Abstract: A method and apparatus for manufacturing a building block by molding under pressure a mixture of a hydraulic binder such as plaster, an inert filler such as sand, and water, by passing a mold (50) through various stations, including a station (A) for filling the mold with a measured quantity of the mixture (56), a station (B) for installing a mold top plate (38), a station (C) for compressing the mixture in the mold, a station (D) for keeping the top and bottom plates (38, 40) in place in the mold, a station (E) for withdrawing the top plate (38), and an unmolding station (F).

Abstract: A method of manufacturing an open top, walled member for containing a molten metal, especially a flowing molten metal or reconstructing a worn or damaged member. The method includes the step of forming the inner walls of a mold which define the inner surfaces of the walled member of an open metal mesh screen which is meltable by the molten metal which is to be contained. The next step is to transfer, usually by pumping, an alumina-silicon carbide casting compound into the space between the open mesh metal screen and the outer walls defining the mold, which outer walls may be in situ structures. If an existing walled member is being repaired, any damaged or worn portions of the existing walled member are removed and the casting compound is poured in to replace these portions. The next step is to apply heat to dry the casting compound while the open mesh screen of the mold remains in place in contact with the casting compound.

Abstract: A process for manufacturing a flue made of fiber-reinforced plastic (FRP), particularly of a stack for discharging chemically aggressive fumes, consists of manufacturing the FRP flue directly inside the stack. The apparatus for performing this process includes a rotating carousel which supports a first work station, a second work station and at least a third work station to progressively and constantly deposit on a stationary mold at least one first layer of chemically-resistant material and at least one layer of mechanically-resistant material in order to form, without discontinuities, a central portion of the flue of the stack.

Abstract: A method of manufacturing hollow molded articles having a beautiful surface at a low cost and by a simple and efficient process includes providing a hollow elastic molding die made of an elastic film and having an opening port, feeding a material to be molded of an amount smaller than the internal volume of the elastic molding die into the elastic molding die through the opening port, closing the opening port, solidifying the material to be molded while the elastic molding die is rotated to all directions, and parting the solidified hollow molded article from the elastic molding die. Arrangement for preventing the elastic molding die from being deformed while it is rotated to all directions includes holding it firm by a solid holding member conforming to the external shape thereof or by positioning it in a fluid or powdery material holding member.

Abstract: A slip casting process and apparatus for producing parts with graded properties across the thickness of the body of the parts. A number of slips is combined at a varying predetermined ratio and passed continuously through a casting mold between its inlet and outlet. The process can be carried out under elevated pressure. The casting mold can be positioned vertically or horizontally.

Abstract: Apparatus and method for constructing a manhole collar between an existing manhole cone and a precast manhole ring. The apparatus includes a circular slip form tube, tapered from a larger top diameter to a smaller bottom diameter; at least two support arms, radially extending from adjacent the top of the slip form tube for placement on a support surface, such as a road surface, to hold the tube at a selected height relative to ground level within a manhole cone; and a plurality of fasteners for attachment of a precast manhole ring about the exterior periphery of the slip form tube for supporting the ring at a selected height relative to the manhole cone and the roadway surface. The apparatus may include a concrete spill retention ring, placeable upon the top rim of the manhole cone and around the slip form tube to prevent concrete from entering the manhole cone.

Abstract: Process for the production of concrete tiles by cutting a block of concrete mixture, characterized in that the block of mixture is subjected to a preliminary curing at room temperature for a duration of at least 24 hours or to a low-pressure steam treatment at a temperature <100.degree. C. until the compression strength reaches a value of at least 20 MPa, and to a second treatment with steam in an autoclave. The cement tiles thus obtained may be bonded to the floor using a normal setting layer of cement mortar, without giving rise to any problems of detachment.

Abstract: An auto body shaping and smoothing tool includes an elongated handle with a blade mounted along one edge thereof. The blade includes fine teeth which are used for shaping auto body filler material. In the method the filler material is allowed to dry to a semi-hardened state which is still shapeable. The tool is drawn across the material to shape and smooth it prior to full hardening. Once the material has reached a fully hardened state, final sanding takes place.

Abstract: An injection molding process includes using a mold provided with a resin reservoir having a retractable piston and protruding from a mold cavity in at least one of divided resin passages ranging from the point where the injected molten resin is divided into two streams to a weld formed by the union of the resin streams, feeding the molten resin into the mold while the piston is in a retracted or advanced state to form the weld, and either advancing the piston toward the mold cavity side to force the resin from the resin reservoir into the cavity or retracting the piston to withdraw the resin from the cavity side into the resin reservoir so as to cause the migration of the resin in the weld to thereby force the resin on one side of the weld into the resin on the other side, thus reinforcing the weld, and which is capable of remarkably improving the strength of the weld and its periphery of a molding which otherwise forms a weld having an extremely low strength.

Abstract: A mold for forming an open top, walled member having side walls and a bottom surface for containing a molten metal. The mold including an inner screen having a plurality of openings having inner side walls and a bottom surface. The mold further includes an outer wall, wherein the inner screen and the outer wall are spaced relative to each other to define a space so that the side walls and the bottom surface of the open top, walled member are formed therebetween.

Abstract: A seam construction for a papermakers fabric in which mating seam components are molded onto opposite ends of the fabric. The seam is assembled by matingly engaging the seam components molded onto the respective fabric end to define a seam having a caliper substantially equal to the caliper of the fabric. Preferably, the seam components are male and female and become positively locked when the seam ends are joined together.

Abstract: A method for making, clean, bughole-free hardened cement structural units, including the steps of a) applying a release agent to the surface of a form; b) preparing a cement composition; c) adding to the cement composition a water-soluble polymer dispersant and a solution viscosity-reducing agent; d) placing the cement composition of step c) into the form, e) curing the cement composition of step c) to form a hardened structural unit, and f) removing the structural unit from the form.

Abstract: An interlocking checker brick used to form a checkerwork for use in recovering heat in thermal regenerators and recuperators. The checker brick is made of a refractory material and is of a generally trapezoidal shape with each side wall having at least a section forming an acute angle with respect to the base. The preferred brick has spaced side walls each of which includes top and bottom sections adjacent to and perpendicular to top and bottom surfaces respectively. Each side wall also includes a central section flaring outwardly and downwardly from its top to its bottom section. Checkerworks utilizing these bricks increase turbulence while reducing laminar flow during alternating cycles of flowing gases and air.

Abstract: A method of making a blow-molded container from a strain-hardenable polymer, the container having deep recesses for secure "post mold" attachment of a handle. The container is formed in a modified blow mold having retractable blades. The blades are partially extended for blow molding partial recesses, and then further extended for mechanically forming the deep handle recesses. The mechanical forming operation overcomes the stretch limits imposed by strain-hardening of the plastic material during blow molding, and the "post-mold" attachment of the handle provides a reduced cycle time and lower level of defects compared to the known "in-mold" handle forming operations.

Abstract: A cover for an air bag unit having a patterned tear seam therein defined by an integrally bonded, thermoplastic filler strip as the cover material and including a material having properties different than that of the cover material. Apparatus for forming the cover includes a thin shell mold having an inner surface that is heated to melt thermoplastic material cast thereon. A powder box adapted to contain thermoplastic material therein for distribution onto the thin shell mold carries a gasket having a shape corresponding to the tear seam shape. The powder box and gasket are adapted to be connected to the thin shell mold for forming a sealed footprint on the inner surface during distribution of the cast material against heated surface portions of the thin shell mold to form a thermoplastic cover with an opening therein that has the tear seam pattern. The opening is later filled with the lesser strength thermoplastic material to form an integrally bonded thermoplastic filler strip.

Abstract: A construction method for one-step grout fixed window frames on external walls of a concrete-structured building includes the following steps. A window frame including vertical and horizontal sections is fixed with vertical lining boards to the inner side of its vertical sections to form a window frame assembly, and is then supported on an upper supporting board which has been securely attached to a concrete template of an external wall of the building. Template sealing strips are separately attached to an exterior edge and an interior edge of the vertical sections and the upper horizontal section of the window frame assembly, so that a complete moulding cavity is formed. Into this moulding cavity the grouting concrete is grouted and the window frame is inlaid in the concrete after the concrete is set and the concrete templates are removed.

Abstract: A method of forming a shell structure using rotary moulding techniques where two halves of the shell are moulded together and then joined when the two halves of the shell are in a molten state. The method is particularly useful for moulding one-piece boat hulls.

Abstract: An appliance door particularly suited for use as a refrigerator or freezer door includes a hollow, blow molded door slab, and a food storage shell or casing projecting from one wall of the slab. The parts forming the shell are prepared in a first step, e.g., by blow molding, and then are removably mounted as inserts in registering recesses formed in the bottom of the cavity of one of two plates or sections forming the mold for the door slab. The two mold sections are then closed over a tubular, plastic parison which is then inflated to form in the mold the hollow door slab, portions of one wall of which mold over and around a series of male projections which extend into the mold cavity from the mold inserts, thus causing the shell to be molded to and to project from the slab upon subsequent opening of the mold sections and removal of the slab therefrom.

Abstract: A method and apparatus for producing a hollow article having a blow molded portion and a compression molded portion. Plastic is extruded over a blow pin assembly to form a parison having an open end and a diameter larger than the diameter of the article's mouth. The blow pin is movable relative to the parison and includes a male mold member on its end. The male mold member has a molding surface corresponding in shape to the compression molded portion of the article. A cutting member is also provided on the blow pin. The cutting member is also movable relative to said parison. Once the parison is enclosed in a hollow mold, the male mold member of the blow pin compresses a portion of the parison between the second portion of the hollow mold and the molding surfaces of the male mold member so as to form the compression molded portion of the article.

Abstract: An amount of resin necessary for lining an inner surface of a pipe is calculated. A lining pig is inserted in the pipe from an open end thereof, and the calculated amount of resin is supplied in the pipe from the open end subsequent to the insertion of the lining pig. A blocking pig is inserted in the pipe behind the resin, and a pressurized non-compressible liquid is supplied in the pipe subsequent to the insertion of the blocking pig thereby feeding the charged resin through the blocking pig until a front end of the resin reaches an inner end of the pipe. The resin is sucked together with the lining pig and the blocking pig so that the inner surface of the pipe is lined with the resin.