GB1026435A - Pressure relief means - Google Patents

Abstract

1,026,435. Valves. S. & C. ELECTRIC CO. May 11, 1964 [March 9, 1964], No. 19518/64. Heading F2V. [Also in Division H2] A pressure relief means suitable for use in circuit breakers comprises, in the embodiment shown in Fig. 2, a rupturable copper diaphragm 63 located at its outer periphery between a support ring 70 and an exhaust tube 61, the diaphragm being normally maintained in the position shown by means of strain wires 85 located between lugs 88 and a connecting member 89, and acting on the diaphragm via an adjusting plate 78, a ball 76, a jack screw 74 and a pressure plate 73. Secured to the diaphragm is a head 99 of a bolt 98, which bolt carries a diaphragm piercing means 93 and a piston 103. The outlet from the housing 53 is close d by a cover 108 held in place by a spring 111. The pressure within the housing acts via the diaphragm on the strain wires and on reaching a predetermined value causes the latter to break, thereby allowing the diaphragm to evert and also allowing the diaphragm piercing means to pierce the diaphragm, thus permitting the escape of gas, which escape results in a pressure difference across the piston, thereby causing it and the cutter to be ejected through the diaphragm and, along with the other separated parts, through the outlet of the housing 53. In the alternative embodiment shown in Fig. 9, excess pressure causes the diaphragm 41 to enter the recess 116 and this in turn causes the tube 123 to move, along with the disc 125. The movement of the disc fractures the strain-sensitive portion 131 of a bolt 133 and thereby releases a diaphragm cutter 136 which is urged to the right by a spring 137 to puncture the diaphragm.