Buoyant tether cable

• US 4,110,554 A
• Filed: 02/08/1978
• Issued: 08/29/1978
• Est. Priority Date: 02/08/1978
• Status: Expired due to Term

• Current Assignee: Custom Cable Company
• Original Assignee: Custom Cable Company
• Inventors: Moore, Boyd B., Kendall, Clarence E. Jr.
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Bouchard, John H.
• Application Number:
  US05/875,953
• Time in Patent Office: 202 Days
• Field of Search: 174/27, 174/70 R, 174/101.5, 174/113 R, 174/115, 174/116
• US Class Current: 174/101.5
• CPC Class Codes: D07B 1/147 comprising electric conductors or elements for information transfer D07B1/145 takes precedence
• CPC Class Codes: D07B 1/20 Buoyant ropes, e.g. with air-filled cellular cores; Accessories therefor
• CPC Class Codes: H01B 11/02 Cables with twisted pairs or quads
• CPC Class Codes: H01B 11/1891 comprising auxiliary conductors
• CPC Class Codes: H01B 7/04 Flexible cables, conductors, or cords, e.g. trailing cables
• CPC Class Codes: H01B 7/12 Floating cables

Abstract

A flexible, high load bearing, electrically conductive buoyant tether cable includes a center stress core having a plurality of jacketed stress bearing members which are in turn enclosed within a plastic-like core jacket. Seven conductor elements are cabled around the core, including three pairs of conductor elements and a jacketed coaxial cable. Each of the conductor element pairs includes a core, five twisted pairs of individually insulated, electrically conductive wires cabled around the conductor element core and a conductor tape binder surrounding the cabled pairs of wires. The conductor elements are cabled around the center stress core and are themselves enclosed by an outer tape binder and jacket. A plurality of intersticial stress members occupies a portion of the corresponding interstices between the cabled conductor elements and the outer tape binder. The interstices within the central stress bearing elements remain hollow for buoyancy while all other interstices within the tether cable are substantially filled with thin walled, hollow glass microspheres for increased buoyancy of the cable which tends to prevent the collapse of the cable from pressure when used in deep water operations.

Claims

1. A high tensile strength electrically conductive buoyant tether cable comprising:

(a) a center stress core having,

(i) a plurality of cabled stress-bearing elements having a low density, high strength plastic-like jacket circumferentially defining each stress-bearing element;

(ii) a core tape binder circumferentially enclosing the plurality of inner stress-bearing elements (i);

(iii) a plurality of inner interstices formed by the exterior surfaces of the stress-bearing elements (i) and the core tape binder (ii); and

(iv) microspheres substantially occupying the plurality of inner interstices (iii);

(b) a plurality of conductor elements cabled around the center stress core (a) including;

(i) a first pair of conductor elements each composed of a plastic-like conductor core, a plurality of twisted insulated wires cabled around said plastic-like conductor core, a conductor tape binder enclosing the plurality of twisted pairs of wires whereby interstices are formed among the twisted pairs of wires, the plastic-like core and the plastic-like conductor tape binder, and a quantity of microspheres substantially occupying said interstices;

(ii) a second pair of conductor elements each substantially identical to the first pair of conductor elements (i);

(iii) a third pair of conductor elements each substantially identical to the first pair of conductor elements (i); and

(iv) a coaxial cable having a plastic-like external jacket circumferentially enclosing said coaxial cable;

(c) mid interstices formed by the center stress core (a) and the plurality of conductor elements (b), said mid interstices substantially filled with microspheres;

(d) an outer plastic-like tape binder circumferentially surrounding and in close proximity to the plurality of conductor elements (b) cabled around the core (a) such that outer interstices are formed between the conductor elements and the outer tape binder;

(e) at least one interstitial stress member located within and partially occupying each of the outer interstices (d);

(f) an outer jacket circumferentially surrounding the outer tape binder (d); and

(g) a quantity of microspheres occupying the volume of each outer interstices not occupied by an interstitial stress member (e) thereby forming a flexible, tensional load bearing, electrically conductive buoyant tether cable suitable for underwater operations.

2. The device of claim 1 wherein each of the cabled stress-bearing elements (a) (i) comprises:

(a) three twisted stress-bearing members; and

(b) a jacket circumferentially surrounding the twisted stress-bearing members whereby unfilled interstices are formed between the cabled stress-bearing members (a) and said jacket.

3. The device of claim 1 wherein the stress-bearing elements comprise six stress-bearing elements cabled around a central core element.

4. The device of claim 1 wherein at least one of the plastic-like cores of the conductor elements (b) (i), (ii) and (iii) includes a hollow center for increased buoyancy.

5. The device of claim 1 wherein at least one of the conductor cores of conductor elements (b) (i), (ii) or (iii) is a low density polyethylene material tube extruded on a twisted polypropylene fiber core.

6. The device of claim 1 wherein at least one of the plastic-like cores of the conductor elements (b) (i) is a low density, high strength plastic-like material.

7. The device of claim 1 wherein at least one of the plastic-like cores of the conductor elements (b) (ii) is a low density, high strength plastic-like material.

8. The device of claim 1 wherein at least one of the plastic-like cores of the conductor elements (b) (iii) is a low density, high strength plastic-like material.

9. The device of claim 1 wherein the outer jacket (f) is a polyurethane jacket.

10. The device of claim 1 wherein the first pair of conductor elements (b) (i) is electrically parallel.

11. The device of claim 1 wherein the second pair of conductor elements (b) (ii) is electrically parallel.

12. The device of claim 1 wherein the third pair of conductor elements (b) (iii) is electrically parallel.

13. A high tensional load bearing, electrically conductive, buoyant tether cable comprising:

(a) a core having;

(i) a central core element including three twisted stress-bearing members, a low density, high strength plastic jacket circumferentially surrounding said stress-bearing members, and unfilled interstices formed between the three twisted stress-bearing members and the jacket;

(ii) six stress-bearing elements substantially identical to and cabled around the central core element (i) whereby interstices are formed between said six cabled stress-bearing elements and said central core element (i);

(iii) a low density, high strength plastic-like core tape binder circumferentially surround the six cabled stress-bearing elements (ii) and central core element (i) whereby interstices are formed between the cabled stress-bearing elements (ii), the central core element (i) and said tape binder; and

(iv) a quantity of microspheres substantially filling the volumes of the interstices formed in (ii) and (iii);

(b) seven conductor elements cabled around the core (a) wherein;

(i) each of a first pair of said conductor elements comprises a low density, high strength plastic-like conductor core, five twisted pairs of insulated conductive wires cabled around the conductor core wherein interstices are formed between the conductor core and the five pairs of twisted wires, a low density, high strength plastic-like conductor tape binder circumferentially enclosing the five twisted pairs of conducting wires cabled around the conductor core whereby interstices remain between the five twisted pairs of conductive wires and said conductor tape binder and a quantity of microspheres substantially fills the interstices formed within each of the first pair of conductor elements;

(ii) each of a second pair of said conductor elements comprises a low density, high strength plastic-like conductor core, five twisted pairs of insulated conductive wires cabled around the conductor core wherein interstices are formed between the conductor core and the five pairs of twisted wires, a low density, high strength plastic-like conductor tape binder circumferentially enclosing the five twisted pairs of conductive wires cabled around the conductor core whereby interstices remain between the five twisted pairs of conductive wires and said conductor tape binder and a quantity of microspheres substantially fills the interstices formed within each of the second pair of conductor elements;

(iii) each of a third pair of conductor elements comprises a low density, high strength plastic-like conductor core, five twisted pairs of insulated conductive wires cabled around the conductor core wherein interstices are formed between the conductor core and the five pairs of twisted wires, a low density, high strength plastic-like conductor tape binder circumferentially enclosing the five twisted pairs of conductive wires cabled around the conductor core whereby interstices remain between the five twisted pairs of conductive wires and said conductor tape binder and a quantity of microspheres substantially fills the interstices formed within each of the third pairs of conductor elements; and

(iv) a conventional coaxial cable having a low density, high strength plastic-like jacket contiguous to and circumferentially enclosing said coaxial cable;

(c) an outer tape binder circumferentially enclosing the seven cabled conductor elements (b);

(d) interstices formed between the seven conductor elements (b) and the core (a);

(e) interstices formed between the seven cabled conductor elements (b) and the outer tape binder (c);

(f) a two-strand twisted aramid fiber stress member cabled into each interstice (e); and

(g) a quantity of microspheres substantially occupying the volume of the interstices (d) and the unoccupied volume of the interstices (e); and

(h) a urethane outer jacket circumferentially surrounding the outer tape binder (c).

14. The device of claim 13 wherein at least one of the conductor cores of conductor elements (b) (i), (ii) or (iii) is a low density polyethylene material tube extruded on a twisted polypropylene fiber core.