Probe assembly for injection molding apparatus

A probe assembly for use in an injection molding apparatus including a manifold source of molten molding material under pressure and a mold having at least one mold cavity and a gate for molding material and a gate cavity adjacent to a mold cavity comprising:

• a probe including a body defining a molding material passage for receiving molten molding material from said manifold, at least one outlet on a front face of said body;
• said front face of said body defining a first reference plane;
• said outlet communicating with a mold cavity to supply molten molding material thereto;
• means mounting said probe with the front face on a mating reference plane with respect to said mold;
• said probe body comprising a pair of partially telescoping parts, a first of said parts including said front face first reference plane and a second of said parts defining a second face providing a second reference plane;
• means for maintaining said first and second reference planes at a substantially fixed distance throughout normal molding operations;
• whereby changes in length of said probe due to thermal effects are compensated by changes in the amount of partial telescoping of said body parts without affecting the overall combined length of said probe body telescoping parts and said substantially fixed distance between said first and second reference planes.

In an injection molding apparatus having a manifold for supplying molten molding material, the manifold defining a first reference plane and said injection molding apparatus including a mold defining at least one mold cavity and the mold defining a second reference plane, wherein the improvement comprises;

• a probe comprising a two part body;
• said body comprising a first body part and a second body part, said second body part overlapping said first body part wherein a longitudinally extending molding material passage extends through said first and second body parts;
• each of said first and second body parts including a respective surface mating with one of said reference planes;
• the amount of overlapping of said body parts being a function of the thermal expansion of said body parts;
• said first and second body parts defining a molding material cavity therebetween for providing molding material pressure biasing said body parts apart and each of said body parts toward a respective one of said reference planes.

A temperature compensated probe assembly for an injection molding apparatus adapted to be located between a source of molten molding material and a mold having at least one cavity;

• said probe assembly having a longitudinal axis and comprising first and second probe parts;
• said first probe part including a surface adapted for sealing engagement with the source of molding material and including a passage therethrough communicating with the source of molten molding material;
• said second probe part including a surface adapted for sealing engagement with said mold and including at least one molding material passage therethrough;
• wherein said first and second probe parts are in sealed overlapping relationship whereby changes in length due to thermal expansion of either part along the longitudinal axis changes the overlap without changing the sealing engagement of respective sealing surfaces on the source of molten molding material and the mold;
• wherein the passages of said first and second probe parts are in communication whereby molding material under pressure may flow from the source of molten molding material to the mold;
• wherein said probe parts define a molding material holding recess therebetween;
• and
• wherein said molding material holding recess and said passage have a lateral dimension normal to the longitudinal axis of said probe assembly, the lateral dimension of said recess being greater that the lateral dimension of said passages.

A probe assembly for an injection molding apparatus, comprising:

• a probe outer body and a probe inner body operably arranged in telescoping relationship relative to each other and having a molding material passage therethrough;
• the probe inner body having a rear mounting surface for mounting with said passage in communication with a source of molding material;
• the probe outer body having an outermost surface and including at least one runner communicating with said passage and the front face of said probe outer body parts;
• said front face of said probe assembly having at least one molding material orifice communicating with at least one mold cavity through said runner and said outlet;
• the front face of said probe being in sealing relationship about said mold cavity;
• the telescoping relationship of said probe body parts defining an annular molding material filled recess when the probe is supplied with molding material;
• said annular recess having a transverse cross-section greater than the combined cross section of said orifice whereby molding material within said annular recess applies sealing pressure between the probe and the mold and said source of molding material.

A temperature compensated probe assembly for an injection molding apparatus adapted to be located between a source of molten molding material and a mold having at least one cavity;

• said probe assembly having a longitudinal axis and comprising first and second probe parts;
• said first probe part including a surface adapted for sealing engagement with the source of molding material and including a passage therethrough communicating with the source of molten molding material;
• said second probe part including a surface adapted for sealing engagement with a mold and including at least one molding material passage therethrough;
• said first and second probe parts in sealed overlapping relationship whereby changes in length due to thermal expansion of either part along the longitudinal axis changes the amount of overlapping relationship without changing the sealing engagement of respective sealing surfaces on the source of molten molding material and the mold;
• said first and second probe parts defining a molding material filled recess therebetween;
• wherein the passages of said first and second probe parts are in communication whereby molding material under pressure may flow from the source of molten molding material to the mold and the pressure of molding material in said recess biases said first and second mold parts apart respectively toward said source of molten molding material and said mold.