Clamping system

A clamping system comprising:

• a fixed platen for holding a fixed mold, said fixed platen being fixedly mounted to one end of a machine base and having a plurality of clamping cylinders;
• a movable platen for holding a movable mold, said movable platen being fixed to the other end of the machine base and movable to and from said fixed platen;
• said plurality of cylinders each defining a cylinder bore therein;
• a plurality of tie bars one end of each of which extends through said movable platen and the outer circumference surface of the other end of each of which has a male screw;
• cylinder-like pistons each of which is slidable within said cylinder bore and has a female screw provided on the inner circumference surface that is meshed with said male screw of each of said tie bars;
• screw threads or grooves each cf which is formed at a substantially longitudinal center of said tie bar;
• means for moving said movable platen to and from said fixed platen;
• a plurality of two-part nuts mounted to said movable platen and engageable with said screw threads or grooves of said tie bars, said two-part nuts being movable to and from said tie bars;
• means for moving said plurality of two-part nuts to and from said tie bars;
• and
• means for rotating said pistons around their axes;
• whereby said tie bars are moved forward or backward by rotating said pistons according to the thickness of said movable mold and fixed molds.

A clamping system comprising:

• a machine base,
• a fixed platen fixedly mounted on the machine base and having a fixed mold and a plurality of clamping cylinders,
• a movable platen fixed to the machine base to be movable relative to the fixed platen, said movable platen having a movable mold;
• a plurality of tie bars extending from the fixed platen and passing through the movable platen, each tie bar having an outer surface with a male screw at a side of the fixed platen and grooves at a center area thereof,
• means for moving said movable platen relative to the fixed platen along the tie bars,
• means for fastening the movable platen to the tie bars, said fastening means being fixed to the movable platen and operating so that when the movable platen is moved at a predetermined position by means of said moving means, said fastening means engages the grooves on the tie bars to immovably fix the movable platen to the tie bars,
• a plurality of pistons rotatably retained in the clamping cylinders of the fixed platen, each piston being moved in the direction parallel to the tie bars when tightening the movable mold to the fixed mold and having a female screw meshing the male screw of the tie bar, and
• means for rotating the pistons attached to the fixed mold, said rotating means, when operated, moving the tie bars relative to the fixed platen to thereby adjust a distance between the movable mold and the fixed mold.