GB427011A - Improvements in electric switches, suitable for use with overhead transmission lines - Google Patents

Abstract

427,011. High - tension switches. HENLEY'S TELEGRAPH WORKS CO., Ltd., W. T., 11, Holborn Viaduct, London, and BREEZE, H. W., 132, Wrotham Road, Gravesend, Kent. Oct. 14, 1933, No. 7678/35. Divided out of 426,968. [Class 38 (v)] In an outdoor switch for use with overhead transmission lines each movable contact comprises a blade 2 mounted loosely between two insulating bars 3 and passing through apertures in a box-like member 5 surrounding the bars 3 and held in position by a bolt 4 which passes through all of the members 2, 3 and 5. The blade 2 is loose on the bolt 4 and is loosely held by spring washers. In the switch shown in Fig. 1, four movable contact blades 2 are mounted between two bars 3 which are slidable in guides 8 bolted to longitudinal angle irons 11 joined at their ends by cross-bars 12 bolted to a pole 21. Corresponding pairs of fixed spring contact clips 1 are carried on insulators 9 bolted by means of U-bolts 13 to cross-bars 10 fixed to the angle irons 11. Clamps 16 are provided for connecting a lead wire from overhead wires to the contacts 1. The lower end of the bars 3 carries a rod 23 which is slidable inside a tube 24 having a slot 26 engageable with a pin 25 on the rod 23. A compression spring 29 is mounted between the tube 24 and rod 23 so that on pushing a handle 27 upwards the spring is strained until the lower end of slot 26 engages pin 25 to overcome the friction of the contacts, when the spring acts to give a quick break. The switch is held in the open position by the engagement of a notch (not shown) on the handle 27 with a bracket 28 under the influence of a pair of coil springs connected between the handle and the bracket. The movement of the bars 3 is limited by stops 30 engaging the guides 8. Specification 426,968 is referred to.