GB404861A - Improvements in or relating to electric circuit interrupters - Google Patents

Abstract

404,861. Arc-rupturing in switches. WESTINGHOUSE ELECTRIC AND MANUFACTURING CO., East Pittsburg, U.S.A.- (Assignees of Ellis, J. D.; 310, George Street, Turtle Creek, and Armstrong, G. C.; 33, Sumner Avenue, Wilkinsburg, both in Pennsylvania, U.S.A.) May 24, 1933, No. 14951. Convention date, May 25, 1932. [Class 38 (v).] Electromagnetic switches ; contacts.-The arc chute 31 of a switch is so mounted that it may be moved to expose the contacts 15, 16 and to prevent their closing. The chute is pivoted to the ends 41, 42 of a U-member 40 which is adjustably mounted by means of a screw 43 to an arm 22 to which is screwed at 44 the fixed contact 16. The movable contact 15 has a ridge-and-groove pivotal connection 21 with the carrier 17 mounted on the armature 12 of the operating magnet 11. A frusto-conical enclosure 23 houses a spring 20 serving to bias the contact 15 against its carrier and provide contact-pressure with 16. When the chute is rotated clockwise about 41, 42 to expose the contacts, a bridge 37 interconnecting the limbs of the chute engages a depression 45 in the contact 15 and by the arrangement of the pivots holds the contacts open against the weak attractive force on the armature, the latter force however being utilized for assisting to restore the chute to its operative position when the line of action of the closing force has passed below the pivots 41, 42. The chute pivots however may be arranged so that the force always tends to restore it to the operative position, but the contacts cannot be closed until they are adequately housed by the chute. The inner walls of the chute are ribbed to facilitate cooling and extinction of the arc, and are cut away at 34 to permit access to screw 44 when the chute is raised. In Fig. 5, the coil 11 is also de-energized by the displacement of the chute removing a spring blade 55 from normal contacting engagement with the arm 22. A modified pivot is also fitted, comprising a bracket 51 fastened by the screw 44 and having holes for bearing pins, as 52, on the chute. In another form, Fig. 7 (not shown), a sickle-shaped arm is urged by a spring into an obstructing position when the chute is raised, or even removed.