EP0336806A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Simultaneous extrusion of a dual-layer buffer tube
Assignee: Alcatel Lucent NV
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Filing: 1989-03-20
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Granted: —
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Expires: 2009-03-20
Abstract
Abstract An apparatus and process is provided which enables the simultaneous extrusion of two dissimilar materials into an improved multi-layer buffer tube. Such buffer tubes are typically used to house the optical fibers of a fiber-optic communication cable. The apparatus of the present invention includes a single crosshead assembly for simultaneously forming the plural layers of the buffer tube. As the layers are formed about optical fibers drawn through the crosshead assembly, a thixotropic material is injected into the core of the tube.
Inventors
- 👤 Michael W. Fleck
- 👤 Michael E. Mcguire
- 👤 Randy Schneider
- 👤 Kenneth Cornelison
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 22:36
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4429; G02B6/443; G02B6/4432; B; B29; B29C; B29C48/00; B29C48/03; B29C48/05; B29C48/09; B29C48/15; B29C48/156; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/32; B29C48/335; B29C48/336; B29C48/337; B29C48/34; B29C48/92; G02B6/4479; G02B6/4486; B29C2948/00; B29C2948/92; B29C2948/92504; B29C2948/92514; B29C2948/9258; B29C2948/926; B29C2948/92609; B29C2948/92647; B29C2948/92704; B29C2948/92819; B29C2948/92857; B29C2948/92904; B29C48/06
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
91 words
An apparatus for extruding two dissimilar materials into a buffer tube configuration comprising: means for providing a supply of a first thermoplastic material in a molten state to a single crosshead assembly means; means for separately providing a supply of a second dissimilar thermoplastic material in a molten state to said single crosshead assembly means; and means for controlling said single crosshead assembly means to combine said first and second dissimilar materials into a buffer tube configuration composed of two distinct concentric layers which are in intimate contact with one another.
Claim 2
Independent Claim
91 words
An apparatus for extruding two dissimilar materials into a buffer tube configuration comprising: means for providing a supply of a first thermoplastic material in a molten state to a single crosshead assembly means; means for separately providing a supply of a second dissimilar thermoplastic material in a molten state to said single crosshead assembly means; and means for controlling said single crosshead assembly means to combine said first and second dissimilar materials into a buffer tube configuration composed of two distinct concentric layers which are in intimate contact with one another.
Claim 3
Dependent Claim
19 words
Apparatus according to claim 1, further comprising: means for injecting an amount of filling material into said buffer tube.
Claim 4
Dependent Claim
13 words
Apparatus according to claim 2, wherein said filling material is a thixotropic material.
Claim 5
Dependent Claim
26 words
Apparatus according to claim 2, further comprising means for receiving a length of an optical fiber such that said buffer tube configuration surrounds said optical fiber.
Claim 6
Dependent Claim
38 words
Apparatus according to claim 4, wherein the length of the optical fiber received, and the amount of filling material injected are simultaneously regulated by said means for controlling during said combining of the first and second dissimilar materials.
Claim 7
Dependent Claim
15 words
Apparatus according to claim 4, wherein said buffer tube surrounds a plurality of optical fibers.
Claim 8
Dependent Claim
18 words
Apparatus according to claim 1, wherein said first material is polybutylene terepthalate and said second material is polyamide.
Claim 9
Dependent Claim
14 words
Apparatus according to claim 1, wherein said buffer tube size ranges from 1-4 mm.
Claim 10
Dependent Claim
75 words
Process for extruding two dissimilar materials into a buffer tube configuration comprising the steps of: supplying a first material in a molten state to a single crosshead assembly means; supplying a second, dissimilar material in a molten state to said single crosshead assembly means; and, combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact.
Claim 11
Dependent Claim
75 words
Process for extruding two dissimilar materials into a buffer tube configuration comprising the steps of: supplying a first material in a molten state to a single crosshead assembly means; supplying a second, dissimilar material in a molten state to said single crosshead assembly means; and, combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact.
Claim 12
Dependent Claim
96 words
Process for extruding two dissimilar materials into a buffer tube configuration comprising the steps of: controlling a supply of a first material in a molten state to a single crosshead assembly; controlling a supply of a second, material in a molten state to said single crosshead assembly; combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact; and, injecting a thixotropic material into said buffer tube, wherein said steps controlling, combining and injecting are performed simultaneously.
Claim 13
Dependent Claim
96 words
Process for extruding two dissimilar materials into a buffer tube configuration comprising the steps of: controlling a supply of a first material in a molten state to a single crosshead assembly; controlling a supply of a second, material in a molten state to said single crosshead assembly; combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact; and, injecting a thixotropic material into said buffer tube, wherein said steps controlling, combining and injecting are performed simultaneously.
Claim 14
Dependent Claim
18 words
The process of claim 10, further comprising a step of selecting first and second materials having different viscosities.
Claim 15
Dependent Claim
23 words
The process of claim 10, wherein said step of combining further comprises simultaneously injecting an amount of thixotropic material into said buffer tube.
Claim 16
Dependent Claim
34 words
The process of claim 12, wherein said step of combining further comprises simultaneously inputting a length of optical fiber into said crosshead assembly, whereby said buffer tube configuration is formed around said optical fibers.
Claim 17
Dependent Claim
83 words
A product produced by a process for extruding two dissimilar materials into a buffer tube configuration, wherein said process comprises the steps of: supplying a first material in a molten state of a single crosshead assembly means; supplying a second, dissimilar material in a molten state to said single crosshead assembly means; and, combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact.
Claim 18
Dependent Claim
83 words
A product produced by a process for extruding two dissimilar materials into a buffer tube configuration, wherein said process comprises the steps of: supplying a first material in a molten state of a single crosshead assembly means; supplying a second, dissimilar material in a molten state to said single crosshead assembly means; and, combining said first and second material in said single crosshead assembly into a buffer tube configuration composed of two distinct concentric layers, wherein said two layers are in intimate contact.
Claim 19
Dependent Claim
123 words
A single crosshead assembly means for extruding two dissimilar materials into a buffer tube configuration comprising: a first input port for receiving a first thermoplastic material in a molten state; a second input port for receiving a second dissimilar thermoplastic material in a molten state, said first input port and said second input port being connected to first and second annular flow paths, respectively; and, a single output port, whereby said first and second materials are brought into intimate contact within said single crosshead assembly, for concurrent extrusion through said single output port so as to form a dual layer buffer tube, with one layer of said tube being formed of said first material, and another layer being formed of said second material.
Claim 20
Dependent Claim
123 words
A single crosshead assembly means for extruding two dissimilar materials into a buffer tube configuration comprising: a first input port for receiving a first thermoplastic material in a molten state; a second input port for receiving a second dissimilar thermoplastic material in a molten state, said first input port and said second input port being connected to first and second annular flow paths, respectively; and, a single output port, whereby said first and second materials are brought into intimate contact within said single crosshead assembly, for concurrent extrusion through said single output port so as to form a dual layer buffer tube, with one layer of said tube being formed of said first material, and another layer being formed of said second material.
Claim 21
Dependent Claim
52 words
A single crosshead assembly means according to claim 15, wherein said first and second flow paths further comprise annular cavities at an end close to said input ports for storing an initial amount of said first and second materials respectively, whereby a back pressure is created in said first and second flowpaths.
Claim 22
Dependent Claim
41 words
A single crosshead assembly means according to claim 16, wherein the relative size of said first flow path to said second flow path is approximately proportional to the relative viscosity of the materials injected into said first and second flow paths.
Claim 23
Dependent Claim
47 words
A single crosshead assembly means according to claim 16, further comprising control means whereby the relative thicknesses of said dual layers is controlled by simultaneously regulating both a rate at which the buffer tube is extruded and the back pressure in said first and second flow paths.
References Cited (Backward Citations)
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