Abstract: A nozzle for injecting molten plastic includes a housing having an inlet and an outlet. Wires embedded in the housing serve to heat the housing. The housing defines a chamber, and a strainer is disposed in the chamber between first and second guides which are respectively located adjacent to the inlet and the outlet. The strainer and the guides divide the chamber into an outer compartment which surrounds the strainer and an inner compartment within the strainer. A rod extends through the inner compartment and carries first and second pistons which are slidably supported by the first and second guides, respectively, so that the rod can be moved between two terminal positions. Each of the pistons is provided with an axial blind bore and several radial bores which radiate from the associated blind bore.

Abstract: A device for heating components of tools and machines has another ring and an annular or tubular part which is surrounded by the outer ring. The annular or tubular part has a heatable surface and may constitute a tool or machine component or, alternatively, may be designed to be slipped onto such a component. The outer ring and the annular or tubular part cooperate to define a space and an electrical resistance heating element is received in this space with no play. The outer ring and the annular or tubular part have one or more pairs of abutting surfaces and the abutting surfaces of each pair are joined at their outer margins by a continuous weld seam. The weld seam or seams join the outer ring and the annular or tubular part to one another and provide gastight and liquidtight seals between the space containing the heating element and the atmosphere. The outer ring has a coefficient of thermal expansion less than or equal to that of the annular or tubular part.

Abstract: An electrically operated heating element for a hot-runner tool has a heat conductor and is positioned in a hot runner and in runners that derive from the heat conductor and lead to a series of outflow channels 8 from the hot-runner tool. The heat conductor is a flat body with tongues on the side toward the outflow apertures, each tongue extending to the vicinity of one outflow aperture.

Abstract: The injection nozzle has a central heating rod (1) and jacket components (2 and 3), with the heating rod connected at the upper end with one (3) of the jacket components and at the lower end, through a fork (8), with the other (2). The jacket components are electrically insulated from each other by disks (4 and 5) and demarcate an annular channel (15) for the plastic to flow through. The plastic is introduced into the channel at the top and through exits (14) at the bottom into the supply aperture of an injection mold. The nozzle has two points (11) at the bottom, each extending into or into the vicinity of one supply aperture to a mold cavity. Two mold cavities can accordingly be simultaneously filled with plastic by one injection nozzle.

Abstract: An electrically operated heating element for a hot-runner tool has a heat conductor and is positioned in a hot runner and in runners that derive from the heat conductor and lead to a series of outflow channels from the hot-runner tool. The heat conductor is a flat body with tongues on the side toward the outflow apertures, each tongue extending to the vicinity of one outflow aperture.

Abstract: A hot-runner tool with at least one hot-runner section for supplying molten plastic to an injection mold, preferably a multiple injection mold with a pin-point gate for each casting. The hot-runner section has an outer housing with a flow channel, at least one inlet, and at least one outlet and a heat conductor that can be connected to an electric voltage and that the molten plastic flows around. The flow channel in the hot-runner section is demarcated externally by at least one metal tube that is separated from the heat conductor and a layer of heat insulation is positioned between the metal tube and the inner surface of the outer housing. The metal tube can store and conduct a lot of heat and helps to heat up the plastic rapidly. Since the tube supplies additional heat to those points along the hot-runner section where the plastic needs more heat than at other points, the tube homogenizes the molten plastic along the total length of the hot-runner section.

Abstract: An arrangement for supplying molten plastic material in heated condition to an injection mold has a plurality of heating passage forming elements which are formed as separate units capable of being mechanically assembled with one another, and each provided with a housing having at least one inlet and one outlet opening, and with an electrical heating member which is electrically controlled independently of the heating members of other heating passage forming elements.