GB104733A - Improvements in Stationary Contacts for Electric Switches or Circuit Breakers. - Google Patents

Abstract

104,733. Holt, F. B. March 15, 1916. Contacts.-Fixed contacts for electric switches and circuit-breakers are made of metal strips which are bent to form limbs passing through a single opening in the switch base or support, the limbs being secured together by clamps provided with tightening-bolts disposed in a direction perpendicular to the limbs. As shown in Fig. 2, the limbs 10 of contacts 5 pass through an insulating- sleeve 12, which is sufficiently elastic to permit of the clamping of the limbs by U-shaped members 13, 14 and transverse bolts 15, the members 13, 14 being secured by bolts 19 to the switch base 11. Roughened metal plates 18 may be arranged between the limbs, and the insulating-sleeve may be omitted. In the form shown in Figs. 5 and 6, a rigid sleeve 23 with a cylindrical bore is used, and the limbs of the ccntacts 20, 21, 22 are bent to lie alongside one another. Below the sleeve, the limbs are secured by knife-edged plates 32 upon the two U-shaped members 80, 31 of a clamp provided with transverse bolts 34, and above the sleeve the limbs pass through a washer 26, a spring washer 37, and a clamp 28, 29 connected to the lower clamp by bolts 38, 39. To prevent the contact from turning relatively to the sleeve, the lower clamp members have pins 35 engaging with a transverse recess 36 in the lower end of the sleeve. Roughened metal plates may be fitted between the limbs, or strips of paper may be used. The contacts may be provided with auxiliary contacts, and when designed for oil switches, the insulating-sleeve 12, Fig. 2, may dip below the oil surface. When the contacts are to be used with alternating currents, the limbs of the strips may be interlaced to avoid losses due to skin effect. Specifications 28746/13 and 3001/15 are referred to.