Abstract: A device for an adjustment of a heater control includes a nominal parameter provision unit designed such that it provides at least one nominal parameter value, an actual parameter detection unit designed such that it is able to detect for at least one of the nominal parameter values the corresponding actual parameter value in a heater control or in an additive manufacturing device, wherein an actual parameter value is the actual value of a controlled variable and/or the actual value of its change with time and/or the actual value of a heater parameter and/or the actual value of its change with time, and a control change unit that automatically changes at least one control parameter value, if a predefined difference between the nominal parameter value and its corresponding actual parameter value is exceeded.

Abstract: An exterior aircraft light unit (2) includes a lens cover (50) and at least one light source (6, 6?) for emitting light through the lens cover. The lens cover has an aerodynamic front edge (52), separating an impinging air stream during flight, and an aerodynamic front region (54) around the aerodynamic front edge. The light emitted by the at least one light source exits the lens cover only outside the aerodynamic front region.

Abstract: The invention relates to a headlight for a vehicle, comprising a concave reflector and a lamp arranged within the reflector to reflect light from the lamp to create an illumination beam with a bright/dark boundary. The lamp comprises a transparent vessel including a longitudinal axis, at least a first and second filament arranged within the vessel. A baffle arranged proximate to the first filament, and comprising first and second upper side edges. The first filament is arranged above a plane including the upper side edges. A different plane is through the center of the first filament and is arranged perpendicular to the longitudinal axis. The upper side edges are arranged symmetrically to a baffle symmetry axis extending from the center of the first filament centrally between the upper side edges. The lamp is arranged within the reflector rotated around said longitudinal axis by a rotation angle of 2°-20°.

Abstract: A display device includes a display panel, a bottom chassis supporting the rear of the display panel, a light source disposed on at least one side of the bottom chassis, a reflective member disposed between the display panel and the bottom chassis and having a reflective surface for reflecting light emitted from the light source to the display panel, and a reflective holder for fixing one end of the reflective member, the reflective holder reflecting light directed toward the reflective holder to the display panel.

Abstract: The present seam visually suppresses a gap defined between two adjacent reflective surfaces. The seam comprises a strip of light propagating material and a plurality of lighting units. The strip of light propagating material defines a front surface, two side surfaces and a back surface. The side surfaces of the strip of light propagating material is adapted for being positioning in the gap defined between the adjacent reflective surfaces. The lighting units are positioned along the back surface of the strip of light propagating material and are adapted for propagating light in the strip of light propagating material. When light is propagated in the strip of light propagating material, the gap between the two adjacent reflective surfaces is visually suppressed.

Abstract: A brush for a starter-generator includes a first carbon block, a second carbon block, a terminal lug, and a plurality of brush leads. Each carbon block has an outboard edge and an inboard edge. Each carbon block includes a front carbon wafer and a rear carbon wafer. Front brush leads connect the terminal lug with the front carbon wafers of the respective carbon blocks adjacent the inboard edges of the respective carbon blocks. Rear brush leads connect the terminal lug with the rear carbon wafers of the respective carbon blocks adjacent the outboard edge of the respective carbon blocks.

Abstract: The present image generator visually suppresses a gap between two adjacent reflective surfaces of a reflective display. The image generator comprises memory and a processor. The memory stores position of the gap on the reflective display. The processor analyzes a stream of images to be displayed on the reflective display and determines corresponding lighting data alongside the gap. The processor further controls at least one lighting unit located behind a seam inserted in the gap based on the determined lighting data.

Abstract: A lamp for automotive front lighting and a vehicle headlight comprising the lamp are described, as well as a method of manufacturing the lamp. The lamp 10 comprises a base 12 for mechanical and electrical connection to an automotive headlight 50. A burner 14 is fixed to the base 12 and comprises a sealed transparent vessel 22. A first filament 34 is arranged within the vessel 22. A holding wire 30c is arranged within the vessel, and a baffle 40 is arranged proximate to the first filament 34 to partially shield light emitted from the first filament 34. The baffle 40 is fixed to the holding wire 30c. The transparent vessel 22 comprises a vessel wall including a cylindrical portion 24 surrounding the first filament 34. In order to obtain a lamp which may withstand vibration, a support member 38, 138, 238 is provided including at least a first part 39 fixed to the baffle 40 or to the holding wire 30c and a second part 43 which is in contact with the cylindrical portion of the vessel 22.

Abstract: A lamp for automotive front lighting and a vehicle headlight comprising the lamp are described, as well as a method of manufacturing the lamp. The lamp 10 comprises a base 12 for mechanical and electrical connection to an automotive headlight 50. A burner 14 is fixed to the base 12 and comprises an enclosed transparent vessel 22. A first filament 34 is arranged within the vessel 22. A holding wire 30c is arranged within the vessel, and a baffle 40 is arranged proximate to the first filament 34 to partially shield light emitted from the first filament 34. The baffle 40 is fixed to the holding wire 30c. The transparent vessel 22 comprises a vessel wall including a cylindrical portion 24 surrounding the first filament 34. In order to obtain a lamp which may withstand vibration, the vessel wall comprises, within the cylindrical portion 24, a deformed material portion 38 which contacts the baffle 40 or the holding wire 30c. The deformed material portion 38 is shielded from the first filament 34 by the baffle 40.

Abstract: A lamp for automotive vehicle front lighting is described. The lamp 10 comprises a base 12 for mechanical and electrical connection to an automotive headlight 50 and a burner 14 fixed to the base 12. The burner 14 comprises an enclosed transparent vessel 22. A first and a second filament 34, 36 are arranged within the vessel 22. A baffle 40 is arranged proximate to the first filament 34 to shield the second filament 36 from the first filament 34. The baffle 40 is of concave shape and includes a bottom surface 41 and side surfaces 45 terminating in side edges 48. The baffle 40 further includes a front surface 43 arranged between the first and second filaments 34, 36 to shield the second filament 36 from light emitted from the first filament 34. The side edges 48 each comprise a central portion 54 extending, in side view, straight and in parallel to the longitudinal axis X. The straight central portions 54 have an axial length of at least 3.5 mm.

Abstract: A lamp assembly for the lamp assembly adapted for use in a substrate thermal processing chamber to heat the substrate to temperatures up to at least about 1100° C. is disclosed. In one embodiment, the lamp assembly comprises a bulb enclosing at least one radiation generating filament attached to a pair of leads, the bulb having an inner surface and an outer surface, a lamp base configured to receive the pair of leads and at least a portion of the bulb having a surface treatment adapted to reflect light away from the lamp base. In another embodiment, a sleeve covers the lamp base, which has a cross-sectional area less than about 1.2 times the cross-sectional area of the bulb.

Abstract: The invention relates to methods for generating radiation at resonance transitions of metal atoms in mixtures of inert gases and metal vapors that are excited by an arc electric discharge. The technical effect of the claimed invention is raising the efficacy and service life of radiation sources at metal atom resonance transitions, which are excited by a low-pressure arc discharge. The technical effect is achieved due to that, according to a method for generating radiation at resonance transitions of metal atoms in mixtures of inert gases and metal vapors, which method includes exciting mixtures of inert gases and metal vapors by a high-frequency alternating longitudinal electric discharge, a discharge is excited by essentially rectangular current pulses with an off-duty ratio not more than 2.0 and duration not exceeding the efficient life-time of resonance state of the radiating metal atom.

Abstract: Disclosed is a light guiding valve apparatus including a light valve, a two dimensional light emitting element array and an input side arranged to reduce light reflection for providing large area directional illumination from localized light emitting elements with low cross talk. A waveguide includes a stepped structure, in which the steps may include extraction features hidden to guided light propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Stray light falling onto a light input side of the waveguide is at least partially absorbed.

Abstract: Described embodiments include an incandescent lighting system and a method. A described system includes a gas filled and sealed glass envelope. The system includes at least two filaments enclosed within the glass envelope. Each filament of the at least two filaments is configured to generate light in response to a flow of electric current. The system includes a controller circuit configured to manage the at least two filaments in response to a filament management schedule. The filament management schedule includes managing the respective flow of electric current through each filament of the at least two filaments. In an embodiment, the schedule includes managing the respective flow of electric current through each filament of the at least two filaments so that not all of the at least two filaments generate light at any one time.

Abstract: Described embodiments include an incandescent lighting system and a method. A described system includes a gas filled and sealed glass envelope. The system includes a gas filled glass envelope. The system includes at least two filaments enclosed within the glass envelope. Each filament of the at least two filaments is configured to generate visible light in response to a flow of electric current. The system includes a sensor configured to detect an aspect of a filament of the at least two filaments and to generate a sensor signal indicative of the aspect. The system includes a controller circuit configured to manage the at least two filaments in response to a filament management schedule. The filament management schedule includes adjusting a flow of electric current through a filament of the at least two filaments in response to the sensor signal.

Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.

Abstract: A module is provided for irradiation of at least one substrate. The module includes an irradiation unit for irradiating the substrate with ultraviolet light, wherein the irradiation unit has a discharge lamp with an integrated reflector. A method is also provided for producing an irradiation module for irradiating a substrate using UV light, wherein the reflector is coated on the discharge lamp.

Abstract: An illuminator includes: a first light source and a second light source that are disposed substantially symmetrically with respect to an illumination optical axis, wherein each of the first and second light sources includes an arc tube, a first reflector disposed to surround part of the entire space around the optical axis of the arc tube, the first reflector reflecting the light emitted from the arc tube toward an object to be illuminated, and a second reflector disposed on the opposite side of the optical axis of the arc tube to the first reflector, the second reflector reflecting the light emitted from the arc tube toward the first reflector.

Abstract: An improved incandescent lamp and incandescent lighting system are disclosed, for projecting a beam of light with substantially improved energy efficiency. The incandescent lamp includes a pair of reflective ceramic filament supports for supporting one or more filaments in prescribed position(s) within an envelope while reflecting back substantially all visible and infrared light for incorporation into the projected beam or for absorption by the filament(s).

Abstract: Disclosed is a lamp, particularly for a vehicle headlight, comprising two spiral-wound filaments which are retained by three feeders within a bulb that is inserted into a base. The feeders are arranged on top of one another when the lamp is adequately oriented. A tail of the first spiral-wound filament is connected to a dimming cap, said tail being located at a distance from the base, while a tail of the second spiral-wound filament is connected to the central feeder, said tail being close to the base. The second filament tail that faces away and is located at a distance from the base is connected to the upper feeder. According to the invention, the lower feeder is connected to the dimming cap by means of an end, some sections of which are angled away from a longitudinal axis of the lamp.

Abstract: The invention relates to a dipping cap comprising a filament for a dual-filament lamp. The dimension between an outlet of an outgoing section of the filament, on the side of the base, and the point on the outgoing section of the filament, arranged opposite the outgoing section of the filament on the side of the base and welded to the dipping cap, measures more than approximately 5.2 mm and less than 9.7 mm, and the dimension between the outlet of the outgoing section of the filament, on the side of the base, and the front surface of the dipping cap, which is adjacent to the outgoing section of the filament, welded to the dipping cap, measures more than approximately 5.9 mm and less than 11.9 mm.

Abstract: A lamp (10), which can be used in rapid thermal processing (RTP), has a lamp envelope (12) arrayed along a longitudinal axis (14) and has a top (16) and a bottom (18). A first coiled-coil filament (20) having a first lead-in (20a) and a second coiled-coil filament (22) having a second lead-in (22a), are parallelly arrayed to each other and to the longitudinal axis (14) within the envelope (12). A serial connector (24) joins the first and second filaments; and an electrically insulating support (26) is positioned near the bottom (18) of the lamp envelope (12). The first lead-in (20a), the second lead-in (22a) and at least a portion (24a) of the serial connector (24) are sealed within the insulating support 26 whereby the first and second lead-ins (20a, 22a) and the at least a portion (24a) of the serial connector (24) provide the only support for the first and second filaments (20, 22).

Abstract: A light source device includes first and second electrodes, an arc tube having a main body section having a discharge space in which the first and second electrodes are disposed with a distance and a sealing section disposed on each of the both ends of the main body section, a primary reflecting mirror disposed on the side of the first electrode, a secondary reflecting mirror disposed on the side of the second electrode, and a current drive device that generates an alternating current for causing the discharge between the first and second electrodes, and power control by controlling the alternating current so that supplying energy in an anodic term of the first electrode becomes smaller than supplying energy in a cathode term.

Abstract: The invention relates to a dipping cap comprising a filament for a dual-filament lamp. The dimension between an outlet of an outgoing section of the filament, on the side of the base, and the point on the outgoing section of the filament, arranged opposite the outgoing section of the filament on the side of the base and welded to the dipping cap, measures more than approximately 5.2 mm and less than 9.7 mm, and the dimension between the outlet of the outgoing section of the filament, on the side of the base, and the front surface of the dipping cap, which is adjacent to the outgoing section of the filament, welded to the dipping cap, measures more than approximately 5.9 mm and less than 11.9 mm.

Abstract: A backlight unit that converts ultraviolet light emitted from light-emitting lamps into visible light is disclosed. The backlight unit also reflects the visible light, thus achieving improved luminance. The backlight unit includes a plurality of light-emitting lamps arranged substantially in parallel, an outer case that fixes and supports the light-emitting lamps, and a reflection sheet disposed within the outer case and containing a fluorescent material that converts ultraviolet light into visible light and reflects the visible light.

Abstract: A 3-way reflector lamp includes a parabolic reflector (3) mounted on a 3-way lamp base having screw shell, a center contact and an intermediate contact. The reflector has its focus on its optical axis proximal end and extends in the distal direction. A first filament is connected to the screw shell and center contact, whereby light from the first filament is collimated by into a spotlight beam, and a second filament on the optical axis is spaced in the distal direction from the first filament and connected to the screw shell and an intermediate ring contact, whereby light from the energized second filament is diffused into a floodlight beam, and light from both energized filaments produces a spotlight beam within the floodlight beam.

Abstract: A lamp radiates visible light and infrared light. The lamp bulb of the lamp includes at least a first region which is at least partly permeable to infrared light, and at least partly impermeable to visible light. At least a second region of the bulb is wholly or partly permeable at least to visible light.

Abstract: The invention relates to a reflector lamp which comprises a reflector body (13) with a concave reflective part; an electric lamp (15) comprising a gastight lamp vessel with at least one end portion (18), an electric element (17) arranged in the lamp vessel, and a current conductor (19) extending through the end portion to the electric element; a support body (23) comprising reflector fastening means (30, 27) for fastening the support body to the reflector body, mechanical lamp vessel fastening means (43, 46) for fastening the support body to the end portion of the lamp vessel, and housing fastening means for fastening the support body inside the housing (2).

Abstract: An incandescent lamp comprises at least four linear, helically-wound filament sections arranged with their longitudinal axes substantially parallel with each other and including a first filament section located along the longitudinal axis of the lamp with the remaining filament sections arranged substantially symmetrically around the first filament section.

Abstract: A light source bulb in an automotive headlamp having a lamp chamber defined by a lamp housing and a lens, where the lamp chamber includes a reflector and the light source bulb arranged therein. The reflector includes a reflecting surface constituted by a complex reflecting surface. The light source bulb includes a high-beam filament arranged obliquely below and behind with respect to a low-beam filament. When lit, high and low beam distribution patterns are formed by entire-surface reflection light distribution control of the reflecting surface. The light source bulb is used for right traffic and for left traffic. A second support wire is, in a side view of said light source bulb, bent to rearward of the rear end of said high-beam filament and positioned above the lower end of said low-beam filament.

Abstract: A motor vehicle has left and right hand headlights, each with a reflector having a complex surface with a lamp fitted within the reflector. Each lamp has a dipped or passing beam filament and a main beam filament. The position of the main beam filament is defined by its angular position with respect to a position of origin vertically below the main axis of the lamp, on a circle centered on the main axis, the main beam filament being oriented positively in the trigonometric direction looking forward along the main axis. The angular position of each main beam filament is in the range between −90° and +90°, and is different for each headlight.

Abstract: An improvement to the current-carrying components of a lamp includes two filaments connected to two different electrodes and one common electrode, and a switch for directing current through the secondary filament upon the failure of the primary filament. Normally, the current flows through the primary filament. The switch in one embodiment is a wire that does not conduct when the primary filament is operational but conducts on the failure of the primary filament to shunt the current to the secondary filament. The wire is an oxide metal wrapped around two of the three electrodes inside the glass envelop of the lamp. When the primary filament fails, the open circuit voltage breaks across the oxide layer to weld the wire to the electrodes and bypass the primary filament.

Abstract: A head lamp apparatus for a vehicle comprises a lamp housing mounted to a front portion of a vehicle body, a head lamp bulb disposed inside the lamp housing and adapted to radiate a light, a reflector for reflecting an irradiation light from the head lamp bulb in a direction forward of the vehicle body, and a position bulb disposed in front of the head lamp bulb inside the lamp housing.

Abstract: There is provided a lamp unit for light radiating type heating device which allows efficient cooling of the lamps, and the temperature increase of a semiconductor wafer irradiated with the lamp unit is faster than in the prior art without the need of a complicated and large cooling structure.

Abstract: A portable lamp with adjustment device to obtain different emitted light cones includes a light source received within a concave reflector. The light source includes at least two separately switchable incandescent filaments operatively connected to a power source, which are arranged within the light source to generate a desired light cone. By way of example, according to the invention, a filament intended to generate a small angled light cone, i.e. for far distance illumination, draws greater power from the power source than a filament intended to generate a wide angled light cone. To this end, each of the filaments has different illuminous efficiencies. An additional laser light source, electronic flash unit controlled by the light source may also be provided.

Abstract: There is provided a lamp unit for light radiating type heating device which allows efficient cooling of the lamps, and the temperature increase of a semiconductor wafer irradiated with the lamp unit is faster than in the prior art without the need of a complicated and large cooling structure.

Abstract: A multiple element lamp includes an enclosure mounted on a base with a plurality of lighting elements mounted independently within the enclosure. The lighting elements are electrically connected to a control circuit in the base which selectively supplies power to the individual lighting elements. The control circuit will disconnect a lighting element upon the detection of a decrease in lighting efficiency of the element, and turn on another of the plurality of elements.

Abstract: A light source comprises an array of contiguous transparent blocks, each of which contains a light emitter such as a cold cathode fluorescent tube. The blocks have a transparent front surface which may be optically diffusing, the other surfaces being coated with a thin optically reflective layer so that each block acts as a light guide. The tubes are independently controllable, for instance so as to simulate a moving light source which may be controlled so as to track the position of an observer of a 3D display.

Abstract: An apparatus for producing a three-dimensional object by successive solidification of layers of a solidifiable material (7) at places corresponding to the respective cross-section of the object by means of radiation is provided whereby the apparatus comprises a support (4) for supporting the object (6) to be formed, a coating device (12) for applying layers of the solidifiable material (7) onto the support (4) or a previously solidified layer, a solidifying device (14) for solidifying the layers of the material (7) at places corresponding to the respective cross-section of the object and a heating apparatus (8) disposed above the support (4) in operational position for heating the solidifiable material (7), the heating apparatus (8) comprising at least one straight radiant heater (81) with a varying heating power along its length.

Abstract: To prolong the life of a vehicle light bulb by securing the legs of the dipped beam filament by forming a hole in cupped shield, fixing one leg directly to common lead by passing this leg through the hole, and fixing the other leg directly to lead. If the shield vibrates as shown by circled arrows 2 and 2, this vibration is not transmitted to the dipped beam filament. Accordingly, the life of dipped beam filament can be further prolonged.

Abstract: The invention concerns an electrical incandescent lamp with a low-beam cap, articularly a two-filament halogen incandescent lamp and a production process for such a lamp, as well as a low-beam cap. Low-beam screening cap (12) has an opening (14), through which one end (6a) of low-beam filament (6) is threaded. This filament end (6a) is welded to the back side of low-beam screening cap (12) or to a current lead wire (8a), which is attached by a projection welding to the back side of low-beam screening cap (12). The fastening of low-beam filament (6) according to the invention makes possible materials savings in the case of a low-beam screening cap (12) and lower cost lamp manufacture.

Abstract: In an automobile lamp bulb, a shield is attached firmly to a common conductor by an improved fixing method. Dents are formed in one surface of a shield to form projections in the other surface of the same and a cut is formed in the shield. Portions of the shield defined by the cut are raised to form lugs, and projections are formed, respectively, on the lugs. A projection is formed in each lug which corresponds to the dents, but project in opposite directions. The projections of the shield are welded by projection welding to the common conductor to join the shield firmly to the common conductor. Therefore, an inexpensive rough service automobile lamp bulb is provided. In another embodiment, a portion of a round common conductor is flattened to form a flat portion. A shield is positioned on and welded to the flat portion of the common conductor. Since the shield is positioned on and welded to the common conductor in surface contact, the amplitude of vibration of the shield can effectively be suppressed.

Abstract: An igniter has an inner electrode extending with a forward and rear ceramic sleeve. The rear end of the forward sleeve projects as a sliding fit within the forward end of the rear sleeve. A nickel alloy flange with a flexible shoulder has an inner neck brazed to a nickel layer on the outside of the rear sleeve. An outer collar on the flange is welded to the inside of the outer electrode to form a seal between the outside of the sleeve and the inside of the outer electrode. A metal cap is brazed to a nickel layer at the rear end of the rear sleeve and is welded to the inner electrode to seal the rear end of the rear sleeve.

Abstract: A reflector incandescent lamp for high-voltage operation has substantially xially parallel radiant body sections and a reflector, whose facets are formed by approximately axially parallel cylindrical segments.

Abstract: The present invention relates to a spark plug electrode (14) of a first material having good thermal conductivity having a core (24) of a second material having good corrosion resistance. The first material may be copper, or a copper alloy, and the second material may be nickel, a nickel alloy, silver, or a silver alloy. The electrode (14) may be produced by a method comprising the steps of: providing a tubular cup (28) formed of the first material; positioning a billet (34) of the second material within the cup (28); and extruding the assembled cup and billet.

Abstract: In a spark plug having a center electrode and an outer electrode, at least one of which is made of a nickel-alloyed clad and a thermally conductive copper-alloyed core embedded in the nickel-alloyed clad, the copper-alloyed core includes an additive metal which forms a supersaturated solid solution with a copper metal in which the additive metal or an intermetallic compound is precipitated from the copper phase, and substantially evenly dispersed.

Abstract: The invention disclosed relates a bulb for use with vehicular lighting equipment and adapted for use therein. It comprises a glass bulb member having a multi-layered color layer, a non-color portion and light shield layer located thereon, a stem, a plurality of inner leads, a pair of filaments, a metallic shield member, a plug, etc. As combined with a reflector in vehicular lighting equipment, the bulb enables change of its beam in orientation and in color by selective operation of the filaments.

Abstract: The present invention includes a spark plug with a copper cored ground electrode wherein the copper core has a cross-sectional area of about 1.6 mm.sup.2 to about 3.0 mm.sup.2 and the remainder of the electrode is made from a nickel alloy sheath. The open end copper cored ground electrode is resistance welded to the steel shell using a light welding force of about 100 lbs. coupled with a low welding energy to eliminate voids and embrittlement in the copper core adjacent to the weld interface.

Abstract: A single-ended halogen incandescent projector lamp having a reflector mount fixed to the lamp frame remote from a bi-planar filament array. The lamp has a lamp envelope with a pinch seal at one end and a fused tip portion at the other. The lamp frame has a pair of frame conductors extending longitudinally in the lamp vessel, a pair of transverse quartz bridges between which the filament array is supported, and a frame center support extending into the fused tip portion from the bridge closest to the fused tip portion. The reflector mount is a single length of wire having a center portion coiled about and slidable along the frame center support, and a pair of legs extending therefrom to which the reflector is secured. The coiled portion is welded to the top center support to hold the reflector in position. Damage to the filament during lamp assembly is avoided since the reflector mount is fixed to the top center support instead of the frame conductors.

Abstract: In an outer electrode, a rear end of which is securely connected to a metallic shell of a spark plug by means of welding to form a spark gap between a front end of the outer electrode and a firing tip of a center electrode which is concentrically placed within the metallic shell through an insulator, a middle core which is provided which is made of copper, and the middle core is clad by a heat and spark-erosion resistant metal. A centermost core is clad by the middle core. The centermost core is made of a similar metal to the metallic shell, and rear end of the centermost core is welded to the metallic shell so as to reinforce a welding portion between the metallic shell and the outer electrode.