Optical waveguides – Optical transmission cable – Loose tube type
Reexamination Certificate
1999-06-18
2001-11-06
Palmer, Phan T. H. (Department: 2877)
Optical waveguides
Optical transmission cable
Loose tube type
Reexamination Certificate
active
06314224
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to optical fiber cables having cable jackets with non-circular cavity cross sections for improved crush resistance.
2. Background Art
The background art shows cable jackets having non-circular cross-sectional shapes for both the outer periphery and cavity thereof. Moreover, the background art associates improved crush resistance with such non-circular shapes.
A paper by Stevens et al., entitled “FINITE ELEMENT MODELING OF OPTIC FIBER CABLE CRUSH PERFORMANCE” (IWCS, November 1998), provides an analysis of elastic-plastic deformations of thermoplastic cable elements using finite element modeling. This paper is incorporated herein by reference. The cable elements considered in the above paper included non-circular cross sections. The authors concluded that by changing the shape from a circular to an elliptical or rectangular cross-section, the cable can have improved crush resistance, lower weight and better unidirectional flexibility.
Blew et al. (U.S. Pat. No. 5,651,081) disclose an optical fiber cable having a non-circular outer periphery and a circular cavity. See, e.g., FIG. 4 of Blew et al.
Cables having a non-circular outer periphery exhibit greatly improved crush performance but may pose cable closure compatibility problems, product marketing and/or customer perception problems as compared to cables having a conventional circular outer periphery.
Dean et al. (U.S. Pat. No. 4,420,220) disclose an optical fiber cable having a circular outer periphery and a non-circular cavity. See, e.g., FIG. 3 of Dean et al. However, in Dean et al., the non-circular cavity is oriented such that its major axis coincides with a line extending between the strength members. Consequently, this fiber cable exhibits relatively poor crush resistance in a direction transverse to the line extending between the strength members.
SUMMARY OF THE INVENTION
It is an object of the invention to maximize the crush resistance of a fiber optic cable by providing a cavity with a non-circular cross section.
The above object is accomplished by providing an optical fiber cable in which the non-circular cross section cavity has a minor axis that is substantially aligned with a line extending between the strength members. The inner cavity may have many different types of non-circular shapes.
If a non-circular outer periphery of the cable does not pose any problems such as described above, then that feature could be combined with the non-circular cavity having the orientation described above, and the non-circular outer periphery should also have a predetermined orientation to compliment the orientation of the non-circular cavity.
REFERENCES:
patent: 4038489 (1977-07-01), Stenson et al.
patent: 4166670 (1979-09-01), Ramsay
patent: 4199225 (1980-04-01), Slaughter et al.
patent: 4312566 (1982-01-01), Jackson
patent: 4420220 (1983-12-01), Dean et al.
patent: 4741594 (1988-05-01), Suzuki
patent: 5067831 (1991-11-01), Robbins et al.
patent: 5155304 (1992-10-01), Gossett et al.
patent: 5222180 (1993-06-01), Kuder et al.
patent: 5333229 (1994-07-01), Sayegh
patent: 5402966 (1995-04-01), Van Hoessle
patent: 5448670 (1995-09-01), Blew et al.
patent: 5509097 (1996-04-01), Tondi-Resta et al.
patent: 5651081 (1997-07-01), Blew et al.
patent: 5675686 (1997-10-01), Rosenmayer et al.
patent: 676 654 (1995-10-01), None
patent: 2 555 764 (1985-05-01), None
patent: 1422147 (1976-01-01), None
patent: 1480206 (1977-07-01), None
Patent Abstracts of Japan, vol. 15, No. 144 (P-1189) (Apr. 1991) as it relates to JP 03-020704 (Jan. 1991).
J. Boyet Stevens et al., “Finite Element Modeling of Optic Fiber Cable Crush Performance”, Alcatel OFCCC. English Abstract of Japanese Patent Application No. 919893; Nov. 1998.
Barker Jeffrey S.
Buckland Eric
Elisson Peter
Stevens John Boyet
Alcatel
Mooney Michael P.
Palmer Phan T. H.
Sughrue Mion Zinn Macpeak & Seas, PLLC
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