Flexible sheathing tube construction, and method for fabrication thereof

• US 5,762,995 A
• Filed: 07/25/1996
• Issued: 06/09/1998
• Est. Priority Date: 01/13/1995
• Status: Expired due to Fees

• Current Assignee: Fujinon Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Inventors: Kobayashi, Hirokazu, Takahashi, Nobuharu, Kondo, Mituo
• Primary Examiner(s): DUDASH, DIANA L
• Application Number:
  US08/684,912
• Time in Patent Office: 684 Days
• Field of Search: 427/239, 427/231, 427/235, 427/236, 427/232, 427/2.12, 427/2.3, 427/178, 427/409
• US Class Current: 427/2.12
• CPC Class Codes: A61B 1/00071 Insertion part of the endoscope body A61B1/0055 takes precedence
• CPC Class Codes: A61B 1/005 Flexible endoscopes
• CPC Class Codes: A61B 1/0055 Constructional details of insertion parts, e.g. vertebral elements
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: F16L 11/088 comprising a combination of one or more layers of a helically wound cord or wire with one or more braided layers

Abstract

A flexible sheathing tube suitable for encasing an elongated flexible body like a flexible insertion rod of an endoscope or other insertion type examination instrument, and a method for fabrication of such sheathing tubes. The flexible sheathing tube being of the type is basically provided with a flexible base structure having at least an open helical coil member of a cylindrical shape, a protective mesh sleeve fitted on the helical coil member, and an insulating outer coating layer formed on the protective mesh sleeve. The sheathing tube is further provided with an inner coat layer of a resilient material formed on the inner side of the helical coil member in such a manner as to cover the inner periphery of the helical coil member completely, filling in gap spaces between open helices of the coil member.

Claims

1. A method for fabricating a multi-layered flexible tube for an insertion tube of an intracavitary examination instrument, said method comprising the steps of:

helically winding a metal strip having a width to form an open helical coil tube including helices in an open pitch;

fitting a protective mesh sleeve around an outer periphery of said open helical coil tube;

forming an outer skin layer to cover an outer periphery of said mesh sleeve so as to obtain a multi-layered flexible tube structure;

closing one longitudinal end of said multi-layered flexible tube structure with a closing member;

filling a liquid resilient material through the other longitudinal end of said multi-layered flexible tube structure into said multi-layered flexible tube structure which is closed at the one longitudinal end;

holding said liquid resilient material in said multi-layered flexible tube structure so as to form a resilient material coat layer on an entire inner periphery of said multi-layered flexible tube structure and so as to fill in gap spaces between open helices of said open helical coil tube; and

removing said closing member to drain said liquid resilient material from said multi-layered flexible tube structure.

2. A method for fabricating a multi-layered flexible tube as defined in claim 1, wherein said filling step comprises providing said liquid resilient material having a drying speed sufficiently low that the thickness of the inner coat can be controlled by the flow of the resilient material, further comprising a step of:

after said removing step, retaining said multi-layered flexible tube structure in a position in which a longitudinal axis of said multi-layered flexible tube structure is substantially parallel to a vertical direction in order to vary a thickness of said resilient material coat layer along the longitudinal axis.

3. A method for fabricating a multi-layered flexible tube for an insertion tube of an intracavitary examination instrument, said method comprising the steps of:

helically winding a metal strip having a width to form an open helical coil tube including helices in an open pitch;

fitting a protective mesh sleeve around an outer periphery of said open helical coil tube;

forming an outer skin layer to cover an outer periphery of said mesh sleeve so as to obtain a multi-layered flexible tube structure having opposite first and second ends in a longitudinal direction of said multi-layered flexible tube structure;

closing said first end of said multi-layered flexible tube structure with a closing member;

filling a first liquid resilient material into said multi-layered flexible tube structure up to a first level through said second end of said multi-layered flexible tube structure;

holding said first liquid resilient material in said multi-layered flexible tube structure so as to form a first resilient material coat layer on a part of an inner peripheral surface of said multi-layered flexible tube structure;

removing said closing member to drain said first liquid resilient material from said multi-layered flexible tube structure;

closing said second end of said multi-layered flexible tube structure with a closing member;

filling a second liquid resilient material having hardness properties different from those of said first liquid resilient material into said multi-layered flexible tube structure up to a level partially overlapping with an edge of said first resilient material coat layer through said first end of said multi-layered flexible tube structure;

holding said second liquid resilient material in said multi-layered flexible tube structure so as to form a second resilient material coat layer on the inner peripheral surface of said multi-layered flexible tube structure; and

removing said closing member to drain said second liquid resilient material from said multi-layered flexible tube structure.

4. A method for fabricating a multi-layered flexible tube for an insertion tube of an intracavitary examination instrument, said method comprising the steps of:

helically winding a first metal strip having a width to form a first layer of an open helical coil tube including helices in an open pitch;

fitting a first protective mesh sleeve around an outer periphery of said open helical coil tube to form a laminated tube structure;

dipping said laminated tube structure in a liquid resilient material to form a resilient material coat layer on entire inner and outer peripheries of said laminated tube structure;

helically winding a second metal strip having a predetermined width around an outer periphery of said coated laminated tube structure to form a second layer of an open helical coil tube in a predetermined open pitch;

fitting a second protective mesh sleeve around an outer periphery of said second layer of an open helical coil tube; and

forming an outer skin layer to cover an outer periphery of said second mesh sleeve.