Abstract: An injection nozzle for use in an injection molding apparatus including a generally annular base portion which supports a generally cylindrical hollow side wall portion. The hollow side wall portion terminates at its upper end portion in an inwardly beveled heat transfer control portion. The beveled heat transfer control portion terminates in an angled mating portion which is of complementary angle to the angled mating surface of an injection nozzle accepting recess in the injection mold portion of the apparatus. The injection nozzle structure provides for controlled heat transfer control from the sprue portion of an injection molded parison to prevent crystallization in the sprue portion of the parison.

Abstract: In an injection mold apparatus for manufacturing molded bodies from two types of plastic, a first and third injection units (4 and 6) are connected to a single mold cavity, and a core piece (15) which is movable back and forth occupies a region of the mold cavity when said core is in the blocking position, and said core in this position separates (by closing off) a first mold cavity region (associated with the first injection unit) and the entrance opening of material coming from the third injection unit (6) into the mold cavity from a second mold cavity region (which is connected to the first injection unit (4), whereby first the second mold cavity region is filled from the first injection unit and then, after the core (15) is drawn back, the region of the mold cavity initially occupied by said core, and the first mold cavity region, are filled from the third injection unit, and whereby the core has a recess, the improvement comprising providing the recess (37) in the blocking region of the core (15), whereb

Abstract: A universal injection molding system has plural pairs of mold inserts that are engageable for mold cavities mounted on mold bases, respectively, on the relatively movable top clamp plate and base support plate of an injection molding machine. Rails on those bases hold the mold inserts in place in paired alignment. With the plates and bases closed to bring together respective mold insert pairs, the mold inserts are securely clamped in relatively fixed positions on the plates and bases. A multiple stage ejecting/stripping apparatus also is provided to strip parts from mold cavities, and a technique is provided to eject the sprue before the parts. Methods of facilitating set-up of an injection molding system and of injection molding also are disclosed.

Abstract: A folding apparatus and method for folding a flat sheet so that an exact interior height is provided between the two folded portions is disclosed. The flat sheet is folded about a shim having a folding edge which is rounded and which has a thickness corresponding to the desired interior height. The flat shim is positioned on the flat sheet with the edge of the shim located along the line where the fold in the sheet is to be made. Initially, the portion of the sheet away from the shim is folded approximately 90.degree. by tangential bending on the folding edge of the shim. Next, a die having a facing edge mating with the folding edge of the shim is pushed onto the folding edge of the shim. The portion of the sheet which was folded 90.degree. is thus folded onto the top of the shim to approximately 180.degree.. With this two step folding, an exact interior height adjacent the fold is provided.

Abstract: Apparatus including a material reservoir, a tool having a mold cavity, and a cylinder having a plunger for pushing material received by the cylinder from the reservoir into the mold cavity. Equipment is provided for evacuating the reservoir, the mold cavity, and the cylinder. The reservoir is connected to the cylinder in a vacuum-tight manner. The evacuating equipment includes a vacuum pump and a vacuum reservoir, and valves permit optional connection of the material reservoir and the mold cavity to the vacuum pump or the vacuum reservoir. The volume of the vacuum reservoir is many times, i.e., 100 to 1000 times, greater than that of the mold cavity. A shutoff valve for disconnecting the mold cavity from the evacuating equipment is located in the immediate vicinity of the mold cavity. All the valves may be operated in a predetermined sequence by a control unit. The material reservoir may serve simultaneously as the vacuum reservoir.

Abstract: This relates to an injection nozzle which is provided with a valve gate pin for selectively interrupting plastic flow therethrough. The internal construction of the nozzle is such that the plastic flowing therethrough for injection into an injection mold is uninterrupted and in no way divided so that there will be a separation of the plastic and a rejoining in a manner which will provide for a welded interface. The valve gate pin, notwithstanding the uninterrupted flow passage, is fully supported throughout its length.

Abstract: For the purpose of making a joint socket comprising at least two portions, namely a portion for receiving a plastic pipe end and another portion into which a rubber ring is fitted, a device for heating and softening a plastic pipe end and enlarging the radius of the softened pipe end to twice its size which includes, an inwardly slanted portion between a first outwardly slanted portion and a second outwardly slanted portion whose radius becomes smaller as it comes nearer to the front end thereof. As the result, the frictional resistance between an improved core and the radius enlarged softened pipe is reduced to a value which enables the device to be operated such that wall-thickened sockets can be made without loss of wall thickness subsequent to the radius enlarging process.

Abstract: A hot sprue assembly is provided for controlling flow of molten material into the mold cavity of an injection molding machine. The hot sprue assembly is particularly designed for use with an injection molding machine for molding centrally apertured record discs, such as video information discs. The hot sprue assembly includes a hot sprue bushing cooperating with a dispersion head to define an open and relatively narrow annular gate through which molten material is injected into the mold cavity, and a central die plug within the mold cavity for cooperating with the dispersion head to mold a central aperture into the disc. Valving of the molten material through the gate is achieved by heating the sprue assembly to create a temperature differential which, during solidification of the material within the mold cavity, permits the material within the mold cavity to solidify up to the gate without substantial solidification of material within the sprue assembly.

Abstract: In a machine for the continuous and automatic production of a succession of small components from synthetic plastics material by injection moulding, the mould and injection unit are operatively connected to a common actuating device through two separate transmission mechanisms which both include an element reciprocable along the longitudinal axis of the machine and are so interconnected that the injection unit cannot operate until the mould has been closed.

Abstract: A method of and an apparatus for molding a plastic wherein the injection pressure (transfer pressure) is switched to a holding pressure when the internal pressure of the mold cavity sensed by a pressure sensor reaches a predetermined injection pressure (transfer pressure), to initiate holding of the pressure applied to the cavity. The holding pressure is removed when the internal pressure thereof becomes zero or in accordance with the detection of a predetermined inflection point in the internal pressure which is indicative of a gate sealing point in the mold cavity or is brought to a predetermined value close to zero. The molded articles are of high precision finishes, and conservation of energy and natural resources can be achieved.

Abstract: An intermediate platen carrying two inner plates of a stack mold, coacting with two outer plates respectively mounted on a stationary and a movable platen of an injection-molding machine which are interconnected by a set of four tie bars, has a pair of forwardly extending and a pair of rearwardly extending outrigger arms terminating in respective shoes which slide on two of the tie bars, preferably the lower ones.

Abstract: An injection molding machine includes a molding removal mechanism including a double-acting, fluid-operated cylinder which has a chuck mounted thereon for grasping a molded part, said cylinder being rapidly operated for removing the molded part from the mold and slowly actuated for transferring the molded part to a discharge position.

Abstract: A method for manufacturing high information density storage disks, suitable for optical reading, out of transparent synthetics having a high glass temperature and high dimensional stability. The present injection molding method avoids potential double diffraction disruptive effects created by frictional or shearing forces. The synthetic material which is to be pressed is injected into one of the mold halves at a temperature that significantly exceeds the pressing temperature of the compression form and is injected so as to form a lump of the material. The pressing step wherein the compression form is closed down to a squeezing gap width is initiated prior to the termination of the injection operation. Likewise the cooling operation is initiated prior to the termination of the pressing step and both the cooling and pressing operations chronologically proceed at approximately an exponential rate.

Abstract: An injection molding machine comprises an injection piston-cylinder mechanism including therein an injection piston and a booster piston. The booster piston is provided with a longitudinal through hole through which a pressurized fluid is supplied from an external source into the piston-cylinder mechansim so as to act on the injection piston to fill the mold cavity with molten bath. When the inner pressure of the cylinder chamber between both pistons reaches a predetermined value or the injection piston reaches a predetermined position, a valve assembly which is connected to the cylinder chamber through a conduit is operated so as to drain the pressurized fluid in the cylinder chamber in a controlled manner thereby to advance the booster piston.

Abstract: A tube shaping device is described for shaping the deformed end of a flexible tube, for example, toothpaste tubes, medicine tubes, paint tubes and the like. Such shaping device is constructed from a cylindrical body having an opening at one end thereof and a conical shaping member arranged within the opening extending outwardly therefrom. The conical shaping member is adapted to increasingly be received within the open end of the tube until the shape of such tube end is conformed to the circumferential shape of the base of the shaping member.

Abstract: An apparatus is provided for rotating the terminal blade for a structure which comprises a pair of terminal blades attached to a wire cord. The apparatus comprises a support for supporting the terminal blades, the support including a recess having contact surfaces wherein the terminal blades contact the recess on the contact surfaces thereof. At least one blade rotating device is provided which has a projection extending therefrom. A drive moves the recess and the blade rotating device towards each other such that the projection is moved between the terminal blades and contacts one edge of each of the terminal blades. The opposing edges of the terminal blades contact the contact surfaces of the recess, thereby causing each terminal blade to rotate between the projection and the recess such that the pair of terminal blades are aligned and positioned in parallel planes.

Abstract: This invention relates to an improved valve pin for an injection molding system and a method of making the same. The elongated valve pin has a tip end portion which extends from a larger driven end portion into the flow of melt to the cavity. The elongated tip end portion is provided with a desired combination of strength and thermal conductivity by having a copper core inside a steel casing. The casing is made by brazing a tip end cap member to a hollow sleeve. A predetermined quantity of copper wire is then inserted into the casing and melted in a vacuum furnace to form an integral construction. The excess sleeve is then cut off and the end is brazed into a well in the driven end portion of the valve pin. The tip end cap member is then machined to provide a tip end of a desired shape.

Abstract: High density information discs, such as video discs, which have been treated with an ammonium salt become resistant to and stable under conditions of high relative humidity, even after repeated exposure to such conditions for extended periods of time. The treatment with the ammonium salt is accomplished by use of a bath of an aqueous solution of the ammonium salt, with the preferred ammonium salt being ammonium chloride.

Abstract: A hot sprue valve assembly is provided for controlling flow of molten material through a hot sprue bushing of an injection molding machine. The valve assembly is particularly designed for use with an injection molding machine for molding centrally apertured record discs, such as video information discs. The valve assembly includes a poppet valve movable between an open position to allow flow of molten disc-forming material into a mold cavity, and a closed position to prevent flow of the disc-forming material into the mold cavity. The poppet valve is designed to mold a central aperture in the disc upon movement to the closed position, and the valve assembly is designed to accommodate air ejector apparatus for removing a solidified record disc from the machine.

Abstract: Undercut tubular synthetic plastic articles, such as fittings, are formed in the mold cavity of an injection molding machine on a two-piece core a tubular component of which is surrounded by the undercut portion of the article and a first smaller-diameter portion at one side of the undercut portion. A cylindrical component of the core slidably guides the tubular component and is surrounded by a second smaller-diameter portion of the article at the other side of the undercut portion.