Abstract A flexible, clad, monofilament optical conduit having a flexible light transmitting polymeric core having a relatively high refractive index which is surrounded by a shrunk, heat shrinkable cladding having a relatively low refractive index in comparison to that of the core and which has a relatively small, uniform gap between the outer periphery of the core and the inner periphery of the heat shrinkable cladding, and a method of manufacture whereby a plurality of such conduits are simultaneously produced by polymerization of the conduit core forming material within a length of unshrunken heat shrinkable material which in turn is contained within a relatively thick, durable protective tubing and removal of the relatively thick protective tubing subsequent to polymerization and then shrinking the heat shrinkable material to form a relatively uniform gap between the core and the clad. In order to prevent its collapse, the heat-shrinkable cladding is pressurized with an inert gas prior to being inserted within the protective tubing.
The process of making a flexible, clad monofilament conduit comprising the steps of: selecting a length of a relatively durable polymeric tubular jacket; cutting a slit along the length of the jacket; selecting a length of tubular cladding form the group, pre-shrunken heat shrinkable fluorinated ethylene-propylene copolymer, perfluoralkoxy resin, and polytetrafluoroethylene tubing; closing one end of said tubular cladding with a stopper; pressurizing said tubular cladding with an inert gas and maintaining pressure; inserting said tubular cladding inside said jacket; removing said stopper and releasing the inert gas from the tubular cladding; placing a polymerizable mixture inside of the tubular cladding; polymerizing the mixture to form a flexible tubular core; removing the jacket; and applying heat to the cladding effective to radially shrink the cladding to form a relatively narrow, uniform gap between the outer periphery of the core and the inner periphery of the cladding.
Claim 2
Dependent Claim
146 words
The process of making a flexible, clad monofilament conduit comprising the steps of: selecting a length of a relatively durable polymeric tubular jacket; cutting a slit along the length of the jacket; selecting a length of tubular cladding form the group, pre-shrunken heat shrinkable fluorinated ethylene-propylene copolymer, perfluoralkoxy resin, and polytetrafluoroethylene tubing; closing one end of said tubular cladding with a stopper; pressurizing said tubular cladding with an inert gas and maintaining pressure; inserting said tubular cladding inside said jacket; removing said stopper and releasing the inert gas from the tubular cladding; placing a polymerizable mixture inside of the tubular cladding; polymerizing the mixture to form a flexible tubular core; removing the jacket; and applying heat to the cladding effective to radially shrink the cladding to form a relatively narrow, uniform gap between the outer periphery of the core and the inner periphery of the cladding.