Abstract: The tip of a ball screw (28) is mounted so as to be rotatable with respect to a pusher plate (14) but immovable in the axial direction. A ball nut (31), which mates with the ball screw (28), is attached to a rear plate (2) through a load cell (33). Even though a force in the rotating direction is applied to the ball nut (31) through friction as the ball screw (28) rotates, the applied force never acts as a force to rotate the pusher plate (14). Thus, the level of sliding resistances between the pusher plate (14) and guide rods has nothing to do with the magnitude of the rotatory force of the ball screw, so that resin pressure components can accurately be extracted from the output of the load cell (33).

Abstract: An apparatus for manufacturing injection molded parts is described with a die and a counter-die and a mold cavity formed therebetween. Both the die and also the counter-die respectively consist of a mold insert which provides the contours and a web-braced body of cast material which receives the respective mold insert in a form-fitted manner, surrounds it and supports it against the injection molding forces which arise.

Abstract: A frame for a die casting machine, including a first side, a second side, a toggle endpiece and a die endpiece opposite the toggle endpiece, one of the first and second sides having an upper frame member with a die end and a toggle end, the die end being releasably secured to the die endpiece, and a lower frame member integrally joined to the die endpiece and the toggle endpiece, the other of the first and second sides having upper and lower frame members integrally joined to the die and toggle endpieces.

Abstract: In a mold clamping apparatus of an injection molding machine using five-point double toggles, a projection (17) is formed at a side of a link (14) of which one end is connected to a rear platen (6), that side being opposite to the side facing a crosshead (18). And a pin is inserted in a through hole formed in the projection (17) and a through hole formed in the other end of a link (16) of which one end is connected to the crosshead, with these through holes being in alignment with each other.

Abstract: An injection molding machine of the present invention includes a first mold half having one of at least one mold cavity and at least one mold core and a rotatable turret block rotatable on an axis for rotating at least one movable mold half thereof into alignment with the first mold half. Each of the movable mold halves include one of at least one mold cavity and at least one mold core matable with the first mold half for forming a mold for molding a molded article. The rotatable turret block is further for clamping the movable mold halves and the first mold half together. The machine further includes a mechanism for moving the rotatable turret block relative the first mold half and a mechanism for rotating the rotatable turret means, wherein the mechanism for moving is linked to the mechanism for rotating, and a first injector for injecting melt into the at least one mold cavity.

Abstract: A driving apparatus for an electrically-operated injection molding machine not requiring any bearing nor any connector. An electric motor having a rotor shaft on which a ball screw is integrally formed is mounted on one of a cross-head and a rear platen of a clamping mechanism, while a ball nut threadedly engaged with the rotor shaft is fixed to the other of the cross-head and the rear platen to constitute the driving apparatus for linearly moving the cross-head. As the ball screw is integrally formed on rotor shaft, any connector for connecting these two members is unnecessary. As the ball screw is directly rotated by the motor positioned coaxially with the ball screw, any bearing for bearing a redial force acting on the ball screw and rotor shaft. The apparatus may also be applied to an ejection mechanism, an injection mechanism and a nozzle touch mechanism of the electrically-operated injection molding machine.

Abstract: A method and apparatus for mold protection of motor-driven clamping unit is provided. The method and apparatus is based on high response characteristics of the motor and a new control method. A continuously variable restrictive motor output scheme is used in conjunction with the mechanics characteristics of the toggle mechanism to maintain a substantially constant mold protective force at all positions. Further, the mold protective force can be adaptively adjusted with respect to different types of molds and motional conditions so that the mold can be adequately protected whenever abnormal condition occurs during mold closing action. The motor output will thus not unduly increased to a great level that would damage the mold, the machine, or even the operators. The drawbacks of the prior art are thus eliminated.

Abstract: A process and an apparatus (10) for the production of a plastic article of large area and small wall thickness, wherein the plastic material (90) is injected in the viscous condition into a mold cavity which is defined by a bottom mold portion (20) and a top mold portion (36). During the operation of injection of the viscous plastic material, which takes place through an inlet (76), the top mold portion (36), with the bottom mold portion (20), forms a pre-molding cavity (86) which is enlarged in a wedge shape starting from the inlet (76). During injection of the viscous plastic material (90) into the pre-molding cavity (86) or immediately after the injection operation, the bottom and top mold portions (20, 36) are moved relatively towards each other, forming the definitive mold cavity (78), so that the viscous plastic material is uniformly distributed in the diminishing mold cavity.

Abstract: An ejector apparatus includes a movable platen disposed facing a stationary platen and adapted for advancing and retracting movement along tie bars, a toggle mechanism disposed between the movable platen and a toggle support so as to advance and retract the movable platen, a servomotor fixed to the movable platen and including a stator and a rotor, a hollow shaft fixed to the rotor, a ball nut fixed to the hollow shaft, a ball screw shaft which is screw-engaged with the ball nut and is advanced and retracted by rotation of the ball nut, a cross head connected to the ball screw shaft so as to be advanced and retracted together with the ball screw shaft, and an ejector pin connected to the cross head. The hollow shaft is rotated by driving the servomotor, thereby advancing the cross head. With this operation, the ejector pin is advanced to push out a molded product.

Abstract: A transfer molding machine for encapsulation of semiconductor devices with a resin comprises a clamping mechanism with an electrically actuated toggle mechanism, a pair of upper and lower sections of a transfer mold, and at least one compensation unit including upper and lower plates and a plurality of elastic members held between said upper and lower plates. The compensation unit is arranged either between the upper stationary platen and the upper mold section or between the moving platen and the lower mold section to compensate the dimensional errors in the mold sections and clamping mechanism.

Abstract: A press for the moulding of plastic materials (or for die-casting) of the type with a double-toggle closing unit, having an additional mobile plate (20) which is guided on columns (14) and can be moved between the closing plate (11) and the mobile mould-holder plate (13) and which has two opposing wings (20') outside the guiding columns (14) turned towards the closing plate (11) and such as to pass outside this when the additional plate (20) is moved towards the closing plate (11) to open the press. The toggles (18) are connected to said wings (20') of the additional plate (20) and turn folding themselves back towards the outside of the columns and towards the closing plate (11) when the additional plate moves from the press closing position to the opening position.

Abstract: A closing unit 1 for mold tools 6 of injection molding machines is provided with a stationary mold support- or base-plate 2, a mold support plate 3 whose spacing can be adjusted relative to the stationary mold support plate by displacement thereof, as well as a drive support plate 4, which is connected to the stationary mold support- or base plate 2 by traction links 5, for instance struts. The traction links 5 can be used at the same time as slide guides for the mobile mold support plate 3 and an electromotor 8 serves as an actuation device for the mobile mold mounting plate 3, which electromotor 18 repositions one or several toggle levers 6 and 7 alternately between a kinked position and a stretched position. The toggle lever system or systems are installed between the drive support plate 4 and the mobile mold molding plate 3 and the mold tool 6 is maintained under closing stress or tension between the two mold support plates 2 and 3 in the stretched position of the toggle lever system or systems 7.

Abstract: In an injection molding machine for processing synthetic materials a machine base is fixedly connected with a stationary mold carrier, with a movable mold carrier and with a closing mechanism, arranged at the closing mechanism, for moving the movable mold carrier. The supporting element is hinged with the stationary mold carrier by at least one force transmitting element adapted to take up forces occuring when the mold is in closed position. Since the force transmitting element is a separate clamping device, deformable by the forces, and the supporting element is movably beared at the machine base in closing direction, whereat linked elements, used for flexible connection are detachably arranged at the supporting element, the stationary mold carrier and the clamping device, it is achieved that deformations occuring at the mold closing unit are deviated to the machine base without having an influence on it, even after a long life and without affecting mold parallelism.

Abstract: An injection molding machine where the movable mold platen 3 and the fixed mold platen 2a are arranged separately of the drive unit 20. The drive unit 20 is located behind the injection unit 1 and connected by pins 9 to the mold section. This arrangement offers the advantage of a cantilevered mold section, which enables maximum accessibility to the major working area.

Abstract: An injection compression molding method in which molten resin of a predetermined amount is injected into a mold cavity during or after a mold closing process. The molten resin is compressed by advancing a crosshead in a first direction to a predetermined stroke position to form a molded piece. Strain of the molded piece is relieved by moving the crosshead in a second direction, which is opposite the first direction, to a predetermined retracted position.

Abstract: An injection molding machine is provided with an open frame specifically designed to avoid angular displacement of the stationary platen during the molding process. More particularly, the stationary platen and the supporting frame are configured to maintain a constant moment of inertia relative to the line of force acting on the platen during the clamp closed part of the cycle, so that it displaces linearly when force is applied. In addition, the frame is provided with integral support members to connect with the die height adjustment mechanism. The support members are positioned on the frame to minimize the distance of the open frame, thus minimizing the length of frame subject to deflection when the force is applied.

Abstract: An injection molding machine, comprising a frame including a first structural member having a stationary platen supporting a first mold half and a second structural member spaced from and connected with the first structural member; a movable platen supporting a second mold half wherein the movable platen is positioned between the first and second structural member and wherein the first mold half and the second mold half have a mold centerline; a device for moving the movable platen relative the stationary platen for closing the first mold half and the second mold half together, wherein the device for moving is connected with the frame; and a mechanism for adjustably spacing said first and second structural members along a first substantially common plane spaced from the mold centerline. Upon closing the first mold half and the second mold half together, the first structural member and the second structural member are caused to separate at least along the mold centerline.

Abstract: A compression equipment possesses generality of various injection molding machine by which injection and mold under compression is performed. The compression equipment is composed as a unit and is installed between a moving die plate of the injection molding press and a moving mold. The compression equipment possesses a moving mechanism containing first tapered members moved by a cylinder and second tapered members contacting with the first tapered members and the moving mold moves toward a stationary mold by the cylinder.

Abstract: A direct drive electro-mechanical press for encapsulating semiconductor devices has at least a clamping axis and a transfer axis. The clamping axis has a planetary roller screw coupled to a tie bar platen assembly on which at least one top mold is mounted. A two-speed gearbox is further coupled to the clamping axis for switching between a high speed mode and a high torque mode along the clamping axis. The two-speed gearbox has a high speed clutch coupled to a speed reducer and a high torque clutch respectively. The transfer axis is slidably located above the clamping axis; the transfer axis has another planetary roller screw coupled to a bottom platen on which at least one bottom mold is mounted. The transfer axis transfers the molding resin from the pot into the cavities formed when the top and bottom molds are clamped together.

Abstract: In a clamping device used in an electric-powered injection machine, a motor support (33) is resiliently supported relative to a rear platen (31), and a motor (35) is fixed to the motor support (33). A toggle mechanism is disposed between the motor support (33) and a movable platen (2), so that the movable platen (2) can be moved by driving the motor (35). A rod (45) is also provided to extend with one end abutable against the rear platen (31) and with the other end supporting the toggle mechanism. A reaction force against the clamping force is transmitted directly to the rear platen (31). Thus, it is possible to enhance the durability of the toggle mechanism and to provide an increased clamping force.

Abstract: In a mold closing unit for use in an injection molding machine for processing synthetic materials arranged on a mounting surface an electro-mechanical drive is applied in a toggle mechanism, at which the driving unit is movably held. The electro-mechanical drive converts a rotational movement of a driving unit into a linear movement for the toggle. The length of the lever and the length of the driving element is less than the distance from the mounting surface to the link points. A quill motor can be provided as a driving unit. This arrangement allows that the linear drive and the mold closing unit can be of a shorter and more compact construction.

Abstract: An injection molding assembly includes an automatic control unit that activates a machine moving mechanism to move an injection molding machine toward a mold unit and further activates the injection molding machine to inject molten foamable material into a mold cavity of the mold unit until the pressure inside the mold cavity reaches a first predetermined value to indicate that a predetermined amount of the molten foamable material has been fed thereto. The control unit activates the machine moving mechanism to move the injection molding machine away from the mold unit and further activates a mold opening mechanism so as to open the mold unit when the pressure inside the mold cavity reaches a second predetermined value to indicate that foaming of the molten foamable material in the mold cavity has been completed.

Abstract: A clamping unit and method thereof, in which a servo-motor mounted on a rear platen is used for driving two ball screws with pre-load hydraulic cylinders so as to actuate the outward-bending toggle mechanism to provide mold-opening and mold-clamping functions; by using a limited space, a servo-motor mounted on the movable platen is used for driving a nut to turn so as to cause the screw and the ejector bar to be moved back and forth; finally, an electric motor on the rear platen will drive a mold-adjusting mechanism, and a servo-motor mounted on the platen is also operated so as to complete the mold adjustment quickly and automatically.

Abstract: A clamping assembly for an injection moulding installation includes a rigid, elongated positioning structure and an elongated clamping structure. A fixed platen is rigidly coupled to the positioning structure and articulatedly coupled to a first end portion of the clamping structure. Longitudinal, axially directed sliding bearings are formed integrally with the positioning structure. The assembly further includes a movable platen slidably supported on the bearings for a free, axially directed displacement with respect to the positioning structure towards and away from the fixed platen. A platen drive unit is articulatedly coupled to a second and opposite end portion of the clamping structure and to the movable platen for imparting that displacement to the movable platen.

Abstract: A mold opening and closing apparatus for an electric injection molding machine which performs mold opening and closing actions by a toggle link mechanism having a first arm rotatably supported by a toggle support, a second arm pivotally joined to the first arm and to a movable platen, and an electric drive device for rotating the first arm. The apparatus includes a coil spring for urging the first arm toward a mold opening position of the first arm. The moment caused by the weight of the first and second arms in their mold clamping positions can be canceled by the virtue of the coil spring, thereby enabling the machine to exhibit improved performance of low-pressure mold clamping force.

Abstract: A batch mixer includes a mixing chamber in which polymeric material such as plastics and rubber is heated and mixed. The material is fed to the mixing chamber through a hopper. The hopper has a door which is swung open and closed by a fluid-actuated cylinder. A locking mechanism is provided to enable the door to be swung only slightly open by excessive pressure build-ups in order to vent the pressure without permitting an appreciable amount of molten material to escape through the door.

Abstract: A screw holding member in which a screw is rotatably provided is guided in a vertical direction by two guide shafts. A ball screw is integrally provided on an upper part of the screw holding member through a load cell. A ball nut screwed to the ball screw is provided internally in an upper base through bearings. A second toothed pulley is fixed to the upper part of the ball nut. The ball nut is rotated by an injection motor through the second toothed pulley. The ball screw and the screw 44 are vertically driven by rotation of the ball nut. The second toothed pulley is formed with a through-hole into which the ball screw is loosely fitted, whereby the ball screw does not protrude from the second toothed pulley even when the ball screw rises.

Abstract: In a drive apparatus for a toggle-type mold clamping mechanism of a vertical injection molding machine, a drive motor movably supported on a guide table via rollers moves horizontally following the vertical movement of a ball screw, when a mold is opened or closed, with keeping the distance between the ball screw and the output shaft of the drive motor constant by means of connecting plates. As the ball screw is rotated by the drive motor via a first pulley, a second pulley and a belt wound around the first and second pulleys, a toggle arm of each of a pair of symmetrical toggle clamping mechanisms is bent to close or open the mold.

Abstract: A machine for molding bonded plastics material, in particular expanded or foamable polystyrene in combination with rigid sheet polystyrene, wherein the rigid material (2) is preformed in a preforming station (1) in a preforming mold (33, 36) while simultaneously separating by a cutter (40) the preformed portion from the rigid sheet of starting material to produce separate preformed pieces, the preformed pieces are moved by a transfer table (27) to a molding station (3) while retained on preforming half-mold (33), foamable material (44) is fed to molding mold (41) and molded and bonded on the preformed pieces with sintering by pulse action of steam (45) and, the final molded articles (P) are discharged at discharge station (6). The half-mold (33) is moved alternately between the preforming station (1) and molding station (3), and cooperates with respective counter-molds (36, 41). The scrap is recovered without being involved in the molding stage.

Abstract: An injection molding machine has a machine frame, a stationary and a movable die platen, as well as a front plate supporting a closure mechanism. The front plate on which the movable die platen is supported via the closure mechanism and the stationary die platen are without bars and connected exclusively via the machine frame. The closing force occurring during the closing process and the lifting force occurring during the injection process between the front plate and the die platen are borne only by the machine frame. The movable die platen is guided on at least one rail supported on the machine frame. The closure mechanism is a toggle joint whose levers are rotatably articulated, on the one hand, at the movable die platen and, on the other hand, at the front plate.

Abstract: An apparatus for molding electronic components. The single-strip molding apparatus has a mold die formed from two mold halves which are movable relative to each other and can be closed upon one another. A leadframe for the component to be molded is placed into a recess in one of the mold halves. Molding material is heated and forced under pressure into the recess containing the leadframe. After the component is molded the mold is opened and the upper half of the mold is cleaned by a combined cleaning-discharge unit. Upon the return stroke of the cleaning-discharge unit, the molded component is removed and the lower half of the mold is cleaned.

Abstract: A lubricating system is installed in a common injection molding machine which includes a stationary mold half unit, a movable mold half unit which can be moved towards and away from the stationary mold half unit, a toggle mechanism coupled with the movable mold half unit so as to be driven to move the movable mold half unit, a mold pressing hydraulic cylinder having a piston rod coupled with the toggle mechanism so as to drive the toggle mechanism, and an oil feed system coupled with the mold pressing hydraulic cylinder so as to provide hydraulic pressure for the mold pressing hydraulic cylinder to drive the toggle mechanism.

Abstract: A positioning correction method for a motor-operated injection molding machine, intended to eliminate waste of power supply to or overheat of servomotors by locking up in an ideal state the motor-operated injection molding machine, which uses a toggle mechanism or crank for mold clamping and other operations. During the lockup period, a load RA acting on a mold clamping servomotor 7 is detected (S8), and a position command value PM for the servomotor 7 is increased or decreased in the next cycle in a direction such that the value of the load RA is reduced, if the value of the load RA is greater than a preset reference value V0 (S12, S13). As a result, a rotation center Q1 of a crank 2 and two opposite ends Q2 of a link 3 are locked up in a straight line, so that a moment of rotation produced by a mold clamping reaction force is removed from the rotation center Q1 of the crank 2.

Abstract: A machine for molding is equipped with a toggle mechanism for moving one of the die-holders. The movable die holder slides on columns. The columns are attached at one end to a stationary die-holder and at another end to a closing plate. The toggle mechanism is preferably a double toggle and connects the closing plate to the movable die-holder. A control ring also slides on the columns and is connected to the toggle mechanism by connecting rods. A hydraulic actuator is used to apply force to the movable die-holder to move it towards and away from the stationary die-holder. The control ring and the connecting rods are designed so that the toggle mechanism extends outside the columns during movement of the movable die-holder away from the stationary die-holder.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is connected with one end of the toggle and is carried on a crosshead guide, and a ball screw is rotatably secured to the movable crosshead to extend in the direction opposite from the molds and through a stationary platen. A ball nut rotatably carried by the stationary platen is in engagement with the ball screw and is drivingly connected with a first motor to axially move the ball screw to provide between the molds a clamping force sufficient to resist separation of the molds during high pressure injection of molding material. A second motor is drivingly coupled with the ball screw and is movable therewith in an axial direction. The second motor is adapted to rotate the ball screw for rapid traverse movement of the movable crosshead to rapidly bring the molds into and out of contact.

Abstract: A close clamp cycle for an injection molding machine in which a toggle locking motion is executed using a plurality of velocities to permit faster clamp operation while maintaining control of the clamp to bring it quietly to its final position without damage to the machine.

Abstract: A device for closing molds of an injection molding machine for plastic which includes a stationary end plate and a mold clamping plate displaceable on traverses. The stationary end plate is connected to the clamping plate by a toggle mechanism having a double toggle lever. The double toggle lever is actuatable by at least two drive units arranged between the end plate and the mold clamping plate, parallel to a main axis of the machine.

Abstract: A plastic molding device for a semiconductor element for plastic molding a semiconductor element on a lead frame, which comprises: an upper platen, a lower platen, and a movable platen movably provided at a tie bar which is provided between said two platens; an upper metal mold and a lower metal mold provided at the upper platen and the movable platen, respectively; a motor for applying a raising force for driving the movable platen; a driving force conversion mechanism for converting the rotation force of the motor into a reciprocative force; and a double toggle mechanism for giving the reciprocative force to the movable platen.

Abstract: A method for controlling clamping force on an injection molding machine by determining a toggle position at which the molds are in initial contact. That toggle position is determined as a function of a selected clamping force and a selected mold protect force and is effective to produce the desired clamping force when the toggle is fully extended.

Abstract: A movable platen structure for an injection molding machine in which the platen is in the form of a box-like structure that includes spaced front and rear plates. The platen structure includes a plurality of longitudinally extending beam members that interconnect the front and rear plates and are positioned in parallel relationship and in a generally rectangular array. The rear plate includes on its rear face a plurality of vertically extending pillow block members for pivotally carrying a pivot pin, the pillow block members having inclined sides that intersect with the rear face of the rear plate. Extending across the front face of the rear plate and opposite from the ends of the respective pillow blocks are an upper and a lower transverse beam member, each of which is formed integrally with the rear plate to provide additional structural stiffening and thereby permit the rear plate to be of a thinner and lighter structure.

Abstract: Part ejection apparatus for ejecting molded parts from a mold carried by a movable platen in an injection molding machine. A plurality of linearly operating hydraulic cylinders are provided to move an ejector bar that is carried along guide rods supported by a movable platen so that the ejector bar moves toward and away from a mold member that is carried by the movable platen. Suitable connections can be provided between the ejector bar and the ejection mechanism of the mold to drive ejector pins carried by the mold for separating the molded part from the mold surface. Additionally, a rotary motor is also carried by the movable platen and has its axis coincident with the longitudinal axis of the movable platen for connection of an output shaft of the motor with a drive mechanism carried by a mold, the drive mechanism suitable for rotating rotatable cores that form internal threads on the molded article.

Abstract: One aspect of the invention is a mechanism for controlling the movements of the plates in a multiple plate mold. The mold is secured to a press in an injection molding system having a support plate and top clamp plate. The mechanism includes a member pivotally mounted to the outside of the mold and an arm attaching the press support plate to the member. In a preferred embodiment, two guides are attached to the press top clamp plate and middle moving plate of a three plate mold. The guides travel in curved channels formed in the member to determine the relative positions of the plates.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is connected with one end of the toggle and is carried on a crosshead guide, and a ball screw is rotatably secured to the movable crosshead to extend in the direction opposite from the molds and through a stationary platen. A ball nut rotatably carried by the stationary platen is in engagement with the ball screw and is drivingly connected with a first motor to axially move the ball screw to provide between the molds a clamping force sufficient to resist separation of the molds during high pressure injection of molding material. A second motor is drivingly coupled with the ball screw and is movable therewith in an axial direction. The second motor is adapted to rotate the ball screw for rapid traverse movement of the movable crosshead to rapidly bring the molds into and out of contact.

Abstract: A clamping cylinder system used in a diecast machine and the like and includes a clamping cylinder and a booster cylinder. The booster cylinder has two chambers different in inner diameters, and a booster piston has a small diameter portion and a large diameter portion, which correspond to the inner shapes of these chambers. During the low pressure of the clamping cylinder, the oil pressure is given to the clamping cylinder, with the booster cylinder being in non-operating condition, and, when a booster operating signal is given, the booster piston is operated. With this arrangement, a boosted pressure force in accordance with the ratio of the area between the small diameter portion and the large diameter portion of the booster piston can be obtained.

Abstract: A method and apparatus for automatically setting the die height platen on a toggle-operated injection molding machine to achieve a desired mold clamping force. A control is provided and contains information relating a desired clamp tonnage with a toggle crosshead displacement, in order to permit setting the die height platen for a particular set of molds so that the clamp, when operated, will automatically provide the desired clamping force between the mold members. The adjustment is provided by moving the die height platen in response to deviations from a predetermined set of conditions, the die height platen being moved by an hydraulic motor and chain drive to shift the die height platen along guide rods that extend between the die height platen and a stationary mold platen.

Abstract: An apparatus for forming objects from a moldable material such as wax. The apparatus includes upper and lower mold pieces having upper and lower mold cavity halves attached thereto. A lever arm extends from the upper mold piece and is pivotally attached to a linear actuator. The upper and lower mold pieces are pivotably connected to one another. Movement of the linear actuator results in opening and closing of the upper and lower mold cavity halves about the pivotable connection of the upper and lower mold pieces.

Abstract: A mold clamping apparatus is provided, including upper and lower toggle sections disposed symmetrically with respect to an axis of the apparatus, each toggle section including a ball screw disposed radially outwardly of the apparatus with respect to the axis, a head threadedly engaged therewith, and links operable to expand and bend with reciprocal head motion along the ball screw, each ball screw being directly coupled to a corresponding one of two servomotors connected to a control circuit section including a pulse width modulation control circuit and two transistor inverters. The mold clamping apparatus has primarily structural components separated from the axis so that flexure of the toggle mechanisms and resultant non-uniformity of a pressing force onto the movable platen are eliminated, and each servomotor is small enough to drive a corresponding one toggle section, so that the resultant mold clamp apparatus is low in cost and high in operational response.

Abstract: An automatic mold thickness adjusting method is provided, which is capable of effecting mold thickness adjustment in a short time by a low-cost mold clamping apparatus using a general-purpose motor for mold thickness adjustment, and of preventing an overcurrent from flowing in the motor. A crosshead is retreated to a position behind a position (LO) for production of a set mold clamping force when the crosshead reaches a lock-up position before a die-touch state is attained, or when the die-touch state is established in a crosshead position before the aforesaid position (LO), and a rear platen is advanced so that the die-touch state is attained.

Abstract: During a mold thickness adjustment process of an injection molding machine, a mold touch position at which the mold halves of a mold contact each other is detected, and the mold temperature is detected by means of thermocouples attached to the mold halves, respectively. Also, the mold thickness is obtained based on the position where a movable platen and a stationary platen of the injection molding machine contact each other, which is obtained previously, and the detected mold touch position.After a molding operation is started, the mold temperature (Tn1, Tn2) is detected in each of molding cycles, and the amount of change of the mold thickness (.DELTA.e) during the period between the preceding cycle and the current cycle is calculated (S14) based on the change of mold tempreature (.DELTA.T) during the period between the two cycles, the mold thickness (e), and the thermal expansion coefficient (k). The mold touch position for the current cycle (P) is obtained (S16) based on the calculated value.

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.