GB231676A - Improvements in or relating to electromagnetic relays - Google Patents

Abstract

231,676. Richter, M. B. April 16, 1924. Relays, contact-making. - The magnetic circuit of an electromagnetic relay comprises an iron core for the energizing coil, an L-shaped yoke connected to one end of the core and projecting over the other end, and an armature pivoted on the projecting end of the yoke to turn about an axis parallel to the core, one of its arms cooperating with the end of the core and the other arm with the contact springs. Figs. 1 and 3 show a double or step-by-step relay in which two such units are structurally united while maintaining their magnetic circuits independent. The vertical portion of each yoke. 1 is formed with a slot in which the core 4 is secured, and the horizontal portion is formed with an obliquely-cut slot 5 parallel to the axis of the core. The armature 6 passes through the slot 5 'and is provided with knife edges 8 bearing on the upper surface of the yoke Its upper arm 9 is staggered as shown in Fig. 3 and its lower portion is formed with a hole through which extends a non- magnetic bolt 11 secured to the core 4 and provided with a head 12 constituting a stop. To prevent sticking the armature carries small stops or the core is provided with a thin non- magnetic covering. In the double relay the vertical portions of the two yokes are secured to a brass plate 13, and the other ends of the yokes are connected by a similar plate 14 provided with slots through which the cores 4 extend. An oval hole 31 is provided in the plate 14 to admit an expanding tool for pressing the edges of the slots against the cores. The contacts are carried by springs supported from turned-up portions 2, Fig. 1, of the yokes, and in the double relay shown those on the left are opened and those on the right are closed by the operation of the corresponding armatures. The left-hand armature 6 bears on an insulator 28 carried by the spring 20 and passing freely through the springs 19 and 21, and the spring 19 carries an insulator 29 bearing against the armature and thus acts to return the armature to normal position, Fig. 3. The right-hand armature 6 bears on an insulator 27 carried by the spring 25 and passing freely through the spring 24, and the springs 22 and 24 carry respectively insulators 30 and 35, Fig. 10, bearing against the armature, and thus act like the sprring 19 to return the armature to normal position. For ensuring sensitiveness. however, the insulators 30, 35 are arranged to be slightly removed from the armature when the latter is fully operated.