Abstract: Apparatus is disclosed for fabricating an internally coated pipeline for transporting corrosive and/or erosive materials in which the pipe sections are joined by welding. The pipe sections are first internally pre-coated to the exclusion of a length at each end that is affected by the heat of welding the sections together. After the weld has been made between adjacent pipe sections, an expansible and retractable mold is positioned in the area of the weld joint to define an injection cavity between the pre-coating ends. A coating material is injected into the cavity. The mold can then be retracted and moved to another weld joint where the process is repeated.

Abstract: A window assembly includes a windshield and a gasket formed by curing a polymeric gasket material in situ on the windshield to encapsulate a marginal peripheral edge thereof and form an integral leaf screen and mounting tab. The gasket is formed in a mold with the windshield typically by a reaction injection molding process. The gasket-forming cavities in the mold can be separated by removable plugs and be connected to multiple inlet means for separately filling the cavities. The gasket, leaf screen and mounting tab can be formed of one material, or the leaf screen and tab can be formed of a different material than the gasket.

Abstract: The present invention is directed to an apparatus for the production of back-foamed cushions from cover materials and foam comprising:(i) a mold comprising an upper mold half and a lower mold half, said lower mold half defining a cavity, the inside surface of which is capable of being covered by said cover material,(ii) a mix head associated with said mold, said mix head capable of introducing foam materials and/or reactants into said mold cavity, and(iii) at least one pressing element for pressing said cover material into said mold cavity, said pressing element having a pressing edge which consists of at least one balanced spring.

Abstract: The present invention is directed to an apparatus for the production of back-foamed cushions from cover materials and foam, comprising:(i) a mold comprising an upper mold half and a lower mold half, said lower mold half defining a cavity, the inside surface of which is capable of being covered by said cover material,(ii) a mix head associated with said mold, said mix head capable of introducing foam materials and/or reactants into said mold cavity,(iii) an upper ram provided above the lower mold half, and comprising several segments with contact pressure surfaces, which segments are mounted to be displaceable in guide bores of a supporting frame and wherein springs are associated with said segments, said springs acting on said segments in the direction of said mold cavity, and wherein when said upper ram is in the position of rest, the various contact pressure surfaces are located at different distances from the bottom of said mold cavity, and(iv) wherein said lower mold half is movable towards and away from

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: An apparatus is disclosed for encapsulating a plurality of electronic components, which are bonded to the conductors of a strip, within a mold. The apparatus has an injection unit made up of a plurality of plungers slidable in a carrier and controlled by hydraulic cylinders. The hydraulic cylinders apply pressure to the plungers, which have a heating element for heating the material to be injected. A sensor attached to each plunger senses when the material is sufficiently softened, at which point a driving mechanism drives the entire carrier toward the mold, causing the plungers to inject the material into the mold.

Abstract: A filter comprises a pleated fabric filter bag of generally rectangular configuration within which is removably disposed an internal reinforcing cage of wire or rigid plastics material. The pleated fabric filter bag has an open end and a closed end and at its open end there is moulded integrally with the bag an apertured plastics end cap which has an internal configuration corresponding to the pleated fabric bag. The closed end of the bag is sealed either by the bag material or by an integrally moulded imperforate plastics end cap.The filter can be disposed vertically or horizontally within the casing of a filtering apparatus and if disposed horizontally it can be stacked in vertical array.The rectangular pleated fabric filter permits a substantially greater area of filter fabric within a given size of filtering apparatus, casing or housing than has been possible hitherto.

Abstract: The invention comprises a method and apparatus wherein an insert, preferably made of plastic and preferably allowing a melt-on bonding with the tubes and whose floor has a traversing opening for each tube, is inserted into the first part of the injection mold (top mold or bottom mold) as a positioning element for the tubes in such a manner that the insert is at least partially locked or secured into the first part of the injection mold. A tube is then placed in each opening of the insert. A mandrel is then placed in each tube, whereupon the injection mold is locked in such a manner that, if necessary, the mandrels are locked into the second part of the injection mold (bottom mold or top mold). A molten thermoplastic material is then injected, via a sprue provided in the injection mold, into a cavity formed by the injection mold, the insert and the tube ends.

Abstract: Described is a drive for injection mould parts of a synthetic plastics injection moulding apparatus for injecting a wall part on a paper web, with at least one supply injector fixed on a carrier, a plurality of injector heads rigidly connected thereto and with driven connecting levers.

Abstract: Panels having an integral coat of a cross-linked polymer matrix are formed in the cavity of a closed mold consisting of a lid and a tray; the preformed core of the panel is supported but by the lid and an essentially continuous free space corresponding with the coat to be formed around the core is maintained between the latter and the mold cavity; an essentially prismatic space or chamber is provided at a rim juncture of tray and lid adjacent to, yet outside of, the mold cavity of the closed mold; an elongated slit-shaped opening extending over at least half the length of one side of the mold cavity is formed at an end of the prismatic space; the inlet opening ends in the prismatic space and an essentially laminar flow is achieved throughout the mold cavity when a liquid resin composition that has a viscosity of less than 10 Pascal.

Abstract: A device is described for positioning a reinforcing cage within a cylindrical concrete pipe form. The device comprises a horizontally movable slide which may be moved inwardly into the form for engagement with the cage. A cam is secured to the slide for moving the slide inwardly and outwardly relative to the form. An air cylinder is pivotally connected to the cam for pivotally moving the cam. An adjustable stop is located in the pivotal path of the cam to limit the inward movement of the slide. A plurality of the devices are mounted on the form in a radially spaced and vertically spaced manner.

Abstract: A plunger is used for a multi-plunger type resin mold device which is adapted to be slidably inserted into a pot to permit a resin in the pot into a mold. The plunger includes a forward end member whose forward end edge portion is formed of silicon nitride, silicon carbide or zirconia, the forward end edge portion of said forward end pot member being in contact with the resin in the pot, and a plunger body to which the forward end member is fixed. The forward end member is fixed to the plunger body by threadably inserting an insertion section of the forward end member into a recess formed in the plunger body.

Abstract: Transport anchors to be introduced into moulds for concrete parts are held at disposal in a magazine. An ejection device transversally displaceable with respect to the longitudinal axis of the lowest transport anchor in the magazine brings the transport anchor to a gripping member which grips the head of the transport anchor. By means of a displaceable carriage carrying the gripping member, the transport anchor seized by the gripping member is introduced into the mould by its free end.

Abstract: A flexible link belt is made by injection molding link portions into and through a flexible carrier webbing, whereby the link portions are also bonded to each other through holes in the webbing. The injection mold used for making the links has two mold sections each with a cavity portion corresponding to the respective link portion. The carrier webbing is held in place between the two mold sections. An injection nozzle reaches into one mold portion and a movable core reaches into the other mold portion preferably in such a position that the injection nozzle and the movable core face each other across the flexible webbing. The core distributes the injected plastics material into both mold portions and so that the plastics material must move primarily through the holes or interstices in the webbing.

Abstract: An apparatus for jointing CV cables includes a lock mechanism which closes a split portion of a mold, used for extrusion-molding and opens the split portion by heat when crosslinking is performed.

Abstract: In order for a coil winding head, preferably to be reinforced by the baked-lacquer process, to be compression-molded with no need for preliminary pre-positioning by tape-wrapping and with no damage to the winding wires, a form shell apparatus is provided with a form core, which radially confines the coil end forms shape on the inside, with a radially advanced confining form shell divided into at least two parts in the circumferential direction. This multi-part shell radially confines the coil end turns on the outside. A compression form shell axially advanceable against the coil end turns confines the coil end turns in an axial direction. It has, on its inner and outer circumferential surfaces, integrally molded guide fingers, which extend axially in the direction of the coil end turns to be shaped. Corresponding guide grooves are molded into the form core and the confining form shell, into which guide grooves the guide fingers extend.

Abstract: Electrical components permanently applied to terminal carrier plates are cast with casting resin in a casting mould. The mould includes (a) a lower mould component, provided with a silicon rubber layer containing recesses for receiving the carrier plates, (b) a central mould component which is to be clamped down onto the lower mould component and is provided with chambers which are open at the top and at the bottom and which accommodate the electrical components to be cast, and (c) an upper mould component which is provided with flow openings for the common casting resin sprue. The invention can be used, for example, in the production of small annular core coils which are later to be used in film circuits.

Abstract: Apparatus for making lined concrete pipe in a reduced time, and provision of such pipe with reduced tendencies to rusting and liner separation, are achieved by a cartridge assembly movable to and away from the pipe machine, a work stand assembly for positioning the cartridge to receive a liner, liner tensioning structures and liner to cartridge clamps for moving the liner to the cartridge, tightening the liner, and holding the liner during transport by the cartridge, and tension bars controlling wire tension during pipe formation. Concurrently with operation of the standard pipe machine, the work stand operates to place a liner on the cartridge. During the stripping cycle of the pipe machine, the cartridge delivers the liner to the core. During the pipe machine vibration under pressure cycle, the tension on the liner tension wires is relieved.

Abstract: An apparatus for impregnating porous samples for materials evaluation with an inert material which fills the pores of the samples. A plurality of samples are placed in mold cups on a rotatable table within a vacuum chamber, and a supply of impregnant or encapsulant material such as an epoxy resin is provided in a container mounted on a tiltable platform located above the rotatable table. A plurality of samples are thus mounted in respective molding cups spaced in a circle on the rotatable table, a supply of encapsulant material is provided in a cup placed in a cup holder on the tiltable platform, a vacuum is created within the chamber, and the table is intermittently rotated to position each molding cup with its sample in line with the tilt axis of the tiltable platform to permit tilting of the encapsulant cup to pour a supply of resin into the molding cup.

Abstract: Apparatus for fabricating a cushion contoured and fitted to the sitting support surfaces of a user includes a generally flat plate having a plurality of apertures in the upper surface thereof. Each aperture is coupled to and continuous with a duct within the flat plate, with all of the ducts coupled to a vacuum source by appropriate fittings and hoses. Mounted to the upper surface of the flat plate and in sealed engagement therewith are a plurality of rails arranged so as to form a generally rectangular structure, or form, open at the top and closed about its lateral periphery. A plaster positive having a generally flat lower surface and an upper surface conforming with the support surface to which the cushion is to be fitted is positioned within the rectangular form and a flexible, nonporous membrane is positioned over the open form and in contact with that portion of the flat plate therein as well as with the plaster positive.

Abstract: A pre-shaped aluminum plate is held against the flat end wall of an inverted mold cavity by vacuum pressure communicated through bore holes in the wall leading to a vacuum chamber in the mold body. A high temperature PTFE gasket shaped to match the plate fits in an annular recess in the wall to provide a seal between the wall and plate. Polyurethane foam expands and hardens in the mold cavity to further press the plate against the wall and to form a foamed plastic water ski having a flush aluminum deck. The mold cavity has a curved side wall to produce a ski having a radiused edge about the deck.

Abstract: A press with a plurality of injection plungers, which can be used to enclose integrated circuits in plastics packages, is provided with additional compensating pistons. The lower ends of the compensating pistons and the upper ends of the injection plungers project into a filling pot in which the plastics material is molded. The injection plungers force the plastics material in the injection mold through channels into cavities provided in the mold. When a predetermined pressure P.sub.k is exceeded, the compensating pistons retreat, so that a pressure drop and, thus, pressure limitation occur. In this manner, scrap would be avoided even if too large a quantity of plastics material were placed in the filling pot.

Abstract: A decorative fitting having an internal layer as well as a method of fabricating it are disclosed. Preferably, the color layer is a very thin color wall dimensioned so that when it is viewed at one angle it gives the appearance of being a solid wall, yet when it is viewed at another angle it is substantially transparent. To make the color wall, one preferably forms a frame on a first substantially transparent panel such that the frame projects out from the first panel surface. One then abuts a second substantially transparent panel against the frame so as to form a color material insert cavity point, one injects a flowable colored material/adhesive mixture into the cavity and permits the colored adhesive to harden and bind the panel walls together. Thereafter, one cuts the transparent panels into a multiplicity of handle components by cutting the walls along lines partially transverse to the color layer. This forms multiple handle components which are a sandwich of the walls with the color layer in between.

Abstract: A generally planar object 22 subject to dimensional variations is centrally held in a mold by a deformable suction ring 20, and inflatable seals 8, 9 are urged against its opposite peripheral surfaces to define a cavity 17 for the injection molding of a precisely dimensioned edge frame 23. The dimensions of the rigid mold halves 2, 3 and the elasticity of the ring and seals are such that a wide range of dimensional variations may be tolerated in the object, which may be a curved automobile glass panel, a printed circuit board, etc.

Abstract: The base mold is made from a single sheet of plastic material and is adapted to receive a specimen and either (1) a tissue processing cassette, or (2) an embedding ring. A fluid/solid fixation material is poured into the base mold and allowed to solidify in order to fix the specimen to and adjacent an outer bottom surface of the cassette or the embedding ring while the cassette or embedding ring is being supported by the base mold. The base mold includes a cassette/embedding ring supporting panel and a tissue receiving receptacle integral with and depending from the supporting panel. The base mold further includes a support formation integral with and depending from the cassette supporting panel. The support formation extends at least part way around the receptacle and includes a lower edge disposed in one plane to provide a sturdy supporting edge for supporting the base mold on a planar surface.

Abstract: A moulding apparatus and a method of moulding for components of unvulcanized elastomeric material which forms a spew free component and provides for handling the component for subsequent use. The apparatus as shown in the Figures comprises a first mould member having a mould cavity for part of the component and a feed port for material and a second complementary mould member which includes a detachable component carrying insert. The two mould members and are relatively movable to provide two different volumes for the mould cavity, the change to the smaller volume being used to return some material through the feed port and to complete moulding of the component.

Abstract: The ear plug (40) includes an elongate body with a rounded tip portion and of an elastic material enveloped by a deep-drawn sheath (41) of thin flexible plastics film material. Rearwardly the plug preferably has a neck portion from which the sheath projects in the form of a stiffer collar or flange. Production of the ear plug includes deep-drawing a thermoplastic film or foil into a sheath with desired thickness distribution, and filling the sheath with elastic material (53). Filling may take place simultaneously with deep-drawing, the body of elastic material constituting a die for deep-drawing in a forming hole (45), or after the deep-drawing. In the latter case, an elastic die body is used to advantage, the shape of which generally corresponds to that of the finished plug, for deep-drawing in a forming hole suited to the die body.

Abstract: A method and apparatus or system for the continuous manufacture of building element consisting of a self-supporting framework of tightly compressed solid particles and a foaming material in the shape of a foamed plastic material, includes the use of a filling station where mold bottoms are placed in series on a roller conveyor, assembled with sidewalls and passed along a guide section, wherein particle-shaped filler is supplied from a silo while premixed foam material is injected into the material through nozzle tubes and the components are mixed before being injected into the mold and compressed. After placing of a top wall on each of the molds, these are passed under a roller conveyor, and while the molds are moved ahead between the roller conveyors and possibly roller conveyors outside the sidewalls, the foam material binds the particles together to form a monolithic unit which will set before the molds leave the roller conveyors.

Abstract: The invention provides a device for supporting a mold insert in space inside a mold cavity. A pilot and keeper assembly rests on the top of a mold part and extends into a mold cavity and through a small hole in the mold insert. Movement of a handle, which is part of the pilot and keeper assembly of the mold part, is transmitted through a shaft to a retaining means, which engages the opposite extremity of the hole to retain the insert in position during molding operations. After plastic is inserted into the base of the mold cavity and a sufficient curing time has transpired, the handle is rotated back to its initial position, thereby returning the retaining means to a nonretention position, and the pilot and keeper assembly is withdrawn from the mold.

Abstract: Moulding equipment in which cooperable male and female connectors of a mould and a dispensing container for mouldable material have means to lock them together. This includes a locking member which is manually moveable in pivotal fashion upon one connector into and out of a locking position with the other connector.Opposing surfaces of the locking member and the other connector relatively move across each other during movement of the locking member while offering sufficiently low resistance to movement to allow for manual operation. During transfer of the material into the mould, the opposing surfaces are urged together by moulding pressure to increase resistance to movement of the locking member out of the locking position. In preferred constructions, the locking member has a cam surface which ensures the need for a progressively increasing unlocking force to enable release of the locking member during transfer of the mouldable material.

Abstract: A method and an apparatus for producing concrete articles, such as shaft rings, with projecting elements such as climbing irons or stirrups, by means of an automatic inserting mechanism which removes the climbing irons from a magazine and automatically inserts them into a mold core. These climbing elements are guided automatically to a core segment and are brought into housings therein during a time interval between the ejection of a completed concrete article from the mold cavity in a first working cycle and the next following work cycle in timed overlap with carried out work steps during this time interval. This automatic process takes place while the operator withdraws and takes away a completed article from the machine at the end of a work cycle and prepares the machine for the next work cycle. This leads to equally short machine cycle times for completion of concrete articles with or without climbing elements.

Abstract: The invention relates to superficial molding on glass sheets, by injection molding of plastic material.According to the invention, a glass sheet 1 is inserted in a mold comprised of two plates and which define a generally planar junction surface wherewith one part of the mold, which part is delimited by a hermetic seal, is evacuated, which enables the central part of the glass sheet to be held in place, and according to a feature of the invention, the superficial molding is delimited by a molding seal which is capable of accommodating variations in the shape of the glass sheet and which can withstand the pressure associated with the injection molding of the plastic material.

Abstract: Apparatus for making a molded plastic roller with embedded bearings. The roller is formed directly on a bearing or the like by injecting plastic into a mold by way of an umbrella sprue. The tool parts are arranged so that the shearing surface, formed after shearing off of the sprue residue when the mold is opened, is located on the outer surface of the inner collar portion. The molding tool comprises two tool parts for forming the outer surfaces of the rolling body, at least one tool part having a molding portion for forming an annular recess in the roller, and a cylindrical tool part inserted in the bearing, or the like and having a mushroom-shaped head. A back taper of the molding portion for forming the annular recess and the edge of the head together define an annular clearance through which plastic material is injected.

Abstract: Capsules in which histological tissue samples are prepared for embedding and in which the samples are embedded include a first and a second member, at least one of the members including a frame that defines an opening. The members have complementary surfaces for establishing peripheral contact between the members around the opening. A porous material is spread across the opening so that when the members are in peripheral contact with each other, a tissue-holding region is defined inward of the porous material. The porous material has a porosity that accesses processing liquids and liquified embedding material, such as molten paraffin, but prevents stray parts of the tissue from floating free of the region. Preferably, the second members also comprise a frame defining a second opening and porous material spread across the second opening.

Abstract: A method and an apparatus for continuously filling grooves in metal sash bars with heat insulating synthetic resin are disclosed. The method comprises the steps of closing the opposite ends of the groove of each of the metal sash bars by end caps each having an end wall with a thinned top edge; continuously moving the metal sash bars through a path below an injection device with the grooves facing upwardly and with at least the top edges of the end caps of one preceding sash bar and the succeeding sash bar in close contact with each other on the upstream of the injection device; and continuously injecting a solution of the heat insulating synthetic resin from the injecting device into the grooves of the sash bars at a constant injecting rate while continuously moving the sash bars.

Abstract: An encapsulation mold has slanted support walls which accommodate a plurality of units that are to be encapsulated, and a runner system for effectively distributing plastic to chamber adjacent the areas of the units that are to be encapsulated.

Abstract: A tissue specimen processing capsule is provided which includes a pair of interlocking frames each having a porous web spread across its central openings for holding specimen in a region defined between the webs. The porous webs permit access to the specimen by processing and impregnating liquids. After the tissue specimen is processed, it is removed from the capsule and placed in a mold depression, and the empty capsule is placed over the depression. Molten casting material is poured into the mold to fill the depression and to cover the porous material. The molten casting material solidifies to form a tissue block with the capsule serving as a clampable base for an outwardly extending, tissue-containing portion. The capsule may be formed in a single operation in an injection molding process using a press that includes a pair of mold blocks that together define frame-forming cavities and between which is sandwiched a segment of an elongated web of porous material.

Abstract: This relates to the mounting of a label magazine in a manner wherein labels carried by such label magazine may be rotated or slewed about a line extending axially of the label magazine through the center of a label. The slew control device is used to effect such rotation and thus orientation of a label so as properly to position the label for transfer. In the preferred usage of the slew control device, each label is transferred into a blow mold half and proper orientation of a label with respect to a blow mold half cavity is obtained utilizing the slew control device. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

Abstract: A mold includes relatively movable mold sections which defines multiple cavities and a space between two of the mold sections when the mold is open. The plurality of flexible strips each carrying a heat responsive transfer material are directed through the space and are clamped adjacent the mold cavities when the mold is closed. A plastics material is injected into the cavities to form the articles and to engage the transfer material to form predetermined artwork on the articles within the cavities. When the mold is open, the articles are removed, the strips are pulled through the space to advance new transfer material to the mold cavities, and the cycle is repeated. In one embodiment, the strips carry the transfer material at longitudinally spaced intervals in the form of the desired artwork, and in another embodiment, the artwork is formed by a template attached to the movable mold section adjacent the cavities.

Abstract: A molded body having a profiled cross-section, such as a grinding or polishing tool, is cast in a mold by pouring foaming synthetic material into a molding cavity closable on all sides except for holes in the end walls of the molding cavity through which a contouring insert member having a profiled surface extends to pass through the entire molding cavity and possibly even through several molding cavities arranged in axial alignment with one another. A sealing device (22) is provided adjacent each end wall for closing and sealing the profiled gap between the contouring insert member and the hole in the adjacent end wall. The sealing devices are adjustable to differently profiled inserts and assure that a molded body or tool is produced which has precise, prismatic and parallel surfaces and edges.

Abstract: Apparatus for high volume preparation of cross-sectional specimens of printed circuit boards for microscopic examination, including a method and apparatus for precision mounting of a large number of such cross sections in a single molding sequence for simultaneous polishing of such cross sections in a single polishing operation.

Abstract: A machine for molding and curing a mass of resilient material into a desired shape in one operation and, if desired, bonding the resilient material to another material in the same operation; generally in the class of molded rubber or rubber-like goods and particularly in the class of self-cooling airless wheels for vehicles, which wheels contain holes that taper inwardly from the periphery of the tire to and/or through the rim. The machine is characterized by fin compressor boxes that impel fins into a mold cavity to cause a compressive reaction on resilient material therein, thereby expelling excess air from the mold through escape holes. An air passage may penetrate the fins for air or water to be circulated therethrough to aid in heating, cooling and/or curing the product. Withdrawal of fins from mold cavity permits easy removal of cured product.

Abstract: A tubular container is molded with a cap by defining; at least one portion of a cavity for molding a neck portion between a female die for receiving a cap having a screw on the inside thereof and a male die having a fixed guide rod for insertion into the cap centrally thereof. A top end portion of a preformed container body is partly inserted into the cavity. A synthetic resin, which possesses compatibility with the container body and is not fused together with the cap, is injected into the cavity to form the neck portion integrally with the container body.

Abstract: An apparatus is disclosed for centering a reinforcing mesh which is in a pipe or conduit form for manufacturing reinforced concrete pipe or conduit. In order to automatically center the reinforcing mesh in a simple and reliable fashion, a plurality of mesh centering units are provided which are distributed at spaced intervals around the perimeter of the form. Each of these units comprises at least one radially outwardly extending member which penetrates through a receiving slot into the form to a depth which is adjustable depending on the external diameter of the reinforcing mesh. When the concrete introduced into the form is compacted, the member can be retracted to an inactive position from the operating position, in which it biases against the centered mesh.

Abstract: A mold assembly for molding a cushion article, such as a seat cushion or the like, for snapping in place onto an appropriate seat support without additional attaching means. The seat cushion has a foam body with a snap-ring member molded integral with a peripheral portion of the body, the snap-ring member providing means for snapping the seat cushion over the seat support. A mold assembly is disclosed for molding the seat cushion, utilizing the snap-ring member as an integral part of the process, and a mold assembly to evacuate entrapped air from the mold cavity.

Abstract: A tubular container molding method includes the steps of inserting a core block having an upwardly projected annular flange at the top end into a preformed tubular member, closing the mold and thereby pressing an upper marginal portion of the tubular member against a cavity mold and bending inwardly such upper marginal portion to form a shoulder portion of the container, urging the inwardly bent marginal portion against an interior surface of the cavity mold by the annular flange to hold the shoulder portion between the core block and the cavity mold, and injecting molten resin into an air gap defined between the core block and the cavity mold, thereby molding conical and neck portions of the container integrally with the shoulder portion.

Abstract: A combination long lower mold and pretension bench for the formation of prestressed concrete materials is constructed by serially connecting plurality of unit lower molds of concrete, attaching prestressing steel wire tension benches one each to the foremost and rearmost unit lower molds, and fastening the unit lower molds and the tension benches collectively with steel wires. Prestressed concrete materials are obtained by stretching prestressing steel wires along the upper surface of the long lower mold, continuously pouring and placing stiff-consistency concrete on the long lower mold, causing a slide upper mold to run on the concrete thereby shaping the concrete in a required cross section, curing the shaped concrete strip, and cutting the cured concrete strip into pieces of a desired size.

Abstract: A method and apparatus associated with plastics material applied by injection moulding to a metal substrate by surrounding at least a portion of the substrate with a mould and injecting flowable plastics material into the mould, characterized in that the method and/or the apparatus utilizes locally induced heat in the portion of the metal substrate surrounded by the mould to bond and sealingly adhere the plastics material to the metal substrate in total surface-to-surface contact.

Abstract: A pre-shaped aluminum plate is held against the flat end wall of an inverted mold cavity by vacuum pressure communicated through bore holes in the wall leading to a vacuum chamber in the mold body. A high temperature PTFE gasket shaped to match the plate fits in an annular recess in the wall to provide a seal between the wall and plate. Polyurethane foam expands and hardens in the mold cavity to further press the plate against the wall and to form a foamed plastic water ski having a flush aluminum deck. The mold cavity has a curved side wall to produce a ski having a radiused edge about the deck.

Abstract: A unitary molding insert (24) and pin (27) of the prior art are replaced by an improved molding insert (30) which is provided with a plurality of collapsible pin assemblies (56), each including a unitary hollow, cylindrical boss (58), and a separate piston (60) having a unitary valve (62) and pin (64). Each piston (60) may be inserted in its boss (58) with its valve (62) being seated on the upper edge of the boss (58) and with its pin (64) engaging the inner surface of a mold (84) to maintain the insert (30) in a stable position during the encasing of the insert (30) with a suitable molding material. When the mold is substantially filled to capacity, the pressure created by the molding material will force the piston (60), valve (62) and pin (64) to a recessed position within the boss (58).