Apparatus for manufacturing a grooved cylindrical core particularly for optical cable

Claim 1

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder; a rotating die means having a first extrusion bore for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves therebetween; said first and second extrusion bores of the rotating die means formed within a single rotating integral die; and auxiliary extruder means connected to the main extruder for feeding an extrusion material of a different color from that of said main extruder along a feed path having conduits within the integral body of said die in communication with at least one of said die channels.

Claim 2

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder; a rotating die means having a first extrusion bore for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves therebetween; said first and second extrusion bores of the rotating die means formed within a single rotating integral die; and auxiliary extruder means connected to the main extruder for feeding an extrusion material of a different color from that of said main extruder along a feed path having conduits within the integral body of said die in communication with at least one of said die channels.

Claim 13

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having a stationary extruder head; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; a stationary collar connected to the extruder head; a washer disposed within the collar in sealing contact with the rotating die means and thrust bearing means disposed between said washer and collar, said washer and thrust bearing means transmitting to the stationary collar axial thrust forces exerted by the extrusion material on the rotating die means to minimize leakage of the extrusion material from the rotating die means while reducing die drive torque, and an orifice formed in the extruder head in communication with the washer for draining away from the manufactured cylindrical core extrusion material entering the orifice from between the rotating die means and extruder head, said leaked extrusion material tending to act as a lubricant between said rotating die means and stationary extruder head while also tending to lubricate contact surfaces between said washer, collar and thrust bearing means before passing through said orifice.

Claim 14

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having a stationary extruder head; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; a stationary collar connected to the extruder head; a washer disposed within the collar in sealing contact with the rotating die means and thrust bearing means disposed between said washer and collar, said washer and thrust bearing means transmitting to the stationary collar axial thrust forces exerted by the extrusion material on the rotating die means to minimize leakage of the extrusion material from the rotating die means while reducing die drive torque, and an orifice formed in the extruder head in communication with the washer for draining away from the manufactured cylindrical core extrusion material entering the orifice from between the rotating die means and extruder head, said leaked extrusion material tending to act as a lubricant between said rotating die means and stationary extruder head while also tending to lubricate contact surfaces between said washer, collar and thrust bearing means before passing through said orifice.

Claim 19

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having an extruder head; means for guiding a flow of extrusion material from said main extruder to form the cylindrical core; rotating die means located downstream from said material flow guiding means and including a bore having die channels for forming said peripheral grooves, said rotating die means including a side wall extending generally parallel to a longitudinal die axis in intimate contact with a side wall of said extruder head; a stationary collar connected to the extruder head for mounting the rotating die means thereto; and washer means mounted between the collar and rotating die means for transmitting to the head and through the collar axial thrust forces exerted by the extrusion material on the rotating die means, said washer means including spherical contact surfaces in sealing contact with a spherical shoulder of said rotating die means for preventing leakage of extrusion material from an interface formed between the rotating die means and the head.

Claim 20

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having an extruder head; means for guiding a flow of extrusion material from said main extruder to form the cylindrical core; rotating die means located downstream from said material flow guiding means and including a bore having die channels for forming said peripheral grooves, said rotating die means including a side wall extending generally parallel to a longitudinal die axis in intimate contact with a side wall of said extruder head; a stationary collar connected to the extruder head for mounting the rotating die means thereto; and washer means mounted between the collar and rotating die means for transmitting to the head and through the collar axial thrust forces exerted by the extrusion material on the rotating die means, said washer means including spherical contact surfaces in sealing contact with a spherical shoulder of said rotating die means for preventing leakage of extrusion material from an interface formed between the rotating die means and the head.

Claim 22

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; and driving means rotatable about a longitudinal axis of said die means and slidable along said die axis for selectively engaging with said die means to rotate said die means.

Claim 23

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; and driving means rotatable about a longitudinal axis of said die means and slidable along said die axis for selectively engaging with said die means to rotate said die means.

Claim 29

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having a stationary extruder head; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; a stationary collar connected to the extruder head; a washer disposed within the collar in sealing contact with the rotating die means and thrust bearing means disposed between said washer and collar, said washer and thrust bearing means transmitting to the stationary collar axial thrust forces exerted by the extrusion material on the rotating die means to minimize leakage of the extrusion material from the rotating die means while reducing die drive torque, and an orifice formed in the extruder head in communication with the washer for draining away from the manufactured cylindrical core extrusion material entering the orifice from between the rotating die means and extruder head, said leaked extrusion material tending to act as a lubricant between said rotating die means and stationary extruder head while also tending to lubricate contact surfaces between said washer, collar and thrust bearing means before passing through said orifice; driving means rotatable about a longitudinal axis of said die means and slidable along said die axis for selectively engaging said die means to rotate said die means; and auxiliary extruder means connected to the main extruder for feeding an extrusion material of a different color from that of said main extruder along a feed path having conduits within the integral body of said die in communication with at least one cf said die channels.

Claim 30

A device for manufacturing a cylindrical core having helical peripheral grooves, comprising: a main extruder having a stationary extruder head; a rotating die means connected to receive a flow of extrusion material from said main extruder; said rotating die means having a first extrusion bore rotating about a longitudinal axis thereof for guiding a flow of extrusion material from said main extruder to form the cylindrical core and a second extrusion bore formed with die channels rotatable about a longitudinal axis of the second bore, each channel having a cross section corresponding respectively to the cross section of ribs defining said peripheral grooves between adjacent ribs to form said helical peripheral grooves; a stationary collar connected to the extruder head; a washer disposed within the collar in sealing contact with the rotating die means and thrust bearing means disposed between said washer and collar, said washer and thrust bearing means transmitting to the stationary collar axial thrust forces exerted by the extrusion material on the rotating die means to minimize leakage of the extrusion material from the rotating die means while reducing die drive torque, and an orifice formed in the extruder head in communication with the washer for draining away from the manufactured cylindrical core extrusion material entering the orifice from between the rotating die means and extruder head, said leaked extrusion material tending to act as a lubricant between said rotating die means and stationary extruder head while also tending to lubricate contact surfaces between said washer, collar and thrust bearing means before passing through said orifice; driving means rotatable about a longitudinal axis of said die means and slidable along said die axis for selectively engaging said die means to rotate said die means; and auxiliary extruder means connected to the main extruder for feeding an extrusion material of a different color from that of said main extruder along a feed path having conduits within the integral body of said die in communication with at least one cf said die channels.

Claim 31

A method of manufacturing an optical cable having a cylindrical core formed with helical peripheral grooves adopted to carry optical fibers therein, comprising the steps of: (a) directing a flow of extrusion material into a tapered interior cavity formed between a tapered tube and an extruder head; (b) guiding said flow of extrusion material from said cavity into a first extrusion bore formed within a single rotating die while feeding a strength member through a central hollow region of said tapered tube so that said extrusion material covers said central member to form said cable therewith whereby said cable is reinforced by the central member; (c) feeding said formed cylindrical core from the first extrusion bore into a second extrusion bore formed with die channels within said single die to impart to said cylindrical core a series of circumferentially spaced ribs having a cross section corresponding respectively to the cross section of said die channels; and (d) cooling said grooved cylindrical core after it passes through said single rotating die.

Claim 32

A method of manufacturing an optical cable having a cylindrical core formed with helical peripheral grooves adopted to carry optical fibers therein, comprising the steps of: (a) directing a flow of extrusion material into a tapered interior cavity formed between a tapered tube and an extruder head; (b) guiding said flow of extrusion material from said cavity into a first extrusion bore formed within a single rotating die while feeding a strength member through a central hollow region of said tapered tube so that said extrusion material covers said central member to form said cable therewith whereby said cable is reinforced by the central member; (c) feeding said formed cylindrical core from the first extrusion bore into a second extrusion bore formed with die channels within said single die to impart to said cylindrical core a series of circumferentially spaced ribs having a cross section corresponding respectively to the cross section of said die channels; and (d) cooling said grooved cylindrical core after it passes through said single rotating die.