Abstract: A vacuum circuit interrupter includes a line conductor, a vacuum interrupter, a load conductor, a ground conductor and an operating mechanism. The vacuum interrupter includes a fixed conductor and a vacuum envelope containing a fixed contact and a movable contact movable between a closed circuit position in electrical connection with the fixed contact and an open circuit position spaced apart from the fixed contact. The fixed conductor is outside of the vacuum envelope and is electrically connected to the fixed contact. The load conductor is electrically connected to the movable contact. The operating mechanism is structured to: open and close the fixed and movable contacts, and move the vacuum interrupter and the fixed conductor thereof between a first position wherein the fixed conductor is electrically connected to the line conductor, and a second position wherein the fixed conductor is electrically connected to the ground conductor.

Abstract: A vacuum arc interrupter that includes a vacuum chamber assembly and a pressure chamber assembly. The vacuum chamber assembly includes a vacuum chamber and a first conductor which is structured to be coupled to a circuit. The first conductor is disposed within the vacuum chamber. The pressure chamber assembly has a second conductor structured to be coupled to a ground, a pressure chamber, a gas generation device and a bullet assembly. The pressure chamber assembly disposed adjacent to the vacuum chamber assembly. The gas generation device coupled to, and in fluid communication with the pressure chamber. The bullet assembly is disposed in the pressure chamber and structured to move between a first position, where the bullet assembly is spaced from the first and second conductors, and a second position, where the bullet assembly contacts, and is in electrical communication with, the first and second conductors.

Abstract: A vacuum arc interrupter that includes a vacuum chamber assembly and a pressure chamber assembly. The vacuum chamber assembly has a first conductor coupled to a power line, a non-conductive housing and a seal cup. The pressure chamber assembly has a second conductor coupled to a ground, a pressure chamber and a bullet assembly. The pressure chamber assembly is disposed adjacent to the vacuum chamber assembly. The bullet assembly is disposed in the pressure chamber and is structured to move between a first position and a second position. The bullet assembly has a metal lance with a blade portion. The blade portion is structured to puncture the seal cup.

Abstract: A vacuum arc interrupter that includes a vacuum chamber assembly and a pressure chamber assembly. The vacuum chamber assembly has a first conductor coupled to a power line, a non-conductive housing and a seal cup. The pressure chamber assembly has a second conductor coupled to a ground, a pressure chamber and a bullet assembly. The pressure chamber assembly is disposed adjacent to the vacuum chamber assembly. The bullet assembly is disposed in the pressure chamber and is structured to move between a first position and a second position. The bullet assembly has a metal lance with a blade portion. The blade portion is structured to puncture the seal cup.

Abstract: A vacuum arc interrupter that includes a vacuum chamber assembly and a pressure chamber assembly. The vacuum chamber assembly includes a vacuum chamber and a first conductor which is structured to be coupled to a circuit. The first conductor is disposed within the vacuum chamber. The pressure chamber assembly has a second conductor structured to be coupled to a ground, a pressure chamber, a gas generation device and a bullet assembly. The pressure chamber assembly disposed adjacent to the vacuum chamber assembly. The gas generation device coupled to, and in fluid communication with the pressure chamber. The bullet assembly is disposed in the pressure chamber and structured to move between a first position, where the bullet assembly is spaced from the first and second conductors, and a second position, where the bullet assembly contacts, and is in electrical communication with, the first and second conductors.

Abstract: A new class of low chop contact materials based on Ag-chromium carbide and Ag--Cr compositions have an essentially 100% dense, porosity free microstructure. These materials combine the advantageous properties of Ag--WC and Cu--Cr contacts without their disadvantages. A method of making this new class of low chop contact materials includes the steps of cold pressing a mixture of Ag and chromium or chromium carbide to form an unsintered blank and the elevated temperature infiltration of silver into the unsintered blank to obtain an essentially 100% dense, porosity free microstructure.

Abstract: An axial magnetic field vacuum interrupter includes a field producing structure associated with only one of two opposing electrode assemblies. The field producing structure is characterized in that when the instantaneous peak arc current is I.sub.m, measured in kiloamperes, and the electrode assemblies are in the open circuit position, the instantaneous component of the axial magnetic filed (AMF) B in the axial direction B.sub.a, measured in milliteslas, imposed on the majority of each electrode contact surface is given by the analytical expression.

Abstract: A new class of low chop contact materials based on Ag-chromium carbide and Ag-Cr compositions have an essentially 100% dense, porosity free microstructure. These materials combine the advantageous properties of Ag-WC and Cu-Cr contacts without their disadvantages. A method of making this new class of low chop contact materials includes the steps of cold pressing a mixture of Ag and chromium or chromium carbide to form an unsintered blank and the elevated temperature infiltration of silver into the unsintered blank to obtain an essentially 100% dense, porosity free microstructure.

Abstract: A multiple electrode structure for a vacuum interrupter that encourages formation of a diffuse arc includes a pair of disk-shaped, confronting electrical contacts that are relatively movable between a closed circuit position and an open circuit position and that are enclosed by a vacuum envelope. Each contact has generally spiral-shaped arms defining slots therebetween. The slots gradually widen towards the periphery of the contacts. In addition, the contacts are rotated relative to each other such that the tip of each spiral arm of one contact faces a generally radially extending portion of a spiral arm of the other contact. A generally tubular metal vapor shield surrounds the contacts within the envelope and is electrically isolated from at least one of the contacts in the open circuit position. The design and orientation of the contacts increases the radial component of the self-induced magnetic fields generated by the current in the interrupter.

Abstract: A vacuum interrupter with an enhanced radial magnetic field includes within a vacuum envelope a pair of confronting contacts that are relatively movable between an open circuit and a closed circuit position. The contacts, which can be the spiral-arm type or the slotted-cup type, are surrounded by a tubular metal vapor shield that is electrically isolated from at least one of the contacts in the open circuit position. Each contact is connected in series with a coil energized by the current in the interrupter and positioned proximate the non-confronting face of the contact, and with a current carrying terminal post extending outside the vacuum envelope. The current in the coils produces a radial magnetic field in the intercontact region that encourages a columnar arc between the contacts to move outward and attach to the vapor shield. This helps to promote a transition to a diffuse type of arc and allows for a more compact interrupter with greater interruption capability.

Abstract: An electrical vacuum interrupter comprising a pair of separable contacts enclosed within a vacuum enclosure whose walls have joints formed of a polymeric material which can maintain sufficient vacuum, mechanical, thermal, and electrical properties to permit proper operation. Major part of the vacuum enclosure, in addition to the joint, may be formed of a polymeric material. A method of assembly is provided that avoids need for high temperatures and includes use of electrical discharge between the contacts for cleaning the interior of the vacuum enclosure.

Abstract: A vacuum interrupter characterized by an all-ceramic envelope forming an evacuated chamber in which a pair of separable contacts are disposed. The envelope is comprised of two substantially half portions having abutting end surfaces that are secured together in a vacuum-tight manner.

Abstract: An axial magnetic field vacuum-type circuit interrupter. Provided in an evacuated housing is a pair of opposed contacts at least one of which is movable with respect to the other and is movable between a closed position in engagement with the other contact to an open position spaced apart from the other contact to form an arcing gap therebetween during circuit interruption. Each contact includes a disc-shaped backing plate having at least two radially spiraling slots therethrough and a contact and arcing ring secured to and positioned about the face of the backing plate. The backing plates are substantially parallel to one another with the direction of the spiraling slots therethrough being reversed with respect to those of the opposing contact. Because of the reversed direction of spiraling in the opposed faces of the backing plates, an axial magnetic field is created by the flow of current through the contact structure which causes the arc to remain diffuse during the circuit interruption.

Abstract: The invention provides a technique for interrupting current employing a plurality of series connected vacuum arcs in parallel with a resonating circuit. At least one of the series vacuum arcs is subjected to an oscillating transverse magnetic field which produces modulations in the arc voltage. The arc voltage modulations initiate oscillations in the parallel resonating circuit, producing current modulations in the series connected vacuum arcs. The current modulations rapidly extinguish the arcs, interrupting the current. Use of a plurality of series connected vacuum arcs improves the recovery voltage hold-off potential of the circuit.

Abstract: An improved envelope for a vacuum device circuit interrupter of the type having a pair of relatively movable electrodes within a vacuum envelope and including magnetic field arc suppression. The envelope includes end portions which support the electrodes and an intermediate insulating portion which surrounds and is spaced from the electrodes. Means for producing a magnetic field is outside the envelope. The insulating portion is of a shape which provides a greater distance between the electrodes and the surrounding insulating portion in the direction in which an interelectrode arc is deflected by the magnetic field. In the preferred embodiment the insulating portion is substantially cylindrical in shape with a pair of protruding side tubes. The interrupter envelope is oriented so the arc is deflected down the inside of the side tubes.

Abstract: A vacuum arc current interruption device is installed in a current limiting circuit which includes a parallel resonant circuit. Means are provided for producing transverse lines of magnetic force in the arc gap between the electrodes in the vacuum enclosure. The energizing circuit for the magnetic field coils includes a capacitor bank employing unpolarized capacitors and a switch. After the capacitor bank is charged up, the switch is closed, discharging the capacitors through the field coils and producing lines of magnetic force in the arc gap. The field coils and capacitor bank together form a resonant field circuit having a characteristic resonant frequency which causes periodic reversals in the polarity of the lines of magnetic force. The oscillating magnetic field produces responsive oscillations in the arc voltage of an arc present in the arc gap of the vacuum device, which in turn causes oscillations of the arc current.

Abstract: A vacuum arc current switching device employs a shielding arrangement including a plurality of coaxially disposed cylindrical non-conducting members for minimizing exposure of the interior wall surfaces of the enclosure to vapor deposition of cathode material so as to prevent the formation of secondary arc terminals on the interior surfaces of the enclosure. The shielding being non-conducting prevents secondary arc formation which would otherwise permit arcing from the cathode to the shield and then back to the anode. The shielding further comprises annular transverse members disposed at the ends of the enclosure so as to protect the end wall surfaces as well.

Abstract: An electrical contact suitable for use in high-current switching or circuit breaking, comprising a mixture of silver or copper with an alloy of tungsten carbide and titanium carbide. The contact material preferably uses from about 10% to about 90% silver by weight, the remainder being (WTi)C alloy, and preferably the alloy component comprises from about 35% to about 50% of WC, the remainder of the alloy being TiC. The contact is preferably made by a powder metallurgical process, and provides not only good impact resistance, weld resistance and erosion resistance but, even more importantly, provides low contact resistance, i.e. low electrical resistance when current flows through the closed contacts even after repeated cycling, as shown by the low temperature rise of the contact in use.

Abstract: A motor controller having a single set of contacts and two contact operating systems is provided for operation and protection of a motor and the associated circuitry over a complete range of possible currents. For a normal motor starter operation and for fault current up to a predetermined value, an electromagnetic actuator is used to open the contacts a relatively small distance such as 1/4 inch. For higher fault currents a magnetic drive or linear slot motor opens the contacts to a greater spacing such as 1 inch. The slot motor opens the contacts very rapidly giving rise to good current limiting. The disclosed integral motor starter utilizes a bridging contact arm on which are mounted a pair of movable contacts which are aligned to engage a pair of stationary contacts when the disclosed motor starter is closed, completing an electric circuit to the controlled motor.

Abstract: A circuit interrupter having a fixed elongated contact arm, with a fixed contact disposed at the end thereof, and an elongated movable contact arm, with a movable contact disposed at the end thereof, and a magnetic driving device for rapidly separating the contacts. The magnetic driving device is formed of a ferromagnetic material and has a slot formed therein which is magnetically open on one end. The fixed contact arm is partially disposed in the slot near the closed end and the movable contact arm is partially disposed within the slot towards the open end. The magnetic drive or slot motor rapidly separates the contacts upon a predetermined overload. Divergent arc rails lying in the same general plane extend from the fixed contact and the movable contact.