Abstract: Apparatus is disclosed for assembling first and second tubular components in a telescoping, press-fit relationship with each other. The apparatus includes a rotatable, motor driven plate including on the periphery thereof a plurality of component support means, a portion of each being spring biased in a radially outward direction. The two components are partially telescoped into each other by hand and then are loosely mounted on the support means which travel along an arcuate path that is in opposition to a fixed cam having a decreasing radius with respect to the axis of rotation of the rotatable plate. The cam surface bears against and forces one of the components into the other component as the support means move therepast. A movable cam section is also provided to accommodate tolerance variations in the components. The movable cam section is positioned proximate the exit end of the fixed cam and is normally biased in a direction that will push the inner component further into the outer component.

Abstract: An electrical connector is constructed by inserting the end of a stranded cable into a loosely fitted sleeve having diametrically opposed apertures. Thereafter, the sleeve is crimped for securement thereof to the cable. The crimping tool is provided with a punch section that moves through the sleeve apertures and in so doing pierces the cable by spreading the strands thereof, thereby forming a through passage for insertion of a mounting bolt that will be received by a threaded aperture in a terminal. During the crimping operation the sleeve is formed with an extensive flat surface area that will be in intimate contact with the terminal.

Abstract: A combination motor starter connecting a three-phase motor to a source capable of delivering short circuit currents of approximately 100,000 amps is constructed of a molded case circuit breaker having a magnetic trip means, an electromagnetic contactor, overload relay means, and fusible short circuit protector means, all connected in series. The overload relay means brings about opening of the contactor upon the occurrence of overload currents, the magnetic trip means brings about opening of a circuit breaker upon the occurrence of fault currents that the other elements of the starter circuit can withstand without damage for as much as one cycle, and the protector means opens the circuit under severe fault current conditions in a time interval sufficiently short to prevent destruction of any reusable circuit elements. Each pole of the protector means includes a fusible element connected in parallel with a resistor.

Abstract: An artificial neutral voltage derived from the voltages on both energized lines of a three-wire, single-phase energy supply system is compared to the voltage on the neutral line. Comparator means energize interrupter means to cause the cessation of a current flow in the energized lines of the circuit in the event the neutral line voltage is more than a predetermined value above or below the artificially derived neutral voltage for protection in the event an open neutral line condition occurs even when loads are not attached to the energized power lines.

Abstract: A unitized combination motor starter is provided with a single insulated housing wherein a plurality of pole units are disposed side-by-side. Each pole unit includes a circuit breaker contact section and a contactor contact section. A spring powered mechanism for circuit breaker operation is disposed on one side of the pole units and an electromagnet for contactor operation is disposed on the other side of the pole units. The current carrying elements of each pole unit are arranged to provide a current loop having relatively close opposing arms so that large mechanical forces accompany high magnitude current flow. These forces are directed so as to produce a blow-off effect at the circuit breaker contacts, resulting in current limiting action to protect the contactor contacts.

Abstract: A puffer interrupter has two axially spaced movable pistons fixed to the movable contact. A fixed barrier is disposed between the two pistons and a further fixed barrier is positioned at the end of the cylinder chamber. The two fixed barriers form three variable volume chambers with the two movable pistons. As the interrupter is opened, the central chamber formed between the end movable piston and fixed barrier between the two pistons reduces in volume to generate an increasing pressure while the two volumes on either side of the central volume increase in volume to produce a decrease in pressure. Gas then flows axially through the separating contact from the decreased volume central chamber to the outer reduced-presssure chambers. An auxiliary piston is formed within the central chamber and can increase the central chamber volume when the pressure within the central chamber exceeds a given value due to blockage of the nozzle by high arc-generated pressures.

Abstract: A grounding and test switch for a fully enclosed pressurized gas insulated high voltage system wherein the conductors are completely isolated in an SF.sub.6 or other gas insulating environment. The grounding switch is provided with a contact arm and a movable contact within the enclosure to engage a stationary contact connected to or on the conductor or device inside the enclosure. The contact arm is operable through a gas tight seal from outside the enclosure. The contact arm slides with respect to another stationary contact which provides a direct and positive electrical connection thereto so that the contact arm, when engaged with the first mentioned stationary contact forms a conducting bridge to ground between the first mentioned and second mentioned stationary contact.

Abstract: An electrical conduit grounding assembly includes a grounding cable parallel to and laterally offset from the conduit and a pair of longitudinally extending dihedral angle clamp members provided with longitudinally serrated confronting concave faces which embrace the conduit and have interdigitating hinge knuckles along their proximal longitudinal edges engaging the grounding cable. A screw engages a tapped bore and an opening in distal wings on the clamp members to permit their tightening. Longitudinal slots may be formed in the knuckles to facilitate their application to the grounding cable.

Abstract: An electrically releaseable permanent magnet latch includes a magnetic tube disposed within a U-shaped magnetic frame. Disposed within the tube are a lightweight armature and a coil spring biasing the armature forward. An electromagnet coil is wound about the tube and a pair of permanent magnets are inside the frame outboard of the tube. Magnetic diverter plates abut the magnets and are interposed between the magnets and coil. A collar on the tube provides a direct magnetic bridge to the diverters. Energization of the coil creates a flux which bucks the permanent magnet flux to permit the spring to overcome the armature holding force whereby the spring operates the armature.

Abstract: The gas-filled bushing of a two-pressure circuit breaker has a hollow central conductive stud. Gas is injected into the annular chamber between the stud and the porcelain jacket of the insulator at the insulator flange, and the chamber is isolated from the interior of the circuit breaker housing. This gas flows up to the top of the bushing and into the open center of the conductive stud, and down into the low-pressure housing of the circuit breaker. A gas orifice restricts the flow of gas into the bushing to a small value and a compressor maintains a given pressure differential between the low-pressure gas and its high-pressure source.

Abstract: The gas-filled bushing of a two-pressure circuit breaker has a hollow central conductive stud. Heated gas is injected into the annular chamber between the stud and the porcelain jacket of the insulator at the insulator flange, and the chamber is isolated from the interior of the circuit breaker housing. This gas flows up to the top of the bushing and into the open center of the conductive stud, and down into the low-pressure housing of the circuit breaker. A gas orifice restricts the flow of gas into the bushing to a small value and a compressor maintains a given pressure differential between the low-pressure gas and its high-pressure source. The heated gas maintains the gas in the bushing and in the housing at a temperature greater than -40.degree.F.

Abstract: Inner conductors of isolated phase bus sections arranged end to end are joined by a multiplicity of longitudinally extending, annularly arrayed contact fingers which are biased radially inwardly against the conductors being joined with one end of each finger riding in a groove provided therefor on the exterior of one conductor and the other end of the finger being biased against the end of the next adjacent conductor to make slidable contact engagement therewith; a single dielectric shield surrounds both ends of the conductors and the contact fingers and is non-rigidly fastened at its longitudinal ends to the respective shells around each of the endwise adjacent conductors; springs extend between the shield and the fingers to bias the fingers against the conductors; the shield and finger arrangements permit the maximum width for the inner conductors enabling maximum quantities of contact fingers to be used and this arrangement also permits great misalignment between conductors, or tilting of one conductor wit

Abstract: A rotary handle operator mechanism is fixedly mounted in an enclosure having a circuit interrupter mounted therein on the rear wall thereof. The mechanism includes a main handle disposed outside the enclosure for manual operation and being keyed to a cam unit engaged with the circuit breaker handle. A latch unit, including a cover latch section, is provided with a notch formation and a cam formation that cooperate with a forwardly extending pin of the cam unit to provide a switch interlock and a cover latch release.

Abstract: A ground fault detector-interrupter, including a differential transformer for detecting the difference between currents in the hot and neutral conductors connecting a load to an a.c. source, is provided with a resistor shunting the differential transformer primary winding in series with the hot conductor. By shunting part of the current in the hot primary around the differential transformer, the transformer is effectively desensitized under high in-rush current conditions to protect against false triggering that would normally be caused by non-uniformity in the transformer windings and/or less than precise placement of transformer leads.

Abstract: An insulation housing has a central opening to allow the housing to be mounted on a high voltage conductor. A continuous, circular cylindrical electrode band is embedded within the housing and is capacitively coupled to a conductor which passes through the central opening of the housing. The electrode may be the sole electrical component encapsulated within the housing. The lead from the electrode is then coupled to indicators which are fixed on remotely positioned switchgear cubicles. The indicators include neon glow bulbs and a solid state relay which are operated by the energy derived from the capacitive pickup structure.

Abstract: A rotary handle mechanism for operating a switch device secured to the rear wall of an enclosure is mounted separate from the enclosure cover and extends through a cover opening to be operable from outside of the enclosure when the cover is closed. The mechanism is designed so that the elements thereof may be assembled selectively for operation within an enclosure having a cover that is hinged along one or the other of its edges.

Abstract: A static relay utilizing a resistance-capacitance network to provide a current-time characteristic which has an inverse relationship for appropriately controlling protective operations in power transmission and distribution networks. An integrated dual-threshold and clamp circuit is employed in the static relay to adjustably control the time delay characteristic of the network over a range of several orders of magnitude without altering the time delay wave shape or requiring matched components and incorporates linear time setting means to facilitate adjustment and usage of the static relay.

Abstract: The insulation nozzle of a puffer type breaker has flexible contact fingers disposed along the walls of the nozzle upstream of the gas flow path through the nozzle. The flexible contact fingers engage a hollow tubular stationary contact which extends through the nozzle orifice when the interrupter is closed. A central arcing contact is fixed to the flexible contact fingers within the nozzle and projects into the interior of the stationary tubular contact when the contacts are closed. A plurality of main finger contacts are connected to the stationary contact, and slidably engage an outer main movable contact sleeve fixed to the movable arcing contact and the insulation nozzle. The movable contact sleeve forms a bridging connection between the main terminals of the interrupter when the interrupter is closed. The main bridging contacts disengage before the interior contact fingers within the nozzle disengage the stationary contact tube so that the outer fingers do not interrupt power currents.

Abstract: A circuit breaker module and a detector module are mounted side by side to form a ground fault interrupter. The detector module includes an electromagnet for mechanical engagement with operation of the automatic trip device of the circuit breaker to open the latter upon the occurrence of predetermined ground fault conditions. An indicator member is pivotally mounted between the detector and circuit breaker modules. When the electromagnet is energized, it moves the indicator member from a retracted to an indicating position. In the latter position a portion of the indicator member is readily visible to indicate that tripping has resulted from a ground fault rather than from an overload.

Abstract: A cradle type wire grounding lug is secured to the periphery of a conduit fitting such as a bushing. The lug has a body with a generally C-shaped cross section for the wire clamping portion and has a mounting tang extending outwardly and angularly offset from the base of the C-shaped portion with a mounting screw opening in the tang for securing it to the periphery of the bushing. A binding screw extends down through the top flange of the C-section generally transverse to the ground wire receiving groove along the bottom flange of the C-section, which has an opening concentric to the binding screw opening. The mounting tang is offset about 30.degree. from the plane which contains the base of the C-section.