GB482915A - Improvements in electrical relay systems - Google Patents

Abstract

482,915. Electric relays. WESTON ELECTRICAL INSTRUMENT CORPORATION. Jan. 19, 1937, No. 1602. Convention date, Dec. 7, 1936. [Class 38 (v)] In a relay system of the type described in Specification 440,665 having an instrument-type relay with contacts which cause the energization of a motor, the motor actuates a switch for completing a holding circuit and pusher arms for separating the instrument contacts. The pointer 5 of an instrument with a moving-coil 4 carries a magnetic contact or rider 6 which when moved into the range of attraction of a relatively fixed magnet contact 7 or 7<1> is adapted to be attracted and held thereby. This completes the circuit of a small motor 16 such as a clock motor either directly or, as shown in Fig. 4 through contacts 29, 30 of a relay having a coil 27 supplied through a transformer 35 and rectifier 34. The relay also controls alarm or control devices 32a, 32b at contacts 30a, 30b in its released and operated positions respectively. The motor shaft 14<1> is connected by gearing 15<1> to a power shaft 15. At one end of the shaft 15 is mounted a " holding " switch in the motor circuit comprising a rotatable contact plate 21 with insulating gaps 22 at 90‹ intervals of its periphery. Brushes 23, 24 bear against the plate 21 the former being in continuous electrical contact therewith and the latter engaging the gapped portion near the edge. Thus when the motor is set in motion by the engagement of the instrument contacts an alternative circuit is at once completed by the brush 24 moving on to the surface of the plate 21 so that the motor circuit remains completed until a succeeding gap 22 comes opposite the brush. For separating the instrument contacts after their engagement a number of arms with turned-over ends are carried by the power shaft 15, the arms 18 moving the contact from the fixed contact 7 and the arms 19 engaging a bell-crank 20 to move the contact 6 from the contact 7<1>.