Optical unit for fiber optic cables

• US 6,035,087 A
• Filed: 03/09/1998
• Issued: 03/07/2000
• Est. Priority Date: 03/10/1997
• Status: Expired due to Term

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Tatat, Olivier, Bonicel, Jean-Pierre, Elisson, Peter, Gunnarsson, Magnus
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/037,057
• Time in Patent Office: 729 Days
• Field of Search: 385/109, 385/110, 385/111, 385/112, 385/113, 385/114
• US Class Current: 385/109
• CPC Class Codes: G02B 6/441 built up from sub-bundles G02B6/4429, G02B6/4439, G02B6/4479 take precedence

Abstract

An optical unit (5a, 5b) comprising a plurality of optical fibers (2) grouped together in a tube (3a, 3b) and optionally assembled into one or more ribbons inside tube. The tube (3a, 3b) has a Young'"'"'s modulus less than 200 MPa and a Shore A hardness less than 90 at a temperature of approximately +20° C. and a Young'"'"'s modulus less than 2000 MPa at a temperature of approximately -40° C. A fiber optic cable (10, 20) comprising at least one such optical unit (5a, 5b). Application of the cable to telecommunications.

Claims

1. An optical unit (5a, 5b) for a fiber optic cable (10, 20), said unit comprising a plurality of optical fibers (2) grouped in a tube (3a, 3b), characterized in that the tube has a Young'"'"'s modulus less than 200 MPa and a Shore A hardness less than 90 at a temperature of approximately +20°

C. and a Young'"'"'s modulus less than 2000 MPa at a temperature of approximately -40°

C.

2. An optical unit according to claim 1 wherein the optical fibers are assembled in one or more ribbons (9, 11) inside the tube (3b).

3. An optical unit according to claim 1 wherein the tube is made from a thermoplastics material.

4. An optical unit according to claim 3 wherein the tube is made from plasticized polyvinylchloride.

5. An optical unit according to claim 1 wherein the tube is made from an elastomer.

6. An optical unit according to claim 1 wherein the optical fibers are at a distance from the tube in the range 0 to 0.1 mm.

7. A Unitube®

type structure cable comprising an optical unit according to any claim 1.

8. A stranded loose tube type structure cable comprising an optical unit according to claim 6.

9. A telecommunication cable according to claim 7.