Abstract: A die assembly (10) for controlling extrudate profile dimension. The die assembly includes a die block (12) having a feed passage (16) for movably supporting a diverter member (13) within the die block, and first and second die block passages (18, 20). The diverter member (13) includes a diverter passage (32) and first and second feed openings (34, 36) interconnected by the diverter passage. One of the first or second feed openings (34, 36) has a larger diameter than the other of the first or second feed openings. The diverter member (13) is movable with respect to the die block (12) for directing extrudate flow via the diverter passage (32) through the second die block passage (20), to thereby vary the profile dimension of the extrudate exiting the die block. The die block (12) additionally includes a disposal passage (22).

Abstract: A method for forming cable which is insulated with a rigid insulating layer into a desired shape, comprising the steps of wrapping the a portion of the cable with a heater tape that houses heater elements, causing the elements to become hot and heat the cable portion so that its insulating layer is heated and loses its molecular memory of its prior configuration, and reconfiguring the cable portion into the desired shape.

Abstract: In a first forming stage, the bottom portion of a mono-molded plastic syringe (a type wherein the whole portion, i.e., a main syringe body and a needle portion, is molded unitedly in a cast) is heated and then stretched to a certain length, forming the edge portion like a needle, while the syringe is intermittently moved. Then the sryinge is carried to a second forming stage, where the syringe is moved intermittently and the needle portion is heated, then it is bent at a certain angle and is cut in a certain length, forming a completed syringe.

Abstract: Apparatus and method for removing particulate impurities from liquids wherein the liquid flows upward through a bundle of tubes having a helical shape to present an inclined path where settling of particulates back down the tube occurs. The bundle is preferably formed around a central standpipe. This modular helical tube bundle arrangement provides a compact and inexpensive structure and great convenience for maintenance. The preferred cross sectional shape of each tube is oval to increase settling rate. In order to form the tubes from rigid tubing, a concrete form is made in accordance with a procedure which includes forming a "tent" of strings, sculpting a plasticene negative form using the tent of strings as a guide, casting concrete against the form to produce a mold that resembles a sliding board with an outside drooping edge.

Abstract: A method of and apparatus for shaping thermoplastic tube by external formers using pulsed emission of short wave infra-red radiation to soften the thermoplastic material with the tube held in the required configuration on the formers followed by air cooling to harden the thermoplastic material and retain the required configuration.

Abstract: For the corrugated deformation of a flat sheet of material, an upper row (2) of shaping tools (4) is pressed against a lower row (3) of shaping tools (5). The shaping tools of both the rows are, with that, also simultaneously pushed together so that they trace the shortening of the sheet of material during the deformation. Thus, the situation is achieved where no relative displacement between the sheet of material and the facing sides (6, 6') of the shaping tools (4 and 5) takes place, also in the case of numerous corrugations of relatively great height. The lower row of shaping tools is arranged on a rotor, whilst the upper row is fixed at a working station within the area of rotation of the rotor.

Abstract: An electrostatic air cleaner collector and/or ionizer section has their oppositely charged elements being formed of single, continuous, electrically conductive elements, spirally wound around insulator rods to jointly define a spiral passage through which air is caused to flow. The collector and ionizer may be assembled separately by such a winding process, or they may contain common insulator rods around which the conductive element of both sections may be simultaneously wound. A conductive rod may be inserted to electrically interconnect the high voltage elements of the respective ionizer and collector sections.

Abstract: In the method an apparatus engages pre-cut lengths of heated thermoplastic pipe against a pair of eccentric wiper arms bending the pipes into elbows. The eccentric wiper arms have an eccentric portion and a constant radius portion. A bending form has an arcuate die adapted to hold a pre-cut length of pipe. Four such bending forms are radially connected to a rotation shaft which is journalled at each end to a support frame. A continuous supply of pre-cut lengths of pipe are transported through a heating chamber by a set of endless chains. Each pipe is then transferred to a bending form which is rotated by the shaft so that the cold end portions of each pipe engages the spaced apart and substantially parallel eccentric wiper arms. The wiper arms urge the end portions of each pipe length slightly beyond the outer edges of each arcuate die to compensate for the effect cooling has on each pipe length. Once the pipe is bent, the rotation of the bending form causes the pipe to drop into a tank of water.

Abstract: An apparatus for bending a laminated thermoplastic sheet without displacing the lamina relative to one another includes a clamp which functions to hold the sheet during the bending procedure. A support is disposed adjacent the clamp and has a curved surface for forming a bend in the sheet and a flat surface which constitutes an abutment for the part of the sheet being bent. The support is adjustable to vary the angle of bending. A bending device for the sheet comprises a carriage having a bending roller, and a ram whose size approximates that of the flat abutment surface. The sheet is clamped with a portion thereof projecting freely above the flat abutment surface and heated. The bending roller thereupon forces the sheet against the curved surface to bend the sheet and then moves across the projecting portion of the sheet to urge such portion into engagement with the flat abutment surface.

Abstract: High aspect ratio boxes and sleeves are molded inside out by molding the outer surfaces of box covers and bottoms and sleeve sides in closely spaced parallel relationship, with side walls extending outward. Backs are joined to the covers and the bottoms by living hinges. The inside out molding process and apparatus reduce effective mold areas and mold forces, providing capacities to mold more boxes at a time in existing press facilities.

Abstract: A hydraulic or pneumatically actuated muscle has an elongated elastomeric tubular bladder covered by a tubular braid. The bladder has a fold or invagination along its length. The process for forming this bladder can employ a fixture in the form of a threaded rod. A tubular elastomer is wrapped into the v-shaped thread on the rod. Then the wrapped rod is subjected to heat to set a fold into the tubing. The invaginate bladder can be subjected to a second, mild heat treatment to reduce curling.

Abstract: A bending machine for thermoplastic workpieces includes a first clamp assembly having first and second clamping jaws. A second clamp assembly is disposed along a first side of the first clamp assembly and includes third and fourth clamping jaws. The second clamp assembly is displaceable relative to the first clamp assembly, and the fourth clamping jaw is in planar alignment with the second clamping jaw. A heater assembly includes at least a first heating knife disposed along the first side of the first clamp assembly, and is displaceable relative to the first clamp assembly. A bending jaw is disposed along an opposite second side of the first clamp assembly and is pivotal between a first position in planar alignment with the second and fourth clamping jaws and a second position angularly disposed relative thereto.

Abstract: An improved method for manufacturing a laminate wherein the edges of a deformable surface layer, such as cloth or carpet, are folded under and releasably secured to the undersurface of the deformable surface layer. The deformable surface layer is then placed into a mold unit and the securement between the folded edge and the undersurface of the deformable surface layer is released either prior to or during the injection of a plastic material for forming a plastic support layer. The method produces a laminate including a deformable surface layer having edges which are folded under and totally bonded to the plastic support layer. The bonded edges improve the securement between the deformable surface layer and the plastic support layer and give the laminate a "finished" appearance without tacks or staples.

Abstract: A method of making a prevulcanized tread particularly useful for the recapping of tires having, in stress-free condition, a constant curvature in its longitudinal direction whose radius corresponds substantially to that of the tires to be recapped, the sole of the tread being concave, is characterized by the fact that the tread has two ends in its longitudinal direction. The method includes feeding continuously a strip of raw rubber to an inner mold moving about an axis in a curved path, closing an outer mold for the tread pattern with the inner mold so that the closed molds form a continuous molding space within which the tread is completely molded and vulcanized as the closed molds move together about an axis of rotation, and opening the moving molds to discharge continuously in the longitudinal direction the prevulcanized tread of constant curvature.

Abstract: A process for continuously and progressively forming components from fiber-containing composite material workpieces having a deformable matrix introduces transverse bends into a workpiece that moves through the apparatus in a longitudinal or travel direction. Transverse bending of the composite material is accomplished in a kinematically admissible manner to avoid misalignment or failure of the composite material. A net bending deformation is introduced at a free transverse edge as the composite workpiece moves in a longitudinal direction, by pairs of compound roller elements between which the workpiece passes as it moves through the apparatus. The net deformation introduced at the free transverse edge is moved and distributed through the composite material workpiece during successive passes through the forming machinery, to form the final shaped component.

Abstract: A method for forming a return flange on the belt trim portion of a vehicle door panel which includes the steps of locating the door panel on a holding fixture to place the belt trim portion for sequential clamping, backing, spot heating and folding to form the return flange thereon; apparatus for practicing the method which includes a door fixture means with movable backing member to back a belt trim portion when the panel is clamped in place; and a heater mechanism and a flange former mechanism on the machine are sequentially advanced with respect to the clamped door panel to soften a thermoformable segment of the panel which is folded about the back-up plate.

Abstract: A method is shown for forming a flange on an end of a plastic pipe liner of the type used to line a tubular member. A reinforced disc having a rigid portion and an elastomeric portion is placed about the liner exterior and moved into position flush with the flanged end of the tubular member. A retaining ring is placed about the reinforced disc and the disc and liner exposed end are heated to render the materials malleable. A forming unit is then used to apply force to the liner to flow the liner into a reformed shape having a greater external diameter than the remainder of the liner. The forming operation also bonds the reinforced disc to the reformed liner end to further resist any tendency of the liner end to be retracted into the interior of the tubular member.

Abstract: A twisted FRP structure having sufficient strength and flexibility is produced by providing a rod member disposed centrally and twist a plurality of side strands twisted around the rod member in the same direction at a predetermined pitch. At least the side strand includes a composite strand having an FRP element from by impregnating fibers with an uncured thermosetting resin and a thermoplastic coating on such FRP element, the thermosetting resin being cured after the side strands are twisted around the rod member. The twisting pitch is not less than 25 times the outside diameter of the FRP element in the side strand.

Abstract: A system for forming an I-section workpiece includes a transporter having a pair of mandrels onto which two unformed charges are placed. The transporter carries the mandrels to a forming station which includes a pair of forming enclosures which contain heating elements and compliant material therein. By insertion of the mandrels into the compliant material, the charges are caused to bend around the mandrels thereby generating a pair of formed elements having channel shaped cross-sections. The elements are then carried by the transporter to a cure station where they are joined together by heated mandrels so that a one piece I-section workpiece is formed.

Abstract: A method of constructing a cambered, pre-cast concrete panel and joist assembly comprising creating a mold on a backer surface, positioning reinforcing members, joist attachment plates and weld plates within the mold, pouring wet concrete into the mold, embedding anchor members in the concrete, letting the concrete harden, raising the ends of the concrete panel, attaching cambered joists to the panel and installing said assembly in a construction site. Both the concrete panel and the joists of the concrete panel and joist assembly are cambered. The joists are constructed with or without a top chord.

Abstract: A method for forming a mask to be placed over at least a portion of an individual's face wherein a plurality of overlapping folds are formed in the sheet of material while the sheet of material is formed into the mask shape, the overlapping fold cooperating to maintain the sheet of material in the formed, predetermined mask shape.

Abstract: A method is described for bending an extrudate exiting an opening in an die assembly without substantially changing the cross sectional shape of the extrudate. The method includes the step of channeling the flow of extrudate from an extruder through a flow channel and the opening in the die. The opening in the die is rotated with respect to the feed opening to vary the length of the flow channel and pathways along which extrudate flows thereby variably directing flow of the extrudate as the extrudate exits the opening in the die.

Abstract: A die assembly for configuring extrudate flow is provided. The die assembly includes a die head having a feed member passage, first and second die head passages, and first and second die surfaces respectively associated with the first and second die head passages. The die head passages are located intermediate the corresponding die surfaces and the feed member passage. A feed member is supported in the feed member passage of the die head and has a feed passage and a feed opening for supplying extrudate to the die head. The feed member is supported for relative movement within the die head whereby the feed opening may be moved to communicate with either the first die head passage or the second die head passage. The central axis feed of the feed opening is moveable with respect to the central axis of the first or second die head passage to correspondingly configure extrudate exiting the respective die head passage when the feed opening is in communication with this die head passage.

Abstract: An apparatus engages pre-cut lengths of heated thermoplastic pipe against a pair of eccentric wiper arms bending the pipes into elbows. The eccentric wiper arms have an eccentric portion and a constant radius portion. A bending form has an arcuate die adapted to hold a pre-cut length of pipe. Four such bending forms are radially connected to a rotation shaft which is journalled at each end to a support frame. A continuous supply of pre-cut lengths of pipe are transported through a heating chamber by a set of endless chains. Each pipe is then transferred to a bending form which is rotated by the shaft so that the cold end portions of each pipe engages the spaced apart and substantially parallel eccentric wiper arms. The wiper arms urge the end portion of each pipe length slightly beyond the outer edges of each arcuate die to compensate for the effect cooling has on each pipe length. Once the pipe is bent, the rotation of the bending form causes the pipe to drop into a tank of water.

Abstract: An apparatus for forming a return flange on the belt trim portion of a vehicle door panel includes a door panel support with a movable backing member to back a belt trim portion when the panel is clamped in place. The apparatus further includes a heater mechanism and a flange former mechanism on the machine which are sequentially advanced with respect to the clamped door panel to soften a thermoformable segment of the panel which is folded about the back-up plate.

Abstract: A laminate bending device includes a pair of parallel shafts extending outwardly through transverse slots in a front wall of a housing. A pair of clamping jaws on the shafts each include an elongated slot for the insertion of a narrow strip of a laminate material of the type sold under the trademark FORMICA. Each of the shafts are mounted within the housing for linear and rotary movement. A spring biases each of the clamping jaws toward a stop on the front wall of the housing. In use, a strip of laminate material is inserted into the slots of the clamping jaws, the spacing of which has been previously adjusted to determine the bending radius. A heating element is then activated to heat the strip and allow the spring biased force on the clamping jaws to bend the strip to the desired radius. A cooling mechanism is activated upon completion of the bending to cool the strip and set the deformed shape.

Abstract: A method of making an elongated structural element of fiber reinforced plastic material with a solid walled casing. A hollow tubular casing is generally simultaneously filled with elongated strands of continuous fibrous reinforcement and plastic material and solidified. The casing is part of the final product. An internal casing may also be used where the fiber reinforced plastic is between the internal and external casings. The elongated structural element may be initially shaped prior to solidification or after reheating reshaped into another shape such as a helical coil or spring.

Abstract: A method of forming a circular opening in a layered sheet material to be subsequently bent which causes the layers to shift relative to one another in a direction normal to the bend including the steps of piercing the layers material with an oblong opening the spaced apart circular end configurations, then bending the layered material so that the opposite end portions in different layers are moved toward one another sufficiently so that a final circular opening is formed.

Abstract: In a method for the production of cylindrically symmetric bodies with given radial gradient of the material properties, for example of the refractive index, at least two rod-shaped molded bodies consisting of materials with different properties are joined in parallel and, following lowering of the viscosity of both materials, the bodies are twisted many times in a spiral around a longitudinal axis, such that a desired radial gradient of the material properties arises, where metallic, semiconducting, or insulating materials may be used, and the viscosity is varied through changing the temperature or adding or removing a solvent.

Abstract: The invention relates to a method for forming twin-wall polycarbonate sheets into desired arcuate forms to be used, for example, as awnings. The method is distinguished from known forming techniques which are generally not effective in forming the polycarbonate sheets hereinafter described.The method generally includes preheating a portion of the polycarbonate sheet within a heating chamber, engaging the sheet with the mould which is pivotally mounted to the frame of an apparatus within the heating chamber, frictionally restraining the movement of the sheet with respect to the frame at a position spaced from the mould, and outside the heating chamber, and pivoting the mould so as to form the sheet.The present invention generally overcomes the difficulties in forming twin-walled polycarbonate sheets thereby allowing this material to be used in place of other conventional awning materials such as fibreglass and corrugated iron.

Abstract: A method of manufacturing a decorative object made of colorless transparent or colored semi-transparent synthetic resin is provided wherein a film, on which letters, patterns or the like are displayed, is bonded to a notch-cut back side of the object. The steps of the method include setting the film onto a notch-cut and engraved surface of a die half, closing the die half with another die half, and injecting the transparent or semi-transparent synthetic resin into the closed die halves to mold the decorative object and to closely bond the film to the notch-cut surface of the decorative object thus molded.

Abstract: A compact wire straightener module having a plurality of curved tubes for simultaneously straightening a large number of wires. Each tube bends its wire in a first plane and then bends the wire in a second plane perpendicular to the first plane. The wires are not pulled through the wire straightener module; but rather, after one end the wires has been secured, the wire straightener module moves in a horizontal direction along the wires to perform the straightening operation. This movement of the wire straightener module allows for use in a compact automatic cable assembly by eliminating the need for a separate mechanism to pull the wires through the wire straightener module. Further, each tube is a continuous assembly so that threading wire through the module is simple and fast.

Abstract: A magnetic disk recording/reproducing head device includes a slider member, a magnetic circuit, and a seal member. The slider member is made of a magnetic material and has a sliding surface opposing a recording/reproducing disk, both end portions in a direction parallel to the sliding surface. The slider member has a groove portion which is formed in one of the end portions to be parallel to the sliding surface. The magnetic circuit has a core member made of a magnetic material and fixed to the other of the end portions of the sliding member, a predetermined magnetic gap which is formed between the core member and the slider member, and has a coil which is wound around the core member. The seal member made of a material having an adhesive property upon melting and a shrinking property upon stiffening and sealed in the groove portion of the slider member so as to form an inwardly recessed tapered portion on part of the sliding surface corresponding to the groove portion.

Abstract: Thin-walled catheters are provided which have an elongated fuseless polymeric tube that is made from a single tube of extruded polymer. The elongated fuseless polymeric tube includes a body portion that had been subjected to a high temperature zone in order to solid state polymerize and enhance the mechanical stability, burst strength and kink resistance of the body portion. Also included is a tip portion of the elongated fuseless polymeric tube which was subjected to a low temperature zone to retain the initial properties of extruded polymer.

Abstract: An apparatus for continuously and progressively forming components from fiber-containing composite material workpieces having a deformable matrix introduces transverse bends into a workpiece that moves through the apparatus in a longitudinal or travel direction. Transverse bending of the composite material is accomplished in a kinematically admissible manner to avoid misalignment or failure of the composite material. A net bending deformation is introduced at a free transverse edge as the composite workpiece moves in a longitudinal direction, by pairs of compound roller elements between which the workpiece passes as it moves through the apparatus. the net deformation introduced at the free transverse edge is moved and distributed through the composite material workpiece during successive passes through the forming machinery, to form the final shaped component.

Abstract: A method of shaping elongated composite structures of a resin matrix reinforced with randomly broken fibers oriented in transverse and non-transverse directions with respect to the longitudinal axis of the structure is implemented by a computer aided apparatus for forming the structure. The apparatus is provided with a heated fixed forming tool, a means for stretching the structure from each end and means associated with the forming tool for separately holding each formed component length of the structure in place against the forming tool. The formed structure is characterized by the particular orientation of the fibers in the transverse and non-transverse direction after the structure is formed.

Abstract: A reverse osmosis water purification module has an enclosed cylindrical housing in which at least twelve purification elements are mounted in a uniform, spaced parallel fashion. Each element consists of a long flat member having a thermoplastic sheet backing formed into a slightly curved cross section and having a semi-permeable membrane disposed thereon. The backing has three-dimensional porosity for purified water such that water passing through the membrane portion of the element travels along the backing member to an end. The ends of the module are mounted in a collection manifold which is sealed off from the remainder of the housing interior. A method of manufacturing the elements continuously is also provided wherein a continuous length of flexible backing material is fed sequentially through a heater, a forming die to impart a curved cross-section to the backing material, an extruder wherein membrane forming fluid is extruded around the periphery of the backing, a chill bath and a heating bath.

Abstract: Applicator syringe for a dental compound, with a syringe body (1) tapering into a thin discharge tube (3) and with a piston (5) displaceable in it, the applicator syringe being intended for once-only use. To avoid the need for special actuating tools, but make easy use possible, the effective cross-sectional surface is very small, in particular with a ratio of the useful stroke to the diameter of the syringe piston of at least approximately 10. So that the syringe can nevertheless be filled easily, the diameter of the cylindrical space in the rear portion of the latter is larger than the piston diameter. The syringe body (1) is first produced in a straight form and only thereafter is the discharge tube (3) bent.

Abstract: A cleated dust control mat having a rubber or rubber-like backing in which the longitudinal edges of the rubber-like backing projecting outward from the pile surface thereon is smooth and thicker than the body of the rubber or rubber-like backing material. The thicker edges are produced by using a perforated silicone pad which is narrower than the desired width and has beveled edges thereon to provide a curved transition therein between the body and the longitudinal edges of the backing material.

Abstract: A method and apparatus for buckling contact lenses includes mounting a lens blank to be buckled on the contoured surface of a lens mounting tool so that the lens adopts a datum position, bringing a protruding element or elements into contact with the lens, such that the lens' contact point is coincident with the datum level, setting an indicator gauge to a setting to indicate the position of the contact point, moving the element or elements away from touch contact with the lens, setting a new elevation of the mounting tool by displacing the mounting tool over a distance commensurate with the predetermined degree of buckling of the lens required, and bringing the protruding element or elements into descending engagement with a portion of the lens, thereby buckling the lens to the shape of the contoured surface of the lens mount until the protruding elements have been displaced, the predetermined distance relative to the datum.

Abstract: A flat stock strip of thermoplastic material is passed through a heating station in contact with the edges of longitudinally oriented heated knife blades to heat soften the stock strip along narrow longitudinal lines to define localized fold lines for the stock strip. The strip is fed sequentially through a prebending device and a chilled forming die to set the reformed strip at the fold lines. Preferably the knife blades and any strip contact surfaces of the prebending device and the chilled forming die are PTFE covered to eliminate scratching of the thermoplastic stock strip material during heating, reforming and cooling.

Abstract: The specification describes and claims a method of making therapeutic rings from a curable silicone rubber based composition. The rings are capable of controlled release of the therapeutic agent in the human or animal body. The method includes the steps of:(i) extruding a first composition comprising a therapeutic agent and a first elastomer-forming silicone composition to provide a core;(ii) extruding a second composition comprising a second elastomer-forming silicone composition to provide a sheath enclosing the core;(iii) bringing together end portions of a piece of extruded core and sheath to form a ring,(iv) effecting crosslinking of the extruded core, and(v) effecting crosslinking of the extruded sheath.

Abstract: A closure system including a cap and a container, the cap including a top wall, a depending skirt having a bottom end and an annular projection integral with the bottom end of the skirt and having a curled free end portion which has grooves formed by threads in the neck when the cap is pressed on the container in sealed relationship.

Abstract: A method is disclosed for forming a net-like structure from a suitable material, such as metal or a synthetic polymer. The structure avoids the problems of low tear strength at the joints in the mesh and enables novel shapes and designs to be formed that are not possible to make by other methods. The method comprises the steps of forming a planar web from a suitable material in a plastic state, the forming providing for the planar web to have a substantially flat parting plane, the planar web having an expandable pattern of strands and strand joints with apertures therebetween, and expanding the planar web by forcing the exterior and interior of the web apart in a direction generally perpendicular to the planar web, to form a three-dimensional net-like structure.

Abstract: An electrically insulating formed channel member is made of a sheet of an electrically insulating material capable of being press formed that is cut to provide radially projecting portions. Thereafter, the sheet is press-formed to form a formed channel member including the channel portion and the projection portions and bent to extend along the inner corner of a rectangular pancake coil with the web located at the inner side of the corner curvature. The sheet material may preferably be a dray paper press board. Ripples may be provided in the sheet material prior to the step of press-forming. The moisture in the sheet material may also be adjusted prior to the step of press-forming.

Abstract: In combination, a container and a linerless cap and a method of forming the cap. In the method the cap is molded from plastic and includes a top well, an outer depending skirt and an internal depending substantially annular wall having an upper end integral with and depending from the top wall and a lower free end. Thereafter the free end is engaged by a curling tool to progressively turn the free end away from the internal wall to curve the free end into a curvilinear compressible and resilient free end adapted to be engaged for sealing. The engageable free end of the seal can have a coil, O, U, J or quarter round cross sectional shape and can be a rim, plug or corner seal.

Abstract: A method of forming a selectively expansible pocket or bulge in a thin plastic sheet to facilitate the use of the sheet as a surface protector or shield includes the step of applying oppositely directed forces to the sheet in a plurality of intermeshed closely spaced lines about a predetermined area in which it is desired to form a pocket. The forces are applied until stretching, thinning, and permanent deformation of the sheet takes place along the lines to produce a plurality of permanent corrugations to permit lateral deflection of the predetermined area.

Abstract: A continuous length of transparent plastic rod is fabricated into meaningful letters, numbers, or other shapes wherein the meaningful portions are coated with a pigment and/or reflective substance leaving the portions or spaces between meaningful portions transparent and not readily visible, whereby the structure as a unit resembles a neon sign.

Abstract: A method for manufacture of a sealing ring with a flanged sealing lip having hydrodynamically acting return transport properties in which a sealing lip is first generated by extrusion of a plastically deformable material through a ring nozzle having rotating inner and outer surfaces which are rotated relative to each other to impart a helical motion to the extruded material; the hydrodynamically acting return transport properties being a microscopically fine pleating of the surface of the extruded hollow cylinder. The extruded cylinder is then solidified and cut to a predetermined length. The cylinder is then widened in the radial direction at its front end by an assembly tool which shapes the cylinder into a trumpet-shaped sealing ring with a flanged sealing lip.

Abstract: In a method for manufacturing a sealing ring with a sealing lip, the material forming the sealing lip is fabricated in plastically deformable condition into the shape of a column-like hollow body. Prior to solidification, the column-like hollow body is twisted between axially spaced cross-sectional planes. This forms return elements with hydrodynamic action. Subsequently, the hollow body is solidfied and its diameter is enlarged axially outside the region of the sealing lip and it is then secured in a sealing ring housing.