Abstract: An improved method for manufacturing a foam-filled polyurethane foam bun from foam particles having uniformly dispersed therewith large amounts of solid material bonded together with new polyurethane foam is described. The method comprises uniformly applying a liquid flexible polyurethane foam-forming material to a dispersion of foam particles and solid material to provide a blend, distributing the blend within a mold, and foaming and curing the foam-forming material by a plurality of steaming steps wherein the mold is flipped from a first to second position between steaming steps. The foam buns have a uniform density gradient. Foam buns are disclosed having a variation in density across the foam bun. There is also disclosed an improved char-forming foam obtained as a result of using boric acid in the foam-forming formulation.

Abstract: A device and method for flash suppression in a molding with rotation system having a non-rotating mating surface capable of venting gases during the molding process while simultaneously suppressing flash. Flash is directed inwardly and away from the mating surface and contained between a mandrel and mandrel housing in a low pressure reservoir which is completely separate from the mating surface. A cooling fluid is utilized to carry away flash particles from the low pressure reservoir and thereby further prevent contamination of the mating surface.

Abstract: An apparatus for forming concrete burial vaults and the like. The apparatus comprises a plurality of forms which are movable independently and as a unit in a series of operating steps to form a completed vault. Drop-in apparatus for forming a compound vault is also described.

Abstract: An apparatus and method for feeding molds to a device for centrifugally casting a plurality of axially symmetrical or asymmetrical articles such as lenses, disc valves, and the like on a continuous basis.

Abstract: A concrete and wire placement mechanism mounted for bodily movement relative to a form is provided with a tube for conveying concrete to the form and includes driven elements supported by the tube operative to feed, cut and to throw off discrete cut lengths of reinforcing wire on the order of at least 10 inches in length for embedment in axially aligned and ordered arrays in layers of concrete deposited in the form as the mechanism moves relative to the form. In one embodiment for making utility poles the concrete form is a hollow, elongated substantially-cylindrical member which is axially movable to and fro and which is rotated about its axis during axial movement thereof.

Abstract: A method of fabricating a polycrystalline silicon wafer, which method advantageously has the steps of radially outwardly flowing molten liquid of silicon base material on the wafer forming surface of a turntable mechanism by means of centrifugal force, thereby forming a thin molten liquid layer in a prescribed atmosphere, and cooling and solidifying the same. An apparatus for fabricating the wafer is used to carry out the method with a recover tray arranged at the wafer forming surface for receiving the excessive silicon liquid scattered, and a wafer tray placed on the recovery tray, and the wafer forming surface is cooled with coolant flowing in the wafer forming mechanism. Thus, large crystalline grains can be grown on the wafer in free states with the atmosphere from the inner surfaces of the casting mold as the conventional method.

Abstract: The present invention relates to an apparatus for forming centrifuged poles made of high-strength resin, which apparatus features a rotary mould in which the resin is spread on a support made of felt or the like, heating means being provided in proximity to the mould, characterized by the fact that, in its interior, said mould has guide means for guiding a delivery head which delivers said material, which head is movable to and fro and is connected by means of a hose to a resin feeding apparatus located outside the mould.

Abstract: This invention relates to an apparatus for the manufacture of conical hollow poles with an essentially circular cross-section, made of fiber reinforced synthetic resin, in which the fiber reinforcement is wound off from a carrying tube which is introduced into the mold, attaches itself onto the interior wall of the mold and is saturated by the synthetic resin which is injected into the mold from one end, with the nozzle being guided approximately longitudinally to the mold and with a light source arranged on the opposite end of the mold illuminating the interior of the mold, the inside diameter of which corresponds to the predetermined inside diameter of the pole at the pole bottom.

Abstract: A method and apparatus for manufacturing a multilayer powder blank, and the product of such manufacture which is suitable for subsequent extrusion. A hollow cylindrical container with its central axis oriented horizontally is rotated while powder is allowed to fall from a powder distribution tube in the center of the container downward onto the inner surface of the rotating wall, thereby forming successive layers of powder which are maintained in position by centrifugal forces acting thereon. The powder blank consisting of the multiple layers is removed from the container, isostatically compressed, and finally sintered, with fusion of the outer powder layers into a fused, water-tight coating.

Abstract: The invention relates to apparatus for moulding a tire for a wheel rim by means of a mould having mould parts, said mould parts being movable between a closed working position in which they enclose a mould cavity with the shape of the tire and an open position in which said mould parts are spaced apart, wherein in the open position of the mould parts a hollow tire core is positioned in the mould cavity while being receivable with respect to said parts, wherein the mould parts are moved into the working position, in which a residual cavity not occupied by the tire core is left free in the mould cavity, said mould defining the residual cavity being adapted to receive synthetic resin foam for moulding a tire body. Preferably the tire core is arranged on the wheel rim before being positioned with respect to the mould parts.

Abstract: An improved apparatus for producing concrete pipes includes a molding box and a pair of runner wheels for supporting the molding box. The box is vibrated while being rotated to disperse the components of ballast uniformly with sand and cement interposed therebetween. This apparatus makes it possible to produce concrete pipes having a higher strength.

Abstract: A method and apparatus for spin casting a castable material into a cylindrical body. The method comprises the steps of rotating an elongated cylindrical body about its longitudinal axis, applying an extrudable uncured material as a continuous stream in helical fashion from one point in the body to another point, continuing to rotate the body until the material is leveled and at least partially curing the material while continuing to rotate the body. The apparatus comprises means for holding and spinning an elongated cylindrical body, and extruder means for providing a continuous stream of an extrudable uncured material in a desired fashion along the inside of the cylindrical body.

Abstract: A method and an assembly for practicing that method wherein an article is molded of a heat-fusing material or plastisol in a mold having first and second groups of liquid passages disposed adjacent the mold surface for controlling the temperature over respective first and second areas of the mold surface. The mold is supported for rotation about an axis by a stationary pedestal. A movable module supports plastisol storage tanks, heat exchangers, valves, conduits, etc., for supplying the plastisol to the mold. The movable module also supports a dump tank which is disposed beneath the mold for receiving and retrieving the liquid plastisol which is emptied or dumped from the mold when it is rotated to an inverted position. There is included first and second liquid circuits including a pump and heat exchanger for supplying liquid at different temperatures to the passages associated with the mold.

Abstract: A smooth, plastic-lined corrugated pipe having an intermediate layer of plastic foam. The pipe is made by internally coating a corrugated pipe with a foaming mixture and pressing an expandable cylinder of plastic sheet liner against the foaming mixture until the foam solidifies. An expandable mandrel apparatus presses the plastic sheet liner into position. The apparatus comprises a hollow cylinder, an elastomeric cylinder fitted on the outside of the hollow cylinder defining an annular space therebetween and a fluid conducting means communicating with the annular space.

Abstract: A process and a device for producing concrete pipe by filling and compacting fresh concrete in an upright casting form. An outer jacket surrounding a vibrator-equipped core is rotated around its geometric axis with an internal peripheral speed which is greater than the maximum vibrational speed at which said core acts on the fresh concrete during compaction, said vibrational speed being the product of the amplitude and frequency at which the core vibrates. Around its circumference, the outer jacket has axially distributed roller paths for cooperation with rotationally journalled rollers which can be pressed against them. At least one roller is driven and is a drive means for rotating the jacket, the others being non-driven support rollers. All rollers are mounted on a frame member around the outer jacket of the casting form.

Abstract: Disclosed is a method and apparatus for forming indicia on the outside of a roto-molded plastic container during the roto-molding process wherein a template bearing a mirror image of the indicia is removably affixed to the interior wall surface of a mold.

Abstract: A molding system and method are provided together with articles produced thereby wherein rapidly setting molding material is introduced into a mold and made to conform to the walls of the mold cavity by movement of the mold prior to the setting of the molding material. Precise automatic control is effected, not only of one or more resinous molding materials but also of catalyst's employed to rapidly set the molding material and also of a plurality of power operated devices which serve to move the mold about a plurality of axes. Automatic control is also effected of power operated means for varying the operation of one or more mixing chambers, valves and the like in a preprogrammed molding cycle. In a particular form, feedback control is employed to assure the predetermined operation of the motors and power operated devices controlling the complete molding operation.

Abstract: A completely self-contained apparatus and associated technique for the manufacture of large fiberglass structures. In a preferred embodiment, the system is designed to manufacture large fiberglass storage tanks for liquids, and is self-contained from the point of view that the machine is capable of performing all manufacturing steps without any auxiliary equipment and may be set up virtually anywhere that can provide a source of electricity and air. The main components of the machine include an operator's carriage which is cantilevered from a rear frame so as to enable same to be inserted into the open end of a large, substantially cylindrical revolving mold having a closed, substantially hemispherical end portion. The carriage includes an overhead canopy for the protection of the operator, as well as fresh air intake and exhaust fans to provide adequate ventilation for the operator.

Abstract: A centrifugal casting machine (20) has a first rotatable shaft (33) and a second rotatable shaft (45) as well as a rotatable core member (100) having a central opening, with at least one of these shafts being adapted for reciprocal movement so as to extend into the core member central opening and adjacent to the other one of the shafts (33) and (45). First (73) and second (83) mold halves are located on opposite sides of the core member (100) and each is adapted to move inwardly and outwardly between open and closed positions. The mold halves (73) and (83) are rotatably supported on bearing means (75) and (85) and in closed position are adapted to rotate with the core member (100) and define a cavity (128) in combination therewith. The improvement takes the form of the addition of mold isolator means (130) and (132) between the bearing means (75) and (85) and the mold halves (73) and ( 83).

Abstract: A method and apparatus for molding concrete block products is disclosed, in which a surface layer and a back layer are formed by supplying different concrete aggregates into a molding box, pressure and vibration are applied to the concrete aggregates in the molding box to mold a concrete block, the molding box is then turned upside-down for curing and the concrete block is ejected from a lower portion of the inverted molding box.

Abstract: This invention is a chemical applicator apparatus normally secured to an auger conveyor to discharge a controlled amount of chemical or other substance to the material being conveyed into a storage bin to prevent insect damage. The chemical applicator apparatus includes (1) a main housing means to hold the chemical or other substance therein; (2) a main drive means secured to the main housing means; and (3) an actuator and discharge means connected to and operated by the main drive means. The actuator and discharge means includes (1) an actuator assembly to agitate and compact a portion of the chemical or other substance contained therein; (2) a sprocket and chain assembly driven by the main drive means adapted to receive and convey the compacted portion of the chemical or other substance to a discharge area for positive injection into the auger or other type conveyor.

Abstract: Annular magnets, primarily for motor stators, are centrifugally cast from particulate materials and synthetic plastic materials. Iron particles and ferrite particles stratified during the spin casting procedures so that the former provide an outer stratum that serves as a yoke in the permanently magnetized structure. The anisotropic ferrite particles are magnetically oriented during casting by a rotating center magnet with the aid of bucking magnets that also rotate and serve to confine the field of the center magnet to the cavity area. Apparatus for carrying out the process is disclosed and includes means for introducing the plastic and particulate materials to the mold cavity while the mold is rotating as well as mold arrangements that facilitate material introduction by the creation of reduced pressure conditions in the cavity during the rotation of the mold.

Abstract: A rotational molding system is disclosed in which a pair of large boat molds carried on separate carriages are alternately heated in a double open-ended oven having opposing cantilevered side sections for receiving concentric drive arrangements wherein the molds may be driven about two perpendicular axes in a rocking or full rotational motion.

Abstract: A method of making a prestressed concrete pole, including placing a heat softenable plastic pipe in a metal tube or pipe and filling the space between the pipes with concrete, rotating the metal pipe-concrete assembly rapidly to center the plastic pipe therein, applying hot fluid pressure to the interior of the plastic pipe, longitudinally prestressing the concrete pipe assembly for several hours while the concrete sets, and gradually releasing the fluid pressure and prestressing pressure to obtain a prestressed concrete pole.

Abstract: Disclosed is apparatus for roto-molding, multi-layered plastic containers and the like.

Abstract: A positioning apparatus for a centrifugal casting machine having an articulated mold that is mounted for rotation in a cantilevered manner on a drive shaft. The positioning apparatus includes a pair of pillow block bearings having arcuate bearing races that operate to allow the drive shaft to be tilted within a predetermined angular range relative to its longitudinal axis. In addition, the positioning apparatus includes a plurality of locking pins each of which are mounted to cooperate respectively with one of a plurality of positioning members mounted on a rotatable mold-supporting face plate of the casting machine. Operation of the lock pins into engagement with the positioning members moves the face plate into a predetermined position relative to its axis of rotation, following a casting cycle of the machine, so that segments of the centrifugal mold can be radially stripped from an article cast therein without unduly distorting the cast article.

Abstract: A centrifugal casting machine of the broken arm type has a rotatable casting arm on which a swing arm, which supports a crucible and a casting ring, is pivotably mounted. The crucible is tiltable so that upon initial rotation of the casting arm the crucible tilts to a pouring position to pour molten metal into the casting ring. A cam follower on the swing arm engages a cam on the base of the machine to hold the swing arm, during a start up period of rotation, in an orientation in which the flow path of molten metal lies in a plane approximately tangential to a circle concentric with the axis of rotation of the casting arm. This orientation and the tilting action eliminates splashing or other metal losses.After the initial period of rotation during which the metal enters the casting ring, the cam releases the swing arm for alignment with the casting arm so that the action of centrifugal force in filling the mold cavity is maximized.

Abstract: Centrifugal casting apparatus comprising a rotatable sleeve supported at a fixed axial location and having a conically tapered internal surface, and a driving sleeve axially spaced with respect to the rotatable sleeve and having a conically tapered internal surface opposed to the internal surface of the rotatable sleeve. The driving sleeve is driven in rotation and it is axially displaced with respect to the rotatable sleeve. A split mold assembly is disposed between the rotatable sleeve and the driving sleeve and includes a casing and a plurality of mold segments slidably supported by the casing. The mold segments are radially moveable towards and away from the axis of rotation between a closed mold position and a opened mold position. The mold segments can be locked in the open and closed positions.

Abstract: An apparatus and process is disclosed for rotational molding. Rotational molding is a technique for the fabrication of parts from powdered thermoplastic material in which the thermoplastic material is placed within a hollow mold and the mold is rotated in a heated environment until the thermoplastic material fuses and coats the entire interior surface of the mold. Included in the apparatus is a holding mechanism for the mold and a power mechanism to provide the required rotational motion to the mold. The power mechanism provides for simultaneous rotation of the mold about two orthogonal axes and is displaced spatially from the holding mechanism. The holding mechanism is attached to a translating mechanism which positions the molds both internal to and external to a heating chamber such as an oven while keeping the drive mechanism external of the oven at all times.

Abstract: Method for making a doll's head, for use in conjunction with a suitable torso, which will excrete a fluid through the brow portion of the head for simulating perspiration, and a method for making the same. The doll head includes an exterior surface formed and contoured with human characteristics and including an interior cavity or reservoir for storing fluid. The head is formed of flexible plastic having a slit at the mouth providing a valve for filling the interior reservoir and a plurality of small measured holes or pores in the brow or forehead which permit the fluid to flow outwardly therethrough. The method includes the steps of heating a mold containing heat curable plastic and slush molding the plastic to attain the interior shape of the mold.

Abstract: An applicator nozzle for applying a coating solution onto the molding surface of a metal mold for use in centrifugal casting. The applicator nozzle mounted on an applicator lance is provided, at its one end facing the molding surface, with a plurality of small nozzle openings which are arranged at a predetermined pitch to each other in the direction of movement of the lance into the metal mold, through which nozzle openings, a solution of coating material is emitted in solid rod-like form in such an amount as to be sufficient to complete mold coating in one way of the nozzle into the metal mold, thus producing mold coating free from an undesirable spiral pattern.

Abstract: A tapered mould consisting essentially of a rigid outer frame formed of a set of radially arranged longitudinally extending guide members and a set of axially spaced encircling rings, and a gapped frustoconical tubular casing of resilient sheet material having a set of longitudinal stiffening members arranged thereon for sliding engagement with the respective guide members. The gap in the wall of the tubular casing, extending along a longitudinal line on the periphery of the casing, is opened and closed automatically as the tubular casing inserted in the outer frame is moved axially in opposite directions. Labor - consuming bolt - clamping and releasing operation is completely eliminated and the mould operation can be mechanized with ease, as desired. Packing means interposed between a pair of stiffening members arranged on the opposite sides of the gap further ensures leak - proof gap closing.

Abstract: A mold for rotational casting of plastics is disclosed. The mold is formed in two mating sections with one section having a raised tongue and the other having a groove disposed to receive the tongue. The mold sections have flat faces fitting together in sealing engagement. A channel is formed in one of the flat faces around the tongue, and aperture means are provided to communicate the channel with the outside of the mold. Also, additional aperture means are provided to connect the groove with the outside of the mold. Thus, entrapped gases are preferentially vented to the outside of the mold rather than inwardly where they could deform cast parts.

Abstract: An apparatus for centrifugal casting in split molds has a rotatable casting head which is in the form of a hollow frustum of a cone. The head is provided with circumferentially spaced slots which extend along the generatrices of the cone. Each of the slots slidably receives a section of a mold, the various sections being so designed as to define a mold with one another when the sections are properly positioned relative to one another. Each of the mold sections is connected with, but is rotatable relative to, a hollow, primary piston which draws the mold sections together and moves them apart. A jaw chuck having a pair of jaws pivotally mounted thereon is arranged for rotation with the mold sections. The jaws are activated by a rod connected with a secondary piston which reciprocates inside the hollow, primary piston and may be moved independently thereof or in unison therewith. The rod is rotatable relative to the secondary piston.

Abstract: A device and method for use in the art or craft of molding hollow artistic objects from thermoplastic molding material, such as wax. The molding device includes a frame with a vertical stationary, circular gear rack secured thereto. A crank driven shaft is journaled through the frame in a position concentric with the rack. A yoke-like mold carrier is secured to the end of the shaft for rotation therewith. A mold holder is, in turn, mounted on the mold carrier for rotation about an axis generally perpendicular to the crank shaft axis between the yoke arms of the mold carrier. The mold holder has a shaft projecting through one of the yoke arms of the mold carrier and is secured to and driven with a disc gear, which is enmeshed with the gear rack. As the crank is turned to rotate the mold carrier, the disc gear rides on the gear rack and rotates the mold holder.

Abstract: Closed hollow toroidal articles such as hollow tires, which may be caused to be thickest at the tread, are molded on the inner surface of a closed toroidal mold slowly rotating on a horizontal axis by charging a fluid elastomer material in such quantity as to fill the bottom of the mold to a level above the wheel-supporting part of the tire and continuing rotation while causing the material to set to a solid elastomer progressively inwards from the liquid contacting surface of the mold. The relative thickness of different parts can be adjusted by changes in rotation, or by inducing different rates of setting in different parts of the mold.

Abstract: A rotatable carriage for supporting split-type plaster molds for molding ceramic hollowware is disclosed, in which the molds are retained between two frames rotatable to a succession of positions in which the molds are retained in place between the framework of one of said frames and a dual cell inflatable member on the inner face of the other of said frames. The first of said frames includes a retaining member engaging the outer surface of said mold to prevent said mold from slipping relative to said frames. A new casting method is disclosed in which the slip is poured from the filled molds in at least two steps with the rotatable frames being rotated to a different position for each of said pouring steps.

Abstract: An apparatus is provided for molding composite articles by first rotationally molding a shell-like body with a reinforcing member or frame extending through the body and supported by the walls of a mold. The hollow shell is formed of a liquid or powdered resin or other suitable material disposed in the mold per se or containing reinforcing elements which become encapsulated within the molding material. A second molding material may be injected into the hollow shell to partly or completely fill the volume interior thereof. The second material may comprise a resin containing a blowing agent which causes the resin to expand and form a cellular mass filling the hollow body or forming a shell thereagainst as the mold is rotated. The filler material may be introduced through one or more of the reinforcing members disposed within or across the mold cavity.

Abstract: An arrangement for automatically filling cylindrical containers with a liquid mixture of a powdered material mainly consisting of a starch-containing powder, thickening agents and binders with a liquid in such a way that no separation of water will take place during the stiffening of said mixture into a dough-like material. According to the invention this is obtained by rotating said container during the filling thereof with a speed within the range of 1-15 revolutions per minute, and if necessary altering the quantities of powdered material and/or liquid of said mixture.

Abstract: A molding apparatus which is provided with a frame including a bar acting as a mold support. The bar is pivoted between two angular limits and carries a gear wheel to be pivoted therewith. Planetary gears are engaged with the gear wheel and are displaced pivotally around the gear wheel to be rotated by the same. Molds are coupled to the planetary gears to be rotated therewith. Heating devices are located below the molds to heat the molds as they are being rotated simultaneously about their axes and about the axis of the gear wheel.

Abstract: A machine and method are disclosed whereby multiple casting units simultaneously produce foamed-plastic tubular articles which may be of different shapes and sizes. All units are served from a single supply of foamable material, and in each unit rotation of an annular mold develops a homogenous longitudinal and radial distribution of foaming plastic. The foaming plastic is introduced into each mold rotation, the cavity being closed to permit foamed filling of the mold, and a polymerizing cure is effected prior to mold opening and product removal. The particular machine herein described includes provision for coordinated shot size for foamable material into each of the plural mold cavities, whereby regardless of the mold-cavity size at particular casting units, the shot size (of foamable plastic material) is automatically determined, for uniform or predetermined density in the ultimate products regardless of size variation produced at the respective casting units.

Abstract: The casing is stationary and has at least one end a transverse end wall which defines an opening affording access to the end of the casting mould. A screen axially projects from the transverse end wall and extends at least partly around the opening for the purpose of screening the machine operators off from any splashes of molten metal which might be thrown out of the mould due to a faulty socket core.

Abstract: In a centrifugal casting machine, the mould carries a ring having a groove defining two spaced-apart annular non-axially extending bearing surfaces. The fixed frame of the machine carries a fixed journal perpendicular to the axis of rotation of the mould and contained in the plane containing the axis of rotation of the mould. A lever perpendicular to the journal is pivotably mounted on the journal and carries two support rollers freely rotatable on the lever. The axes of the journal and the support rollers are in the same plane and parallel to each other. The rollers taper to the axis of rotation of the mould and the two annular surfaces have the same taper as the rollers. The axial distance between the two annular surfaces of the ring allows the lever to pivot about the journal so that both rollers are always in contact with one of the annular bearing surfaces.

Abstract: This invention relates to an apparatus for transferring a mold from a centrifugal compacting device to the next place in the process of manufacturing a concrete pole or pile, by using many jacks to raise a mold from on the centrifugal compacting device for the transferring operation to rails on which the mold is put to be transferred to the next place.

Abstract: Labor-consuming bolting operation as required with conventional forms of the gapped or split type has been ingeniously expelled by the provision of a form structure comprised essentially of a rigid tubular frame, a resilient gapped tubular casing arranged therein as a form in which concrete is to be placed, and camming means arranged on the inside of the rigid frame and on the outside of the resilient casing and cooperable to act upon the resilient tubular casing radially and circumferentially thereof with axial movement of such resilient casing relative to the rigid frame so as to close the gap in the resilient casing while holding the latter in coaxial relation to the rigid frame, any loss of moisture content of concrete during centrifugal forming operation can be effectively prevented by arranging an appropriate packing element on the resilient casing along the gap therein.

Abstract: A device for removal of a moulded product from a rotational moulding machine with one or a plurality of two-part moulds. The mould or moulds are movable between a closed and an open position on rotative supports in the machine frame. The removal means comprises a pair of complementary grasping elements operative to straddle each mould on either side of the mould opening zone and which can be moved towards each other at the moment when opening of the mould commences to grasp and hold the moulded product therein prior to further opening movement of the mould and to release the product therefrom. The grasping element support is operable to move from the position straddling the mould and to a position outside the machine for discharge of a moulded product, and vice versa.

Abstract: Reinforced plastic pipe and similar tubular members are formed by centrifugally casting filamentary strand materials, such as glass roving, in a rotating cylindrical mold. A solvent dispersed mold release agent may be sprayed into the mold prior to the application of the filament. Thereafter, a spray of catalyzed binder resin is added to the filamentary material. A lance is extended into the mold and contains feeding tubes for depositing the filamentary strand, as well as nozzles for depositing the resin on the surface of the mold. Also, the lance contains extra nozzles for the addition of particulate matter such as sand to achieve desired structural quality and economic fabrication of the tubular member. The amount of the components added and the timing of the component addition is determined by the desired end product to be achieved.

Abstract: An apparatus and method for making seamless tubular containers having a first end terminating in a shoulder and threaded neck of a reduced diameter with increased wall thickness and a second open end. The process uses a mold having an internal surface configuration corresponding to the external configuration of the desired tubular container. Suction means draws electrostatically charged powder through the mold and permits a portion thereof to deposit on the internal surface, the amount of deposition being partially controlled by the surface configuration. Subsequently, the container is heated to fuse the deposited powder into homogeneous mass, while subsequent cooling permits shrinking of the container away from the mold walls such that it may be removed by hand or by mechanical apparatus.

Abstract: A pipe of concrete, cement mortar or other cementitious material is formed by an integrally cast cementitious mass which is reinforced with a glass fibre strand or roving forming a substantially helical winding extending around the pipe and incorporated in the cement matrix of the cementitious mass. Preferably there are two windings, one incorporated in the outer periphery of the mass and the other incorporated in the inner periphery of the mass. The pipe is preferably made by a centrifugal casting operation in which a centrifugal casting mould is rotated and the glass fibre strand or roving is fed from a feeding device within the mould and is caused to adhere to the internal peripheral face of the mould and then the feeding device is moved axially along the mould as the mould rotates so that the winding is formed from the roving around the internal peripheral face of the mould.

Abstract: A rotary casting apparatus for molding hollow articles of synthetic plastic is described employing a plurality of hollow molds which are heated and rotated within a fixed oven. The molds and molded articles therein are cooled rapidly while they remain within the oven by injecting cool, moist air into such oven from an external blower fan and a sprayer which sprays water into the air inlet of such fan. Improved rotation and support means are provided for the molds, including a common tubular drive shaft which rotates all of the molds about a common axis and a plurality of rotor means for rotating each of the molds about another axis perpendicular to such common axis. The rotor means are coupled by bevel gears to a second drive shaft extending through the common drive shaft. Each of the molds is rotationally mounted on bearings which are supported on the common drive shaft.