Patent GB-514217-A (GB)
Title: Improvements in or relating to electric circuit breakers suitable for high-voltage systems
IPC: H01H33/02
Filed: 1938-04-29
Abstract: 514,217. High-tension switches; actuation of switches. WESTINGHOUSE ELECTRIC & MANUFACTURING CO. April 29, 1938, No. 12848. Convention date, April 30, 1937. [Class 38 (v)] A circuit-breaker capable of controlling large amounts of power, comprises a substantiallytubular insulating casing containing the contacts, a switch-operating member movable to closed and open circuit position and mounted for movement within the casing in the direction of the longitudinal axis thereof, and actuating means for moving the operating member to open and closed circuit position. The actuating means comprise a driving lever pivotally supported adjacent one end thereof, and a linkage mechanism including a multiplying lever pivotally supported adjacent one end thereof, the free end of the driving lever being pivotally connected by a link to an intermediate part of the multiplying lever and a floating lever pivoted intermediate its ends to the free end of the multiplying lever, one end of the floating lever being pivotally connected to the switch-operating member. The arrangement is such that the travel and speed of operation of the operating member is multiplied over that of the driving lever, to which may be pivoted an insulating operating rod extending through the casing. Fig. 2 shows a single-pole structure mounted on a base 7 having rollers 9, two others being mounted behind that shown to provide a three-pole unit. Each of the two columns 11, 13 comprises sections 15, 17, 19, the upper containing the contactstructure, whereas the lower sections contain a current transformer 145 and potential transformer or voltage divider 147. Insulating liquid fills the lower sections and is separated from a similar body of liquid in the upper sections. A tie 139 connects the upper ends of the columns and contains a conductor for connecting the two contact-structures in series between line terminals 85. Tubes 21, 23 of fibrous material impregnated with synthetic resin, extend through the lower and upper sections, respectively, each of the tubes 23 supporting a ring member 25 which supports a cap member 71, to which is secured a moulded insulating sleeve 69 carrying the uppermost unit 33 of the contact-structure 31. As shown, the latter comprises a plurality of units 33 interconnected to form a number of series, simultaneous breaks between the fixed and movable contacts 39, 41, respectively, the latter being operated by a common reciprocable insulating rod 51 by means of levers 53 pivoted at 61 to a part 55 on the unit and at 57, 59 to the contact 41 and rod 51, respectively. The lower end of 51 carries a contact engageable with a further contact, which arrangement permits removal of the entire structure 31 from within the cylinder 23, the unit 33 being joined together at 49 for this purpose. Each unit 33 may have arc - extinguishing arrangement of the form disclosed in Specification 479,412 or 479,728. The rod 51 is urged upwards by a spring (not shown) and its upper end carries a contact 63 cooperating with an auxiliary contact movable by the operating mechanism, the arrangement being such that in opening circuit, the rod 51 follows up the mechanism to break the circuit in the units 33, whereupon the contact 65 moves on upward to introduce a further long break, whereas in closing, 65 first engages 63 and then drives rod 51 down to make the circuit in the units 33. The operating rod 137, Fig. 2, is connected to a pivoted T-lever linked at 135 to levers 129, to which operating rods 121 are connected. The latter are pivoted at 127 to driving levers 89 which are pivoted at 95 in the caps 71 and at 97 to links 101, which are pivoted in turn at 103 to a yoke-shaped multiplying lever 91 pivoted at 99 in the caps 71. Each limb of lever 91 is pivoted at 105 to a floating lever 93, the ends of which are pivoted to a yoke-shaped operating-member 35 carrying contact 65. Member 35 is vertically guided top and bottom by rollers 79 engaging between a pair of guides 75 riveted at 77 to sleeve 69. The limbs of lever 91 are offset at 113 for engagement by a pair of levers 111 which are pivoted at 99 and biassed by spring 115 to rotate 91 anti-clockwise, and the opposite sides of lever 91 carry projections 117 which engage the upper ends of levers 93 to move the toggles formed by the lower ends of levers 91, 93 over the line of centres 103, 109. When levers 89 are rotated anti-clockwise to open circuit, which may be effected by tipping a latch, the springs 115 cause lever 91 to rotate anti - clockwise, so breaking the toggle and causing levers 93 to move longitudinally and rotatably to bring the studs 120 into the slots 119 in the cap 71. During closing, when the levers 89 are rotated clockwise, the engagement of 120 in 119 restrains the free ends of levers 93 so that a considerable closing force is transmitted and rapid closure takes place, the final movement causing the toggle to be made, whereby a high contact-pressure is got.