Abstract: Faults in a three-phase power transmission line are identified by vectorially subtracting from the postfault current for each phase, the zero sequence current and the prefault current. The resultant currents which are the vectorial sums of the postfault positive and negative sequence currents are then compared. If the magnitude of the resultant current in one phase exceeds that in each of the other two phases by a preselected factor, than one phase is identified as the phase to ground faulted phase. If the magnitudes of the resultant currents of two phases exceed that of the third, those two phases are involved in either a phase to phase or a phase to phase to ground fault with the distinction being made by the presence of zero sequence current in the later case.

Abstract: An electrical bushing for use in connection with an electrical apparatus which includes a replaceable stud connector. The replaceable stud has a pair of axially aligned threaded shanks on each side of a flange. The flange on the replaceable stud engages a flange on an electrical conductor in the bushing when one of the threaded shanks of the replaceable stud is threaded into a threaded bore in the electrical conductor, whereby any breakage of the replaceable stud will tend to occur in the other threaded shank.

Abstract: A computer integrated desk having the VDT (visual display terminal), keyboard, disc drives and printer completely concealed within the desk when not in use and quickly convertible to a fully operable computer work station by exposing a keyboard at a central location, raising a flat screen VDT from beneath the work surface and accessing the disc drives and printer by opening a door.

Abstract: A fixture for defining the window of a jointed magnetic core, which core is constructed of amorphous metal alloy, and methods of constructing such a fixture. The fixture includes first and second substantially U-shaped metallic frame members which are easily and quickly assembled with interlocking joints which positively maintain the desired geometric configuration of the core window, as well as the peripheral dimension thereof. Notwithstanding the high mechanical strength of the fixture, the interlocking joints are easily unlocked, which feature is necessary as the fixture will be required to be assembled, disassembled, and reassembled as part of the normal processing of the magnetic core. New and improved methods of constructing the fixture enable the same tooling to be used for different sizes of fixtures, which are required to cover the range of transformer ratings the magnetic cores will be an integral part of.

Abstract: An improved transformer core joint for use in connection with amorphous metal transformers which includes a plurality of spirally wound laminations that are divided into a plurality of groups of laminations. The laminations within a group of laminations essentially provide a butt joint within the group while adjacent groups of laminations form a lap joint with each other. The groups of laminations are divided into sets of groups and a step either in the direction of the spiral or against the direction of the spiral occurs between each of the sets of groups. The joint of the invention provides a compact, easily disassembled and reassembled core joint for accommodating the manufacture of amorphous metal transformer cores.

Abstract: A continuous metal caster cooling system is provided in which water is supplied in jets from a large number of small nozzles 19 against the inner surface of rim 13 at a temperature and with sufficient pressure that the velocity of the jets is sufficiently high that the mode of heat transfer is substantially by forced convection, the liquid being returned from the cooling chambers 30 through return pipes 25 distributed interstitially among the nozzles.

Abstract: A stow away video display terminal in combination with a computer work station or desk wherein the video display terminal is concealed within the desk beneath the work surface in a stored condition when not in use and raised to a viewable position above the work surface by means of a motor driven lift mechanism when it is needed.

Abstract: A concealed keyboard support tray in combination with a work surface wherein a desk pad on the work surface is movable from a position overlying the keyboard support tray to a position rearward of the keyboard support tray to form a work-supporting easel while the keyboard support tray pops up from beneath the work surface to work surface level to provide access to a keyboard situated on the keyboard tray.

Abstract: The wrist includes a first frameless permanent magnet AC powered motor 22 in a first housing 12 with this motor providing movement of a rack 34 along a translational axis A1 with a second frameless permanent magnet motor 42 carried in a second housing 18 connected to the carriage 16 of which the rack 34 is a part so that the housing 18 is movable along an insertion or translation axis A1 with the second motor 42 providing a rotary output. Both of the motors are AC powered and the rotors thereof are each supported solely by a single X type bearing 28 and 48.

Abstract: An improved sensing head structure is provided that utilizes a flexible means for supporting a plurality of electronic components. A bracket is provided that supports the flexible support means in a preselected configuration and also provides a retaining clip portion that fastens a sensing head to the bracket. The bracket is attached to a frame portion of an electric meter in order to support the sensing head at a known position for sensing the passage of a non-reflective band on a rotatable disc under it. The use of two sensing heads permits the rotations of the rotatable disc to be counted and thus provides an apparatus for measuring electrical energy consumption. A spacer bar is also provided for the purposes of allowing the present invention to be utilized to more easily retrofit electric meters having rotatable discs of different sizes and positions within the meter.

Abstract: A two-axis optical wrist which can be used in combination with an industrial manipulator having associated therewith a laser beam delivery system. The two-axis optical wrist for laser application provides two additional degrees of freedom which in combination with a three-axis industrial manipulator provides the five degrees of freedom necessary for industrial material processing laser systems to position a laser beam anywhere within the work envelope of an industrial manipulator.

Abstract: Improved side wall plate members for an adjustable width, continuous casting mold. The adjustable width continuous casting mold is formed of a pair of opposed, spaced apart front and rear mold wall members and a pair of opposed, spaced apart side wall members with the side wall members clamped between the front and rear mold wall members. The improved side wall members of the present invention prevent scratching and wearing of the surfaces of the adjacent front and rear mold walls during mold width adjustment and also prevent twisting or tilting of the mold wall side members during such adjustment. Furthermore, the improved side wall members avoid the formation of flash producing gaps or spaces at the corners of the mold. Each sidewall member according to the present invention, includes, along its side edges, i.e., the edges in contact with the adjacent front and rear mold wall members, a bearing surface formed of a low friction, thermally stable, compressible, memory material.

Abstract: A programmed overexcitation protective relay with selectable time-overexcitation operation to govern the interruption of energy to a piece of power equipment, like a transformer, generator or the like. A programmed processor is included to derive an overexcitation time-to-trip in accordance with sampled measurement voltage values of at least one power line supplying energy to the power equipment being protected, and selected derivation constants stored in a memory look-up table. The derivation constants are selected from the look-up table based on derivation parameters which may be set and read by the programmed processor from time to time. The programmed processor utilizes the selected derivation constants to derive the time-to-trip over a number of predetermined time intervals during which the overexcitation condition persists.

Abstract: A support structure is provided that enables an existing kilowatt-hour meter to be updated with additional auxiliary electronic components. The support structure comprises a base ring that is shaped to be received within a circular slot of an existing kilowatt-hour meter and latches are provided that lock the base ring between the existing base portion of a kilowatt-hour meter and its frame. A plurality of support plates are attached to the base ring by a plurality of posts. The base ring and posts are disposed in a radial pattern about the central axis of symmetry of the base ring in such a way so as to permit the support structure to pass over and extend beyond the existing components of the original kilowatt-hour meter. Electrical connection between existing meter components and auxiliary electronic components is provided by flexible ribbon connectors, cables or individual conductors and an elongated cover is used to provide protection of both the original kilowatt-hour meter and the auxiliary components.

Abstract: Electrical distribution apparatus, such as a pad-mounted electrical distribution transformer, which has an electrically grounded tank or casing. A surge arrester assembly includes a housing, and a draw-out surge arrester having first and second insulatively spaced electrical contacts, with the draw-out surge arrester being removably disposed in the arrester housing. The arrester housing has first and second insulatively spaced metallic end members, with the first metallic end member functioning as a mounting structure for mounting the arrester housing in a tank opening, and as an electrical contact which automatically connects the first electrical contact of the draw-out surge arrester to the grounded tank of the apparatus to be protected. The second metallic end member of the housing electrically connects the second electrical contact of the draw-out surge arrester to an electrical circuit point within the tank to be protected against voltage surges.

Abstract: A time-of-use watt-hour meter is provided with demand profile capability that defines a plurality of survey periods and demand intervals. During each survey period, electrical consumption is measured during a plurality of demand intervals. The highest measured interval demand occurring during each survey period is saved and compared to the highest interval demands for subsequent survey periods. The five highest interval demands occurring during a billing period are saved for inspection by both the electric utility and the consumer. The use of the survey periods and demand intervals has the beneficial affect of avoiding clusters of peak periods occurring during a single sustained period of high electrical consumption. The results of the demand profile data compilation can be viewed at the watt-hour meter or remotely.

Abstract: A microprocessor-based transformer monitoring system to provide continuous on-line monitoring and analysis of transformer operation. The transformer monitoring system periodically monitors various parameters related to transformer load and condition. Maximum, minimum, and instantaneous values of the parameters are stored and analzyed. To perform the analysis, a hierarchy of thresholds is associated with each parameter. When a parameter exceeds any one of the thresholds, a response is produced by the transformer monitoring system. The type of response depends on the level of the exceeded threshold in the hierarchy. The range of response produced by the transformer monitoring system includes: continuing normal periodic data collection and analysis, increasing the rate of data collection and analysis, recommending an on-site physical check of the monitored transformer, reducing transformer load, and taking the transformer off line.

Abstract: A portable remote meter reading apparatus is provided which communicates, via a power line conductor, with remote inaccessible electrical meters. A keyboard is provided to enable an operator to enter command and address information to identify a unique inaccessible meter. A baseband data message is formulated to include the unique address and command information. After being modulated with the high frequency carrier signal, the baseband data message is amplified and injected onto the power line conductor for receipt by a remote meter that is equipped with a transmitter and receiver. In response to the command message, the remote meter transmits electrical energy information for receipt by the present invention.

Abstract: A current limiter is provided which responds to the magnitude of the output current signal from a power amplifier. A full wave rectified signal is provided in response to the magnitude of the current output signal and is used as an input to a comparator. The other input of the comparator is a voltage reference signal that represents a maximum desired current level for the output current signal of the power amplifier. When the output current signal exceeds its reference level, a signal is provided which is used as an input to an exclusive-OR gate which has, as its other input, a modulated square wave signal. The effect of the exclusive-OR gate is to notch the square wave modulated signal in such a way so as to alter its shape. The altered square wave carrier signal causes the MOSFETs of the power amplifier to switch on and switch off at additional occurrences which has the effect of reducing the maximum current level of the output current signal being output by the power amplifier.