Abstract: A manually operated handle assembly for operating high voltage circuit interrupter devices which are suitable for circuit opening operations but which are not suitable for circuit closing operations. Interrupter devices for which the handle assembly embodied in the present invention is suitable, therefore, are intended to be used in conjunction with a disconnect switch that is suitable for circuit-closing operations. By removing a lock bar, which unless removed prevents movement of the operating handle, and raising the operating handle to the horizontal position, the operating handle can be pivoted to rotate an operating shaft which causes the interrupter device to trip open. Closing the interrupter device is accomplished by pivoting the operating handle farther and thereby rotating the operating shaft an additional amount.
Abstract: An operating mechanism for enclosed high-voltage switches is movable in tracks attached to the side of an enclosure. In a test position, the mechanism is uncoupled from the switches and moved away therefrom to permit it and its control circuits to be exercised without operating the switches. In a maintenance position, the operating mechanism is moved further away from the switches to provide access for conducting maintenance. A latch automatically secures the mechanism in the test and maintenance positions. A lever on the outside of the enclosure selectively releases the mechanism from the test or maintenance positions permitting it to be reinserted or withdrawn further, and also indicates when the mechanism is in the test or maintenance positions. Normally, the lever does not permit complete withdrawal of the mechanism from the enclosure. A stop pin must be removed to permit sufficient lever operation for such complete withdrawal.
Abstract: A bus-mountable, circuit-interrupting device, including an interrupting unit and a novel line-potential, manually-resettable operating mechanism for the unit, is usable in circuits in which faults may exceed the interrupting capability of the unit. A normally engaged pair of contacts in the unit is separable within an arc-extinguishing medium. The operating mechanism includes a robust, stored-energy operator, for separating the contacts, and a tripping mechanism, which selectively releases the stored operating energy. The tripping mechanism normally prevents release of the stored operating energy, and includes a high mechanical advantage lever-link system which permits a low latching force to counteract the stored operating energy. A ratchet-solenoid combination in the tripping mechanism selectively removes the low latching force.
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.
January 30, 1978
Date of Patent:
March 11, 1980
S & C Electric Company
Bruce A. Biller, Hiram S. Jackson, Henry W. Scherer
Abstract: An improved high-voltage fuse, the blown or unblown condition of which can be readily ascertained, is disclosed. Known fuses include a fusible element and a movable component, such as an arcing rod, which is held in a normal first position as long as the fusible element is present and remains intact. When the element fuses and arc is struck, the arcing rod moves through an arc-extinguishing medium to extinguish the arc, coming to rest in a second position. The fusible element, arcing rod, and arc-extinguishing medium are contained within an opaque, insulative housing for the fuse. In the improved fuse, the housing is made of an insulative material which is translucent. The housing's translucency is such that it may be difficult if not impossible to observe the condition of the fuse--blown or unblown--from the fuse's exterior. Accordingly, a member, mounted for movement with the arcing rod, is provided.
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: A bounce- and weld- resistant contact assembly includes a pair of spaced contact plates with facing contacts on their ends. A switch blade is rapidly movable into and out of engagement with the contacts. The contacts are convexities coined into the plates which add no mass to the plates. Thus, the natural frequency of the plates is maximized and the magnitude of oscillation of the plates, when the contacts are rapidly engaged by the blade, is minimized. Legs on leaf springs act against concavities formed in the plates opposite the convexities. The legs conformally nestle in the convexities so that their frictional engagement therewith and the spring force co-act to quickly damp the high frequency, low magnitude oscillations of the plates. The low mass coined contacts also permit close spacing of the plates to maximize magnetic forces thereon due to current flow therethrough. These forces aid the spring and the leg-concavity friction in quickly damping oscillations of the plates.
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.
Abstract: An end fitting for a high-voltage fuse is disclosed. A conductive end ferrule of the fuse has an enlargement formed near one end thereof, the enlargement having a shoulder remote from the fuse end which defines an exhaust port. The end fitting has a pair of arms with slots for selectively engaging or disengaging a fuse mounting and an externally threaded collar between the arms. The collar has an aperture with a shoulder on the wall thereof which engages the shoulder on the fuse so that the fuse end protrudes from the collar. The collar mates with an exhaust control device having a threaded bore therethrough. The bore contains a lip designed to engage the fuse end. When the fuse is inserted through the aperture in the collar so that the shoulders engage each other, the exhaust control device may be screwed onto the collar to trap the enlargement shoulder and the fuse end between the collar shoulder and the lip thereby mounting the arms to the fuse and closing the exhaust port with the exhaust control device.
Abstract: An improved end fitting for a high-voltage fuse is disclosed. The fuse is of the general type having a movable striker pin which resides in a first position as long as a fusible element of the fuse remains intact. Should the fusible element cease to be intact, through fusing thereof or mishandling of the fuse, the striker pin moves to a second position to partially exit beyond an end of the fuse when a sharp end of the striker pin pierces a seal at the fuse end. The improved end fitting is removably mountable to the fuse and includes a body having a bore therethrough. The first end of the body surrounds and encloses the seal. A rod, mounted for movement in the bore at the end of the body, resides in a first normal location when the striker pin is in the first normal position, and in a second location when the striker pin is in the second position.
Abstract: A mounting assembly for electrical switching elements oppositely mounts together the switching elements in a pair. Each switching element, which may be a high-voltage fuse, a disconnect blade, or the like, has a first and a second support point. A central support, which may be dihedral, mounts two insulators, the free ends of which extend away from each other. The free ends are attachable to the first support point on respective switching elements. A third insulator is mounted to the support opposite from the other two insulators so that a free end thereof is generally oppositely directed from the other insulators, producing a "Y" configuration. The end of the third insulator is attachable to the second support point on both switching elements. The assembly permits both compact, opposed mounting of a pair of switching elements, as well as one less insulator than used in typical mounting assemblies.
Abstract: An improved support assembly for a circuit-interrupting device is disclosed. The device is of a type having first and second end fittings which define a major axis and which are selectively engageable and disengageable from matching first and second mountings spaced apart in the assembly in insulated relation. The device can be manipulated by a hookstick selectively attachable to the first end fitting and held by a human operator, and so manipulated as to selectively engage and disengage the end fittings and their respective mountings and to open and close the device. The second mounting has a noncircular pin which can be slideably received in a slot in the second end fitting only when the second end fitting and the device are in one particular orientation. The slot contains an enlargement which permits the second end fitting to rotate in the second mounting once the pin enters the enlargement.
Abstract: A tamper-resistant enclosure for electrical equipment is disclosed. The enclosure includes a housing having generally upstanding and planar side walls which define a top opening. The top opening is closed by a generally horizontal and planar roof which is coextensive and congruent with the opening. Selected walls of the housing have formed at their upper edges a C-shaped structure, the open part of the C facing outwardly. The roof is formed to have a C-shaped structure around its periphery, the open part of the C facing inwardly. Facilities mount the roof to the housing so that the lower leg of the C on the roof is intermediate the legs of the C on the walls. Moreover, the upper leg of the C on the walls is intermediate the legs of the C on the roof. In this way, a labyrinth from the exterior of the enclosure to the interior is formed. Water entry through the labyrinth into the enclosure is prevented thereby, as is the insertion of wires or the like.