Patent GB-1044618-A (GB)
Title: Spring operator motor charging means
IPC: H01H3/30
Filed: 1964-01-01
Abstract: 1,044,618. Automatic circuit-breakers; actuation of switches. I.T.E. CIRCUIT BREAKER CO. Jan. 1, 1964 [June 24, 1963], No. 110/64. Heading H2B. A load interrupter switch having main movable contact blades 105, Fig. 1, and an auxiliary blade (not shown) movable in an arcchute 108, comprises a spring operator 120, manual spring-charging means 150, motor spring-charging means 140 and a latch assembly 130. The spring operator 120, Fig. 2c comprises an overcentre spring toggle including concentric springs 208, 209 and a lever 213 mounted for rotation on a shaft 216. The lever 213 is turned to charge the springs by a sprocket 224 or by a member 219 which engages a pin 218 on the lever 213. As the spring toggle moves over-centre, the " knee " pivot 211 engages and moves a member 220 which is coupled to a driving member 116 on the switch operating shaft 114, Fig. 1. Resilient washers 229 cushion the impact at the ends of the spring movement and a spring-biased pivoted lever, Fig. 2a (not shown), restrains the spring 208 (but not the spring 209) during the latter part of the opening operation to reduce impact. When the switch blades are mounted with their pivots uppermost a pivoted latch member; Fig. 9a (not shown) co-operates with the member to prevent the blades closing under the force of gravity. The latch assembly 130, Fig. 5b, which may or may not be provided, comprises pivoted latches 506, 507 against which a roller 116f on the driving member 116 abuts when the springs 208, 209 have been stressed and the toggle has moved slightly over-centre both when the switch is to be opened or closed. These latches are moved to release the driving member 116 when a lever 517 is turned by an electromagnet 539, or manually by a Bowden cable 523, or by linkage 622, 626 operated by the striker pin of a fuse 162, Fig. 1. The motor spring-charging means 140, Figs. 3a, 3c comprises an electric motor having an output shaft 304 with a crank 307 actuating a reciprocating member 308 which carries a pawl 314 to step round a ratchet wheel 318 secured to a shaft 309 carrying a cam 319 and a crank. Initially the parts are in the position shown in Fig. 3a with the pawl 314 engaging a missing tooth portion of the ratchet wheel 318. To stress the springs 208, 209, a solenoid 320, as well as the motor, is energized to raise a link 329 so that a pin 331 turns the cam 319 and with it the wheel 318 so that the pawl 314 can engage the teeth of the wheel 318. When the springs are charged, a projection 319a of the cam moves the link 329 to engage a spring member 333 to open a micro-switch 330 and de-energize the motor and solenoid. Then the motor free-wheels continuing to turn the ratchet until the pawl 314 engages the missing tooth portion. The crank is connected to a link 343 having a pin 344 engaging in an elongated slot 221 in the member 219, Figs. 3c and 2c. Members 347, 348, which are moved by the toggle lever 213 deflect the pin 344 to the required end of the slot for the motor to turn the lever 213 in the appropriate switch-opening or switch-closing direction to charge the springs. The manual spring-charging means 150, Figs. 1 and 6e, comprises a handle 151 connected to a clutch plate 413 biased by a spring 411 away from a sprocket wheel assembly 407 which comprises a sprocket 409, a flanged portion for receiving the clutch plate 413 and a hub 408 carrying locking discs 450A . . . 450D. A chain 152 engages the sprocket 409 and the sprocket 224, Fig. 2c, of the spring operator. On manual operation, the handle is released from a spring catch 402 and pressed inwardly to cause a projecting portion of the clutch plate 413 to enter in a cut-away part of the flanged portion of the assembly 407. The handle is then turned to charge the springs. An indicator plate fixed to the periphery of the assembly 407 is visible through a magnifying glass 156 and indicates the various positions of the switch and mechanism whether operated manually or by the motor. Indicator lamps may also be provided in a control circuit. The locking discs 450A ... 450D have notches and may be placed to obtain a variety of locking positions when keys shown in Fig. 1 are operated to cause bolts (not shown) to enter the notches. The switch may be a single or a multi-pole switch and in the latter case the fuses in each pole operate a common linkage for releasing the latch assembly 130. When the switch is used as a circuit-breaker, after closing the switch, the springs are closed ready to open the switch but latched by the assembly 130 until released on the blowing of a fuse. The claims relate to the motor spring- charging means.