Flexible tube for an endoscope

A flexible tube for an endoscope, comprising:

• a spiral tube;
• a netted tube covering an outer surface of said spiral tube, said netted tube being formed by braiding a plurality of strand bundles each formed by closely arranging a plurality of fine wires in parallel, said plurality of fine wires comprising at least one metal fine wire and at least one non-metal fine wire;
• and
• a jacket made of a flexible synthetic resin which covers an outer surface of said netted tube;
• wherein a braid density K of said netted tube lies in a range of 0.788.ltoreq.K.ltoreq.0.906;
• wherein K=(S-s)/S;
• wherein "S" is an area of an intersection of two strand bundles in union with an area of a gap between said intersecting strand bundles and neighboring strand bundles of one side of said intersecting strand bundles, the widths of said area "S" being substantially equal;
• and
• wherein "s" is the area of the gap produced by the intersecting strand bundles, wherein no strands are covered, the widths of said area "s" being substantially equal.

A netted tube, formed by braiding a plurality of strand bundles each formed by closely arranging a plurality of fine wires in parallel, used in a flexible tube for an endoscope, said flexible tube comprising:

• a spiral tube, said netted tube covering an outer surface of said spiral tube;
• and
• a jacket made of a flexible synthetic resin which covers an outer surface of said netted tube;
• wherein the following relationships are satisfied:
• 45.degree..ltoreq..alpha..ltoreq.65.degree.,
• 0.772.ltoreq.K.ltoreq.0.906
• and
• n=24,
• wherein ".alpha." represents a braid angle, "K" represents a braid density, and "n" represents a number of strands contained in one of said plurality of strand bundles,
• and further wherein said number "n" satisfies all the following relationships:
• 2.89 D.ltoreq.n.ltoreq.6.41 D when dw is equal to 0.02 mm,
• 1.93 D.ltoreq.n.ltoreq.4.27 D when dw is equal to 0.03 mm,
• 1.45 D.ltoreq.n.ltoreq.3.20 D when dw is equal to 0.04 mm,
• 1.16 D.ltoreq.n.ltoreq.2.56 D when dw is equal to 0.05 mm,
• 0.97 D.ltoreq.n.ltoreq.2.13 D when dw is equal to 0.06 mm,
• 0.83 D.ltoreq.n.ltoreq.1.83 D when dw is equal to 0.07 mm,
• 0.73 D.ltoreq.n.ltoreq.1.60 D when dw is equal to 0.08 mm,
• 0.65 D.ltoreq.n.ltoreq.1.42 D when dw is equal to 0.09 mm,
• 0.58 D.ltoreq.n.ltoreq.1.28 D when dw is equal to 0.10 mm, and
• 0.49 D.ltoreq.n.ltoreq.1.06 D when dw is equal to 0.12 mm,
• wherein "dw" represents a diameter of a strand of each strand bundle in said plurality of strand bundles and "D" represents an average diameter of said netted tube;
• wherein K=(S-s)/S;
• wherein "S" is an area of an intersection of two strand bundles in union with an area of a gap between said intersecting strand bundles and neighboring strand bundles of one side of said intersecting strand bundles, the widths of said area "S" being substantially equal;
• and
• wherein "s" is the area of the gap produced by the intersecting strand bundles, wherein no strands are covered, the widths of said area "s" being substantially equal.

A netted tube, formed by braiding a plurality of strand bundles each formed by closely arranging a plurality of fine wires in parallel, used in a flexible tube for an endoscope, said flexible tube comprising:

• a spiral tube, said netted tube covering an outer surface of said spiral tube;
• and
• a jacket made of a flexible synthetic resin which covers an outer surface of said netted tube;
• wherein the following relationships are satisfied:
• 45.degree..ltoreq..alpha..ltoreq.65.degree.,
• 0.772.ltoreq.K.ltoreq.0.906
• and
• n=32,
• wherein ".alpha." represents a braid angle, "K" represents a braid density, and "n" represents a number of strands contained in one of said plurality of strand bundles,
• and further wherein said number "n" satisfies all the following relationships:
• 2. 17 D.ltoreq.n.ltoreq.4.81 D when dw is equal to 0.02 mm,
• 1.45 D.ltoreq.n.ltoreq.3.20 D when dw is equal to 0.03 mm,
• 1.09 D.ltoreq.n.ltoreq.2.40 D when dw is equal to 0.04 mm,
• 0.87 D.ltoreq.n.ltoreq.1.92 D when dw is equal to 0.05 mm,
• 0.73 D.ltoreq.n.ltoreq.1.60 D when dw is equal to 0.06 mm,
• 0.62 D.ltoreq.n.ltoreq.1.37 D when dw is equal to 0.07 mm,
• 0.55 D.ltoreq.n.ltoreq.1.20 D when dw is equal to 0.08 mm,
• 0.49 D.ltoreq.n.ltoreq.1.06 D when dw is equal to 0.09 mm,
• 0.44 D.ltoreq.n.ltoreq.0.96 D when dw is equal to 0.10 mm, and
• 0.37 D.ltoreq.n.ltoreq.0.80 D when dw is equal to 0.12 mm,
• wherein "dw" represents a diameter of a strand of each strand bundle in said plurality of strand bundles and "D" represents an average diameter of said netted tube;
• wherein K=(S-s)/S,
• wherein "S" is an area of an intersection of two strand bundles in union with an area of a gap between said intersecting strand bundles and neighboring strand bundles of one side of said intersecting strand bundles, the widths of said area "S" being substantially equal;
• and
• wherein "s" is the area of the gap produced by the intersecting strand bundles, wherein no strands are covered, the widths of said area "s" being substantially equal.

A netted tube, formed by braiding a plurality of strand bundles each formed by closely arranging a plurality of fine wires in parallel, used in a flexible tube for an endoscope, said flexible tube comprising:

• a spiral tube, said netted tube covering an outer surface of said spiral tube;
• and
• a jacket made of a flexible synthetic resin which covers an outer surface of said netted tube;
• wherein the following relationships are satisfied:
• 4.degree..ltoreq..alpha..ltoreq. 6.degree. .
• 0.772.ltoreq.K.ltoreq.0.906
• and
• n=16,
• wherein ".alpha." represents a braid angle, "K" represents a braid density, and "n" represents a number of strands contained in one of said plurality of strand bundles,
• and further wherein said number "n" satisfies all the following relationships:
• 4.34 D.ltoreq.n.ltoreq.9.62 D when dw is equal to 0.02 mm,
• 2.89 D.ltoreq.n.ltoreq.6.41 D when dw is equal to 0.03 mm,
• 2.17 D.ltoreq.n.ltoreq.4.81 D when dw is equal to 0.04 mm,
• 1.74 D.ltoreq.n.ltoreq.3.84 D when dw is equal to 0.05 mm,
• 1.45 D.ltoreq.n.ltoreq.3.20 D when dw is equal to 0.06 mm,
• 1.24 D.ltoreq.n.ltoreq.2.74 D when dw is equal to 0.07 mm,
• 1.09 D.ltoreq.n.ltoreq.2.40 D when dw is equal to 0.08 mm,
• 0.97 D.ltoreq.n.ltoreq.2.13 D when dw is equal to 0.09 mm,
• 0.87 D.ltoreq.n.ltoreq.1.92 D when dw is equal to 0.10 mm, and
• 0.73 D.ltoreq.n.ltoreq.1.60 D when dw is equal to 0.12 mm,
• wherein "dw" represents a diameter of a strand of each strand bundle in said plurality of strand bundles and "D" represents an average diameter of said netted tube;
• wherein K=(S-s)/S;
• wherein "S" is an area of an intersection of two strand bundles in union with an area of a gap between said intersecting strand bundles and neighboring strand bundles of one side of said intersecting strand bundles, the widths of said area "S" being equal;
• and
• wherein "s" is the area of the gap produced by the intersecting strand bundles, wherein no strands are covered, the widths of said area "s" being equal.

A netted tube, formed by braiding a plurality of strand bundles each formed by closely arranging a plurality of fine wires in parallel, used in a flexible tube for an endoscope, said flexible tube comprising:

• a spiral tube, said netted tube covering an outer surface of said spiral tube;
• and
• a jacket made of a flexible synthetic resin which covers an outer surface of said netted tube;
• wherein the following relationships are satisfied:
• 45.degree..alpha..ltoreq.65.degree.,
• 0.772.ltoreq.K.ltoreq.0.906
• and
• n=8,
• wherein ".alpha." represents a braid angle, "K" represents a braid density, and "n" represents a number of strands contained in one of said plurality of strand bundles,
• and further wherein said number "n" satisfies all the following relationships:
• 8.67 D.ltoreq.n.ltoreq.19.24 D when dw is equal to 0.02 mm,
• 5.78 D.ltoreq.n.ltoreq.12.82 D when dw is equal to 0.03 mm,
• 4.34 D.ltoreq.n.ltoreq.9.62 D when dw is equal to 0.04 mm,
• 3.47 D.ltoreq.n.ltoreq.7.69 D when dw is equal to 0.05 mm,
• 2.89 D.ltoreq.n.ltoreq.6.41 D when dw is equal to 0.06 mm,
• 2.48 D.ltoreq.n.ltoreq.5.49 D when dw is equal to 0.07 mm, and
• 2.17 D.ltoreq.n.ltoreq.4.81 D when dw is equal to 0.08 mm,
• wherein "dw" represents a diameter of a strand of each strand bundle in said plurality of strand bundles and "D" represents an average diameter of said netted tubes;
• wherein K=(S-s)/S;
• wherein "S" is an area of an intersection of two strand bundles in union with an area of a gap between said intersecting strand bundles and neighboring strand bundles of one side of said intersecting strand bundles, the widths of said area "S" being substantially equal;
• and
• wherein "s" is the area of the gap produced by the intersecting strand bundles, wherein no strands are covered, the widths of said area "s" being substantially equal.