Abstract:
A turning tool ( 12 ) is inserted into the forward end of an outer housing ( 26 ) and its turning tips ( 18 ) are moved into tip receiving openings ( 24 ) at the base of the flange ( 26 ). The turning tool ( 12 ) is both pushed and rotated. The pushing moves the flange ( 46 ) back from the flange ( 24 ). The rotation rotates the inner housing ( 28 ), a ferrule ( 20 ) and an end portion of the cable, including an optical fiber (F) that is within the center line opening ( 78 ) in the ferrule ( 20 ). After the components have been rotated to provide a desired rotational position, the turning tool ( 12 ) is removed. Friction forces between the flange ( 46 ) and the flange ( 24 ) and between the cylindrical surface ( 48 ) and the cylindrical opening within the key ring ( 52 ) hold the components in the azimuthal position that was established.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to plug and receptacle connections for joining two fiber optic cables together for optical energy transmission from one cable to the other. More particularly, it relates to the provision of an optical fiber connector that includes a tubular ferrule for receiving a bared end portion of an optical fiber and to a construction of the connector that allows for an adjustment of the angular position of the optical fiber by rotating the ferrule and an end portion of a fiber optic cable that extends into the connector until a desired rotational alignment of the optical fiber is achieved, at which time the end portion of the fiber optics cable is fixed in position relative to the connector so that the rotational alignment of the optical fiber is maintained.  
         BACKGROUND OF THE INVENTION  
         [0002]    [0002]FIG. 1 of my allowed, pending U.S. application Ser. No. 09/649,283, filed Aug. 28, 2000, and entitled Plug And Receptacle Connection For Optical Fiber Cables With Alignment Feature, presents one example of a plug and receptacle connection for an optical fiber cable. application Ser. No. 09/649,283 sets forth a detailed description of the need for rotational alignment of the two optical fibers that are to be joined in order to obtain optimum results in the transmission of optical energy from one optical cable to the other optical cable. application Ser. No. 09/649,283 discusses prior art alignment systems that allow for a set number of azimuthal positions of the two cables. application Ser. No. 09/649,283 also discloses an alignment system in which an infinite number of azimuthal positions can be obtained. The present invention provides another way of adjustably positioning an end portion of a fiber optic cable and its optical fiber in an infinite number of azimuthal positions, for achieving optimum optical energy transmission from a first cable to a second cable.  
         BRIEF SUMMARY OF THE INVENTION  
         [0003]    The optical fiber connector of the present invention is basically characterized by a tubular outer housing and a tubular inner housing within the outer housing. The tubular inner housing comprises a forwardly opening front socket and a rearwardly opening rear socket that is in axial alignment with the front socket. A rear portion of a tubular ferrule is received within the front socket of the inner housing. The tubular ferrule has a center opening that is sized to receive a bared optical fiber. The tubular ferrule also has a front portion that extends forwardly from the rear portion of the ferrule and the front socket. A key ring is provided in the outer housing surrounding the front socket of the inner housing. The key ring is held against rotation relative to the outer housing and it includes a cylindrical inner surface. The front socket has a cylindrical outer surface that is sized to receive the cylindrical inner surface of the key ring. The cylindrical surfaces are sized such that the cylindrical inner surface of the key ring frictionally engages the cylindrical outer surface on the front socket. The inner housing and the ferrule are rotatable in position relative to the outer housing and the key ring when a rotational force is applied to them that is sufficient to overcome the friction between the cylindrical inner surface of the key ring and the cylindrical outer surface on the front socket.  
           [0004]    In preferred form, the key ring periphery includes alternating projections and cavities and the tubular outer housing includes complementary projections and cavities. The projections on the key ring are received in the cavities in the outer housing and the projections on the outer housing are received in the cavities in the key ring. The projections and cavities lock the key ring to the outer housing and prevent the key ring from rotating relative to the outer housing.  
           [0005]    Preferably, the tubular inner housing has a radially outwardly directed flange at its front end that is positioned to block forward movement of the key ring along the cylindrical outer surface of the front socket of the inner housing. Preferably also, the inner housing has a radially outwardly projecting girth ridge on it that is spaced axially rearwardly from the flange. The flange, the ridge and the cylindrical outer surface together define a girth groove surrounding the inner housing in which a base portion of the key ring is received. The ridge blocks rearward movement of the key ring along the cylindrical outer surface on the front socket of the inner housing.  
           [0006]    In preferred form, the tubular inner housing comprises a forwardly facing tool receiving portion that is radially outwardly of the front socket. The tool receiving portion is sized and shaped for receiving a complementary end portion of a tool that is used for rotating the tubular inner housing and the tubular ferrule relative to the outer housing. The tool receiving portion may comprise at least one forwardly directed tool-tip receiving opening in the forward end of the tubular inner housing. Preferably, however, the tool engaging portion comprises at least two forwardly directed tool-tip receiving openings in the forward end portion of the tubular housing. These openings are circumferentially spaced apart and are radially outwardly from the front socket. Preferably, there are two tool-tip receiving openings that are spaced substantially one hundred and eighty degrees (180°) apart.  
           [0007]    In the preferred embodiment, the outer housing includes a front section and a rear section and the two sections are telescopically connected together. The front section of the outer housing has a rearwardly directed socket and the rear section of the outer housing has a forwardly directed tubular pin that fits into the rearwardly directed socket in the front section of the outer housing. A lock structure is provided for connecting the front section of the outer housing to the rear section of the outer housing. This lock structure may comprise of at least one opening in a side wall of one of the housing sections and a complementary projection on the other housing section. By way of an example, the front section of the outer housing may include side wall openings on opposite sides of the front section. The rear section of the outer housing may include projections sized and positioned to snap fit into the openings in the front section when the rear section is telescopically moved into the front section.  
           [0008]    Preferably, the rear section of the outer housing includes a central opening in which a rear portion of the inner housing is received. The inner housing includes a radial shoulder, intermediate its ends. The rear section of the outer housing includes a radial shoulder intermediate its ends that is spaced rearwardly from the radial shoulder on the inner housing. A coil spring is positioned within the rear section of the outer housing in a position surrounding a middle portion of the inner housing. The spring has a first end that abuts against the radial shoulder on the inner housing and a second end that abuts against the radial shoulder on the rear section of the outer housing. This spring biases the inner housing, the lock ring and the ferrule axially forwardly within the outer housing.  
           [0009]    The front section of the outer housing may include a radially inwardly directed flange that is forwardly contiguous the radially outwardly directed flange at the front end of the inner housing. The coil spring biases the flange on the inner housing forwardly against the flange on the outer housing.  
           [0010]    Other objects, advantages and features of the invention will become apparent from the description of the best mode that is set forth below, form the drawings, from the claims and from the principals that are embodied in the specific structures that are illustrated and described. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0011]    Like reference numerals and letters are used to designate like parts throughout the several views of the drawing, and:  
         [0012]    [0012]FIG. 1 is a pictorial view of an embodiment of the connector of the present invention and a turning tool that is provided for rotating an inner portion of the connector;  
         [0013]    [0013]FIG. 2 is an enlarged scale axial sectional view of the connector shown by FIG. 1, and the tip portion of the tool, such view showing the tip portion of the tool spaced axially outwardly from a ferrule portion of the connector;  
         [0014]    [0014]FIG. 3 is a cross-sectional view taken substantially along line  3 - 3  of FIG. 2;  
         [0015]    [0015]FIG. 4 is a cross-sectional view taken substantially along line  4 - 4  of FIG. 2;  
         [0016]    [0016]FIG. 5 is a pictorial view of an inner housing component of the connector shown by FIGS.  1 - 4  and a ferrule at the forward end of the inner housing, both spaced in position relative to the key ring that is shown in FIG. 4 to be connected to the outer housing of the connector;  
         [0017]    [0017]FIG. 6 is an enlarged scale fragmentary sectional view taken through the ferrule and an optical fiber in the ferrule, such view showing a first azmuthal position of the optical fiber;  
         [0018]    [0018]FIG. 7 is a view like FIG. 6, but showing the optical fiber rotated into a second azmuthal position relative to the ferrule;  
         [0019]    [0019]FIG. 8 is an exploded pictorial view of the connector shown by FIGS.  1 - 5 ;  
         [0020]    [0020]FIG. 9 is an enlarged top plan view of the inner housing portion of the connector, including a fragmentary end portion of the turning tool, and showing the turning tips in axial alignment with the tip receiving recesses in the front end of the inner housing;  
         [0021]    [0021]FIG. 10 is an end view of the inner housing taken substantially along line  10 - 10  of FIG. 11;  
         [0022]    [0022]FIG. 11 is an axial sectional view of the inner housing taken substantially along line  11 - 11  of FIG. 10;  
         [0023]    [0023]FIG. 12 is an enlarged scale fragmentary view of the left end portion of FIG. 2, showing the turning tool in side elevation being moved into the end portion of the connector, in a position surrounding the ferrule, and showing the turning tips on the tool aligned with sockets for them provided in the outer end of the inner housing; and  
         [0024]    [0024]FIG. 13 is a view like FIG. 12, but showing the turning tool moved further into the connector, and showing the tips of the turning tool positioned in the socket, provided for them in the forward end portion of the inner housing. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]    [0025]FIG. 1 shows a connector  10  in a spaced relationship with a turning tool  12  that performs a function similar to that of a screwdriver. Tool  12  comprises a handle  14 , a cylindrical end portion  16  and a pair of tool tips or lugs  18  that axially project forwardly from the cylindrical portion  16 . The tips  18  are identical and are diametrically opposite each other. As will hereinafter be described in some detail, the cylindrical portion  16  of the tool  12  is sized to receive a ferrule  20 . The cylindrical portion  16  has a side wall that is positioned outwardly of and surrounds the ferrule  20 . As shown by FIG. 2, tool  12  is adapted to be moved into the cavity  22  until its tips  18  are within tool-tip receiving openings  24 .  
         [0026]    The connector  10  comprises an outer housing  26  and an inner housing  28 . Outer housing  26  is a front section  30  and a rear section  32 . Front section  30  has a forwardly directed cavity  22  or socket and a rearwardly directed socket  34 . The rear section  32  has a forwardly projecting tubular pin portion  36  that is telescopically received within the socket  34 . Side wall openings  38  are provided in the wall that forms the socket  34 . The rear section  32  includes barbs  40  which have front surfaces that slope rearwardly and rear surfaces that are substantially perpendicular to center line  42 . The sloping front surfaces allows the rear section  32  to be moved forwardly into the rear socket  34 . The sloping front surfaces push outwardly on the wall portions of the housing that are rearwardly of the openings  38 . When the barbs  40  become aligned with the openings  38 , they snap outwardly into the openings  38 . The rear surfaces of the barbs contact rear boundaries of the openings  38  and prevent easy withdrawal of the rear section  32  from the socket  34 .  
         [0027]    The inner housing  28  is best shown by FIGS.  9 - 11 . It is tubular in form and has a short and wide front socket  42  and a long and narrow rear socket  44 . As shown by FIG. 11, the front socket  42  opens forwardly and the rear socket  44  opens rearwardly. Inner housing  28  includes a radial flange  46  at its forward end. Flange  46  extends about the inner housing  28  except for in the regions of the tool-tip openings  24 . The outer surface  48  of the socket  42  is cylindrical. An annular ridge  50  projects radially outwardly form the outer surface at a location spaced rearwardly from the flange  46 . Ridge  50  has a cross-section like the barbs  40 . Its front surface is radial and its rear surface slopes rearwardly. The flange  46 , the cylindrical surface  48  and the ridge  40  together define a channel that extends about the socket  42 . This channel is herein sometimes referred to as a “girth” channel. It receives the base portion of a key ring  52  which is most clearly shown in FIGS. 5 and 8. Key ring  52  has a width that is substantially equal to the axially distance between flange  46  and ridge  50 . It includes a cylindrical inner surface  54  and radial projections  56  and radial recesses  58  that alternate around the circumference of the key ring  52 .  
         [0028]    As shown by FIG. 4, the front section  30  of the outer housing  26  includes a region composed of alternating projections  60  and recesses  62 . The projections  60  are sized to be received within the recesses  58  and the key ring  52 . The recesses  62  are sized to receive the projections  56  on the key ring  52 . Referring to FIGS. 5 and 8, the key ring  52  is slipped onto the inner housing  28  from the rear end of the inner housing  28 . It is moved forwardly until it reaches the ridge  50 . Then, it is forced forwardly over the ridge  50  and onto the cylindrical surface  48 . The sloping rear surface on the ridge  50  helps to cam the key ring  52  forwardly. When the key ring  52  is forwardly of the ridge  50 , it is trapped axially between the flange  46  and the ridge  50 . The radial front surface on the ridge  50  confronts a radial rear surface on the key ring  52  and blocks the key ring  52  from sliding rearwardly past the ridge  50 . The interlocking projections  56 , 60  and recesses  58 , 62  hold the key ring  52  against rotation relative to the front section  30  of the housing  26 .  
         [0029]    The diameter of the flange  46  is slightly smaller than the diameter defined by the inner surfaces of the projections  60 . This allows the flange  46  to be moved into the position shown in FIGS. 2, 12 and  13 , by an insertion of the inner housing and the key ring  52  through the space formed by the projections  60  and then moved forwardly until the flange  46  contacts the flange  70 .  
         [0030]    Referring to FIG. 2, the front section  30  of the outer housing  26  includes a radially inwardly extending flange  70 . Flange  70  includes a rear radial surface that is contacted by the front radial surface of the front end of flange  46  on the inner housing member  28 . Intermediate its ends, inner housing  28  includes a radial shoulder  72  that provides an abutment for the forward end of a coil compression spring  74 . The rear section  32  of the outer housing  26  includes a radial flange  76  which forms an abutment for the rear end of the coil spring  74 . The spring  74  is slightly compressed when it is in the position shown by FIG. 2. It exerts a force on the inner housing  28 , moving it forwardly relative to the rear section  32  of the outer housing  26 . Spring  74  biases the radial flange  46  in the contact with the radial flange  70 .  
         [0031]    U.S. Pat. No. 6,302,594, granted Oct. 16, 2001, to Hsin Lee, and assigned to Fiberon Technologies, Inc., discloses one way of connecting an end portion of an optical fiber cable to the connector, with a bared end portion of the optical fiber extending through a center line opening in the ferrule. Herein, a fiber receiving opening in ferrule  20  is designated  78  and the optical fiber is designated F. The manner of securing the end portion of the cable to the rear housing  28  is not a part of the present invention and so it will not be discussed any further. The important thing is that an end portion of the optical cable is connected to the inner housing  28  and a bared portion of the optical fiber F extends forwardly through the opening  78  in the ferrule  20 .  
         [0032]    The end portion of the cable is connected to the inner housing  28  while the rear section  32  of the outer housing  26  is moved rearwardly along the cable. Once the inner housing  28  is connected to the end portion of the cable, and the bared optical fiber F is within the opening  78  and ferrule  20 , the spring  74  is installed and the outer section  32  of the outer housing  36  is moved forwardly until the barbs  40  are within the openings  38 . During this movement, the spring  74  is compressed once the rear section  32  is connected to the front section  30 , by the barbs  40  being positioned within the openings  38 , the spring  74  biases the flange  40  on the front end of the inner housing  28  against the flange  24  that is inside of the forward section  30  of the outer housing  26 . Next, the ferrule  20 , the inner housing  28  and the end portion of the optical cable, including the bared portion of the optical fiber F that is within the opening  78  in the ferrule  20 , are rotated for the purpose of providing a desired rotation position of the optical fiber F. The cylindrical end portion  16  of the turning tool  12  is moved towards into the space  22  about the ferrule  20 . The tool  12  is moved forwardly until its tips or lugs  18  are within the opening  24  in the flange  46  that is at the forward end of the inner housing  28 . The turning tool  12  is moved inwardly and at the same time it is rotated. The inward movement will move the inner housing  28  rearwardly against the spring  74 . The rotational movement of the tool  12  will cause the lugs to function in the openings  24  much like the tip of a screwdriver in the slot of a screw. As the tool  12  is turned or rotated, it in turn rotates the inner housing  28  and the ferrule  20  that is carried by the inner housing  28 . It also rotates the optical fiber F about its axis. After a desired rotational position of the optical fiber F is achieved, the tool  12  is removed. The spring  74  once again forces the flange  46  forwardly against the flange  24 . Also, there is a frictional grip between the inner surface of key ring  52  and the cylindrical outer surface of the front end socket  42  in the inner housing  28 . The pressure of the flange  46  against the flange  24  and the friction between the cylindrical surface  48  and the cylindrical inner surface of the key ring  52  hold the alignment that was obtained by the rotation of the inner housing  28 , the ferrule  20  and the optical fiber F. As can be appreciated, this matter of locking the inner housing  28  to the outer housing  26  provides for adjustably affixing the optical fiber F in an infinite number of azmuthal positions within the connector.  
         [0033]    The illustrated embodiments are only examples of the present invention and, therefore, are non-limitive. It is to be understood that many changes in the particular structure, materials and features of the invention may be made without departing from the spirit and scope of the invention. Therefore, it is my intention that my patent rights not be limited by the particular embodiments illustrated and described herein, but rather are to be determined by the following claims, interpreted according to accepted doctrines of patent claim interpretation, including use of the doctrine of equivalents and reversal of parts.