Abstract: A decorative emblem with an enhanced depth of vision is provided. The decorative emblem comprises a decorative substrate, at least one layer of transparent plastic material formed on the top surface of the decorative substrate, and image or design printed on the substantially flat surface of the layer of plastic material, and a transparent plastic overlay flow coated over the image or design, the transparent plastic overlay has radiused edges to give an enhanced depth of vision to the decorative emblem by creating a lens effect and providing a floating appearance to the image or design.

Abstract: A pellicle for a photolithographic patterning process by means of a light having a wavelength of at most 200 nm, comprising a frame and a pellicle membrane bonded to the frame by means of an adhesive, wherein the pellicle membrane or the adhesive comprises the following fluorine-containing polymer (A): fluorine-containing polymer (A): a substantially linear fluorine-containing polymer having a chain of carbon atoms as the main chain, and containing as carbon atoms in its main chain, a carbon atom having one or two hydrogen atoms bonded thereto and a carbon atom having no hydrogen atom bonded thereto and having a fluorine atom or a fluorine-containing organic group bonded thereto.

Abstract: A composite plastic structure is described. The composite structure includes: (a) a shaped polycarbonate article having an edge region, the edge region having an adhesion-promoting geometric feature therein; (b) a coating applied to the surface of the shaped polycarbonate article; and (c) a polymer that is injection-molded or cast over the edge region of the shaped polycarbonate article. The polymer (c) envelopes the adhesion-promoting geometric feature of the shaped polycarbonate article (a). The envelopment of the adhesion-promoting geometric feature by the polymer (c) provides a structurally firm connection between the shaped polycarbonate article (a) and the polymer (c). Also described is a method of preparing the composite structure, and composite structures according to the present invention, such as picture frames, slide frames, windows having a seal or frame, and a glazing for a motor vehicle.

Abstract: Reticles and reticle blanks are disclosed, especially for charged-particle-beam microlithography, that include a peripheral frame and a support frame bonded to each other in a manner that substantially reduces distortion at the bonds as well as membrane distortion. The peripheral frame is bonded peripherally to the support frame in any of various manners including an anodic weld of glass and silicon (the glass containing mobile ions) and a eutectic metal silicon bond wherein the metal can be, e.g., gold, aluminum, germanium, or tin. The glass-silicon and eutectic bonds in which the metal is, e.g., gold, are also resistant to chlorine gas used for routine cleaning of the reticle. In the case of the eutectic metal bond, an intervening layer of chrome or nichrome can be applied between the metal layer and the bonding surface to enhance bonding.

Abstract: Device for the bordering of decorative material (1), in particular a carpet, a fabric or a sheet, a border (4) being capable of being formed in a die mold (2) for back-pressing and/or back-injection, at least parts of the edge (3) of this decorative material (1), characterized in that this border (4) comprises a rim (7) which extends essentially at right angles to the main direction of extent (8) and along the edge (3) of this decorative material (1) and which is essentially at right angles to the main direction of extent (8) of the decorative material (1) and comprises a multiplicity of fingers (9) engaging over and/or under the decorative material (1), this rim (7) and these fingers (9) being capable of being produced in one piece and of being connected to the decorative material (1) in the same operation.

Abstract: The present invention is an invention providing a photographic emulsion surface protective layer transfer sheet, characterized by having on one surface of a releasable support a photographic emulsion surface protective layer which is adhesive and in an uncured state, and characterized in that the photographic emulsion surface protective layer in an uncured state comprises an ionized radiation-curable resin composition containing a hydrophilic group-containing monofunctional (meth)acrylate and a polyfunctional (meth)acrylate. This transfer sheet can have an adhesive layer excellent in scratch resistance, close adhesion to an emulsion surface and solvent resistance. Therefore, when this transfer sheet is used particularly for forming a protective layer on the emulsion surface of a photomask, the photomask capable of long-term consistent use is obtained.

Abstract: A method and apparatus for maintaining a purged optical gap between a pellicle and a reticle in a photolithography system is described. A porous frame between a reticle and a pellicle maintains the purged optical gap. A porous frame includes a first and a second opposing surface. The first opposing surface defines a first opening, and is configured to mate with the pellicle. The second opposing surface defines a second opening, and is configured to mate with the reticle to enclose the optical gap between the pellicle and the reticle. A gas supply interface infuses a purge gas through the porous frame and into the gap.

Abstract: A removable pellicle for a lithographic mask that provides active and robust particle protection, and which utilizes a traditional pellicle and two deployments of thermophoretic protection to keep particles off the mask. The removable pellicle is removably attached via a retaining structure to the mask substrate by magnetic attraction with either contacting or non-contacting magnetic capture mechanisms. The pellicle retaining structural is composed of an anchor piece secured to the mask substrate and a frame member containing a pellicle. The anchor piece and the frame member are in removable contact or non-contact by the magnetic capture or latching mechanism. In one embodiment, the frame member is retained in a floating (non-contact) relation to the anchor piece by magnetic levitation. The frame member and the anchor piece are provided with thermophoretic fins which are interdigitated to prevent particles from reaching the patterned area of the mask.

Abstract: It is characterized by having a pellicle sheet made of a synthetic quartz glass having an OH group concentration of at most 100 ppm and containing substantially no oxygen deficient defect. It is particularly preferred that the OH group concentration is at most 10 ppm, and the internal transmittance is at least 80%/cm at a wavelength of 157 nm.

Abstract: An exchangeable decorative frame cover is provided for decoration. The exchangeable decorative frame cover includes a frame cover made of flexible material with a shape adaptable to a solid frame, and a means for securing the frame cover on to the solid frame, and releasing the frame cover from the solid frame. The exchangeable decorative frame cover can be made of fabric, leather, fur and plastics. Additionally, a kit is also provided, which contains a plurality of exchangeable decorative frame covers for providing a decorative picture frame an ability to be matched with eclectic decor. The kit can further include a picture frame together with a plurality of exchangeable decorative frame covers.

Abstract: Apparatus and methods to protect a photomask that is used for semiconductor photolithography at wavelengths either within or outside the visible spectrum include a pellicle that is removed during exposure. The pellicle sheet can be transparent or opaque. In one embodiment, a pellicle assembly comprises a base member aligned with a photomask, and an upper member in the form of a pellicle frame coupled to a pellicle sheet. The pellicle frame can be removed from the exposure path. When overlying the base member, the pellicle frame can be secured to it with a securing mechanism such as magnets, mating bevels, or mating male and female members. Detaching and handling elements, such as handles and/or recesses, can be provided to detach the pellicle frame from the base member and/or to move the pellicle assembly. Methods of using a pellicle assembly are also described.

Abstract: Apparatus and methods to protect a photomask that is used for semiconductor photolithography at wavelengths outside the visible spectrum include a hinged pellicle that is rotated away from the photomask during exposure. The pellicle can be transparent or opaque. In one embodiment, the photomask is supported by a photomask base, and the pellicle is hinged to one side of the photomask base. The pellicle can be moved away from the photomask by a robot arm. When covering the photomask base, the pellicle can be secured to it with a securing mechanism such as a vacuum arrangement. Methods of use are also described.

Abstract: A pellicle comprising a pellicle film, a pellicle frame supporting the pellicle film, and an adhesive resin layer provided on the surface of the pellicle frame on the side opposite to the surface supporting the pellicle film, wherein the adhesive resin layer is formed of a combination of a hard resin layer and a soft resin layer. The pellicle can be mounted on the mask and can be removed from the mask without giving damage to the mask, and does not spoil the flatness of the mask irrespective of when the mask surface is maintained in either the horizontal direction or the vertical direction.

Abstract: A pellicle utilizes a thin film attached to a substrate. The film is relatively transparent to radiation. The substrate is coupled to a periphery of the film and is exclusive of the center portion of the film. The pellicle can be manufactured by growing a relatively transparent film on a substrate and etching the substrate to expose a portion of the relatively transparent film.

Abstract: A pellicle includes a reticle, a pellicle frame, a pellicle film, and a capturing material. The pellicle frame has a reticle pattern surface formed with a reticle pattern. The pellicle frame has one end face bonded to the reticle pattern surface to surround the reticle pattern. The pellicle film is bonded to the other end face of the pellicle frame. The capturing material is formed on at least part of an inner surface of the pellicle frame to capture a deposition control material which is present in a gas in a space in the pellicle to control formation of a deposit on the reticle pattern surface. The space in the pellicle is defined by the reticle pattern surface, the pellicle frame, and the pellicle film. A pellicle case for accommodating the pellicle is also disclosed.

Abstract: A photomask structure with an anti-electrostatic-discharge (Anti-ESD) ability. The photomask structure comprises a photomask, a conductive dust pellicle, a conductive frame and a conductive film. The photomask possesses a first surface and a pattern is located on the first surface. The conductive dust pellicle is coupled with the photomask through the conductive frame and the pattern is enclosed by the conductive dust pellicle, the conductive frame and the photomask. The conductive film covers a surface of the photomask uncovered by the conductive dust pellicle and the conductive frame. The conductive dust pellicle, the conductive frame and the conductive film constitute a conductive structure enclosing the photomask.

Abstract: There is disclosed a pellicle having a pellicle frame with at least one vent for controlling atmospheric pressure and a filter attached so as to cover the vent, wherein it takes 5 minutes to 180 minutes, to restore a pellicle film swelled during a step of attaching the pellicle to the exposure original plate under atmospheric pressure of 760 mmHg followed by reducing atmospheric pressure to 500 mmHg and keeping the pressure, to the original state and a method for producing it, and a pellicle with a filter having a pellicle frame with at least one vent for controlling atmospheric pressure wherein all over the inner surface of the filter attached so as to cover said vent is impregnated with a resin, and 50% by volume or more of the filter is impregnated therewith.

Abstract: A fused silica pellicle for use on photomasks having increased durability and improved transmission uniformity and birefringence properties. The pellicle may be secured to the photomask using an adhesive or a slide rail system, or may be held in place using a static charge.

Abstract: A bulletin board includes a generally planar polyfoam layer having a front surface and a back surface, wherein the back surface includes a recessed surface portion formed therein having an integrally disposed generally planar stiffening member held in place by the polyfoam. The planar stiffening member is preferably a cardboard piece and the polyfoam penetrates a portion of the corrugation from peripheral edges thereof inward. A method of forming the bulletin board is provided.

Abstract: A pellicle for protecting a reticle, on which a circuit pattern is formed for manufacturing a semiconductor device, from an attachment of a foreign matter, comprising: a pellicle film having a predetermined thickness, through which a light transmits to the reticle; and a pellicle frame, on which a periphery of the pellicle film contacts, including: a body part having a frame shape, the height of which is substantially constant all over the body part; and an upper protruding part formed on an upper end of the body part that protrudes upward from the upper end of the body part for directly contacting with a surface of the pellicle film, the height of the upper protruding part being constant all over the upper protruding part.

Abstract: A fabric having plant material adhered between layers of silk or hand-made paper. The silk or paper layers are translucent to allow the fabric to have the appearance of plant material. The fabric is manufactured by soaking dry plant material in water, pressing and drying the plant material to flatten it, adhering bottom and top layers of silk or paper to the plant material, and applying a stiffening agent to the fabric. Articles of various shapes may be formed by shaping the fabric into a predetermined shape prior to the step of applying the stiffening material.

Abstract: A combination including a container having a back plate and a transparent receptacle secured to the back plate, and one or more liquid dissolvable capsules containing compressed, resiliently expandable toy figurines confined in a chamber between the receptacle and the back plate is disclosed. One or more openings are formed in the back plate which communicate with the chamber between the receptacle and back plate so that warm water can flow into the chamber to dissolve the capsules to release the toy figurines upon immersion of the container in a warm liquid such as a child's bath water, the container thus preventing young children from handling the capsules directly.

Abstract: A decorative molding/casing for use in decorating a room or furniture as disclosed. The decorative molding/casing in general has a routed or lazered front surface establishing a front face section. The rear surface of the molding/casing is preferably milled to create a longitudinal groove which establishes a first interior surface and a pair of symmetric support sections. Any desired artistic design cutouts may then be routed or lazered through the front face section and through the first interior surface into the longitudinal groove. A filler material is then colored or selected. The filler material may then be positioned within the longitudinal groove between the pair of symmetric support sections. The colored surface of the filler material may then be positioned proximate to the first interior surface where the filler material may be secured to the first interior surface by any preferred means as desired by an individual.

Abstract: A method and apparatus for temporarily attaching a pellicle membrane and frame to a photomask substrate until the assembly passes inspection, and then permanently bonding the frame to the substrate. In the preferred embodiment, a vacuum channel is provided in the pellicle frame to permit a vacuum to be drawn between the frame and the substrate. In alternate embodiments, a static adhesion is obtained between the flat surfaces of the pellicle frame and the substrate, and this static adhesion is improved by wiping a solvent on the bottom surface of the pellicle frame.

Abstract: An ornament having a printed insert bearing a personalized message or picture that is suspended within a transparent bulb. The printed insert is produced by printing the personalized message or picture onto transparency paper using a computer and color printer, and cutting the transparency paper to form a disk-shaped insert that is sized to fit within the transparent bulb. The printed insert is then curled and inserted through the opening of the transparent bulb, and is then suspended within the transparent bulb from a cap using a hitch pin (fastener).

Abstract: A mouse pad with improved self-cleaning and traction features. The mouse pad is a planar structure with a parallel top control layer and a bottom anti-skid coating. Formed on the top layer is a top control layer with a plurality of alternating, equal height, prismatic and pyramidal shapes, which provide improved cleaning and traction properties. Small troughs are formed between the adjacent shapes, which collect fine dirt and dust particles that are swept from the surface of the mouse ball during use. In one embodiment, the top control surface is made of flexible material that allows the prismatic and pyramidal shapes to bend slightly when the ball of a mechanical mouse rolls over the top surface. This bending action provides improved self-cleaning and traction features. In another embodiment, the top layer is made of transparent material. An ink layer may be applied to the bottom surface of the top layer.

Abstract: A framing device, used for displaying items such as photographs, certificates and the like, includes a translucent sheet-like material having an outward side and an inward side, both having a common continuous edge. An adhesive is applied along the inward side adjacent to the continuous edge in such a manner that a portion of such edge remains adhesive-free. A sheet of backing material has a first side and a second side and the first side of such foam is positionally secured by the adhesive and with respect to the translucent material. And a release liner is attached to the second side of the backing material. The adhesive-free portion of the edge and the sheet of backing material define a slot permitting insertion and removal of an item to be displayed.

Abstract: There is disclosed a pellicle for photolithography comprising at least a pellicle membrane adhered to a pellicle frame, wherein the pellicle membrane exhibits light transmission of 50% or more when it is irradiated by an excimer laser having a wavelength of 160 nm or less. The present invention provides a pellicle for photolithography comprising a pellicle membrane of high light transmission and excellent durability even after long term irradiation with a vacuum ultraviolet light of a short wavelength.

Abstract: To improve a device for protecting electronic circuits from unauthorized access so that it can be produced inexpensively, can be handled and guarantees increased security, the invention proposes a device for protecting electronic circuits from unauthorized access with at least one hood-type cover element, which is arranged on a circuit plate covering it at least in some areas and has tracks that can be connected to a detection circuit to detect mechanical damage, wherein the cover element is made of a material that is very hard and at the same time very brittle.

Abstract: The invention relates to a mechanically assembled picture comprising at least one image element comprising an image on a thin polymer sheet, a brace, and a transparent polymer sheet overlaying said image and brace, wherein said transparent sheet mechanically holds said image to said brace.

Abstract: There is disclosed a jig for producing a pellicle comprising a support frame having an opening, and an adhesive layer provided at periphery of the opening, wherein the adhesive layer is composed of a polymer material having a glass transition temperature within a range of 0° C. to 300° C. The jig of the present invention can be repeatedly used without reforming the adhesive layer after use.

Abstract: A floor mat for protecting a floor surface beneath a baby's highchair, or other area prone to spillage, is substantially composed of a flexible, water impervious body of a sufficient overall thickness to be rollable for washing and storage. The floor mat can be comprised of a laminate of top and bottom transparent plastic layers with a central paper layer. The paper layer can carry a graphic decoration on one or both sides. The floor mat can alternately be composed of a single sheet having graphic decorations applied directly to one or both surfaces of the sheet.

Abstract: A recyclable mask which includes: a substrate which is optically transparent; a thin film having non-transparent-layer patterns on the substrate; a pair of mask frames placed on each marginal portion of upper and lower surface of the thin film; at least one mask frame holder fixing the mask frames and the thin film as a single body; a pellicle frame which is attached to a portion of top and bottom surfaces of each mask frame; and a pellicle attached to top and bottom surfaces of each pellicle frame and thus covering a center part of the thin film.

Abstract: An enhanced structure of an animated ornament composed of a globular shell, a hollow ball, a piece of non-magnetic, high-density material (such as copper, tin, plastic etc.), an inner magnet and an outer magnet. The hollow ball, having decorative figures, is smaller than the globular shell and is included in the globular shell. The space in between the globular shell and the hollow ball is filled up with liquid so that the hollow ball floats in the liquid and, when being shaken, turns around in all directions. Inside the lower part of the hollow ball attached a piece of non-magnetic, high-density material, such as plastic, copper and tin, and an inner magnet is fixed on the top of the non-magnetic material.

Abstract: A mask structure to be used for X-ray exposure or the like in manufacturing semiconductor devices prevents contaminants from adhering and accumulating on the surface of a mask, thereby extending the life of the mask. In this mask structure, titanium oxide films are formed on front and back pellicles that protect a mask, composed of a support film and an X-ray absorber, from dust or the like. Titanium oxide decomposes contaminants by functioning as a photocatalyst, and prevents the adhesion and accumulation of contaminants by an antistatic function based on photoconductivity. When a titanium oxide film is formed on the surface of the mask itself, it is preferable that the film be formed outside the exposure area or the like.

Abstract: A tile with a transparent glass body having a smooth front face and a three-dimensional design impressed on the rear face that is viewed through the front face. The impressed design is further defined by a layer of decorative glass materials fused to the impressed design as well as some or all of the rear face. An overlay of glass material is fused to and follows the topography of, the decorative glass materials layer and/or the rear face of the glass tile body, sandwiching the decorative glass materials layer between the glass tile body and the glass material overlay. Once fused; the glass material overlay, the decorative glass materials layer and the glass tile body meld to become one homogenous glass layer, the tile, that cannot delaminate. The overlay is an interface glass matrix that provides a point of attachment that can support the glass tile module of this invention when the glass tile is attached to a surface to be covered.

Abstract: According to the present invention, a method of manufacturing a pellicle and a jig for manufacturing a pellicle are provided.

Abstract: An object containing pressed flowers sealed therein which is composed of a base layer, an intermediate layer of molten resin in which is sealed a pressed flower, and a surface layer of transparent film, with these three layers integrally laminated on top of the other, characterized in that the intermediate layer is formed by pressing with heating under reduced pressure from a meltable porous plastic film such that the molten plastic adheres closely to the pressed flower to seal it and also fixes the pressed flower to both the base layer and the surface layer of transparent film. It retains the natural color of the pressed flower for a long period of time without deterioration by air and moisture.

Abstract: A window device for use in a motor vehicle, comprises a resin window panel having at least one pair of rib members protrudingly formed on the inner surface thereof, said pair of rib members being facing each other and each having an outwardly facing tip portion; and a reinforcing member having at least one engaging hole corresponding to the at least one pair of rib members. By inserting and fixing the tip portions of the at least one pair of rib members in the at least one engaging hole of the reinforcing member, the resin window panel and the reinforcing member may be combined together so as to form the window device for use in an automobile.

Abstract: Methods and apparatus which enable the lateral displacement of windows and window elements in reaction to overpressure forces resulting from an explosion are disclosed. According to the present invention, these forces are released to the edges of the displaced window and window elements, and the window itself remains intact or does not release life-threatening or injurious projectiles. One embodiment of the invention (10) comprises a window frame (12) which holds a pane of glass or synthetic material such as acrylic or polycarbonate (14), the frame (12) being coupled to a window receiving pan or receptor (16) by a plurality of retainers (18). The overpressure from an explosive blast causes the frame (12) to be displaced primarily laterally from the receiving pan (16) thereby releasing the blast overpressure (20) to the edges of the displaced frame (12) and reducing the risk of release of shrapnel from said sheet of generally light transmissive material (14).

Abstract: A mask structure to be used for X-ray exposure or the like in manufacturing semiconductor devices prevents contaminants from adhering and accumulating on the surface of a mask, thereby extending the life of the mask. In this mask structure, titanium oxide films are formed on front and back pellicles that protect a mask, composed of a support film and an X-ray absorber, from dust or the like. Titanium oxide decomposes contaminants by functioning as a photocatalyst, and prevents the adhesion and accumulation of contaminants by an antistatic function based on photoconductivity. When a titanium oxide film is formed on the surface of the mask itself, it is preferable that the film be formed outside the exposure area or the like.

Abstract: A combination instrument (1) has a front frame (2) having a cover (7) which has a plurality of recesses (4, 5) for indicating instruments or other displays. The cover (7) is covered with a decorative element which is formed as a molding (3) and around which a section (8), which is designed as an undercut, of the front frame (2) grips. To this end, the front frame (2) is produced in an injection molding process, the molding (3) being placed into the injection mold. The connection of the molding (3) to the front frame (2) can take place such that it is invisible to someone looking at it, thereby enabling an attractive, visual appearance and simultaneously reliable way of fixing it to be achieved.

Abstract: A photomask (1) comprises a transmissive base plate (2), a first side of which is provided with a layer of a metallic mask material (4). In this layer, a mask pattern (6) is formed which is enclosed in an outer region (5) of mask material. The photomask is encapsulated in a protection layer (9) of transmissive and conductive material, which, on the first side of the base plate, is formed at such a distance from said first side that said protection layer remains free of the mask pattern. The photomask is thus protected against electrostatic discharges which could damage the mask pattern, and the projection of the mask pattern is not adversely affected.

Abstract: Activity or craft apparatus and method for simply, quickly and inexpensively creating a thin lithophane-like pictorial work that provides a picture or image when light passes through the work from the rear. The work is formed from a formable translucent material. One form of illustrated apparatus comprises a generally closed container having a transparent see-through front wall. On the rearwardly inwardly facing side of the wall it has a contoured forming surface that is the reverse image of a desired contoured recessed picture-providing surface of a desired lithophane-type work. The illustrated container also has a second or rear wall that is generally parallel to and closely spaced from the front wall. The rear wall is translucent or transparent so that the light can pass through it from the rear.

Abstract: A pellicle that prevents adhesion of an adhesive pushed out from a pellicle frame to an original circuit pattern of a mask when mounting the pellicle to the mask. An end surface of the pellicle frame to be fixed to the mask has a taper-shaped notch formed by notching a rim along the entire peripheral surface of the pellicle frame in the peripheral direction. The adhesive is applied to the notch.

Abstract: A pellicle for a photolithographic patterning process by means of a light having a wavelength of at most 200 nm, comprising a frame and a pellicle membrane bonded to the frame by means of an adhesive, wherein the pellicle membrane or the adhesive comprises the following fluorine-containing polymer (A):

Abstract: Transparent edge sealed window films substantially minimize (if not eliminate entirely) degradative effects on the window film, particularly solar-reflecting metals and/or oxides associated with multilayer window films, caused by ambient conditions (e.g., commercial window cleaners, salt and the like). The edges of window films are preferably sealed by a liquid solvated polymeric material which, upon curing, provides a solid transparent seal which significantly minimizes the degradative effects of the ambient environment. Most preferably, the window film whose edges are sealed will include a transparent thermoplastic (e.g., a polyester) film layer and a solar-reflecting metal and/or oxide applied onto a surface of the film layer. The sealant for such a preferred window film will be a polyester-type sealant which has silane end-group functionality and substantially no free isocyanate groups.

Abstract: Optical diffusing structures can be fabricated from photopolymerizable material by directing light through a transparent or translucent substrate and then through the photopolymerizable material for a period of time sufficient to photopolymerize only a portion of the material. The resultant structure can be utilized as a diffuser, a viewing screen, and in other applications, and can be combined with other light-directing structures such as arrays of tapered optical waveguides.

Abstract: A glass panel having a simulated metal strip applied thereto in a decorative pattern, and a method for making a glass panel having a simulated metal strip applied thereto in a decorative pattern, including a flat panel of glass, a raised bead of air-curable acrylic resin applied in a prescribed pattern to at least one surface of the flat panel of glass, and a metal film overlying the bead of acrylic resin.

Abstract: The present invention relates to a bulletproof glass window, in particular for use as a lowerable side window of a motor vehicle, with plural glass panes (1, 3, 5) arranged in layers and laminates (2, 4), with at least one laminate being positioned between two adjoining glass panes in each case, in order to join the two glass panes, with a grading or stepped portion that is formed at the edge of the bulletproof glass window and with a projection (8) for lodging the bulletproof glass window in a chassis (14) or door frame, and with a metal armoring which, in the area of the projection (8), at least covers the inner surface of the projection, in the area of the grading or stepped portion a recess (12) being formed on the face, and the metal armoring (6) extending into the recess (12).