Abstract: An apparatus for the manufacture of profiled plastic pipes comprises a machine bed (1) that half shells (2, 2′) are guided on, forming a molding path (9). A driving pinion (17) is provided above the molding path (9). At least one lower driving pinion (41) is provided on the machine bed (1) along the molding path (9). A lower indentation (39, 39′) is formed in the area of the lower side (30, 30′) of the half shells (2, 2′), with the at least one lower driving pinion (41, 41′) engaging therewith.

Abstract: An improved blown film extrusion apparatus is provided. The apparatus includes an annular die for extruding a film tube. At least one tube position transducer is provided and located adjacent to the extruded film tube. The tube position transducer transmits interrogating pulses to the extruded film tube and produces a position signal corresponding to a detected position under the extruded film tube. A bubble position control system is provided for receiving and processing the position signal. A valve is provided for varying a quantity of air within the extruded film tube in response to the bubble position control means. This urges the extruded film tube to a desired position. The apparatus further includes a collapsing frame assembly for receiving the extruded film tube and collapsing it. The collapsing frame assembly includes several frame boards. Typically, two opposing main boards and two opposing side boards are provided.

Abstract: A candle wick die plate includes an aluminum subframe with a split stainless steel die station. The die station has a lower member and a plurality of removable upper members. The die holes are aligned with their diameters collinear with the division between the upper members and the lower member. According to the presently preferred embodiment, each upper member is associated with a single die hole, half of which is defined by the upper member and the other half of which is defined by the lower member. Each upper member is preferably provided with an insulated handle and the lower member is preferably provided with a plurality of clamps for clamping the upper members in position. The upper and lower members are preferably provided with mating pins and holes for rapid alignment.

Abstract: An apparatus for folding a catheter balloon comprises a stationary base member; a rotatable drive hub which is moveable in relation to the stationary base member; and a pleating head aligned with respect to the stationary base member and to the rotatable drive hub. The pleating head includes at least three segments, each having a proximal end and an angled distal end with at least one angled side face terminating in an edge of a predetermined length. Each segment has a centerline between the proximal and distal ends, each segment having a proximal point and a distal point, and the proximal point being pivotally coupled by pins to the stationary base member and the distal point being pivotally coupled by pins to the rotatable hub member. The segments are arranged so that the segment distal ends are disposed adjacent to and a predetermined distance away from a central point and defining a central aperture with a spiral-pleat dimension having at least three channels in communication with a central aperture.

Abstract: A roller guide (9) for extrusion calibrators (1) of tubular plastic films (7), provided with a surface removable and interchangeable sleeve (10) made from materials having high thermal insulation characteristics and a good surface friction (grip) coefficient. Such characteristics allow a regular flow of the film being extruded (7) and a uniform cooling thermal dispersion throughout the surface development of said films.

Abstract: Apparatus for forming a bell mouth on a pre-heated pipe includes a first portion with means for moving the first portion from a first position to an expanded position. Means for heating the first portion to a temperature at least equal to the pipe pre-heat temperature are provided. A second portion is geometrically fixed and includes an outer diameter that is equal to the final inner diameter of the bell mouth. The outer diameter of the second portion is less than the outer diameter of the expanded first portion. Means are provided for cooling the second portion. A third portion includes a hollow rubber element that is expandable, from a first diameter less than the starting inner diameter of the pipe to a second diameter between the first diameter and the outer diameter of the expanded first portion.

Abstract: An apparatus for the manufacture of corrugated plastic pipes comprises half shells. Each half shell has a base body which consists of a metal of a higher thermal conductivity and a lower specific gravity than steel and which holds a core. Provided in the core is a mold recess in which to form the corrugated pipes.

Abstract: A method and an apparatus for the manufacture of pipes of thermoplastics with transverse profile features comprises mold segment halves which are circulated by twos on a molding path. A conveying device of the type of a gantry crane is provided for recirculation of the mold segment halves. On a conveying bridge that bridges the molding path, provision is made for two conveying carriages, which are movable in opposite directions and crosswise of the direction of production and which have mounted on them a downward conveying arm with a holding device for a respective mold segment half. Provided downstream of the downstream end of the molding path are parking positions for additional mold segment halves, those of which that are closest to the molding path being carriages which are movable out of the path of displacement of the conveying arms.

Abstract: Methods and apparatus for the processing of a continuous blown film undergoing collapsing in which a plurality of differential elements of the film follow respective streamline paths which are approximately equal in length to the path of the longest streamline thereby substantially equalizing circumferentially varying shape change induced machine direction stresses and reducing the residence time variations within higher thermal energy regions so as to significantly minimize the commonly rather large magnitudes of variations of gauge, energy to break and machine direction lengths of the solidified material. The method and apparatus provide the potential to structure more uniformly the macromolecular arrangements existing within the material and allow the blown film extrusion of higher modulus materials than have heretofore been possible.

Abstract: A corrugator and mold management apparatus and methods for continuously forming transverse corrugations and other shapes in a tubular polymer melt parison formed by an extrusion die employs a plurality of molds that interlock when mated. Each mold has common outside dimensions and a pair of open linear bearings that provide the mold axis and maintain alignment of the molds parallel to and in the same horizontal plane as the axis of the extrusion die. The molds are moved axially along supported rails by bi-directional linear actuating modules and between the pairs of supported rails by lateral transport units. Inner supported rails define the mold tunnel and outer supported rails provide an outer path to move molds upstream back toward the extrusion die. The lateral transport units include extensible rails that facilitate the transfer of molds to and from the mold tunnel and the outer return paths. Delivery units remove from and introduce molds from a plurality of parking stations.

Abstract: A method for treating a roller cover includes the steps of positioning an element with respect to a roller cover and removing a portion of the roller cover with the element to form a pattern on the roller cover. The process for treating roller covers for a paint roller may also include the steps of providing a surface, forming a pattern on the surface, heating the surface, and contacting the roller cover with the heated surface. The heated surface is a metal. The heat is transferred from the heated metal surface to the roller cover when the heated metal surface contacts the roller cover. The heated surface sears or melts the nap of the roller cover. The surface can be provided with a pattern so that a pattern can be placed into the nap of the roller cover. An apparatus used to treat the surface of a roller cover includes a surface having a desired pattern therein. A holder for a roller cover holds or presents the roller cover to the surface. A heater is attached to the surface.

Abstract: A method and apparatus are described for making an article such as the body of a needleless injector capsule, from a formable material, such as glass, the article having a cavity communicating with the exterior via an orifice. A blank having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool while an end region of the blank adjacent the open end is in a condition to permit it to be formed. One of the tools has a pin extending therefrom, and when the tools are brought together to form the end region into the desired shape the pin defines the orifice.

Abstract: A take-off apparatus for plastic blown sheet that is collapsed has a deflecting roller rotatably mounted for transporting the blown sheet and an air turning bar for receiving the blown sheet from the deflecting bar along a transport plane defined therebetween. The blown sheet passes around a peripheral portion of the air turning bar thereby defining a support arc region of the at least one air turning bar about which the blown sheet is supported. The air turning bar has air outlet openings disposed in the support arc region through which compressed air is ejected to support the blown sheet. The air turning bar has an arc-shaped axis defining a plane of curvature which is oriented such that the peripheral portion presents a concave surface in which the air outlet openings are disposed and which opposes the blown sheet.

Abstract: A molding machine including a plurality of carriages for carrying mold blocks in an axial direction. The carriages each include wheels on opposite sides which follow a guide track along an endless path including a molding section extending in the axial direction. Two wings are secured to the carriages for pivoting about an axis extending in the axial direction whereby in one pivotal position the mold blocks are together in a molding position and in another pivotal position the mold blocks are separated in a releasing position. Each of the wings is adapted to carry one of the mold blocks and has a flat axially extending surface and guide wheels. A wing guide track engages the wing guide wheels and is adapted to place the wings in the molding position when the carriage is in the molding section. A first set of track rollers along the molding section engages the flat axially extending surface of one of the wings of carriages in the molding section along a first rolling plane extending in the axial direction.

Abstract: A method of manufacturing a plastics material bellows, wherein a preform is made by molding plastics material in a mold, the mold having preferred deformation zones, and then before the part has completely left the mold, the bellows is formed by folding the preform in the preferred deformation zones, with the resulting bellows being open at both ends.

Abstract: The apparatus for connecting objects by means of a plastically deformable connecting body comprises a shaping punch (4), a flow-restricting wall (5) closely surrounding the shaping punch and a gas supply lead (6) through which a gaseous medium can be introduced into the gap between the shaping punch (4) and the flow-restricting means (5). The shaping punch (4) has a heating cartridge (8) by means of which the lower end of the shaping punch can be heated. Provided on the outside of this shaping punch are heat-transfer ribs (9) which are used to heat up the supplied, gaseous medium which emerges at the lower end of the flow-restricting means in order to produce a flow around a plastically deformable connecting body (3), so that the latter is uniformly heated for the deforming process. The connecting body (3) is also integrally formed on a part (2) and reaches through a hole in a second part (1) which is to be connected to the first part.

Abstract: A method and apparatus for bending thermoplastic tube in which a pre-heated region of the tube is conformed to a required bend configuration while supported internally and externally to prevent the tube wall collapsing. The external support is provided by relatively movable formers which enclose a section of the tube at the point where the bending force is applied and this enclosed section moves progressively along the heated region as the bend is developed by the relative movement of the formers. The internal support is provided by fluid pressure higher than atmospheric pressure within the tube during the forming operation. Multiple bends can be formed sequentially and/or siitultateously.

Abstract: An apparatus for heat staking utilizes an infrared lamp to direct radiant energy onto a plastic part to heat and so soften it prior to the staking punch impacting the part. The apparatus comprises an energy directing means for concentrating the infrared energy onto the part, and a moveable carriage for moving the punch toward and away from the part. One embodiment of the energy concentrating means is a reflector, wherein the reflector includes a central aperture for admission of the part, and wherein the reflector comprises different curved sections for concentrating the energy over the surface of the part. In an alternate embodiment, the energy directing means comprises fiber optic cables for directing the infrared energy to the surface of the part.

Abstract: The machine of the present invention is a means for manufacturing thermoplastic tubes from hollow thermoplastic sleeves by a variety of different manufacturing processes. The machine is a single apparatus having an indexing table with a plurality of mandrels for holding hollow thermoplastic sleeves for the purpose of transporting the same around a closed manufacturing path. The manufacturing path of the machine of the present invention is a series of stations which are mechanical devices for carrying out the manufacturing steps necessary to produce tubes from thermoplastic blank sleeves. The stations of the manufacturing path are modular so that they may be removed, added or rearranged; may be optionally connected to a process logic controller and may optionally have sensors for information feedback to the PLC device.

Abstract: The machine of the present invention is a means for manufacturing thermoplastic tubes from hollow thermoplastic sleeves by a variety of different manufacturing processes. The machine is a single apparatus having an indexing table with a plurality of mandrels for holding hollow thermoplastic sleeves for the purpose of transporting the same around a closed manufacturing path. The manufacturing path of the machine of the present invention is a series of stations which are mechanical devices for carrying out the manufacturing steps necessary to produce tubes from thermoplastic blank sleeves. The stations of the manufacturing path are modular so that they may be removed, added or rearranged; may be optionally connected to a process logic controller and may optionally have sensors for information feedback to the PLC device.

Abstract: There is provided a plastic working machine for plastically working a tube by employing tube holding and spinning means for holding and spinning the plastically workable tube around the axis of the tube and first and second plastic working tools which face to each other so as to pinch the tube in the radial direction of the tube and which are movable along the radial and axial directions of the tube while being pressed against the tube. The plastic working machine executes a step of plastically working the tube by the first and second plastic working tools by continuously spinning the tube around the axis thereof and by applying compressive load or tensile load along the axial direction of the tube to the tube.

Abstract: Method and apparatus for sequentially forming, wrapping and compressing a catheter balloon either during the initial manufacturing process or after a medical procedure. The balloon may be formed, wrapped and compressed by simply advancing the balloon through a balloon wrapping tool and selectively inflating and deflating the balloon therein. The balloon wrapping tool preferably includes a flap forming bore, a flap wrapping bore and a flap compression bore which form, wrap and compress the balloon, respectively, when the balloon is advanced therethrough.

Abstract: The invention provides apparatus and a method for forming a bend in a linear section of thermoplastic pipe. The apparatus comprises an anvil having a concave working surface which defines an arc of at least the bend angle of the bend to be formed in the pipe section and which is transversely arced at a radius essentially the same as the radius of the pipe, the anvil further including a collar for retaining an end of the pipe section adjacent the working surface.

Abstract: Described is an apparatus for the production of transversely ribbed tubes, having mold jaw halves which bear against each other along a common mold section and form a mold passage. Each mold jaw half has a cooling passage which is produced directly during the operation of casting the respective mold jaw half, for example by means of a so-called false casting core. The cooling passage extends in the corresponding mold jaw half from a first surface to a second surface so that said core can be easily removed from the casting of the mold jaw half. At the one surface, the cooling passage has a cooling agent feed means and, at a spacing therefrom, a cooling agent discharge means. The second surface which is at a distance therefrom is sealed off by means of a guide and slide element which is fixed to the corresponding mold jaw half.

Abstract: Process and apparatus for bending thin-wall thermoplastic tubing utilizing pressure inside the tube portion being bent to thereby maintain the shape of the tube during bending, and applying heat only in the zone of the tube that is stretched by pulling it axially during continuous incremental bending around a rotatable bend die to thereby maintain the original cross-sectional shape of the tubing. The tube inside radius surface is continuously supported during application of bending-induced tensile stress by causing the tube to track or wrap partially around a rotatable bend die in a generally linear (minimum slip) tracking mode.

Abstract: A head for use in a heat staking machine utilizes an infrared heat lamp and reflectors to direct radiant energy onto a plastic stud to heat and so soften it prior to the staking punch impacting the stud. The lamp is disposed within a parabolic primary reflector which directs the lamp's output toward a secondary reflector. The secondary reflector has is concave and has a central aperture at its vertex through which the stud projects such that all of the radiant energy emitted by the lamp is focussed radially inward onto the stud. The punch is slidably mounted to the primary reflector for reciprocal movement along the axes of the reflectors, and is extended to impact the stud.

Abstract: Apparatus for sequentially forming, wrapping and compressing a catheter balloon either during the initial manufacturing process or after a medical procedure. The balloon may be formed, wrapped and compressed by simply advancing the balloon through a balloon wrapping tool and selectively inflating and deflating the balloon therein. The balloon wrapping tool preferably includes a flap forming bore, a flap wrapping bore and a flap compression bore which form, wrap and compress the balloon, respectively, when the balloon is advanced therethrough.

Abstract: The present invention relates to an apparatus for the extrusion of plastic profiles with an extruder having an extruder flange, an extrusion die with a die flange through which the extrusion die is detachably connectable with the extruder flange, a fastening element with the two halves which is arranged to embrace the extruder flange and the die flange, a tensioning element in order to press the two halves of the fastening element against the flanges. An improved function is achieved in such a way that the two halves of the fastening element are fastened swivelably on the extruder and that they are mechanically coupled in order to perform an oppositely directed swiveling movement.

Abstract: An apparatus and method for forming a bend in a thermoplastic tube including a fixture having a former with a bend. A clamp holds the tube in place while an upper form and lower form sandwiches the tube therein. Infrared lights are positioned against the bends of the upper and lower forms. The upper and lower forms are made of a Teflon material to allow the infrared wavelengths to flow therethrough and heat only the bend of the tube. Another embodiment includes a hollow box having a top surface with a groove formed therein to correspond to the desired shape and bend of the tube. Along the bend portion of the groove are slots. The hollow upper box is connected to a solid lower box having air intake holes therethrough to the hollow interior of the upper box. Cold or hot air enters through one of the intake holes and is directed through the slots to the bend portion of the tube.

Abstract: The invention relates to an apparatus for cooling and calibrating extruded plastic profiles with a trough which is provided downstream of a dry calibrating device and has a water bath through which the profile is guided, with plates being arranged in the trough between the face walls in order to calibrate the profile under the influence of negative pressure. In order to achieve a high production speed with a low amount of expenditure it is proposed that a sleeve encompassing the profile is provided in a section of the trough, which sleeve guides at least in a zone of the main body of the profile and that the sleeve is provided with a distance to the face walls in the longitudinal direction.

Abstract: Take-off equipment for tubular sheets are provided for plastic film produced by an extruder with a stationary blowing head. Collapsing boards collapse the tubular sheet with expanded circular cross section, and stationary conveying equipment transports the collapsed tubular sheet to stationary wind-up equipment. A reversing system with at least one deflecting roller and at least one turning bar is pivotably supported between the collapsing boards and the stationary conveying equipment. The reversing system includes at least two turntables which are at a distance from one another vertically corresponding to the at least one deflecting roller and the at least one turning bar. The turntables lie with their centers in a central vertical axis of the equipment and can be driven in a reversing manner each over a planet wheel to different turning angles. The planet wheels are constructed in each case as open planetary gears with the associated turntable having a sun wheel.

Abstract: The present invention provides a profiling process which allows for the material sheet to be profiled so that the surface is minimally affected and only slight plastic deformation of the material occurs, and yet uniform three-dimensional structuring takes place. Additionally, the present invention allows for an improved inherent stability in the plane of the profiled material sheet to be achieved while only minimally affecting the cross-section.

Abstract: An apparatus for conferring a cup shape to the terminal junction segment of pipes that are bi-axially oriented longitudinally and circumferentially and hence very sensitive to diameter and length reduction through heat. The apparatus includes a furnace which heats the segment to a differentiated temperature, increasing towards the end of the segment such that the inner diameter of the terminal segment progressively drops down to a controlled value as temperature increases (whilst length is simultaneously reduced, with a corresponding increase in thickness of the wall of the terminal segment). Preferably then, in an appropriate station, an additional heating is executed to a plastic deformation temperature suited to obtain a correct preliminary dilation of the terminal segment upon introducing a rigid element which acts as inner contrast, thereby inhibiting any retraction thereof.

Abstract: A method and apparatus are described for making an article such as the body of a needleless injector capsule, from a formable material, such as glass, the article having a cavity communicating with the exterior via an orifice. A blank (1a) having an open end is mounted on a first forming tool, and the open end is engaged by a second forming tool (22) while an end region of the blank (1a) adjacent the open end is in a condition to permit it to be formed. One of the tools (7a) has a pin (21) extending therefrom, and when the tools are brought together to form the end region into the desired shape of the pin (21) defines the orifice.

Abstract: According to the invention thin sheets of foil are stiffened in a particular way by means of vault-structuring. The vault-structuring occurs either by self-organizing or following a self-organized design with a spade-shaped or drop-shaped pattern.

Abstract: The present invention relates to an apparatus for producing pipes of a moldable material, preferably plastic, comprising an extruder, a cylindrical mold comprising chill molds (4, 5), a mandrel (8) inside the extruder and a kernel (9) as an extension of the mandrel. The mandrel is attached at its front end to the extruder. The mandrel (8) and the kernel (9) can be kept concentric with the extruder and the mold if the mandrel and the kernel are joined to each other in such a manner that the angle between their center lines is adjustable.

Abstract: A bending table upon which lengths of plastics material rendered flexible by heating, may be set to determine a desired curvature thereof, particularly for producing arched UPVC window and door frames, the table including an unslotted ferro-magnetic top (1) and a plurality of bobbins (3) each mounted at the end of a radially extending arm (6,7) the arms being mounted upon independently rotatable spindle members (4) such that the angles subtended by each adjacent arms (6,7) is adjustable and wherein the spindles (4) are themselves may be positioned selectively along a locating strip (16) fixed to the table top. Further arms (17) are adjustable along the strip (16) and extend transversely across the table top to support one or more fences (18). The table enables an arched profile (32) having, if required, straight sections, to be produced to any desired shape, and the magnetically attractive bobbins (3) retain the positions of the arms but can be readily adjusted to suit any desired profile.

Abstract: Described is an apparatus for the production of transversely ribbed tubes, having mold jaw halves which bear against each other along a common mold section with front faces and form therebetween a mold passage. Each mold jaw half has vacuum passages which are in flow communication with the mold passage. Each mold jaw half also has a cooling passage (22). The front faces of the mold jaw halves are formed with vacuum communication channels which, along the common mold section, form vacuum communication passages. The vacuum communication passages are in flow communication with a stationary vacuum rail, along the common mold section of the apparatus. Along the common mold section, the cooling passages of the mold jaw halves are in fluid communication with a stationary cooling agent rail which has a cooling agent feed means and a cooling agent discharge means.

Abstract: An apparatus for embossing a cylindrical object such as a paint roller cover. The apparatus includes a shuttle and a rotatable shaft on the shuttle. The rotatable shaft includes two ends, with one end accepting a paint roller cover and with the other end being toothed for engagement with a gear rack. As the rotatable shaft is drawn in one direction by the shuttle, the toothed end engages the gear rack and rotates the rotatable shaft, thereby also rotating the paint roller cover. As the paint roller cover rotates, it is drawn by the shuttle over a die transfer plate having a design formed therein, and such design is transferred to the paint roller cover. The die transfer plate is heated to the desired temperature, and the speed of the shuttle is controllable so that time and temperature is controlled. Another controlled parameter is pressure. A method for embossing cylindrical objects is also disclosed.

Abstract: An external stabilizer employed in a plastic film blowing apparatus stacks of swing arm members that create an iris aperture for the extruded film bubble. A tubular die, fed with a supply of molten thermoplastic polymer, extrudes a tube of the molten polymer and injects air into the extruded tube to inflate the tube into a bubble. The wall of the tube expands into a film of a desired thickness; and the tube is drawn vertically upward and collapsed and flattened. The external stabilizer has a frame surrounding the extruded tube above the die. A plurality of swing arms arranged on said frame define the iris aperture. Each of the swing arms is an elongated extrusion of a light-weight material having one end mounted pivotally on the frame and a free end. The swing arm has a mushroom-shaped profile that is rounded on a side that faces the extruded tube. Wear resistant material is disposed on the front surface.

Abstract: A molding machine including a plurality of carriages for carrying mold blocks in an axial direction and a track for the carriages including a molding section, the track including spaced apart channels receiving the carriage wheels for guiding the carriages along the track. The carriages each include wheels on opposite sides of the carriage, a first set of oppositely facing and axially extending flat surfaces on one side of the carriage, a second set of oppositely facing and axially extending flat surfaces on the other side of the carriage, and centering rollers having facing rolling surfaces spaced apart a distance X. The track includes first and second sets of track rollers associated with one of the channels, the first and second track roller sets defining a first pair of axially extending, parallel facing rolling planes whereby the first and second roller sets engage the first set of flat surfaces of carriages in the molding section.

Abstract: In combination with a mixer/extruder of the type designed to mix, heat and extrude a mixture of shredded plastic material and shredded fibrous material, the heated mixture being extruded in the form of a continuous beam from an extrusion nozzle, the improvement which comprises a first matrix spaced horizontally downstream from the nozzle for receiving the beam therein and a second matrix spaced horizontally downstream from the first matrix for receiving the beam therein, the first matrix having a plurality of moveable walls which reciprocate in a horizontal direction against the outer surface of the beam, the second matrix having a plurality of moveable walls which reciprocate in a horizontal direction against the outer surface of the beam, the second matrix having means for conducting cooling water therethrough for cooling the beam as it passes through the second matrix.

Abstract: A method and apparatus for forming a flanged polytetrafluoroethylene cuffed section from a tubular polytetrafluoroethylene graft. The flanged polytetrafluoroethylene graft is well suited for use as a distal bypass graft, for arteriovenous grafting, or as a hemodialysis access graft. The graft includes an integral terminal polytetrafluoroethylene flanged skirt or cuff section which facilitates an end-to-side anastomosis directly between an artery and the polytetrafluoroethylene flanged graft without need for an intervening venous collar or venous patch.

Abstract: A rubber composition containing 20 parts by weight-200 parts by weight of hydrogenated styrene thermoplastic elastomer and poly-olefin for 100 parts by weight of rubber which is dynamically vulcanized with a resin vulcanizing agent to disperse the rubber in a mixture of the hydrogenated styrene thermoplastic elastomer and the poly-olefin.

Abstract: The invention relates to a system for preforming an extruded plastics parison including a nonplanar conveyor belt. It also relates to a method for preforming an extruded parison, including a step during which the parison is deposited on a conveyor belt. The conveyor belt is not planar. This step may be accompanied by a step in which the parison undergoes transverse deformation. The invention also relates to a method of manufacturing at least one article, including such a preforming step.

Abstract: A curling screw adjustment mechanism for changing the radial spacing of the curling screws of a lip curling machine forming a lip on a thermoformed plastic container such as a cup, in which the curling screws are each mounted on separate interlinked pivoted mounting plates which are moved in unison by adjustments of a threaded rod. The curling screws are also cooled by indirect contact with a cooling liquid circulated through separate aluminum arbors on which the stainless steel curling screws are mounted to allow changing the curling screws without spillage of coolant.

Abstract: A method of manufacturing a balloon portion for a balloon catheter for radially expanding a vessel in the body of a mammal, which catheter comprises a tube portion with a passage therethrough and a hollow expandable balloon portion defined by a fluid impervious wall and secured to the tube portion, which balloon portion can be inflated and deflated by means of a fluid passed through the passage, such that:a. the wall of the balloon portion is formed from a flexible substantially fluid impervious material having re-inforcing fibers formed integrally with the wall material; andb. the balloon portion is preformed to the desired radial diameter at its inflated state having smaller diameter end portions and a wider diameter portion intermediate the said ends and has a substantially uniform wall thickness.

Abstract: A pipe molding apparatus for forming double walled plastic pipe comprises an extruder which feeds first and second parisons of flowing plastic material to a moving mold tunnel to make respectively the outer and inner walls of the pipe. The moving mold tunnel includes a cooling plug over which the second parison moves to form the inner pipe wall while the outer wall of the pipe is formed against the interior surface of the mold tunnel. An air assist is provided internally of and helps to move the inner parison onto the cooling plug.

Abstract: A method of expanding a tube of plastics material in which a longitudinally travelling tube is progressively diametrically expanded in internal fluid pressure in an expansion zone between an upstream plug and an expandable downstream plug. Expansion of the tube is controlled in response to parameters which directly or indirectly indicate variation in the relative velocity at which material is delivered to and removed from the expansion zone, such as detecting upstream velocity, early expansion diameter, axial force on a sizing device or the tube diameter just before the expansion zone.

Abstract: Described is an apparatus for the production of transversely ribbed tubes, having mold jaw halves which bear against each other along a common mold section with front faces, and form a mold passage. Each mold jaw half is connected at a surface to a support element. The support elements are guided along a first linear guide device. A guide and slide element is fixed to a second surface of each mold jaw half. The guide and slide elements are guided along a second linear guide device. The support elements and the guide and slide elements comprise the same material. The mold jaw halves comprise a material of relatively low specific weight and a coefficient of thermal expansion (.alpha..sub.B) which is high in comparison with the coefficient of thermal expansion (.alpha..sub.A) of the material for the support elements and the guide and slide elements.