Abstract
A multi-fiber connector (40) that promotes physical contact with a communicating multi-fiber connector. The multi-fiber connector (40) has a connector body (44) with a front end (47) and a back end (49). The multi-fiber connector (40) also includes a ferrule (10a, 10b) with optical contacts (20a, 20b) at a front end (14a, 14b). The ferrule (10a, 10b) is spring biased toward the front end (14a, 14b) of the connector body (44). The ferrule (10a, 10b) has a pair of alignment pin openings (30a, 30b) extending into the ferrule from a front end (14a, 14b). The ferrule (10b) also has a pair of alignment pins (22) mounted within the alignment pin openings (30a, 30b). The base ends of the alignment pins (22) have a different transverse cross-sectional shape than the alignment pin openings (30a, 30b). This difference in transverse cross-sectional shapes allows the alignment pins to pivot relative to the ferrule along a major axis of the ferrule.
Claims
1. A fiber optic connector comprising: a connector body having a front end and a back end; a ferrule mounted at the front end of the connector body, the ferrule including a depth that extends from a front end to a rear end of the ferrule, the ferrule including a contact face at the front end of the ferrule, the contact face including a major dimension that extends along a major axis defined by the contact face and a minor dimension that extends along a minor axis defined by the contact face, the major and minor axes being perpendicular to one another, the ferrule defining fiber passages that extend through the depth of the ferrule from the rear end of the ferrule to the front end of the ferrule, the fiber passages being arranged in a row that extends along the major axis of the contact face, the ferrule also defining alignment pin openings that extend rearwardly from the front end of the ferrule, the alignment pin openings defining first transverse cross-sectional shapes; a spring for biasing the ferrule in a forward direction relative to the connector body; a plurality of optical fibers that extend through the fiber passages of the ferrule, the optical fibers having end faces accessible at the front end of the ferrule; and alignment pins having base end portions positioned within the alignment pin openings, the base end portions having second transverse cross-sectional shapes that are different than the first transverse cross-sectional shapes, the different first and second transverse cross-sectional shapes being relatively configured so that the ferrule provides less resistance to alignment pin pivoting along the major axis as compared to along the minor axis.
2. The multi-fiber optic connector of claim 1, wherein the first and second transverse cross-sectional shapes are relatively shaped such that a reduced contact area is provided between the alignment pins and the ferrule along the major axis as compared to along the minor axis.
3. The multi-fiber optic connector of claim 2, wherein the first transverse cross-section shapes are round and the second transverse cross-sectional shapes include flats intersected by the major axis.
4. The multi-fiber optic connector of claim 3, wherein the reduced contact area comprises a pair of oppositely-positioned cutouts.
5. The multi-fiber optic connector of claim 1, wherein the second transverse cross-sectional shape is circular and the second transverse cross-sectional shape is elongated in a direction along the major axis.
6. The multi-fiber optic connector of claim 1, wherein the alignment pins openings are positioned with the plurality of fiber passages there between.
7. The multi-fiber optic connector of claim 1, wherein the ferrule deforms to allow the alignment pins to pivot along the major axis.
8. The multi-fiber connector of claim 1, wherein spacings are provided between the base ends of the alignment pins and the ferrules along the major axis.
9. The multi-fiber connector of claim 1, wherein first and second spacings are provided on opposite sides of each alignment pin within each of the alignment pin openings, the first and second spacings being located between the base ends of the alignment pins and the ferrules and being intersected by the major axis.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective top view of a pair of multi-fiber optic ferrules in accordance with the principles of the present disclosure.
[0011] FIGS. 2A-2D show the pair of multi-fiber optic ferrules of FIG. 1, as viewed from various perspective sight lines.
[0012] FIG. 3 is a top planar view of the pair of multi-fiber optic ferrules of FIG. 1.
[0013] FIG. 4 is a side planar view of the pair of multi-fiber optic ferrules of FIG. 1.
[0014] FIG. 5A is an enlarged view of one of the alignment pins, as presented in FIG. 2A.
[0015] FIG. 5B is an enlarged view of one of the alignment pins, as presented in FIG. 2B.
[0016] FIG. 6 is a cross-sectional top view of the pair of multi-fiber optic ferrules of FIG. 1.
[0017] FIG. 7A is a cross-sectional top view of multi-fiber ferrules of the type shown in FIG. 1 in optically-mating communication. The depicted ferrules have been manufactured with perpendicularity between the alignment pins/alignment pin openings and the ferrule end faces so that effective end-to-end face contact of the ferrules is achieved without requiring pivoting between the ferrules.
[0018] FIG. 7B is a cross-sectional top view of multi-fiber ferrules of the type shown in FIG. 1 in optically-mating communication. Due to manufacturing tolerances, at least one of the depicted ferrules has been manufactured with non-perpendicularity between the alignment pins/alignment pin openings and the ferrule end faces so that absent a flexible interface between the ferrules a gap is provided between the ferrule end faces that prevents effective end-to-end face contact of the ferrules from being achieved.
[0019] FIG. 7C shows the multi-fiber ferrules of FIG. 7C pivoted relative to one another to a position where the gap between the ferrule end faces is closed so that effective end-to end face contact of the ferrules is achieved. With effective end-to-end face contact of the ferrule end faces, the end faces of the optical fibers supported by the ferrules also make end-to-end face contact such that low-loss optical connections are made between the optical fibers. The flexible pin mounting configuration incorporated into at least one of the ferrules allows the ferrules to pivot relative to one another to close the gap between the ferrule end faces.
[0020] FIG. 8 is a cross-sectional view of the multi-fiber optic ferrule of FIG. 3, as viewed along sight line B.
[0021] FIG. 9 is a cross-sectional view of another embodiment of a multi-fiber optic ferrule in accordance with the principles of the present disclosure.
[0022] FIGS. 10A-10B show perspective top views of the multi-fiber optic ferrules of FIG. 1, shown with each ferrule mounted within a respective fiber-optic connector.
DETAILED DESCRIPTION
[0023] Some aspects of this disclosure are directed to certain types of multi-fiber optic ferrules for use with fiber-optic connector and cable assemblies. In some implementations, for example as shown in FIGS. 1-4, 6 and 7A-7C, the disclosure may include a female ferrule 10a and a male ferrule 10b adapted to be coupled together. When the ferrules 10a, 10b are coupled together (i.e., mated) optical fibers supported by the female ferrule 10a are optically coupled to corresponding optical fibers supported by the male ferrule 10b. In certain examples of the present disclosure, the male ferrule 10b has an alignment pin mounting configuration that allows alignment pins mounted to the male ferrule to pivot relative to the ferrule body to compensate for physical characteristics of the ferrule (e.g., non-perpendicularity between the ferrule end face and the alignment pins or alignment pin openings) that would otherwise cause a gap to be present between the end faces of the mated ferrules 10a, 10b. Such physical characteristics can be the unintentional result of manufacturing tolerances.
[0024] In some aspects, the female ferrule 10a and the male ferrule 10b each may include a depth that extends from a front end 14a, 14b to a rear end 12a, 12b of the ferrule. In some aspects, the female ferrule 10a and the male ferrule 10b each may include a contact face 17a, 17b at the front end 14a, 14b of the ferrule. In some aspects, each contact face 17a, 17b may include a major dimension that extends along a major axis A.sub.1 defined by the contact face and a minor dimension that extends along a minor axis A.sub.2 defined by the contact face. In some aspects, the major A.sub.1 and minor A.sub.2 axes may be perpendicular to one another.
[0025] In some implementations, for example as shown in FIGS. 6-7C, the female ferrule 10a and the male ferrule 10b may each define fiber passages 19a, 19b that extend through the depth of the ferrule from the rear end 12a, 12b of the ferrule to the front end 14a, 14b of the ferrule. In some aspects, the fiber passages 19a, 19b may be arranged in a row that extends along the major axis A.sub.1 of the contact face. In some aspects, the female ferrule 10a and the male ferrule 10b each may include a plurality of optical fibers 21a, 21b that extend through the fiber passages 19a, 19b. Example optical fibers 21a, 21b include material (e.g., a glass core surrounded by a glass cladding layer) that transmits optical information/signals. In some aspects, the optical fibers 21a, 21b may include end faces 20a, 20b (FIGS. 5A-5B) that are accessible at the contact faces at the front ends 14a, 14b of the ferrules 10a, 10b. In use, the example optical fiber end faces 20a, 20b may contact each other (FIGS. 7A, 7C) to transmit optical signals between the optical fibers 21a, 21b.
[0026] In some implementations, for example as shown in FIGS. 6-7C, the female ferrule 10a and the male ferrule 10b each may defme a pair of alignment pin openings 30a, 30b. In some aspects, the alignment pin openings 30a, 30b may extend rearwardly from contact face at the front end 14a, 14b of the ferrule 10a, 10b. As depicted, the optical fibers 19a, 19b of each ferrule 10a, 10b may be positioned between each pair of alignment feature openings 30a, 30b.
[0027] In some implementations, for example as shown in FIGS. 1-9, the alignment pin openings 30a, 30b of the ferrules 10a, 10b may define a first transverse cross-sectional shape and/or size. Example first transverse cross-sectional shapes may include circular, substantially circular, oblong, etc. In some aspects, the alignment pin openings 30a, 30b for each ferrule 10a, 10b may define substantially identical transverse cross-sectional shapes and/or sizes.
[0028] In some implementations, for example as shown in FIGS. 1-9, the male ferrule 10b may include a pair of alignment pins 22, for example a pair of alignment pins 22 with distal point contacts 34 that can be rounded distal tips, and proximal base end portions 36 positioned and supported within the alignment pin openings 30b. The proximal base end portions 36 may be permanently secured within the alignment pin openings 30b. In some aspects, the distal point contacts 34 may have a different transverse cross-sectional shape from the base end portions 36. For example, as depicted, the distal point contacts 34 may have a transverse cross-sectional shape that is substantially similar to the first transverse cross sectional shape of the alignment pin openings 30a, 30b (e.g., circular). In some aspects, the base end portions 36 may have a second transverse cross-sectional shape and/or size that is different than the first transverse cross-sectional shape and/or size of the alignment pin openings 30a, 30b. Example second transverse cross-sectional shapes of the base end portions 36 may be non-circular. In certain examples, transverse cross-sectional shapes of the base end portions 36 may include flat sides (i.e., opposite parallel cutouts 32) that extend between rounded ends. Since the alignment pin openings 30b have round transverse cross-sectional shapes, the flat sides provide reduced contact areas with the body of the ferrule. In other words, the flat sides do not contact the ferrule since spacing is provided between the flat sides of the base end portions of the alignment pins 22 and the round contour of the alignment pin openings 30b.
[0029] In some implementations, for example as shown in FIGS. 1-8, an example first transverse cross-sectional shape of the pair of alignment pin openings 30a, 30b may be circular, and a corresponding example second transverse cross-sectional shape of the pair of base end portions 36 may be substantially circular with a reduced contact area, for example parallel cutouts 32 (i.e., flats) on opposing sides.
[0030] In other implementations of the disclosure, for example as shown in FIG. 9, an example first transverse cross-sectional shape of alignment openings 100 may be oblong, and a corresponding example second transverse cross-sectional shape of alignment pin base end portions 102 may have a circular shape.
[0031] In some implementations, the different example first and second transverse cross-sectional shapes and/or sizes may be relatively configured so that the ferrule 10b provides less resistance to the pins 22 (e.g., pins) pivoting along the major axis A.sub.1 as compared to along the minor axis A.sub.2. In the embodiment of FIG. 8, the interrelation between the flats 32 of the base end portions of the pins 22 and the round alignment pin openings 30b provide less contact area between the base ends of the pins 22 and the ferrule 10b along the major axis A.sub.1 as compared to along the minor axis A.sub.2. Thus, less material of the ferrule 10b opposes pivoting of the pins 22 relative to the ferrule 10b along the major axis A.sub.1 as compared to along the minor axis A.sub.2. Because a relatively small amount of ferrule material supports the pins along the major axis A.sub.1, such material will deform at relatively low forces to allow the pins 22 to pivot along the major axis A.sub.1. In the embodiment of FIG. 9, the interrelationship between the elongated shape of the alignment pin openings 100 and the round shape of the base ends of the pins 102 provide less contact area between the base ends of the pins 102 and the ferrule 10 along the major axis A.sub.l as compared to along the minor axis A.sub.2. Thus, similar to the embodiment of FIG. 8, the pins 102 can pivot more easily relative to the ferrule along the major axis A.sub.1 as compared to along the minor axis A.sub.2.
[0032] In some aspects, the reduced contact area of the alignment pins 22 weakens the stiffness in the direction along the major axis A.sub.1. In some aspects, the reduced contact area of the alignment features 22 causes the distal tips 34 to be point contacts within the female ferrule alignment openings 30 when the example ferrules 10a, 10b are in contact engagement.
[0033] In accordance with some implementations, for example as shown in FIGS. 10A and 10B, the disclosure may include a fiber optic connector 40 that includes a connector body 44 with a front end 47 and a back end 49. In some aspects, each example ferrule 10a, 10b may be mounted at the front end 47 of one connector body 44. In some aspects, a spring 45 may bias the example ferrule 10a, 10b in a forward direction relative to the connector body 44.
[0034] In a multi-fiber connector, ideally perpendicularity is provided between the alignment pins/alignment pin openings and the end faces of the ferrules. When such perpendicularity exists, then effective end-to-end contact is provided between the end faces of mated ferrules and physical contact is provided between all of the optical fibers intended to be optically coupled together by the mated multi-fiber optical connectors (see FIG. 7A). In the situation of FIG. 7A, perpendicularity exits and three is no need to pivot the ferrules relative to one another to ensure that physical contact is provided between the end faces of the all the optical fibers.
[0035] Due to manufacturing tolerances, perpendicularity is not always present between the alignment pins/alignment pin openings and the end faces of the ferrules. When a lack of perpendicularity exists, when two multi-fiber ferrules are mated, an angular gap exists between the end faces of the mated multi-fiber ferrules (see FIG. 7B). Due to the relatively long length of the ferrules along the major axis A.sub.1, the gap is exaggerated at one end of the row of optical fibers thereby causing a substantial spacing between the end faces of the optical fibers located at that end (i.e., effective end-to-end contact is not provided between the end faces of the ferrules). This type of spacing can cause substantial attenuation losses. To correct this issue, resilient pin mounting configurations in accordance with the principles of the present disclosure allows the mated ferrules to pivot relative to one another to close the gap (see FIG. 7C) and provide effective end-to-end contact between the ferrule end faces. The reduced pin support provided along the major axis A.sub.1 allows the material of the male ferrule to deform when the ferrules 10a, 10b are pressed together by the springs 45 thereby allowing the ferrules to move from the position of FIG. 7B to the position of FIG. 7C. Thus, the spring force provided by the springs 45 is greater than the force required to deform the material of the ferrule supporting the base ends of the alignment pins along the major axis A.sub.1. Thus, the springs 45 provide the force needed to pivot the ferrules 10a, 10b from the position of FIG. 7B to the position of FIG. 7C.
[0036] It will be appreciated that in the position of FIG. 7C, pivoting of the ferrules 10a, 10b causes the ferrules 10a, 10b to be slightly angularly misaligned (i.e., the central longitudinal axes of the ferrules are slightly angled relative to one another). Despite the slight angular misalignment, the physical contact between the optical fibers provided in this orientation results in a low-loss optical coupling.
[0037] It is noted that the pins can be pivoted more easily along the major axis A.sub.1 as compared to along the minor axis A.sub.2. The ability to pivot along the major axis A.sub.1 as compared to the minor axis A.sub.2 is important because the relatively long length of the ferrules on the major axis A.sub.1 exaggerates physical contact issues related to non-perpendicularity. Thus, slight lacks of non-perpendicularity along the major axis A.sub.1 can result in substantial spacings between optical fibers. This is less of an issue along the relatively short minor axis A.sub.2 so the ability to pivot the ferrules in this orientation is less significant.
PARTS LIST
[0038] 10a—Female ferrule
[0039] 10b—Male ferrule
[0040] 12a—Female ferrule rear end
[0041] 12b—Male ferrule rear end
[0042] 14a—Female ferrule front end
[0043] 14b—Male ferrule front end
[0044] 17a—Female ferrule contact face
[0045] 17b—Male ferrule contact face
[0046] 19a—Female ferrule fiber passage
[0047] 19b—Male ferrule fiber passage
[0048] 20a—Female ferrule fiber end face
[0049] 20b—Male ferrule fiber end face
[0050] 21a—Female ferrule optical fiber
[0051] 21b—Male ferrule optical fiber
[0052] 22—Alignment pin
[0053] 30a—Female ferrule alignment pin opening
[0054] 30b—Male ferrule alignment pin opening
[0055] 32—Pin flat/cutaway
[0056] 34—Pin distal point contact
[0057] 36—Pin proximal base end portion
[0058] 40—Fiber optic connector
[0059] 44—Fiber optic connector body
[0060] 45—Spring
[0061] 47—Fiber optic connector body front end
[0062] 49—Fiber optic connector body back end
[0063] 100—Oblong alignment pin opening
[0064] 102—Circular pin base end portion
