Abstract: An extrusion die having an extrusion slit defined by two lips one of which is flexible. A plurality of thrust members are disposed very close to one another and bear against the flexible lip. A drive motor is individual to each thrust member for rotating each thrust member to move the flexible lip toward or away from the other lip. A universal joint directly connects an output shaft of each motor to its respective thrust member. The output shafts are at oblique angles to their respective thrust members and some of the output shafts are disposed at substantial angles to others of the output shafts, whereby the motors are staggered.

Abstract: An apparatus for shaping a spherical body consisting of dough crust and a filling is provided. A continuously fed cylindrical body, consisting of dough crust and a filling, is constricted by at least three slidable members which form an opening or closes it. The members slide on each other so as to constrict the cylindrical body. The contact area of the members with the surface of the cylindrical body gradually decreases as the opening is closed, thereby constricting the cylindrical body and shaping the spherical body.

Abstract: The apparatus includes a crosshead and die assembly for the extrusion of polymeric resins and the like into tubular shapes, for example, of single or multiple layers. A crosshead body has a side fed resin inlet orifice which communicates with a first resin distribution channel extending 180.degree. around an inner mandrel, the first channels having gate orifices at the ends thereof. The gate orifices feed heated resin to a second resin distribution channel which extends 360.degree. around the mandrel and communicates with a first restrictive annular opening which also extends 360.degree. around the mandrel. The first restrictive annular opening feeds resin to a third resin distribution channel which also is formed 360.degree. around the mandrel. A second restrictive annular opening communicates with the third resin distribution channel 360.degree. around its circumference and feeds the molten resin or the like to an annular opening formed between the inner mandrel and the crosshead body.

Abstract: The shaping device, particularly for an extruder tool or calibrator unit, for an extruder for thermoplastic material comprises at least one outlet defining an adjustably positionable unit lip, an opposing lip and at least one positioning member acting on the unit lip which is a part of a control and/or regulating mechanism for the thickness of the extruded product. The positioning member is a piezoelectric translator connected to a voltage source having a plurality of piezoelectric disks positioned opposing each other which are combined in a plurality of groups according to operation and according to electrical circuitry considerations. The groups of the piezoelectric disks individually and the sum total of several of the groups including the group containing all of the piezoelectric disks are connectable to the voltage source.

Abstract: Extrusion molding equipment for a multi-layer parison which includes an accumulator head, a cylindrical member disposed in the accumulator head and having a temperature control device for controlling a chief resin material temperature wise, a ringed piston reciprocable along the inner peripheral surface of the cylindrical member, a core member coaxially disposed inside the ringed piston and at least one ringed member coaxially disposed within an annular resin passage defined between the cylindrical member and the core member, into which resin passage the chief resin material is forcibly supplied from an accumulator composed of the ringed piston and a hydraulic cylinder operating the ringed piston, with one or more annular nozzles being defined in the ringed member for extruding one or more auxillary resin materials.

Abstract: An extrusion die for externally ribbed seamless plastic tubing, including an extrusion head with an elongate nozzle within which a hollow mandrel is placed. The nozzle and mandrel define an annular extrusion orifice forming a parison of the tubing and having a coaxial conical portion with its generatrix forming an angle of substantially more than 45" with the longitudinal axis of the head, the diameter of the mandrel at its delivery end being not less than that of the nozzle. The die can be supplied also with an electrical heater incorporated inside the mandrel after said orifice, with a centering means mounting said nozzle uniformly spaced around the mandrel, with a threaded member for adjusting longitudinally said mandrel to vary the size of the extrusion orifice, and with a coupling means interconnecting said mandrel and the head and allowing only the axial, without rotation, movement of the mandrel.

Abstract: Apparatus for forming an insulation layer around an electrical conductor and having a die insert or core tube for guiding the conductor through a die orifice. The insert is movable to control its position and its position is controlled by two rotatable mountings. A first of the mountings eccentrically holds and is rotatable around the insert while the second mounting lies radially outside of and eccentrically holds the first mounting. A monitoring means analyzes degree of eccentricity of the conductor and operates a driving means for the mountings to move the insert in the appropriate direction for concentricity.

Abstract: Extrusion apparatus for conductor wire in which a core tube for guiding the wire is controllably movable axially so as to adjust the cross-sectional area of the flow passage for molten polymeric dielectric material moving towards the die orifice. The use of the adjustable core tube minimizes the degree of draw down of the conductor wire.

Abstract: A T die for extruding a low viscosity resin film coating especially in the manufacture of adhesive tapes. Uniform extrusion from the die is accomplished by the flow of melted resin from a supply manifold through a large number of narrow passageways into a smaller pressure equalizing manifold and out of a die slit extending the entire width of the die, the width of the die slit being adjustable in order to regulate the unevenness of the yield product.

Abstract: A T-die adapted for extrusion molding of a plastic material such as plastic film is constituted by a lower stationary half and an upper movable half. The stationary half is integrally provided with a steady lip portion and a movable half is provided with a base portion and flexible lip portion so as to form a gap in slit form between the steady and flexible lip portions. The gap is adjusted partially by a plurality of adjusting bolts screwed to the upper portion of the movable half extending to cover the flexible lip portion with space, the bolts being arranged in a line along the longitudinal direction of the T-die and spaced equally with each other. Each bolt has such a length that the front end thereof downwardly presses the flexible lip portion when the bolt is driven downwardly. The flexible lip portion is provided with a plurality of U-shaped grooves each disposed between the adjacent two bolts and having a width of an opening substantially equal to the distance between the adjacent two bolts.

Abstract: A nozzle permits extrusion of an outer, expanded dough layer having two filler materials co-extruded therewith. An adjusting mechanism is provided for precisely locating two filler injection conduits with a surrounding guide nozzle. A pillow-shaped final product is formed, having an outer layer of expanded dough and two different filler materials.

Abstract: The apparatus for continuous extrusion of a plastic laminate has at least two extrusion screw presses, an accumulator block, a transition unit, and an output die, from which the plastic laminate product is extruded. The accumulator block has a combining channel or canal therein which is fed by the extrusion screw presses. This combining canal is connected by way of the transition unit to the output die. The combining canal preferably has a rectangular cross section with rounded corners and at its upstream end is directly connected to a first extrusion screw press by way of a connecting canal coaxial with the combining canal. Downstreamwards below the connecting canal is found at least one input metering slot connected to the combining canal at one end and through a connecting apparatus at its other end to an additional extrusion screw press, this input metering slot lying between an input plate and an adjusting bar guided in an adjusting bar recess.

Abstract: An adjustable feed block for a coextrusion die is provided. The feed block comprises a main central channel for conveying a main stream of molten thermoplastic material towards a coextrusion die, and at least one secondary channel, substantially parallel to the central channel, for conveying a second molten thermoplastic intended to form a local coating layer on the main stream. The downstream end of each secondary channel is inclined relative to the central channel and connected to a portion of the periphery of the said channel. The connection between the central channel and each secondary channel is laterally delimited by the ends of two adjustable slides which can be moved at right angles to the axis of the central channel. These slides make it possible to adjust, during operation, the position and width of the streams of thermoplastic deposited on the main stream.

Abstract: A method of manufacturing extruded pipes where plasticized material, for example plastic material, is advanced to an extrusion nozzle comprising a circular gap (2). The method is especially characterized in that the material is transported axially in said gap (2) while material is moved, for example rotated, in the circumferential direction of the gap (2) so that the material at least partially is caused to assume an orientation deviating from the axial direction, whereby a non-axial orientation will prevail in the extruded pipe (3) and increase the strength. The invention also relates to an apparatus for carrying out the method.

Abstract: A food extruding apparatus including a food receiving member having a through-hole receiving a food or a food material which is to be extruded and an extruding means inserted into the through-hole from one end thereof and moved toward the other end, thereby extruding the food or food material from the through-hole, the extruding means being constituted by outer and inner extruding members. After an extruding operation, these extruding members are not pulled back simultaneously, but the outer extruding member is first pulled back slowly, and then the inner extruding member is raised. There is therefore no fear of any vacuum being produced between the upper surface of a food or a food material and the extruding member when pulled back. Accordingly, it is possible to carry out a food extruding operation smoothly and properly.

Abstract: A discharge nozzle connected to the outlet of an extruder is built wedge-shaped in vertical longitudinal section and comprises a lower housing part and an upper housing part. The upper housing part is adapted to be swung open by being pivoted around a pivot axis, thus causing the nozzle to open. This opening of the nozzle occurs under the influence of a control and actuating member, as soon as a predetermined value of twisting moment, pressure or temperature is exceeded. The nozzle discharge opening has shutting locking bolts associated with it, adapted to shut off the discharge channels of the discharge opening of the nozzle. The discharge nozzle may be used to advantage for the continuous processing of electrode material.

Abstract: A multi-layer extrusion die comprising an integrate consisting of widening plates; each widening plate having respective flow passage for resin, the flow passage having inlet portion and downstream portion, the downstream portion being widened in the transverse direction and flat, a die body holding the integrate, and having a flat flow passage which combines outlets of the downstream portions, and a converter mounted on the inlet portion side of the integrate. The structure of the die is simplified and the cost becomes cheap.

Abstract: Apparatus for forming an insulation layer around an electrical conductor comprising an extruder head and a die insert within the head, the insert having a feedpath for the conductor towards the die orifice. An insert holder is provided and the insert is pivotally movable within the insert by the use of a flexible mounting means which allows for movement of the insert about any plane. The mounting means may be a flange with an annular weakened section to provide the flexibility. Alternatively, the mounting means comprises spring steel annular tubes disposed between the insert and holder.

Abstract: An extrusion die having pivotally mounted parts disposed at the die outlet and pivotal locking members for latching the pivotal parts closed.

Abstract: A dough guide is used to precisely control thickness of an expanding dough extrudate. The extrudate is forced through at least two vertical slots in an extrusion head, at relatively high pressure and at a temperature at least equal to the boiling temperature of water.The dough guide has three plates. A middle plate is fixed between the slots. Two movable plates are disposed on opposite sides of each slot from the middle plate. A threaded rod is used to selectively adjust the location of each of the movable plates. In alternative embodiments, any number of slots are used, each having two guides adjacent it. Any or all of the guides may be made selectively movable. A product called "crisp bread" may be made thereby.

Abstract: A T-shaped extrusion die for extruding films ofthermally flowable synthetic resin, comprising a manifold, a slot-like passage, lips, inner deckles for varying the edge thickness and width of the resulting extruded film and inner deckle rods for regulating the width thereof, the extrusion die characterized in that the inner deckles are each divided into upper and lower inner deckle portions for conveniently varying the width of the resulting extruded film and the inner rods are each provided at its tip with a tongue shaped protrusion for regulating the width of the resulting extruded film without forming edge beads at both edges thereof.

Abstract: A device for avoiding flow disturbances and stagnation during the production of hollow or solid multilayer elongate structures.

Abstract: An extrusion head is provided for extruding flat profiles for producing tread strip portions of vehicle tires from mixtures of rubber or plastics materials, which permits one of the constituents such as the tread strip mixture to be changed without adversely affecting the other constituent parts of the mixture, such as the lateral rubber strip mixtures and the base rubber layer. This is achieved by suitably deflecting the flow channels for the lateral rubber layers in a front template. The flow channel for the lateral strips enters the template below the flow channel for the tread strip but discharges alongside the lateral edges of the tread strip. The head comprises a fixed central portion and pivotable upper and lower portions, the flow channels for the constituents of the mixture being defined by channels formed in insert members located between the head portions.

Abstract: The block comprises a central channel (2) which feeds a first molten plastic, and at least one secondary channel (5, 10) which feeds a different molten plastic and connects to the central channel (2) upstream of the die, the central channel (2) in the connection zone, being equipped with a flat portion (11) which alters the cross-section of the channel, the said flat portion (11) being mounted in a removable piece (12) coaxial with the central channel and arranged in a guide tube (13) which intersects the central channel (2) and runs through the feed block (1), the said block being equipped with means (20), (21) for gradually withdrawing the removable piece (12) via the guide tube (13) and for replacing it by another removable piece (18) equipped with an identical or different flat portion (19).The block is particularly suitable for feeding a flat die which delivers films, sheets or composite panels.

Abstract: An extrusion head for producing profiles from different compounds comprises a body having a main fixed body portion with a plane forward face and two movable body portions which are pivotally mounted on the main body portion to pivot between a closed position in which they overlie the forward face of the main body portion and an open position. A short central channel leads from a central extruder to an extrusion die mounted in front of the forward face of the main body portion while flow channels formed between the forward face of the main body portion and the movable body portions lead from two side extruders respectively to the extrusion die. The movable body portions are moved between open and closed positions by hydraulic cylinder piston units which also hold the movable body parts in closed position during the extrusion process. Hydraulically operated clamping devices on the movable body parts releasably hold the extrusion die in position.

Abstract: A three station turret-type apparatus is provided with a first station including structure for receiving a quantity of soil to be compressed into a building block, a second station for compressing the soil into the desired building block and a third station for ejecting a formed building block from the apparatus. A rotary table is equipped with peripherally spaced sleeves for successive registry with the three station positions and each sleeve comprises a mold in which the desired block is to be formed. The sleeves are removable and replaceable and one form of sleeve is constructed to have an auxiliary smaller plan area sleeve removably mounted therein. Further in the second station position, a stationary bottom plate closes the lower end of the sleeve registered therewith and the bottom plate faced with a urethane elastomer material. A pressure head opposes and is movably toward and away from the stationary plate and is faced with a similar urethane elastomer material.

Abstract: An improved, low cost, energy efficient extrusion device and method for processing of cellulose- or fiber-bearing materials (e.g., wood chips, crop residues, whole or ground soybeans) is described which includes a transition screw section designed to smooth out material flow through the extruder and allow creation of increased barrel pressure and temperature levels. The transition section includes first and second alternating flights, with the depth of the first flight being less than that of the second flight and preferably gradually increasing until it equals the second flight depth. The overall extruder apparatus also advantageously includes a single flighted inlet screw section and a double flighted compression screw section respectively disposed on opposite sides of the transition section; in addition, the extruder has a pressure responsive adjustable die so that the effective dimensions of the die opening can be varied during the extrusion operation.

Abstract: Apparatus including an extruder, a die member and a vacuum device connected in series. The vacuum device includes a chamber and a device at at least the outlet thereof to air-tightly seal the chamber around the extruded mass of foamed thermoplastic resin. The air-shielding or sealing device is an annular tube which is inflatable radially inwardly having a flexible inner face which seals around the extruded mass. A durable, abrasion-resistant, flexible protective sheet can be interposed between the mass and the tube.

Abstract: In an extrusion process a feed conduit for the die is positioned axially in the extruder barrel to provide minimal surface roughness on the extrudate. Increased extrusion rates of quality product are obtained.

Abstract: A crosshead (10b) and a method are provided for extruding a tubular layer of a thermoplastic material, or for coextruding tubular layers of various thermoplastic materials, without incurring a weld line. The crosshead (10b) includes a supply passage (46) which provides an annular flow of thermoplastic material around a mandrel (18b) by providing separate flows that merge distal from a supply passage (52), a first compressive forging passage (72) that provides static mixing by transverse viscous shear, a longitudinal shear mixer (44a) that provides static mixing by longitudinal viscous shear, and a second compressive forging passage (94) that provides static mixing by longitudinal shear, and an extrusion opening (110).

Abstract: A die assembly for extruding multilayer parisons which is excellent in controlling the respective thicknesses of the resin layers of parisons and comprises a parison programming shaft; a core pin which is attached to the lowermost end of the parison programming shaft; a mandrel which encircles the parison programming shaft; a plurality of control rings which are mounted on the mandrel; a plurality of sleeves which are installed around the mandrel; a housing which holds the above members; a controlling member to control the resin quantity of the outer layer of parisons; a die supporting member; and a die; and characterized in that the resin passage of the die assembly is regulated by each of the control ring together with an annular rib that is formed on the inner wall of the sleeve; by the controlling member together with the lowermost sleeve; and by the die together with the core pin.

Abstract: A new and improved auger-type ice-making apparatus preferably includes at least a pair of removable and interchangeable head assemblies adapted for preselectively producing either relatively dry flake or chip ice, cube ice or smaller nugget-sized ice pieces. A new and improved auger assembly preferably formed from a synthetic plastic material and a new and improved evaporator element are also disclosed, either or both of which can be incorporated into an ice-making apparatus, with or without the interchangeable head assemblies.

Abstract: A nozzle assembly for extruding a tube has an outer housing sleeve having an inner surface centered on an axis and having an axially forwardly directed front end and a core formed of attached-together front, intermediate, and rear core ports. The front core part lies within the sleeve at the front end thereof and forms with the inner housing surface an annular axially forwardly open extrusion passage. The intermediate core part lies within the sleeve axially behind the front core part and is formed with a pair of grooves opening radially outward into the passage and each defined by a respective annular rear face extending generally perpendicular to the axis, a respective annular front face confronting the rear face and extending generally perpendicular to the axis, and a heart-shaped annular surface axially bridging the respective faces, facing radially forward, and having a portion forming a radially forwardly directed point.

Abstract: A worm press extruder or the like includes a worm shaft which conveys a flow medium within a housing cylinder. In order to provide the medium with an appropriate pressure and temperature the worm shaft cooperates with a constriction plate so as to define a gap therebetween. The gap is controlled by heat responsive unit e.g. a bolt of high thermal expansion coefficient which is connected to a stationary portion of the housing as well as to another housing portion which is movable with respect to the stationary housing portion by lever means. Consequently, when the temperature of the bolt is changed its length is altered thus causing the other housing portion which is associated with the constriction plate to shift towards the stationary housing portion. Since the worm shaft is supported by the stationary housing portion and cannot move axially with respect to the latter, the movement of the constriction plate causes a modification of the gap.

Abstract: A machine has a nozzle formed with an annular passage centered on an axis and having at an outer axial end an annular mouth. A plastic mass is introduced under pressure into the inner axial end of the passage at two diametrally opposite locations and mixes and passes outwardly along the passage to emerge from the mouth as a tube. The axial outward flow of the mass along the passage is impeded upstream of the mouth to pressurize the mass with a pressure substantially greater than atmospheric. Such flow is impeded either by restricting the passage or by allowing the volume of the passage to increase against a predetermined counterforce. The mass will form when it leaves the nozzle a tube of almost perfectly uniform wall thickness.

Abstract: An apparatus is disclosed for discharging material through an elongate aperture in a substantially constant amount per unit length of said aperture. The apparatus comprises a screw discharging unit having an inlet end and including a screw housing with a casing wall and a screw rotatably mounted in the screw housing. The elongate aperture is provided in the casing wall and extends substantially parallel to the axis of rotation of said screw. The screw has a core and at least one screw blade extending around the core and having a predetermined pitch for feeding the material from said inlet end to the elongate aperture. The core and said casing wall define therebetween a space having an annular cross section area successively decreasing in the direction of feed of the screw.

Abstract: In an apparatus such as a corrugator for manufacturing thermoplastic pipe with a corrugated outer wall and a smooth inner wall, a calibrator is employed to provide a smoother inner wall and a more rapid inner wall cooling. The calibrator includes a tube wound into a helical coil and an adjustment mechanism for adjusting the coil diameter. A cooling fluid may be passed through the tube.

Abstract: Extrusion apparatus with means to effect movement of a die insert. The die insert has an upstream extension with two planes of movement. For each plane of movement, two thrust means are provided, one at each side of the insert for movement in one direction in the plane. Each thrust means acts at an angle to the required direction of movement of the insert, and produces thrust which is inclined to the direction of movement of the thrust means. In one arrangement, two arms move together, one at each side of the insert extension and place thrust upon the extension. In another arrangement there is cam operation controlled by operating rings surrounding the extension. For movement in each plane, the extension is held in that plane by stationary thrust means which, during movement, controls extension movement in the other plane.

Abstract: Apparatus is disclosed for the formation of pipe comprising one or more layers of thermoplastic resin. The apparatus comprises a die housing having a bore therethrough with a mandrel longitudinally supported within the bore by radial members extending from the inside surface of the bore to provide an annular extrusion passageway defined by the inside surface of the housing and the outer surface of the mandrel. The housing includes therein a plurality of electrically resistive heating elements longitudinally positioned parallel to the extrusion passageway to selectively heat the thermoplastic material flowing therethrough in proximity to the heated section thereby increasing the laydown of thermoplastic material. Also included in the housing is plurality of radially adjustable elements having electrically resistive heating elements therein to radially reposition a moveable discharge sleeve held therebetween thereby controlling the wall thickness of the thermoplastic material passing in proximity thereto.

Abstract: An extrusion head for producing flat profiles such as tread strips for automotive vehicles from three or more different rubber or plastics materials is disclosed. The head comprises a fixed central portion and upper and lower portions pivotally connected thereto, and is fed with the different mixtures by a plurality of screw or worm extrusion devices. Between the upper and central portion and the central and lower portions of the head, insert members are located. In the upper and/or lower surface of each insert member, flow channels for the mixtures are defined, the flow channels each being bounded upwardly or downwardly as appropriate, by a plane surface of one of the portions of the head. The insert members are axially divided and are made in one piece. The flow channels each have a longitudinal axis of symmetry and such axes lie in a common vertical plane.

Abstract: In order to homogenize and to obtain a uniform temperature distribution in a plastics substance, which is to be extruded between an inner and an outer component, in a nozzle, the substance is made to pass a bearing structure comprising a number of rolling bearings, where the balls serve as kneading bodies. The inner and the outer components of the orifice rotate in opposite directions, which will orientate the molecular chains in the surface zones of the extruded products at an angle to the direction of extrusion. In this manner the structure of the product is enhanced, while simultaneously the kneading operation reduces the risk of impurities in the plastics compound causing weak spots in the product.

Abstract: An extrusion die apparatus for producing at least one plastic closure strip having profile and base portions, includes a die body having a die face, a profile channel defined in the die body and communicating with a profile die opening in the die face for extruding a profile portion, and a base channel defined in the die body and communicating with a base die opening in the face for extruding a base portion. The channels are adjacent to each other near the die openings and separated by a portion of the die body which terminates short of the face so that the extruded profile and base portions join together before exiting the die body.

Abstract: The weather strip is intended to be applied to the edge of an aperture or closure element of the body of a motor vehicle and comprises an anchoring section of elastomeric material with a channel section, and a tubular sealing section also of elastomeric material coextruded with the anchoring section. In the portions of the weather strip intended to be applied to corner portions of the edge of the aperture or closure element, or to portions of the edge close to which there are obstacles, the tubular sealing section is curved relative to the anchoring section and is connected to the anchoring section along a curved line.The invention also relates to an extrusion head for extruding a weather strip of the said type.

Abstract: Novel rotary processors which involve a devolatilizing stage including a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage of the devolatilizing stage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material transfer grooves formed in the closure surface.The rotary processors of this invention include a novel vacuum system to evacuate the devolatilizing stage.

Abstract: In the manufacture of film containing integral fasteners and the like, the film commonly exits through an elongated slot die while profiles for the fasteners exit through a smaller configured slot located laterally along the film die slot. The fastener profiles normally carry a thickened base so that the profiles will stand without undue tipping for better interengagement with one another. It has been found that it is advantageous if the base of the profile can be adjusted transversely of the film slot so that the size of the base can be adjusted on-line. The present invention allows the die block to be transversely adjustable by a combination of a U-shaped mounting block, an inverted T-shaped profile plate and an eccentric adjustment pin, assembled in a fashion so that the eccentric pin can be rotated to adjust transversely the gap through which the profile base passes just before joining the film. This device also makes possible measurement of the gap for the profile base indirectly on line.

Abstract: A thermoplastic pipe extrusion die having an adjustment section in a radial portion of the die channel provides excellent control of final pipe wall thickness uniformity.

Abstract: A die for the extrusion of pasta or other paste-like foodstuff material, which is made up in two parts one being inserted into the other, the two parts between them defining a series of apertures the cross-sectional shape of each of which defines the shape of the extruded material. A portion of each aperture is defined by one of the parts so that when the parts are disassembled the parts of the apertures are readily accessible for cleaning and the removal of unextruded material.

Abstract: An apparatus for adjusting die clearance for an extruder producing a sheet in a die having an adjusting device for adjusting the die clearance between an upper die and a lower die, a measuring device for measuring thicknesses of the sheet at a plurality of positions in the direction of width on the sheet, a setting device for setting desirable thicknesses at the positions, an adjusting data producing device for producing data with respect to die displacement to be adjusted from the measured data and the desirable thicknesses, and control device for controlling the adjusting device in order that the die clearance coincides with the desirable thickness. Rough adjustment can be effected by tightening or loosening the bolts while fine adjustment is achieved by heating the bolts with an electrical heater disposed thereabout.

Abstract: A process is disclosed for the formation of pipe comprising one or more layers of thermoplastic resin whereby an annular stream of thermoplastic material is transported through an annular extrusion passageway. The downstream annular portion of the extrusion passageway has a radially movable outer wall. The outer wall is radially moved by heat expansion of a bolt thereagainst to change the thickness of a particular arcuate section of the stream. The thickness of the particular arcuate section of the stream may be further changed through selectively heating by electrical resistive elements an arcuate section of the extrusion passageway to heat the stream of thermoplastic material transported in proximity thereto.

Abstract: A web manufacturing apparatus including a flexible shaping member that engages fluid material of which a web is formed, a support that extends parallel to the shaping member and a plurality of thermal expansion rods that extend between the shaping member and the support so that the shaping member can be flexed to control the web thickness profile by means of heaters on the thermal expansion rod. Each thermal expansion rod is fixed to the shaping member and is secured to the support via a differential screw mechanism that includes a driven screw and an adjusting screw positioned in tandem in a threaded bore through the support and are coupled so that the driven screw can be turned by turning the adjusting screw. The driven and adjusting screws have internally threaded bores and one end of the thermal expansion rod screws into the bore of the driven screw.