Abstract: The present invention is directed to a shaped plastic roof tile preferably one shaped like a slate tile. The tile is constructed of the combination of a thermoplastic, preferably one or more polyolefin polymers, and a chlorine containing polymer in an amount to provide a final chlorine content to the tile of between 1% and 65% by weight. The polyolefin polymer is preferably a combination of polyethylene and polypropylene derived from recycled material.

Abstract: A simple and cost-efficient decorative post covering. The decorative post covering has two L-shaped members that are sized and shaped to fit around a post. The decorative post cover includes an attachment mechanism for attaching the first and second members together and around the post. The attachment mechanism is formed integral to the L-shaped members. The attachment mechanism includes a lip end and a receiving end on each of the first and second members. The lip end of the first member is connected to the receiving end of the second member and the lip end of the second member is connected to the receiving end of the first member. The first and second members are identical and therefore interchangeable. The first and second members have longitudinal scalloped grooves molded therein to increased the rigidity of members and give the appearance of a pillar or column.

Abstract: A building block for constructing masonry block walls includes a concrete block formed with first, second and third spaced parallel rectangular side walls, where the second side wall is intermediate the first and third side walls. First and second vertical end cross webs connect the first and second side walls; and a notch is formed in the upper surface of each of these vertical end cross webs. First and second spaced intermediate vertical cross webs are located in planes between the planes of the end cross webs and connect the second and third side walls. These intermediate cross webs each also have a notch extending downwardly from the top thereof. A first insulating core is dimensioned to fill the space between the first and second side walls and first and second end cross webs. Ears or protrusions extend outwardly from the insulating core to fit into the notches in the end cross webs.

Abstract: An assembly of panels and jointing elements, in particular for the technical field of building, wherein each panel (11, 12), taken in section, comprises an alveolar structure, determined by a plurality of ribs (14) and arranged between two main outside surfaces (10, 28, 29), extensions (15, 16) obtained at opposed ends of each panel (11, 12), and a jointing element (13, 113) adapted to receive an extension (15, 16) of each of two adjacent panels (11, 12) firmly engaging them, wherein both each extension (15, 16) and the jointing element (13, 113) are provided with reciprocally engaged inclined surfaces (20, 21, 24, 25) facing inwards and facing each other, and wherein the jointing element (13) is U-shaped and is provided with a pressing element (19) that centrally extends inside it and arranges in wedged engagement between outside facing walls (17, 18) of the two extensions (15, 16).

Abstract: To prevent the roof covering layer(s) of a substantially flat roof from being blown up in stormy conditions a mortar is put thereon, which comprises a granulated mineral wool, a hydraulic binder and water. Preferably the roof surface to be ballasted is divided—by placing joint elements thereon—into panels. Advantageously rockwool waste originating from the horticulture and glass fibre wool waste may be used as the mineral wool component.

Abstract: A method and apparatus for processing mail is provided. Mail is placed into an input bin having a conveyor that conveys the mail towards a feeder. The feeder serially feeds the envelopes by engaging the lead envelope in the stack of mail and displacing the lead envelope transverse the stack of mail. The mail is fed into a shuttle that vertically displaces the envelopes to position the envelopes for entering a justifier. The justifier justifies the top edge of the envelopes and conveys the envelopes to a cutter that severs the top edge of the envelopes. A transport conveys the envelopes from the top cutter to an extractor. The extractor opens the edge-severed mail and presents the contents of the envelopes to an operator who manually extracts the contents. The transport conveys the empty envelopes from the extractor to a verifier that verifies that all of the contents have been removed from the envelope before the envelope is discarded.

Abstract: A machine for packaging a mattress in a sheet, comprising horizontal supporting and receiving mattress surfaces, guides for guiding the sheet on a vertical plane, so that by moving the mattress in the advancement direction from the supporting surface toward the receiving surface the sheet is arranged over and under the mattress, a device for joining and cutting the sheet upstream of the mattress and for forming a bag which wraps around the mattress, sheet unwinding assemblies comprising two rollers movable along the receiving surface with a return stroke, the rollers being articulated to rotate between alignment and parallel positions in which they are perpendicular or parallel to the advancement direction and to the sides of the mattress, and actuators for actuating the rollers.

Abstract: A cylindrical segment having a longitudinal axis has a helical edge which serves as a static flap folding edge for a carton in translatory motion with respect to the cylindrical segment. The cylindrical segment is reciprocally rotatable about an axis such that when the cylindrical segment rotates the helical edge progressively engages and folds a flap of a carton disposed at the helical edge.

Abstract: A surgical spear includes a cut sponge element that has been processed to render it at least substantially free from particulates and other debris; an eye spear comprised of an essentially particulate-free sponge element is uniquely suited for LASIK surgery. In most instances the surgical spear will be enclosed in a packaging component, which may or may not be fabricated from a water-permeable material and may or may not be left unsealed in the packaging step.

Abstract: For assembling mail items, a type of envelope is selected from different types. Another station is accordingly set and a flat object is packaged in an envelope of the selected type. Prior to the assembly of a series of mail items, a set of basic finishing instructions applying to said series is activated. This set contains a first and a second set of instructions, each for selecting a first respectively second one of the different types of envelopes and with an instruction for an associated first respectively second setting of the other station, and a selection criterion for selecting, per individual mail item, one of the sets of instructions. Thus, within the framework of a preset set of basic finishing instructions, another one of the available types of envelope can simply be selected per mail item to be assembled individually.

Abstract: A packaging device is provided with a feed unit for a highly stretchable polyethylene-based plastic film which during use is able to generate and maintain a high number of electric charges on its surface. A vertically movable head having on its lower end a gripping surface with a very smooth, mirror-like gripping surface, is then lowered to have its gripping surface engaged with the leading end of the film which overlies and is supported on a planar supporting surface. The smooth gripping surface of the head adheres cohesively by electrostatic molecular attraction to the film, the like, which is to be covered by the film. The head then descends severing the film from the supply thereof and securing the edge of the film to the edge of the container.

Abstract: A forming roller for manufacturing molded bodies with the rotary die method comprises a surface which is roughened at least in the region of the forming roller webs. By way of the roughening of the forming roller webs the adhesive friction for the material tapes from which the molded bodies are manufactured is increased. The roughness of the surface parts of the forming roller is advantageously produced by the processing of the surface with a blast means.

Abstract: Measuring apparatus in the form of a fitting bridle (10) for use in making equine tack includes a strap of adjustable length, the strap being made up of a first strap member and a second strap member joined by connection means (34, 44) whereby the position of the first or second strap member within the connection means (34, 44) may be adjusted to thereby adjust the length of the strap. The strap may form a cheek piece, brow band, throat lash or part of a nose band of the fitting bridle.

Abstract: An arrangement for cooling the engine of a harvesting vehicle includes a circular sieve or screen mounted for rotation about a fore-and-aft axis and through which air is drawn by a fan which discharges the air through a cooling device. A cleaner in the form of a brush includes a cylindrical bristle arrangement mounted for rotating about an axis arranged parallel to an inlet side of the sieve with the bristles projecting through sieve openings. Located on the outlet side of the sieve is a suction device that acts to carry away contaminants poked through the sieve by the bristles of the brush. A further embodiment of the invention includes a second suction device mounted adjacent the inlet side of the sieve in trailing relationship to the brush arrangement so as to be able to carry away contaminants loosened by the brush arrangement but still clinging to the inlet side of the sieve.

Abstract: A filter cartridge is made of an accordion fold pack folded in a zigzag-shape. At the end faces (4) of the accordion fold pack, running parallel to the folds, provision is made for the closing elements (5) which include stiffening strips (6), partially covering the accordion fold pack (2), at least on its discharge side, and sealing elements (7) integrally connected to the stiffening strips (6).

Abstract: The invention describes a hydraulic reel drive wherein the reel motor is driven by a hydraulic pump, which is adjustable in a continuous manner and operates therewith in a closed oil circulating system. The advantage of this arrangement is that the reel always rotates uniformly independently of the instantaneous load thereon. Another advantage thereof is that by using a hydraulic pump, which is adjustable in a continuous manner, only that amount of oil is ever circulated as is required to drive the reel at a predetermined rotational speed.

Abstract: A device for starting a work station (2) of a cheese-producing textile machine, in particular after a batch change, wherein the work station (2) has a creel (18) for rotatably holding a bobbin tube (34), a splicing device (13) for connecting yarn ends, and manipulating means (12, 24) for inserting the yarn ends into the splicing device (13). A yarn (28) connected with a feed bobbin (9) is placed into the splicing device (13) by means of a gripper tube (24). The winding station has a device (30) for cutting the yarn (28), and a device (26) for receiving the cut yarn (28). A special suction tube (1) makes possible the transfer of the cut yarn (28) to a second clamping and cutting device (23) arranged in the area of the creel (23).

Abstract: A single-sided ring spinning frame having spinning positions including draft parts and winding parts on a front side of the machine frame, and rows of cans arranged on a rear side of the machine frame. Each can has a plurality of sliver accommodating areas to accommodate a plurality of rows of sliver coils therein. Sliver guides are arranged above the cans. Therefore, the number of the cans is less than the number of spinning positions, and the height of the cans is selected so that an operator can easily handle the sliver in the can. Also, a method for supplying slivers to a single-sided ring spinning frame, and a sliver transfer device used in the method are also disclosed.

Abstract: The lightened bracelet with articulated metallic links comprises lateral links (4a, 4b) connected by two pins (3) or screws (6) and at least one row of central links articulated on two pins (3) or screws (6) connecting different lateral links. The central links comprise a tubular metallic envelope (1) in which is disposed at least one insert (2) of plastic material provided with two passages each receiving with low friction a pin (3) or a screw (6).

Abstract: Three structural components jointly constituting a single guide link of a silent chain, i.e.

Abstract: A gas turbine is provided with combustors having cooling passages formed in the wall of the combustors. The walls of the combustors are cooled by cooling fluid flowing through the cooling passages. Steam generated by a waste heat recovery boiler is supplied to the cooling passages as cooling fluid during the normal operation of the gas turbine. During start up and shut down operation of the gas turbine, pressurized air from the gas turbine compressor is supplied to the cooling passage as cooling fluid. Since pressurized air from the gas turbine compressor is used for cooling fluid for the combustors during start up and shut down operations, a separate auxiliary boiler is not required for supplying cooling steam to the combustor during start up and shut down operation.

Abstract: A combined cycle power plant having a gas turbine plant and a steam turbine plant combined together is disclosed. Steam is used for cooling a high-temperature portion (5) to be cooled around the combustor (4) of the gas turbine (2). The power plant has an air duct (9), connected to a steam path (7) for supplying steam for cooling the high-temperature portion (5), for cooling this portion using air if the steam for cooling is insufficient, typically when the plant is activated or stopped, and the air duct includes a device for boosting the air to have a pressure higher than that inside a combustor (4) of the power plant. Accordingly, the combustor and attached piping arrangement can be protected from burning and the power plant can be safely and reliably operated for a long time.

Abstract: A gas turbine and steam turbine installation has a waste-heat steam generator whose heating surfaces are connected into the water/steam cycle of the steam turbine. A gasification device is connected upstream of the gas turbine in order to provide an integrated gasification of a fossil fuel. Reliable operation of a saturator which is connected into a fuel line is ensured independently of the operating condition of the gasification device. For this purpose, a saturator-water heat exchanger connected with its secondary side into the saturator cycle is supplied, on its primary side, with feed water extracted from the water/steam cycle of the steam turbine. Thus it is possible to heat the feed water cooled in the saturator-water heat exchanger through the use of a partial flow of compressed air, and it is possible to supply the partial flow of compressed air to an air separation unit connected upstream of the gasification device.

Abstract: A gas turbine comprises a compressor for compressing a gas supplied therein and discharging the compressed gas, a combustor in which the discharged gas from the compressor and a fuel are combusted, a turbine to be driven by a combustion gas from the combustor, and an injection unit which injects water into the gas to be supplied to the compressor, thereby lowering the temperature of the gas to be introduced into the compressor than the atmospheric temperature, and causing water droplets having been injected in the gas and within the compressor to be vaporized while flowing down therein, wherein the quantity of water spray injection is controlled while monitoring operational conditions of the gas turbine.

Abstract: A device for controlling fuel pressure and delivery as necessary for the operation of the servovalves of an aircraft engine is disposed downstream of a fuel injector feed unit of the engine. The device comprises a chamber maintained at the servovalve feed pressure by the movement of a closure member to vary the opening of a port of the chamber. The closure member moves under the action of opposing forces comprising inter alia a force in the opening direction proportional to the servovalve feed pressure. An equilibrium position of the closure member is a function of pressure resulting from the engine speed. An injector delivery control loop is therefore isolated from a servovalve pressure and delivery control loop.

Abstract: The gas turbine fuel gas filling apparatus comprises a fuel main valve, a fuel valve, an inert gas purge valve, and a pressure detector for detecting a pressure in the fuel line. The fuel main valve is gradually opened, and fixed to a valve opening at a time when a predetermined first pressure condition is established. Pressure is measured after lapse of a predetermined time. The fuel main valve is gradually opened until a second pressure condition is established. Pressure is measured upon a completion of gas-filling. With establishment of a third pressure condition, the inert purge relief valve is closed. With establishment of a fourth pressure condition, the fuel main valve is fully opened.

Abstract: A controller controls an air-fuel ratio of an engine to maintain the oxygen storage amount of a catalyst provided in an exhaust passage at a predetermined amount. At this time, the controller first estimates the initial value of the oxygen storage amount based on the catalyst temperature on engine startup, and then computes an oxygen storage characteristic using this estimated initial value. In this way, the oxygen storage amount can be precisely computed even immediately after engine startup, and the conversion efficiency of the catalyst is maintained at a high level.

Abstract: A controller computes an oxygen storage amount of a catalyst based on the characteristics of an exhaust flowing into the catalyst, and controls the air-fuel ratio of an engine so that the oxygen storage amount of the catalyst is a target value. When it is determined that the engine starts from the warmed-up state when the engine starts, the air-fuel ratio of the engine is controlled to rich until the exhaust flowing out of the catalyst becomes rich. In this way, all the oxygen stored by the catalyst is first released, the NOx purification performance of the catalyst is maintained, and the NOx release amount immediately after engine startup is suppressed.

Abstract: A drive device comprising a closed hydraulic circuit which has a hydraulic drive adapted to be actuated by hydraulic medium and has a hydraulic pump responsible for the supply and removal of the hydraulic medium to and from the hydraulic drive. For the operation of the hydraulic pump an electric motor is provided. The activation of the hydraulic drive is controlled by the operational state of the hydraulic pump.

Abstract: A device for limiting the supercharger speed which makes do without a speed sensor or an atmospheric pressure sensor has a bandpass filter which filters out a spectral component from the output signal of a boost pressure sensor arranged in the induction pipe of the engine, the spectral component appearing in the signal spectrum of the boost pressure sensor when the air column in the induction pipe is set into a vibration which develops when the compressor of the turbocharger rotates at the maximum permissible speed.

Abstract: Applicant's preferred embodiment utilizes municipal wastewater effluent to replenish a depleted geothermal field. Condensate produced by expanding steam produced in the geothermal field through a steam turbine-generator may be pooled with cooked water collected from said field, and then directed through a penstock from a higher elevation to a lower elevation where further energy is extracted through a traditional hydroelectric turbine-generator. The cooked water and condensate may be treated to produce potable water and/or distributed for public consumption either before or after being directed to the hydroelectric turbine-generator. The effluent is pumped up to the geothermal field during off-peak periods of electric consumption, and the hydroelectric generation is accomplished during periods of peak electric demand. A fraction of the effluent may be used as cooling water for the steam turbine-generator and its associated condenser before injection into the geothermal field.

Abstract: The invention concerns a method and a device for operating a heating and cooling machine that functions on the basis of a regenerative gas cyclic process, in particular a Vuilleumier heat pump, having a burner (34) as the source of the thermal driving, in which, to increase its efficiency or to maximize the output number of the heating and cooling machine, the combustion air conveyed to the burner (34) is preheated in the heat exchange with the exhaust gases. It is proposed that, for increasing the output performance of the heating and cooling machine, the preheating of the combustion air is forestalled at least partially, whereas in response to a simultaneous increase of the burner output, the hot exhaust-gas mass-flow is conveyed to an exhaust-gas-water heat-exchanger (50).

Abstract: A gas turbine plant comprises an air compressor, gas turbine turbine including at least one high temperature section, a driven equipment, which are operatively connected in series, a gas turbine combustor arranged between the air compressor and the gas turbine, a fuel system disposed for supplying a fuel to the gas turbine combustor, and a heat exchange section for heating the fuel from the fuel by means of a high pressure air as a heating medium fed from the air compressor.

Abstract: A gas turbine combustor, in which plural pre-mixers that inject fuel into swirling air passages are arranged to surround a pilot burner, and a pilot flame, guided by a pilot cone in the shape of a flaring pipe and provided at the rear end of the pilot burner, is mixed with a pre-mixture blown out from the pre-mixers to obtain a combustion gas, comprising flame-stabilizing means. The flame-stabilizing means lower the disturbance in a region where the pre-mixture and the pilot flame are mixed or stabilize the pilot flame, so that the flame generated by igniting the pre-mixture with the pilot flame is stabilized. By stabilizing the flame, combustion with a leaner air-fuel ratio is possible, and thereby the amount of NOx can be decreased.

Abstract: In a refrigerating/air-conditioning apparatus including operating/controlling units such as outdoor units, indoor units and control devices for individually or collectively controlling the driving of the outdoor units and the indoor units, each operating/controlling unit being equipped with a controller for controlling the driving of the operating/controlling unit, the controller having a rewritable memory for storing a control program, control parameter data, control data, etc.

Abstract: In a freezing cycle apparatus that switches between a cooling mode and a heating mode, wherein a low-pressure refrigerant is evaporated in an evaporator 18 for cooling the air during a cooling mode and a hot gas refrigerant is introduced from the discharge side of a compressor 10 directly into the evaporator 18. A variable displacement type compressor capable of varying the displacement is used as the compressor 10. The displacement of the compressor 10 is controlled such that the refrigerant flow rate in the cooling or heating cycle is a predetermined target flow rate during the cooling and the heating mode.

Abstract: An apparatus for heating and cooling includes a solar collector for transferring heat energy from incident solar rays to a liquid refrigerant material thereby changing a first portion to a gaseous state. An eductor-venturi reduces a pressure of the gaseous refrigerant material and a condenser removes the heat energy thereby changing the refrigerant material back to the liquid state. A heat exchanger associated with the condenser receives the heat energy removed from the refrigerant material. A float evaporator mounted in a cold chamber transfers heat energy from the atmosphere to the liquid refrigerant material thereby changing a second portion to the gaseous state and cooling the cold chamber atmosphere. A float actuated valve connected to the float evaporator is responsive to a level of the liquid refrigerant material in the evaporator for regulating a flow of the liquid refrigerant material into the evaporator.

Abstract: An automotive climate control system is disclosed. As long as an ignition switch is off, a bypass (14) is closed (in this state, a ratio between warm air and cool air is a maximum when the automotive climate control system is activated.), the blowout is set to defrost mode and the introduced air is set to external air mode regardless of the preceding modes of blowout and introduced air (when the ignition switch is on). As a result, the refrigerant leaking from an evaporator (12) flows to an external air inlet (23) smaller in air resistance. Even in the case where the ignition switch is off, therefore, the leaking refrigerant is prevented from flowing into the cabin.

Abstract: An adsorbent unit for a refrigerant accumulator having a housing with a bottom wall and a side wall and a U-shaped pipe with a return bend adjacent the bottom wall and with first and second pipe portions extending from the return bend along the side wall, and a filter body extending outwardly from the return bend, the adsorbent unit including a porous adsorbent container, adsorbent in the container, first and second end portions on the container, a first tab extending outwardly from the first end portion of the container, an elongated slot in the first tab mounting it on the first and second pipe portions, a second tab extending outwardly from the second end portion of the container, and an aperture on the second tab mounting it on the filter body. A double adsorbent container adsorbent unit having elongated slots on tabs at the outer ends thereof for mounting about the first and second pipe portions.

Abstract: A silicon surface oxidation device utilizes a steam generator in which heated water is barely in contact with the members of the device, steam with no contamination is efficiently generated, and the silicon surface can be oxidized through relatively large thickness by using a steam oxidation method which is simple and high in safety. The steam generator has a feed port for pure water which flows along a surface in a chamber, an oscillator for oscillating a microwave toward the surface, a steam exit port for sending out the steam of the pure water generated from the surface by the microwave, and a discharge port for the pure water flowing along the surface. A heating furnace is connected to the steam exit port, and silicon placed in the heating furnace is oxidized by the steam generated by the microwave.

Abstract: A circular knitting machine for hosiery, with a device for producing tubular items closed at an axial end, and relative method. The machine has a diverter accommodated inside the needle cylinder disengaged from the rotation of the needle cylinder about its own axis with respect to the needle actuation cams and to the lowering sinker actuation cams. The diverter has a profile which protrudes from an internal region of the needle cylinder gradually toward the wall of the needle cylinder. The profile is engaged by an end portion of the item lying inside the needle cylinder between two needles mutually angularly spaced around the axis of the needle cylinder in order to achieve sliding of the item portion along the profile following rotation of the needle cylinder with respect to the diverter. The machine has sinkers for retaining the item portion against the profile during its sliding.

Abstract: A thread and a fabric are provided which are capable of being dyed to have a desired color and are formed of a metal-plated yarn excellent in antibacterial and electro-magnetic shielding properties. The thread for achieving this object is a composite thread (1) consisting of a chain stitch yarn (3) formed of a dyeable yarn and a metal-plated yarn (2) inserted as a core yarn into the chain stitch yarn (3). A fabric or a weft-knit product formed of the composite yarn (1) is excellent in antibacterial and electro-magnetic shielding properties and capable of having a favorable appearance of desired color. If the metal-plated yarn is directly arranged in the warp-knit fabric, the metal-plated yarn (51, 52, 53, 54) is preferably inserted to be invisible to a human eye from the surface of the warp-knit fabric.

Abstract: A lock, in particular a hoop or cable lock, having a lock bolt which can be locked in place in a lock bolt recess of a lock housing, with the lock bolt being loaded in the locked state of the lock by a pad element in the direction of its unlocked position via its end face.

Abstract: Determining of the starting and end positions of the machining programme of a gear making machine with respect to the axial position of the workpiece (11, 18) by means of a laser light line (14) projected at right angles to the workpiece axis, the position of which light line relative to the reference point of the tool (5, 17) is known. By mutual displacement parallel to the workpiece axis, the light line (14) and one or both of the workpiece end faces (16) are brought to coincide. The axial positions thus obtained are transmitted to the machine control system. The determining of the axial tool position takes place analogously by the projection of a laser light line onto the circumference surface of the tool (5, 17) at right angles to the tool axis.

Abstract: The present invention intends to provide a manufacturing method of an irregular-section tubular body in which a manufacturing process is simplified, and complexing and large-sizing of an equipment, and increase of an equipment cost are avoided.

Abstract: A pipe shaping method forms a narrow neck at one end of a workpiece in the form of an elliptical pipe having a cross sectional shape elongated in a predetermined elongating direction, with a roller.

Abstract: A C-type frame is movable in a direction in which the C-type frame is adjacent to and away from a workpiece having an outer panel and an inner panel assembled with each other. After the C-type frame is advanced and a pre-hemming punch is advanced by a swing cylinder provided at the C-type frame, a hemming die is raised by a lifter hydraulic cylinder provided on a lower portion of the C-type frame and a flange of the outer panel is provisionally hemmed. Then, after retreat of the pre-hemming punch following lowering of the hemming die, the hemming die is raised again and final hemming is conducted between the hemming die and the hemming punch.

Abstract: A metal sheet having a pair of thin portions on respective marginal edges thereof which are joined to a remaining portion of the metal sheet via respective corners is centered by positioning the center between the corners as the center of the metal sheet. Then, elements are blanked out of the metal sheet. The elements remain joined to the metal sheet by respective connectors which are formed in the respective thin portions of the metal sheet, the bodies having respective lower edges formed in the respective thin portions of the metal sheet. The elements are separated from the metal sheet by cutting off the connectors along the lower edges of the bodies.

Abstract: Process for manufacturing cold formed shaped packaging having at least one recess made from a metal-plastic laminate 20. Examples of such shaped forms of packaging are the base parts of push-through packs or blister packs. The process is such that the laminate 20 is held between a retaining tool 5 and a die 1. The die 1 exhibits at least one opening 8 and a stamping tool 6 is driven into the die opening 8 causing the laminate to be shape-formed into the said packaging and, correspondingly, exhibiting one or more recesses. The die 1 and the retaining tool 5 exhibit facing edge regions 11, 12, and within the edge region 11 the die 1 exhibits a shoulder region 13 that surrounds the die opening 8 or openings 8. The surface of the shoulder region 13 lies 0.01 to 10 mm lower than the surface of the edge region 11 of the die 1.

Abstract: An improved structure of a gas sensor is provided which may be employed in an oxygen measuring device of an air-fuel ratio control system measuring an oxygen content in exhaust gasses of an internal combustion engine of automotive vehicles. The gas sensor includes a sensing unit which is disposed in a housing and has defined in an end portion thereof a reference gas chamber to be filed with a reference gas used in determining a given gas component content in gasses, a metallic cover installed on the housing to cover the other end portion of the sensing unit; and a cylindrical insulation porcelain disposed in the metallic cover. The insulation porcelain has a groove formed on an outer peripheral wall thereof to define a portion of a reference gas passage communicating between an air inlet formed in the metallic cover and the reference gas chamber.