US2725713A - Cable construction - Google Patents

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Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
  • H01B7/18—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring
  • H01B7/22—Metal wires or tapes, e.g. made of steel
  • H01B7/226—Helicoidally wound metal wires or tapes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/04—Flexible cables, conductors, or cords, e.g. trailing cables
  • H01B7/046—Flexible cables, conductors, or cords, e.g. trailing cables attached to objects sunk in bore holes, e.g. well drilling means, well pumps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2936—Wound or wrapped core or coating [i.e., spiral or helical]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
  • Y10T428/2942—Plural coatings
  • Y10T428/2944—Free metal in coating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2973—Particular cross section
  • Y10T428/2976—Longitudinally varying
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T74/00—Machine element or mechanism
  • Y10T74/20—Control lever and linkage systems
  • Y10T74/20396—Hand operated
  • Y10T74/20402—Flexible transmitter [e.g., Bowden cable]
  • Y10T74/20456—Specific cable or sheath structure

Definitions

• the present invention relates to cables and more particularly to armored electrical cables of the type etnapplicant, for Electric Cablefnow Patent No. 2,604,509,
• electric cables designed for use Yin operations such as electrical logging, gun perforating and the like in deep oil wells, have usually comprised a core including a group of helically wound, short la insulated conductors ⁇ surrounded by two protective, load carrying layers of steel armor, the layers being wound in opposite directions around the core.
• lt is well known that the stresses in a cable of this type, when unwound into a bore hole, vary from ay minimum value at the lower endto a maximum value at the upper end which is usually wound on a winch at the surface of the earth.
• lt is an object of the present invention to provide a new and improved cable constructionwhich is free from the above-noted deticienc'ies of the prior art;
• Another object ot the invention is to provide a new and improved cable construction in which the cross-sectional area of the cable is substantially uniform along its length. although the load carrying portion of the cable is tapered from one end to the other.
• a further object of the invention is to provide a new and improved cable construction embodying means for alleviating wear due to abrasion as a function of the wear anticipated at different portions of the length thereof.
• the coating is applied to individual strands as required to maintain a substantially uniform cross-section along the length of the cable.
• Fig. l illustrates a cable constructed according to the invention, lowered into a bore hole drilled into the earth;
• Fig. 2 is a view in transverse section taken along the line 2.-2 of Fig. l and looking in the direction of the arrows;
• Fig. 3 is a view in transverse section taken along the line 3 3 of Fig. l and looking in the direction of the arrows.
• a cable 10 constructed according to the invention is shown supporting well logging apparatus ll., for example, in a bore hole l2 drilled into the earth.
• the cable lli passes over a pulley 13 at the surface of the earth and its upper end may be secured to :i conventional winch ifi by means of which the apparatus l1 may be lowered into and withdrawn from the well l2.
• the cable .lill may comprise, for example, a core l5 which may include one or more insulated electrical conductors lo formed in a short lay helix, for example. While six confductors lo are shown in Fig. 2, obviously, any desired number may be employed.
• the conductors 1.5. are covered by a layer i7 of any suitable material such as textile braid, plastic, or tape wrapping which serves to hold them in place and insures essentially circular form for the core l5.
• Slurrouriding the core l5 is an inner layer of armor lit comprising a plurality of metal strands 19 which are preferably preformed and which are wound in a helix about the core l5.
• the pitch of the strands i9 should preferably be so chosen that the layer ot' armor l5 substantially covers the core l5. While twenty-four strands i9 are shown in Fig. 2., the exact number employed any case will depend upon strength and lay desired.
• the cables employed usually haveV from eighteen to twenty-eight strands in the inner layer of armor.
• Wound on top of the inner layer ld is outer layer of armor 2% comprising a plurality of metal strands 2l Wound in the opposite direction to the strands i9.
• the cross-sectional area of the load carrying ⁇ portion of the cable comprisingY the arinors lil and 2li is tapered from the top of the cable to the bottoni so that the cable will have different load carrying properties at dverent points along its length.
• the crossasectionai areas of the armors .lil and 26 will be'relativcly large as required to support the load represented by the weight ot the well logging apparatus le and the portion of the cable suspended in the well.
• a coating 22 may be applied to the individual strands 21. comprising the outer armor 20, or a coating 23 may be applied to the strands 19 comprising the inner armor 13, or coatings may be applied to both sets of strands as required to maintain a substantially uniform cross-sectional area for t'ne cable from top to bottom.
• the properties of the coating for the strands will depend upon the specic characteristics desired for the cable. In general, it should be tough and relatively resistant to abrasion but it can be or low tensile strength since it does not carry any of the load. if the cable should be insulated from any casing that may be in a well, a coating having suitable insulating properties may be provided for this purpose. On the other hand, if a cable of minimum density is desired, a coating material having a density less than that of steel should be employed.
• Suitable coating materials may comprise any of the so-called plastic compounds with or without inert llers, such as synthetic liber forming polymeric amides having a protein-like chemical structure, acetol type of polyvinyl resins, or rubber, for example. lf electrical insulating properties are not essential, metal having a low modulus of elasticity might be employed as the coating material.
• the coating may be applied in any conventional manner, such as by extrusion, dipping, polymerization or electrolytic deposition.
• the invention thus provides a novel and highly eiective cable construction which is of particular utility for use in wells drilled into the earth, although it is not limited to this eld.
• a coating having a thickness which is a maximum at the bottom and which varies inversely with the distance from the bottom, the problem of uneven wear due to abrasion may be alleviated.
• the load carrying portion of the cable may be tapered from one end to the other, so as to have dilerent load carrying properties at different points therealong While maintaining a substantially uniform crosssectional area along the cable.
• l. ln a load bearing cable adapted tor use in a bore hole or the like, the combination of a tapered load carrying portion, and a coating on the outside of said cable having a thickness which is a maximum at the one end of the cable at which the load carrying portion has the least cross-sectional area and is progressively less at different locations between the two ends of the cable in inverse relation to the distance from said one end.
• a load carrying portion the cross-sectional area of which varies as a function of the length of said cable, and a nonload carrying portion the thickness of which varies inversely with the cross-sectional area of said load carrying portion so as to maintain the cross-sectional area of said cable substantially constant over its length.
• a load bearing cable having a load carrying cross-section that tapers from one end to the other so as to have dilerent load carrying properties at different points therealong, and a coating formed on portions of said cable, said coating being made of a tough, essentially non-load carrying, abrasion-resistant material and having a thickness which varies inversely with the load carrying cross-section of the cable so as to maintain a substantially uniform cross-section along the cable.
• a load bearing cable adapted for use in a bore hole or the like, the combination of a core, load carrying armor means comprising metallic strands wound over said core, the cross-sectional area of said armor means varying from a maximum at one end of the cable to a minimum at the other end of the cable, and a tough, non-load carrying coating for metallic strands of said armor means, the thickness of said coating varying inversely with the crosssectional area of said armor means so as to maintain the cross-sectional area of the cable substantially constant over the length thereof.
• a load bearing cable having a load carrying portion that is tapered from one end to the other so as to have different load carrying properties at different points therealong, and a coating on said cable having a thickness varying inversely with variations in the diameter of the load carrying portion so as to maintain the cross-sectional area of the cable substantially uniform along its length.

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• Insulated Conductors (AREA)

Description

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26692074

Family Applications (1)

Country Status (1)

Cited By (28)

Citations (4)

• 1952
  • 1952-05-13 US US287572A patent/US2725713A/en not_active Expired - Lifetime

Patent Citations (4)

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