Abstract: The wheel speeds are measured by wheel speed sensors and are fed to an evaluation circuit. By way of the evaluation circuit, brake pressure control signals at least for increasing pressure and for decreasing pressure for a specific duration are then produced for the closed-loop/open-loop control of the wheel movement behavior. Moreover, brake pressure control signals are also usually output by the evaluation circuit in order to keep the brake pressure constant. These brake pressure control signals are fed to brake pressure control units for varying the brake pressure. The core of the invention consists in the fact that the duration at least of the first decrease in brake pressure at the front wheels is selected to be dependent on the speed of the vehicle at the start of braking.

Abstract: An optical transmitter for converting a thermocouple voltage into an optical pulse train and a low pass input filter are contained in respective spaces in a soft magnetic housing. The input filter is in lead wires from a thermocouple whose hot junction is embedded in the tip of the insulator of a spark plug of an internal combustion engine. The housing itself forms part of or is connected to the H.T. lead to the centre electrode of the spark plug. The housing is surrounded by insulating material which is itself surrounded by an earthed screening casing. The low pass filter is symmetrically constructed, both electrically and mechanically.The filter prevents interference from reaching the circuitry of the optical transmitter and the housing and the casing prevents the generation and transmission of radio interference.

Abstract: In a spark plug a longitudinal bore is arranged eccentrically in a housing. A housing part with a thicker wall thickness is thereby formed, and a pressure sensor is provided in a bore or this housing part, and therefore the pressure sensor is in direct connection with the combustion chamber. No structural outer changes are required on the housing, so that the spark plug can be installed without any problems in known arrangements.

Abstract: A method of producing a spark plug for internal combustion engines comprising arranging a metal piece formed of a noble material on an end face of at least one metal electrode of the spark plug and directing laser beams onto an outer surface of the metal piece facing the spark gap to form an alloy zone between the one metal electrode and a wear-resistant layer facing the spark gap, the alloy zone consisting of materials of the metal electrode and the metal piece with the proportion of the material of the metal electrode continuously decreasing from an area abutting the metal electrode and consisting only of the metal electrode material, to an area abutting the wear-resistant layer which consists only of the material of the metal piece.

Abstract: A spark plug for use in an internal combustion engine and comprising a movement sensor located in the region of the upsetting and heat-shrink area of the spark plug housing for sensing movement resulting from movement of movable parts of the engine such as pistons, valves, etc.

Abstract: To prevent an increase in diameter or the formation of fissures of resistance wire elements which are placed within a glow sleeve (22) of a glow element (13) during a compaction step in which a pulverized or powder-like heat conductive resistance material (26), for example magnesium oxide, is compacted within the glow element (13) to securely seat the resistance wire (24) therein, the resistance wire (24) is made of a plurality, for example two individual wire elements or strands (24/1, 24/2) twisted together, such that the pitch (27) of the twist is greater than n times the diameter of the number of wire strands twisted together, for example, for two wires, about three times the individual wire element or strand diameter.

Abstract: A sensor (10) optically coupled to the combustion chamber (10') of an internal combustion (IC) engine is kept free from contaminating or dirt deposits, or the like, by subjecting the sensor to mechanical shocks or vibration. The mechanical shocks or vibration are obtained by the engine itself by controlling the engine to operate for a predetermined time period as set by a monostable flip-flop (FF) (18) under controlled knocking conditions, the shock waves within the combustion chamber causing flaking off or dropping off of contaminating deposits. Controlled knocking can be obtained by advancing ignition timing by additional control of an ignition system (19) in a direction of excessive spark advance, or overriding a knocking inhibiting system already present on the engine.

Abstract: To improve operation and output voltage, particularly at 400.degree. C. and less, an oxygen sensor, especially adapted to determine oxygen content of automotive exhaust gases, is constructed by utilizing two electrodes applied on a body of stabilized zirconium dioxide, for example a closed tube, by making an electrode exposed to the exhaust gases in form of a mixture of finely dispersed ceramic material and a platinum-rhodium alloy, the ceramic material being present at about 40% (by volume) and 60% (by volume) platinum-rhodium alloy of 50-94% platinum and 50-6% rhodium (by weight). The second electrode, exposed to a reference gas comprises an alloy of palladium and another noble metal in a ratio of about 19-90% (by weight) Pd and 81-10% (by weight) noble metal. This electrode may also contain up to 40% (by volume) finely dispersed ceramic material. The electrode exposed to the exhaust gases is covered with a porous coating.

Abstract: To rapidly heat glow plugs having positive temperature coefficient characteristics, or glow plugs in circuit with a positive temperature coefficient resistor, without overloading connecting relay contacts, a current limiting resistor is placed in circuit with the glow plugs upon first connection thereof to a supply source. After elapse of a first time interval of about 0.1 to 0.3, maximally 1 second, a second switch is controlled to short-circuit the current limiting resistor to permit full voltage to be applied to the glow plugs for rapid heating thereof, during a second time interval, for example between about 2 to 6 seconds, the positive temperature characteristics of the circuit self-limiting current through the resistors to thereby protect circuit switches and relay contacts.

Abstract: To positively exclude oxygen from a heating spiral located within the interior of a glow plug, so that the heating spiral can use a material having a high positive temperature coefficient of resistance, an insulating bushing separates a central connecting bolt from the surrounding metal sleeve and at least one, and preferably both the bolt and the metal sleeve are formed with circumferential matching ridges and grooves into which the insulating bushing will be pressed to provide an effective seal and a long, tortuous path for any possible leakage of air past the seal, even under the extremes of operating conditions and temperature gradients to which glow plugs are exposed in use. To further exclude oxygen from the heating spiral, the filler material adjacent the sealing bushing can include material having a high affinity to oxygen, such as aluminum or magnesium, so that any oxygen molecules which might leak past the seal will be bound thereby.

Abstract: To heat the glow plug for an internal combustion engine, a spiral band or ribbon is wound in an essentially co-planar spiral about a central bolt secured to the bottom of the glow plug, the outer terminal of the spiral being connected to a lead-in with highly positive temperature coefficient of resistance to provide for self-limiting current flow upon heating of the glow plug. All free spaces in the glow plug are filled with a highly heat-conductive insulating material, for example magnesium oxide.

Abstract: To prevent damage to the heating wire of an electrically heated glow plug due to non-uniform expansion of materials within the glow plug upon heating thereof, and particularly due to excessive expansion of filler material surrounding a spiraled heating wire, the filler material is made in two sections, one being located within the spiral of the heater wire and comprising a material of a thermal conductivity of expansion approximately matching that of the heater wire, typically high-temperature annealed aluminum oxide, magnesium aluminum spinel, silicon nitride, boron nitride, silicon carbide, or the like, the outer section between the heater wire and the inner wall of the glow tube being of a material of good heat conductivity, such as magnesium oxide.

Abstract: To prevent ingress of moisture, water, dirt, or other contamination into the interior of an exhaust gas sensor having an opening to provide for communication with ambient air to establish an oxygen reference level, a cover cap, preferably of metal, but which may be of plastic if extreme heat resistance is not required, is placed over the sensor, the cover cap being formed with a labyrinth which provides for communication between ambient air and the interior of the sensor, the labyrinth preferably being formed as a groove, especially a spiral groove, in the interior of the cap and having access to outside ambient air, the cap preferably being secured by means other than friction, such as a spot weld, an engagement catch or the like to the sensor housing.

Abstract: An RC circuit branch determines the duration of the period for which the primary circuit of a spark coil remains interrupted after the main peak of the spark discharge in the secondary circuit that includes a spark plug. Engine speed and engine temperature are used to shorten the period during which the secondary circuit is allowed to entertain a spark discharge. As engine speed increases the spark discharge period is reduced until a certain speed is reached after which the spark discharge period remains constant with further increase of engine speed. Engine temperature is also used to shorten the spark discharge period by the use of a temperature sensitive resistor. The charging and discharging of the storage capacitor of the RC circuit branch are separately controlled by the shunt circuits in which diodes are interposed and in one embodiment an additional capacitor can be switched into parallel into the RC circuit branch when the engine is starting up.

Abstract: To avoid temperature shock and mechanical damage to oxygen sensors with ion conductive solid electrolytes exposed to the exhaust gases of internal combustion engines, a catalyst, for example in the form of aluminum oxide pellets having a catalyzing surface layer, is located to surround the oxygen sensor, or just in advance of the oxygen sensor in a bypass pipe, branching off from the exhaust gas pipe of the engine to take samples of the exhaust gases so that the sensor and catalyst form an assembly, or sensing combination. The catalyzing layer may be platinum, or a platinum metal, or an alloy of platinum with aluminum, cobalt, nickel, or chromium, or may be mineral wool, or wool of glass, or asbestos fibers having their surface coated with any of the foregoing catalysts.

Abstract: The spark plug center electrode is a composite of a jacket of corrosion resistant material, central filamentary core electrode elements, likewise of corrosion resistant material, and a matrix of thermally and electrically highly conductive material in which the corrosion resistant filamentary elements are embedded, filling the electrode within the outer jacket; in accordance with the present invention, the matrix material is recessed with respect to the jacket and the sparking ends of the corrosion resistant filamentary material to increase lifetime and to provide protection for the electrically and thermally highly conductive material and ensure ignition of even comparatively lean fuel-air mixtures. The electrode has an overall diameter in the order of about 2.4 mm, the recess of the matrix material being between 50 to 500 .mu. m, preferably about 100 to 250 .mu. m; a platinum coating having a thickness of preferably between 40 and 50 .mu. m can be provided to cover the exposed end of the electrode.

Abstract: A thin-walled closed metal sleeve in which a heating wire is placed is attached in a socket which is formed with a bore with a carefully smoothly finished inner surface free from grooves or ridges and accurately dimensioned to a predetermined diameter; the outer diameter of the glow plug sleeve is formed to be just slightly larger and the sleeve is then press-fitted, after having been axially aligned with the bore by axially pressing it into the bore; preferably, the end portion of the bore through which the sleeve is inserted is slightly chamfered or funnel-shaped. The manufacturing step of dimensioning and finishing the bore is preferably carried out by ball calibration, that is, by pressing a hardened steel ball therethrough.

Abstract: To permit use of a standard starting switch customary in Otto engines to start automotive-type Diesel engines requiring energization of a glow plug, the "start" position of the control switch is unstable, for example spring-loaded, and returns the switch to "on" position upon release. The ON position also simultaneously forms the pre-heat switch position. The system includes a first relay having its connecting contacts connected to the glow plug and to a source of power, and a second relay forming a transfer switch with one terminal set connected as a self-holding circuit. The coil of the first relay is connected through the other set of transfer contacts of the second relay to the ON terminal of the switch to form the pre-heat circuit when the second relay is de-energized. The "start" position connects the starting motor.

Abstract: To provide protection to the sensitive solid ion conductive electrolyte, a metal sleeve is placed to surround the electrolyte, with clearance, and formed with openings having an increasing cross-sectional area starting from the housing or socket towards the bottom of the solid electrolyte tube to provide an approximately even temperature gradient upon exposure of the element to exhaust gases, the sleeve being additionally so formed that deflection surfaces or vanes are formed internally thereof, for example by punching the openings through the sleeve as elongated slots leaving deflecting vanes, to deflect gases passing through the openings from direct impingement on the solid electrolyte tube to protect the solid electrolyte tube against impact and contamination.

Abstract: The signals of one or more engine operating parameters, such as r.p.m. and throttle valve vacuum are altered by function generators to correspond to the desired relationship between ignition timing and the parameters that are taken into account. These altered signals are added together and conducted to a comparator that receives as a second input a time and r.p.m. dependent signal from a saw tooth generator, the output of the comparator being fed to the ignition device. .Iadd.