Abstract: An adaptive detection threshold system for moving target detector and moving target indicator radar systems. The threshold system uses data from the echo input signal to reconstruct a threshold level closely resembling the output clutter residue in doppler filters due to point clutter sources. At least three azimuth data values are used, with the values being from adjacent coherent processing intervals and separated in azimuth a distance approximately equal to the beamwidth of the antenna system. The data at the same range from the three azimuths is combined to form an estimate of the residue at the output of a doppler filter, assuming that the echo is caused by point clutter. Compensation for radar instability and changes in scan rate or interpulse period is included. Data from conventional constant false alarm rate processing designed to control alarms from distributed interference, such as weather echoes, is also used to compensate the residue estimate.

Abstract: An acousto-optic tunable filter configuration and a method for the operation thereof, whereby the tuning range is extended. A non-collinear acousto-optic tunable filter crystal has a first transducer bonded to one transducer face of the crystal and a single transducer bonded on the opposite crystal face which crystal face is cut so as to be parallel to the first transducer. The first transducer operates at a center frequency f.sub.1 and the second transducer operates at a center frequency f.sub.2. By launching acoustic waves having a center frequency f.sub.1 into the crystal from the crystal's first side acoustic waves propagate in a first direction such that the interaction of the acoustic wave with the light results in the absorption of a phonon. Acoustic waves having a center frequency f.sub.

Abstract: A method of welding together aluminum alloy workpieces of the same aluminum alloy, and comprises disposing a selected alloying metal on the workpiece in the desired weld area, locally heating the workpieces in the weld area to form a localized liquid solution, and solidifying the localized liquid solution to form the weld between the like aluminum alloy workpieces. The selected alloying metal is silicon for aluminum alloys of interest, and a laser is the preferred heating means for effecting the welding.

Abstract: An on-off keyed carrier signal is demodulated by quadrature sampling of the incoming carrier signal at twice carrier frequency to provide short term digital patterns indicating detection of an incoming signal of carrier frequency. A number of phase counting channels are provided which count the number of times a particular pattern is detected during a longer interval, preferably a sixth of a bit interval at the baud rate of the received message. Since the phase counters are reset every sixth of a bit they can collectively accommodate a substantial drift in phase of the received carrier during reception of a complete 33 bit message while still operating asynchronously with respect to the received carrier.

Abstract: Electrical apparatus is disclosed in which a line voltage supplies current to an electrically operated solenoid through an operable switch interconnected therebetween. A control circuit is coupled to the switch and controls the operation thereof such that the control circuit operates to increase the duration of current flow to the solenoid when the line voltage level decreases. The control circuit includes appropriate circuitry for generating a reference voltage independent of the line voltage level, for generating a control voltage proportional to the line voltage level, and for operating the switch to permit current flow to the solenoid whenever the control voltage exceeds the reference voltage. The control circuit can also include circuitry to increase the duration of current flow to the solenoid upon the occurrence of vibration with the solenoid above a predetermined level, and/or for increasing the duration of current flow upon initial energization of the solenoid.

Abstract: A molded case circuit breaker includes a manually resettable undervoltage trip mechanism for initiating a trip operation of the circuit breaker upon an undervoltage condition. The undervoltage trip mechanism includes a solenoid having a fixed electrical coil surrounding a pair of separable movable ferromagnetic plungers. Disposed between and captured by the two plungers is a compression spring for physically separating the two plungers upon the occurrence of an undervoltage condition. Upon such an undervoltage condition, one of the plungers is positioned to engage and rotate a trip lever for initiating a trip operation of the circuit breaker. The other plunger is secured to an elongated manually depressible reset button that extends through the molded case of the circuit breaker. After a trip operation, the reset button can be depressed to reestablish physical engagement between the first and second plungers, enabling the circuit breaker to be reset.

Abstract: A molded case circuit breaker includes an elongated intermediate latch lever disposed between and in engagement with an intermediate latch plate and a trip bar. The intermediate latch lever is pivotable about a pivot axis and includes a first elongated portion between the latch plate and the pivot axis of a length substantially less than the length of a second elongated portion between the pivot axis and the trip bar. The intermediate latch lever so configured reduces the force required and the amount of travel of the trip bar required to effect a trip operation.

Abstract: A molded case circuit breaker includes an improved system for internally venting gaseous arc products to control the internal gas pressure increase and expansion during an arc interruption. The system includes a first gas expansion chamber disposed proximate to a stationary electrical contact of a pair of separable electrical contacts of the circuit breaker and a second gas expansion chamber disposed proximate to an electrically insulating arc chute barrier that is positioned at an end of an elongated arc chute remote from said stationary electrical contact. The arc chute barrier and the stationary electrical contact are physically configured to effect the rapid internal venting of gaseous arc products to the first and second chambers.

Abstract: A molded case circuit breaker includes an energy or shock absorbing member for assisting in stopping the movable electrical contacts and for preventing severe damage to a movable contact arm or to the molded case of the circuit breaker. The energy absorbing member is secured to an electrically insulating arc chute barrier and is disposed between the movable contact arm and a fixed mechanical stop for absorbing energy due to the rapid movement of the movable contact arm, especially upon a trip operation due to a high level fault current condition.

Abstract: A gas-insulated transmission line includes an outer sheath and an inner conductor disposed therein, which inner conductor is formed from two inner conductor sections electrically connected together. A contact shield surrounds and electrically shields the connection of the two inner conductor sections. Insulating supports spatially support the contact shield within the outer sheath, and the contact shield physically supports the inner conductor sections. The insulating supports thus support the inner conductor through the contact shield.

Abstract: A molded case circuit breaker includes a handle lock or locking mechanism for preventing unauthorized use of the circuit breaker. The locking mechanism includes a lock cover disposed over a manually engagable handle of the circuit breaker and a spring biased locking cylinder and spindle assembly disposed normally above the lock cover and movable along an elongated slot formed through the lock cover. The cylinder and spindle assembly is mechanically connected to the handle for movement in unison therewith. The elongated slot includes an enlarged locking portion that is located along the lock cover in a position corresponding to the OFF position of the handle and the OPEN position of the separable electrical contacts of the circuit breaker. An elongated cylinder of the cylinder and spindle assembly is receivable through the locking portion of the elongated slot and when retained therein prevents substantial movement of the handle from its OFF position.

Abstract: A molded case circuit breaker includes a movable lower electrical contact having a formed stationary member, a movable contact arm, a pair of electrical contact compression springs, a contact arm compression spring and a contact secured to the upper end of the movable contact arm for physically and electrically contacting a separable upper electrical contact. An integral longitudinal end portion of the stationary member extends through the base of the cirucit breaker to form an external terminal of the circuit breaker. The opposite longitudinal end of the stationary member is curved for receiving a rotatable pin fixedly secured to the movable contact arm for rotation therewith. The rotatable pin is biased by the pair of compression springs into effective current conducting contact with the curved end of the stationary member. The contact arm compression spring contacts the underside of the movable contact arm to bias the contact secured thereto into engagement with the upper electrical contact.

Abstract: A molded case circuit breaker includes first and second pairs of separable electrical connectors disposed in adjacent poles of the circuit breaker and spaced apart by a spacing less than the spacing between externally extending electrical terminals for making external electrical connections to the same adjacent poles of the circuit breaker. The closer spacing is achieved by a plurality of integrally formed, molded projections formed in the base of the molded case of the circuit breaker for positioning movable portions of the lower electrical contacts spaced apart in the base by the above closer spacing.

Abstract: A molded case circuit breaker includes a single coil solenoid operator for placing the handle of the circuit breaker in its ON position or in its OFF position. The solenoid operator includes a single coil solenoid formed by an electromagnet secured to a movable electromagnet drive plate and by an armature secured to a movable armature drive plate. The drive plates are disposed for rectilinear movement and are configured alternately to engage a formed trigger plate secured to the handle to move the trigger plate and the handle between the ON position and the OFF position of the handle. A pair of pivotable, bistable mechanical latches are configured to engage and stop further movement of alternate drive plates depending upon the state of the latches. Successive actuations of the single coil solenoid operator cause the handle to be placed alternately in its ON position or in its OFF position.

Abstract: A molded case circuit breaker includes a manually resettable undervoltage trip mechanism for initiating a trip operation of the circuit breaker upon an undervoltage condition. The undervoltage trip mechanism includes a solenoid having a fixed electrical coil surrounding a pair of separable movable ferromagnetic plungers. Disposed between and captured by the two plungers is a compression spring for physically separating the two plungers upon the occurrence of an undervoltage condition. Upon such an undervoltage condition, one of the plungers is positioned to engage and rotate a trip lever for initiating a trip operation of the circuit breaker. The other plunger is secured to an elongated manually depressible reset button that extends through the molded case of the circuit breaker. After a trip operation, the reset button can be depressed to reestablish physical engagement between the first and second plungers, enabling the circuit breaker to be reset.

Abstract: A molded case circuit breaker includes an adjustable stationary lower electrical contact having a one-piece formed conductive contact and a separately formed spacer bracket. One longitudinal end of the formed contact forms an external electrical terminal of the circuit breaker. The formed contact also includes a base portion and a stationary contact arm that has a contact for physically and electrically contacting a movable upper electrical contact of the circuit breaker fixedly secured at its other longitudinal end. The spacer bracket includes a base portion spaced above the base portion of the formed contact by a plurality of deflectable legs. The spacer bracket also includes a contact support portion fixedly secured to the underside of the stationary contact arm. A threaded aperture is formed through the base portion of the spacer bracket for the receipt of a mounting screw.

Abstract: An improved gas-insulated transmission line is disclosed in which the transmission line itself is constructed in a modular fashion from elements which are joined together, typically at the final installation location, to form the transmission line. The other sheath and the inner conductor can be fabricated separately, at different locations and by different manufacturers, and transmitted to the point of final assembly and installation. A backup ring, insulator support assembly, contact shield, and connection member are separately fabricated into a single modular member, which can by itself be subjected to the testing procedures normally undertaken at the factory. This modular member, after satisfactorily passing its acceptance test, can then be shipped to the installation site.

Abstract: A telescoping contact assembly for high current applications includes a center conductor and a coaxial contact sheath assembly. The contact sheath assembly comprises a plurality of spring-loaded elongated contact fingers arranged about the inner circumference of a cylindrical housing. Each spring is loaded so as to create a spring force directed along the length of each contact finger in an axial direction with respect to the housing. Each contact finger is urged against a surface of the housing at a point of contact offset from the line of action of the spring force, thereby producing a radial force component creating contact pressure between each finger contact and the housing, and between each finger contact and the inserted center conductor.

Abstract: A multiple pole circuit breaker comprises stationary and movable contacts in each pole, with a cross bar extending between the poles and causing concerted movement of the movable contacts. An operating mechanism effects movement of the movable contacts between open and closed positions, and a resettable undervoltage release mechanism cooperates with the operating mechanism to effect movement of the movable contacts. The undervoltage release mechanism operates to move the movable contacts from the closed to open position upon the occurrence of voltage levels less than a predetermined value, with the undervoltage release mechanism being reset by physical contact with the cross bar as the cross bar moves with the movable contacts from the closed to open positions.

Abstract: A gas-insulated circuit breaker is described which includes a Y-shaped hollow grounded metal tank formed from three appropriately shaped pipes joined together. A hollow insulating bushing is secured to each upstanding leg. A stationary and a movable contact, separable from each other to establish an arc therebetween, are disposed in one of the upstanding legs, with an insulating gas disposed within both the tank and the insulating bushings. A mechanism is used for directing a blast of insulating gas into the arc established between the separating contact, and includes a piston fixedly disposed in the one leg and a puffer cylinder secured to the movable contact and movable over the piston to compress the gas therebetween. An operating mechanism is associated with the base leg for moving the movable contact, and a drive rod insulatably connects the movable contact and the operating mechanism. The operating mechanism thus moves the movable contact through the insulating drive rod.