ETHERNET CABLE CROSS-FILLER WITH NOTCHES

Abstract

“A cross filler for arrangement within a LAN cable has a plurality of twisted pair conductors. The cross filler has a body and a plurality of radially extending arms from a center point. Each of the arms has a plurality of spaced apart notches cut into the arms, the notches spaced apart along the length of the arms. Each of the notches are dimensioned allowing bending of the LAN cable without physical breakdown of the cross filler.”

Claims

1. A cross filler for arrangement within a LAN cable having a plurality of twisted pair conductors, said cross filler comprising: a body; and a plurality of radially extending arms from a center point; wherein each of said arms has a plurality of spaced apart notches cut into said arms, said notches spaced apart along the length of said arms; wherein each of said notches are dimensioned to improve flexibility of said LAN cable and said cross-filler, without physical breakdown of said cross filler.

2. The cross filler as claimed in claim 1, wherein said cross filler has four arms radiating from said center point, at substantially 90 degrees from one another.

3. The cross filler as claimed in claim 2, wherein said notches in said cross filler are cut into each of said four arms.

4. The cross filler as claimed in claim 3, wherein each of said four arms include said notches disposed at the same longitudinal length along the length of said arms.

5. The cross filler as claimed in claim 4, wherein said notches are spaced along the longitudinal length of said arms such that there is at least one (1) notch per arm, per quadrant of bend radius, equating to a maximum notch spacing of 2π times and OD (Outside Diameter) for said cable, when said cable is an UTP (Unshielded Twisted Pair) cable.

6. The cross filler as claimed in claim 5, wherein said spacing for said notches for said cable, having an OD (Outside Diameter) of 0.225″, spacing would be at approximately 1.41″ between successive notches.

7. The cross filler as claimed in claim 5, wherein spacing between successive notches is varied above and below and average spacing.

8. The cross filler as claimed in claim 4, wherein said notches are spaced along the longitudinal length of said arms such that there is at least one (1) notch per arm, per quadrant of bend radius, equating to a maximum notch spacing of 4π times and OD (Outside Diameter) for said cable, when said cable is a shielded twisted pair cable.

9. The cross filler as claimed in claim 1, wherein said notches are cut into said arms to a depth down to said center point.

10. The cross filler as claimed in claim 9, wherein said notches are cut with a width of substantially zero.

11. The cross filler as claimed in claim 2, wherein said notches in said cross filler are cut into at least one of said four arms.

12. The cross filler as claimed in claim 2, wherein said notches in said cross filler are cut into at least two of said four arms.

13. The cross filler as claimed in claim 2, wherein said notches in said cross filler are cut into at least three of said four arms.

14. The cross filler as claimed in claim 2, wherein said notches in said cross filler are cut into all four arms.

15. The cross filler as claimed in claim 9, wherein said notches are cut with a width of greater than zero but a width less than ½ a lay length of one of said twisted pairs with a tightest length.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention can be best understood through the following description and accompanying drawings, wherein:

[0010] FIG. 1 shows a prior art cross filler for a LAN cable;

[0011] FIG. 2 shows the prior art cross filler for a LAN cable of FIG. 1 in perspective view;

[0012] FIG. 3 illustrates a notched cross filler for a LAN cable, in accordance with one embodiment;

[0013] FIG. 4 illustrates the notched cross filler for a LAN cable of FIG. 3 in perspective view, in accordance with one embodiment;

[0014] FIG. 5 illustrates the notched cross filler for a LAN cable of FIG. 3 in perspective view and in a bent position, in accordance with one embodiment; and

[0015] FIG. 6 illustrates the notched cross filler for a LAN Cable of FIG. 3 within a jacket of the cable and with spaced notches, in accordance with one embodiment.

DETAILED DESCRIPTION

[0016] In one embodiment of the present arrangement, as shown in FIGS. 3 and 4, the present arrangement includes a LAN cable 10 having four twisted pairs 12a-12d and a cross filler 20. Although the present example is shown for a four twisted pair LAN cable, the features of the present cross filler 20 described herein may be equally employed in other cable arrangements requiring internal spacing as well as LAN cables including more or fewer twisted pairs. In one example, cross filler 20 may be constructed by pressure or drawdown extrusion using a shaped die and made from any one of FRPVC (Flame retardant Poly Vinyl Chloride), FRPE (Flame retardant Poly Ethylene), FRPP (Flame retardant Poly Propylene), PE (Poly Ethylene), PP (Poly Propylene), FEP (Fluorinated Ethylene Co-Polymer), PFA (Perfluoroalkoxy alkanes) and other polymers commonly used in the construction of LAN cables.

[0017] As shown in FIGS. 3-4, cross filler 20 includes a central region 21 and four radically extending arms 22A-22D. Each of arms 22 has a given length from the center of filler 20 as well as a plurality of notches 26 or cuts disposed along the longitudinal length of the cable. Standard cross filler designs such as those in FIGS. 1 and 2 naturally resist being bent or curved because of their geometry. Adding perpendicular notches or cuts 26 to arm 22 of cross filler 10 alleviates this resistance and allows the cables to bend and flex easier as shown in FIG. 5.

[0018] In one embodiment, notches/cuts 26 can be as small as small as a width of zero (0) (in other words just a cut in the arm without removal of material). In another embodiment larger widths for notches/cuts 26 may be used as long as such cuts 26 do not allow twisted pairs 12 to pass through notches 26 and move, even partially, across arm 22 into an area for adjacent pair 12. As an example, in this embodiment with wider notches/cuts 26 would be less than ½ the lay length of the tightest lay of an adjacent pair 12. In one example, such notches 26 may be made by a rotary cutting wheel either during the extrusion operation, or during the cabling operation (or wherever cross filler 20 is being pulled into cable 10.

[0019] In one embodiment, regarding the depth of cuts/notches 26 into arms 22, a maximum depth could be set to equal to the dimension of the arm 22 (in other word down to the center point of the cross), as long as it does not go past the center axis.

[0020] Regarding the longitudinal spacing of cuts 26 along the length of arms 22 of cross filler 20, such spacing is a function of a desired bend radius of cable 10. In this case, bend radius refers to the tightest bend radius around which cable 10 can be wound without destroying the cable or resulting in an unacceptable level of attenuation relative to the desired standards of the cable construction. The tighter/smaller the bend radius the closer the spacing of notches 26. In one embodiment, as shown in FIG. 6 notches 26 are spaced for at least one (1) notch 26 per quadrant of bend radius, which equates to a maximum notch spacing of 2π×OD (Outside Diameter) for UTP (Unshielded Twisted Pair) or 4π×OD (Outside Diameter) for screened cables. For example, for a UTP cable 10 with an OD of 0.225″, spacing would be at a maximum of 1.41″ between successive notches 26.

[0021] In another embodiment, it is noted that a regular periodic notch 26 spacing results in a return loss spike that may modulate and create a crosstalk spike in the signals passing through pairs 12. As such, in this arrangement, aside from the basic notch spacing advised above, the actual placement is varied slightly, from notch 26 to notch 26 about an average of the calculated distance to avoid precise repetitions. For example, if the calculated spacing is 1.41″ per notch 26, a first spacing may be 1.40, then a second spacing may be 1.42″ for an average of 1.41″.

[0022] While only certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes or equivalents will now occur to those skilled in the art. It is therefore, to be understood that this application is intended to cover all such modifications and changes that fall within the true spirit of the invention.