Abstract: A current limiting device for protecting electrical circuits has a case and a pair of separable electrodes disposed within the case. Each electrode has a plurality of openings with an ablative member abutting the openings at an outer surface of the electrode. A spring is disposed between each ablative member and the case for urging the electrodes together. When the electrical current exceeds a predetermined setpoint the electrodes separate and an arc is created between the electrodes. The arc heats the ablative member causing expulsion of gasses which further increase the gap resistance and cool the arc to thereby quenching the arc. In a second embodiment of the current limiting device, one of the electrodes is a fixed electrode. The ablative member is disposed about a surface of the moveable electrode with a plurality of legs passing through a plurality of openings of the moveable electrode and in contact with an inner surface of the fixed electrode.

Abstract: A penetrating contact design that decreases the time needed to move the male and female contacts of a circuit interrupter from a closed circuit position to an open circuit position. The penetrating contact has a grip-enhancing member that can be located on either the male or female contact. The grip-enhancing member of the penetrating contact maintains physical contact between a male contact and a female contact, while the penetrating contact is in the closed circuit condition. The grip-enhancing member creates a relatively high resistance to separation of the male and female contacts. This separation resistance enhances the separation acceleration of the male and female when they are separated by the circuit interrupter. When an operator initiates a disconnect procedure, this separation resistance will maintain the male contact and female contact in the closed circuit position for a longer time as the interrupter's separation mechanism is energized.

Abstract: A rotary double-break circuit breaker includes a case defining a circuit breaker enclosure with a rotatable bridge and contact arm arrangement. The contact arm having movable contacts which is rotatable between a closed position and an open position. A pair of stationary contacts cooperate with the movable contacts, and a conductor is operatively connected to each of the stationary contacts for current input thereto. Each of the movable contacts includes a heel portion and a toe portion, the heel portion contacting one of the stationary contacts and the toe portion spaced from the stationary contact when the contact bridge is in closed position, the movable contact being angled or curved relative to the stationary contact such that upon the contact bridge rotating to disengage the movable contacts from the stationary contacts, an electric arc formed between the movable contact and the stationary contact runs to the toe portion of the movable contact thereby protecting the heel portion from substantial damage.

Abstract: A contact pin is operationally connected through racks and pinions to a movable mating contact arrangement in such a way that it executes a movement counter thereto. Through two spokes through which the racks are guided, it bears a contact ring which surrounds it coaxially at a distance and preferably has a radius which is four to eight times as large. In a groove on its outer side, the contact ring bears a circumferential spiral contact which forms with the inner side of a contact tube, which finishes in a fixed nominal-current contact, a sliding contact arrangement having good current transfer in conjunction with a short length.

Abstract: The invention provides a persistent current circuit switch of high performance having a small contact resistance. The persistent current circuit switch has a pair of oppositely arranged electrodes and ends of the electrodes are brought into line contact or dot contact with each other. A bore is located at the center of the end of one of the electrodes to reduce the rigidity of the electrode end so that the electrodes can be brought smoothly into contact with each other.

Abstract: In a power switch, power-switch fingers of a rated-current switching arrangement, as well as contact fingers (25) of a tulip contact and a switching pin (14) of an arcing switch arrangement, or other parts, each comprise a base body (26, 28) which, at sections which are subjected to high thermal loads by the arc formation, bears a protective layer (27, 29) which is resistant to contact erosion and has been applied to the base body (27, 28) by plasma spraying in vacuum. This enables even complex and flexible parts to be made resistant to contact erosion. The protective layer (27, 29) which is preferably used is a mixture of at least 10% (by weight), in particular at least 50% (by weight) of high-melting metal, such as W, Mo, Ir, and lower-melting metal, such as Cu, Ag, Ti, Fe, e.g. 80% (by weight) W and 20% (by weight) Cu, while the base body used is preferably made from Cu, Ag. Fe, steel, Al or a flexible copper alloy, such as CuBe, CuCr or CuCrZr.

Abstract: The design of electrical switches that operate under load (with current flowing) requires replacement of the electrical contact after erosion and wear experienced by arcing and raised temperatures reduce functionality below acceptable limits. A quantity of trace element or compound is implanted at a depth representative of the point at which wear or erosion requires contact replacement. When exposed by wear or erosion, the quantity of the trace element is released into the oil or other medium surrounding the contact, providing an indication of excessive wear.

Abstract: In the switched-on position, under the influence of contact forces generated by elastic deflection or else by mechanical spreading, or spreading caused by the attraction of parallel currents or repulsion of antiparallel currents, of a switching pin (5) , the switching pins presses against the inner side of a first switching ring (4), which is rigid for the purpose of avoiding mechanical overloading and securing sufficient consumable reserves. By way of example, a support (30) of the switching pin (5) is adjoined by two parallel, elastic extensions (52a, 52b), which are separated by a slot (53) and respectively support a contact member (54a; 54b) by means of a connecting element (55a; 55b) forming half a screw thread, with the result that said contact member is in each case offset by 180.degree. relative to the extension (52a; 52b).

Abstract: A wreath of contact fingers (4) directed radially toward a switching axis (1) presses in the closed position against the circumferential surface of a contact pin (2) with consumable heads (5) fitted on the ends. At an angle of approximately 90.degree., the contact fingers (4) adjoin webs (6) which are guided in the closing direction up to a housing part (7) at which they are permanently anchored and via which they connect the contact fingers (4) to an electric terminal. The webs (6) and--with the exception of the consumable heads (5)--the contact fingers (4) are produced in one piece from springy material of high conductivity. The contact with the contact pin (2) radially deflects the consumable heads (5) in the closing direction with elastic bending of the webs (6). The length (R) of the radial contact fingers and the length (L) of the axial webs (6) are selected such that the attraction of the parallel component currents through the latter approximately compensates the contact repulsion forces.

Abstract: The design of electrical switches that operate under load (with current flowing) requires replacement of the electrical contact after erosion and wear experienced by arcing and raised temperatures reduce functionality below acceptable limits.A quantity of trace element or compound is implanted at a depth representative of the point at which wear or erosion requires contact replacement. When exposed by wear or erosion, the quantity of the trace element is released into the oil or other medium surrounding the contact, providing an indication of excessive wear.

Abstract: An air circuit breaker movable contact arm assembly is presented. The movable contact arm assembly comprises an electrically-conductive support having at least one slot formed therein to receive a first end of the movable contact arm. The movable contact arm comprises first and second sides which face side walls of the electrically-conductive support within the slot. A spring washer is disposed at the first end of the movable contact arm and loads the second side of the movable contact arm against one side wall of the electrically-conductive support to form a variably conducting joint therebetween. By using a spring washer, the movable contact arm pivotally engages the other facing side wall of the electrically-conductive support to provide a variable pivot point. The variable pivot point of the contact arm assembly permits an additional degree of freedom allowing the movable contact arm to rotate about a separate, variable pivot point.

Abstract: A metal-enclosed, gas-insulated switchgear assembly having at least one active part (19) is mounted in an enclosure extended along an axis (18). The active part (19) is provided on at least one side with a contact-making assembly (25). The contact-making assembly (25a) is electrically conductively connected to a connecting part (26) which is provided with a shielding electrode (28). The shielding electrode (28) is connected to a supporting element (35) which bounds an intermediate area (40). The supporting element (35) is connected, on the side facing away from the shielding electrode (28), to a fitting (37) which has holes (39) which originate from the intermediate area (40) and are designed to hold fixing screws. The connecting part (26) is designed for advantageously simply assembly. The connecting part (26) dielectrically shields the heads of the fixing screws.

Abstract: A contact guide member extends transversely to the contact fingers on the contact carrier of electrical switching apparatus and has spaced openings through which the contact fingers extend and are held in spaced relation. The contact finger guide member is positioned to isolate the arc toes adjacent the free ends of the contact fingers from the main contacts and the contact springs in order to protect the latter items from the arc gases and debris generated during arcing. The openings in the contact finger guide member are elongated to permit differentially pivoting of the contact fingers, but not axial movement. The contact finger guide member slides in a pocket molded in the end face of the contact carrier and is captured by and moves with the contact fingers.

Abstract: A contact device has a pair of flanges which extend inward in the radial direction from both ends of an annular shield, and a plurality of contact pieces which are arrayed in the circumferential direction in a space formed by the shield and the pair of flanges, the axial direction thereof being matched to the parallel direction with the axial center of the shield. Contact sections are provided on the outer peripheral surfaces at both ends of each contact piece. The contact device also has a plurality of rod-shaped elastic members disposed in the circumferential direction on the flanges, each of the elastic members being cantilever-fixed to the flange in such a manner that one end thereof is secured to an inner edge surface of the flange and the other end thereof is allowed to extend along the axial center of the shield into a space formed by the shield and the pair of flanges. The rod-shaped elastic members elastically support the contact pieces to restrict the contact pressure of the contact sections.

Abstract: An apparatus for retaining a movable contact in a circuit interrupter includes a movable element that is displaced by gas pressure within the interrupter housing resulting from arcs generated during initial displacement of the movable element. The movable element may be a spanner extending between two stationary contacts. The apparatus may be configured as a three phase interrupter in which a single carrier or retainer is common to three power phase sections, and is displaced by interruption of a current carrying path for any one power phase section. The retainer may include a retaining pin which extends through the movable element. The movable element is biased into a conducting position and a head of the retaining pin contacts the movable element to hold it in a non-conducting position following a trip event.

Abstract: A gas circuit breaker includes a case body in which an insulating gas is enclosed, a stationary contact part accommodated in the case body and equipped with tulip type stationary contact members, and a movable contact part having a movable contact member. The movable contact member is rotated about a main shaft serving as a fulcrum and makes and breaks a contact with the stationary contacts member, so that a large capacity electrical line can be closed and opened at a high speed.

Abstract: The circuit-breaker has a quenching chamber which is filled with an insulating medium, is of cylindrical design and has a quenching zone extending along a longitudinal axis. In addition, it has a fixed contact arrangement, which is arranged in the course of a main current path, and a moving contact arrangement. Furthermore, a blowing volume is provided which stores the increased pressure of the insulating medium which occurs during a disconnection process. At least one contact link, which has two contact points, electrically conductively connects the fixed contact arrangement and the moving contact arrangement to one another in the connected position. The contact link is also mounted to a holder such that it can rotate. The side of the contact link which interacts with the fixed contact arrangement is acted on by a force directed outward in the radial direction with respect to the longitudinal axis.

Abstract: A contact arrangement is provided for engaging first and second stationary contacts in a predetermined sequential manner, for example so as to appropriately provide a pre-insertion function via the first contact and prior to engagement of the second contact that provides a circuit-closing function in a main current path. In a preferred arrangement, the moving contact of the contact arrangement includes first and second contact surfaces that are spaced apart and parallel to each other, the first and second contact surfaces of the moving contact sequentially engaging the first and second stationary contact surfaces respectively during closing movement. In a specific embodiment, the first and second contact surfaces are provided by a unitary contact member having a circular cross-section, this arrangement being especially suited for a switch where the contact member is rotated as it moves to the closed position.

Abstract: An AC contactor having a high recovery voltage strength includes a contact assembly and a high recovery voltage gas system coupled to the contact assembly. The contact assembly includes two contact pads per electrical phase, with one of the contact pads being attached to a positioning device that selectively disposes the contact pad between a closed circuit position and an open circuit position. The high recovery voltage gas system includes a thermal gas evolving medium for introducing a high recovery voltage strength gas into the gap between the contact pads, which gas has a high glow discharge cathode voltage fall value, as determined for silver-based contacts, of not less than about 300 volts, and typically greater than about 500 volts. The high recovery voltage strength gas typically comprises carbon monoxide, carbon dioxide, water vapor, or the like. The thermal gas evolving medium typically is as a Group IA carbonate (e.g., sodium bicarbonate), and is disposed in the contact assembly.

Abstract: A switch includes a fixed contact having a first conductor portion connected to a terminal, a second conductor portion having a stationary contact, and a third conductor portion. The third conductor portion is disposed on the side of the other end of a moving contact to which a traveling contact is not mounted with respect to a position of the stationary contact, and on the side opposed to the terminal. The first conductor portion is disposed above a contact surface of contacts at a contact closing time, and is disposed below a contact surface of the traveling contact at a contact opening time. A position of the first conductor portion which can be surveyed from a surface of the traveling contact at an opening time of the contacts is coated with an insulator.

Abstract: In an electrical switching device including a stationary contact carrier having a stationary contact mounted thereon, a contact carrier assembly comprises a movable contact carrier and an arc-resistant protective shield. The movable contact carrier has a movable contact mounted thereon. The movable contact carrier is movable between a closed position and an open position. The movable contact abuts the stationary contact while the movable contact carrier is in the closed position, and the movable contact is separated from the stationary contact while the movable contact carrier is in the open position. The arc-resistant protective shield is mounted to the movable contact carrier and surrounds the movable contact. The shield protects the movable contact carrier from electrical arcs generated during circuit interruption.

Abstract: An electrical switch device with separable contacts is provided with a shunt conductor adapted to receive one end of the arc that is struck when the contacts separate after it has jumped a dielectric gap. The shunt conductor determines an interim arc current path in which is a current limiter device.

Abstract: An electromechanical switch of the contactor or circuit-breaker type with adjacent contacts, which are provided on respective mobile and fixed contact parts. This arrangement defines a narrow ionization slot which is maintained at the start of contact opening in order to cause a secondary arc to fire substantially perpendicular to the contact opening direction constituting a shunting arc to eliminate the time duration of the contacts and switch legs.

Abstract: The low-voltage switch includes a stationary contact (2) and a moving contact (3). The two contacts and an arc splitter stack (6) are arranged in an arc quenching chamber (5). An elongation element (14) is fitted on the stationary contact (2), extends in the direction of the arc splitter stack (6) and is used for accommodating an arc root. A section, which is constructed in the form of a plate, of a power supply lead of the stationary contact (2) is widened in a U-shape. The two limbs (11) of the U are bridged by a yoke (12) at their free ends. A conductor element is fitted on the yoke (12), which conductor element is in the form of a plate, is formed by a contact tongue (13) of the stationary contact (2) and by an elongation element (14) fastened thereto, and is inclined in the direction of the arc splitter stack (6) with respect to the plate-shaped section of the power supply lead.

Abstract: A loadbreak switch is provided that utilizes a pivotally mounted movable jaw contact and a main stationary contact that is positioned in the middle of an arc runner. For operation at voltages 15 kV and above, the switch utilizes a shunt contact that bridges the arc runner and that is above and coplanar with the main stationary contact. A magnetic field is developed by the current that flows through a coil of wire disposed around the arc runner. This configuration when utilized in an environment of insulating gas, provides efficient extinguishing of arcs upon opening of the contacts. Further, the open jaw contact is easily visible to establish an open gap.

Abstract: A stationary contact strap for a circuit breaker, with an electrically conductive body portion having a plurality of discrete apertures arrayed in a pattern which define at least two input portions for splitting transient current input into the contact strap into generally parallel pathways which are also in the same general direction as transient current flow in the circuit breaker movable contact arm; and an output portion electrically coupled to the input portions and the fixed stationary main contact, wherein the output portion is oriented so that transient current flow therethrough is in a direction generally opposite to transient current flow in the movable arm.