| 摘要 |
828,083. Extrusion and injection moulding machines. BEANWY ELECTRIC Ltd. Dec. 19, 1957 [Sept. 20, 1956], No. 28727/56. Class 87(2). [Also in Group XI] A barrel or cylinder 1 of steel or other magnetisable metal forms part of an extrusion or injection moulding machine and is heated by an induction unit consisting of a U-section magnetisable metal casing 4 which is fitted on the cylinder and which contains a multi-turn coil 8 arranged so as to provide an annular duct 9. Cooling fluid, e.g., air from a compressor, is fed into the duct via a passage 11 and is discharged through an opening 12 ; a heat resisting sleeve 10 lines the coil, which is controlled by a thermocouple or equivalent device. The air supply may be controlled by a valve operated manually or by a thermostat, and may be fed to a number of heating units of which the cooling ducts are connected in series. Alternatively a number of units may be fed from a manifold pipe provided with branch pipes, control being by a single valve or a valve in each branch pipe. Annular cooling manifolds may be provided on the side walls of the casing 4, and flutes or splines for additional cooling effect may be formed in the cylinder 1, Fig. 2 (not shown). In another modification, circumferential grooves may be formed in the cylinder periphery, Fig. 3 (not shown). In a further construction the casing is of double U section to provide two channels each containing current conducting coil and a lining sleeve separated from the cylinder by an annular duct. Preferably the thermosensitive devices for controlling the cooling fluid valves and the coil circuits operate so that the coils are de-energised when the fluid is flowing through the units, and are energized when the flow of fluid is interrupted. Each thermosensitive device may operate a temperature indicator to enable an operator to ascertain when to open or close any valve or coil circuit. |
