Abstract: A relay includes a movable contact piece having a first movable contact and a second movable contact, a first fixed terminal having a first fixed contact, a second fixed terminal having a second fixed contact, a drive device configured to move the movable contact piece, and the wall portion disposed inside the first fixed contact and the second fixed contact in a longitudinal direction. At least a part of the wall portion is disposed at a position beyond the first fixed contact and the second fixed contact toward the movable contact piece in a moving direction of the movable contact piece. The movable contact piece has a shape so as to avoid the wall portion in a contact state where the first movable contact is in contact with the first fixed contact and the second movable contact is in contact with the second fixed contact.

Abstract: A fuse incorporates a fusible element assembly and an auxiliary fusible element assembly in a solid arc extinguishing material configuration. The fusible element assembly has a first operating characteristic and the auxiliary fusible element has a second operating characteristic different than the first operating characteristic.

Abstract: A high voltage circuit interrupter characterized by a tubular insulating casing that encloses a tube of boric acid forming an elongated bore. The bore includes bore portions of smaller and larger diameter. An elongated conductor is disposed in the bore and forms a clearance space therewith. Fusible means extend between the enlarged conductor and a fuse terminal. Upon fusion of the fusible means the larger end portion of the conductor is retracted into the smaller bore portion while maintaining a clearance space therewith, so that a minimal clearance space between the smaller bore portion and the enlarged end portion of the conductor provides adequately high water vapor pressure to extinguish an electric arc generated by fusion of the fusible means.

Abstract: Disclosed is a mechanism for preventing the operation of a circuit interrupting device during the occurrence of excessive overcurrent. The circuit interrupting device includes an insulative housing having circuit-connectable opposed terminals thereon. Included within the housing is an arcing rod which is electrically connected to one terminal and which, in response to an overcurrent, moves away from a stationary contact electrically connected to the other terminal. Arcing rod movement elongates an arc formed between the arcing rod and the contact in an arc extinguishing environment to extinguish the arc and interrupt the circuit. The mechanism of the invention includes a shoulder on the arcing rod and one or more magnetic yokes positioned adjacent, but normally out of contact with, the shoulder. When an overcurrent through the device occurs which exceeds the device's rating, flux generated by current flow through the arcing rod moves the yoke to engage the shoulder thus preventing arcing rod movement.

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.

Abstract: An improved circuit interrupting device includes a pair of contacts which are relatively movable and between which an arc is established. Following melting of a fusible element, a stored energy source relatively moves the contacts apart to elongate the arc, and a container of pressurized dielectric fluid simultaneously directs fluid from a port at the arc. The fluid and the arc elongation ultimately extinguish the arc. A fusible diaphragm normally closes the port to prevent the escape of fluid, and also, due to its mechanical attachment to the contacts, restrains relative movement therebetween. The fusible element is so connected as to normally shunt current through the device away from the diaphragm. When the fusible element melts, all of the current through the device flows through and melts the diaphragm. As the diaphragm melts, two results are effected: fluid is permitted to escape from the port, and relative movement between the contacts occurs.

Abstract: A lead weight or other mass is crimped to the contact button assembly of the arcing rod of a high-voltage alternating-current power fuse thereby increasing the mass of the arcing rod without increasing the diameter of the rod. The increased mass of the arcing rod decreases the velocity with which the arcing rod moves upon fusing of the fusible member thereby decreasing the rate of elongation of the arc drawn between the end of the arcing rod and the stationary ferrule at the other end of the fuse. Under high current conditions, the shorter arc length drawn in the fuse reduces the pressure of the arc-extinguishing gas generated by the arc, thereby reducing the risk that an economically constructed fuse will burst in those situations when the arc is not interrupted at the first current zero. This result is accomplished without adversely affecting operation of the fuse and interruption of the arc at low current levels.

Abstract: An improved circuit interrupting device includes a pair of relatively movable contacts between which an arc is established. As the contacts are moved apart to elongate the arc, a container of pressurized dielectric fluid directs a flow of the fluid from a port at the arc. The fluid and arc elongation ultimately extinguish the arc. A diaphragm which normally closes the port to prevent fluid flow is normally mechanically attached to one of the contacts. When the contacts are moved apart, the container and the one contact also move apart tearing or cutting open the diaphragm to permit the fluid to flow at the arc. Both relative contact movement and the relative movement of the container and the one contact are effected by the action of the ignition products of a power cartridge on a piston-cylinder.

Abstract: This load-break fuse equipment comprises two draw-out fuse assemblies, one of the load-break type and one of the non-load-break type, each removably mounted in its own individual receptacle. The load-break fuse assembly and its receptacle comprise a load-break switch and a fuse electrically connected in series with each other. The non-load-break fuse assembly comprises a fuse, and this fuse is electrically connected in parallel with the fuse of the load-break fuse assembly and in series with said load-break switch.

Abstract: An improved circuit interrupting device extinguishes an arc by directing a dielectric fluid at the arc as it is elongated. Elongation is effected by relative movement apart of a pair of contacts between which the arc is established. A reservoir contains a piston which defines a first volume and a second volume. The fluid is held under pressure in the second volume. The reservoir directs the fluid in the second volume at the arc from a port normally closed by a diaphragm. One contact is normally mechanically attached to the diaphragm and is adjacent the other contact which is on the reservoir. Sudden expansion of the first volume, such as by the ignition of a power cartridge, forcefully moves the reservoir relative to the piston and away from the one contact. The seal is torn or cut open to permit the pressurized fluid to flow from the port simultaneously with the piston forcing the fluid from the second volume and the movement apart of the contacts.