Abstract: A driving device (14) of an acoustic vibration plate (11) is arranged between a speaker frame (10) and the acoustic vibration plate (11). The driving device (14) is comprised of a pair of piezoelectric vibration plates (1, 2) arranged facing each other across a certain distance. The outer peripheries of the piezoelectric vibration plates (1, 2) are connected to each other by an annular spacer (7). When a drive signal is applied to the piezoelectric vibration plates (1, 2), the piezoelectric vibration plates (1, 2) repeatedly undergo flexing motion wherein their centers flex alternately in opposite directions. At this time, the flexing directions of the piezoelectric vibration plates (1, 2) are always reverse to each other.

Abstract: A system of injection-molding a super-precision product by an injection machine with a mold comprises conventional fundamental steps including a material plasticizing and metering step, an injection step and a material pressure-holding step, with additional features in that a nozzle passage, enlarged in volume, extending from a machine body to a cavity gate is interrupted midway therealong by a valve from communication with the interior of the body, after the injection step but while the pressure-holding step is being carried out. The pressure-holding step is carried out at least using the valve for exerting an internal pressure on a forward portion of the injected material separated due to the passage interruption, and compacted in a fixed closed space limited by the valve including a mold cavity, during which step a next plasticizing and metering step is commenced.

Abstract: A process and apparatus for injection molding of plastic material incorporate a perforated member for melt filtering and/or melt mixing during metering of plasticized material. The perforated member may be of a disk form mounted to a screw plunger provided within a machine body with the perforations arranged around the screw plunger. Impurities accumulated at the perforated member may be purged by rotating the screw plunger from a nozzle connected to the machine body via an annular recess formed at an inner surface of the machine body or directly from the machine body per se via a radial hole formed therein, when the screw plunger is in a predetermined position preferably in the most forward position, where the recess or the hole is located in the vicinity of the perforated member.

Abstract: A system of injection molding by an injection machine with a mold includes conventional fundamental steps including a material plasticizing and metering step, a material injecting step and a material pressure-holding step, but with an additional feature in that nozzle passage is interrupted midway therealong from communication between the interior of a machine body and a mold cavity, after the injecting step but while the material pressure-holding step is being carried out. The material pressure-holding step is carried out first using the injection machine per se operated with a plunger to exert a first non-stepped external or internal pressure on the entire injected material but second using another mechanism for exerting a second non-stepped or stepped internal pressure on a forward portion of the injected material separated due to the nozzle passage interruption.

Abstract: A method and an apparatus for injecting a steam into a mold in an injection molding machine by injecting a desired stream toward the opening of the metal mold including a gate and cavities in connection with the opening and closing operation of the metal mold thereby intending the cooling solidification of the molten resin on th gate portion and simultaneously intending removal of dewing and an oily matter on the surface of the metal mold.

Abstract: In a temperature control indicating apparatus of a hot runner in a thermoplastic synthetic resin injection molding system, the apparatus has a hot runner comprising a body heater, a tip heater and a temperature sensor. The hot runner is connected to a hot runner temperature control circuit having A/D converter. The apparatus has the function of arithmetic control, setting operation and display. Further, the apparatus comprises a digital control means including a microprocessor, thereby the body heater of the hot runner is digital-controlled in the process of thermoplastic synthetic resin injection molding operation.

Abstract: A runnerless method for injecting and molding a synthetic resin through a gate wherein a molten resin is intermittently cooled to solidification using a cooling medium to close the door for every injecting and molding operation of a molten resin in the gate, and relates also to a novel runnerless apparatus for injecting and molding a synthetic resin provided with a metal mold mechanism composed of a plural number of component members, in which the passage for the molten resin including a runner, the gate, and a cavity are drilled, a cooling medium-employing intermittent cooling mechanism for intermittently cooling the gate thereby enabling solidification of the molten resin in the gate, a mechanism for continuously applying heat to the gate for melting an existing resin, and an injection mechanism.

Abstract: A pointed heat-generating device includes a fine and small heat-generating coil which gradually changes its winding diameters or winding density. The pointed heat-generating device is fixed to a heat-generating front part of a projectile-shaped heat-generator main body. The thermal distance between the heat-generating coil in the pointed heat-generating device and the tapered peripheral surface of the heat-generating front part is shortened and maintained constant over its the whole area.

Abstract: In a small-sized and precision injection molding apparatus, a raw material supply means, a raw material plasticization means, an injection plunger means and a melted resin flow passage means are all together incorporated in a mold, thereby a substantial distance from the raw material up to a cavity becomes shorter. Thus, an overall construction of the injection molding apparatus becomes small-size and compact.

Abstract: A heater is incorporated in a pointed conical heat-generating means fixed with a projectile heat-generating body. The heater is a ceramic columnar body having a heat resisting and insulating property. Disposed within the ceramic columnar body is a coiled heating wire of which winding diameter is formed as small as possible. Due to discontinuous energizing process of the heater, thermoplastic synthetic resin adjacent a gate can be heated and fused, or cooled and solidified intermittently, thereby the gate communicated with a cavity can be opened or closed effectively.

Abstract: This invention relates to an injection molding process for synthetic resin and its apparatus which enables the production of highly precise molded articles and a shortening of the molding time. More particularly, by actuating a forcible cooling means mounted in a mold part constituting a gate, the synthetic resin fused by local heating of the gate is cooled and solidified forcibly, thereby closing the gate. On the other hand, by stopping the forcible cooling means, the solidified resin in the gate is heated and fused by a heater mounted either inwardly of a runner or outwardly thereof.

Abstract: This invention relates to hot tip bushing means for a synthetic resin injection molding machine, which can reduce the pressure loss at the injection molding time and determine the position of a heating tip easily and accurately. To attain this purpose, a straight resin flow passage is formed axially in a cylindrical body of the hot tip bushing means and the fused resin passing through the straight resin flow passage is heated by an outer heater. Further, a cylindrical body of the hot tip bushing means which is near the heating tip is fit to a mold sprue, thereby the position of the heating tip is determined easily and accurately.

Abstract: This invention relates to an injection molding process for synthetic resin and its apparatus which enable to produce highly precise molded articles and shorten the molding time. More particularly, by actuating a forcible cooling means disposed in a runner and extended into a gate, the fused resin in the gate is cooled and solidified locally, thereby the gate is closed. On the other hand, by stopping the forcible cooling means, the solidified resin in the gate is heated and fused by a heater mounted either inwardly of a runner or outwardly thereof.

Abstract: The present invention relates to a novel toggle means which is used for the mold locking and opening of injection molding machine or for the like.

Abstract: The present invention relates to a mold opening and locking mechanism in an injection molding machine or the like.

Abstract: A process for producing dodecanedioic acid dimethyl ester comprising the steps of reacting cyclohexanone with methanol and hydrogen peroxide in the presence of an acid catalyst and water at a temperature below the boiling point of the methanol to produce methoxycyclohexyl peroxide, said methanol and hydrogen peroxide being used in an amount of about 15 to about 36 moles and in an amount of about 0.5 to about 1.5 moles per mole of the cyclohexanone respectively, dimerizing the resulting methoxycyclohexyl peroxide as it is contained in the reaction mixture in the presence of a ferrous salt and at least about 25 moles of methanol per mole of the starting cyclohexanone to produce dodecanedioic acid dimethyl ester, and separating the resulting dodecanedioic acid dimethyl ester from the reaction mixture.