Duplex optical fiber connector

• US 4,787,706 A
• Filed: 02/03/1987
• Issued: 11/29/1988
• Est. Priority Date: 02/03/1987
• Status: Expired due to Term

• Current Assignee: Fitel USA Corporation
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Carlisle, Arthur W., Cannon, Thomas C. Jr., Darden, Bruce V.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): HEALY, BRIAN
• Application Number:
  US07/010,508
• Time in Patent Office: 665 Days
• Field of Search: 350/96.20, 350/96.21, 350/96.22, 350/96.23, 350/96.16
• US Class Current: 385/59
• CPC Class Codes: G02B 6/3831 comprising a keying element on the plug or adapter, e.g. to forbid wrong connection keying element on the ferrule G02B6/3851; keying element for electrical coupling H01R13/64
• CPC Class Codes: G02B 6/3849 using mechanical protective elements, e.g. caps, hoods, sealing membranes G02B6/3816 takes precedence; provisionally see H01R13/44
• CPC Class Codes: G02B 6/3869 Mounting ferrules to connector body, i.e. plugs
• CPC Class Codes: G02B 6/3878 comprising a plurality of ferrules, branching and break-out means
• CPC Class Codes: G02B 6/3888 Protection from over-extension or over-compression
• CPC Class Codes: G02B 6/3893 Push-pull type, e.g. snap-in, push-on
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures
• CPC Class Codes: G02B 6/4292 the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements

Abstract

A duplex optical fiber connector (20) includes a housing (21) having a cable entrance end and a plug end. At the cable entrance end, an optical fiber cable (23) which includes two individually buffered optical fibers (25--25), strength member yarn (29) and a plastic jacket is routed into a flanged end of a bushing (45) having a tapered passageway therethrough. The bushing is supported in a base (22) of the housing. The jacket is removed from the portion of the cable which extends from the cable entrance end to the plug end and the yarn is positioned between two conformable, truncated conically shaped, substantially smooth surfaces which define the passageway of the bushing and a truncated conically shaped wedge (50) which is received in the passageway. The wedge includes a bore through which the optical fibers extend. This locking arrangement in which the yarn makes no retroflexed turns is self-enhancing when tensile forces are applied to the cable. At the plug end are secured two plugs (70--70) each terminating one of the optical fibers. Each plug is spring-loaded and further, end portions of the plugs which protrude beyond the connector housing are protected by a bumper (90) which also is spring-loaded and which is moved inwardly when the connector is assembled to another. A cover (52) is assembled to the base to complete the housing and to secure the force-transfer facilities and plugs therein.

Claims

1. A duplex optical fiber connector for terminating two optical fibers of a cable and being adapted to be joined to another connector, said duplex connector comprising:

a housing which comprises first and second mating portions and which includes a cable entrance end and a plug end;

force transfer means adapted to be disposed adjacent to said cable entrance end and through which the optical fibers extend for transferring tensile forces applied to the cable to the housing;

plug means adapted to be associated with each of the optical fibers and disposed within said housing adjacent to said plug end of said housing a predetermined distance from said force transfer means, each said plug means including a plug adapted to be associated with and to terminate one of the optical fibers of the cable, and protruding from said plug end of said housing; and

protective means mounted on said housing in which said plug means are disposed for reciprocal movement with respect to said housing for protecting end portions of the plugs which protrude from said housing and which is caused to be retracted when said connector is joined to another connector to expose said plugs and allow them to be operatively connected to plugs of the other connector.

2. The duplex optical fiber connector of claim 1, wherein said protective means includes bumper means mounted for reciprocal movement with respect to said housing and being effective in a first position for protecting ends of said plugs and in a second position being retracted to allow ends of the plugs to engage ends of the plugs of another duplex connector, and wherein said force transfer means is effective to clamp non-metallic filamentary strength members of the cable and includes two conformable substantially smooth conically shaped surfaces which diverge in a direction from said cable entrance end of said housing toward said plug end such that any angle between successive portions of length of the strength members in engagement with and adjacent to said surfaces is at least a predetermined value.

3. The duplex optical fiber connector of claim 2, wherein said plug means includes an end portion which includes two spaced collars and a passageway therethrough and a plug which extends through and from said end portion and which includes a shoulder fixed to an end of said plug, and an associated compression spring which is disposed about said plug and which engages one of said spaced collars and said shoulder, each of said plug means adapted to be mounted in one of said mating portions of said housing, said housing including opposing lips which are received between said spaced collars to hold said plug means therein such that forces applied to each said plug causes the associated spring to be compressed and said plug to be moved through said passageway in said end portion of said plug means and into said housing.

4. The duplex optical fiber connector of claim 2, wherein said housing includes two flexible sidearms each being attached to said housing adjacent to said plug end of said housing and having a free end adjacent to said cable end, each of said sidearms including a latching nub which extends outwardly and which is adapted to be received in a window of a coupling into which said connector is adapted to be received to become operatively connected to another said connector.

5. The duplex optical fiber connector of claim 2, wherein said bumper means includes an end portion which extends parallel to an end face of the connector and two depending side portions each being received in a groove of a sidewall of one of the mating portions of said housing, said bumper means also including a post which extends inwardly into said housing from said end portion and a spring disposed between an end of said post and an abutment within said one portion of said housing, said end portion of said bumper means also including two spaced openings each being aligned with one of said plugs and spaced therefrom so that the end portion of each said plug is protected from impact and so that each plug may be moved through its associated opening to provide a connection with another plug.

6. The duplex connector of claim 5, which also includes spring means which is disposed in said housing and which in an unoperated condition engages a portion of said post of said bumper means and is effective to prevent retrograde movement of said bumper means and which in an operated condition is disengaged from said bumper means to allow said bumper means to be moved toward said cable end of said connector to expose said plugs.

7. The duplex connector of claim 6, wherein said housing includes a cover and a base and said spring means is supported in said base with spaced ramp portions extending through openings in said cover and wherein said post of said bumper means includes a collar disposed adjacent to said abutment, said ramp portions being adapted to be engaged by camming portions which extend into a cavity of a coupling in which a plug end portion of said connector is adapted to be received to cam said ramp portions inwardly and move tabs extending from legs, which connect said ramp portions which support portions adjacent to said base, toward said base to disengage said tabs from the collar which is disposed about an inner end of said post so that when said end portion of said bumper means engages the coupling, said bumper means is allowed to be moved toward said cable end of said housing upon further movement of said connector into the coupling cavity.

8. The duplex connector of claim 1, wherein said protective means includes a hood which is slidably mounted on said housing, said hood being adapted to receive an end portion of a coupling having a center portion into which said plugs are adapted to extend to operatively connect to plugs of another connector which is received in the other end of the coupling, said housing including two sidearms each being attached to said cable end of said housing and having a free end which includes a latching nub adjacent to said plug end, said hood being adapted to snap-lock into an extended position to protect said plugs and in a retracted position adapted to allow said latching nubs of said arms to become disposed in windows of the coupling into which two of said duplex connectors are adapted to be assembled to connect associated optical fibers thereof.

9. The connector of claim 2, wherein said force transfer means includes

a bushing which is disposed in said housing and which includes a tapered passageway which is defined by a substantially smooth surface;

and

a truncated conically shaped wedging member which is received in said passageway of said bushing and which has an outer surface which is substantially smooth and comformable to said surface of said bushing, said bushing and said wedging member cooperating to receive an end of the cable in a small diameter portion of said passageway with the non-metallic strength members being disposed between said surface of said bushing and said outer surface of said wedging member, said wedging member having a longitudinally extending bore through which optical fibers of the cable extend.

10. The connector of claim 9, wherein a line disposed on the surface of the wedging member and disposed in a plane that passes through the longitudinal axis of the wedging member makes an angle of about 1.5 degrees with the longitudinal axis of the wedging member.

11. A terminated optical fiber cable, which comprises:

an optical fiber cable which includes two individually buffered optical fibers, a plurality of non-metallic strength members and a jacket which encloses the two optical fibers; and

a duplex optical fiber connector terminating said cable, said connector comprising;

a housing which includes a base and a cover mated with said base and which includes a plug end and a cable input end;

force transfer means supported in said base and including conformable conically shaped surfaces which diverge in a direction from said cable input end and between which are captured portions of said strength members with small diameter portions of each conically shaped surface being oriented toward said cable input end of said housing to cause the strength members upon initial engagement with said force transfer means to be in engagement with said small diameter portions, such that any angle between successive portions of length of the strength members in engagement with and adjacent to said surfaces is at least a predetermined value;

plug means disposed in said housing adjacent to said plug end thereof, said plug means including two plugs each of which terminates one of the optical fibers of the cable for connecting the terminated optical fibers to other light paths disposed in apparatus to which said housing is adapted to be connected; and

reciprocally mounted means mounted on said housing for protecting said plug means prior to interconnecting said plug means with other light paths.

12. The terminated optical fiber cable of claim 11, wherein said plug means includes an end portion which includes two spaced collars and a passageway therethrough and a plug which extends through and from said end portion and which includes a shoulder fixed to an end of said plug, and an associated compression spring which is disposed about said plug and which engages one of said spaced collars and said shoulder, each of said plug means mounted in one of said mating portions of said housing, said housing including opposing lips which are received between said spaced collars to hold said plug means therein such that forces applied to each said plug cause the associated spring to be compressed and said plug to be moved through said passageway in said end portion of said plug means and into said housing.

13. The terminated optical fiber cable of claim 12, wherein said housing includes two flexible sidearms each being attached to said housing adjacent to said plug end of said housing and having a free end adjacent to said cable end, each of said sidearms including a latching nub which extends outwardly and which is adapted to be received in a window of a coupling into which said connector is adapted to be received to become operatively connected to another said connector.

14. The terminated optical fiber cable of claim 13, wherein said means for protecting said plug means includes bumper means which includes an end portion which extends parallel to an end face of the connector and two depending side portions each being received in a groove of a sidewall of one of the mating portions of said housing, said bumper means also including a post which extends inwardly into said housing from said end portion and a spring disposed between an end of said post and an abutment within said one portion of said housing, said end portion of said bumper means also including two spaced openings each being aligned with one of said plugs and spaced therefrom so that the end portion of each said plug is protected from impact and so that each plug may be moved through its associated opening to provide a connection with another plug.

15. The terminated optical fiber cable of claim 14, wherein said housing includes spring means disposed in said housing, said spring means in an unoperated condition engaging said bumper means to prevent retrograde movement of said bumper means and which in an operated condition is disengaged from said bumper means to allow said bumper means to be moved toward said cable end of said connector to expose said plugs, said spring means including portions supported in said base, and ramp portions extending through openings in said cover, said ramp portions adapted to be engaged by camming portions which extend into a cavity of a coupling into which a plug end portion of said connector is adapted to be received to cam said ramp portions inwardly and move tabs extending from legs, which connect said ramp portions with support portions adjacent to said base, toward said base to disengage said tabs from a collar which is disposed about an inner end of said post so that when said end portion of said bumper means engages said coupling, said bumper means is allowed to be moved toward said cable end of said housing upon further movement of said connector into the coupling cavity.

16. The terminated optical fiber cable of claim 15, wherein wherein said force transfer means includes

a bushing which is disposed in said housing and which includes a tapered passageway which is defined by a substantially smooth surface;

and

a truncated conically shaped wedging member which is received in said passageway of said bushing and which has an outer surface which is substantially smooth and conformable to said surface of said bushing, said bushing and said wedging member cooperating to hold an end of the cable in a small diameter portion of said passageway with the non-metallic strength members being disposed between said surface of said bushing and said outer surface of said wedging member to cause tensile loads applied to the cable to be transferred to the bushing to prevent damage to the optical fibers which are terminated by said plug means, said wedging member having a longitudinally extending bore through which optical fibers of the cable extend.

17. The terminated optical fiber cable of claim 16, wherein a line disposed on the surface of the wedging member and disposed in a plane that passes through a longitudinal axis of the wedging member makes an angle of about 1.5 degrees with the longitudinal axis of the wedging member.

18. An optical fiber connection system for interconnecting a terminated optical fiber cable, which comprises an optical fiber cable which includes two individually buffered optical fibers, a plurality of non-metallic strength members and a jacket which encloses the two optical fibers, with other light paths, said system comprising;

a duplex optical fiber connector which comprises;

a housing which includes a base and a cover mated with said base and which includes a plug end and a cable input end;

force transfer means supported in said base and including conformable conically shaped surfaces between which are adapted to be captured portions of said strength member system with small diameter portions of each conically shaped surface being oriented toward said cable input end of said housing to cause the strength members upon initial engagement with said force transfer means to be in engagement with said small diameter portions, such that any angle between successive portions of length of the strength members in engagement with and adjacent to said surfaces is at least a predetermined value;

plug means disposed in said housing adjacent to said plug end thereof, said plug means including two plugs each of which is adapted to terminate one of the optical fibers of the cable for connecting the terminated optical fibers to other light paths disposed in apparatus to which said housing is connected; and

reciprocally movable means mounted on said housing for protecting said plug means prior to interconnecting said plug means with other light paths; and

a coupling which includes two end portions and a center portion, at least one of said end portions including a cavity adapted to receive the housing of a terminated optical fiber cable and said center portion including two tunnels which communicate with said cavity of said one end portion, said tunnels adapted to receive plugs which terminate optical fibers so that their end faces are adjacent to the other light paths.

19. The optical fiber connection system of claim 18, wherein said plug means includes an end portion which includes two spaced collars and a passageway therethrough and a plug which extends through and from said end portion and which includes a shoulder fixed to an end of said plug, and an associated compression spring which is disposed about said plug and which engages one of said spaced collars and said shoulder, each of said plug means adapted to be mounted in one of said mating portions of said housing, said housing including opposing lips which are received between said spaced collars to hold said plug means therein such that forces applied to each said plug cause the associated spring to be compressed and said plug to be moved through said passageway in said end portion of said plug means and into said housing.

20. The optical fiber connection system of claim 19, wherein said housing includes two flexible sidearms each being attached to said housing adjacent to said plug end of said housing and having a free end adjacent to said cable end, each of said sidearms including a latching nub which extends outwardly and which is adapted to be received in a window of said coupling into which said connector is adapted to be received to become operatively connected to other light paths.

21. The optical fiber connection system of claim 20, wherein said means for protecting said plug means includes bumper means which includes an end portion which extends parallel to an end face of the connector and two depending side portions each being received in a groove of a sidewall of one of the mating portions of said housing, said bumper means also including a post which extends inwardly into said housing from said end portion and a spring disposed between an end of said post and an abutment within said one portion of said housing, said end portion of said bumper means also including two spaced openings each being aligned with one of said plugs and spaced therefrom so that the end portion of each said plug is protected from impact and so that each plug may be moved through its associated opening to provide a connection with another light path.

22. The optical fiber connection system of claim 21, wherein said housing includes spring means disposed in said housing, said spring means in an unoperated condition engaging said bumper means to prevent retrograde movement of said bumper means and which in an operated condition is disengaged from said bumper means to allow said bumper means to be moved toward said cable end of said connector to expose said plugs, said spring means including portions supported in said base, and ramp portions extending through openings in said cover, said ramp portions adapted to be engaged by camming portions which extend into a cavity of said coupling into which the plug end portion of said connector is adapted to be received to cam said ramp portions inwardly and move tabs extending from legs, which connect said ramp portions with support portions adjacent to said base, toward said base to disengage said tabs from a collar which is disposed about an inner end of said post so that when said end portion of said bumper means engages said coupling, said bumper means is allowed to be moved toward said cable end of said housing upon further movement of said connector into the coupling cavity.

23. The optical fiber connection system of claim 18, wherein said reciprocally movable means includes a hood which is slidably mounted on said housing, said hood being adapted to receive an end portion of said coupling having a center portion into which said plugs are adapted to extend to operatively connect to other light paths at the other end of the coupling, said housing including two sidearms each being attached to said cable end of said housing and having a free end which includes a latching nub adjacent to said plug end, said hood being adapted to snap-lock into an extended position to protect said plugs and in a retracted position adapted to allow said latching nubs of said arms to become disposed in windows of said coupling.

24. The optical fiber connection system of claim 18, wherein said force transfer means includes

a bushing which is disposed in said housing and which includes a tapered passageway which is defined by a substantially smooth surface;

and

a truncated conically shaped wedging member which is received in said passageway of said bushing and which has an outer surface which is substantially smooth and conformable to said surface of said bushing, said bushing and said wedging member cooperating to receive an end of the cable in a small diameter portion of said passageway with the non-metallic strength members being disposed between said surface of said bushing and said outer surface of said wedging member to cause tensile loads applied to the cable to be transferred to the bushing to prevent damage to the optical fibers which are terminated by said plug means, said wedging member having a longitudinally extending bore through which optical fibers of the cable extend.

25. An optical fiber connection, which comprises:

first and second terminated optical fiber cables, each of which includes;

an optical fiber cable which includes two individually buffered optical fibers, a plurality of non-metallic strength members and a jacket which encloses the two optical fibers; and

a duplex optical fiber connector for terminating said cable, said connector comprising;

a housing which includes a base and a cover mated with said base and which includes a plug end and a cable input end;

force transfer means supported in said base and including conformable conically shaped surfaces between which are captured portions of said strength members with small diameter portions of each conically shaped surface being oriented toward said cable input end of said housing to cause the strength members upon initial engagement with said force transfer means to be in engagement with said small diameter portions, such that any angle between successive portions of length of the strength members in engagement with and adjacent to said surfaces is at least a predetermined value;

plug means disposed in said housing adjacent to said plug end thereof, said plug means including two plugs each of which terminates one of the optical fibers of the cable for connecting the terminated optical fibers to other light paths disposed in apparatus to which said housing is connected; and

reciprocally movable means mounted on said housing for protecting said plug means prior to interconnecting said plug means with the other light paths; and

a coupling which includes a housing having two end portions and a center portion, each of said end portions including a cavity in which is received a housing of one of the terminated optical fiber cables and said center portion including two tunnels which communicate the cavities of said end portions, said plugs which terminate the optical fibers being received in said tunnels so that their end faces are adjacent to the other light paths.

26. The optical fiber connection of claim 25, wherein said plug means includes an end portion which includes two spaced collars and a passageway therethrough and a plug which extends through and from said end portion and which includes a shoulder fixed to an end of said plug, and an associated compression spring which is disposed about said plug and which engages one of said spaced collars and said shoulder each of said plug means adapted to be mounted in one of said mating portions of said housing, said housing including opposing lips which are received between said spaced collars to hold said plug means therein such that forces applied to each said plug causes the associated spring to be compressed and said plug to be moved through said passageway in said end portion of said plug means and into said housing.

27. The optical fiber connection of claim 26, wherein said housing includes two flexible sidearms each being attached to said housing adjacent to said plug end of said housing and having a free end adjacent to said cable end, each of said sidearms including a latching nub which extends outwardly and which is received in a window of said coupling in which said connector is received and connected to another said connector.

28. The optical fiber connection of claim 27, wherein said means for protecting said plug means includes bumper means which includes an end portion which extends parallel to an end face of the connector and two depending side portions each being received in a groove of a sidewall of one of the mating portions of said housing, said bumper means also including a post which extends inwardly into said housing from said end portion and a spring disposed between an end of said post and an abutment within said one portion of said housing, said end portion of said bumper means also including two spaced openings each being aligned with one of said plugs and spaced therefrom so that the end portion of each said plug is protected from impact prior to making the connection and so that each plug may be moved through its associated opening to provide the connection with the other plug.

29. The optical fiber connection of claim 28, wherein said housing includes spring means disposed in said housing, said spring means in an unoperated condition engaging said bumper means to prevent retrograde movement of said bumper means and which in an operated condition is disengaged from said bumper means to allow said bumper means to be moved toward said cable end of said connector to expose said plugs, said spring means including portions supported in said base, and ramp portions extending through openings in said cover, said ramp portions adapted to be engaged by camming portions which extend into said cavity of said coupling into which the plug end portion of each said connector is received to cam said ramp portions inwardly and move tabs extending from legs, which connect said ramp portions with support portions adjacent to said base, toward said base to disengage said tabs from a collar which is disposed about an inner end of said post so that when said end portion of said bumper means engaged said coupling, said bumper means was allowed to be moved toward said cable end of said housing upon further movement of said connector into the coupling cavity.

30. The optical fiber connection of claim 25, wherein said protective means includes a hood which is slidably mounted on said housing, each said hood receiving an end portion of said coupling, said housing including two sidearms each being attached to said cable end of said housing and having a free end which includes a latching nub adjacent to said plug end, said hood being adapted to snap-lock into an extended position to protect said plugs and in a retracted position adapted to allow said latching nubs of said arms to become disposed in windows of said coupling into which two of said duplex connectors are assembled to connect associated optical fibers thereof.

31. The optical fiber connection of claim 25, wherein said force transfer means includes a bushing which is disposed in said housing and which includes a tapered passageway which is defined by a substantially smooth surface;

and

a truncated conically shaped wedging member which is received in said passageway of said bushing and which has an outer surface which is substantially smooth and conformable to said surface of said bushing, said bushing and said wedging member cooperating to hold and end of the cable in a small diameter portion of said passageway with the non-metallic strength members being disposed between said surface of said bushing and said outer surface of said wedging member, said wedging member having a longitudinally extending bore through which optical fibers of the cable extend.

32. The optical fiber connection of claim 31, wherein a line disposed on the surface of the wedging member and disposed in a plane that passes through a longitudinal axis of the wedging member makes an angle of about 1.5 degrees with the longitudinal axis of the wedging member.

33. A housing for a duplex optical fiber connector which is used to terminate two optical fibers of a cable, said housing including:

a base which comprises a cable entrance end and a plug end, said plug end being adapted to hold two plugs each of which terminates an optical fiber;

a cover which is adapted to be mated with said base;

force transfer means adapted to be disposed adjacent to said cable entrance end and through which the optical fibers extend for clamping non-metallic filamentary strength members of the cable to transfer tensile forces applied to the cable to the housing, said force transfer means including two conformable substantially smooth conically shaped surfaces which diverge in a direction from said cable entrance end of said housing toward said plug end such that any angle between successive portions of length of the strength members in engagement with and adjacent to said force transfer means is at least a predetermined value; and

protective means mounted for reciprocal movement with respect to said housing for protecting end portions of the plugs which protrude from said housing and which is caused to be retracted when the connector is connected to another to expose the plugs and allow them to be operatively connected to plugs of the other connector.

34. The housing of claim 33, wherein said protective means includes bumper means mounted for reciprocal movement with respect to said housing and being effective in a normal unoperated condition for protecting ends of the plugs and in an operated condition being retracted to allow ends of the plugs to be exposed and to engage ends of the plugs of another duplex connector.

35. The housing of claim 34, wherein said means for protecting the plugs means includes bumper means which includes an end portion which extends parallel to an end face of the connector and two depending side portions each being received in a groove of a sidewall of one of the mating portions of said housing, said bumper means also including a post which extends inwardly into said housing from said end portion and a spring disposed between an end of said post and an abutment within said one portion of said housing, said end portion of said bumper means also including two spaced openings each being aligned with one of the plugs and spaced therefrom so that the end portion of each plug is protected from impact and so that each plug may be moved through its associated opening to provide a connection with another plug.

36. The housing of claim 35, wherein said housing includes spring means disposed in said housing, said spring means in an unoperated condition engaging said bumper means to prevent retrograde movement of said bumper means and which in an operated condition is disengaged from said bumper means to allow said bumper means to be moved toward said cable end of said connector housing to expose the plugs, said spring means including portions supported in said base, and ramp portions extending through openings in said cover, said ramp portions adapted to be engaged by camming portions which extend into a cavity of a coupling into which a plug end portion of said connector housing is adapted to be received to cam said ramp portions inwardly and move tabs extending from legs, which connect said ramp portions with support portions adjacent to said base, toward said base to disengage said tabs from a collar which is disposed about an inner end of said post so that when said end portion of said bumper means engages the coupling, said bumper means is allowed to be moved toward said cable end of said housing upon further movement of said connector housing into the coupling cavity.