Apparatus for extruding a continuous coating about a strand

Claim 2

Apparatus for extruding a coating of plastic material about a moving strand, comprising a die head assembly which receives the plastic material, said head having a first cavity which receives and discharges said plastic material, a generally longitudinally extending core member coaxially extending into the first cavity for substantially its entire length and spaced generally uniformly about its periphery from the surrounding walls of the cavity, for defining the passageway for the flow of plastic material between the walls of the first cavity and the outer peripheral surface of the core, said passageway having a relatively thin depth so as to maintain a thin cross-section of material flow, a wall disposed at an angle to the axis of said first cavity and interrupting the flow of material from the first cavity and diverting the flow into the direction of strand movement, a finger extending from said wall with its longitudinal axis substantially aligned with the axis of said strand and having a generally conical portion, said finger being received within a mating cavity defined by tapered walls, the surface of said finger abutting the walls of said cavity and said tapered walls surrounding a strand discharge opening, a plurality of spaced separate passageways defined by said finger and said tapered walls and communicating with said first cavity and the strand discharge opening, and a die mounted on said head and positioned coaxially to said discharge opening.

Claim 3

Apparatus as in claim 1, wherein said slanted wall is positioned about 45* to the axis of plastic flow from said cavity for diverting the plastic flow about 90*.

Claim 4

Apparatus as in claim 2, wherein said slanted wall is part of a plug slideably positioned within an opening extending into said head from one end, said slanted wall cooperating wIth a mating wall of said finger, said plug and said finger having strand receiving openings axially aligned through which said strand passes.

Claim 5

Apparatus as in claim 1, wherein said finger has a plurality of longitudinally extending flutes about its periphery forming said spaced passageways, said flutes varying uniformly in depth with the greater depth being adjacent the exit of the first cavity.

Claim 6

Apparatus as in claim 1, wherein said finger has a strand receiving passageway coaxially passing therethrough and axially aligned and communicating with the strand discharge opening.

Claim 7

Apparatus as in claim 1, wherein said passageways vary in depth with the greater depth being adjacent the discharge of said first cavity.

Claim 8

Apparatus for extruding a thin uniform coating of plastic material about a moving strand, comprising a die head assembly which receives the plastic material, said head having a first cavity with an entrance which receives said plastic material and an exit from which the plastic material leaves, a wall adjacent the exit of said first cavity disposed at an angle to the axis of said first cavity and interrupting said flow of material and diverting the flow into the direction of strand movement, a finger abutting said wall with its longitudinal axis substantially aligned with the axis of said strand and having a generally conical portion, said finger being received within a second cavity defined by a tapered wall, the surface of said finger engaging the wall of said second cavity, said second cavity wall surrounding a strand discharge opening, a plurality of spaced separate passageways defined by said finger and said tapered wall of said second cavity and communicating with said first cavity and the strand discharge opening, said passageways providing the only path for the flow of plastic material between said first cavity and said strand discharge opening, said finger having a strand receiving passageway coaxially passing therethrough and axially aligned and communicating with the strand discharge opening, the plastic material leaving the spaced passageways at the strand discharge opening being at a pressure to force plastic material to flow back into said strand receiving passageway a predetermined distance responsive to the pressure of the plastic material and the lineal speed of the strand, and a die mounted on said head and positioned coaxially to said discharge opening.

Claim 9

Apparatus for extruding a thin uniform coating of plastic material about a moving strand, comprising a die head assembly which receives the plastic material, said head having a first cavity with an entrance which receives said plastic material and an exit from which the plastic material leaves, a wall adjacent the exit of said first cavity disposed at an angle to the axis of said first cavity and interrupting said flow of material and diverting the flow into the direction of strand movement, a finger abutting said wall with its longitudinal axis substantially aligned with the axis of said strand and having a generally conical portion, said finger being received within a second cavity defined by a tapered wall, the surface of said finger engaging the wall of said second cavity, said second cavity wall surrounding a strand discharge opening, a plurality of spaced separate passageways defined by said finger and said tapered wall of said second cavity and communicating with said first cavity and the strand discharge opening, said passageways providing the only path for the flow of plastic material between said first cavity and said strand discharge opening, said finger having a strand receiving passageway coaxially passing therethrough and axially aligned and communicating with the strand discharge opening, the plastic material leaving the spaced passageways at the strand discharge opening being at a pressure to force plastic material to flow back into said strand receiving passageway a predetermined distance responsive to the pressure of the plastic material and the lineal speed of the strand, and a die mounted on said head and positioned coaxially to said discharge opening.

Claim 10

Apparatus for extruding a thin uniform coating of plastic material about a moving strand, comprising a die head assembly which receives the plastic material, said head having a first cavity with an entrance which receives said plastic material and an exit from which the plastic material leaves, a first wall disposed at an angle to the longitudinal axis of said first cavity and interrupting said flow of material and diverting the flow into the direction of strand movement, said wall having a portion contiguous to said first cavity, a finger abutting said first wall with its longitudinal axis substantially aligned with the axis of said strand and having a generally conical portion, said conical portion of said finger being received within a second cavity defined by a tapered wall, the first cavity and said first wall, the finger conical portion engaging the tapered wall of said second cavity, said tapered second cavity wall surrounding a strand discharge opening, a plurality of spaced separate passageways defined by said finger and said tapered wall of said second cavity and communicating with said first cavity and the strand discharge opening, the other end of said first wall being contiguous to one end of certain of said passageways, the corresponding end of the other of said passageways being contiguous to the exit of said first cavity, said passageways providing the only path for the flow of plastic material between said first cavity and said strand discharge opening, said passageways varying uniformly in depth, with the greater depth being adjacent the exit of the first cavitY, and a die mounted on said head and positioned coaxially to said discharge opening.

Claim 11

Apparatus for extruding a thin uniform coating of plastic material about a moving strand, comprising a die head assembly which receives the plastic material, said head having a first cavity with an entrance which receives said plastic material and an exit from which the plastic material leaves, a first wall disposed at an angle to the longitudinal axis of said first cavity and interrupting said flow of material and diverting the flow into the direction of strand movement, said wall having a portion contiguous to said first cavity, a finger abutting said first wall with its longitudinal axis substantially aligned with the axis of said strand and having a generally conical portion, said conical portion of said finger being received within a second cavity defined by a tapered wall, the first cavity and said first wall, the finger conical portion engaging the tapered wall of said second cavity, said tapered second cavity wall surrounding a strand discharge opening, a plurality of spaced separate passageways defined by said finger and said tapered wall of said second cavity and communicating with said first cavity and the strand discharge opening, the other end of said first wall being contiguous to one end of certain of said passageways, the corresponding end of the other of said passageways being contiguous to the exit of said first cavity, said passageways providing the only path for the flow of plastic material between said first cavity and said strand discharge opening, said passageways varying uniformly in depth, with the greater depth being adjacent the exit of the first cavitY, and a die mounted on said head and positioned coaxially to said discharge opening.

Claim 12

Apparatus as in claim 8 wherein said passageways are equally spaced about the periphery of said finger.

Claim 13

Apparatus as in claim 8 further including a core member extending into the first cavity and spaced generally uniformly about its periphery from the surrounding walls of the first cavity.