Pressure control mechanism for a molding apparatus
AssigneeIndustrias Romi S.A.
InventorRomeu Romi
Life of this patent
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Abstract
An injection molding machine having four tie bars extending through and between a movable platen and a fixed platen each of which carry a half of a mold. To enable the movable platen to withstand the forces which arise during a molding process, a pressure control mechanism including a piston in association with each tie bar is received within a corresponding recess provided in the movable platen and in order to grip the tie bars during the molding process a gripping mechanism is provided which is supported by the piston such that the gripping mechanism and the piston effectively form a single movable unit. The gripping mechanism comprises a pair of gripping jaws which are transversely movable and are moved by way of a rotatable disc which is also provided in the single movable unit.
Claims27
A pressure control mechanism for applying pressure to a platen of a molding machine, the pressure control mechanism comprising:
- at least one piston having a longitudinally extending bore therethrough for receiving a tie rod of the molding machine therein, a first front pressure applying surface, and a second rear surface spaced longitudinally from said front surface;
- a gripping mechanism supported on each of said pistons, wherein said gripping mechanism comprises a substantially cylindrical body having a longitudinally extending bore therethrough, a front support surface coupled to the rear surface of said piston such that the bore in said piston and the bore in said substantially cylindrical body are aligned with one another and a pair of gripping jaws operatively coupled in said substantially cylindrical body to be slidably movable with respect to one another and transversely movable with respect to the longitudinal extent of the bore in the substantially cylindrical body;
- moving means structured and arranged to cause relative movement of said gripping jaws towards one another to thereby grip said tie rod extending through said aligned bores, wherein said moving means comprises a rotatable disc operatively coupled to said gripping jaws;
- and
- movement translation means structured and arranged to translate a rotation of said disc into a transverse movement of said gripping jaws wherein said movement translation means comprise slots in one of said gripping jaws and said rotatable disc and corresponding projections carried by the other of said rotatable disc and said gripping jaws, such that upon rotation of said rotatable disc each projection is moved along its corresponding slot to thereby cause transverse sliding movement of said gripping jaws, each of said slots having a first portion and a second portion contiguous with said first portion, wherein said second portion is arranged at an angle relative to said first portion.
A molding apparatus comprising:
- a first and a second relatively movable platen each carrying a respective half of a mold;
- a plurality of tie rods extending between and through the first and second platens for guiding a relative movement of said platens;
- controllable displacement means operatively coupled to said platens for causing said relative movement of said first and second platens to thereby open and close said mold halves;
- a pressure control mechanism operatively coupled to said platens for applying a pressure to said platens to thereby maintain said platens in a closed position, the pressure control mechanism comprising a respective piston and cylinder-unit associated with each of said tie rods, the piston of each of said units having a longitudinal bore formed therein through which the associated tie rod extends, the piston of each of said units having a gripping mechanism operatively coupled thereto and structured and arranged to selectively grip the associated tie rod, wherein each of said gripping mechanisms is structured and arranged for reciprocating movement within with its associated piston, and wherein each of said gripping mechanisms includes a pair of gripping jaws transversely movable with respect to the associated tie rod and to selectively grip the tie rod;
- moving means structured and arranged to cause relative movement of said gripping jaws towards one another to thereby grip said tie rod, wherein said moving means comprises a rotatable disc operatively coupled to said gripping jaws;
- and
- movement translation means structured and arranged to translate a rotation of said disc into a transverse movement of said gripping jaws wherein said movement translation means comprise slots in one of said gripping jaws and said rotatable disc and corresponding projections carried by the other of said rotatable disc and said gripping jaws, such that upon rotation of said rotatable disc each projection is moved along its corresponding slot to thereby cause transverse sliding movement of said gripping jaws, each of said slots having a first portion and a second portion contiguous with said first portion wherein said second portion is arranged at an angle relative to said first portion.
Dependencies are inferred from the claim text.