Abstract: The glow plug comprises a tubular metal sheath (5) closed at the tip, in which an electric spiral (7) is placed as embedded within a powder (6) of electrically insulating material.The filament of the initial length (L.sub.1) of the spiral, from the connection location with the current feeder (4), is coated with high electric conductivity material, the resistance of which has a very high positive temperature coefficient with respect to that of the filament.For the filament an alloy of Fe--Cr--Al is advantageously used and for the coating a Ni-based conductive material.Thus, the end length (L.sub.2) of the spiral acts as sheath heating element, while the initial coated length (L.sub.1) acts as supply current control element.Application: preheating plugs for diesel engines of motor vehicles.Advantages: reduced cost of the glow plug due to construction simplicity. Possibility of varying the electric and thermal characteristics of the glow plug by simply varying the dimensions of the conductive coating.

Abstract: A glow plug for preheating the combustion chamber of a diesel engine includes a tubular metal sheath (5) closed at an end to define a tip and in which an electric heating element spiral (7) is embedded within a powder (6) of an electrically insulating material. The spiral (7) is connected by one end to the sheath tip and and at its other end to a current feeder (4). The filament (8) of the spiral (7) is advantageously made of a Fe-Cr-Al alloy and is coated for an initial length (L.sub.1) of the spiral (7), from the connection location thereof with the current feeder (4), with a high electrical conductivity material (9), preferably nickel (Ni) having a very high positive temperature coefficient of resistance with respect to that of the filament (8). The uncoated end length (L.sub.2) of the spiral (7) acts as a heating element while the initial coated length (L.sub.1) acts as a control resistance element for the supply current upon increase in the sheath temperature.

Abstract: A device for maintaining the electrolyte level in the accumulator of an electric battery includes a pneumatic chamber, with levelling members in it, connected to the accumulator, and a reservoir for supplying liquid to the pneumatic chamber. The levelling members assure a constant level of liquid in the pneumatic chamber. When the electrolyte level in the accumulator drops below a preset limit, the resulting reduction in pressure in the pneumatic chamber permits reservoir liquid to enter the accumulator, until the level of electrolyte in the accumulator rises enough to raise the pressure in the pneumatic chamber to stop flow of liquid into the accumulator.

Abstract: The invention concerns a pneumatic braking system, principally for a towed vehicle, for controlling the timing or sequence of operation of a pneumatic brake. A piston in a cylinder has one face exposed to a towed vehicle air supply and its opposite face exposed to an adjustable pneumatic pressure, a throttling member of a pressure reducer connects both sides of the piston and the chambers on both sides of the throttling member are respectively connected to respective ones of the chambers of the cylinder on both sides of the piston.

Abstract: Shut-off valve unit for damaged section in multi-sectioned pneumatic braking system for vehicles: each section has a shut-off valve that is spring loaded to close; each valve has an associated pneumatic device for loading the spring of the shut-off valve as a function of the pressure downstream of the shut-off valve; the pneumatic device including a shiftable piston under the control of the pressure associated with the other device for the other section of the braking system, such that shifting of the pneumatic device to its position as caused by elevated pressure in the other section increases the load on the associated spring of the shut-off valve of the respective section.

Abstract: An apparatus for controlling the air-gasoline mixture supplied to an internal combustion engine is disclosed. A microcomputer receives a plurality of input signals representative of characteristic magnitudes of engine operation and of the air-gasoline ratio and controls the operation of a metering device as a function of the signals. The microcomputer is programmed with a predetermined feed law to provide predetermined engine performances. The feed law is stored in the form of numerical values, each of which correspond to the metering amount of the metering device which amount has been predetermined to result in the optimum strength of the air-gasoline mixture. The microcomputer is adapted to correct the numerical values in accordance with the difference between the programmed numerical value corresponding to the stoichiometrical air-gasoline ratio and that value which makes it possible to effectively obtain the stoichiometrical ratio under the actual engine operating conditions.

Abstract: Spark advance apparatus for an internal combustion engine utilizes an electronic counter circuit to count pulses generated at a rate proportional to engine speed and also utilizes a device energized by the counter circuit to control the charging time of the ignition coil. The counter circuit includes a first counter that is active until a first count is reached. Thereafter, a second counter of the counter circuit counts a predetermined number of pulses occurring at a frequency relates to a particular engine parameter. The device to control charging of the coil is activated at the end of the count by the second counter.BACKGROUND OF THE INVENTIONThis invention relates to a spark advance apparatus in internal combustion engines comprising an electronic counter circuit for counting frequency pulses proportional to the speed of rotation of the engine and a device for controlling the charge time of the ignition coil as a function of the count.

Abstract: A solid state ignition system for an internal combustion engine is controlled by a spark advance means in relation to one or more parameters affecting spark quality. Supply battery voltage is monitored by the spark advance means whereby the latter generates control signals that regulate primary ignition current so that the latter attains a predetermined level before primary ignition current is interrupted.

Abstract: Apparatus for generating a plurality of pilot signals is disclosed. First and second sets of timers are fed by a common system clock. Each timer of both the first and second sets of timers is adapted to generate a gating pulse a predetermined time period after the initiation of a timing cycle in accordance with a timing characteristic peculiar to each timer. The timing characteristic of the timers in both the first and second sets are chosen such that at least one of the timers in the first set generates a gating pulse at the same time that at least one of the timers in the second set generates a gating pulse. The gating signals generated by each of the first set of timers are applied to one input of each of a plurality of two input pilot signal gates. The gating signal generated by each of the second set of timers is applied to the remaining input of a different one of the plurality of two input pilot signal gates.

Abstract: A system utilizing a single sensor for locating angular positions of a rotating member relative to an angular reference position is provided with means which, for each revolution of the rotating member, generates a bipolar reference signal at the reference position and a bipolar position signal of reversed polarity from the bipolar reference signal. At the second half waves of the bipolar reference and position signals respective unidirectional reference and position signals are generated. The latter are converted to logic signals corresponding to angular positions of the rotating member relative to the reference position and the unidirectional reference signals are utilized to control cycle repetition.

Abstract: A valve to shut off leakage from a damaged section of a pneumatic braking system: the valve comprises a spring biased movable shutter which is spring biased against a fixedly positioned annular seat and a second annular seat coaxial with the first annular seat; the second annular seat is spring biased to move a controlled maximum distance toward the shutter; a plenum defined between the first and second seats and the shutter; a small flow rate leakage passage from the high pressure concuit into the plenum. Pneumatic pressure enters the plenum and raises the shutter off the fixed valve seat while the movable valve seat follows the motion of the shutter and finally the shutter lifts off the movable valve seat, also; upon leakage, the shutter re-engages the movable and then the fixed valve seats. A valving assembly including the aforesaid valve plus other valves in the passages leading to the aforesaid valve, and each of these valves servicing a unit of the braking system.

Abstract: A process for the fabrication of thermistors is described. Conductive wires are positioned in a spaced fashion and are aligned so as to intersect one another. The wires are maintained in the above alignment and placed into a reaction chamber or other suitable environment in which chemical vapor deposition of a semiconductor material by a pyrolysis technique is produced. The temperature of the reaction chamber is preferably just below the temperature level needed to produce the vapor deposition. Electric current is preferably passed through the conductors causing them to heat at the region of the intersections to a level sufficient to induce vapor deposition. The semiconductor material is caused to be deposited upon the conductors in the region of the intersection and is continued until the semiconductor material substantially completely surrounds both of the wires in the region of the intersection so as to mechanically and electrically join the wires.

Abstract: An accelerometer sensor comprising two vertically disposed tubular passages communicating at their bottom; the passages and the connection therebetween being partially filled with a conductive liquid; an electrical resistor in each passage; a conductor communicating into the liquid; an electrical circuit for detecting the resistance unbalance in the resistors, due to the shifting liquid caused by acceleration.