Abstract: An encapsulated multiple glazed structure is formed by positioning at least two spaced apart substantially coextensive sheets of glazing material wherein the sheets are maintained in aligned spaced relation by a suitable spacer element adjacent the peripheral portions of the facing surfaces of the glazing sheets. The above assemblage is then typically placed within a mold cavity of a suitable molding apparatus and a charge of an elastomeric gasket forming material is injected therein to form an encapsulating gasket around the peripheral edge portions of the assemblage to produce a multiple glazed structure.

Abstract: A phototool having a first frame assembly hingedly connected to a second frame assembly by way of a hinge assembly wherein each frame assembly comprises a frame member with an insert opening through the frame member defining an edge and a glass member having an edge. The glass member is insertable into the insert opening with the edge on the glass member being spaced a distance from the edge on the frame member defining a connecting space therebetween and an adhesive is disposed in the connecting space for connecting the glass member to the frame member. The glass member is connected to the frame member by establishing a vacuum in the connecting space for pulling the adhesive in the connecting space. The adhesive in connecting space is cured for connecting the glass member to the frame member via the cured adhesive.

Abstract: A masonry structure is made by setting up a prefabricated wire support structure having the shape of the structure to be made, assembling a first row of bricks on the lowermost horizontal section thereof, masking a plurality of brick of that row with an open top removable mortar molding form which is placed around a plurality of bricks and covering the tops of the bricks by filling the form with mortar and leveling it to provide a mortar filling layer between adjacent bricks of the run and a continuous mortar layer above the bricks.

Abstract: In a method of sealing structural bodies or cavity-defining walls which may be subject to cracking, a sealing material is applied to the outside surface of the bodies or walls, the body or the cavity-defining walls are surrounded or enclosed by enclosing walls which are spaced from the body or the cavity-defining walls and a flowable sealing fluid having a high viscosity is introduced into the space thus formed.

Abstract: A method of fabricating a composite structure having at least one skin molecularly bonded to a core. A skin is provided of reinforcing fibrous material and a thermoplastic matrix. The skin is thermoformed to the general exterior shape of the composite strucutre. The skin is placed in a mold, and a core material is injected into the mold against the skin under isostatic conditions. The core material includes a thermoplastic matrix compatible to the thermoplastic matrix of the skin to form a molecular bond therewith.

Abstract: A method for manufacturing an electronic device having therein a lead frame and a vibration-generating element integrally provided on the lead frame. The lead frame and the element are first provided in a metallic mold assembly comprising an upper mold portion and a lower mold portion, the upper and lower mold portions respectively having recess portions so as to form a cavity when the upper and lower mold portions are assembled with each other. A first sealing material is injected into the cavity so that the element is covered by the injected first sealing material, the first sealing material having a shrinkage property and a low adhesion property. After solidification of the injected first sealing material, they are removed from the mold assembly and then immersed in a second sealing material at a vacuum state so that the second sealing material is impregnated between the first sealing material portion and the lead frame.

Abstract: A lightweight, high strength moldable structure is comprised of a core having a plurality of interconnected cavities. Each solid-walled cavity has a hexagonal base so that the core of the structure has upper and lower surfaces. Each solid-walled cavity has a unique tetrahexagonal shape in which a regular tetrahedron is located on top of and integrated with a hexagonal base. The walls of the cavities may be solid or they may be defined by a series of support struts for an even lighter weight structure. The upper and lower surfaces may be covered by skins, making it suitable for boat hulls, vacuum chambers, and aircraft.

Abstract: A method is disclosed for molding thin gel slabs horizontally having deep, large volume sample wells molded integrally and in communication with the thin gel slab. The disclosure includes a method for molding at least two contiguous thin gel slabs horizontally.

Abstract: The invention relates to multiple glazing, a method for obtaining the same and a device for using said method. The glazing contains two sheets of glass separated by a space of dehydrated air and maintained by a cross-braced frame, of which at least the surface in contact with the glass is a butyl and/or polyisobutylene rubber-based mastic and is covered with a peripheral injection, which adheres in a cohesive manner to the mastic of the cross-braced frame.

Abstract: A method of mounting a magnetic head to a case employs a jig having a grooved placing unit for placing the head and a support for the case formed at a predetermined height from the slidably contacting surface of the head. The method includes placing the slidably contacting surface of the head on the bottom of the placing unit of the jig to position the head in the placing unit, placing the case on the support to set its height at a predetermined gap with respect to the mounting surface of the head, and filling a bonding agent in the gap between the mounting surfaces of the case and the head.

Abstract: A method for fastening soft porous polymer tubes into a fastening seat by remolding the tube ends by compression to remove porosity before insertion into the seat or pressure insertion of a hard, strong tube into each porous tube after insertion into the fastening seat to compress it. An adhesive is used to fill the seat to hold the tubes in place.

Abstract: A method for manufacturing a panel, such as an automotive panel, using the resin transfer molding (RTM) process. The method includes the steps of preforming a first mat of glass fibers into a shape approximating one side of the panel and, similarly, preforming a second mat of glass fibers into a shape approximating a second side of the panel. A urethane core is sandwiched in between the preformed mats to thereby form a premolded assembly. This premolded assembly is placed into a mold and a settable resin is injected into the mold to form the panel.

Abstract: An elongate packing is sandwiched between two sheet-like mold members in an encircling manner to define a mold cavity therebetween, then a thermosetting plastic material is poured into the mold cavity, and the thermosetting plastic material is heated and set in the mold cavity. The upper and lower mold members are held against deformation transverse thereof so as not to be deformed by the shrinkage of the thermosetting plastic material when the latter is set, and the packing is allowed to move transversely thereof for following the shrinkage of the thermosetting plastic material when the latter is set. In some embodiments, the packing comprises a packing body adapted to be sandwiched between the mold members for preventing the plastic material from flowing out of the mold cavity with a flange joined to the packing body and adapted to be held against peripheral edges of the mold members.

Abstract: A method and apparatus for manufacturing an otoplastic. An otoplastic is manufactured directly in the ear of a hearing-impaired person in that a deformable envelope is pulled over a die or over a shell or over an overlayed over-shell. This apparatus is then supplied with flowing otoplastic material between the die and the envelope, being supplied therewith in the ear. The envelope expands and assumes the shape of the auditory canal. After hardening or curing of the otoplastic material in the ear of the hearing-impaired person, the envelope and the die are removed and a module of either an in-the-ear or of a behind-the-ear hearing aid is integrated therewith.

Abstract: To provide a snug-fitting bearing for journalling the spindle end of a printing press cylinder, a flanged bearing sleeve is disposed in a bore in the press frame and an anti-friction plastic material which compensates for the bearing play is injected into an external annular groove in the bearing sleeve of considerably less width than the depth of the bore in the press frame. Preferably, the bore is pretreated with a volatile release agent and the plastic material cures in situ to become a narrow bearing ring in the groove. The bearing sleeve may have eccentric annular shoulders on either side of the groove and a thin annular metal bushing may be interposed between the cylinder spindle and the interior of the sleeve bearing.

Abstract: A method of constructing a wall is shown in which vertical columns are erected by stacking a series of precast concrete elements. The elements are spaced-apart by temporary end members to define an upright passage within the column. Concrete is poured within the passage to fill the column interior. After the concrete hardens, the end members are removed to provide oppositely arranged, vertically extending recesses on the column exteriors. The distance between two completed columns is spanned by sliding a precast panel within two of the columns vertical recesses.

Abstract: Metal plates having respective adhesive layers are put one on one with their adhesive layers inside, and pressed and punched by a metal mold assembly. After the upper plate is separated by a predetermined distance from the lower plate, molten synthetic resin is poured into a cavity between the two metal plates by injection molding, thereby forming a composite member of the metal plates and the synthetic resin. A projected portion which is connected to the synthetic resin layer can be formed through a hole made by punching work.

Abstract: A method of manufacturing a cosmetic puff for liquid foundation includes forming a latex film coating on one side of a crimp pattern plate by applying a latex film compound thereon. The latex film coated plates are set in a manufacturing framework. The foamed latex foam compound is injected into the manufacturing framework while adding a coagulant and an activator therein to hereby produce a gelled latex foam covered with latex films on both sides. The latex foam and the latex films are simultaneously vulcanized to thereby bond the latex films onto the latex foam. A manufacturing framework for a cosmetic puff is also disclosed.

Abstract: On a track for electromagnetically levitated vehicles, side guide rails are positioned on and secured to a beam-like support member forming the track by an apparatus made up of a transportation frame extending in the long direction of the support member and by installation truss frames located on and extending transversely of the transportation frame. Side guide rail installation arms are pivotally mounted on the installation truss frames. With the arms in an outward position the guide rails can be placed on and held by the arms. By pivoting the arms inwardly the side guide rails can be located along the outer sides of the support member. By raising the installation truss frame, the guide rails can be located relative to stators mounted on the underside of the support member. In addition, the final position of the guide rails can be established by moving the installation truss frames transversely of the transportation frame and relative to a plate strip on the upper surface of the support members.

Abstract: For continuous production of block members consisting of outer block elements (2) having an intermediate layer (4) of a binding material, especially lightweight concrete building blocks with a heat insulating intermediate layer of foamed polyurethane, a conveyor is used which has a chain (8) of L-shaped plate members (10) consisting of a carrier plate (14) and another plate portion (16) projecting outwards therefrom. The block elements are placed in spaced pairs on the carrier plate, and the intermediate space is filled with foam material at a dosing station (28). Because of the L-shape of the plate members (10) the block elements (2) may easily be supplied onto the chain as this passes a sprocket wheel (18), and the block elements may be fed to the conveyor during continuous movement of the chain.

Abstract: For the production of articles comprising at least one layer of leather or simulated leather material and one layer of a synthetic resin connected to the first-mentioned layer in a shape-mating fashion, a mold cavity is filled with at least one layer of leather or a simulated leather material which later is in contact with at least one of the mold walls, and thereafter a synthetic resin, in the fluid condition or in a condition wherein it is rendered fluid, is introduced into the mold cavity. Finally, the synthetic resin is allowed to penetrate at least partially into the layer of leather or simulated leather material for the purpose of attaining an at least shape-mating bond therewith, and the peripheral edges of the layer of leather or simulated leather material are allowed to be covered by the synthetic resin.

Abstract: A pour mold includes two parts one of which forms a mold cavity and the other of which forms the lid for the mold cavity; the lid includes a retractable pilot pin and vacuum cups for positioning a mold insert within the mold cavity automatically upon lid closure. The pilot pin loosely pilots the insert in the mold as it closes and as the vacuum cups pull the insert toward the lid during such closure. The vacuum cups hold the insert against the lid continuously during foam injection, foam reaction and cure and as the lid is separated from the mold cavity part so as to automatically remove the finished part from the mold when the lid is separated therefrom.

Abstract: A window assembly includes a transparent glass sheet and gaskets formed by curing a polymeric gasket material in situ on the glass sheet to encapsulate a marginal peripheral edge portion thereof. A glass sheet to be utilized in a vehicle door has a front edge, rear edge and a lower edge to each of which is adhered such a gasket. In addition, a bracket means for attachment to a scissor linkage for raising and lowering the window can be secured to the lower edge of the window. The gaskets are formed in a mold with the transparent sheet and bracket means, typically by a reaction injection molding process. Each of the front and rear gaskets may have a flange portion thereon for insertion in an opening in a gasket attached to a frame of the window opening in the vehicle door.

Abstract: Heat and/or transferring apparatus which comprises at least one group of tubes from synthetic thermoplastic material, in which each tube end is surrounded by a sleeve from synthetic thermoplastic material having no porosity or a prosity of an more than 20% of the wall volume. All tube ends with sleeves of one group are surrounded by a second sleeve, whereby the sleeves of the tube ends have substantially the same length as the second sleeve. On the end face the tube ends are each fused with the sleeve end surrounding the same, adjacent sleeve ends are fused with one another, and external sleeve ends are fused with the second sleeve.

Abstract: A method of producing a layer of plastics material between two glass panes and an apparatus for performing said method, wherein the plastics material is filled in liquid form between the two glass panes which are in an inclined or vertical position and maintained parallel and sealed at their outer edges, are characterized in that the two glass panes are pressed against each other at their outer surfaces by one or a plurality of rotatable devices to achieve pressure guided in parallel and extending preferably over the total width of the glass panes, which pressure devices are movable along the total length of the glass panes, and that the pressure devices are moved at the curing rate of the plastics material from one end of the glass panes to the other end of the glass panes relative thereto.

Abstract: Uncured elastomeric sheet material (42) is built up on the outer surface of a production article (36) constructed from composite materials. A vacuum bag system (20, 24, 26, 30, 32) is used for holding the uncured elastomer member (60) against the composite article (36) while the elastomer member (60) is being cured under heat and pressure. Such curing causes the elastomer member (60) to shrink. The elastomer member (60) is then resized by cutting it into sections (66). The sections (66) are placed back on the composite article (36) and each is positioned on such article (36) at a location best conforming to it in shape. This leaves gaps (68) between the sections (66). Additional uncured elastomer (70) is applied to fill the gaps (68) and bridge across the gaps (68), to in that manner splice the sections (66) together. A vacuum bag (20, 24, 26, 30, 32) is again applied and the bag assembly (20, 24, 26, 30, 32 ) is again cured under heat and pressure, to cure the additional elastomer material (70).

Abstract: Novel composite products formed by bonding a flowable elastomer, such as silicone rubber, to a transparent or translucent silicone rubber preform are described. These products have utility in the field of electromechanical devices such as an illuminated switch or key or as a transparent rubber window permitting view of an underlying display device. The bond between the preformed elastomer and the flowable elastomeric material is improved by post-curing the preform for about 4 hours at about 200.degree. C. prior to contact of the flowable material with the preform. Methods of fabrication of the novel composites are also disclosed.

Abstract: A method of making a mold used in a pressure slip casting process, including the steps of: preparing at least two porous bodies each defining a filter layer having a plurality of channels formed therein for allowing water and air to flow therethrough; placing a reinforcing iron frame and one of the porous bodies on a bottom board with a parting agent applied to its surface; applying a sealing resin to the surface of the other porous body opposite to a molding surface thereof and to a portion of the surface of the bottom board between the box and the porous body; filling up the space between one of the porous bodies and the reinforcing iron frame with a filler; and preparing a second part of the pressure mold.

Abstract: A fastener element is ejection molded from an engineering resin of a type that will bond to potting resin used for securing the fastener element within a cavity formed within a panel of composite material. The fastener element includes flow control disks spaced apart along a stem portion between end portions. Flats are formed on opposite sides of the flow control disks, below fill and vent openings. Resin introduced into the fill hole travels down to the bottom of the cavity and around the fastener element and fills the cavity from the bottom up, so that the presence of resin at the vent opening will indicate that the cavity has been filled with resin and does not include an airspace or void.

Abstract: A composite plastic product is formed by a process which includes formation of a preform of high strength plastic having openings formed therethrough which are covered by a film barrier that is formed during molding of the preform; and wherein the preform is configured to be placed as a unit in a foam station at which material is foamed onto the insert without escape to its backside.

Abstract: In this process for the production of multilayer glass plates with a plurality of glass panes spaced from one another in a frame and with hardenable synthetic material and shaped bodies in the intermediate space between the panes, there is applied to a horizontally positioned first pane (1) the synthetic material (2) before it hardens from a viscous state in selected places and in uneven thickness; the shaped bodies (4) are then brought onto or between the places containing the synthetic material, whereupon a second pane (3) is laid at a spaced interval over the first pane (1) and the set consisting of the two panes is surrounded with a frame (7). In order to bond the two panes of glass together with the synthetic material, the two panes are laid one upon another, turned 180.degree. and maintained in this position while the viscous synthetic material flows downwardly forming threads or drops which join the two panes and bonds them together when the synthetic material is hardened.

Abstract: A method of manufacturing a composite member composed of metal plates and synthetic resin, and more particularly to a method of manufacturing such a member in which bending and drawing can be carried out on the member simultaneously.

Abstract: A method of molding a hollow, fiber reinforced glass matrix composite article. Reinforcing fibers are placed in a mold cavity. A billet of high temperature stable glass matrix material is heated above its flow point. The thus heated matrix materials is flowed into the mold cavity from a point inside of the article being formed and at the relative midpoint along its vertical axis. Improved article tolerance control and minimized article preform fiber disturbance is achieved.

Abstract: A method for the continuous production of foam materials, wherein the foaming and/or foamed synthetic starting material is passed through the pressure zone (4) of a continuously operating press (1), and in which method at least a part of the heat required for foaming is produced in the synthetic starting material itself as dielectric heat of an electromagnetic high-frequency condenser field, wherein production of this heat in the starting material takes place at least to its greatest part within a high-frequency condenser field which is arranged in the direction of passage (8) of the material through the press (1) in front of the pressure zone (4), and that in order to supply additional heat into the foaming and/or foamed starting material or in order to prevent or delay its surface cooling, at least one of the electrodes (10, 11) between which prevails the high-frequency field and/or at least one of the pressure surfaces of the press may be heated.

Abstract: A method of producing a smooth surface on a premolded glass fiber reinforced plastic panel where protruding fibers would otherwise produce a rough surface. The method is practiced by coating the surface of a premolded glass fiber reinforced plastic panel maintained at or near the molding temperature with a polyurethane composition, and applying molding pressure on the coated surface to cause the coating resin to flow and fill the valleys between the protruding fibers. The molding pressure is released while the coating resin is still in its fluid state. A finished, smooth panel is made by this process which can be readily painted and used as an automotive exterior body panel. Optionally, a layer of a predecorated sheet material can first be placed in the upper mold cavity of a mold, then compressed against a premolded panel positioned in the lower mold cavity with a layer of coating resin sandwiched in between.

Abstract: A mirror--typically of the spherical or aspherical variety--is replicated on a large scale (in the order of 2'.times.4') to an optical accuracy in the range of less than one arc minute. An optical master is created by heat shrinking and holding an acrylic sheet to a steel substrate of the same shape as desired mirror in the constant presence of a vacuum at the steel-acrylic interface. The acrylic is optically polished to complete the master. The master is then appropriately dammed to the mirror dimension and poured with subsequently cured epoxy so that the epoxy forms the optical surface of the replicated mirror. A backing master--created by substantially the same process as the optical master--allows fabrication of a backing, composed of a series of adhesive layers typically sandwiching a core material such as commercial honeycomb therebetween, to be made with a curvature substantially similar to the curvature of the replicated optical surface.

Abstract: An improved core structure is provided for composite structures and particularly those employing fiberglass reinforced plastic surface layers. In accordance with this invention, a composite article is formed having a central layer comprised of a plurality of elongated hollow rod like members which are supported by a retaining material. The rod members are preferably made from a naturally occurring hollow material such as bamboo stalks. The retaining material is preferably a foam type plastic such as urethane, PVC, or syntactic foam. The core structure may be fabricated by loading a plurality of bamboo stalks into an elongated trough form, and then filling the trough with retaining material. Following curing, the core body is removed from the form and is sliced into plate shaped individual core pieces. The core structures are thereafter skinned with a plastic outer layer such as fiber reinforced plastic and used to develop webs, bulkheads, reinforcing members and various other features in composite structures.

Abstract: In the case of a method and an apparatus for producing parts with high quality surfaces using a mold and curing resin, such as epoxy resin, the first step is to place a workpiece blank so that there is minimum gap between it and the mold. Then resin is introduced into the gap in a non-separating flow utilizing capillary forces in the gap. The epoxy resin then cures and the workpiece coated with such epoxy resin is separated from the mold.

Abstract: A process for producing a hollow fiber mass transfer module with a number of hollow fibers sealed into a housing is improved according to the invention with regard to the development of a desirable flow space in the surface area of the hollow fibers by the fact that a spacing material is applied to the outsides of the hollow fibers before their insertion into the housing (2). The thickness of the material is chosen to conform to the desired separation of the hollow fibers. The hollow fibers are arranged substantially parallel and inserted as a bundle into the housing and are fixed with the grout. The spacing material can have a layered or particulate and granular form. A hollow fiber mass transfer module produced by the process pursuant to the invention has hollow fibers suitably arranged at uniform mutual spacings.

Abstract: The invention relates to a method for producing insulations of foamed plastic material, in cabinets and doors of refrigerators, freezers and the like.According to the invention, a metered quantity of a foamable mixture is fed into the gaps between the inner and outer walls of a cabinet or door, placed in a foaming jig; the foaming process is controlled by sensing characteristic parameters, for example, the temperature of the jig, cabinet or door, or the pressure of the foaming plastic material, comparing them with reference parameters or data stored in a data processing unit. A control signal is generated to open the foaming jig and to unmold or remove the cabinet or door when at least one of the processing parameters has reached a pre-established value. The metered quantity of mixture fed in each subsequent foaming operation is corrected each time according to the changes in the peak pressure of the foam with respect to the previous foaming operation.

Abstract: A one-piece fishing rod handle is provided in which an integral handle portion is molded together with preformed rod handle components such as a reel seat is disclosed for use in through-rod-type construction wherein the rod blank extends axially through the entire length of the handle and foregrip. The individual preformed rod handle components are assembled onto either a mold core pin or fishing rod blank and properly registered in a mold cavity having the configuration of the finished rod handle. Molding resins such as polyurethane are then injected into the mold cavity and provide a handle portion which is bonded to the preformed reel seat. By the use of two differently dimensioned molds in conjunction with different density molding resins, dual composition one-piece fishing rod handles can also be molded.

Abstract: A method of producing a laminated or resin bonded glazing unit comprising introducing an exothermically setting liquid resin material between a pair of spaced apart glazing panels and allowing the resin material to set, wherein one of the glazing panels is a leaded, stained or decorative glazing panel.

Abstract: In an apparatus and method for producing packs of blades used for cutting ystal bars into discs, the individual blades are first aligned in the position desired by an assembling jig and then fixed at the end portions thereof by fixing agents, whereby the assembling jig is then removed and the pack of blades is clamped in the holding frame of the reciprocating saw. The apparatus and method makes possible a quick and uncomplicated production of the pack of blades, and eliminates the need for small spacer plates that were hitherto common.

Abstract: An apparatus for making composite plastic product includes a mold insert with locating boss formations preformed from high strength plastic having openings formed therethrough; and wherein the insert is configured to be located on a mold cover which carries a locking device to hold the insert in place and wherein the locking device includes automatically operated knock-out means that engage the boss to separate a molded part from the lid when the locking device is released.

Abstract: A process for making a rigid pipe with the aid of flexible parallel coextensive skins interiorly filled with a catalyst-curable flexible filler, where the flexible skins and filler are laid along any desired surface contour and then the interior space within the inner skin is expanded to form the pipe and catalyst is introduced through one or both of the skins which is catalyst-permeable, to produce a rigidized pipe.

Abstract: Refrigerating cabinets of different sizes and shapes may be manufactured by the use of a single positioning member. Thus, the positioning member has a configuration which is adjustable to adapt to the particular shape of a given inner housing of refrigerating cabinet. When the adjustment is made, the performed housing is fixedly positioned on the thus adjusted positioning member. Previously formed outer walls of the particular cabinet involved then are positioned about the thus positioned housing, with a space being defined between the housing and the outer walls. The positioning member further includes elements which may be employed to partially form a foaming jig. This total unit then is moved to a simplified foaming unit, whereafter the formation of the foaming jig is completed, and insulation material is foamed into the space between the housing and the outer walls.

Abstract: A hot water heater includes a storage tank and an outer decorative shell spaced from the tank. A foam insulation fills a cavity between the tank and the shell and a bottom wall in the form of preassembled fiberglass belt. The belt is wrapped and secured about to the tank by an encircling compressing and centrally located band. The outer ends of the belts flare outwardly to a diameter in excess of the inner diameter of the shell. A flat, flexible plastic sheet has a narrow portion draped over the top of the tank and sides extended down and overlap the opposite sides of the belt. The lower ends of the sheet essentially covers the belt. The flexible plastic sheet has a slight angle between the tank top and the belt. The outer shell which has a diameter somewhat less than that of the flared belt is telescoped downwardly over the tank and sheet folds the apron into a circular configuration, compressing the belt tightly between the storage tank and the shell.

Abstract: A relay housing comprising a cover plate which is inserted in a step-shaped recess of a housing rim. The rim portion of the plate has a reduced thickness so that there is formed a rim channel between the plate and the housing rim. The channel is in communication with fill-in cavities in the cover plate through which the channel is filled with a self-hardening or curable material. The fill-in cavities are formed as flat recesses adjoining the rim channel with wide openings, not connected among each other, that are at least twice as large as the width of the rim channel. The bottom of the channel slopes downwardly from said openings. This arrangement permits a quick sealing by use of only small amounts of sealing compound.

Abstract: A high tensile strength and high abrasion resistant removable hose covering and method of construction is described for fabricating a reusable, removable hose covering adapted to surround an inner hose by which high tensile strength in the longitudinal direction may be imparted to the combination of the inner hose and removable hose covering and in addition, extreme high resistance to environmental abrasion is obtained. The inner hose is constructed by conventional methods.

Abstract: The present invention relates to a method of forming the primary core of a concrete pipe. A steel cylinder is disposed vertically on the base of the pipe forming machine. A conventional rotary packerhead having a diameter less than the inner diameter of the steel cylinder is lowered concentrically to the bottom thereof. Concrete is then introduced within the steel cylinder through the upper end thereof. The packerhead is rotated to force the concrete into the annular gap between the packerhead and the steel cylinder. As the primary core is formed, the packerhead is raised and rotated while concrete is introduced within the steel cylinder, thereby forming a primary core consisting of a steel cylinder having an inner lining of concrete. In an alternative embodiment, the steel cylinder is completely embedded within the concrete.