Abstract: An arc spinner interrupter includes a first fixed electrical contact and a ring electrode coupled to the fixed contact through a field coil surrounding the ring electrode. A second electrical contact has an arm which moves along a path perpendicular to the central longitudinal axis for selective connection with the fixed contact. The arm may have a generally L-shaped configuration including an angled portion that extends in a direction parallel to the central longitudinal axis and a conductor extends toward the angled portion through the ring electrode along the central longitudinal axis. The conductor has an inner axial end that is spaced slightly from the angled portion of the arm when the arm is moved to a position intersecting the central longitudinal axis so that a grading function is carried out on the electrostatic field surrounding the angled portion of the arm. This grading function serves to limit the stress exerted by the electrostatic field adjacent the angled portion of the arm section.

Abstract: A low-cost easy to install underpinning apparatus (14) for supporting below-grade structural footings such as foundations (10) or the like is provided which makes use of a power installed, load-bearing helix-type screw anchor (16) together with a connecting bracket assembly (18) secured to the foundation (10). The anchor (16) is screwed into the earth below the foundation (10), leaving the upright end of the anchor shaft (20) adjacent the foundation (10). The bracket assembly (18) advantageously includes a foundation-engaging plate (28) with a pair of spaced, outwardly extending wall portions (30, 32) rigidly secured thereto. An elongated, U-shaped bracket (36) together with a mating retainer (42) are releasably secured to the wall portions (30, 32) and serve to captively retain the upper end of the anchor shaft (20), with the U-bracket (36) having a top crosspiece wall (38) provided with a threaded opening (40) therethrough.

Abstract: A lead element is provided for use with an earth anchor including an elongated rod and an anchor member having a longitudinal hub provided with first and second axial ends and presenting a bore extending axially therethrough, and an outwardly extending load-bearing element affixed to the hub. The lead element includes a first end portion adapted to extend into the bore of the hub to connect with the elongated rod, and a ground-engaging end portion disposed remote from the first end portion and including an offset tip for penetrating earth contacted by the lead element. A radially extending flange is disposed intermediate the first end portion and the ground-engaging end portion, the flange being adapted to engage the hub of the anchor member and including at least one radially extending protuberance constructed to break earth which comes into contact therewith and to move the broken earth toward the load-bearing element of the hub during installation of the anchor.

Abstract: An earth anchor apparatus adapted to be driven by a source of rotational driving force into unbroken soil includes a longitudinally extending hub having first and second axial ends. A recess is provided in one axial end of the hub by which the anchor may be driven, and a radially extending, load-bearing element is affixed to the hub between the axial ends. An earth engaging lead tip extends axially from the second end of the hub and includes a first cutting edge extending in a direction generally transverse to the longitudinal axis of the hub and arranged to cut into and break soil encountered thereby, a front surface extending between the hub and the first cutting edge, and a second cutting edge extending between the first cutting edge and the leading edge of the load bearing element. The second cutting edge is adapted to both cut soil and guide it from the first cutting edge toward the load-bearing element along the front surface so that as soil is cut it is moved away from the unbroken soil.

Abstract: An arc spinner interrupter includes a first fixed electrical contact and a ring electrode coupled to the fixed contact through a field coil surrounding the ring electrode. A second electrical contact has an arm which moves along a path perpendicular to the central longitudinal axis for selective connection with the fixed contact. The arm may have a generally L-shaped configuration including an angled portion that extends in a direction parallel to the central longitudinal axis. The fixed electrical contact is disposed radially outward of the ring electrode so that the generally L-shaped end of the second contact moves generally toward the central longitudinal axis when disconnected from the fixed electrical contact.

Abstract: A sensitive latch and trip mechanism includes a latch plate supported for pivotal movement under the influence of a load, and a latch lever supported for pivotal movement about a lever axis. The lever includes a latching surface disposed in a latching surface plane and a lever axis located a distance A from the latching surface plane in a direction perpendicular to the latching surface plane and offset from the latching surface by a distance B in a direction parallel to with both the latching surface plane and the plane in which the latch plate pivots. A coefficient of friction is defined between the latching surface and a surface of the latch plate interengaged therewith, the coefficient of friction U being correlated with the distances A and B to follow the relationship U.gtoreq. B/A. In this manner, the lever may be easily pivoted from its latching position to unlatch the plate.

Abstract: An electronic sectionalizer includes mounting structure including first and second electrical contacts spaced from one another and electrically conductive structure having an external surface and provided with first and second electrical terminals adapted to engage the first and second electrical contacts of the mounting structure in a closed condition of thesectionalizer. The sectionalizer provides for the release of the electrically conductive structure from engagement with at least the first electrical contact to permit the electrically conductive structure to move from the closed position to an open position, and an actuator is provided for actuating the release. A detector is provided to detect a predetermined condition in the sectionalizier and the actuator is controlled in response to the detection by an electronic control circuit mounted to the external surface of the conductor.

Abstract: Improved switchblade-type, air dielectric switchgear apparatus is provided which utilizes a minimum of supporting insulators and incorporates readily field-replaceable bushing assemblies so that the switchgear apparatus may be serviced in the field using only conventional tools. In preferred forms, the switchgear apparatus includes internal switch assemblies making use of substantially vertically oriented switchblades mounted for pivotal movement about an elevated, generally horizontal axis located above the corresponding stationary contacts. The replaceable bushing assemblies are advantageously mounted at a level for interconnection with the upper ends of associated switchblades, and the assemblies include a conical outermost connection and adapted to receive a line connecting elbow, together with an elongated, inwardly extending, electrically conductive intermediate portion carrying an innermost terminal.

Abstract: An improved, integrally cast, synthetic resin insulator (22) especially adapted for use in an electrical cutout device (20) is provided which can be readily fabricated and gives greatly enhanced beam strength and arc track resistance characteristics. The preferred insulator (22) is cast using an epoxy resin such as bisphenol A filled with a relatively large quantity of glass beads and hydrated alumina. The filler fraction contributes to lowered viscosity, deaerability and improved settling properties while the resin is in an uncured state, and moreover enhances the arc track resistance and mechanical strength of the resin system after curing. The preferred insulator (22) is cast to present a longitudinal bow giving the insulator (22) an arcuate central axis. Further, the periphery of the insulator (22) is formed with a series of superposed, generally oval-shaped in cross-section, outwardly flaring skirts (30) interconnected by smooth transition regions (32) free of stress-inducing sharp corners.

Abstract: A motor operator for local or remote shifting of switchgear contacts toward either open or closed positions includes a reversible motor and rotatable drive screw mounted on common support structure for simultaneous pivoting movement as a drive nut translates fore-and-aft along the length of the screw. The drive nut includes an outer body and an inner sleeve which is set into free-wheeling motion whenever the sleeve comes into contact with either of two stops mounted on the screw defining respective end limits of travel for the nut. A drive element normally coupling the nut to an operating shaft of the switchgear is removable to allow the shaft to be manually rotated with a wrench when desired, and removal of the drive element reduces the likelihood that the worker is injured upon unintentional activation of the motor while the operating shaft is turned by hand.

Abstract: Improved blade-type, air dielectric switchgear apparatus is provided having spring loaded, fast acting, operator independent mechanism for selective opening and closing of internal switch contacts. Preferably, the operating mechanism includes a pair of opposed, pivotal, notched, scissor-like arms with a rotatable latch plate therebetween; a pair of latching pins are carried by the plate, and the latter is operably connected with a power spring assembly. A trip element is also provided which, upon rotation thereof in either a clockwise or counterclockwise direction, serves to shift a corresponding arm away from the latch plate to disengage the latching components. At this point a high velocity rotational movement is imparted to the latch plate by the spring assembly to rotate the latch plate to a second position wherein the plate and the opposed arm come into latching engagement.

Abstract: An electronic sectionalizer mechanism includes upper and lower contact mounting structure, and a sectionalizer tube carrying a logic circuit is telescopically received within the lower contact mounting structure. Once fault current conditions downstream of the sectionalizer mechanism are detected by the logic circuit, an actuator is fired and the tube drops in a longitudinal, non-lateral motion toward an isolated or open circuit position. In preferred embodiments of the invention, a pin of the actuator shifts along an axis parallel to the longitudinal axis of the tube so that immediate drop-out of the tube is assured. The sectionalizer mechanism requires comparatively little space for operating clearances and this is especially adapted for use on a retrofit basis within the confines of an existing subsurface or pad-mounted switchgear cabinet; additionally, the sectionalizer mechanism may also be installed in existing overhead mounting structure for cutouts.

Abstract: An electronic sectionalizer for a branch line of a high voltage power distribution system has a resettable actuator for unlatching a trunnion member and release of a sectionalizer tube toward a disabled or drop-out orientation. The actuator includes an elongated, spring-loaded plunger normally held by a latch in loaded position, and a solenoid or the like is provided to shift the latch and enable movement of the plunger toward a released position for simultaneous swinging movement of the trunnion member. In certain forms of the invention, the plunger is directly engageable with a wall of the trunnion member, while in other embodiments of the invention mechanical advantage is provided by use of an elongated lever which is disposed in the path of the plunger and which bears against the trunnion member for initiating rotational movement of the latter.

Abstract: A mounting assembly for supporting electrical apparatus such as transformers and the like on a utility pole includes spaced, equipment supporting brackets that are interconnected and secured to the pole by means of elongated, toothed plates. End regions of each plate extend through corresponding apertures in the brackets, and during assembly the end regions are shifted laterally and toward a narrowed portion of the aperture until a marginal edge section of the bracket next to the aperture enters a notch between adjacent teeth of the plate. The width of the narrowed aperture portion, being smaller than the overall width of the end regions of the plate except for the notches of the plate between adjacent teeth, prevents unintentional withdrawal of the plates from the brackets. A retaining spring, fixed to the bracket adjacent each aperture, ensures that the end region thereafter remains in place in the narrowed aperture portion in order to facilitate handling of the mounting assembly during installation.

Abstract: A pivot mechanism for drop-out of an electronic sectionalizer tube from an upper contact of mounting structure is arranged so that substantially the entire force released by an actuator fired by a sectionalizer logic circuit immediately causes the tube to drop away and disengage the upper contact. The actuator is mounted on a lower portion of the tube and has a pin that strikes a trunnion pivotally interconnecting a lower contact of the mounting structure and a lower portion of the tube, and the pin of the actuator strikes the trunnion at a location between the pivotal connections of the trunnion so that immediate, downwardly directed motion of the sectionalizer tube away from the upper contact is assured. The pivot mechanism reliably ensures successful drop-out of the tube regardless of adverse environmental conditions and with minimal reliance upon a spring or the effects of gravity.

Abstract: An end cap connection assembly for use in connecting the metallic end caps of an electrical device such as current limiting fuses or lightning arrestors to associated insulative housings is provided which gives a strong mechanical bond as well as a leak-proof seal between these components. The connection assembly includes a cap presenting a continuous, annular, generally U-shaped in cross section housing-receiving groove, along with a relatively rigid synthetic resin sealing adhesive contacting both the groove walls and housing. The rigid adhesive is selected to have a heat distortion temperature closely matching that of the housing. Preferably, sealing material also has a thermal coefficient of expansion profile analogous to that of the housing. In this way the overall sealing assembly can successfully resist leakage resulting from thermal cycling. The sealing assembly of the invention completely eliminates the use of conventional O-rings, gaskets or similar expedients.

Abstract: An end cap connection provides a strong mechanical bond as well as a fluid resistant seal between an electrically insulative tubular member and a conductive end piece or cap. The cap is provided with a generally U-shaped channel, and a quantity of synthetic resin adhesive disposed in the channel contacts an end portion of the tubular member as well as walls of the end cap. In one embodiment of the invention, the tubular member has a generally 90.degree. edge for engagement with outer end cap walls defining the channel, such that as the tubular member is shifted toward the bottom of the channel, curved bottom walls defining the latter maintain the tube at a position spaced from the channel bottom to enable the sealing material to fully contact the inserted end of the tubular member.

Abstract: The velocity of a snap action, spring loaded vacumm switch closing mechanism is substantially reduced by impacting a lever of the mechanism against a first swingable energy absorbing arm which, in turn, pivots to contact a pair of second energy absorbing arms. The pair of second arms are lightweight relative to the first arm and swing through a greater arc than the latter to permit oscillations to subside in remaining components of the switch before rebounding against the first arm. The swingable arms absorb a significant portion of the kinetic energy of the mechanism during closing of the contacts so that shock waves which are normally experienced in various components of the mechanism cannot combine to a value sufficient to snap the mechanism to an open circuit orientation. The anti-bounce device is particularly useful for three phase switchgear wherein a single, common mechanism functions to simultaneously close three pairs of electrical contacts.

Abstract: An improved tower foundation is provided which is inexpensive to manufacture and when installed, serves to securely support a leg of power transmission towers and the like. The tower foundation hereof includes a screw-type earth anchor member having a tubular cavity at the uppermost end thereof. An elongated tower leg connector member is positioned and secured in the cavity of the installed anchor by an initially flowable, solidified material (preferably a sand/epoxy resin mixture). The tower leg connector member advantageously comprises a lowermost, tubular first portion and an uppermost, L-shaped in cross-section second, apertured connection portion, with the first and second portions having approximately coincidental centroidal axes.