Abstract
A connection arrangement is provided for connecting an armored cable to a connection piece. The arrangement has a ferrule for fitting onto the end of the armored cable, that has an abutment flange, a washer and a threaded region. The threaded region has at least a portion threaded according to a first thread standard. A lock nut is configured to fit over the armored cable, and to connect with a nut thread on the connection piece. The lock nut and the connection piece are configured to compress the ferrule therebetween forming a watertight connection. An armor of the armored cable has a least a portion of the armor threaded to match the first thread standard.
Claims
1. A connection arrangement for connecting an armored cable to a connection piece, said connection arrangement comprising: a ferrule, for fitting onto the end of the armored cable, said ferrule having an abutment flange, a washer and a threaded region, wherein the threaded region has at least a portion threaded according to a first thread standard; and a lock nut, configured to fit over said armored cable, and to connect with a nut thread on said connection piece, said lock nut and said connection piece configured to compress said ferrule therebetween forming a watertight connection, wherein an armor of said armored cable has a least a portion of said armor threaded to match said first thread standard.
2. The connection arrangement as claimed in claim 1, wherein said first thread standard of said threaded region of said ferrule is an NPT thread standard (ANSI/ASME B1.20.1), and wherein said armor of said armored cable is threaded to a standard AC armor pitch, and wherein said armor of said armored cable has a modified armor pitch of said NPT thread standard (ANSI/ASME B1.20.1) at a region of connection with said threaded region of said ferrule.
3. The connection arrangement as claimed in claim 1, and wherein said armor of said armored cable has a modified armor pitch of said NPT thread standard (ANSI/ASME B1.20.1) over at least some portion of the length of said armored cable.
4. The connection arrangement as claimed in claim 1, wherein said armor of said armored cable is threaded to a standard AC armor pitch, and wherein said first thread standard of said threaded region of said ferrule is said standard AC armor pitch.
5. The armored cable as claimed in claim 1, further comprising a polymer jacket over said armor of said armored cable.
6. The armored cable as claimed in claim 5, wherein said polymer jacket is water-tight.
7. The armored cable as claimed in claim 1, wherein said cable is any one of a twisted pair cable, a fiber optic cable or a hybrid cable.
8. The armored cable as claimed in claim 1, wherein said armor of said armored cable, is selected from any one of: AC armor, interlocking aluminum armor, helical steel armor, corrugated armor, and helical plastic armor; any of which may exhibit a standard AC armor pitch.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention can be best understood through the following description and accompanying drawing, wherein:
[0017] FIG. 1 is a prior art LFMC connector;
[0018] FIG. 2 is a prior art table of NPT thread standards;
[0019] FIG. 3 is a prior art water-tight cable gland;
[0020] FIG. 4 illustrates a modified water-tight jacketed armored twisted-pair, fiber optic cable, or hybrid cable with an LFMC connector, in accordance with one embodiment;
[0021] FIG. 5 illustrates a water-tight jacketed armored twisted-pair, fiber optic, or hybrid cable, with a modified LFMC connector, in accordance with one embodiment;
[0022] FIGS. 6A and 6B illustrates an adapter ferrule, in accordance with one embodiment;
[0023] FIG. 6C illustrates the adapter ferrule of FIGS. 6A and 6B in cross-section, in accordance with one embodiment
[0024] FIG. 7 illustrates a water-tight jacketed armored twisted-pair, fiber optic, or hybrid cable, with an LFMC connector and the adapter ferrule of FIGS. 6A-6C, in accordance with one embodiment.
DETAILED DESCRIPTION
[0025] In one embodiment as shown in FIG. 4 an exemplary LFMC connector 10 is shown having a connection piece 12, which is illustrated as a 90 degree elbow connection, however any shape connection piece 12 can be used (e.g. straight, offset, 45 degree, 30 degree, etc . . . ). Connection piece 12 has a nut thread region 14 for accepting a corresponding lock nut 16. The connector 10 has a ferrule 20 that fits between connection piece 12 and lock nut 16. Ferrule 20 has a threaded region 22 for accepting armor and holding a connection therewith. In this embodiment, threaded region 22 is threaded to its ordinary prior art NPT standards. Ferrule 20 further has an abutment flange 24 and a washer 26. When lock nut 16 is threaded onto threaded region 14, it compresses washer 26 against the inside of abutment flange 24 and compresses the outside of abutment flange 24 against an interior face of connector 10 (as described in more detail below). These two areas of compression create the water-tight seal with the armor 32 and physical bonding. If the connection piece 12, ferrule 20 and armor 34 are metallic, this creates an electrically conductive path for the purposes of bonding to earth. If the enclosure is grounded, then so is the cable armor.
[0026] As shown in FIG. 4, a fiber optic, twisted-pair, or hybrid cable 30 is shown having an armor 32, such as AC type aluminum helical armor, and a water-tight polymer jacket 34 thereover. It is noted that armor 32 can be interlocking aluminum, steel, corrugated, plastic, etc . . . , but for the purposes in this embodiment, armor 32 has a thread/twist rate that is modified to match the corresponding NPT type thread scale on threaded region 22 of ferrule 20. In a variation, armor 32 can maintain such modified thread/twist rate over the entire length of cable 30, or it can be only a segment of cable 30 that exhibits such modified pitch. In another variation, an empty armor tube 32 can be provided (without fibers or conductors therein), also exhibiting the modified thread/twist rate over a portion or all of the empty armor tube.
[0027] Using the first variation of armor 32 that maintains such modified thread/twist rate over the entire length of cable 30 as shown in FIG. 4, cable 30 and armor 32 is fit through lock-nut 16 and the modified pitch/thread is screwed onto threaded region 22′ of ferrule 20, and pressed against washer 26 into abutment flange 24. Thereafter one would screw lock nut 16 on nut thread 14 of connection piece 12 to tighten down the entire connector 10 into a water-tight connection for cable 30.
[0028] In another embodiment as shown in FIG. 5 connector 10 has the same connection piece 12, nut thread region 14 and lock nut 16 as well as ferrule 20, threaded region 22, abutment flange 24, and washer 26. Likewise FIG. 5 also shows fiber optic, twisted-pair, or hybrid cable 30 is shown having an armor 32′ and a water-tight polymer jacket 34 thereover.
[0029] However, unlike FIG. 4, in this embodiment, armor 32′ has a thread/twist rate that is ordinary AC type pitch and thread setting, but threaded region 22′ on ferrule 20 is modified to match the corresponding AC type pitch. In any case, similar to FIG. 4, after armor 32′ is connected to threaded region 22′ screw lock nut 16 is screwed onto nut thread 14 of connection piece 12, it compresses washer 26 against the inside of abutment flange 24 and compresses the outside of abutment flange 24 against an interior face of connector 10.
[0030] In another embodiment as shown in FIGS. 6A-6C, and 7, an adapter ferrule 50 is provided having a smaller diameter cylinder 52 and a larger diameter cylinder 54 with a threaded recess 56 therebetween. The inside of threaded recess 56 maintains a threading 57 and the inside of smaller diameter cylinder 52 has an inside thread 60 matching the pitch and lead of AC armor 32′ of cable 30. As shown in FIG. 6C, inside thread 60 of small cylinder 52 is configured to accept the helical grooves of armor 32′ once cable 30 is screwed therein It is noted that inside thread 60, configured to mate with the helical grooves of armor 32′ in a manner that essentially locks the threads of inside thread 60 “inside” of armor 32′, i.e. between armor 32′ and the cable elements inside).
[0031] As shown in FIGS. 6A-6C and FIG. 7, an outside diameter of smaller cylinder 52 is dimensioned to fit within threaded region 22 of ferrule 20 so that it can fit therewithin.
[0032] Thus, as shown in FIG. 7, once cable 30 is connected to adapter ferrule 50 as indicated above, threaded recess 56 with threads 57 of adapter ferrule 50 is fitted over the outside NPT type threading of thread region 22 of ferrule 20 connecting ferrule 20 with adapter ferrule 50 (and cable 30). This allows threads 57 in threaded recess 56, which are matched to the pitch and dimensions of threaded region 22 to be mated with ferrule 20, so that lock nut 16 and screw onto threads 14 of connector, with adapter ferrule 50 fit entirely within the enclosure with ferrule 20. The overall outer dimension of larger diameter cylinder 54 of adapter ferrule is such that it does not interfere with the ordinary operation of lock nut 16 fitting onto nut threads 14 of connection piece 12 to complete the water-tight seal to cable 30.
[0033] Essentially, adapter ferrule 50 allows a standard twist rate AC type armor 32′ to be engaged and connected to existing NPT threaded ferrule 20 without modification to the threading of either threaded region 22 or armor 32′.
[0034] Regarding the above embodiments of FIG. 4, 5, 6A-6C, and 7, such an arrangement is presented as a water-tight connection armored cable, but it may also be used for liquid-tight flexible non-metallic conduit (LFNC).
[0035] 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.
