 27, 1929, No. 36323. [Class 38 (v).] The operating mechanism, including a handle 1, a spring 4 connecting the handle to a crank 13, and a catch 16 for retaining the crank 13 until the spring has been sufficiently strained, is mounted as a unit outside the switch casing, the unit being readily detachable as by removing a split pin 25 from the contact-carrying spindle 9 and sliding the unit off the spindle. The spindle 9 is of square section and carries non-rotatably a sleeve 6 which is also partly of square section and carries non-rotatably the U-shaped crank 13 and another U-shaped crank 14 carrying the catch 16. The crank 14 has a rectangular aperture and can slide relatively to the sleeve 6 under the control of a spring 15. The catch 16 engages a fixed arc-shaped slot 20 in the casing, this slot having recesses at both ends into one or other of which the catch is normally pressed by the spring 15. The handle 1 rotates about cylindrical portions of the sleeve 6 and when it is rotated, the spring 4 is strained but the parts 13, 14, 6, 9 are held by the catch 16 until cam shaped slots 18, 19 in the handle lift the catch 16 out of its recess and effect a quick action. Should the spring 4 fail, the switch is positively actuated by the engagement of the ends of the cam slots in the handle with the catch 16. In a modification the sliding crank 14 is replaced by a relatively stationary crank carrying a slidable catch.