Abstract: A two wire switching system is intended for use in a hostile environment such as a nuclear reactor where temperatures are in excess of 250.degree. or 300.degree. C. and where the use of a switch with a permanent magnet component or a component intended to have remanence is not desirable. The system uses eight reed switches each having three similar windings. No magnetized components are used. The switches are normally closed in the absence of a magnetic field and are opened when a net magnetic field results from current flowing through at least one winding. A pair of conductors interconnects the windings so that each conductor connects certain windings in a series arrangement to ground, giving a unique interconnection for each switch. A control current may be caused to flow in either conductor arrangement at a value of zero or plus or minus A or 2A amperes where A amperes is at least sufficient to cause actuation of a switch when it flows through one winding.

Abstract: Pencil type nuclear fuel elements having a metallic, locally flexible cladding containing discrete fuel pellets in end-to-end packed relation to form a stack of fuel pellets, wherein the pellets are provided with individual expansion provision, to substantially preclude longitudinal expansive movement, are provided with a boundary coat of non-bonding lining material interposed between the pellets and the cladding, to promote peripheral creep of the cladding, relative to the pellets, to reduce the incidence of rupture failure extending longitudinally of the cladding or sheath, due to zero gauge lengths expansion stresses.

Abstract: A process control system providing a particular control effort function is divided into a primary control effort portion having a primary controller, and a feed back from the controlled process to the primary controller, and a secondary control effort portion having a secondary controller in controlling relation therewith, and receiving its control input from the primary controller. The secondary controller is provided with limits such that it becomes saturated in operation, thereby permitting selective overriding by the primary controller, while utilizing the secondary controller and actuators the maximum practical amount. The arrangement is suitable for use with continuously variable devices or for use with on-off (bang-bang) devices. The particular embodiments illustrated are (1) a bang-bang heater system, and (2) a continuously variable fluid flow control system.

Abstract: A directional relay for a polyphase electric power transmission system wherein the direction of a fault from the relaying point is determined by determining the sense of the variation of the zero or negative sequence voltage of the system between the relaying point and the fault point.

Abstract: Apparatus for controlling the starting of a three-phase, salient pole, synchronous motor employs a signal representing slip frequency obtained from a power sensor connected to the motor supply. It requires no connection to the field coil or to other motor component. Since the signal can be obtained from a power sensor, the starting can be controlled from a location remote from the motor, for example at the motor control switchgear. A detector determines when the signal has decreased in frequency to a point representing a rotor speed where field excitation should be applied and it provides an output control signal. This control signal causes field excitation to be applied. In its broadest sense the apparatus may be used to indicate slip frequency remotely.

Abstract: In a domestic two door side by side refrigerator, means for adjusting the curvature of the mullion cover so as to provide thereon a good sealing surface of the doors. The means comprises a spring which biases the mullion cover in a first direction, and a screw element acting upon the mullion cover in opposition to the spring bias.

Abstract: A push-button switch has a wire spring to return the push-button to its non-operated position after operation. The spring is carried by the stem on which the button is mounted and a portion of the spring bears against a fixed ramp. The ramp has first and second portions, the second portion being inclined at a smaller angle to the direction of motion of the push-button than the first portion, against which the spring bears in succession during operation of the push-button such that the force necessary to move the push-button decreases as the push-button is depressed so as to effect a "fall-through" action.

Abstract: Nuclear fuel for use in power generating nuclear reactors is fabricated, using a liquid permeable compressed form, saturating the form with an inert liquid which is a solvent for a desired additive solution, immersing the saturated form within a body of the desired solution for a time sufficient to produce a predetermined diffusion of additive into the form, removing the form from the solution body, and removing the solvent from the form so as to retain a predetermined concentration of additive in the fuel form. This permits the impregnation of pellets with a desired non-uniform addition of material, generally of either a fissile or poisonous nature, to achieve desired in-reactor characteristics for the fuel.

Abstract: A bell and spigot coupling is provided with an abrasive-material insert to increase the disengagement force necessary to uncouple the ducting.

Abstract: A brushholder is adapted to be secured to the frame of a dynamoelectric machine by means of either insulated steel studs or resin-bonded fiber glass studs. The frame of the brushholder contains at least two holes which are spaced apart and in parallel. Each hole is adapted to receive one end of the steel stud as an interference fit or one end of the fiber glass stud as a clearance fit. An adhesive is used to bond the fiber glass stud in the hole. The wall surface defining the hole contains groove means which helps key the adhesive to the surface but does not detract significantly from the interference fit of the steel stud.

Abstract: An apparatus which indicates the sequence of a pair of alternating current input signals by determining the sense of a datum crossing in one input signal with respect to the polarity of the other input signal at the time of the datum crossing.

Abstract: An automatic component insertion machine in which at least some of the component holding units each comprise a plug-in key unit which electrically identifies a respective component type and which is mechanically coded so as to accept only a correspondingly coded packaging stick containing the respective components. The packaging stick may be filled at a testing station which is similarly mechanically coded.

Abstract: In a system for measuring the time delay existing between two pattern related random signals of similar but not identical modulated characteristics, utilizing the techniques of cross correlation, two analogue input signals are digitally quantized into binary form according to signal polarity. The first or leading quantized signal is delayed by a series of sequential time intervals or sampling periods to provide a time controlled sequence of delayed leading-signals at equal intervals. These delayed leading-signals are compared by a multiplication technique with the quantized second or lagging-signal, the occurrence when the signals correspond being summed in a series of overflow counters. The rate of filling of the responsive counters is proportional to the respective degree of correspondence and leads to one counter overflowing first, being indicative of the most probable time delay between the two signals.

Abstract: A television receiver equipped for the display of data transmitted during the line flyback period and also for the display of data transmitted over the telephone via a modem is provided with circuitry for detecting the absence of the normal television synchronizing signals and for providing internal synchronizing to enable the continuance of the display of data.

Abstract: A starting relay for a power transmission line protection system.Where long line sections have to be protected, confusion can arise between normal heavy loads and distant faults having comparable line impedance. The invention provides a starting relay which limits operation of the normal distance relay to conditions within the starting relay characteristic, this being derived by phase and amplitude monitoring of the load at the relay station. The characteristic accepts heavier line currents at potentially normal phase angles than at abnormal phase angles.Certain unbalanced faults do however exhibit normal phase angles and these are detected by substantial line voltage drops. A described combination of phase, current and voltage detectors thus covers substantially all faults.The starting relay finds particular application in a carrier-blocking fault detection scheme employing duplicates of the basic characteristic.

Abstract: An electrical coupling arrangement suitable for connecting protective relays to the primary current transducers in an alternating current power transmission system, comprising three winding arrangements flux linked so that an a.c. input current applied to one winding arrangement provides an a.c. output voltage substantially free of d.c. transients at a second winding arrangement, the third winding arrangement including a resistance which is variable and whose value determines the phase relationship between the output voltage and the input current.

Abstract: A P.C.M. compression-law coder in which sample values in different segments of the dynamic range of the coder are allotted different charging time intervals in an integrator circuit, the segment number forming one part of the resultant encoded signal and digital measure of the discharge time of the integrator circuit at constant current providing another part of the encoded signal.

Abstract: A grass collector for a rotary lawn mower may be moulded in thermoplastic and comprises a base wall, a pair of concentric annular walls upstanding therefrom. A grass inlet is located in the base between the annular walls, and a baffle wall to the rear of the inlet. Grass clippings entering the collector are directed by the walls in an annular flow path and are collected in the annular space between the walls. The collector overlays the deck of the mower and is contained substantially within the wheel base thereof, contributing to increased stability. Safety interlock means for a mower employing the collector are also disclosed.

Abstract: A grass collector for a rotary lawn mower comprises a base and a pair of generally solid and concentric annular walls. A grass inlet is provided in the base preferably of volute form adapted to connect with an outlet in the mower deck. The collector is positioned on the deck of the mower substantially within the wheelbase thereof, contributing to increased stability of the mower, a baffle situated to the rear of the inlet wall interconnects the base and annular walls, a lid for the collector permits the egress of air therefrom.

Abstract: A voltage level detector which detects when a periodic waveform voltage exceeds a predetermined value for a predetermined time and upon detection produces an output, this output being cancelled, after a predetermined delay, if detection ceases. The drop off/pick up ratio of the detector may be reduced by providing feedback from the output.