GB514609A - Improvements in and relating to electric switches - Google Patents

Abstract

514,609. Air break switches. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 5, 1938, No. 3709. Void. Convention date, Feb. 6, 1937. [Class 38 (v)] An air-break switch, which may have a gas blast supplied from a tank in a truck 16 through fixed insulator 6 to the fixed contact 15 in hood 17, has an angularly-movable insulator 7 connected to the movable contact 5 through an operating mechanism allowing the contact 5 to travel faster than the insulator-head at least in the vicinity of the fixed contact. Contact 5 is arranged on a lever 3. which is pivoted at 11 to an arm 1 so as to form a kind of toggle, and is pivoted at 10 to a lever 2 pivoted at 12 to insulator 7. Also pivoted to 7 is a link 4 pivoted to arm 1, the latter pivot point and the position of point 10 together determining the relative speeds of 5 and 7, in the example shown, two to one. The arrangement also provides for a substantially straight-line movement of contact 15 particularly in the vicinity of the contact 15, and the arrangement of pivots 10, 11, and contact point 14 in a triangle prevents obstruction by ice. The effect of ice formations on the pivot can be reduced by making them small. Members 2, 4 may have a common pivot on insulator 7. In a modification, Fig. 2 (not shown), lever 2 is replaced by a member which is fixed to insulator 7 and is pins and slot connected at the end to lever 3.