Patents Assigned to Sangamo Weston Limited
  • Patent number: 4593959
    Abstract: A digital "signature plug" for applying digital signals representative of shaft characteristics to a digital shaft torque measuring system comprises a printed circuit mounted on an insulating support. The support has an input pin connected to a common printed circuit track, which is connected in turn to sixteen output pins via respective individual printed circuit tracks. The support is shaped beneath each of the sixteen individual tracks to facilitate severing of the track with a punch tool, so that any desired combination of the output pins can be disconnected from the input pin. Consequently, if a logic level 1 signal, for example, is applied to the input pin, any desired pair of eight-bit digital signals can be produced at the output pins.
    Type: Grant
    Filed: October 21, 1983
    Date of Patent: June 10, 1986
    Assignee: Sangamo Weston Limited
    Inventor: David W. Simms
  • Patent number: 4468770
    Abstract: A data receiver is required to detect successive 50-bit frames of data which are transmitted without any pause between frames and with a start bit value of 1 as the only start-of-frame indication. Error detection and correction is obtained by appending at the transmitter a 13-bit check word to 36 data bits (and the start bit), the value of the check word being chosen such that division of the error-free composite 49-bit code word by a predefined generator polynomial yields a syndrome (remainder) of zero. Calculation of a new syndrome value by the receiver at the speed necessary during initial frame synchronization (i.e. for each successive bit) is effected with an iterative procedure in which the previous syndrome value is left-shifted one place and the newly received digit is appended to it; the generator polynomial is added to the result by modulo-2 arithmetic if the most significant digit of the shifted syndrome word is a 1; and the remainder of -2.sup.
    Type: Grant
    Filed: February 24, 1982
    Date of Patent: August 28, 1984
    Assignee: Sangamo Weston Limited
    Inventors: Eric Metcalf, Michael C. Jeffery
  • Patent number: 4464626
    Abstract: In order to allow a wide range of instruments to be assembled from standard modules, there is provided a range of different diameter housings with their glasses spun in and sealed by an O-ring. A housing can be trimmed to length as required. Different types of panel mountings can be fixed over the front rim of the housing. One of a range of standard movements is mounted between plates and matched to the housing diameter and retained therein by releasable catches. The catches may be turnbuttons cooperating with pegs projecting inside the housing. Alternatively, leaf spring catches slidable radially outwardly on the plate can engage in an annular groove inside the housing and be locked in position by clamp screws. The rear end of the housing is plugged by an O-ring sealed base which carries either a terminal part/connector structure only or also a range scaling circuit enabling the same movement to handle different input signal ranges. The pointer on an offset arm sweeps over a scale which can be hub lit.
    Type: Grant
    Filed: August 25, 1981
    Date of Patent: August 7, 1984
    Assignee: Sangamo Weston Limited
    Inventors: David E. Thomas, David M. Jeffrey, David W. Simms
  • Patent number: 4444063
    Abstract: A microprocessor-based torque measuring system for a twin engine-aircraft gas turbine engine installation comprises respective inductive sensors 12,14, one for each engine. The sensors are positioned to co-operate with respective pairs of toothed wheels, which are secured to axially spaced points on the engine shaft whose torque is to be sensed and have interlaced teeth whose spacing circumferentially of the wheels varies with torque. Each sensor produces a torque signal which, after suitable shaping, has a mark-space ratio representative of torque, and the respective durations of the mark and space periods of the signal are measured digitally by counting clock pulses during successive groups of mark periods and space periods. The accumulated counts are then subjected to recursive digital filtering by the microprocessor, in accordance with a predetermined function approximating the response of a second order Butterworth filter.
    Type: Grant
    Filed: August 25, 1981
    Date of Patent: April 24, 1984
    Assignee: Sangamo Weston Limited
    Inventors: David C. Snowden, Joseph J. Osborne, David E. Thomas, David W. Simms
  • Patent number: 4428061
    Abstract: A receiver, for receiving a signal comprising a carrier signal modulated with a digital signal, comprises a circuit for demodulating the received signal to produce an output signal which contains the digital signal. Because of repeated filtering, the digital signal is typically in the form of an approximately sinusoidal signal, which has a component whose frequency is equal to half the basic bit rate of the digital signal: because of noise, this component is subject to considerable timing jitter. To overcome this, the output signal is digitized and applied to a digital correlator, where it is correlated with a reference signal whose frequency is also equal to half the basic bit rate of the digital signal. The reference signal is preferably derived from a phase-locked loop locked to the carrier frequency.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: January 24, 1984
    Assignee: Sangamo Weston Limited
    Inventors: Michael J. Skinner, Jack Woollven, Eric Metcalf, Howard A. Dorey
  • Patent number: 4420721
    Abstract: An electricity meter for metering the amount of electrical energy supplied by a power supplier to a power consumer is provided with fraud detection means for detecting the presence of an external shunt which has been connected to by-pass its internal current sensing means. The detection means, which comprises a differential current sensor for sensing the difference between the respective currents flowing to and from the consumer via the meter and a multiplier for multiplying this current difference by a signal derived from the supply voltage, is arranged to operate a circuit breaker, and/or to compensate the energy measurement of the meter, and/or to provide a warning to the supplier. The differential current sensor also senses when current is being taken between the live wire and earth on the consumer's side of the meter.
    Type: Grant
    Filed: February 9, 1981
    Date of Patent: December 13, 1983
    Assignee: Sangamo Weston Limited
    Inventors: Howard A. Dorey, Anthony J. Ley
  • Patent number: 4419758
    Abstract: A transmission system, for transmitting signals over an electrical power distribution circuit, comprises a transmitter arranged to produce at least two carrier signals of different frequency and to modulate each of them with the same digital signal. The respective frequencies of the carrier signals are derived by frequency division from a common master oscillator, and are thus phase-coherent. The system includes a receiver for receiving the signals, comprising a respective input circuit for each modulated carrier, the input circuits each being tuned to the frequency of their respective carrier signal. A plurality of oscillator signals of different frequencies, derived from a variable frequency oscillator, are used to beat the received carrier signals to respective signals at a common frequency, which signals are summed.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: December 6, 1983
    Assignee: Sangamo Weston Limited
    Inventor: Howard A. Dorey
  • Patent number: 4406924
    Abstract: A radio-controlled device for use in a power distribution circuit, typically for tariff-switching, load-shedding or off-peak load-switching purposes, includes a radio receiver having an aerial circuit which includes a ferrite annulus. The device is typically mounted in an electricity meter connected in the power distribution circuit, with the ferrite annulus surrounding one or more wires of the distribution circuit down-circuit of the meter. The wire or wires surrounded by the ferrite annulus, which typically extend all over the house or other building in which the meter and the device are installed, therefore serve as an aerial for the radio receiver in the device, thus alleviating the problems which can arise when the device is mounted in a location where radio reception is poor.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: September 27, 1983
    Assignee: Sangamo Weston Limited
    Inventor: Howard A. Dorey
  • Patent number: 4388727
    Abstract: A receiver, for receiving a signal comprising a carrier signal modulated with a digital signal, comprises means for demodulating the received signal to produce an output signal which contains the digital signal. Because of repeated filtering, the digital signal is typically in the form of an approximately sinusoidal signal, which has a component whose frequency is equal to half the basic bit rate of the digital signal: because of noise, this component is subject to considerable timing jitter. To overcome this, the output signal is digitized and applied to a digital correlator, where it is correlated with a reference signal whose frequency is also equal to half the basic bit rate of the digital signal. The reference signal is preferably derived from a phase-locked loop locked to the carrier frequency.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: June 14, 1983
    Assignee: Sangamo Weston Limited
    Inventor: Eric Metcalf
  • Patent number: 4001045
    Abstract: A thermocouple having a relatively long thermocouple element portion extending co-axially within an encircling sheath has said portion supported by means which, while not normally movable relative to the element, are in sliding contact with the sheath. The support is preferably one or more thin-walled ferrules secured, for example by brazing, to the thermocouple element.
    Type: Grant
    Filed: March 3, 1975
    Date of Patent: January 4, 1977
    Assignee: Sangamo Weston Limited
    Inventor: George Watson Smith
  • Patent number: 3946259
    Abstract: A stepping motor for use in a remote register, such as is used for the remote reading of electricity meters, is arranged to be advanced by current pulses of known constant polarity. The motor includes magnetic biasing means which effect further rotation of the rotor of the stepping motor in the same given direction each time that an input current pulse ends. The motor can therefore be controlled by a simple ON/OFF switch in the electricity meter circuit with a rectifier being provided in the remote register. The magnetic biasing means may consist of one or more cylindrical magnets co-axial with the rotor, or a straight or arcuate bar magnet adjacent to the periphery of the rotor.
    Type: Grant
    Filed: September 14, 1973
    Date of Patent: March 23, 1976
    Assignee: Sangamo Weston Limited
    Inventors: Maurice Graham McBride, Bernard Herbert Leslie Gray