Diaphragm having a pattern of reduced thickness in a high voltage, circuit-interrupting device

Abstract

An improved circuit-interrupting device of the type which includes an arcing rod which is moved away from a stationary contact in response to an overcurrent through the device. The device includes a container of pressurized dielectric fluid having a port from which the fluid is directed at an elongating arc formed between the moving arcing rod and the stationary contact. The device also includes a diaphragm normally contacted by the arcing rod which normally closes the port and restrains arcing rod movement. The improvement includes a pattern of reduced thickness in the diaphragm about the point of contact between the diaphragm and the arcing rod. The pattern may be circular or star-shaped and may be produced by pressing, dieing, stamping, scoring, forming, etching, or coating. Depending on the specific construction of the device, the diaphragm either fuses or melts along the pattern or is ruptured or torn by arcing rod movement following an overcurrent through the device. The pattern ensures that a large opening is formed in the diaphragm to permit the escape from the container of sufficient dielectric fluid to ensure extinguishment of the arc.

Dependencies are inferred from the claim text.