Abstract: An inertial platform carries at least one dynamically-tuned free-rotor gyro and is mounted in a three-axis gimbal system. Accelerometers are carried on the platform with their sensitive axes aligned with the two sensitive axes of the gyro. During alignment of the platform, and while the gyro motor is being run up to speed, the output of the gyro pick-off on each axis is combined with the output of the accelerometer on the other axis and applied through a resolver to the appropriate gimbal torque motor.

Abstract: Testing of thin film modules is facilitated by employing predetermined test procedures, so that analysis of the results is facilitated; and the test signals are supplied to, and the corresponding output signals are supplied from, the module terminals, a predetermined interface printed circuit board being connected to these terminals for this purpose, and so that electrical and mechanical damage to the module is obviated during the test procedures.

Abstract: A ring laser comprises a closed optical path defined by two mirrors and a partially-reflecting surface, and one arm of the path includes a laser active medium which produces two counter-rotating beams. The partially-reflecting surface diverts part of each beam by way of an optical energy reflecting device so that the two diverted beams intersect in a plane to produce an interference pattern. An optical grating of similar period to the pattern is located adjacent to and parallel to the plane of the interference pattern, and a detector is located so as to detect movement of the resulting Moire fringe pattern.

Abstract: A contact for an electric connector comprises a terminal element for connection to an electric conductor and a contact-making portion for connection to an electric circuit. The terminal element comprises two arms 10 and 11 joined by a link portion 12 and together defining a parallel sided notch 13. A double bend 23 is formed in the link portion and a second double bend 24 in one arm to produce a notch of the desired width. The contacting-making element may comprise two leak springs 16 and 17 forming a socket contract. A locating member 18 is also provided to locate the contact in a housing.

Abstract: Apparatus for monitoring the acceleration of an aircraft moving along the ground includes a linear accelerometer (FA) and a rate gyroscope (RG). The accelerometer FA is fixed to the frame of the aircraft with its sensitive axis substantially horizontal, and circuit means A3, A4, are provided to null any output when the aircraft is at rest. The rate gyroscope RG is arranged to correct for any misalignment of the axis of the accelerometer, and further circuits A1, A2 null the output of the gyroscope while the aircraft is at rest. An amplifier A5 adds the outputs of the accelerometer and gyroscope channels, and correction amplifier A6 and unit AD correct the output of the summing amplifier A5 for aerodynamic drag resistance of the aircraft at any instant. The corrected output is applied to a suitable indicator such as a meter M.

Abstract: An electric connector includes a housing (10) of elecrically-insulating material having a base (11) and two side walls (12, 13). These define a longitudinal slot (14) into which a plug member (20) may be inserted. A plurality of projecting walls (16) define a number of transverse openings (15) extending from the longitudinal slot (14), and each of these openings contains an electrically-conducting contact member (17) having a contact portion (18) which may extend into the longitudinal slot (14).Control means are provided comprising a bar (22) located in and movable along the longitudinal slot (14), the bar being supported such that such movement causes the bar (22) to rise and fall in the slot. When the bar (22) is in its uppermost position the contact portions (18) of the contact members (17) are retracted from the longitudinal slot (14) into their respective transverse openings (15).

Abstract: Gyroscopic apparatus comprises a gyroscopic device having two mutually perpendicular sensitive axes. The device is suspended in a two-axis gimbal system by means of cross-spring pivots of zero stiffeners. The gimbal system is further supported by a subsidiary suspension about two horizontal axes, and the subsidiary suspension carries damping means to damp movements of the gimbal system.

Abstract: An electric connector comprises a housing (10) having a base (11) and two side walls (12, 13) together defining a longitudinal slot (14) into which a plug member may be inserted. A plurality of projecting walls (15) define a number of transverse openings (16) extending from the longitudinal slot (14), and each of these openings contains an electrically-conducting contact member (17). Each contact member has a terminal portion (18) extending out of the base (11) of the housing (10), a contact portion (19) which may extend into the longitudinal slot (14) and an actuating portion (20).The contact members (17) may be retracted out of the longitudinal slot (14) by an actuating tool comprising a pair of arms (25) which engage with the side walls (12, 13) and, when moved in a direction parallel to the longitudinal slot (14) engage with the actuating portions (20) of all the contact members (17). The front edges of each arm (25) is provided with a ramp (26) to provide gradual engagement.

Abstract: Apparatus for dispensing a preset monetary amount of product, such as fuel, sold by volume and for use with a dispenser which calculates and displays a continuously increasing cost of the delivery has a number of selector buttons which relate to units of cost and which when selected set an appropriate number into a counter. The counter is coupled to the display, and the count is decremented by one for each unit cost of product actually delivered. During delivery of the first unit a store calculates the difference between a unit cost and the cost of a small predetermined volume, which volume is required to be delivered slowly to end the delivery and avoid under- or over-delivery due to mechanical or fluid inertia of the dispenser. When the counter indicates the final unit preselected is being delivered, a comparator compares continuously the cost displayed for that unit and the stored difference and when they are equal the delivery rate is slowed for the final predetermined volume.

Abstract: A unit price setting arrangement for differently priced products available from a remotely located dispenser for example, grades of fuel, from a pump, consists of a central transmitter and a receiver in each dispenser. The transmitter forms a series of fixed length binary words, one for each product, and transmits them in sequence repetitively. Each receiver counts words of the sequence received and compares them with the position of a selected product in the sequence to determine which word relates to the product of interest. That word only is used and is applied to a comparator with a corresponding word stored from a previous transmission to detect a change in the word. A shift register having a stored bit responds to an unsuccessful comparison to shift the bit through one location and a shift through a predetermined number of locations by successive unsuccessful comparisons, if the change is permanent, causes a controller to replace the stored value with the newly received one.

Abstract: Apparatus for controlling the gains of a pair of gain-matched amplifiers includes means for applying a pilot tone of constant amplitude to each amplifier through separate attenuators during a repeated correction time interval. Three control loops are provided, one of which compares the output of one amplifier with a reference signal at times other than a correction time interval to control the gain of that amplifier. A second loop compares the output of the other amplifier with the same reference signal only during each correction time interval to control the gain of the second amplifier. Finally, the third loop compares the output of the first amplifier and the reference signal during each correction time interval to produce a signal controlling the two attenuators.

Abstract: A speed control arrangement for a rotatable member driven by an energy source, such as a spring, whose driving torque can vary consists of an eddy current brake comprising an eddy current rotor driven with the rotatable member and a magnetic circuit coupled to the rotor to exert a braking effect. The magnetic circuit is carried by an arm movable relative to the rotor by unwinding of the spring (or other change in torque) to alter the coupling, and the braking effect, as the torque exerted by the energy source varies.

Abstract: A resistor comprises two identical resistor regions with each resistor region isolated within the semiconductor body by a P-N junction, and with one electrode-bearing end of each resistor region both connected together and to a common region surrounding the resistor regions within the semiconductor body, so that the common surrounding region is to be at the same potential level as the mid-point of the resistor considered as a whole.

Abstract: Apparatus for controlling the gains of a pair of gain-matched amplifiers includes means for applying to each amplifier a pilot tone in the form of an exponentially-decaying periodic signal. The apparatus also includes three control loops, one for comparing the output of one amplifier with a reference signal to derive an error signal used to control the amplifier gains when the pilot tone is absent, and a second for controlling the gains when the pilot tone is present. The third loop subtracts the outputs of the two amplifiers and uses the resulting error signal in conjunction with one or other of the signals from the other two loops to control the gain of one of the two amplifiers.

Abstract: A free rotor gyroscope has a gimbal supported for limited rotation about a rotatable shaft by a first flexure suspension and a rotor attached to the gimbal by a second flexure suspension. Pickoff means rotate with the gimbal and detect its movements about its axis of suspension.

Abstract: In a gas discharge display panel consisting of a matrix of discharge cells defined by gas filled cavities in a block and having cathodes formed by sets of conductors on an end plate sealing the cavities and in which the matrix includes priming cells which are energized to provide from their discharge UV radiation to prime the other cells of the display, at least some of the conductors, except where they form cathodes of the priming cells, are thickened to space the end plate from the block and permit penetration of the UV radiation to the conductors at the ends of the other cavities.

Abstract: An inertia switch comprises a spiral spring-like member supported by a post in a housing, the spring comprising one contact of the switch and the housing the other. The post is insulated from the housing and provides a terminal for the switch. Acceleration or shock applied to the switch causes the spring-like member to move relative to the housing and when it contacts the housing or approaches a detector located inside and supported by the housing, switching is effected.

Abstract: An electric connector for interconnecting two printed circuit boards comprises a socket member for attachment to one board and a plug member for attachment to the other board. The socket member contains a number of rows of rigid contact members, while the corresponding contact members in the plug member are resilient. The resilient members are arranged so that they all deflect in the same direction when the plug is inserted into or removed from the socket.

Abstract: A circuit for digitizing data represented by a variable electric current includes a capacitor to which a variable direct current is applied, and a reference stage defining two voltage levels and producing a control signal when the voltage across the capacitor reaches one of the two levels. The control signal causes the charge on the capacitor to be changed by a known amount. The number of charge pulses is counted and added to the instantaneous value of the capacitor voltage.

Abstract: A servo control system comprising, in a feedback loop, means for providing an error signal representing the difference between desired and actual conditions of a controlled system, and means responsive to said error signal to produce a control signal for the controlled system; the control system also comprising means for injecting a predetermined disturbance signal into the loop, and means responsive to a comparison of said disturbance signal and a loop response signal for varying gain in said loop.