Abstract: A method and apparatus for heat forming hardboard and other types of forming board including the steps of placing a mesh screen in a die between upper and lower platens having mating contours, placing a sheet of heat formable board in the die upon the screen and below the upper platen, pressing the platens together and heating the sheet such that the sheet and screen are formed to the mating contours and gases and vapors released from the sheet follow the contours of the screen to escape from the die, separating the platens, and removing the sheet from the die.

Abstract: A method of manufacturing brushes wherein two brush tapes which are formed of synthetic resinous material and incorporate a plurality of bristle filaments held together by a knitting operation or a weaving operation or by means of an extruded bead are arranged adjacent each other and held in this relationship by means of a bead of synthetic resinous material running along one side edge of the tapes. This bead may be extruded around the adjacent edges of the tapes or if beads of plastics material are already present on the tapes, may be formed by fusing the two beads together. There may be more than two adjacent tapes which may be arranged side-by-side or at an angle to each other or spaced apart and the construction of the tapes can be the same or different. Furthermore, one or more barrier layers may be located between the tapes. It is even envisaged that un-beaded tapes could be fused together, and the bead would then be formed by a forming operation.

Abstract: A method for preparing solid metallurgical mounts uses a surface in heat exchange relationship with mounting molds placed thereon and with an initially liquid mounting agent contained in the molds. The surface is defined by a block of polytetrafluoroethylene exposed to a source of heat. As part of the molding operation, the surface is preheated and maintained at a substantially constant temperature throughout the operation. The molding operation includes mixing of a quantity of epoxy resin and a hardener, pouring the mixture into a mold or molds and curing the mixture at an elevated temperature in contact with the polytetrafluoroethylene surface.

Abstract: A safety blade for a powered rotary lawn mower and method of making same. A layer of high strength fabric of an organic polymer extends throughout the blade. A metallic bar is positioned primarily in the central portion of the blade. The fabric and bar are bonded together and encapsulated in a elastomeric material containing fibers of an organic polymer. The blade is formed so that the outer end portions are provided with cutting edges with the fabric intersecting the cutting edges.

Abstract: The invention disclosed is an apparatus for making a thermoplastic film embossed with tapered bosses having perforations in the tips of each boss through use of a metallic pattern roll and a heated perforating roll. The apparatus and method allow a film having tapered bosses with decreased cross-sectional areas leading to a perforation to be formed without use of expensive vacuum forming methods.The invention discloses a film 10 being heated by a heating means 14 to a deformable state and being embossed on an embossing surface 16 of embossing roll 13 under pressure from the silicone rubber surface 33 of first pressure roll 15. The flm on the apex, 262 of the cone 26 on embossing surface 16 is removed to perforate the cone by perforating roll 17, which is a resilient hollow metal tube heated from a radiant heater mounted on the inside of the hollow metal tube. The perforated film is then embossed a second time by the action of a second embossing roll 18 and then rewound onto a rewind roll.

Abstract: A method of annealing a PTC conductive polymer composition comprising a mixture of two crystalline polymers. Compositions having improved electrical characteristics are obtained by annealing at a temperature between the melting points of the two polymers, preferably closer to the melting point of the lower melting polymer. Particularly useful results are obtained when the annealing method is applied to a self-limiting heater in which the PTC core comprises carbon black dispersed in a mixture of polymers, one of which has a melting point of at least 160.degree. C., preferably at least 200.degree. C., e.g. a mixture of polyvinylidene fluoride and an ethylene/tetrafluoroethylene copolymer.

Abstract: In the manufacture of eyeglass bows, a metal core (2) is placed in a mold (1) and is gripped at one end (3) before the mold (1) is filled with plastic material.To ensure that the metal core (2) can be held in position in the mold (1) as the plastic charge enters, the metal core (2) at that end thereof which is opposite to its gripped end (3) is joined to a tensile element (6), which extends out of the mold. The joint between the tensile element (6) and the metal core (2) forms a rated breaking point having a limited ultimate tensile strength. Before the mold (1) has been completely filled with plastic charge, a tensile stress in excess of the ultimate tensile strength of the joint is applied to the latter by the tensile element (6) so that the tensile element will be severed and pulled out of the mold (1).

Abstract: The invention provides for a process for constructing manhole assemblies in an excavation or elsewhere, by the utilization of an outer form, a preformed manhole barrel which is positioned and propped within the outer form pipe stub inserted partially into the inside of the preformed manhole and resting under notches cut into the preformed manhole barrel, inflatable or rigid forms (or both) are used to form simple or complex channels in the concrete which is to be poured. The form ends are adapted to fit into the pipe stub ends or may abut other forms, where complex channels are desired. The forms are carefully positioned to allow for the proper height and grade of the channel in the completed manhole assembly. Concrete is poured and when it is set, the forms are deflated where applicable and removed to be reused.

Abstract: A process for the manufacture of thermoplastic sheet having elliptical perforations including a rotatable molding element having a series of hexagonal-shaped depressions having centered therein elliptical holes, the elliptical holes having a major axis and a minor axis, the major axis being oriented parallel to the direction in which the molding element is rotated, a means for applying a fluid pressure differential to a surface of the thermoplastic sheet to force the sheet against the molding element to effect rupturing of the sheet and the formation of elliptical holes in the sheet.

Abstract: A vibratory concrete screed includes a generally triangular, open support frame to which front and rear screed blades are coupled. Air vibrators are coupled at intervals along the front and rear screed blades to impart vibratory motion to the blades. First and second end brackets are coupled to the screed top pipe and to the front and rear screed blades and include first and second side members which define a plane oriented perpendicular to the front and rear screed blades. A vertically and horizontally adjustable extension bracket is coupled to the first and second side members of the end bracket of the screed and is maintained in a plane perpendicular to the plane defined by the first and second side members of the end bracket.

Abstract: A process for applying a cover layer based on thermosetting resin to objects of thermosetting resin.The process is characterized in that a shape imparting support face is heated to a temperature of 90.degree.-200.degree. C. and then is provided with a cover layer of a thermosetting resin with catalyst. After hardening the cover layer and cooling below 90.degree. C. a basic layer thermosetting resin is applied and hardened.

Abstract: The invention concerns a process in which a shaped article is prepared by first coating the inside of a mold with a coating powder, curing the coating, introducing a thermosetting mass in the mold and curing to form an article provided with a decorative layer. The invention consists in the use of a polyester-based coating powder, obtained by absorbing a liquid catalyst in part of the unsaturated components making up the powder, separately grinding that part and a mixture of the remaining components to about the same particle size and mixing the powders thus obtained. The invention assures better curing of the coating.

Abstract: A method of insulating electrical connectors having terminals with leads extending therefrom by using a flexible insert arrangement for an electrical connector mold for supporting leads extending therefrom and closing the mold end which includes a flat resilient body having one or more lead-accepting depressions normal to the body across one edge thereof and an arrangement actuable as the mold halves are closed on one another for deforming the body to temporarily displace the body resilient material about each electrical lead extending from the mold to complete the formation of an insulating material-accepting connector forming cavity. A flowable insulating material is then injected into the cavity to form the insulated connector.

Abstract: A method of forming, in two steps, panel, or shaped article, by first providing a bath of fluent cementitious material under a core of cellular, preexpanded and cohered polystyrene cells or pearls, having a density less than that of the cementitious material, allowing the core partially immersed to rise in a controlled way over the cementitious material, maintaining the core under pressure until the bath has partially set to prevent further rise of the core, pouring onto the core and partially set bath, a second quantity of fluent cementitious material to completely enrobe the core and form thereover a top revetment, smoothing the surface of the second quantity of cementitious material and letting it set to complete the panel.

Abstract: A process for manufacturing a closure cap having a liner. A mass of molten thermoplastic is positioned in the inner face of a cap shell. The mass is spread by a heated punch and the spread mass is then formed by a cooled punch to the final liner shape.

Abstract: A method and mould for moulding material requiring heat treatment for setting or curing, e.g., for making ophthalmic lenses. The mould comprises an annular gasket and two opposed die members which together define a moulding cavity. One of the die members is made in part of a fusible material, e.g. paraffin wax, which defines its moulding surface. After filling the mould the moulding material is subjected to heat treatment. The drop point or softening point of the fusible material falls within the range of temperatures of heat treatment so that in the course of such heat treatment of fusible material effectively releases the moulded material. This relieves stresses which would otherwise develop due to shrinking of the moulded material.

Abstract: An improved method and apparatus for efficiently and at an improved rate cutting an extruded clay column, strand or strip, or a portion thereof, into individual brick mouldings. A conveyor brings the uncut strip portion into a predetermined position beneath a cutting device and by causing relative vertical movement between the conveyor and a lifting table the uncut portion is transferred to the lifting table, itself comprised of a plurality of separate supports spaced apart both transversely of and in the direction of travel defined by the conveyor. While supported by the lifting table, the clay strip is cut by a plurality of cutting wires secured under tension in a frame which is lowered with respect to the table so that the wires pass through the clay. Thereafter the frame is raised to its starting position and the cut mouldings redeposited on the conveyor by again causing relative vertical movement between the conveyor and table.

Abstract: Reinforcing fibers of plastic having a surface tension of from 40 dyn/cm to about the surface tension of water are disclosed. The fibers can be easily and uniformly disposed in matrices. For organic matrices, a surface tension of 40-50 dyn/cm is effective. For cement matrices, a surface tension about 70-75 dyn/cm is effective. The high surface tensions are obtained by a corona treatment and subsequent application of a hydrophilic avivage. Corona treatment may be performed on the fibers, or on films from which the fibers are made.

Abstract: The flatness of compression-rolled plastic film is improved by passing the film under tension over heated rolls, stretching the heated film, setting the stretched film by passing it over a tempering roll, and then cooling the set film by passing it over a cooling roll.

Abstract: A device for uniform pinning of molten web material onto a quench roll by means of at least two vacuum zones interacting through a baffle, one vacuum zone extending past the line of contact of the web on the quench roll to encompass a portion of the web edge laid onto the casting drum.