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US4772435A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of sheathing a fiber optic

Assignee: Maillefer SA
•
Filing: 1985-12-03
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Granted: 1988-09-20
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Expires: 2005-12-03
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Abstract

Abstract The optical fiber paid out from a reel passes through an extrusion head, then through a cooling vat, the sheath extruded around it being pulled by a withdrawal device. The sheath then passes through a second vat, when the stranding element is withdrawn by an auxiliary withdrawal device under as low a tension as possible. In the second vat, the stranding element is reduced to a temperature lower than the ambient temperature so that contraction of the sheath ensures the excess length of the optical fiber.

Inventors

  • 👤 Rene Schlaeppi
  • 👤 Remy Bruggmann

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 07:34
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4479; G02B6/4484; B; B29; B29C; B29C48/00; B29C48/03; B29C48/05

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 182 words
A method of producing a fiber optic stranding element, including the steps of passing a light-waveguide component through an extrusion head, forming in said extrusion head a protective sheath loosely encompassing said light-waveguide component and cooling said sheath, wherein the improvement comprises the steps of: pulling the sheath and the light-waveguide component together through the extrusion head and through a first cooling means while subjecting the light-waveguide component to a predetermined tensile stress; cooling the sheath and the light-waveguide component to a first temperature in said first cooling means; pulling said sheath and said light-waveguide component together from the first cooling means and passing them directly into and through a second cooling means while subjecting the sheath to a tensile stress as low as possible; maintaining the light-waveguide component free of tensile stress; cooling said sheath and said light-waveguide component in said second cooling means to a second temperature lower than said first temperature, thus enabling said sheath to shorten with respect to said light-waveguide component; and continuously taking up said fiber optic stranding element while pulling from said second cooling means.
Claim 2
Independent Claim 182 words
A method of producing a fiber optic stranding element, including the steps of passing a light-waveguide component through an extrusion head, forming in said extrusion head a protective sheath loosely encompassing said light-waveguide component and cooling said sheath, wherein the improvement comprises the steps of: pulling the sheath and the light-waveguide component together through the extrusion head and through a first cooling means while subjecting the light-waveguide component to a predetermined tensile stress; cooling the sheath and the light-waveguide component to a first temperature in said first cooling means; pulling said sheath and said light-waveguide component together from the first cooling means and passing them directly into and through a second cooling means while subjecting the sheath to a tensile stress as low as possible; maintaining the light-waveguide component free of tensile stress; cooling said sheath and said light-waveguide component in said second cooling means to a second temperature lower than said first temperature, thus enabling said sheath to shorten with respect to said light-waveguide component; and continuously taking up said fiber optic stranding element while pulling from said second cooling means.
Claim 3
Dependent Claim 24 words
The method of claim 1, wherein the cooling in the first cooling means is continued until a predetermined state of temperature equilibrium is attained.
Claim 4
Dependent Claim 48 words
The method of claim 1, wherein the cooling in the second cooling means is carried out in such a way as to cool the sheath to a temperature lower than the ambient temperature and lower than the temperature at which the finished stranding element is to be stored.
Claim 5
Dependent Claim 49 words
The method of claim 1, comprising the step of subjecting the light-waveguide component within the extrusion head and during the first stage of cooling to a degree of tensile stress sufficient to maintain the light-waveguide component taut within the sheath while keeping the elongation thereof within the elastic limit.
Claim 6
Dependent Claim 15 words
The method of claim 4, wherein the elongation of the light-waveguide component is substantially nil.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-09-20 1992-03-21 1992-09-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-09-20 1996-03-21 1996-09-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-09-20 2000-03-21 2000-09-20 $7700.00 Window Closed / Lapsed

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