GB378567A - Improvements in or relating to braking devices particularly applicable to electric switches - Google Patents

Abstract

378,567. Electrically-tripped switches. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, TURNER, H. C. and ALDRED, L., of Salford Electrical Instruments, Silk Street, Salford, Lancashire. May 26, 1931, No. 15410. [Class 38 (v).] To absorb the momentum of the movable part of a circuit-breaker as it reaches the open position, a one-way brake is provided. The movable contact-carrier 6 carries a spring plate 2 and is linked to a lever 5 having a fixed pivot 17 and a rotary member 1 pivoted thereto at 19. Fig. 1 shows the braking action. In the closed position, the parts 1, 2 are separated, the part 1 hanging by gravity against a stop 18 on the lever 5. When the breaker opens, the arm 6 rotates counterclockwise about the pivot 7, carrying with it the plate 2; the lever 5 rotates clockwise to bring the part 1 into engagement with the approaching end 11 of the plate 2, which is accordingly bent backwards. The pressure between the parts 1, 2 as the former slides along the latter, produces the braking pressure which holds the part 1 against the stop 18, and the braking pressure is transmitted to the arm 6 both through the plate 2 and the lever 5. A stop 22 may be provided to engage positively the part 1 and arrest the parts. In the closing movement, the plate 2 rotates the member 1 clockwise so that the latter slides down the plate without producing a braking action. In Fig. 3 two members 1 are pivoted at 17 and spring-biased against a stop 18 so that, as the member 23 moves downwards to open, an equal braking force is produced by two spring plates 2. As the member 23 moves upwards in closing, the springs rotate the members 1 against the action of their springs 25 away from the stop 18 to remove the braking force.