Patent GB-413635-A (GB)
Title: Improvements in electrical relays for use in automatically reclosing circuit-breakersystems
IPC: H01H75/04
Filed: 1932-12-17
Abstract: 413,635. Protective cut-out systems. ELLIS, C. M., 14, Falcon Street, Roslyn, Dunedin, New Zealand. Dec. 17, 1932, No. 35871. [Class 38 (v).] Induction relays ; switches, actuating.-In an arrangement for automatically reclosing a circuit-breaker a given number of times, after which the mechanism is locked against further attempts if the breaker fails to stay in, a circuit closed by a single switch 32 comprised in a self-contained breaker 31 energizes a unidirectional motor 2 of the relay to control the reclosing motor 30b, and the relay has means for providing the time intervals for the given number of reclosing operation and for finally preventing closure of the breaker by its motor should the overload condition remain. The relay comprises an induction disc 2 and a core having parts 3-5, of which member 4 is energized by transformer action from member 3 to produce a rotating field, and member 5 is pivoted at 6 so as to be attracted to member 3 when it is energized, and retracted by a spring when de-energized. Member 5 also carries a fibre-shoe brake 7 for the disc and a copper band 7<a>, Fig. 2. The disc is mounted on a spindle 2<a> which drives a worm wheel 8 connected by a spring 13 with a pin 14 on a drum 10 on a shaft 9, the pin 14 taking in a larger hole in the wheel 8. Secured to the drum 10 is a disc 16 formed with notches 16<a>, 16<b>, 16<c> engaged by a spring pawl 15 which holds the drum 10 stationary until the lagging edge of the hole in the wheel 8 engages pin 14 and positively moves the drum, which is thereupon jerked forward by the tensioned spring 13. The drum has a contact strip 11 engageable with contacts 12, 12<a>, 12b, the latter to form a maintaining circuit for the relay after the breaker 31 has closed and consequently reopened contacts 32, for which purpose the contact 11 is made narrower at the point of engagement with the contact 12 of the reclosing motor 30b, Fig. 11. When the core 5 is attracted to core 3, an arm 28 on the spindle 6 is moved and engages as a check-pawl the teeth of a spring- returned wheel 18. At each complete turn of drum 10, corresponding to an attempt at reclosure, the arm 17 on shaft 9 engages and moves forward the wheel 18 one tooth. If the breaker remains closed after 11, 12 separate, the disc 2 continues to rotate until 11 disengages 12<a>, 12b, whereupon the relay stops, the arm 28 is retracted together with core 5, and 18 returns to its original position. If the breaker trips out, however, the relay goes on rotating, until, when the prescribed number of attempts have been made, a pin 18<a> on the wheel 18 engages and locks a segment 19 loosely pivoted on an arm 20. The arm 17 then engages the segment 19 and rotates the arm 20 against the action of a spring (not shown) interconnecting it and an arm 21. The latter is also freed from the arm 20 and rotates clockwise to move arm 24 from contacts 22 to contacts 23. Contacts 22 are in the circuit of the relay, which is thus cut out and the core 5 and wheel 18 released, and contacts 23 make the circuit of an alarm 35. To reset, a manual switch 29 shunting the contacts 22 is held closed long enough to enable the arm 17 to restore the parts 20, 21, 24 to the position of Fig. 3. An indicator 30 actuated by a pin on wheel 8, shows the number of reclosures, and the number is predetermined by adjusting the position of the back stop (not shown) of pin 18<a>.