GB759986A - Electromagnetic contactor - Google Patents

Abstract

759,986. Electromagnetic switches. YALE & TOWNE MANUFACTURING CO. Oct. 7, 1954, No. 28896/54. Class 38(5) An armature 11 pivoted on an edge 15 on a bracket 13 and biased to the open position by a spring 20 acting between a lug 19 on a horizontal arm 18 of the bracket and an arm 16 of the armature extending through a bracket slot 17, carries a knife edge member 27 having edge parts 28, 29 co-operating with grooves 30, 31 in a contact arm 10, a centre part 32 of the member 27 extending through a slot 33 in the arm. A stud 34 on the armature extends freely through an opening 35 in the arm 10 and is surrounded by a spring 36 acting between the upper surface of the arm and a washer 37 on the end of the stud. When the contactor coil 12 is energized a contact 24 attached to the arm 10 engages a fixed contact 21, the spring 36 yielding upon contact engagement to permit further movement of the armature, Fig. 2, this further movement producing a wiping of the contact surfaces. The widely spaced bearing surfaces 30, 31 of the contact arm and the pressure of the spring 36 prevent a " cocking " movement of the arm when the contacts engage to accommodate any misalignment between the contact surfaces. Consequently, the contacts are caused to wear until they make good surface engagement, the wear then becoming very slow.