Valve gate system
OwnerPanos Trakasinventor
Life of this patent
Estimating the term…
Abstract
A valve gate assembly comprises a piston that is actuable between a forward position and a rear position and has a piston stop surface and a forward pressure surface. A cylinder has a cylinder stop surface that is disposed to contact the piston stop surface when the piston is in the forward position. The cylinder stop surface is radially outward of at least a portion of the forward pressure surface and a shutoff pin is substantially aligned with the axis.
Claims11
A method of in situ purging of a shutoff valve debris chamber of an injection molding apparatus comprising the steps of
- providing a chamber to be axially rearward of a manifold shutoff pin hole, the shutoff pin hole opening onto the chamber, a forward surface of a piston defining a rearward surface of the chamber;
- using an open gate supply port in fluid communication with the forward surface of the piston to displace the piston rearwardly to an open gate position;
- responsive to displacing the piston rearwardly to the open gate position, flowing polymer through a polymer melt flow bore coaxial with the shutoff pin, and through a gate into a mold;
- while performing said step of flowing the polymer, accumulating debris in the chamber resulting from polymer flowing from a polymer melt flow bore through the shutoff pin hole into the chamber;
- after said step of flowing the polymer, positioning the piston in a purging position;
- flowing a purging fluid from the open gate supply port into and through the chamber;
- and
- exhausting the purging fluid and debris out of the mold from an exhaust port in fluid communication with the chamber.
A method of in situ purging of a shutoff valve pin debris chamber of an injection molding apparatus comprising the steps of:
- providing a chamber to be axially rearward of a manifold seal pin hole opening onto the chamber, a forward surface of a shutoff pin piston defining a rearward surface of the chamber;
- accumulating debris in the chamber, the debris resulting from polymer flowing from a polymer melt flow bore through the shutoff pin hole into the chamber;
- positioning the piston in a forward, purging position;
- flowing a purging fluid from a purging supply port into and through the chamber;
- and
- exhausting the purging fluid and debris out of an exhaust port in fluid communication with the chamber.
A method of operating an injection molding apparatus, comprising the steps of:
- using an open gate supply port to admit pressurized fluid into a first chamber forward of a valve gate piston and rearward of a manifold seal pin hole;
- responsive to the last said step of admitting pressurized fluid, displacing the piston, and a valve gate shutoff pin coupled thereto, in a rearward direction, thereby opening a gate to a mold;
- following the last said step of displacing the piston, accumulating debris in the first chamber, the debris resulting from polymer flowing from a polymer melt flow bore through the shutoff pin hole into the first chamber;
- using a close gate supply port to admit pressurized fluid into a second chamber rearward of the valve gate shutoff piston;
- responsive to the last said step of admitting pressurized fluid, displacing the piston and the valve gate shutoff pin in a forward direction, thereby shutting off the gate;
- using the close gate supply port and the pressurized fluid admitted thereby to fix the piston in a forward, purging position;
- and
- while the piston is fixed in the forward, purging position, pressurizing the open gate supply port and opening an exhaust port in fluid communication with the chamber to purge the debris in the chamber out of the exhaust port.
Dependencies are inferred from the claim text.