GB1026868A - Improvements in or relating to electric moving coil relay arrangements - Google Patents

Abstract

1,026,868. Electromagnetic relays. SANGAMO WESTON Ltd. Nov. 28, 1962 [Jan. 12, 1962], No. 45041/62. Heading H2B. In a moving coil instrument type relay having contacts 21, 35 which complete the circuit of a second winding to increase the contact pressure, an initial increase in contact pressure is attained by the provision of a permanent magnet 31 and magnetic plate 32 which attract a magnetic member 20 on the movable assembly 10 only when the preset operating deflection is attained. The members 31, 32 are carried on a non-magnetic arm 24 co-pivotal with the assembly 10 and the setting can be adjusted by rotation of the arm 24 by a slotted link 27 engaging a pin 25 on the arm 24. When the member 20 passes behind the plate 32 (Fig. 3), the permanent magnet flux is diverted to the former and the contact 21 is urged against the spring contact 35. The aiding torque of the second winding moves the member 20 beyond the magnet 31 so that on de-energization of the coil both the magnet and the bias of the contact spring 35 tend to separate the contacts.