Flexible supporting sheath for cables and the like

• US 5,046,764 A
• Filed: 04/12/1990
• Issued: 09/10/1991
• Est. Priority Date: 04/09/1985
• Status: Expired due to Term

• Current Assignee: Tsubakimoto Chain Company
• Original Assignee: Tsubakimoto Chain Company
• Inventors: Shimomura, Yoshimasa, Kimura, Akira, Yasuda, Hiroshi, Nishimura, Hiroshi, Kitao, Nobuo, Isozaki, Kiyoshi
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Bordas, Carol I.
• Application Number:
  US07/511,858
• Time in Patent Office: 516 Days
• Field of Search: 285/166, 285/167, 285/261, 285/223, 285/184, 403/56, 138/120, 138/155
• US Class Current: 285/154.2
• CPC Class Codes: F16G 13/10 with universal joints
• CPC Class Codes: F16G 13/16 with arrangements for holding electric cables, hoses, or the like
• CPC Class Codes: F16L 3/015 using articulated- or supple-guiding elements
• CPC Class Codes: F16L 57/02 against cracking or buckling
• CPC Class Codes: G02B 6/4461 Articulated
• CPC Class Codes: H02G 11/00 Arrangements of electric cables or lines between relatively-movable parts
• CPC Class Codes: H02G 11/006 using extensible carrier for the cable, e.g. self-coiling spring extensible conductors or cables H01B7/06
• CPC Class Codes: H02G 3/0475 formed by a succession of articulated units
• CPC Class Codes: Y10S 285/921 Snap-fit
• CPC Class Codes: Y10T 403/32032 Plural ball and socket

Abstract

A universally articulable supporting sheath comprises an interconnected series of links, each having a convex spherical surface at one end, and a concave spherical surface at its opposite end. The concave and convex surfaces mate with one another to form the sheath. Special links having branch openings may be provided. Various forms of waterproofing seals are provided, including O-rings, axially compressed rings, flexible belts, and ridges on the spherical surfaces. The links can be fitted together by thermal expansion. However, an axially split link is also described, which comprises two parts which snap together. The split parts may be molded as a unit with an integral thin wall hinge. The bending characteristics and bending radius of a sheath can be modified by insertion of spacers between the links at selected locations, or by the insertion of pins into radial holes provided in the links. Spacers with tongues may be used to prevent rotation of the links about the sheath axis, while allowing unidirectional articulation, Projections on one of a pair of mating spherical surfaces can be engaged with holes, slots or recesses of rectangular or other shapes to produce various limits on articulation and rotation. A single link may be provided with several alternatively usable holes, recesses and the like. The outer surface of a link can be provided with an axial extension engageable with a surface of an adjoining link to prevent back bending, or to prevent bending altogether.

Claims

1. A combined flexible supporting sheath and cable or the like wherein the sheath comprises a series of interconnected links, each link having an internal passage, with circular cross-sections transverse to said link length, extending through it from one end to the other, an inner concave spherical surface formed in the passage at one end of the link, and an outer convex spherical surface formed on the outer surface of the link at its opposite end, in which for each pair of adjoining links of the sheath, the convex surface of one of said adjoining links is engaged with a concave surface of the other one of said adjoining links, in which the centers of the engaged convex and concave surfaces coincide, and in which the concave surface of said other link overlaps the convex surface of said one link to an extent such as to prevent separation of the links, said pair of adjoining links having means for limiting their articulation, the internal passage of each of said pair of links having an intermediate portion located between the concave surface of its passage and the end portion of the passage inside the portion of the link having the outer convex surface, characterized by the fact that the diameter of said end portion of the passage of said one link, from its opening to a location spaced inwardly from said opening a by a distance substantially greater than the distance from said opening to the center of curvature of said outer convex surface, is greater than the minimum diameter of the intermediate portion of the passage of said other link, whereby said pair of adjoining links form a continuous hollow passage for a cable or the like to pass through, and in which said diameter of said end portion is sufficiently greater than the minimum diameter of the intermediate portion of the passage of the other one of said pair of adjoining links, that, when said one link and said other link are bent relative to each other to their limit of articulation, said end of said one link does not extend beyond said intermediate portion of said other link into said continuous hollow passage, whereby flexing of the sheath is prevented from imparting shear and tension to said cable or the like, and in which at least one pair of adjoining links of the sheath has stop means inserted between the outer surfaces of the last-mentioned adjoining links for substantially preventing any articulating movement of said last-mentioned links in any direction.

2. A combined flexible supporting sheath and cable or the like according to claim 1 wherein all of the connected links of said series are substantially identical.

3. A combined flexible supporting sheath and cable or the like according to claim 1 in which said stop means comprises circumferentially tapered means inserted between outer surfaces of the links of said one pair of adjoining links, said stop means maintaining the links of said one pair of adjoining links with the axes of their internal passages intersecting each other at a fixed angle.