MULTI-MEMBER CABLE WITH IMPROVED MID-SPAN ACCESS
20170271046 · 2017-09-21
Assignee
Inventors
Cpc classification
H01B7/17
ELECTRICITY
G02B6/4431
PHYSICS
International classification
Abstract
A multi-member cable includes at least a first cable element and a second cable element. The first and second cable elements twist around a center axis of the cable in a counterclockwise direction multiple times to a first reversal point, then twist about the center axis of the cable in a clockwise direction multiple times until a second reversal point, with this pattern repeating along a length of the cable. Adhesion points are formed at intervals along a length of the cable to connect the first and second cable elements. The adhesion points may be spaced apart at an interval equal to a distance between the first and second reversal points. An outer surface of a jacket of the cable may include indications at the first and/or second reversal points, such as physical bumps or markings.
Claims
1. A multi-member cable comprising: a first cable element; a second cable element, wherein said first and second cable elements twist around a center axis of said multi-member cable three hundred sixty degrees in a counterclockwise direction multiple times to a first reversal point, then said first and second cable elements twist about the center axis of said multi-member cable three hundred sixty degrees in a clockwise direction multiple times until a second reversal point, and wherein said first and second cable elements repeat a pattern of counterclockwise and clockwise twists about the center axis of said multi-member cable between multiple first and second reversal points along a length of said multi-member cable to create a strand lay which repeats direction reversals along the length of said multi-member cable; and adhesion points formed at intervals along a length of said multi-member cable to connect said first cable element to said second cable element, wherein said adhesion points are spaced apart at an interval equal to a distance between said first and second reversal points.
2. The multi-member cable according to claim 1, wherein said adhesion points are formed proximate said first and second reversal points.
3. The multi-member cable according to claim 2, wherein said adhesion points are formed by a melting of a first jacket of said first cable element to a second jacket of said second cable element.
4. The multi-member cable according to claim 2, wherein said adhesion points are formed by an adhesive material located between a first jacket of said first cable element and a second jacket of said second cable element.
5. The multi-member cable according to claim 2, wherein said adhesion points are formed by a wrap located only at said first and second reversal points.
6. The multi-member cable according to claim 2, further comprising: an outer jacket formed over said first and second cable elements.
7. The multi-member cable according to claim 6, wherein an outer surface of said outer jacket includes indications at said first and second reversal points, and wherein said indications are protrusions on said outer surface of said outer jacket caused by materials used to form said adhesion points.
8. The multi-member cable according to claim 1, wherein said first cable element is either a buffer tube with one or more optical fibers therein or an insulated conductor; and wherein said second cable element is either a buffer tube with one or more optical fibers therein or an insulated conductor.
9. The multi-member cable according to claim 1, further comprising: a third cable element; and a fourth cable element, wherein said first, second, third and fourth cable elements twist around the center axis of said multi-member cable three hundred sixty degrees in the counterclockwise direction multiple times to said first reversal point, then said first, second, third and fourth cable elements twist about the center axis of said multi-member cable three hundred sixty degrees in a clockwise direction multiple times until said second reversal point, and wherein said first, second, third and fourth cable elements repeat the pattern of counterclockwise and clockwise twists about the center axis of said multi-member cable between multiple first and second reversal points along the length of said multi-member cable.
10. The multi-member cable according to claim 1, further comprising: a central strength member approximately centered on the center axis of said multi-member cable.
11. The multi-member cable according to claim 10, wherein said first and second cable elements are connected to each other via adhesion points to said central strength member.
12. The multi-member cable according to claim 10, wherein said first and second cable elements are connected via adhesion points to each other and to said central strength member.
13. A multi-member cable comprising: a first cable element; a second cable element, wherein said first and second cable elements twist around a center axis of said multi-member cable three hundred sixty degrees in a counterclockwise direction multiple times to a first reversal point, then said first and second cable elements twist about the center axis of said multi-member cable three hundred sixty degrees in a clockwise direction multiple times until a second reversal point, and wherein said first and second cable elements repeat a pattern of counterclockwise and clockwise twists about the center axis of said multi-member cable between multiple first and second reversal points along a length of said multi-member cable to create a strand lay which repeats direction reversals along the length of said multi-member cable; an adhesion formed between said first and second cable elements along a length of said cable; and an outer jacket formed over said first and second cable elements.
14. The multi-member cable according to claim 13, wherein said adhesion is constant between said first and second cable elements along a length of said cable.
15. The multi-member cable according to claim 14, wherein said adhesion is formed by a melting of a first jacket of said first cable element to a second jacket of said second cable element.
16. The multi-member cable according to claim 14, wherein said adhesion is formed by an adhesive material located between a first jacket of said first cable element and a second jacket of said second cable element.
17. A multi-member cable comprising: a first cable element; a second cable element, wherein said first and second cable elements twist around a center axis of said multi-member cable three hundred sixty degrees in a counterclockwise direction multiple times to a first reversal point, then said first and second cable elements twist about the center axis of said multi-member cable three hundred sixty degrees in a clockwise direction multiple times until a second reversal point, and wherein said first and second cable elements repeat a pattern of counterclockwise and clockwise twists about the center axis of said multi-member cable between multiple first and second reversal points along a length of said multi-member cable to create a strand lay which repeats direction reversals along the length of said multi-member cable; and an outer jacket formed over said first and second cable elements, wherein an outer surface of said outer jacket includes indications at said first reversal points.
18. The multi-member cable according to claim 17, wherein said outer surface of said outer jacket also includes indications at said second reversal points.
19. The multi-member cable according to claim 18, wherein said indications are printed or etched into said outer surface of said outer jacket.
20. The multi-member cable according to claim 18, wherein said indications are protrusions on said outer surface of said outer jacket.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limits of the present invention, and wherein:
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0036] The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0037] Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. Broken lines illustrate optional features or operations unless specified otherwise.
[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.
[0039] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.”
[0040] It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.
[0041] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “lateral”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly.
[0042]
[0043] The third and sixth cable elements 55 and 58 are insulated conductors. For example, the third and sixth cable elements 55 and 58 may be 14 gauge conductors 63 surrounded by an insulation layer 65. The conductors 63 may be solid or stranded, and may be of smaller or larger sizes, e.g., 16 gauge, 12 gauge. The conductors 63 may be formed of copper, copper-clad-steel, aluminum or any other metal or alloy with good electrical conductivity. In practice, the cable elements may also include other power and/or communication mediums, such as a coaxial power conductor, or a twisted pair within a buffer tube, or as an independent cable element.
[0044] In
[0045] The cable core 68 may also be configured with more or less cable elements, such as a five-around-one cable core (five cable elements around a central strength member 67), eight-around-one, ten-around-one or twelve-around-one. Also, the cable elements may have more than one orbit around the central strength member 67. For example, twelve-around-six-around-one (twelve cable elements around six cable elements around a central strength member 67) or fifteen-around-nine-around-one.
[0046] The outer diameter of the outer jacket 69 depends upon the cable core configuration and the size of the cable elements and the central strength member 67. Typical diameters range from 8 mm to 33 mm, such as 29 mm or 30 mm.
[0047] The multi-member cable 51 may optionally include additional elements like a water-blocking tape, water blocking gels inside and/or between the buffer tubes, rip cords, toning signal wires, drain/grounding wires, etc. Absent in
[0048] As best seen in
[0049] The number of turns between the first and second reversal points 27 and 29 depends upon the cable core configuration and dimension of the cable core elements and the central strength member 67. For example, five and half turns to six turns might be feasible for the multi-member cable 51 of
[0050] As previously noted, the multi-member cable 51 of the present invention does not include any binding tapes to hold the cable core 68 together (like the binding tapes 35 and 37 in
[0051] In a first embodiment of the present invention, the cable core 68 is held together during the manufacturing process by an adhesion force. In the first embodiment, the adhesion exists along the entire length of the cable core 68. For example,
[0052] In
[0053] More information about adding an adhesive strip into a cable core can be found in U.S. Pat. No. 7,259,332, which is herein incorporated by reference. U.S. Pat. No. 7,259,332 describes a multi-member cable with no outer jacket. Instead of an outer jacket, the members of the cable core are held together by one or more adhesive members.
[0054] In a second, more preferred, embodiment, the adhesion exists intermittently along the entire length of the cable core. For example,
[0055] In
[0056] In practice, the adhesive strips 73 may be of a short length, e.g., such as greater than 1 mm and less than 30 mm, like between 2 mm and 20 mm, or about 10 mm in length. The adhesive strips 73 are only inserted into the cable core 68 intermittently along a length of the multi-member cable 51 to form adhesion points at spaced intervals along the length of the multi-member cable 51.
[0057] In a preferred embodiment, the adhesion points are spaced apart at an interval equal to the distance A between the first and second reversal points 27 and 29, which is also equal to the distance B. Further, the adhesion points are formed proximate the first and second reversal points 27 and 29. By forming the adhesion points proximate all of the first and second reversal points 27 and 29, the outer jacket 69 will show indications, like bumps 75 on its outer surface, as best seen in
[0058] The bumps 75 along the multi-member cable 51 may be very advantageous to a technician tasked with performing a mid-span access. The technician can determine the switchback points in the core strand by visual inspection or by the physical feel of the outer jacket 69. For example, the bumps 75 may be barely visible, however the human finger can sense extremely small changes in a surface, such as a human hair resting on a flat table. The technician can simply wrap his fingers around the multi-member cable 51 and slide his hand along the outer jacket 69. As the multi-member cable 51 slides through the technician's hand, he should be able sense the switchbacks of the cable core within the outer cable jacket 69 due to the slight bumps 75 along the outer surface of the outer jacket 69.
[0059] By sensing the switchbacks, the drawbacks of the prior art, as discussed above, can be alleviated. The technician will no longer need to be lucky in selecting the locations for the first and second ring cuts in hopes of finding a core strand switchback. Indeed, the entire first cut out section, i.e., the exploratory cut out section to locate a switchback, may be skipped. The technician may proceed to the full cut process, and simply measure the set distances on either side of the located switchback, so as to make only two ring cuts for a mid-span access.
[0060] Instead of using intermediately spaced segments of the adhesive strip 73 at the first and second reversal points 27 and 29 to create the bumps 75, it would also be possible to use intermediately spaced segments of an outer wrap 74 only at the first and second reversal points 27 and 29 in accordance with a third embodiment. For example,
[0061] In a modified first embodiment, the adhesion exists along the entire length of the cable core. For example,
[0062] In
[0063] More information about direct bonding between jackets in a cable core can be found in U.S. Pat. No. 7,259,332, which is herein incorporated by reference. U.S. Pat. No. 7,259,332 describes a multi-member cable with no outer jacket. Instead of an outer jacket, the members of the cable core are held together by one or more adhesive members or by direct bonding of the jackets.
[0064] In an alternative to the second embodiment, the adhesion exists intermittently along the entire length of the cable core. For example,
[0065] In
[0066] In a preferred embodiment, the melt points 80 are spaced apart at an interval equal to the distance A between the first and second reversal points 27 and 29, which is also equal to the distance B. Further, the melt points 80 are formed proximate the first and second reversal points 27 and 29. By forming the melt points 80 proximate all of the first and second reversal points 27 and 29, the cable core will not unravel at the core switchback points during the manufacturing process, e.g., prior to the extrusion of the outer jacket 69 onto the cable core 68.
[0067] It is unlikely that the melting points 80 will cause indications, like perceivable bumps 75, on the outer surface of the jacket 69. Therefore, indications in the form of indicia 82 may be printed or etched into the outer surface of the outer jacket 69, as best seen in
[0068] Like the bumps 75 of
[0069] As best seen in
[0070] Regardless of the adhesion process performed above, the binding tapes 35 and 37 (in
[0071] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.