GB221036A - Improvements in and relating to electric switches - Google Patents

Abstract

221,036. Backus, J. June 23, 1923. Switches, quick-action; contacts; sparking- preventing.-A switch of the rotary barrel type has a contact carrying member formed of a plurality of discs or blocks of non-conducting material, each having a channel or channels formed therein and running transversely thereof, and disposed so as to cut the axis of the body, or on each side of the axis, a spring-pressed member or members disposed in the channels, and an arc-shaped contact pivoted at the outer end of the member or members. As shown in Figs. 1 and 3, the base 1 has a peripheral flange 1<a> and central opening 2 through which the movable part of the switch can be passed. Non-conducting blocks 4, clamped together by screws 4<a>, have parallel recesses 7 within which are U-shaped bodies 8 pivoted by means of pins 11 to arcshaped contact plates 13. Springs 14 are disposed between the limbs of the bodies 8 and bear at one end on the contacts 13 and at the other on plates 10 extending between the limbs inside the inner ends thereof, the springs 14 tending to urge the bodies 8 outwardly. The fixed contacts 15, having lead-attaching screws 15<a> have recesses on either side engaged by non- conducting blocks 16 also recessed to receive screwed rods 18 passing through a plate 19, the base 1, ani a closure 20 for the opening in the base. A handle is attached to a spindle 19<a> and a second spindle 6<a> is provided. In the modification shown in Figs. 4 and 8, a single body 8 is provided in each block 4, but the contacts are carried by the arms of a spider 23, bent at 24 for securing to the base, and comprise plates 25 insulatingly clamped thereto by nuts 28 and screwed studs 26, one of which may be extended to form a terminal. A spark break 30 is provided and is in the form of a spring- controlled radially-disposed insulating plate which is moved aside by the fixed contacts and springs back again to intercept the arc. To give a quick action, the spindle 19<a> carries an arm 31 and the spider 23, or plate 19, has pivoted thereto an arm slotted at 33 to engage a pin 34 slidable therein and carrying a roller 35 under the action of a spring 36. The travel of the roller 35 is limited by projections 37, 38 .on the arm.