GB254409A - Alternating current relay - Google Patents

Abstract

254,409. Howe, W. K. April 6, 1925. Induction relays for railway signalling have the slotted vane 34 forming the movable element carried by a pivot pin 33, the displacement of the vane being communicated to a pivoted contact-carrier bar 12 mounted on a pivot pin 11 parallel to the vane pivot 33, the vane and carrier bar being connected by means of a releasable coupling. This coupling comprises an eccentric roller 36 carried by the vane pivot which is engaged by the bifurcated end 20 of a depending arm 17 of the carrier bar 12. The bar 12 carries at each side sets of movable contacts 14 which co-operate with sets of fixed contacts 15, 16. The terminals 6 for the fixed and movable contacts are mounted on an upper insulating plate 3 forming the lid of the casing F, and the plate 3 carrying the whole of the contact mechanism may be detached without disturbing the vane and operating electromagnet E, the fork 20 leaving the roller 36 during this detachment. Similarly the pivoted vane and operating electromagnet are carried by a lower detachable plate 28 which may be removed without disturbing the contact mechanism. The casing F is fitted with glass side wall 1 for inspection purposes. The disc 34 is adapted to be moved in either direction from the normal position shown according to the manner in which the electromagnet E is energized, contacts being made in either of the displaced positions and if necessary also in the normal position. The movement of the disc 34 is limited by rollers 49 carried by pivot pins 48 sliding in slotted guides 47, the rollers thus acting as yieldable stops. The contact bar is held in its normal position as shown in Fig. 3 by weighted arms 23 pivoted at 24 and bearing adjustable screws 26 carried by a plate 25 secured to the contact carrier 12. When the carrier 12 is displaced in either direction the corresponding arm 23 is raised and returns the bar 12 on deenergization of the relay. The operating electromagnet comprises U-shaped cores 44 at opposite sides of the vane 34, each carrying a winding 45 and a third core 38 arranged transversely and carrying series-connected windings 40. In a modification, the third vane is omitted, one of the U-shaped cores being provided with an extra limb and pole piece. Adjustable balance weights may be provided on the vane spindle in this modification. Specification 166,879 is referred to.