Compression molding apparatus

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening open to a substantially flat surface and a cutting means for cutting the plastic material extruded from the extrusion opening and feeding it to the molding die means;
• the cutting means including a rotating shaft extending substantially perpendicularly to said flat surface to which the extrusion opening opens, a rotating cutting blade mounted on the rotating shaft and a driving source for rotating the rotating shaft;
• the rotating cutting blade is mounted on the rotating shaft so that it can pivot freely over at least some angular range about a first axis extending substantially perpendicularly to the rotating shaft and over at least some angular range about a second axis extending substantially perpendicularly to the first axis;
• and a spring means is provided for elastically biasing the rotating shaft in a direction to press the rotating cutting blade against said flat surface to which the extrusion opening opens, the rotating shaft extending beyond the flat surface to which the extrusion opening opens from behind said flat surface, the rotating cutting blade is mounted on the forward end of the rotating shaft, and the spring means elastically biases the rotating shaft rearwardly, the rotating shaft has formed therein a through-hole extending in the direction of the first axis, the rotating cutting blade has formed therein a shaft insertion hole extending axially of the rotating shaft and a pin receiving hole extending in the direction of the first axis and opened forwardly, and the rotating cutting blade is mounted on the rotating shaft by inserting the rotating shaft into the shaft insertion hole and then inserting a pin into the through-hole and the pin receiving hole,
• the inside diameter of the shaft insertion hole is larger than the outside diameter of the rotating shaft so that the rotating cutting blade can pivot about the first axis in alignment with the central axis of the pin, and
• the through-hole has a size larger than the outside diameter of the pin in the axial direction of the rotating shaft and substantially equal to the outside diameter of the pin in the direction of the second axis, the through-hole has a front wall of an arcuate depressed or raised shape having a center at the second axis, the front surface of the pin has formed therein an arcuate raised or depressed portion corresponding to the arcuate depressed or raised front wall whereby the pin and the rotating cutting blade can pivot about the second axis with respect to the rotating shaft.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means has an extruding means for extruding a molten plastic material through an extrusion opening open to a substantially flat surface, and a cutting means for cutting the plastic material extruded through the extrusion opening and feeding it to the molding die means;
• the cutting means includes a rotating shaft extending substantially perpendicularly to the flat surface to which the extrusion opening opens, a rotating cutting blade mounted on the rotating shaft and a driving source for rotating the rotating shaft;
• the rotating shaft is mounted axially movably, and there are provided a spring means for elastically biasing the rotating shaft in a direction to press it against the flat surface to which the extrusion opening opens, and a rotating shaft moving means for moving against the elastic biasing action of the spring means the rotating shaft in a direction in which the rotating cutting blade moves away from the flat surface to which the extrusion opening opens.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening open to a surface and a cutting means for cutting the plastic material extruded from the extrusion opening and feeding it to the molding die means;
• the cutting means includes a rotating shaft, a rotating cutting blade mounted on the forward end portion of the rotating shaft and disposed on said surface to which the extrusion opening opens, and a driving source for rotating the rotating shaft;
• and
• a cooling medium flow passage is formed in at least the forward end portion of the rotating shaft so that at least the forward end portion of the rotating shaft is cooled by passing a cooling medium through the cooling medium flow passage.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening and a cutting means for cutting the plastic material extruded through the extrusion opening and feeding it to the molding die means;
• the extruding means includes a die head to the surface of which said extrusion opening opens, and the cutting means includes a rotating cutting blade mounted so as to rotate across the extrusion opening and a driving means for rotating the rotating cutting blade whereby the plastic material extruded from the extrusion opening is cut by the rotating cutting blade and carried to the lower edge of said surface of the die head incident to the rotation of the rotating cutting blade;
• and
• the die head has provided therein gas stream jetting means for jetting gas streams downwardly or forwardly from the lower surface of the die head thereby to prevent the plastic material carried to the lower edge of the surface of the die head from moving to the lower surface of the die head and to aid in its leaving from the rotating cutting blade so that the plastic material is dropped while drawing a required track fully stably.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening, a cutting means for cutting the plastic material extruded thriough the extrusion opening and dropping it toward the molding die means, and a feed hampering means for selectively hampering the feeding of the plastic material to the molding die means;
• and
• the feed hampering means includes a receiving member mounted for free movement between an operating position located in a path of dropping of the plastic material toward the molding die means and a non-operating position spaced from the dropping path, and a positioning means for selectively holding the receiving member at the operating position and the non-operating position.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening and cutting means for cutting the plastic material extruded through the extrusion opening and feeding it to the molding die means;
• the cutting means includes a rotating cutting blade mounted so as to rotate across the extrusion opening, a driving source and a drivingly connecting means for drivingly connecting the driving source to the rotating cutting blade;
• the drivingly connecting means includes at least one rotating angular position adjusting mechanism which permits the relatively angular position of its input shaft and output shaft to be adjusted freely;
• and
• the rotating angular position adjusting mechanism comprises an input gear fixed to the input shaft, an output gear fixed to the output shaft, a rotatable internal gear of a relatively large diameter surrounding the input and output gears, a rotatable input side power transmission gear in mesh with the input gear and the internal gear, a rotatable output side power transmission gear in mesh with the output gear and the internal gear, and a changing mechanism for changing the angular position of at least one of the input side power transmission gear and the output side power transmission gear around the input gear or the output gear.

A compression molding apparatus comprising

• a rotary compression molding means including a rotating supporting member mounted rotatably about its central axis, a plurality of molding die means mounted on said rotating supporting member at circumferentially spaced intervals, each of said molding die means having an upper die assembly and a lower die assembly cooperating with each other, at least one of the upper die assemblies and one of the lower die assemblies being freely movable with respect to the other, a driving source for rotating said rotating supporting member in a predetermined direction and moving said molding die means through a circular conveying passage including a material charging zone, a molding zone, a cooling zone and an article discharging zone located successively, and a die opening-closing means for moving at least one of said upper and lower die assemblies in a predetermined manner with respect to the other according to the movement of said molding die means;
• a material feed means for feeding a plastic material to said molding die means in said material charging means;
• and
• an article carrying means for carrying the molded article from the molding die means in said article discharging zone,
• wherein the material feed means includes an extruding means for extruding a molten plastic material through an extrusion opening and cutting means for cutting the plastic material extruded through the extrusion opening and feeding it to the molding die means;
• the extruding means includes a die head having a flow passage extending from the inlet of an extruder to the extrusion opening existing on its surface and a conduit means for connecting the outlet of the extruder to the inlet of the die head;
• the cutting means includes a rotating shaft extending from behind the die head forwardly beyond the surface of the die head on which the extrusion opening exists, a rotating cutting blade mounted in the forward end portion of the rotating shaft and disposed on said surface of the die head, a driving source and a drivingly connecting means for drivingly connecting the driving source to the rotating shaft;
• and
• at least the die head in the extruding means and at least the rotating shaft and the rotating cutting blade in the cutting means are mounted on a slidable supporting frame, and the supporting frame is provided for free sliding between an operating position at which the die head and the rotating cutting blade are positioned in the material charging zone and a non-operating position at which they are retracted from the operating position.