Abstract: A glow plug assembly is disclosed having a plug body for mounting the assembly into an engine. A sheath extends from the plug body and has a distal tip portion spaced from the plug body. A first heating element having a fixed resistance is disposed within the sheath and extends from the plug body into the tip portion. A second heating element having a variable resistance is located next adjacent the tip portion separated from the plug body by the first heating element and connected in series with the first heating element. A terminal extends outwardly from the plug body and a power supply is connected to the terminal. A controller between the power supply and the terminal intermittently applies voltage to the terminal for a predetermined time period to maintain an operating temperature. A sensor senses a combined resistance of the first heating element and the second heating element to maintain the combined resistance with the controller by intermittently applying the voltage.

Abstract: To provide a glow plug capable of speedily increasing the temperature, a glow plug mounting structure, and a process for manufacturing the glow plug.

Abstract: A joint structure which does not exhibit impaired joining strength induced by exposure to heat cycles and the occurrence of migration, in a ceramic heater for a glow plug or like device. A heating element 6 is embedded in a silicon nitride ceramic substrate 5. Lead wires 15 are joined to corresponding lead wire connection terminals 11, which are connected to the heating element 6 while electrical continuity is established therebetween, by use of a brazing metal 20 which contains a predominant amount of copper. The brazing metal 20 used for joining assumes the form of a brazing metal layer having a thickness of 30-400 &mgr;m.

Abstract: A glow plug includes a ceramic heater having a resistance-heating element embedded at its end portion. In order to supply electricity to the resistance-heating element, first and second heater terminals are exposed on the surface of the ceramic heater. First and second terminal rings, which serve as metallic fitting members, are shrink-fitted to the surface of the ceramic heater in such a manner as to cover and be electrically connected to the exposed first and second heater terminals. A metal layer not higher than Ni in ionization tendency is formed on the inner circumferential surface of each of the first and second terminal rings.

Abstract: A glow plug 1 includes a sheathed heater 3 and a metallic shell 2. The sheathed heater 3 is configured such that a resistance wire coil 3b having a heating coil portion 30b and an insulating MgO powder 3d are placed in a sheath 3a and such that a bar electrode 3c is inserted into the sheath 3a. The heating coil portion 30b is formed of a coil base material 31b and a coating layer 32b, which covers the surface of the coil base material 31b. The coating layer 32b is formed of Pt, Pd, Rh, or an alloy of two or more of Pt, Pd, and Rh.

Abstract: Method of joining a rod-shaped heating element with a tubular carrier element involving attaching a cylindrical carrier ring to the rod-shaped heating element using a magnetic forming process and inserting the carrier ring and the rod-shaped heating element into the tubular carrier element such that the outer circumferential surface of the carrier ring contacts the inner circumferential surface of the tubular carrier element.

Abstract: A car cigarette lighter includes a lighter main body, a cylindrical socket body, and a cylindrical case. The lighter main body is selectively inserted into the socket body. An ash disposal hole is formed in the socket body for discharging ash from inside the socket body to the outside of the socket body. The case covers the socket body. A discharge hole is formed in the case for discharging liquid from inside the case to the outside of the case. This prevents ash from being discharged outside the cigarette lighter and lets liquid that has entered inside the cigarette lighter, to be discharged outside.

Abstract: An igniter for use in industrial and domestic gas burning appliances is disclosed. One embodiment of the igniter includes an igniter element disposed on the longitudinal axis of a tubular shield. The shield includes at least one open slot formed therethrough for providing a passageway through which gas and air can flow, thereby forming one or more open spiral patterns in the tubular shield. Another embodiment of the igniter includes an igniter element disposed on the longitudinal axis of a spiral coil. Still another embodiment of the igniter includes an igniter element disposed on the longitudinal axis of a ceramic, cylindrical sleeve. The sleeve includes at least one hole formed therethrough for optimally exposing the igniter element to a gas flow. The tubular shield, the spiral coil, and the ceramic sleeve protect the igniter element from accidental damage or breakage, and allow an optimal flow of gas and air to the igniter element, thereby facilitating subsequent ignition of the gas.

Abstract: A heater has a cylindrical metallic shell, a heater body partly disposed in a front end portion of the metallic shell, an electrode disposed in a rear portion of the metallic shell and electrically connected to the heater body, and a terminal adapted to be capped with an electric connector. The terminal includes a terminal body for power supply to the heater body through the electrode and an engaging portion formed on an outer circumferential surface of the terminal body so as to be engageable with the electric connector. The electrode and the terminal body are formed integrally with each other. Such a heater can maintain good electrical conduction from the terminal to the heater body with its simple structure throughout an extended period of time.

Abstract: A vacuum chamber, such as a semiconductor wafer plasma processing chamber, is heated by use of a ceramic igniter array consisting of a plurality of ceramic igniters positioned in a substrate.

Abstract: A ceramic sheathed-element glow plug includes a ceramic glow element made of an electrically conductive layer and an electrically insulating layer, in which the conductive layer is made of supply layers and a heating layer. The higher specific electrical resistance of the heating layer allows the temperature of the heating layer and of the combustion chamber to be determined, and the electrical contact between a connecting element and the glow element is established by a contacting element that is composed of a pellet made of an electrically conductive powder.

Abstract: A process and device for controlling the heating of the glow plugs of a diesel engine. To be able to take into consideration the thermal behavior of the glow plugs while controlling the current supply of the glow plugs (3) of a diesel engine, the thermal behavior of the glow plugs (3) is emulated via a physical model. Formed on the corresponding output signal of the model (4), which is proportional to the glow plug temperature, is a reference signal, which as a control value, lies on the electronic control (12) controlling the heating flow of the glow plugs (3), which accordingly controls the heating of the glow plugs (3) using the actual glow plug temperature determined from emulation.

Abstract: A method of producing a glow plug including a glow tube (5) with internal heating coil (4) and optionally regulating coils which are embedded therein using a ceramic filling, whereby a compaction of an area on a combustion chamber side of the glow tube (5) is performed using a recessing-reducing process with a radial feed.

Abstract: The present invention provides an inexpensive heater exhibiting good gas-tightness, as well as a method for manufacturing the same. The heater includes a cylindrical metallic shell having a through-hole with a heating element disposed in the through-hole such that a portion projects from one end of the shell. The heater is adapted to generate heat upon application of electricity thereto. A rod-like axial member has a coil lead for electrically connecting a portion of the axial member and the heating element. A gas-tight seal member formed of an insulating polymeric material is interposed between the axial member and the inner surface of the through-hole in such a manner to surround the outer circumferential surface of the axial member. A crimped portion of the metallic shell brings the gas-tight seal member into close contact with the outer circumferential surface of the axial member and the inner wall surface of the through-hole form a gas tight seal.

Abstract: A ceramic heater includes a silicon nitride ceramic substrate and a heating member embedded in the silicon nitride ceramic substrate. An Al-thickened layer is formed in a surface layer portion of the silicon nitride ceramic substrate. The Al-thickened layer has an Al concentration higher than that of an internal layer portion of the silicon nitride ceramic substrate. The Al-thickened layer assumes such a graded composition structure that the Al concentration increases toward the surface of the silicon nitride ceramic substrate.

Abstract: A ceramic heater includes a rod-shaped heater body provided with an insulating ceramic substrate, a heating resistor embedded in a front end portion of the ceramic substrate and a pair of first and second electric conductors embedded in the ceramic substrate with front end portions thereof electrically connected to the heating resistor and rear end portions thereof exposed at a rear end surface of the heater body. The ceramic heater further includes first and second lead-out members having front surfaces joined to parts of the rear end surface of the heater body via metallic layers so as to cover the exposed rear end portions of the first and second electric conductors, respectively, and to be kept from covering an outer circumferential surface of the heater body.

Abstract: Method of joining a rod-shaped heating element with a tubular carrier element involving attaching a cylindrical carrier ring to the rod-shaped heating element using a magnetic forming process and inserting the carrier ring and the rod-shaped heating element into the tubular carrier element such that the outer circumferential surface of the carrier ring contacts the inner circumferential surface of the tubular carrier element.

Abstract: A heater includes a metallic shell, a heating element disposed at an end of the metallic shell, and a terminal electrode electrically connected to the heating element. The terminal electrode has a protruded portion protruding from the metallic shell. The protruded portion has a locking engagement section lockingly engageable with a connector for electrically connecting the terminal electrode to an outside for conduction of the heating element. A method of producing such a heater is also provided.

Abstract: A ceramic heater 2 is arranged in a metallic cylinder member 3 by forming a convergent taper portion 2t at the leading end 2a of the ceramic heater 2 and by positioning the leading end 3a of the metallic cylinder member 3 on the leading end side of a taper starting point P1 of the taper portion 2t. Solder is applied in the clearance between the inner circumference 3d of the metallic cylinder member 3 and the outer circumference 2b of the heater 2. An applied solder layer 10 is also formed on the leading end side of the taper starting point P1 of the taper portion 2t. The thick solder layer 10 present on the leading end side prevents a cut or broken off portion of the ceramic heater from separating or sliding out.

Abstract: A sheathed-element glow plug to be mounted in a combustion chamber is proposed, a rod-shaped heating element being situated in a concentric bore hole of the housing. The heating element has a first current-carrying layer, a second current-carrying layer, and an insulating layer, the insulating layer separating the first current-carrying layer and the second current-carrying layer. The first current-carrying layer and the second current-carrying layer being connected at the end of the heating element on the combustion chamber side by a conducting-layer crosspiece. The first current-carrying layer and the second current-carrying layer are different lengths, the cross section of the first current-carrying layer in a first section at the end of the heating element away from the combustion chamber being greater than the cross section of its remaining length, and the second current-carrying layer not extending into the first section.

Abstract: An electrical resistance ceramic heating element comprises: a) three or more ceramic legs comprising regions of the element in which at least the majority of the electrical heating occurs (hot zones), at least one of the legs being effectively entirely a hot zone and at least two of the legs each comprising a hot zone and a cold zone; b) a number of leg terminal portions less than the number of legs, for connection to a power supply; and, c) ceramic bridging portions providing electrical connectivity between the legs.

Abstract: A glow plug and a process for joining a heating rod of a glow plug to a glow plug body such that a centered force fit between the heating rod and the glow plug body is produced by the radial force acting on the glow plug body.

Abstract: A ceramic heater 1 includes a rodlike heater body 2 configured such that a ceramic resistor 10 is embedded in a ceramic substrate 13. The ceramic resistor 10 includes a front end part 11a and two large-diameter rodlike portions Ld. The large-diameter rodlike portions Ld form passages for supplying electricity to the front end part 11a, extend rearward along a direction of an axis O of the heater body 2, and have an electricity-supply sectional area greater than that of the front end part 11a. The large-diameter rodlike portions Ld each have a connection end part connected to the front end part 11a. The connection end part is formed of a first electrically conductive ceramic and constitutes a first resistor portion 11. The remaining portion of each of the large-diameter rodlike portions Ld is formed of a second electrically conductive ceramic having an electrical resistivity lower than that of the first electrically conductive ceramic and constitutes a second resistor portion 12.

Abstract: A sheath heater in a sheathed-type glow plug for diesel engines is described, having at least one generally internal insulation layer and at least one generally external conductive layer, both layers making up a ceramic composite structure. The sheath heater has a generally uniform overall cross-section, generally over its entire length, and, in the area of a tip of the sheath heater, the proportion of the insulation layer in the overall cross-section increases, whereas the proportion of the conductive layer in the overall cross-section decreases.

Abstract: A glow plug has an outer body with an inner cavity having tapered, sidewalls. An insulating ring having outer tapered walls is held within the body and has an inner opening also having tapered walls. A central electrode, having a tapered wall section, fits tightly in the inner opening of the insulating ring. The insulating ring and central electrode are forced under pressure in the cavity of the glow plug to provide a glow plug capable of withstanding high temperature and pressure applications without leaking.

Abstract: A glow plug according to one embodiment of the present invention includes a cylindrical metallic shell, an electrode rod disposed in a rear portion of the metallic shell, a heater disposed in a front portion of the metallic shell,and an electric insulator provided between an inner surface of the metallic shell and a circumferential surface of the electrode rod to keep the electrode rod insulated from the metallic shell. The metallic shell has a portion caulked to the electrode rod at a location axially corresponding to the electric insulator so that the circumferential surface of the electrode rod becomes deformed to define therein a recessed portion. The caulked portion is engaged In the recessed portion with the caulked portion with the electric insulator interposed between the caulked portion and the recessed portion, thereby securing the electrode rod in the metallic shell.

Abstract: A glow plug comprises a ceramic heater having an insulating ceramic substrate, a heating resistor embedded in a front end portion of the ceramic substrate and a pair of first and second electric conductors embedded in the ceramic substrate and electrically connected at front end portions thereof to the heating resistor, a metallic sleeve circumferentially surrounding the ceramic heater with a front end portion of the ceramic heater protruded from the metallic sleeve, a metallic shell fitted onto the metallic sleeve, and a central electrode partly disposed in a rear portion of the metallic shell. The first and second electric conductors have rear end portions exposed at a rear end surface of the ceramic heater and electrically connected to the metallic shell and the central electrode via first and second connecting members, respectively.

Abstract: A heater comprising: a metal sheath; a heating element that is connected to the inner surface of the metal sheath at one end thereof; a center pole that is extending from an opening of the metal sheath to an interior of the metal sheath and directly or indirectly connected to the heating element; an insulating material that is packed in the interior of the metal sheath; and an elastic packing, wherein the opening of the metal sheath is closed by sealing of a gap between the metal sheath and the center pole with the elastic packing, and an axial length of a portion of the elastic packing, the portion is between the metal sheath and the center pole, is not smaller than 2.5 mm.

Abstract: A ceramic sheathed-type glow plug, whose ceramic heating element is made of an electrically conductive conducting layer and an electrically insulating layer, is described. The conducting layer is made of lead layers and a heating layer. The higher specific electrical resistance of the heating layer allows the temperature of the heating layer and the combustion chamber to be determined. The electrical contact between a connector element and the heating element is established by a contacting element, which is in the form of a pellet made of an electrically conductive powder.

Abstract: A heater comprising: a cylindrical metal shell having an engagement portion, the portion having a narrowed diameter; a cylindrical heating tube comprising a closed top end, a fitting portion, a smaller diameter portion, a base end side-larger diameter portion and a top end side-larger diameter portion, wherein a base end of the heating tube protrudes into an inside of the metal shell, the fitting portion is fitted into the engagement portion in interference fit, the smaller diameter portion comprises the base end of the heating tube, the smaller diameter portion has a smaller outer diameter than an inner diameter of the engagement portion, the base end side-larger diameter portion is formed between the fitting portion and the smaller diameter portion, the base end side-larger diameter portion has an outer diameter larger than or equal to the inner diameter of the engagement portion, the top end side-larger diameter portion is formed adjacent to a top end side of the fitting portion, and the top end side-large

Abstract: A silicon nitride sintered material containing silicon nitride, a Group 4a through 6a element, a rare earth element, and silicon carbide, characterized in that the amount of the rare earth element as reduced to a certain oxide thereof is 5.7-10.3 mol %; the ratio by mol of subtraction remainder oxygen amount calculated in relation to the oxygen contained in the sintered material, the remainder oxygen amount being expressed in terms of silicon dioxide, to the amount of oxygen contained in the sintered material is at least 0.50 and less than 0.70; a four-component crystalline phase of rare earth element-silicon-oxygen-nitrogen is not present; and the thermal expansion coefficient is at least 3.7 ppm/° C. between room temperature and 1,000° C.

Abstract: A ceramic heater 1 is configured such that a ceramic resistor 10 includes a first resistor portion 11, which is disposed at a front end portion of a heater body 2, and which is formed of a first electrically conductive ceramic, and a pair of second resistor portions 12, which are disposed on the rear side of the first resistor portion 11 so as to extend along the direction of the axis O of the heater body 2. The front end parts of the second resistor portions 12 are joined to corresponding end parts of the first resistor portion 11 as viewed along the direction of electricity supply. The second resistor portions are formed of a second electrically conductive ceramic having an electrical resistivity that is lower than that of the first electrically conductive ceramic. At least a portion of a joint interface 15 between the first resistor portion 11 and each of the second resistor portions 12 deviates from a transverse plane P that perpendicularly intersects the axis O of the heater body 2.

Abstract: A sheathed-element glow plug including a glow plug body and a heating rod inside the glow plug body, and a heating element. Optionally, the glow plug includes a control element, embedded in insulating material, associated with said heating element which is positioned within the heating rod. The heating element, at the end facing the electrical connection, has an internal pole, with internal pole lead-in, for connection to a power source; while, the end of said heating element facing the combustion chamber is connected to the tip of the heating rod. The glow plug also includes a contact tube which is pushed onto the end region of the heating rod facing the electrical connection in order to extend the heating rod in the direction of the electrical connection to define a hollow space between the contact tube and the internal pole, internal pole lead-in, which is filled with insulating material.

Abstract: A glow plug (10) for diesel engines that includes a threaded metal tubular body (12) and a metal sheath (22) carried by the tubular body. The sheath (22) has an end portion (24) projecting from the tubular body (12) and is electrically insulated from the tubular body. The glow plug (10) includes first and second electrical terminals (30,46) and a heating resistor (34) electrically connected to the first terminal (30) and to the end portion (24) of the sheath (22). The first terminal (30) has the shape of a metal rod extending through the tubular body (12) and has an end inserted inside the sheath (22). The heating resistor (34) is also set inside the sheath (22). The second terminal (46) is electrically connected to the sheath (22) and can be disposed either coaxially around the first terminal (30) or coaxially within the first terminal.

Abstract: To provide a ceramic heater which is better in the durability of an ion current detecting electrode portion and which can be manufactured at a low cost. A ceramic heater 1 is provided with: an insulating ceramic substrate 13; a resistance heating element 10 buried in the insulating ceramic substrate; and an ion current detecting electrode portion 14 formed integrally with the resistance heating element in the insulating ceramic substrate and having its own surface portion exposed as an ion current detecting face to the surface of the insulating ceramic substrate. The ion current detecting electrode portion 14 is constructed, at its portion including at least a portion of the ion current detecting face 15, of a conductive ceramic phase which is composed mainly of non-metallic conductive ceramic having a cation component made of a nonmetallic element, such as silicon carbide.

Abstract: A glow plug (10) that includes a metal tubular body (12), a metal sheath (24) carried by the tubular body, a heating resistor (33) located inside the sheath, first and second electrical terminals (30,32), and a layer (36) of insulating material applied on a portion of the outer surface of the sheath. The first terminal (30) is electrically connected to the heating resistor (33) and the second terminal (32) is electrically connected to the sheath (24). The layer (36) of insulating material is located on the sheath (24) between the sheath and tubular body (12) to thereby electrically insulate the metal sheath from the metal tubular body. The layer (36) of insulating material can be applied by plasma deposition which enables the sheath (24) to be attached to the tubular body (12) by an interference fit of the sheath within a cavity (16) in the tubular portion. Also disclosed is a method of fabricating the glow plug (10).

Abstract: Process and circuit for heating up a glow plug of a given glow plug type in a given arrangement in an internal combustion engine to a predetermined temperature. The power supply voltage is on the glow plug via a measurement resistor (12) and a switch (11). A control and regulation unit (16) taps the voltage drop via the measurement resistor (12) and determines the heat energy supplied to the glow plug therefrom and from the likewise tapped voltage on the glow plug. The signal which occurs on the output (15) of the unit (16) controls the switch (11). After closing the switch (11) the unit (16) supplies the glow plug with heat energy which is added up in the unit (16). As soon as the heat energy which is required for heating up to a predetermined temperature and which is determined beforehand from the known parameters of the glow plug and from the starting temperature is reached, the switch is opened again via the output signal at the output (15).

Abstract: A heater 1 has a seal structure formed by inserting a shaft-like member 4 into a stepped bore 8 formed in a tubular member 2, and setting an O-ring 16 on an upper surface of a stepped portion of the stepped bore 8, a clearance 15 between the shaft-like member 4 and tubular member 2 being thereby sealed with this seal structure. A seal region 17 is formed on the upper surface of the stepped portion of the stepped bore 8, and a conical introduction port portion 18 extending divergently in the rearward direction from the seal region toward an opening of the stepped bore 8 is provided. Moreover, a cone angle &agr; of the introduction port portion 18 with respect to an axis L of the tubular member 2 is set to not larger than 35°.

Abstract: A silicon nitride—tungsten carbide composite sintered and process for preparing the same which contains silicon nitride and tungsten carbide, and is characterized in that the total in amounts of an entirety of rare earth elements as reduced to certain corresponding oxides thereof, the elements being contained in the sintered material, and excess oxygen as reduced to silicon dioxide is 6-20 mass %; the ratio, on a mol basis, of (the amounts of rare earth elements as reduced to the certain corresponding oxides thereof)/(the amounts of the rare earth elements as reduced to the corresponding oxides thereof+the amount of excess oxygen as reduced to silicon dioxide) is 0.3-0.7; a crystalline phase is present in an intergrain region of the sintered material; and an effective firing temperature range within which a flexural strength of at least 800 MPa is obtained encompasses at least 100 degrees.

Abstract: A method for fabricating electrically conductive silicon carbide articles by doping and sintering submicron silicon carbide particles using sub-micron alumina as the dopant source. Submicron alumina particles are made by milling aluminum powder. Despite the ductility of metallic aluminum, it is successfully ball milled in an aqueous medium through the creation and abrasion of successive layers of an alumina skin to yield alumina particles as small as 0.01 &mgr;m across. When suitably composed mixtures of the silicon carbide and alumina are molded into a green body and heated sufficiently in a non-oxidizing furnace atmosphere, the alumina breaks down to metallic aluminum which diffuses into the silicon carbide. The small particle sizes and the presence of a sintering aid enable rapid processing kinetics which favor saturation of the silicon carbide by the aluminum and inhibit grain growth.

Abstract: A multi-layer ceramic heater for igniting fuel in a diesel engine having an electrode, an insulative layer disposed over the electrode, a resistive layer disposed over the insulative layer at the tip of the heater, and a conductive layer covering the insulative layer and extending from the resistive layer over the insulative layer to the base of heater. A substantial proportion of the volume of resistive layer is located in close proximity to the tip of heater. The resistive layer has a positive temperature coefficient (PTC) of electrical resistance and preferably a portion of the electrode is variably resistive for self regulation purposes. Due to the geometry of the resistive layer and the variable resistive characteristics of the resistive layer and the electrode, the heater is well suited to applications that require quick start heating as well as good afterglow properties or prolonged heating at high temperatures.

Abstract: Rod glow plug with a plug body and an internal heating rod. Between the heating rod (1) and the plug body (7) in the area of a seal seat of the rod glow plug, an electrically insulating shaped part (3) securely adjoins the heating rod (1) supporting the combustion space-side end (7a) of the plug body (7), electrically insulated from the heating rod (1).

Abstract: Low-odor microwaveable mineral-filled polypropylene food contact articles are disclosed. The articles are prepared by low temperature processing and typically include odor-suppressing basic organic or inorganic compounds. Preferably, the articles are substantially free from C8 and C9 organic ketones associated with undesirable odors. Further improvements to the articles include crack-resistant embodiments with synergistic amounts of polyethylene and titanium dioxide.

Abstract: A green ceramic heater including a green heating resistor formed of an electrically conductive ceramic (e.g., suicide or carbide of a metal element such as W, Ta, or Nb) and an insulative ceramic (e.g., silicon nitride) and power supply leads (e.g., made of W), a first end of each power supply lead being connected to a corresponding end of the green heating resistor, the green heating resistor and the power supply leads buried in a green substrate formed of a material (e.g., silicon nitride) is fired, and subsequently, the resultant ceramic heater is heat-treated at 900 to 1,600° C., to thereby enhance flexural strength of the ceramic heater. The heat treatment is preferably carried out prior to forming a glass layer on an outer circumferential surface of the ceramic heater.

Abstract: Glow plug with a glow tube into which an inner pole projects and which is connected via heating and control spirals to the glow tube, the control spirals being located with respect to the heating spirals such that they are uniformly heated over a major portion of their length by the heat from the heating spirals.

Abstract: A sheathed-element glow plug to be mounted in a combustion chamber is proposed, a rod-shaped heating element being situated in a concentric bore hole of the housing. The heating element has a first current-carrying layer (11), a second current-carrying layer (12), and an insulating layer (15), the insulating layer (15) separating the first current-carrying layer (11) and the second current-carrying layer (12). The first current-carrying layer (11) and the second current-carrying layer (12) being connected at the end of the heating element on the combustion chamber side by a conducting-layer crosspiece (13). The first current-carrying layer (11) and the second current-carrying layer (12) are different lengths, the cross section of the first current-carrying layer (11) in a first section (21) at the end of the heating element away from the combustion chamber being greater than the cross section of its remaining length, and the second current-carrying layer (12) not extending into the first section (21).

Abstract: Ceramic igniter compositions are provided that contain components of conductive material and insulating material, where the insulating material component includes a relatively high concentration of metal oxide. Ceramic igniters of the invention are particularly effective for high voltage use, including throughout the range of from about 187 to 264 volts.

Abstract: A sheath heater in a sheathed-type glow plug for diesel engines is described, having at least one generally internal insulation layer and at least one generally external conductive layer, both layers making up a ceramic composite structure. The sheath heater has a generally uniform overall cross-section, generally over its entire length, and, in the area of a tip of the sheath heater, the proportion of the insulation layer in the overall cross-section increases, whereas the proportion of the conductive layer in the overall cross-section decreases.

Abstract: A silicon nitride-tungsten carbide composite sintered material which contains silicon nitride and tungsten carbide, and characterized in that in an arbitrary cross-section of the sintered material, the ratio of the area of a tungsten carbide portion to that of the entirety of the cross-section is 20-35%, and a tungsten carbide aggregation portion having a longitudinal length of at least 5 &mgr;m is present in the arbitrary cross-section. The production process includes firing raw material powder containing tungsten carbide powder and two silicon nitride powders having different particle sizes.

Abstract: A ceramic pin heating element having exterior heating conductors and integrated electrical connection surfaces, and method for making same. A first body is injection molded from a first injection-moldable ceramic composite compound having a first electrical resistance, and a second body is injection-molded from a second injection-moldable ceramic composite compound having a second electrical resistance about the first body so as to form a compound body. The compound body is then sintered. The resulting ceramic pin heating element is directly formed without additional steps for protecting (insulating) the element so as to prevent the exterior, complementary heating conductors from contacting the housing and/or terminal bolts. The danger of breakage of the pins at the mounting location and/or at the seal seat through variations in the thickness of contact and/or insulation coatings is minimized.