GB491114A - Improvements in or relating to electric contact making relays - Google Patents

Abstract

491,114. Magnetic relays. GREENLY, H. Aug. 4, 1937, No. 21492. Addition to 473,589. [Class 38 (v)] In an inductor relay of the type described in the parent Specification, having an armature with two parts 1, 2 pivoted at 4 and connected at 3 by a knuckle or like joint, the bearings 4 which may be steel ball bearings are magnetically screened from the magnetic field of the actuating magnet 9. This may be effected by means of two parallel bars or strips 8 of iron arranged as shown with the ends of the parts 1, 2 free of them so as to be influenced by the poles 9. In the form shown, the relay is operated by the deflection of magnetic flux caused by the passing of the wheel 12 of a locomotive or truck. The magnet 9 has a pair of double poles and a plate 11 of soft iron fits closely against the outer pair of poles to assist the dissipation of magnetic flux. When the attraction of the poles 9 for the armature weakens, its two parts are attracted downwards by a magnet 10 or by springs and contacts 5, 7 closed. The armature is mounted on a carriage 18 that is adjustably slidable and the magnet 10 is also adjustable. In a modification, Fig. 2 (not shown), the relay is operated by a magnetic member passing between the main part of a magnet and its poles which are separated from the main part by air gaps. The two parts 1, 2 may be of skeleton formation, each being formed of two thin iron plates welded or riveted together at the ends and embracing a pivot pin at their centre, Fig. 5 (not shown).