Abstract: In a process for connecting material segments made of an elastomere or of a thermoplastic material the sections to be joined (3,4) are placed between two pressure beams (1,2) in the area of the seam (5) to be created. The pressure beams are not mechanically connected to one another. The forces necessary to hold and to attach the material segments (3,4) are generated by the evacuation of suction chambers formed between the cavities (9) in the contact surfaces (6a,6b) of the pressure beams (1,2) and the segments to be joined (3,4).

Abstract: An apparatus for inserting an internal lid (6, 7) in a tubular formed container (1) and for sealed connections of the lid to the inner of the container tube by constant heat welding, high frequency welding or ultrasonic welding and comprising a carrier (8) for holding the container tube (1) while introducing and weld connection the lid (6, 7), a support provided above the carrier (8) for positioning a plane punched out lid blank having a larger outer periphery than the inner periphery of the container tube, a piston means (16) pressing the lid blank into the container tube while folding a narrow edge rim (7) upwards from the lid plane (6) and in which the piston means comprises a lower piston part (18) and an upper piston part (20) which are axially movable in relation to each other and an expandable means (19) between said two piston parts (18, 20) which expandable means is pressed radially outwards when the two piston parts (18, 20) are compressed.

Abstract: Methods and apparatus for forming seal in a packaging material through containing a plastic combestible such as process cheese, utilizing sealing element having a plurality of small channels in the surface thereof having a directional component laterally of the longitudinal axis of the sealing element.

Abstract: This invention is an improved heatseal die that forms superior airtight seals. The die has opposed die faces, with one die face having longitudinal lands and the other die face having grooves for receiving the lands. The lands are truncated and the depth of the grooves is greater than the height of the lands. As a result, the force applied by the lands and grooves is applied entirely as a shearing force, which forms the superior heatseals.

Abstract: A welding tip configuration for ultrasonically welding thermoplastic material includes a plate with conical projections extending from a planar surface thereof and reservoirs recessed below the planar surface and spaced from the projections. The reservoirs facilitate the displacement of molten material away from the conical projections.

Abstract: To cover the concave face of a lens preform with a protective sheet of transparent plastic by an elastic pressing element, the invention proposes inserting an elastic membrane between the pressing element and the protective sheet. Before or during pressing, the membrane is lowered over the preform which has been provided with the protective sheet. As a result of its presence, the entire peripheral area of the protective sheet can be applied homogeneously against the edge of the preform.

Abstract: A wood product including a quantity of adhesive coated coarse wood particles disposed between a pair of cellulosic fiber webs is embossed in a heated press by means of a caul plate carrying a plurality of inserts adapted to impress a desired relief design comprising a plurality of adjacent but independent panel configurations in the wood product. The inserts are attached to the caul plate and extend to selected levels for compressing the wood product to different embossing levels characterizing each panel configuration. The individual caul inserts are machined to shape and are separately photo-etched to receive a desired decorative pattern thereon, after which the inserts are assembled onto the caul plate for impressing the wood product. The panel configurations produced in the wood product are suitably separated into substantially rigid, embossed furniture elements or parts having a carved or inlaid appearance.

Abstract: An automatic form-and-fill packaging machine especially adapted for the ultrasonic sealing of food products in flexible bags from ultrasonically sealable flexible packaging material, and a method to utilize said machine. A packaging machine is provided with a first ultrasonic back seal forming unit for producing a continuous longitudinal back seal on the bag, and a second ultrasonic sealing unit provided in a pair of jaw members which are adapted to form the end seals of the bag perpendicular to the direction of travel of the packaging material. The second ultrasonic sealing unit is provided with a horn and an anvil in opposing jaw members, such that when the jaws are shut, the flexible packaging material is tensioned against sealing land areas to provide the end seals.

Abstract: An apparatus for forming grooves in the peripheral surface of a filter rod includes an endless conveyor device having a generally horizontal top conveyor flight which intermittently moves the filter rods through the apparatus. The endless conveyor device has a plurality of filter rod receiving pockets at spaced apart intervals along its length. The pockets in the horizontal top conveyor flight hold cigarette filters to be grooved at predetermined spaced apart intervals as the endless conveyor device moves the filter rods through the apparatus. A plurality of pairs of articulated grooving fingers are located generally below the horizontal top conveyor flight at predetermined spaced intervals along the top flight, and a plurality of pairs of articulated grooving fingers are located generally above the horizontal top flight at predetermined spaced intervals along the top flight. A groove forming blade is attached to the tip of each finger of each pair of fingers.

Abstract: Apparatus for heat transfer labelling of articles using a resilient pad maintained at elevated temperatures. Decorative laminates affixed to a support member such as a web are fed to a heated platen. A resilient pad consisting of a silicone elastomer is pressed against the laminate at the heated platen, whereby the laminate adheres to the pad when it retracts from the platen. The heated pad is then pressed against an article to be labelled, to which the transfer substrate adheres in preference to the pad surface. The resilient pad is typically heated to a temperature above ambient temperature but lower than that of the heated platen. The pad is heated by repetitive contact with the platen, and additionally by an independent heater. The pad may include one or more interior heating elements, or an exterior radiant heater located adjacent the pad during periods between label transfers. This apparatus is well suited to the labelling of articles of a wide variety of sizes, shapes, and materials.

Abstract: What are disclosed are method and apparatus improvements in a heliostat for reflecting solar energy onto a collector, the heliostat having a main support structure with pivoting and tilting motors and controls and mirror modules for reflecting the solar energy. The improvement is characterized by one of a combination, or curved, or lightweight mirror module in which the curved mirror focuses the energy more precisely, attenuates differential expansion due to temperature change, yet is simple and economical to build and is light enough in weight to enable building larger modules for the heliostats, as well as building larger heliostats. The specific improvement is characterized by a curved mirror formed over a plurality of templates with longitudinal support beams holding it into the predetermined curvature with transversely extending structural beams and attachment bolt for attaching it to the heliostat. Also disclosed are specific preferred methods steps and structural components.

Abstract: An integral wood veneer strip having first, second, and third mutually generally perpendicular portions is produced simply and easily. A number of similarly shaped thin strips of wood, with adhesive between them, are placed together to form a linear laminate. Before curing of the adhesive, the laminate is placed in contact with a particularly contoured female die surface, with a flexible band over the laminate. A male die surface provides a pressing force at a central portion of the band to press the laminate into close conformance with the female die surface, and the ends of the band are attached up to rollers. The rollers are rotated to tighten the ends of the band, also bringing the ends of the laminate into tight contact with the female die surface. The adhesive is cured while the laminate is in the bent position (the curing may be facilitated by using microwaves), and then the laminate is released after curing, and may be utilized as decorative molding for furniture.

Abstract: In an elastic band applicator for diapers using hot melt glue, a longitudinally tensioned moving plastic backing sheet is run over a roll that is parallel to and spaced from a stationary cylinder. A shoe deflects the central region of the sheet away from its plane at a location between the roll and cylinder. This results in the margins of the sheet beyond opposite ends of the shoe becoming loose flaps. Glue stripes are applied by means of nozzles to the sheet near its edges before the sheet encounters the shoe which has passageways for the glue stripes. Elastic bands are fed into the passageways onto the glue stripes. After passing the shoe, the margins encounter plows which turn or fold the margins over the glue stripes and bands and press the sheet against a cylinder to smooth the margin. Means are provided for retracting the sheet away from the hot nozzles if the sheet stops moving.

Abstract: Elongated hollow members or tubes frictionally engage the interior wall of a hollow corrugating roll or a hollow pressure roll of a single facer so as to minimize the elastic vibration thereof and thereby to minimize the noise developed and transmitted during the operation of the single facer. A plurality of such tubes of a given diameter are arranged circumferentially about the interior wall of the shell of a roll of a single facer in such manner that each of the tubes frictionally engages the interior wall and so that each of the tubes also engages the adjacent tubes on either side thereof, thereby providing an assembled structure in which the plurality of tubes resist the elastic deformation of the roll and the resultant elastic vibratiion and thereby reduce the noise level.

Abstract: What are disclosed are method and apparatus improvements in a heliostat for reflecting solar energy onto a collector, the heliostat having a main support structure with pivoting and tilting motors and controls and mirror modules for reflecting the solar energy. The improvement is characterized by one of a combination, or curved, or lightweight mirror module in which the curved mirror focuses the energy more precisely, attenuates differential expansion due to temperature change, yet is simple and economical to build and is light enough in weight to enable building larger modules for the heliostats, as well as building larger heliostats. The specific improvement is characterized by a curved mirror formed over a plurality of templates with longitudinal support beams holding it into the predetermined curvature with transversely extending structural beams and attachment bolt for attaching it to the heliostat. Also disclosed are specific preferred methods steps and structural components.

Abstract: What are disclosed are method and apparatus improvements in a heliostat for reflecting solar energy onto a collector, the heliostat having a main support structure with pivoting and tilting motors and controls and mirror modules for reflecting the solar energy. The improvement is characterized by one of a combination, or curved, or lightweight mirror module in which the curved mirror focuses the energy more precisely, attenuates differential expansion due to temperature change, yet is simple and economical to build and is light enough in weight to enable building larger modules for the heliostats, as well as building larger heliostats. The specific improvement is characterized by a curved mirror formed over a plurality of templates with longitudinal support beams holding it into the predetermined curvature with transversely extending structural beams and attachment bolt for attaching it to the heliostat. Also disclosed are specific preferred methods steps and structural components.

Abstract: A machine for crimping tire bead rings in which an inner die member has grooves for holding the bead rings in the area of the bead splices and an upper die member engages the outer surface of the bead rings in that area. The die members are compressed with sufficient force for a sufficient period of time so that the strands of the bead rings are held together by the insulating material around the strands in the area of the bead splices. The side portions of the grooves control the spreading of the bead rings and may be flared to compress and then release the bead rings. The grooves of the inner die member may have movable inserts for ejecting the bead rings. The upper die member may also include grooves in mating engagement with the grooves of the inner die member for enclosing the outer portions of the bead rings at the splice area and provide for release of the bead rings after crimping.

Abstract: Apparatus for feeding a laminate pack into a press and for discharging the finished product such as a laminated, finished board. A plurality of lifters and holders arranged on support arms are provided along the longitudinal edge of the finished board to remove it from the press. These same support arms carry conveyors to transport the laminate pack into the press at the same time or before the finished board is discharged. Fast operating cycles are obtained by reducing the feeding and discharge operating times.

Abstract: A fiberglass reinforced plastics steering wheel is disclosed and a mold and method for making same. The wheel is made by disposing binder and the fiberglass in an annular cavity and in ramp-like radial cavities of a mold and are pressed into shape by a wedge-shaped member.

Abstract: A steel caul for forming wood panels is sandblasted to roughen the contact face thereof. The process of roughening the face results in a multiplicity of minute indentations in the surface of the face which function to capture and retain therein carbonized materials which are produced when the caul is employed to press panel products, thereby extending the period which the caul can be used without the need for cleaning carbon deposits from the same.

Abstract: An apparatus for applying a printing or cutting force to an elongated strip of tape comprising a base, a printing station, a pair of side walls extending upwardly from the base and each including a tape receiving opening, a printing or cutting member and a force exerting element. The force exerting element includes a curved force exerting surface with the axis of its center of curvature being parallel to the path of travel of tape through the apparatus and a structure for supporting and guiding the force exerting element in movement between a first and second position.

Abstract: Apparatus and method for forming sealed joints, including a pouring lip sanitarily protected therein, by welding layers of thermoplastic coated paperboard together. Paperboard layers are pressed together by jaws, with relieved areas where excessive pressure would render pouring lip less satisfactory, while or after heat is applied to said paperboard layers. The apparatus and method is particularly useful for forming sealed joints for paperboard cartons, such as milk cartons.

Abstract: A laminated thermosetting decorative sheet has on its surface glossy protruding parts and matted recessed parts, and the recessed parts are preferably colored. This laminated thermosetting decorative sheet is manufactured using a press plate with an enamel layer having protruding parts whose enamel surfaces are matted.

Abstract: A device for forming the body and bottom of a container of the kind wherein there is an axial seam formed by adhesively-joined overlapping portions of the side and a bottom formed by an upwardly-folded lower end portion of the bottom adhesively enfolded within a downwardly-folded portion of the lower end of the side, said device comprising an ultrasonic side seaming device for welding the side seam, said side seaming device embodying an elongate, ultrasonic horn and means therein defining a planar contact surface containing a stepped-down recess commencing several millimeters from one end for engagement with the side seam and a bottom seaming device comprising an outer mold containing a mold cavity for receiving the bottom, said outer mold containing a centrally-located circular hole, a shaft, a knurling tool supported by the shaft within the mold cavity for rotation about its axis and movement circumferentially within the hole and means circumferentially of the knurling tool defining a circumferential wall a

Abstract: A laminated thermosetting decorative sheet has a three-dimensional pattern on its surface which consists of protruding parts and recessed parts forming smooth curves. This decorative laminate is manufactured by using a press plate having an enamel layer on the surface of a metal substrate.

Abstract: An apparatus for producing girders, as for example I girders, from lengths of wood forming the flanges and the web of the girder has a carriage running on rails through a first station in which lengths of wood are placed thereon for forming the girder, a pressing station in which the so put-together girder is first acted upon by an upright force normal to its web and parallel to its flanges, and then by a greater force acting horizontally on the girder so that the parts of the girder are kept lined up and in righted, straight condition, and through a HF station in which the girder is moved past HF electrodes for acting on the glue in the joins of the girder.

Abstract: Disclosed is a method and apparatus to facilitate the method of discontinuously laminating at least two thermoplastic layers together. The layers are heated and pressed together over all but a selected window portion of the layers to facilitate lamination between the layers at all points except the selected window portions. Relief grid images can be embossed in the selected window portion or holograms or other difficult to forge inserts can be provided in these window areas prior to lamination. During lamination, the reduced or absence of heating in these window portions permits lamination of the card without destruction of the selected window portion insert.

Abstract: An automatic unit for the programmable tucking in of part of a piece of material and the automatic fixing of this tuck by a heat-sealed reinforcement comprises two machines arranged at an angle of 150.degree. relative to one another and symmetrical with respect to the median axis separating them.

Abstract: A laminating machine is disclosed for use in laminating upper and lower heat activatible films on an object. Preferably a packet is employed having upper and lower film leaves within which the object is placed. The packet is received in the laminating machine which has a heating and compression zone formed of upper and lower heater assemblies followed by drive rollers. The heater assemblies are movable towards one another and both heat and compress the film packet as it moves through the machine drawn by the drive rollers. At least one of the heater assemblies has a tapering member which causes increased pressure along central portions of the packet relative to edge portions so as to create a wave in front of the heating and compression zone which spreads the material out evenly and prevents wrinkling or creasing during laminating.

Abstract: A method of and an apparatus for producing a seat cushion member by laminating a sheet of decorative surface material, a sheet of usual polyurethane foam material and a reinforcing web of fabric material in the above order, and subjecting the laminate to heating by a conventional heating unit and, at the same time, to high-frequency dielectric heating by a high-frequency welder to locally fuse required portions of the sheet of usual polyurethane foam material thereby welding the three layers into an integral structure.

Abstract: A method of printing wherein a material to be printed is applied onto a pattern which is preprinted on an extendible film which is extended on an accumulated granule layer composed of a number of spherical granules so that the preprinted pattern at its whole surface is adhered to the surface of the material to be printed by forcing the material to be printed into the accumulated granule layer.

Abstract: Composite moulded rubber or plastic articles, each comprising two distinct parts separately formed by injection moulding of different materials and subsequently joined together by vulcanising or the like, are produced in a dual purpose apparatus that simultaneously moulds two separate parts and bonds together two previously moulded parts.

Abstract: Apparatus for continuously producing an elongated composite tape transducer having an inner laminate with a conductive dielectric-covered strip and two outer laminates each with a conductive foil comprises two reels containing the outer laminates and one reel containing an inner laminate, a station for electrically charging the dielectric layers on opposite sides of the inner strip, a mold for applying and sealing the outer laminates to opposite sides of the inner laminate to form the composite transducer, and a mechanism for pulling the three laminates through the apparatus. The lead end of the inner strip is electrically grounded. The charging station has two electrodes connected in parallel to a source of high DC voltage and physically positioned to make electrical contact with the dielectric layers, respectively, on opposite sides of the inner strip.

Abstract: A multi-piece, tub shaped paperboard container having a circular opening in the top thereof is provided with a multi-piece, reinforced rim coated with a layer of meltable plastic and is assembled by appying heat to overlapping seams in order to melt the plastic coating and thereby seal the seams. Heat is applied evenly around the entire periphery of the rim by a 2-piece, annularly shaped, heated collar which may be selectively shifted into conforming engagement with the container. The even application of heat around the entire periphery of the rim equalizes the surface tension of the plastic coating during melting thereof to avoid deformation of the rim during the heat sealing process.

Abstract: A method of butt-joining metal tapes coated on one or both sides with a film of thermoplastic polymer material.The film is detached from an end portion of each tape (1A 1B) by immersion in a solvent at its boiling point. The detached film is removed and the ends of the two tapes welded together. A film (17, 18) of high-density polyethylene and ionomer resin is applied to the stripped area and bonded thereto by the application of heat and pressure. Device for implementation of the method.

Abstract: A plastics foam-forming mixture (31), e.g. a polyurethane or polyisocyanurate foam mix, deposited from one or more static dispensers (19) is metered through two spaced opposed members (14 and 18) forming between them a metering gap. At least one of the members having a plurality of faces of different profile and being rotatable to present to the other member a selected face appropriate to the thickness of foam board to be produced. Reduces "crowning" of foam boards while permitting foam boards of different thicknesses to be made without having to replace metering bars.

Abstract: A method and apparatus for removing a liner from a formed metal closure by at least partially everting the closure with an advancing punch adapted to temporarily couple the everted closure. By everting the closure, the liner becomes accessible to be retained within the closure support and is separated from the closure when the punch is retracted. A stripper is provided adjacent the punch to separate the everted metal portion of the closure from the punch.

Abstract: In a welding apparatus of the type including a pair of opposing press plates relatively movable toward and away each other and each supporting a molded article to be welded together, and a heating plate movable into and out of a space between separated molded articles for fusing confronting surfaces of the molded articles whereby the molded articles are welded together by applying pressure thereto by the press plates, there are provided mold frames on the press plates. The mold frames define an opening having substantially the same contour as the molded articles to be welded together but having a slightly smaller size than the molded article. The inner surface of the opening is provided with an outwardly inclined surface.

Abstract: Two rectangular pieces of plastic material corresponding to the top and bottom layers of the bag to be formed are placed end to end and looped to form a tube. The overlapped ends are partially welded together to leave long access slits to the tube. The incompletely formed tube is telescoped over a welding die having the same general configuration of the tube, but axially compressed. The edges of the tube openings are turned inwardly over the generally rectangular rims at opposite ends of the die. The corners of the rims are rounded so that the inwardly turned edges form a one layer continuous flange free of wrinkles. Rectangular end pieces are then lap welded to the flange. The incompletely formed waterbed mattress is removed from the die. Individual baffle structures are welded to the top and bottom layers of the bag by secondary operations in which a jig mounting a row of baffle structures projects through the tube slits to position the baffle structures during a welding operation.

Abstract: Apparatus for applying outside heads in the form of paperboard disks to the ends of wrapped paper rolls has platens provided with means, i.e., recesses, for accommodating protruding roll core ends in a manner to avoid interference of such protruding core ends with efficient, uniform application of the heads to the ends of the wrapped paper rolls. Means cooperate with the core end accommodating means for holding the heads on the platens until the heads have been applied to the roll ends. Such holding means desirably comprise an array of radiating channels dead ended adjacent to the core end accommodating means recess on each platen and communicating through ports adjacent the dead ends with a suction device, i.e., blower fan.

Abstract: Method of making attenuation sandwich panels having a cellular core positioned between and bonded to an imperforate facing sheet on one surface thereof and a perforate sheet with an outer layer of porous fabric material adhered to the other surface. The combined perforate facing sheet and porous fibrous material have a predetermined open surface area prior to its adherence to the cellular core. A coating of adhesive is applied to either the facing sheets or to the faying surface of the cellular core. The sheets are then properly positioned with respect to the cellular core. The porous fabric surface of the combined perforate sheet and porous fibrous material is positioned against a perforated plate. The opposite surface of the perforated plate is positioned against a bonding tool that has a plurality of longitudinal grooves on its perforated plate adjacent surface.

Abstract: Method of making attenuation sandwich panels having a cellular core positioned between and bonded to an imperforate facing sheet on one surface thereof and a perforate sheet with an outer layer of porous fabric material adhered to the other surface. The combined perforate facing sheet and porous fibrous material have a predetermined open surface area prior to its adherence to the cellular core. A coating of adhesive is applied to either the facing sheets or to the facing surface of the cellular core. The sheets are then properly positioned with respect to the cellular core. The porous fabric surface of the combined perforate sheet and porous fibrous material is positioned against a perforated plate. The opposite surface of the perforated plate is positioned against a bonding tool that has a plurality of longitudinal grooves on its perforated plate adjacent surface.

Abstract: The improved impulse heat generation and sealer apparatus of the present invention comprises preferably a metallic heat sink block bearing a shallow groove on the face surface thereof. The shallow groove is lined with a thin layer of an electrical insulator/heat conductor and the groove is filled with a preferably metallic electrically conductive material to form a smooth and preferably co-planar surface with the face surface of the metallic block. This smooth surface is coated with a thin layer of a release coating. A resilient mating surface is provided in preferred embodiments for reciprocating motion, whereby an electrical impulse rapidly generates heat in the groove filler material to bond together sheets of a polymeric material disposed between the mating surfaces, and the heat is rapidly dissipated to prevent damage to the sealed sheets. In other embodiments, the heat sink structure may be utilized in heat radiators or any other fast cycling heat exchanger.

Abstract: A tube of thermoplastic netting is drawn through a work station in a radially collapsed, condensed condition. At the work station, the netting is angularly twisted to rope-like form, to increase its bulk density and, in such condition, is drawn between the die and platen of an ultrasonic welding horn. Periodically, the die and platen momentarily bear against a succeeding short length of the twisted, condensed rope-like form making a fused seal nugget integrating all strands of the netting at that site. The resulting product may be a long length of such tubing, having such a seal every so often, or a plurality of bags formed from the intermediate product by making one transverse cut through the netting tube beside each seal nugget.

Abstract: A method and apparatus for closing and sealing the end of a container having a tubular body wherein the container and closure portion includes front, rear and side panels each extending axially from the tubular body in the open position of the end closure. Each of the end closure panels may have a sealing strip defined at its outer end by a scored line with the rear panel including a closure flap-extending from the outer edge of its sealing strip. The end closure panels are folded to a flat closed position by closing jaws with the sealing strips and closure flap projecting axially from the tubular body, after which the sealing strips are sonically welded together. The closure flap and sealing strips are then folded flat, and the closure flap is welded to the outer surface of the front end closure panel.

Abstract: Two parallel guide rails are arranged to put therebetween a stationary die of the hot-press machine and a table for sliding therealong respective movers by which a facing layer is carried from a first position to cover the table to a second position to cover the stationary die. First clamping means is disposed on the movers to clamp longitudinally opposed ends of the facing layer, and second clamping means is connected to the stationary die to clamp laterally opposed ends of the facing layer when the facing layer which has been kept clamped by the first clamping means is brought to the second position by means of the movers.

Abstract: A method of making close tolerance laminates comprises the steps of positioning in an open stack a plurality of B-staged epoxy resin saturated fibrous sheets and providing the top and bottom of each stack with a contour pad, the stack-facing side of which is adapted to provide a horizontal pressure gradient ranging from higher at the center to lower at the edges, and consolidating the stack under heat and pressure. In contrast to conventional processes which produce laminates which are eliptical in shape (thicker in the center), the new process produces laminates having little or no center-to-edge variation.

Abstract: A method and a machine for manufacturing multi-tube filters. The filter is manufactured from a continuous material web which is folded in zigzag, one layer upon the other, the length of the respective layer corresponding to the desired length of the filter tubes. During the folding of each layer, said layer is joined to the layer below by parallel, lengthwise seams, whereby rows of contiguous filter tubes are formed and neighboring rows of filter tubes are joined together. The seams that delimit the respective tubes in a row of filter tubes are positioned in alignment with the corresponding seams in all the other rows of filter tubes and the seams that join together neighboring rows are positioned right between said tube-forming seams. The interconnected layers form, when the filter unit is extended in a direction at right angles to the layers, a filter unit comprising a plurality of tubes that are essentially square in cross-section.

Abstract: A manually operable combination strapping tool for applying plastic strapping around an object includes a strap-tensioning and gripping mechanism for holding the strap in a tensioned loop around the object with the supply portion of the strap overlapping the leading end thereof, and a heat-sealing mechanism which includes a movable pressure block and a heater movable to and from a heating position between the overlapping strap portions. As the heater is moved between the overlapping strap portions, the pressure block is moved to cooperate with an anvil to press together the heating element and strap portions for melting thereof. After retraction of the pressure block and the heater by separate bias means, the pressure block is moved for cooperation with the anvil to clamp therebetween and bond together the melted strap portions and sever the supply portion of the strap.

Abstract: A platen assembly for simultaneously contact heating surface portions of two polyethylene thick-walled pipes that are to be joined together in a heat bonding process is provided with opposed platen surfaces configured to match the respective pipe surface portions to be heated. The platen assembly is adapted to be placed between the pipe surface portions and an electric heating element in the platen assembly heats the platen surfaces to a temperature sufficient to heat melt the pipe surface portions contacted thereby. The platen surfaces adapted to contact the pipe surface portions are formed with ridges and grooves over their full extent to increase the surface thermal contact between the platen surfaces and the pipe portion surfaces. The ridges and grooves on one platen surface are aligned, respectively, with the ridges and grooves on the other surface to form aligned ridges and grooves in the heat melted pipe surface portions.