EXTENSIBLE-RETRACTABLE HELICALLY COILED FIBER OPTIC ASSEMBLY

• US 3,817,595 A
• Filed: 05/15/1972
• Issued: 06/18/1974
• Est. Priority Date: 05/06/1970
• Status: Expired due to Term

• Current Assignee: Vicon Fiber Optics Corp.
• Original Assignee: Alfred E. Edelman, Lionel J. Laplante
• Inventors: Edelman, Alfred E., LaPlante, Lionel J.
• Primary Examiner(s): Fritsch, Daniel J.
• Application Number:
  US05/253,644
• Time in Patent Office: 764 Days
• Field of Search: 156/91,173,196,289,290,291,293,294,296 264/230 174/69 65/4,DIG.7 350/96B
• US Class Current: 385/115
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/4457 Bobbins; Reels
• CPC Class Codes: G02B 6/4458 Coiled, e.g. extensible helix
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina

Abstract

An extensible-retractable helically coiled fiber optic assembly, similar on configuration to the well known helically coiled telephone wire connecting telephone hand-sets to telephone equipment, is provided. A method of making the extensibleretractable coiled fiber optic assembly is taught in which individual glass fibers drawn down to a maximum diameter of 0.001 inches, and preferably down to 0.0008 inches or less, are clamped at their extremities to form a fiber optic bundle. The fiber optic bundle is disposed in a sheath of elastic material having a plastic memory, such as rubber, polyvinyl chloride, etc. This assembly is then wound about a mandrel and held in the coiled position during heat treatment to cure or set the sheathing material in the helical shape. The entire assembly is then cooled at a rate which will maintain the set and will not deleteriously affect the optical fibers.

Claims

1. A method of making an extensible-retractable helically coiled fiber optic assembly, comprising the steps of disposing a bundle of a plurality of flexible optical fibers within a sheath of elastic material having an inner diameter greater than the outer diameter of said bundle of flexible optical fibers so that said plurality of fibers are free to move relative to said sheath, forming the assembled sheath and optical fibers into a helical shape, heating the assembled sheath and optical fibers to a temperature sufficient to set the elastic material and thereafter cooling the elastic sheath and optical fibers at a rate such that the elastic material is set and the optical fibers remain free to move relative to each other and to the elastic sheath, and further including the step of treating said optical fibers anytime prior to the setting of the elastic material to prevent said fibers from sticking together or to the sheath upon heating thereof.

2. A method according to claim 1, wherein the step of disposing said plurality of optical fibers within said sheath of elastic material comprises drawing glass optical fibers down to a diameter equal to or less than 0.001 inches, and forming a bundle of said glass optical fibers.

3. A method according to claim 2, wherein said step of forming a bundle of said glass optical fibers comprises clamping the ends of a plurality of said glass optical fibers together with suitable clamping means, and the step of disposing the plurality of optical fibers within said sheath of elastic material further includes disposing the assembled bundle of glass optical fibers and clamping members within said sheath and affixing the clamping members to the inner wall of the sheath with the portions of the glass optical fibers disposed between said clamping members free to move within said sheath.

4. A method according to claim 2, wherein the step of drawing the glass optical fibers comprises drawing them down to a diameter equal to 0.0008 inches or less.

5. A method according to claim 4, wherein said step of forming a bundle of said glass optical fibers comprises clamping the ends of a plurality of said glass optical fibers together with suitable clamping means, and the step of disposing the plurality of optical fibers within said sheath of elastIc material further includes disposing the assembled bundle of glass optical fibers and clamping members within said sheath and affixing the clamping members to the inner wall of the sheath with the portions of the glass optical fibers disposed between said clamping members free to move within said sheath.

6. A method according to claim 1, wherein said treating step comprises coating the optical fibers with silicone oil.

7. A method according to claim 6, wherein the elastic material is polyvinyl chloride and the step of setting the elastic material comprises bringing it to a temperature of approximately 200* C. and maintaining it at that temperature for approximately 10 minutes.

8. A method according to claim 6, wherein the elastic material is rubber and the setting step comprises heating the elastic material to a temperature of approximately 200* C. and maintaining it at that temperature for approximately 20 minutes.

9. A method according to claim 1, further comprising forming the assembled sheath and optical fibers in a tighter helical coil after the cooling step has been completed, again heating the sheathing material to set it, and again permitting it to cool at a rate sufficient to maintain the new set whereby a tighter helical coil is obtained.

10. An extensible-retractable helically coiled fiber optic assembly produced by the method of claim 1.

11. A method of making an extensible-retractable helically coiled fiber optic assembly, comprising the steps of disposing a bundle of a plurality of flexible optical fibers within a sheath of elastic material having an inner diameter greater than the outer diameter of said bundle of flexible optical fibers so that said plurality of fibers are free to move relative to said sheath, forming the assembled sheath and optical fibers into a helical shape, heating the assembled sheath and optical fibers to a temperature sufficient to set the elastic material and thereafter cooling the elastic sheath and optical fibers at a rate such that the elastic material is set and the optical fibers remain free to move relative to each other and to the elastic sheath, forming the assembled sheath and optical fibers in a tighter helical coil after the cooling step has been completed, again heating the sheathing material to set it, and again permitting it to cool at a rate such that the elastic material is set and the optical fibers remain free to move relative to each other and to the elastic sheath, whereby a tighter helical coil is obtained.