Improvements in or relating to electric switch fuses

摘要

1,080,072. Automatic circuit breakers; oil switches. J. G. STATTER Ltd. Feb. 6, 1964 [Jan. 7, 1963], No. 722/63. Heading H2B. The fuses 12 of a switch fuse are mounted in a carrier 11 slidable horizontally on a frame 17, 18 to break their circuits at contacts 5, 9; 6, 9 and thereafter pivotable about a shaft 19 to a position in which they can be inspected or replaced. The fuse carrier 11 is coupled by a linkage 28, 29 with a lid 3 of an oil tank 1 so that opening of the lid brings the fuses parallel to the upper face 2 of the housing. A projection 27 on the carrier 11 engages with a bracket 21 to prevent pivoting of the carrier while the contacts 5, 6, 9 are closed. To move the carrier 11 to its closed circuit position an arm 60 is first raised, pivoting a bell crank 39 about the shaft 19 to move rollers 38 to the end of slots 37, formed in a pair of sectors 33, where they are held by a latch 51 mounted on the sectors 33. This movement also oversets a toggle comprising one arm of the bell crank 39 and an arm 40 to compress a spring 42. Subsequent downward movement of arm 60 turns the sectors 33 with a snap action, moving the carrier through a linkage 34. Arm 60 is held down by a latch (54) (Fig. 9, not shown). Upon overload a fuse blows and detonates a small explosive charge to drive a pin 14 to release the latch 51. A spring 22 moves the carrier 11 forward and pivots the sectors 33 downwards. The latch 51 can alternatively be released by a push-button (97) (Fig. 10, not shown). After striking latch 51 pin 14 engages an arm (63) (Fig. 7, not shown) with the latch 51 so that contacts 5, 6, 9 cannot be reclosed until the fuse is replaced. The contact 5 can be earthed by a blade switch 68, operated by a handle 77, which through a link 79 is prevented from closing while the main contacts 5, 6, 9 are closed. A further safeguard is provided by a plate (84) (Fig. 5, not shown) pivoted to the front of the tank and shaped to prevent the levers 60, 77 both being moved to their closed positions. A door 24 covers the plate and is padlocked to prevent unauthorized alteration of the plate's position.