Abstract: A method of heating a parison neck by stretching blow molding, wherein an injection molded synthetic resin parison is adjusted in temperature while holding a parison neck, by a neck mold for molding a parison neck, after which the parison is stretched and expanded to form a container such as a bottle, the method comprising at the time of adjusting temperature of said parison, heating a lower end of the neck mold and applying heat enough to prevent formation of an annular constriction in a molded product, to a border between a parison neck covered by the neck mold through the end of said neck mold and a body.

Abstract: A molding machine disclosed herein comprises a rotary disk having the required number of openable and closeable neck molds, said rotary disk being located on the underside of a base plate, said rotary disk being capable of achieving intermittent rotation to successively transport said neck molds to an injection molding stage, a temperature control stage, a stretching blow molding stage and a molded product releasing stage for continuous operation from the injection molding of bottomed parisons formed of synthetic resin to the releasing of hollow molded products such as bottles subjected to the stretching and blow molding.

Abstract: A device for cutting off a sprue of a parison with a bottom is capable of cutting off the sprue in a heating furnace. Cutter plates for cutting the sprue and an outlet for discharging the cut sprue are disposed at the bottom of the heating furnace. Cutting off the sprue may thus be performed without changing the usual molding cycle of the hot parison molding method. The device may alternatively be applied to the cold parison molding method.

Abstract: In an injection molding apparatus in which an injection device imposes a touching force on an injection mold in a direction perpendicular to the direction of the clamping force for closing the mold cavity, an apparatus is provided which imposes a force on the injection mold of an equal magnitude an in an opposite direction to the injection device touching force. The apparatus can be a hydraulic ram which is driven by fluid from the same line that supplies fluid to drive the touching motion of the injection device.

Abstract: An injection blow molder for manufacturing duplex hollow molded articles has four operation stages: An injection molding state, a heating stage, a stretching and blowing stage, and a mold releasing stage and has 1 neck molds more than the number of stages. The injection molding stage is expanded to include the stopping positions of two adjacent neck molds. In the injection molding stage, an inner parison and an outer parison are separately formed; and in the later stages they are stretched and blow molded to form a duplex hollow molded article.

Abstract: The present invention relates to a device for setting a base cup in a blow mold, comprising a pair of divided molds disposed on a machine base and transversely movable for opening and closing and a bottom mold disposed at the bottom of these divided molds; further comprising a horizontal stationary plate secured to the machine base, a carrier capable of reciprocal movement on said stationary plate, and a base body of said bottom mold vertically movably disposed on said carrier, said stationary plate being disposed so as to move beyond the machine base for displacing said bottom mold and said carrier from the center of said blow mold to the outside of said machine base, guiding members being disposed at necessary positions in a drive device for displacing said carrier, said carrier having members for vertically moving said bottom mold at the bottom of said divided molds, a base body being disposed in association with a lifting device, and said carrier and said drive device comprising a transfer device by being

Abstract: A method for the prevention of drooling from a plastic injection molding mold and injection nozzles. The method comprises the steps of varying a volume of a sprue in injection molding mold by movement of a plunger in a nozzle touch member inserted into the sprue, automatically returning the plunger previously moved by the nozzle touch force to its original position as the nozzle touch force decreases when the nozzle moves away after injection molding has been carried out, and increasing the sprue volume equal to an amount of movement thereof more than when injection is made to reduce the residual pressure to the extent that no drooling is introduced while maintaining said nozzle in contact with said nozzle receiver.

Abstract: A nozzle device used for injection-molding plastic products. In the present nozzle device, the hot runner may be formed into a block and set to a mold clamping mechanism irrespective of cavity mold. The device comprises a hot runner block of fixed length having a plurality of nozzles at one side thereof and a sprue at the other side thereof, the nozzles and the sprue being placed in communication with each other by the runner, and a base plate having a plurality of support plates. The nozzles may accessibly come into contact with gates of a cavity mold. In this device, no overheating occurs in the periphery of the gates of the mold.

Abstract: Synthetic resin bottles with base cups are prepared by stretching a parison with a bottom having a sprue at its bottom surface, by means of a stretching rod, to the bottom surface of a base cup having a hole at its center, the base cup being mounted on a bottom mold of a blow mold, the bottom mold having a hole larger than the hole of the base cup, in which a pressing jig is mounted for crushing the sprue formed on the bottom of the parison with a bottom; inserting the sprue into the hole in the bottom of the base cup; crushing the sprue by means of the pressing jig to form a rivet; and, at the same time, blowing air into the parison with a bottom so as to press the outer bottom surface of the parison against the inner surface of the base cup to securely adhere one to the other.

Abstract: A nozzle device used for injection-molding plastic products. In the present nozzle device, the hot runner may be formed into a block and set to a mold clamping mechanism irrespective of cavity mold. The device comprises a hot runner block of fixed length having a plurality of nozzles at one side thereof and a sprue at the other side thereof, the nozzles and the sprue being placed in communication with each other by the runner, and a base plate having a plurality of support plates. The nozzles may accessibly come into contact with gates of a cavity mold. In this device, no overheating occurs in the periphery of the gates of the mold.

Abstract: A mold closing device of an injection molding machine is disclosed which is reliable in operation and simple in structure. Both the opening and closing of the valve for hydraulic oil passage can be attained in the mold closing device of the invention in which two valve controlling oil chambers are formed in the boundary between the valve member and a quick shifting ram. One of the above oil chambers is connected to a forward cylinder and the other, to a return cylinder, thereby attaining the opening and closing of valve by hydraulic pressure in synchronism with the movement of a mold closing piston which is attached to the quick shifting ram.

Abstract: An injection blow-molding machine comprising a pair of female mold-halves attached to a movable plate and a fixed plate respectively with a required number of parison cavities and blow-molding cavities being formed symmetrically in the mating plane of the mold-halves, a required number of male molds each having a blowing hole therethrough ahd supported around a male-mold supporting member fixed to a rotating shaft passed freely rotatably through one of the female mold-halves attached to the fixed plate, a hot-runner block provided adjacently to each of said parison cavities, a hot-runner nozzle disposed between the parison cavity and the hot-runner block, and a gate in the form of a channel provided for each parison cavity for forming the bottom portion of the parison to be apart from said hot-runner nozzle.

Abstract: An injection blow molding machine which is compact but effective in operation. The machine comprises: a machine bed being provided with an injection molding stage having an injection mold and a mold closing mechanism, a heating stage having a heating cylinders, a stretching and blowing stage having a stretching and blowing mechanism and a releasing stage having a molded product releasing mechanism; a base plate which is attached to and above the machine bed leaving a certain space; a rotary disk which is rotatably attached to the under-surface of the base plate; a motor secured to the middle portion on the base plate and interlocked with the rotary disk by an arm and a connecting pin. The invention is characterized in that the space between the machine bed and the base plate carrying the rotary disk is fully utilized for holding mold and other necessary parts.

Abstract: Injection blow molding method for a hollow article having openings at both ends, in which said method comprises the steps of: forming a parison having openings at both ends by injecting plastic material into the cavity of an injection mold which is provided with a stationary core member and a movable core member as disposed on the same axis, shifting said parison from said injection mold to said blow mold together with a movable core member, closing the remaining open end of said parison by a closing core member, and blowing said parison within said blow mold to produce a molded article having openings at both ends.

Abstract: Hydraulic control apparatus for controlling the rate of flow of a fluent plastic from an injection nozzle of an injection molding machine wherein an injection ram is connected to a hydraulic piston in a hydraulic cylinder. The control apparatus controls the pressure exerted by a hydraulic fluid in the cylinder by means of a main hydraulic circuit including the cylinder, a valve and a pump connected in series and a main line pressure valve connecting in parallel a plurality of pilot pressure control valves having different pressure set points to the main line. The pilot pressure control valves are operated in sequence by an electrical relay and timer circuit, or a combination of such circuit and limit switches.

Abstract: An intermittent hydraulic motor which comprises: a crank shaft; a plurality of hydraulic cylinders having pistons engaging with an eccentric member of said crank shaft; pressure oil lines connected to said hydraulic cylinders; check valves having choke valves; and independent changeover valves which connect one of said hydraulic cylinders to a pressure pump and the others to an oil tank; and being characterized in that said crank shaft together with said eccentric member is rotated independently of synchronism with the crank shaft for a certain angle only by the application of oil pressure to said one of the hydraulic cylinders.

Abstract: Injection blow molding method and apparatus for a hollow article having openings at both ends, in which said method comprises the steps of: forming a parison having openings at both ends by injecting plastic material into the cavity of an injection mold which is provided with a stationary core member and a movable core member as disposed on the same line, shifting said parison from said injection mold to said blow mold together with said movable core member, closing the remaining open end of said parison by a closing core member, and blowing said parison within said blow mold to produce a molded article having openings at both ends.

Abstract: Injection blow molding method for producing double layered hollow articles, the method being characterized in that the molding of an outer parison and an inner parison by using injection molds, molding of an outer layer from an outer parison by using one blow mold and molding of an inner layer from an inner parison by using the other blow mold which holding an outer layer formed in the preceding cycle, are carried out simultaneously but in different positions in the apparatus.