US4913863A — Split extrusion die assembly for thermoplastic ma…

Claim 1

Independent Claim 163 words

A die spool for extrusion of thermoplastic materials comprising: an axially elongate spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along a longitudinal plane; said first and second spool segments including means for collectively defining an extrusion cavity extending axially between opposing ends of said spool body; said spool body including boss means at one of said ends, and means defining a recess at the other of said ends, said boss means and said recess defining means for respectively mateably engaging boss means and recess defining means of other die spools so as to form a die spool assembly comprised of a number of individual die spools; and alignment means associated with said die spool for ensuring that said defined extrusion cavity is exactly aligned with respective extrusion cavities of said other die spools when said first mentioned die spool is mateably engaged therewith to form said die spool assembly.

Claim 2

Dependent Claim 163 words

A die spool for extrusion of thermoplastic materials comprising: an axially elongate spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along a longitudinal plane; said first and second spool segments including means for collectively defining an extrusion cavity extending axially between opposing ends of said spool body; said spool body including boss means at one of said ends, and means defining a recess at the other of said ends, said boss means and said recess defining means for respectively mateably engaging boss means and recess defining means of other die spools so as to form a die spool assembly comprised of a number of individual die spools; and alignment means associated with said die spool for ensuring that said defined extrusion cavity is exactly aligned with respective extrusion cavities of said other die spools when said first mentioned die spool is mateably engaged therewith to form said die spool assembly.

Claim 3

Dependent Claim 67 words

A die spool as in claim 1, wherein said alignment means includes means, asymmetrically disposed relative to a predetermined longitudinal plane through said die spool, for establishing a single orientation of said first mentioned die spool relative to said other die spools, whereby exact alignment between said extrusion cavity of said first mentioned die spool and said respective extrusion cavities of said other die spools is ensured.

Claim 4

Dependent Claim 22 words

A die spool as in claim 2, wherein each of said boss means and said recess defining means includes said alignment means.

Claim 5

Dependent Claim 56 words

A die spool as in claim 2, wherein said orientation establishing means includes a plurality of apertures defined in said boss means and said recess defining means, and a corresponding number of pins receivable in said apertures of said first mentioned die spool and in said apertures of said other die spools when mateably engaged therewith.

Claim 6

Dependent Claim 28 words

A die spool as in claim 1, further comprising temperature control means in heat exchange relationship with said spool body for effecting temperature control of said extrusion cavity.

Claim 7

Dependent Claim 18 words

A die spool as in claim 5, wherein said temperature control means includes an electrical resistance heater means.

Claim 8

Dependent Claim 48 words

A die spool as in claim 1, further comprising a pair of mounting flanges each located at a respective said opposing end of said die spool and defining a substantially planar engagement face for mating with an engagement face of a mounting flange associated with other die spools.

Claim 9

Dependent Claim 64 words

A die spool as in claim 7, wherein said mounting flanges include means defining a beveled edge which, in cross-section, diverges downwardly away from said planar engagement face for cooperation with a clamping structure to assist in drawing said engagement face of said first mentioned die spool and said engagement face,;of a mounting flange of said other die spools into closely adjacent mated relationship.

Claim 10

Dependent Claim 61 words

A die spool as in claim 1, wherein said spool body defines a recessed surface which extends at least partially around an exterior circumference of said spool body, said die spool further including heater means disposed within said recessed surface in heat-exchange relationship with said die spool, whereby temperature control of the thermoplastic material within said extrusion cavity may be effected.

Claim 11

Dependent Claim 16 words

A die spool as in claim 9, wherein said heater means includes an electrical resistance heater.

Claim 12

Dependent Claim 180 words

A die spool assembly for extrusion of thermoplastic materials comprising plural die spools coaxially coupled to one another so as to define an extrusion axis, each said die spool including: an elongate spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along a longitudinal plane which intercepts said extrusion axis, said first and second spool segments thereby collectively establishing said spool body; said first and second spool segments also collectively including means defining an extrusion cavity extending along said extrusion axis between opposing ends of said spool body; said spool body including boss means at one of said ends, and means defining a recess at the other of said ends, said boss means and recess defining means for respectively mateably engaging said boss means and said recess defining means of another die spool in said assembly; and alignment means for ensuring that said defined extrusion cavity of said die spool is exactly aligned with said extrusion cavity of said another die spool in said assembly mateably engaged therewith.

Claim 13

Dependent Claim 180 words

A die spool assembly for extrusion of thermoplastic materials comprising plural die spools coaxially coupled to one another so as to define an extrusion axis, each said die spool including: an elongate spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along a longitudinal plane which intercepts said extrusion axis, said first and second spool segments thereby collectively establishing said spool body; said first and second spool segments also collectively including means defining an extrusion cavity extending along said extrusion axis between opposing ends of said spool body; said spool body including boss means at one of said ends, and means defining a recess at the other of said ends, said boss means and recess defining means for respectively mateably engaging said boss means and said recess defining means of another die spool in said assembly; and alignment means for ensuring that said defined extrusion cavity of said die spool is exactly aligned with said extrusion cavity of said another die spool in said assembly mateably engaged therewith.

Claim 14

Dependent Claim 68 words

A die spool assembly as in claim 11, wherein said alignment means includes means, asymmetrically disposed relative to a predetermined longitudinal plane through said die spool, for establishing a single orientation of said first mentioned die spool relative to said another die spool, whereby exact alignment between said extrusion cavity of said first mentioned die spool and said respective extrusion cavity of said another die spool is ensured.

Claim 15

Dependent Claim 22 words

A die spool assembly as in claim 12, wherein said boss means and said recess defining means each includes said alignment means.

Claim 16

Dependent Claim 26 words

A die spool assembly as in claim 13, wherein said boss means and said recess defining means are each coaxially disposed relative to said extrusion axis.

Claim 17

Dependent Claim 55 words

A die spool assembly as in claim 12, wherein said alignment means includes a plurality of apertures defined in said boss means and said recess defining means, and a corresponding number of pins received in said apertures of said first mentioned die spool and in said apertures of said another die spool mateably engaged therewith.

Claim 18

Dependent Claim 55 words

A die spool assembly as in claim 11, wherein each said die spool further comprises a pair of mounting flanges each located at a respective said opposing end of said die spool and defining a substantially planar engagement face for mating with an engagement face of a mounting flange associated with said another die spool.

Claim 19

Dependent Claim 84 words

A die spool assembly as in claim 16, wherein said mounting flanges include means defining a beveled edge which, in cross-section, diverges downwardly away from said planar engagement face, and wherein said assembly further comprises clamping means defining surfaces which cooperate with said beveled edge of said first mentioned die spool and with a beveled edge of said another die spool to assist in drawing said engagement faces of said first mentioned and another die spools into closely adjacent mated relationship with one another.

Claim 20

Dependent Claim 73 words

A die spool assembly as in claim 11, wherein preselected ones of said die spools include a recessed surface which extends at least partially around an exterior circumference of said spool body, said preselected ones of said die spools further including heater means disposed within said recessed surface in heat-exchange relationship with said die spool, whereby temperature control of the thermoplastic material, within said extrusion cavity may be effected along said extrusion axis.

Claim 21

Dependent Claim 17 words

A die spool assembly as in claim 18, wherein said heater means includes an electrical resistance heater.

Claim 22

Dependent Claim 229 words

A thermoplastic extrusion apparatus comprising, in combination: extruder means for fluxing a thermoplastic material and for discharging molten thermoplastic extrudate through a discharge end thereof; and a die spool assembly having an inlet end coupled to said discharge end for receiving said thermoplastic extrudate from said extruder means, and an outlet end opposite to said inlet end thereof, said die spool assembly between said inlet and outlet ends establishing an extrusion cavity oriented along an extrusion axis; said die spool assembly including a plurality of die spools coupled one to another coaxially relative to said extrusion axis, wherein each said die spool of said die spool assembly comprises an elongate spool body including means which allow separation of said spool body into first and second spool segments which are mateable with one another along a longitudinal plane which intercepts said extrusion axis, said first and second spool segments thereby collectively establishing said spool body; and wherein, said die spool assembly further comprises temperature control means in heat exchange relationship with at least preselected ones of said die spools for establishing a decreasing temperature gradient between said inlet and discharge ends thereof within said extrusion cavity of said die spool assembly through which said thermoplastic extrudate is conveyed, thereby to at least partially solidify said thermoplastic extrudate upon its being discharged from said outlet end of said die spool assembly.

Claim 23

Dependent Claim 229 words

A thermoplastic extrusion apparatus comprising, in combination: extruder means for fluxing a thermoplastic material and for discharging molten thermoplastic extrudate through a discharge end thereof; and a die spool assembly having an inlet end coupled to said discharge end for receiving said thermoplastic extrudate from said extruder means, and an outlet end opposite to said inlet end thereof, said die spool assembly between said inlet and outlet ends establishing an extrusion cavity oriented along an extrusion axis; said die spool assembly including a plurality of die spools coupled one to another coaxially relative to said extrusion axis, wherein each said die spool of said die spool assembly comprises an elongate spool body including means which allow separation of said spool body into first and second spool segments which are mateable with one another along a longitudinal plane which intercepts said extrusion axis, said first and second spool segments thereby collectively establishing said spool body; and wherein, said die spool assembly further comprises temperature control means in heat exchange relationship with at least preselected ones of said die spools for establishing a decreasing temperature gradient between said inlet and discharge ends thereof within said extrusion cavity of said die spool assembly through which said thermoplastic extrudate is conveyed, thereby to at least partially solidify said thermoplastic extrudate upon its being discharged from said outlet end of said die spool assembly.

Claim 24

Dependent Claim 38 words

A thermoplastic extrusion apparatus as in claim 20, wherein said first and second spool segments also collectively include means defining a portion of said extrusion cavity extending along said extrusion axis between opposing ends of said spool body.

Claim 25

Dependent Claim 57 words

A thermoplastic extrusion apparatus as in claim 20, wherein said spool body includes boss means at one of said ends, and means defining a recess at the other of said ends, said boss means and recess defining means for respectively mateably engaging said boss means and said recess defining means of another die spool in said assembly.

Claim 26

Dependent Claim 46 words

A thermoplastic extrusion apparatus as in claim 22, wherein each said die spool further comprises alignment means for ensuring that said defined extrusion cavity portion is exactly aligned with said extrusion cavity portion of said another die spool in said assembly which is mateably engaged therewith.

Claim 27

Dependent Claim 68 words

A thermoplastic extrusion apparatus as in claim 23, wherein said alignment means includes means, asymmetrically disposed relative to a predetermined longitudinal plane through said die spool, for establishing a single orientation of said first mentioned die spool relative to said another die spool, whereby exact alignment between said extrusion cavity of said first mentioned die spool and said respective extrusion cavities of said another die spool is ensured.

Claim 28

Dependent Claim 22 words

A thermoplastic extrusion apparatus as in claim 24, wherein said boss means and said recess defining means each includes said alignment means.

Claim 29

Dependent Claim 26 words

A thermoplastic extrusion apparatus as in claim 25, wherein said boss means and said recess defining means are each coaxially disposed relative to said extrusion axis.

Claim 30

Dependent Claim 48 words

A thermoplastic extrusion apparatus as in claim 24, wherein said alignment means includes a plurality of apertures defined in one end of said spool body, and a corresponding number of pins received in said apertures, said pins being mateably engaged with said apertures of said another die spool.

Claim 31

Dependent Claim 55 words

A thermoplastic extrusion apparatus as in claim 20, wherein each said die spool further comprises a pair of mounting flanges each located at a respective said opposing end of said die spool and defining a substantially planar engagement face for mating with an engagement face of a mounting flange associated with said another die spool.

Claim 32

Dependent Claim 84 words

A thermoplastic extrusion apparatus as in claim 28, wherein said mounting flanges include means defining a beveled edge which, in cross-section, diverges downwardly away from said planar engagement face, and wherein said assembly further comprises clamping means defining surfaces which cooperate with said beveled edge of said first mentioned die spool and with a beveled edge of said another die spool to assist in drawing said engagement faces of said first mentioned and another die spools into closely adjacent mated relationship with one another.

Claim 33

Dependent Claim 80 words

A thermoplastic extrusion apparatus as in claim 20, wherein said temperature control means is comprised by preselected ones of said die spools including a recessed surface which extends at least partially around an exterior circumference of said spool body, said preselected ones of said die spools further including heater means disposed within said recessed surface in heat-exchange relationship with said die spool, whereby temperature control of the thermoplastic material within said extrusion cavity may be effected along said extrusion axis.

Claim 34

Dependent Claim 17 words

A thermoplastic extrusion apparatus as in claim 30, wherein said heater means includes an electrical resistance heater.

Claim 35

Dependent Claim 28 words

A thermoplastic extrusion apparatus as in claim 20, further comprising means downstream of said outlet end of said die spool assembly for cooling, and thus solidifying, said extrudate.

Claim 36

Dependent Claim 52 words

A thermoplastic extrusion apparatus as in claim 32, further comprising means, downstream of said cooling and solidifying means for frictionally engaging said solidified extrudate and conveying the same along said extrusion axis and to thereby assist in the conveyance of said thermoplastic extrudate through said extrusion cavity of said die spool assembly.

Claim 37

Independent Claim 298 words

A method of forming extruded thermoplastic products comprising the steps of: (a) extruding a molten thermoplastic material through an extrusion die so as to form a product preform having a preselected cross-sectional geometry; (b) supporting a length of said product preform on a portion of an extrusion cavity defined by a lower segment of a die spool by coupling said lower die spool segment to said extrusion die; (c) positioning a remaining portion of said extrusion cavity defined by an upper segment of said die spool in mated relationship with said first mentioned portion of said lower die spool segment, by bringing said upper and lower die spool segments into mated relationship with one another while said product preform length is being supported by said lower spool segment; and then (d) effecting temperature control of said product preform within said extrusion cavity collectively established by said mated upper and lower die spool segments by controlling temperature within said extrusion cavity through which said product preform is conveyed, wherein step (a) is practiced continually so as to allow said length of product preform to increase by being conveyed beyond a downstream end of said die spool, and wherein the method further comprises the steps of; (e) supporting said increased length of said product preform on a portion of an extrusion cavity defined by a lower segment of a second die spool by coupling said second lower die spool segment to said first mentioned lower die spool segment; and then (f) positioning a remaining portion of said extrusion cavity defined by an upper segment of said second die spool in mated relationship with said extrusion cavity portion of said second lower die spool segment, by bringing said second upper and lower die spool segments into mated relationship with one another.

Claim 38

Independent Claim 298 words

A method of forming extruded thermoplastic products comprising the steps of: (a) extruding a molten thermoplastic material through an extrusion die so as to form a product preform having a preselected cross-sectional geometry; (b) supporting a length of said product preform on a portion of an extrusion cavity defined by a lower segment of a die spool by coupling said lower die spool segment to said extrusion die; (c) positioning a remaining portion of said extrusion cavity defined by an upper segment of said die spool in mated relationship with said first mentioned portion of said lower die spool segment, by bringing said upper and lower die spool segments into mated relationship with one another while said product preform length is being supported by said lower spool segment; and then (d) effecting temperature control of said product preform within said extrusion cavity collectively established by said mated upper and lower die spool segments by controlling temperature within said extrusion cavity through which said product preform is conveyed, wherein step (a) is practiced continually so as to allow said length of product preform to increase by being conveyed beyond a downstream end of said die spool, and wherein the method further comprises the steps of; (e) supporting said increased length of said product preform on a portion of an extrusion cavity defined by a lower segment of a second die spool by coupling said second lower die spool segment to said first mentioned lower die spool segment; and then (f) positioning a remaining portion of said extrusion cavity defined by an upper segment of said second die spool in mated relationship with said extrusion cavity portion of said second lower die spool segment, by bringing said second upper and lower die spool segments into mated relationship with one another.

Claim 39

Dependent Claim 28 words

A method as in claim 34, wherein step (d) is practiced by establishing a decreasing temperature gradient within said extrusion cavities of said first and second die spools.

Claim 40

Dependent Claim 25 words

A method as in claim 35, wherein step (d) is practiced by effecting heat exchange relationship between the die spool and a temperature control system.

Claim 41

Dependent Claim 37 words

A method as in claim 36, wherein step (d) is practiced by operating electrical resistive heater means associated with at least one of said first and second die spools in heat exchange relationship with the die spool.

Claim 42

Dependent Claim 20 words

A method as in claim 34, further comprising the step of solidifying said product preform discharged from said die spool.

Claim 43

Dependent Claim 25 words

A method as in claim 38, wherein said step of solidifying said product preform is practiced by passing the same through a cooling fluid bath.

Claim 44

Dependent Claim 34 words

A method as in claim 39, further comprising the step of pulling said cooled and solidified product through said bath to thereby assist in the conveyance of said product preform through said extrusion cavity.

Claim 45

Dependent Claim 123 words

A die spool assembly for extrusion of thermoplastic material along a predetermined extrusion axis and adapted to being coupled operatively to a discharge end of an extruder, said die spool assembly comprising a number of die spools coaxially coupled end-to-end along said extrusion axis, wherein each said die spool includes: an elongate die spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along said extrusion axis; said first and second die segments collectively including means defining an extrusion cavity for shaping said thermoplastic material; and coupling means associated with said spool body for mateably coupling said die spool end-to-end along said extrusion axis with another said die spool in said assembly.

Claim 46

Dependent Claim 123 words

A die spool assembly for extrusion of thermoplastic material along a predetermined extrusion axis and adapted to being coupled operatively to a discharge end of an extruder, said die spool assembly comprising a number of die spools coaxially coupled end-to-end along said extrusion axis, wherein each said die spool includes: an elongate die spool body including means which allow separation of said spool body into first and second spool segments mateable with one another along said extrusion axis; said first and second die segments collectively including means defining an extrusion cavity for shaping said thermoplastic material; and coupling means associated with said spool body for mateably coupling said die spool end-to-end along said extrusion axis with another said die spool in said assembly.

Claim 47

Dependent Claim 66 words

A die spool assembly as in claim 42, wherein said coupling means includes; boss means at one end of said die spool; and means defining a recess at an opposite end of said die spool; said boss means and said recess defining means for respectively mateably engaging said boss means and said recess defining means of said another die spool in said assembly mateably coupled therewith.

Claim 48

Dependent Claim 41 words

A die spool assembly as in claim 42, further comprising alignment means for ensuring that said defined extrusion cavity of said die spool is properly aligned with said extrusion cavity of said another die spool in said assembly mateably coupled therewith.

Claim 49

Dependent Claim 67 words

A die spool assembly as in claim 43, wherein said alignment means includes means, asymmetrically disposed relative to a predetermined longitudinal plane through said die spool, for establishing a single orientation of said first mentioned die spool relative to said another die spool, whereby proper alignment of said extrusion cavity of said first mentioned die spool and said extrusion cavity of said another die spool is ensured.

Claim 50

Dependent Claim 54 words

A die spool assembly as in claim 42 or 43, wherein said die spool further comprises a pair of mounting flanges each located at a respective end of said die spool and defining a substantially planar engagement face for mating with an engagement face of a mounting flange associated with said another die spool.

Claim 51

Dependent Claim 31 words

A die spool assembly as in claim 42, wherein at least one of said number of die spools includes temperature control means for effecting temperature control within said extrusion cavity thereof.

Claim 52

Dependent Claim 18 words

A die spool assembly as in claim 46, wherein said temperature control means includes an electrical resistance heater.

Claim 53

Independent Claim 267 words

A method of forming extruded thermoplastic products comprising the steps of: (a) extruding a molten thermoplastic material through an extrusion die so as to form a produce preform having a preselected cross-sectional geometry; (b) supporting a length of said product preform on a portion of an extrusion cavity defined by a lower segment of a die spool by coupling said lower die spool segment to said extrusion die; (c) positioning a remaining portion of said extrusion cavity defined by an upper segment of said die spool in mated relationship with said first mentioned portion of said lower die spool segment, by bringing said upper and lower die spool segments into mated relationship with one another while said product preform length is being supported by said lower spool segment, wherein step (a) is practiced continually so as to allow said length of product preform to increase by being conveyed beyond a downstream end of said die spool, and wherein the method further comprises the steps of; (e) supporting said increased length of said product preform on a portion of an extrusion cavity defined by said portion of an extrusion cavity defined by a lower segment of a second die spool by coupling said second lower die spool segment to said first mentioned lower die spool segment; and then (f) positioning a remaining portion of said extrusion cavity defined by an upper segment of said second die spool in mated relationship with said extrusion cavity portion of said second lower die spool segment, by bringing said second upper and lower die spool segments into mated relationship with one another.

Claim 54

Independent Claim 267 words

A method of forming extruded thermoplastic products comprising the steps of: (a) extruding a molten thermoplastic material through an extrusion die so as to form a produce preform having a preselected cross-sectional geometry; (b) supporting a length of said product preform on a portion of an extrusion cavity defined by a lower segment of a die spool by coupling said lower die spool segment to said extrusion die; (c) positioning a remaining portion of said extrusion cavity defined by an upper segment of said die spool in mated relationship with said first mentioned portion of said lower die spool segment, by bringing said upper and lower die spool segments into mated relationship with one another while said product preform length is being supported by said lower spool segment, wherein step (a) is practiced continually so as to allow said length of product preform to increase by being conveyed beyond a downstream end of said die spool, and wherein the method further comprises the steps of; (e) supporting said increased length of said product preform on a portion of an extrusion cavity defined by said portion of an extrusion cavity defined by a lower segment of a second die spool by coupling said second lower die spool segment to said first mentioned lower die spool segment; and then (f) positioning a remaining portion of said extrusion cavity defined by an upper segment of said second die spool in mated relationship with said extrusion cavity portion of said second lower die spool segment, by bringing said second upper and lower die spool segments into mated relationship with one another.

Claim 55

Dependent Claim 19 words

A method as in claim 48, further comprising the step solidifying said product preform discharged from said die spool.

Claim 56

Dependent Claim 25 words

A method as in claim 49, wherein said step of solidifying said product preform is practiced by passing the same through a cooling fluid bath.

Claim 57

Dependent Claim 22 words

A method as in claim 50, further comprising the step of pulling said cooling and solidified product through said cooling fluid bath.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-04-02	1993-10-02	1994-04-03	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-04-02	1997-10-02	1998-04-03	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-04-02	2001-10-02	2002-04-03	$7700.00	Window Closed / Lapsed

Split extrusion die assembly for thermoplastic materials and methods of using the same

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