Injection Mold Closing Means Utilizing Variable Closing Pressure Patents (Class 425/DIG223)
  • Patent number: 5993719
    Abstract: A method of producing a laminated molding, such as an air current control valve used in an air conditioner for a vehicle, is made to be united with an facing material having the flexible surface of a basic plate made of resin. When the above laminated molding is produced, a used mold should be split into a stationary mold portion and a movable mold portion. Also, a compression core is provided in the movable mold portion. The facing material is temporarily fixed on a mold-face of the stationary mold portion and a mold-face of the compressive core of the movable mold portion opposite the mold-face of the stationary mold portion, during the aforementioned state, a melting synthetic resin is fed into a mold and then the fed melting synthetic resin is compressed by moving the compression core toward the stationary mold portion.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: November 30, 1999
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Tomokazu Abe, Yoshiaki Saito, Terunobu Fukushima
  • Patent number: 5336462
    Abstract: A molding system has a base, a fixed mold plate secured to the base, a fixed mold half carried on the fixed mold plate, a movable mold plate displaceable on the base longitudinally forward away from the fixed mold half and backward toward the fixed mold half, and a movable mold half carried on the movable plate and fittable with the fixed mold half. A mold-closing apparatus has a pair of main cylinders fixed to the fixed mold half and respective main pistons subdividing the main cylinders into respective front and rear main compartments and each having a piston rod secured to the movable mold plate and formed with a longitudinally extending chamber. A small-diameter fast-closing piston and cylinder are formed in one of the piston rods, and the other piston rod is provided internally with a force-amplifying piston unit. Two flow-control valves and check valves control the system.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: August 9, 1994
    Assignee: Krauss-Maffei AG
    Inventor: Walter Wohlrab
  • Patent number: 4968239
    Abstract: A motor-operated, direct-pressure type mold clamping apparatus is capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in one with a moving platen, is rotated at high speed by a motor through gears and a clutch, so that a die is opened and closed at high speed. In a mold clamping operation, the ball screw is driven with a large rotatory force transmitted through a clutch and gears which, having a high reduction ratio, serve to increase the rotatory force of the motor. Thus, dies are clamped with a large clamping force.
    Type: Grant
    Filed: February 17, 1988
    Date of Patent: November 6, 1990
    Assignee: Fanuc Ltd.
    Inventors: Yoshiharu Inaba, Fumio Mitoguchi, Hiromasa Yamashita
  • Patent number: 4904177
    Abstract: A vertical press for the moulding of plastics materials, particularly thermosetting plastics materials includes a fixed plate and a movable plate slidable on guide columns, a first fluid-operated actuator for moving the movable plate along the guide columns, fluid-operated clamps associated with the movable plate for clamping the movable plate relative to the guide columns, and a second fluid-operated actuator acting on the guide columns to move the columns vertically relative to the fixed plate.
    Type: Grant
    Filed: November 18, 1988
    Date of Patent: February 27, 1990
    Assignee: Fiat Auto S.p.A.
    Inventor: Franco Chiesi
  • Patent number: 4865537
    Abstract: In the present invention, an inner space of a clamping cylinder is divided into a front oil chamber and a rear oil chamber for liquid pressure by a piston section of a clamping ram, the front oil chamber and the rear oil chamber are connected with each other by a connecting path which is bored in the piston section of the clamping ram, and the front oil chamber is connected to a charge tank via a second open-close valve. In the clamping ram, an oil chamber for mold closure and an oil chamber for mold opening are formed by slidably fitting a high speed piston therein. A first open-close valve, which opens or closes the connecting path of the piston section of the clamping ram, is slidably fitted on the rear end section of the clamping ram. An oil chamber for valve opening, which is formed between the first open-close valve and the outer face of the clamping ram, is connected to the oil chamber for mold opening via a through-hole bored in the clamping ram.
    Type: Grant
    Filed: September 29, 1988
    Date of Patent: September 12, 1989
    Assignee: Nissei Jushi Kogyo Kabushiki Kaisha
    Inventor: Yoshiharu Shima
  • Patent number: 4822274
    Abstract: A hydraulic clamp unit for a molding apparatus has a pair of opposed complimentary mold halves attached accordingly to a pair of opposed platens suspended on roller guides and moving toward each other into engagement of the mold halves to form a mold cavity surrounding a molded article of a thermoplastic material. The unit is provided with main clamp cylinders of a pull type and having piston rod chambers pressurized to exert pressure on the platens during formation of the article. Rapid movement of the platens is achieved by means of kicker cylinders having piston chambers and piston rod chambers communicating with each other. The main cylinders are locked to one of the platens by means of hydraulic mechanisms.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: April 18, 1989
    Inventors: Harry Chan, Basilio Yi
  • Patent number: 4797086
    Abstract: A molding machine which performs molding by means of one mold part held by a fixed platen and the other mold part held by a movable platen movable toward and away from the one mold part. A shaft having an axis extending in the direction of reciprocal movement of the movable platen is disposed on a stationary frame for rotation with respect thereto and for reciprocal movement along the axis of the shaft, and is rotated by an electrical motor. First and second nut members are respectively screwed onto first and second threaded portions formed along the axis of the shaft. The first nut member is secured to one of the stationary frame and the movable platen while the second nut member is capable of being rigidly coupled with the other thereof via a clutch. While the shaft is being rotated, the second nut member is rigidly coupled with the other of the stationary frame and the movable platen via the clutch, a relative movement is produced between the shaft and the first and second nut members.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: January 10, 1989
    Assignee: Sumitomo Heavy Industries Ltd
    Inventor: Taira Adachi
  • Patent number: 4605367
    Abstract: A mold closing unit of an injection molding machine has a hydraulic traveling cylinder and a hydraulic mold closure retention cylinder for the movable mold clamping plate. One-half of a divided injection mold is clamped on the plate and defines with a fixed mold die a mold cavity having a larger volume at the commencement of the mold charge than at the termination of the mold charge. A threaded spindle is engaged with the movable mold clamping plate through a spindle nut, and the spindle is freely rotatable in the stationary mold clamping plate and is connected with a stepping motor. A 4/2-way valve is arranged in the hydraulic supply line leading to the traveling cylinder, and its valve body is axially shiftable on the spindle. The stepping motor is controlled depending on a specified pressure and/or speed pattern as a function of the distance between the mold halves or the mold clamping plates.
    Type: Grant
    Filed: August 1, 1984
    Date of Patent: August 12, 1986
    Assignee: Klockner-Werke Aktiengesellschaft
    Inventor: Lothar Gutjahr
  • Patent number: 4599063
    Abstract: An injection molding apparatus having movable die operated by a piston and cylinder, includes a hydraulic circuit having a supply line for closing and opening the movable die. A branch line from the supply line leads into a die locking chamber defined between the piston and cylinder, and a first multi-directional control valve is provided for control of the closing mechanism. A second multi-directional valve is located in the branch line for feeding hydraulic fluid into the die locking chamber as sensed by a pressure sensor in the supply line. A threaded spindle meshes with a support for the movable die which feeds back the rate of travel and pressure exerted by the movable die to a stepping motor which varies the spindle rotation in accordance with the rate and the pressure.
    Type: Grant
    Filed: February 2, 1983
    Date of Patent: July 8, 1986
    Assignee: Klockner-Werke Aktiengesellschaft
    Inventor: Lothar Gutjahr
  • Patent number: 4592714
    Abstract: A mold closing unit of an injection molding machine has a threaded spindle which is engaged with the movable mold clamping plate of the machine via a spindle nut. The spindle is attached to the stationary mold clamping plate of the machine in a freely pivotable manner, and is connected with a stepping motor by means of a coupling. The stepping motor is controlled depending on a specified speed pattern as a function of the distance between the mold halves of the mold clamping plates. The valve body of a 4/2-way valve engages the spindle for relative axial movement and controls the hydraulic operating medium for the mold closing unit. A switch is arranged in the casing of the valve which can be triggered by the coupling and which actuates, for example, an indication system when a mold closure security error occurs.
    Type: Grant
    Filed: August 1, 1984
    Date of Patent: June 3, 1986
    Assignee: Klockner-Werke Aktiengesellschaft
    Inventor: Lothar Gutjahr
  • Patent number: 4592713
    Abstract: A mold closing unit has a multi-way valve in a hydraulic supply line leading to a hydraulic traveling cylinder which is controlled as a function of a speed pattern specified for the movable mold clamping plate. The valve body of this multi-way valve is arranged on an elongated, threaded rotatable spindle in an axially movable manner. The spindle is connected with a stepping motor which is controlled as a function of the speed pattern. As soon as the movable mold clamping plate has reached a predetermined distance from the stationary mold clamping plate, the stepping motor is switched to a higher number of steps per revolution and the mold is closed below the creep rate.
    Type: Grant
    Filed: August 1, 1984
    Date of Patent: June 3, 1986
    Assignee: Klockner-Werke Aktiengesellschaft
    Inventor: Lothar Gutjahr
  • Patent number: 4588364
    Abstract: A clamp mechanism for selectively locking and unlocking a first member in a first position relative to a second member comprises a linkage system connecting the first and second members and drive means for articulating the linkage system for moving the first member relative to the second member. A fluid link is provided for locking the first member in position relative to the second member wherein the fluid link is actuated upon sensing the first member approaching the first position.
    Type: Grant
    Filed: April 1, 1985
    Date of Patent: May 13, 1986
    Assignee: Husky Injection Molding Systems Ltd.
    Inventor: Robert D. Schad
  • Patent number: 4509910
    Abstract: A clamp assembly for selectively clamping a movable cross-head assembly to each column of a press having a plurality of columns. The clamp assembly includes an inner clamp sleeve positioned concentrically about each column. The inner clamp sleeve is slidably longitudinal with respect to the column and has an inner generally cylindrical surface for engaging the column. An outer clamp sleeve is secured to the cross-head assembly concentrically about the inner clamp sleeve. The inner and outer clamp sleeves are threadeably secured together to limit longitudinal movement of one clamp sleeve with respect to the other. Although threaded together, there is sufficient clearance between the opposing threads of the inner and outer clamp sleeves to define a helical chamber therebetween. A hydraulic fluid system is provided for selectively introducing pressurized hydraulic fluid into the helical chamber.
    Type: Grant
    Filed: November 18, 1983
    Date of Patent: April 9, 1985
    Assignee: MTS Systems Corporation
    Inventor: Paul S. Petersen
  • Patent number: 4443179
    Abstract: An apparatus for closing a mold in an injection-molding operation has a double-acting main piston that is connected to a mold-carrying plate and that move axially in a main cylinder. A rapid-action piston extends into a small-diameter bore in the main piston, and the rear cylinder wall is formed with a large-diameter fill passage connected directly to a sump. A positioning cylinder is fixed on the main cylinder and contains a positioning piston axially fixed on the rapid-action piston and having in the positioning cylinder a rearwardly directed face larger than the face of the rapid-action piston and forming with the positioning cylinder a pressurizable positioning chamber. A passage extends axially through the rapid-action piston from its cylinder to the positioning chamber.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: April 17, 1984
    Assignee: Krauss-Maffei AG
    Inventor: Walter Wohlrab
  • Patent number: 4345890
    Abstract: An injection mold with locking device comprises a fixed backing plate and a fixed mold part plate which are connected to each other by four tie rods. A movable mold part plate is connected to the fixed backing plate through a drive and locking mechanism which is capable of moving the movable mold part plate into a mold position with the fixed mold part plate. A thermal force control apparatus is associated with one or more of the tie rods for changing the temperature of the tie rods and thereby causing the tie rods either to expand or contract. By such expansion or contraction, the exact force applied between the fixed and movable mold part plates can be adjusted to a desired level.
    Type: Grant
    Filed: June 6, 1980
    Date of Patent: August 24, 1982
    Assignee: Netstal-Maschinen AG
    Inventors: Peter Hemmi, Richard Schrepfer
  • Patent number: 4345893
    Abstract: A molding machine for die casting, injection molding, and other similar processes, comprises a base shaped to support thereon a two-part die, and a ram for converging and diverging the die halves between open and closed positions. A pair of clamping frames are pivotally mounted on one end of the base, and include a closed border shaped to surround or receive therein side portions of the die halves. The clamping frames are laterally pivoted between a fanned-apart or open position wherein the die can be freely lifted off of the base, and a folded or closed position wherein the frame borders surround the die side portions and capture the same between the ends of the frames. In the closed position, retractable compression columns extend between the die and one end of the frames to positively lock the die halves in the closed position, whereby die separation forces developed during injection of the die are resisted substantially solely by the clamping frames.
    Type: Grant
    Filed: October 20, 1980
    Date of Patent: August 24, 1982
    Assignee: Prince Corporation
    Inventor: Edgar D. Prince
  • Patent number: 4273524
    Abstract: In a molding press having fixed and movable platens for mounting mold halves, the movable platen is connected through thrust rods and a thrust plate to the movable component of an hydraulic piston-cylinder platen drive unit the fixed component of which is attached to a fixed base. A high pressure piston-cylinder mold clamping unit of the pancake type interengages the movable platen and a pancake cylinder support plate mounted for movement along the thrust rods and arranged for abutment by the thrust plate. The pancake cylinder support plate and fixed base are joined together by toggle joints operated by a piston-cylinder locking unit supported pivotally on arms extending pivotally from the pancake cylinder support plate and fixed base. The drive unit thus is arranged in parallel with the series arrangement of the toggle joints and mold clamping unit.
    Type: Grant
    Filed: October 18, 1978
    Date of Patent: June 16, 1981
    Assignee: Hull Corporation
    Inventor: John A. Smith
  • Patent number: 4222730
    Abstract: An arrangement in connection with the die closing unit of an injection molding machine for interchangeably mounting to the rear side of the stationary die carrier plate differently spaced pairs of tie rods of injection units of different size, using two tie rod mounting sockets whch are clampable to the die carrier plate and thereby also serve to produce an axial preload on the tie rod connections of the die closing unit in the die carrier plate.
    Type: Grant
    Filed: August 30, 1979
    Date of Patent: September 16, 1980
    Inventor: Karl Hehl
  • Patent number: 4091062
    Abstract: A method and apparatus for forming cured polyethylene insulation about high voltage cables by applying uncured polyethylene around a core of the cable. The polyethylene is heated, cured and then cooled to room temperature in a pressurized nitrogen gas atmosphere. In one form the molding apparatus comprises first and second mold forms which define a cavity and which include means for heating the mold halves to the polyethylene curing temperature. Means is also provided to introduce the pressurized nitrogen into the cavity and for subjecting cable portions that extend beyond the mold to pressurized nitrogen until such cable portions are sufficiently cooled to prevent their deformation under pressure, to prevent the oxidation of polyethylene and/or to prevent the formation of voids or enclosures.
    Type: Grant
    Filed: January 15, 1975
    Date of Patent: May 23, 1978
    Assignee: Townsend & Townsend, trustee
    Inventor: Arthur L. Nelson
  • Patent number: 4047871
    Abstract: A push-type die closing unit for injection molding machines in which a stationary die carrier plate, a rearwardly spaced head plate, and four tie rods form a rigid guide structure for a movable die carrier frame to which the piston rod of a linear actuator with power cylinder and auxiliary cylinder is centrally connected, for the direct and cant-free transmission of elevated closing pressures to the die carrier frame and die. The die carrier frame has axially spaced walls joined by four guide sockets and by pressure transfer ribs, a central accessory space defined therebetween accommodating, in conjunction with a hollow forward portion of the piston rod, an ejection device or other accessory device and a hydraulic drive therefor.
    Type: Grant
    Filed: September 4, 1975
    Date of Patent: September 13, 1977
    Inventor: Karl Hehl
  • Patent number: 4032277
    Abstract: Two halves of a split mold of an injection molding machine are respectively mounted on a stationary plate and a movable plate guided on guide rods projecting from the stationary plate for movement toward and away from the latter. A guide plate, likewise guided on said guide rods, is connected to the movable plate for movement therewith, and a moving arrangement is connected to the guide plate for moving the same and the movable plate connected thereto toward and away from the stationary plate to thus move the mold halves between an open and a closed position. The guide plate includes a clamping arrangement for clamping the guide plate in fixed position on the guide rods and a hydraulically operated arrangement for holding the mold halves in closed position against the force of molding material injected under pressure into complementary cavities in the mold halves.
    Type: Grant
    Filed: November 5, 1975
    Date of Patent: June 28, 1977
    Assignee: Klockner-Werke AG
    Inventors: Joachim Linde, Wolfgang Spath
  • Patent number: 4025266
    Abstract: An injection molding machine includes a stationary frame having a pair of spaced upright stationary plates which guide rods of a movable frame which includes, at opposite ends of the rods projecting beyond the stationary plates, a pair of movable plates. One of the stationary plates and the movable plate adjacent thereto respectively carry complementary parts of a split injection mold. A unit including a pressure plate fixed to the other stationary plate is arranged on the rods between the other of the stationary plates and the movable plate adjacent thereto. Cylinder and piston arrangement connects the unit and the movable plate adjacent thereto for moving the movable frame relative to the stationary frame and therewith the mold parts between open and closed positions.
    Type: Grant
    Filed: November 5, 1975
    Date of Patent: May 24, 1977
    Assignee: Klockner-Werke AG
    Inventors: Joachim Linde, Wolfgang Spath
  • Patent number: 4025264
    Abstract: A die closing unit for an injection molding machine, where the closing force is provided by either push-type or pull-type hydraulic cylinders, the die closing unit having in each case a movable die carrier member and a stationary die carrier member and two or four tie rods rigidly connected to one member, while guidingly engaging the other, the tie rods being releasable at their connections and retractable for the emplacement of an injection molding of enlarged contour.
    Type: Grant
    Filed: December 15, 1975
    Date of Patent: May 24, 1977
    Inventor: Karl Hehl
  • Patent number: 4021181
    Abstract: A tie rod connection for the die closing unit of an injection molding machine in which the tie rods, extending on either side of the injection molding die between die plates or other thrust members, are connected thereto with a connection that includes a split abutment ring received inside a groove of the tie rod located outside the thrust member and a clamping cap retaining the abutment ring while preloading the connection between the tie rod and the thrust member.
    Type: Grant
    Filed: May 25, 1976
    Date of Patent: May 3, 1977
    Inventor: Karl Hehl
  • Patent number: 4013392
    Abstract: In an injection moulding machine comprising two relatively movable platens each carrying a mould part, a stop means is provided which, in a first condition, defines a limit to the relative approach movement of the platens, and in a second condition permits further relative approach movement of the platens, means being provided to change the condition of the stop means from the first to the second condition at a predetermined instant after interruption of the relative approach movement of the platens by the stop means.
    Type: Grant
    Filed: May 3, 1974
    Date of Patent: March 22, 1977
    Assignee: G.K.N. Windsor Limited
    Inventor: Samuel Charles Henry Smith
  • Patent number: 4009983
    Abstract: A mold clamping mechanism for an injection molding machine characterized in that a relatively large mold clamping cylinder has a passage in its piston intercommunicating the head and rod ends of said mold clamping cylinder during stroking of said piston by a relatively small actuating cylinder for flow of oil from said head end into said rod end and into a makeup fluid tank having a capacity corresponding to the displacement of the piston rod of said mold clamping piston and vice versa during the respective mold opening and closing strokes. To effect mold clamping at required tonnage, the mold clamping cylinder has a port through which fluid under high pressure is admitted not only into the mold clamping piston to act on a fluid pressure actuated valve therein to close said passage, but also into the head end of the mold clamping cylinder to pressurize the fluid trapped therein by the closing of said passage.
    Type: Grant
    Filed: January 16, 1976
    Date of Patent: March 1, 1977
    Inventor: Arthur William Jacobs
  • Patent number: 4005974
    Abstract: A mold closing unit for an injection molding machine having a double acting mold closing piston, a closable valve interconnecting both sides of the piston, an auxiliary piston, and a piston rod for each piston, each connecting one side of the pistons to the movable mold part wherein the cylinder spaces on mold closing side of the two pistons are permanently communicated whereby the change in volume of the combined working space is proportional to the areas of the piston rods. The cylinder for the auxiliary piston is placed laterally of the main cylinder so that the overall length of the machine is held to a minimum. An additional return piston is also provided.
    Type: Grant
    Filed: January 24, 1975
    Date of Patent: February 1, 1977
    Assignee: Tibor Szabo
    Inventor: Tibor Szabo
  • Patent number: 3976416
    Abstract: A knee linkage type die closing unit for an injection molding machine where the thrust stock engaged by the knee linkage is longitudinally adjustable along a threaded length of the guide spars, fine-adjustment being performed by an internally threaded worm gear on each guide spar and a common shaft with worms mounted thereon, the worm gear being clampable externally between a recessed face and a clamping plate and internally against the guide spar thread, by means of a rotatably connected, also internally threaded, clamping sleeve.
    Type: Grant
    Filed: July 19, 1974
    Date of Patent: August 24, 1976
    Inventor: Karl Hehl
  • Patent number: 3975133
    Abstract: A closure mechanism for an injection molding machine or extrusion press having a frame, a number of parallel extending rods, a first tool support fixedly connected with the frame and a second tool support displaceable along said rods. There is also provided a hydraulic mechanism or device for displacing the second tool support along the rods. According to the invention the rods possess engaging means and the second tool support possesses engaging elements which can be engaged in the engaging means of the rods. The rods are displaceably connected with the first tool support and the hydraulic device possesses at least one displacement mechanism serving to displace the second tool support with respect to the rods and for each rod possesses an additional displacement mechanism fixedly connected with the first tool support which serves to displace the relevant rod with respect to the first tool support.
    Type: Grant
    Filed: December 23, 1974
    Date of Patent: August 17, 1976
    Assignee: Patent & Inventions Ltd.
    Inventor: Thomas Nussbaumer
  • Patent number: 3941549
    Abstract: A reciprocating screw injection molding machine characterized in that the screw is actuated by coaxial hydraulic rotary and linear motors, and in that a movable mold supporting platen has a clamping piston thereon which is reciprocable in a clamping cylinder, the latter having mounted thereon platen and valve actuating cylinders which are operatively secured to the clamping piston and to a valve member respectively to effect movement of the clamping piston and movable mold supporting platen toward and away from a fixed mold supporting platen and to open the valve member for flow of oil from a prefill tank into the clamping cylinder chamber and vice versa, said valve actuating cylinder further being operative upon closing of the mold to close the valve and to admit fluid under pressure into the clamping cylinder chamber to pressurize the trapped fluid therein to lock the clamping piston and movable mold supporting platen in mold closing position with required tonnage for injection of plasticized material into
    Type: Grant
    Filed: June 26, 1974
    Date of Patent: March 2, 1976
    Inventor: Arthur W. Jacobs
  • Patent number: 3941548
    Abstract: An injection mold assembly having mold members which are movable relative to one another between closed molding positions to permit injection molding of parts within mold cavities formed by the members and open positions to permit removal or ejection of the molded parts from the cavities. The mold members are interconnected by hydraulically interconnected and powered actuator means which effect opening and closing movement of the mold members in unison. The described mold assembly includes outer mold members comprising core plates having cores which project into cavities in a central mold member to to form the mold cavities when the mold is closed and stripper plates between the central member and core plates.
    Type: Grant
    Filed: October 16, 1974
    Date of Patent: March 2, 1976
    Inventor: Robert G. Bruder
  • Patent number: RE33248
    Abstract: A clamp mechanism for selectively locking and unlocking a first member in a first position relative to a second member comprises a linkage system connecting the first and second members and drive means for articulating the linkage system for moving the first member relative to the second member. A fluid link is provided for locking the first member in position relative to the second member wherein the fluid link is actuated upon sensing the first member approaching the first position.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: July 3, 1990
    Inventor: Robert D. Schad