Crimp for an optical cable connector

Abstract

A crimp comprises a hollow crimp body that is open at each end and includes, a first end, a first crushable crimp tube for crimping onto a connector; and at a second end a second crushable crimp tube for crimping onto a cable, the portion of the crimp between the said ends including a recess for engagement by a closure housing.

Claims

1. A one-piece crimp for an optical cable connector, the one-piece crimp comprising: a hollow body extending from a first open end to a second open end; a first crushable crimp tube adjoining the first open end; a second crushable crimp tube adjoining the second open end; an enlarged portion extending between the first crushable crimp tube and the second crushable crimp tube, the enlarged portion having a dimension greater than that of the crushable crimp tubes; and a recess on a periphery of the enlarged portion, wherein the recess is an encircling groove of rectangular-channel cross section.

2. The one-piece crimp of claim 1, wherein the hollow body is cylindrical.

3. The one-piece crimp of claim 1, wherein the first and the second crushable crimp tubes are each cylindrical.

4. The one-piece crimp of claim 3, wherein the first and the second crushable crimp tubes are each of a same diameter.

5. The one-piece crimp of claim 4, wherein the first and the second crushable crimp tubes are each of a same length.

6. The one-piece crimp of claim 1, wherein the recess is positioned nearer to the second crushable crimp tube than the first crushable crimp tube.

7. The one-piece crimp of claim 1, wherein the first crushable crimp tube is configured for crimping onto a spigot of the optical cable connector.

8. The one-piece crimp of claim 1, wherein the first crushable crimp tube is further configured for crimping reinforcing fibers of an optical cable to the spigot of the optical cable connector.

9. The one-piece crimp of claim 1, wherein the second crushable crimp tube is configured for crimping onto an optical cable.

10. The one-piece crimp of claim 1, wherein the recess is configured for engagement by a closure housing.

11. The one-piece crimp of claim 1, wherein the hollow body is configured to receive an optical cable.

12. A method of securing an optical cable to an optical cable connector, the method comprising: providing the optical cable; providing the optical cable connector; providing a one-piece crimp including: a hollow body extending from a first open end to a second open end; a first crushable crimp tube adjoining the first open end; a second crushable crimp tube adjoining the second open end; an enlarged portion extending between the first crushable crimp tube and the second crushable crimp tube; and a recess on a periphery of the enlarged portion; inserting the optical cable through the hollow body so that the optical cable protrudes at the first open end and the second open end; and inserting the one-piece crimp into an aperture of a closure housing so that a part of the closure housing engages the recess of the one-piece crimp so as to prevent relative movement between the one-piece crimp and the closure housing.

13. The method of claim 12, further comprising advancing the one-piece crimp so that the first crushable crimp tube overlies a spigot of the optical cable connector.

14. The method of claim 13, further comprising crimping the first crushable crimp tube onto the spigot so as to retain the one-piece crimp on the spigot.

15. The method of claim 14, further comprising: prior to crimping the first crushable crimp tube onto the spigot: removing a jacket of the optical cable to expose a core and reinforcement fibers thereof; inserting the core into the spigot of the optical cable connector; and arranging the reinforcement fibers about the spigot.

16. The method of claim 15, further comprising crimping the second crushable crimp tube onto an exterior of the optical cable.

17. An optical cable connector assembly comprising: a crimp including: a hollow body extending from a first open end to a second open end; a first crushable crimp tube adjoining the first open end; a second crushable crimp tube adjoining the second open end; an enlarged portion extending between the first crushable crimp tube and the second crushable crimp tube; and a recess on a periphery of the enlarged portion; an optical cable including a jacket, a core, and reinforcement fibers; and an optical cable connector including a spigot and a closure housing; wherein the reinforcement fibers are arranged about the spigot; wherein the first crushable crimp tube overlies and is crimped to the reinforcement fibers and the spigot and thereby retains the reinforcement fibers; wherein the second crushable crimp tube is crimped onto an exterior of the jacket of the optical cable; wherein an aperture of the closure housing receives the crimp; and wherein a part of the closure housing engages the recess of the crimp and thereby prevents relative movement between the crimp and the closure housing.

Description

(1) There now follows a description of a preferred embodiment of the invention, by way of non-limiting example, with reference being made to the accompanying figures in which:

(2) FIG. 1 shows a prior art crimp;

(3) FIG. 2 is a side-elevational, partially longitudinally sectioned view of a crimp according to the invention;

(4) FIG. 3 shows schematically how such a crimp is connectable to a per se known connector; and

(5) FIG. 4 shows the crimp of FIGS. 2 and 3 connected to a connector, and also illustrates schematically the engagement of a wall with a recess defined in the crimp.

(6) Referring to FIGS. 2 to 4, there is shown a crimp 30 according to the invention.

(7) Crimp 30 is intended for use with an optical cable connector, especially (but not exclusively) an optical drop cable connector.

(8) Crimp 30 includes a hollow, cylindrical crimp body 31 that is formed eg. by machining, pressing, forging or sintering from a metal providing appropriate crimp strength and crushability characteristics.

(9) Any of a range of crushable metals is suitable for use in manufacture of the crimp, including but not limited to Brass and other Copper alloys.

(10) Crimp body 31 is open at each end 32, 33 as best seen in FIGS. 2 and 3.

(11) At first end 32 crimp 30 defines a first, hollow, cylindrical, comparatively thin-walled crushable crimp tube 34. Crimp tube 34 is intended for crimping onto a spigot 13 (FIG. 3) of a connector 10 which is known per se in the prior art.

(12) At second end 33 crimp 30 defines a second hollow, cylindrical, crushable metal crimp tube 36 that is intended for crimping onto the jacket of an optical fibre cable.

(13) The portion of crimp 30 lying between ends 32 and 33 includes a recess 37 that is intended for engagement by a closure housing 38 (FIG. 4).

(14) The portion 39 of the crimp extending between the crimp tube 34, 36 is itself cylindrical.

(15) The diameter of portion 39 is greater than that of either crimp tube 34, 36. In practice the crimp tubes are, as shown by FIG. 2, each of generally the same dimensions as each other.

(16) The recess 37 is in the embodiment shown a groove formed in the periphery of portion 39. The groove is of rectangular-channel cross-section, and as shown by the drawings extends about the whole periphery of the portion 39.

(17) Groove 37 thus is readily formed by machining the cylindrical portion 39 using eg. a lathe or comparable tool.

(18) Recess 37 is offset towards one end of portion 39. This allows for spacing of the engagement location of the crimp 30 with a closure wall 38 away from the vicinity of the connector 10.

(19) As noted herein, a further advantage of forming the recess 37 as an encircling peripheral groove in a cylindrical component is that the crimp 30 may be used without concern for its angular orientation with respect to its longitudinal axis.

(20) FIGS. 3 and 4 show the use of the crimp 30 to connect a cable such as an optical drop cable 17 to a connector 10.

(21) The cable 17 is prepared in the same way as in the prior art (ie. as shown in FIG. 1).

(22) The result of such preparation is for the core assembly 19 of the cable and the reinforcing Kevlar fibres 21 to be exposed a short distance beyond the cut-away cable jacket 18, following threading of the cable through the hollow interior of the crimp 30.

(23) Thereafter it is necessary simply to insert the core assembly 19 into the spigot 13; arrange the reinforcing fibres 21 about the exterior of the spigot 13; advance the crimp tube 34 to encircle the spigot and fibres; crush the first crimp tube 34 onto the spigot 13; and crush the second crimp tube 36 onto the cable jacket 18 at a location spaced a short distance away from the connector 10.

(24) FIG. 4 shows the crimp and connector assembly following completion of such steps.

(25) Subsequently the crimp 30 may be located with its recess 37 received in a further recess, groove or aperture defined in a wall 38 of eg. a container housing or an equipment cabinet.

(26) Longitudinal strain induced in the cable 17 (as signified by the words “cable pull” in FIG. 4) is transferred to the wall 38, thereby isolating the vicinity of the connector 10, the spigot 13 and first crimp tube 34 from such strain.

(27) Consequently the crimp of the invention permits the cable 17 to withstand very significantly greater tensile forces, without causing detachment of the connector 10 from an associated socket, than has been possible using the prior art arrangements. Pull forces of up to 100-150N can readily be resisted.