Abstract: A method of regulating the valve of the resistance of a thick film resistive element. The resistive element comprises a resistive film (25) which bears on its edge two connection terminals (21, 22) and a connecting bar (24). The variation of the resistance is obtained by forming a slot (23) between the terminals, the slot being substantially perpendicular to the connection bar which connects the two parts of the resistive film separated by the said slot.

Abstract: A device for controlling ignition timing in an internal combustion engine includes a vibration detector responsive to engine vibrations, and comparison means for determining when the output signal of the vibration detector exceeds a base noise output value for that particular cylinder, stored during a previous cycle. The operation of the vibration detector and the comparison means is controlled in response to angular position of the crank shaft so that the base noise value and the detected noise value for each individual cylinder can be determined separately, by defining a given angular position window during which pinging or pre-ignition is likely to occur on any given cylinder. On the basis of the comparison thus effected, the normal ignition advance signal is either unaffected (because no pinging has occurred) or subject to an ignition retardation component (when pinging has occurred) in order to relieve that given cylinder of pinging.

Abstract: A flowmeter comprises a chamber having a rotational symmetry about an axis, provided with a tangential fluid inlet and an axial outlet. The outlet and inlet means cooperate for generating a vortex upon circulation of fluid through the chamber; a speed detector comprises at least one transmitting thermo-element and one receiving thermo-element angularly spaced about the said axis and located in a zone where the circumferential speed of the vortex is proportional to the flow rate.

Abstract: A reduction gear comprises a parallelepiped-shaped casing containing a double worm input shaft engaging with two pinions. The input shaft has its worm portions of equal pitch magnitude but of opposite hand and the engaging pinions are one on each side of the shaft. Alternative positions are provided for the two pinions to enable the direction of rotation of the output shaft to be reversed. Each pinion carries an integral spur gear engaging a common ring gear on which the output shaft is carried. There is a square cover to the casing of the reduction gear and this cover has three bosses for use in mounting the reduction gear on a support frame.

Abstract: An electronic device for detecting and correcting pinking in an internal combustion engine by changing the ignition displacement of the internal combustion engine which comprises a vibration pick-up mounted on the internal combustion engine providing a signal to a band-pass filter for selecting a frequency band corresponding to pinking vibrations and a comparator, the output of which provides a signal for altering the ignition displacement of the engine and the two inputs which receive the output from the band-pass filter after it has undergone different treatments in two parallel channels, one channel comprising an integrator followed by an amplifier and the second channel preferably comprising an integrator, therebeing provided a gate between the band-pass filter and the two channels, which gate is only open for a predetermined angular zone during operation of the internal combustion engine.

Abstract: In an internal combustion engine ignition system having a knock sensor to back-off the ignition advance at the onset of pre-ignition knocking in the engine, the sensor is activated only during a fraction of the power stroke of each piston and the activation is achieved by processing of the ignition triggering signal rather than by incorporation of position sensors on the drive shaft of the engine/gearbox combination. The signal-processing device includes first stage means to generate a signal which is shifted by a constant time relative to the signal which it receives, and second stage means which generates a signal which is shifted relative to the incoming signal by a time corresponding to a constant angle of rotation of the engine (to take into account engine rotation speed) and these stages define the beginning and the end of the periodic signal required for control of the vibration sensor.

Abstract: A magnetic interrupter type transducer for providing an ignition signal with alternating peaks and varying progressively between the peaks. The shape of the signal is a function of the configuration of the opposed surfaces between a rotor and an adjacent pole tip of a magnetic circuit which generates the ignition signal by electromagnetic induction. The variation in volume of the air gap produced during rotation of the rotor provides the signal of the desired characteristics.

Abstract: A high tension generating and distributing device includes a plurality of secondary windings 11, 12, connected to associated ones of the spark plugs of an internal combustion engine, these secondary windings being mounted on a single magnetic frame 1, 2 offering a plurality of flux paths through a low tension primary winding 7 or 8, each of these flux paths being associated with one of the secondary windings 11, 12 and with means, for example in the form of flux gaps 3, 4, 5, 6 or auxiliary windings 213, 214 having associated therewith shunt switches 215, 216, for limiting or cancelling the magnetic flux in some of the flux paths so as to leave one flux path with a higher rate of change of flux than the attenuated rate of change of flux in the other flux paths, thereby selecting the secondary winding associated with the non-attenuated flux path as the one in which the high tension current is to flow.

Abstract: An air conditioning device for an automobile vehicle includes the provision for automatic proportional control of the air conditioning function and also a priority function such as vehicle windscreen demisting or defrosting. Economy of pneumatic power is achieved by providing, with a double threshold control system, a signal for operating pneumatic flow distributors in the driving fluid lines to pneumatic jacks driving the control elements of the air conditioning device by means of an electrical signal which is capable of being either continuous or discontinuous in which latter state the flow distributor to which the discontinuous signal is applied is caused to oscillate to achieve an intermediate pneumatic pressure between pressure values corresponding to fully open and fully closed positions of the air conditioning control elements to be manipulated.

Abstract: The invention provides a distributor device for H.T. supply to an internal combustion engine, and comprising several ignition coils and a single contact breaker to interrupt supply to one or more of those coils at any instant, each of the coils having its primary winding shunted by a thyristor which can be controlled to select whether the primary winding of that particular coil is to be energized, or not, as the case may be.In one embodiment, the thyristors are polarized so as to conduct in a direction allowing "idling" circulation of current through the closed circuit comprising the shunting thyristor and its associated primary winding; in another embodiment the thyristors are polarized in the reverse direction and a diode is connected between the gate and the cathode of each thyristor to protect the cathode from gate voltage and another diode is connected to protect the gating circuit of that particular thyristor.

Abstract: A fluid jet type of carburetor, namely one in which a jet of fuel passes across the combustion air path and has some of the fuel entrained by the passing combustion air and the rest of the fuel recycled, includes means for concentrating the flow of combustion air at the zone of fuel/air mixing where the jet of fuel is exposed to the combustion air. Increasing the degree of concentration of the combustion air at the mixing zone enriches the mixture, and vice versa.

Abstract: A method and apparatus for adjusting a vehicle headlight to maintain the point of intersection of the headlight beam with the roadway at a fixed predetermined distance, and which compensates for changes in both static and dynamic loading of the vehicle.

Abstract: An air conditioning device for an automobile vehicle includes the provision for automatic proportional control of the air conditioning function and also a priority function such as vehicle windscreen demisting or defrosting. Economy of pneumatic power is achieved by providing, with a double threshold control system, a signal for operating pneumatic flow distributors in the driving fluid lines to pneumatic jacks driving the control elements of the air conditioning device by means of an electrical signal which is capable of being either continuous or discontinuous in which latter state the flow distributor to which the discontinuous signal is applied is caused to oscillate to achieve an intermediate pneumatic pressure between pressure values corresponding to fully open and fully closed positions of the air conditioning control elements to be manipulated.