Abstract: Method for uniting a plastic fixation part with a sealing body comprising a head end and a sealing sleeve, by first molding the sealing body and subsequently molding the plastic fixation part around the head end of the sealing body, thereby protecting the sealing sleeve. The fixation part is provided with corrugations for connecting said fixation part with a socket pipe provided with corrugations on its outer side.The method may be carried out in an apparatus comprising a first mold part, a second mold part and a third mold part forming together a molding space for forming the sealing body and a forth mold part replacing the first mold part, forms a molding space for molding the fixation part.

Abstract: The invention relates to a coupler for insulated plastic pipe ends and a branch pipe end, the insulation being covered with tubular casings. The coupler is provided with anchoring means comprising one or more ribs or cams extending laterally from the central coupler 1 and with means for transmitting pressure forces from the anchoring means and the central coupler to the tubular casings.

Abstract: A device and method for recovering heat from the soil and groundwater, comprise heat-exchanging means consisting of an inner tube, an outer tube and partitions forming longitudinal channels between said inner and outer tube.An inlet for heat-exchanging fluid and an outlet for heat-exchanging fluid are present for conveying a heat-exchanging fluid through said longitudinal channels.The heat-exchanging means are preferably placed in a perforated casing allowing passage of liquid but not of soil particles. The casing consists preferably of an outer casing tube and an inner casing tube, casing partitions providing longitudinal casing channels. For allowing passage of groundwater the outer casing tube and the inner casing tube are provided with perforations.Heat is recovered by passing a heat-exchanging fluid through the casing channels.

Abstract: A method of making seals in tubular web provided with side gussets, in which method, after making the seals, sensors for the inner gusset edges are withdrawn outwardly over a certain distance, the position of the sealing devices remaining unchanged, and after transport of the tubular web, the sensors are moved inwardly again and the new position of the inner gusset edges is observed, subsequently, when a difference is observed as compared with the previous time, the position of the sealing devices is brought into correspondence with this observation before making the next seal.

Abstract: A plastic crate or tray comprises a bottom and vertical side walls. A side wall comprises inner and outer side wall parts.Injection molding points are present in the lower edge of the outer side wall parts.

Abstract: Apparatus for making profiled plastic tube and comprising two circulating endless chains, each making a plurality of mold halves move along with a tube coming from an extruder, these mold halves pairwise constituting a mold cavity in which the tube is being given its profile. According to the invention the molds are movable relative to the chain links in a direction perpendicular to the direction of movement of the links. The machine frame is provided with guides for the mold halves, some located interiorly, others exteriorly, with respect to the chain loop, such that once closed, the cavity formed by the pairs of mold halves will remain closed and undisturbed up to the end.Preferably the transitions between curved portions and the operative portion of the path of the mold halves at the entrance and the exit ends are bending points of mathematically calculated paths and the operative straight path tangentially joins said transitional portions.

Abstract: A plastic coupling pipe part for connecting corrugated plastic pipe comprises abutment projections and a radially resilient displaceable lip, carrying an inwardly directed cam. The lip is surrounded by openings delimited by a rectangular incision in the plastic pipe. The transition part connecting the lip with the pipe wall has a smaller width than the end edge of the lip.In a pipe connection with such a coupling pipe part the coupling cam engages a flank of a wave valley of a corrugated pipe.

Abstract: A branch pipe part is provided with a collar and a downwardly extending skirt, the free end of the branch pipe part comprising a first outwardly extending projection and the lower portion of said pipe part being provided with longitudinal incisions allowing deformation of said lower portion.The outer wall of the space formed by collar and skirt may have apertures for passing a lip of a sealing member. In order to avoid further deformation of the lower portion with incisions after connection with a main conduit, a deformation-preventing bush is pushed into the lower portion and locked by means of a cam.For decreasing the distance between the outer side of a main conduit connected with the branch pipe part, the skirt may be provided with a removable adapting ring, an intermediate part thereof decreasing the distance between the outer side of the main conduit and the free lower end of the skirt.

Abstract: An adhesively joined pipe connection comprises a male pipe part and a female pipe part of fiber reinforced plastics, both being provided with a foam plastic insulating layer. The foam plastic layer extends to the front end of the receiving portion of the female pipe part, a heating resistance foil being fixed to the outer side of said receiving portion by means of an adhesive. A sealing sleeve engages sealingly the outer side of tubular casings of the foam plastic layers upon the female and male pipe parts. Connecting wires connected with heating foil extend through the foam plastic layer.A female pipe part of fiber reinforced plastics provided with a foam plastic layer is extending to the free end of a receiving portion and a heating resistance foil fixed to the outer side of said receiving portion. Wires connected to the resistance foil extend through the foam plastic layer.

Abstract: Tube of thermoplastic material, comprising longitudinal channels of rounded cross section and having such wall stresses that, after axially cutting the tube, the edge parts beside the cut edges overlap each other for less than 5% of the outer circumference of the tube.

Abstract: A plastic bag provided with a filling valve and a gas permeable dust filtering pocket opposite said valve, allowing gas to escape from the interior of the bag.A disconnectable spot adhesive connection exists between a layer of said pocket and the adjacent bag wall parts opposite a corner flap. An additional adhesive or welding connection may be present near the free end of the pocket for connecting the layer with the bottom flaps.

Abstract: A method and device for cooling molds circulating in a horizontal plane, in which siphon action is used to pass cooling liquid from a top gutter through the molds. In this way the whole cooling system is becoming constructively simplified, such that production speeds can be increased, with the consequent greater length of the cooling system, but without its becoming unduly complicated. This effect is realized irrespective of the nature of the machine or the number of molds.Method and device are especially advantageous when applied with the manufacture of plastics tube, more particularly yet with the manufacture of plastic corrugated tube.

Abstract: An apparatus for installing a sealing ring in a groove chamber of a socket by impressing said sealing ring comprising a sealing ring impression member and sealing ring retaining means for maintaining the sealing ring in the impressed state said retaining means comprising two axis with flat sides.

Abstract: The invention relates to a pipe part with a socket being provided with longitudinally extending channels. The channels extend into the wall of the socket. The socket engages a J-shaped retaining ring which forms with the socket a recess for retaining the flange of a seal that includes a sealing sleeve. The retaining ring adheres to the outer side of the socket by an adhesive.

Abstract: A plastic pipe comprises an inner wall and an outer wall, being integral with longitudinal partitions betweem them and bounding longitudinally extending channels and a circumferential, helically or non-helically extending groove, which groove has been formed by closing the channels by pressing channel wall parts onto each other. A retaining ring may be snapped into an external groove.

Abstract: Method for connecting thin-walled plastic tubes by heat welding wherein a normal plastic tube is heated and provided with a funnel-shaped widening and another tube is heated and provided with a conical narrowing, the narrowing being pushed into the funnel-shaped widening so that these parts are heatsealed to each other.

Abstract: The raised edge part of a deep-drawn plastic cover is printed by pressing a carrier of a resilient deformable material, carrying a coloring composition, against the raised edge part.An apparatus for manufacturing the plastic cover comprises a deformable carrier for carrying a coloring composition. The carrier is integral with a cylindrical part connected with a first cylinder. Two concentric cylinders, positioned around the first cylinder at either side thereof, deform annular parts of resilient material and press these annular parts against the raised edge part when, on the one hand, the first cylinder and, on the other hand, the two concentric cylinders are moved with respect to each other.The coloring composition may also be carried by a layer-shaped carrier material.

Abstract: A socket of a thermoplastic pipe is provided with an internal groove by subjecting the tube to an upsetting action and simultaneously inflating the tube by an inner pressure. Subsequently a moulding ring is expanded and the tube is shrunk onto the expanded ring by cooling. Before shrinkage the inner diameter of the bottom of the groove is at least equal and preferably greater than the outer diameter of the moulding ring in expanded form.

Abstract: A composition of polyvinylchloride containing the usual additives and a plate out preventing, chemically or physically acting drying agent. The drying agent is preferably an expanded and finely ground aluminiumsilicate, having a high oil absorption and water absorption and preferably low amounts of earth alkaline metals. The plate out preventing drying agent is incorporated in a normal additive composition in order to avoid handling of voluminous masses of drying agent. This incorporation is executed by mixing with a mixture of additives or during the chemical reaction for preparing the additive composition.

Abstract: Plastic pipes comprising an inner and outer wall being interconnected by lengthwise extending connecting partitions, forming channels, the ends of the channels being each separately sealed by sealingly pressing the end walls of a channel to each other after these walls have been heated to a temperature surpassing the plasticizing temperature.