Abstract:
A one-piece LC type optical fiber adapter is provided. The LC type adapter of the present invention has fewer parts than a conventional one. Therefore, it is simpler and easier to assemble the LC type adapter of the present invention. In addition, the main body of the LC type adapter is unitary thereby avoiding the prior art problem that the stresses cause the two halves of the adapter to separate from each other after time.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part application of U.S. Ser. No. 12/199,581 filed Aug. 27, 2008, the full disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fiber adapter, and more particularly, to a one-piece LC type optical fiber adapter. 
         [0004]    2. Description of the Related Art 
         [0005]    Fiber optics has revolutionized communication through out the world. With the increased used of fiber optics it has become increasingly important to be able to connect and disconnect fiber optic cables from various sources. Two fiber optic cables can be optically coupled so that they are in communication with each other by using connectors and an adapter, thereby putting each fiber optic cable in communication with the other. The connectors are placed on the end of each cable and then plugged into the adapter. The adapter has two openings each one designed to receive a connector. 
         [0006]    The conventional LC type adapter consists of two halves, each halve being identical. Each half consists generally of a rectangular cylinder having a flange at one end. Inside each half would be placed half of an inner housing. The inner housing is generally a round cylinder with a flange at one end. Each adapter half has a ridge located just inside from its flange so that the inner housing could be placed in the adapter through the opening proximate to the flange on the adapter half. Once the inner housing is inserted into each adapter half, the two halves are connected by ultrasonically welding the two flanges of the adapter halves together. 
         [0007]    However, the above design presents serious problems. The cables are naturally flexed in use when the adapter remains fixed. The related stress of this situation can cause the two halves of the adapter to separate from each other after time. In the prior art, this problem can be solved by constructing the adapter halves from metal which gives the adapter enough strength to withstand these stresses. However, this too presented a problem as metal is much more expensive to purchase and mold than the plastic one. 
         [0008]    Accordingly, there exists a need to provide a LC type optical fiber adapter to solve the aforesaid problems. 
       SUMMARY OF THE INVENTION  
       [0009]    It is an object of the present invention to provide a one-piece LC type optical fiber adapter that has fewer parts than a conventional one. It is simpler and easier to assemble the LC type adapter of the present invention. In addition, the main body of the LC type adapter is unitary thereby avoiding the prior art problem that the stresses cause the two halves of the adapter to separate from each other after time. 
         [0010]    In order to achieve the above object, the one-piece LC type optical fiber adapter of the present invention includes a unitary main body, an inner housing and a cover. The unitary main body has an axial cavity defined by a first side-wall, a second side-wall, a third side-wall and a fourth side-wall. The first side-wall faces the third side-wall and connects with the second and fourth side-walls. The main body has two opposing axial openings. At least one compartment wall is positioned in the axial cavity. The compartment wall is parallel to the second and fourth side-walls and connects with the first and third side-walls and divides the axial cavity into a plurality of parts. The first side-wall has an access opening thereon. An indentation is formed on the top of the compartment wall. A pair of parallel ridges is positioned on the inner surface of the third side-wall and divides the compartment wall into two halves. The two ridges define a first groove. The second side-wall has a second groove on the inner surface thereof and the fourth side-wall has a third groove on the inner surface thereof. The first groove is in communication with the second and third grooves. A plurality of protrusions is located near the two axial openings on the inner surfaces of the second and fourth side-walls and on opposite sides of the compartment wall, respectively. The inner housing has a flange and a plurality of hollow cylinders through the flange. The cover is configured to cover the access opening on the first side-wall, wherein the cover has a protruding portion formed thereon and a protrusion formed on the protruding portion. The protruding portion is positioned corresponding to the indentation on the top of the compartment wall. The axial cavity of the main body is adapted to receive the inner housing and the first, second and third grooves are adapted to receive the flange. The inner housing can be slid into place within the main body through the opening on the first side-wall. The indentation on the top of the compartment wall is configured to receive the protruding portion and molten protrusion on the cover when the protrusion on the cover is melted and the cover is brought to cover the access opening. 
         [0011]    The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]      FIG. 1  is an elevated perspective view of a conventional LC type fiber adapter. 
           [0013]      FIG. 2  is an elevated perspective view of the main body of the fiber adapter according to the present invention. 
           [0014]      FIG. 3  is an exploded view of the fiber adapter of the present invention. 
           [0015]      FIG. 4  is an elevated perspective view of the fiber adapter of the present invention, wherein the inner housing has been placed in the main body. 
           [0016]      FIG. 5  is an elevated perspective view of the cover of the fiber adapter according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]    Referring to  FIG. 1 , a conventional LC type fiber connector  100  has a generally rectangular shape with a square cross section. The outer surface of the connector  100  includes a spring latch  120 . The spring latch  120  is molded into the outer housing of the connector and includes a living hinge  125  which allows tab  126  to be moved up and down in a direction perpendicular to the central axis  150 - 150  of the connector  100 . In addition, a ferrule  140  protrudes from the opening  111  of a two-piece assembly comprising housing  110  and cover  130  which have been ultrasonically bonded together. A spring (not shown in the figure) is located inside the two-piece assembly to allow the ferrule  140  to move back and forth through the opening  111 . The spring latch  120  includes a pair of shoulders  121  that are positioned on opposite sides of the tab  126 . 
         [0018]    Referring to  FIGS. 2 to 5 , the duplex fiber adapter  200  of the present invention includes a unitary molded main body  205  and a cover  300 . In the preferred embodiment, the main body  205  has an axial cavity defined by top side-wall  210 , bottom side-wall  211 , right side-wall  212  and left side-wall  213 . The axial cavity is divided into two halves by a compartment wall  214  that is parallel to the right side-wall  212  and left side-wall  213  and connects with the top side-wall  210  and bottom side-wall  211 . The half of the axial cavity defined by the top side-wall  210 , bottom side-wall  211 , compartment wall  214  and right side-wall  212  is named as the right axial cavity and the other half of the axial cavity defined by the top side-wall  210 , bottom side-wall  211 , compartment wall  214  and left side-wall  213  is named as the left axial cavity. The right axial cavity has opposing first right opening  207   a  and second right opening  208   a  and the left axial cavity has opposing first left opening  207   b  and second left opening  208   b.  In addition, an indentation  219  is formed on the top of the compartment wall  214 . 
         [0019]    Located on the exterior of the main body  205  is a pair of tabs  201  and  202 . One tab  202  is located on the right side-wall  212  and the other tab  201  is located on the left side wall  213 . The tabs  201  and  202  are operative in supporting the adapter  100  on a surface. The inner cavity of the main body  205  contains a pair of parallel ridges  235  and  236  located on the inner surface of the bottom side-wall  211 . The ridges  235  and  236  are perpendicular to the axial cavity of the main body  205  and divide the compartment wall  214  into two halves. 
         [0020]    The ridges  235  and  236  define a groove  238  which is perpendicular to the axial cavity of the main body  205 . The groove  238  is half way between the first openings  207   a,    207   b  and second openings  208   a,    208   b  of the main body  205 . The width of the groove  238  is equal to the thickness of combined flanges  450  of the inner housing halves  410  and  420 . The right side-wall  212  and left side-wall  213  each has a groove  239  that is collinear with the groove  238 . Two indentations  237  are formed on the joint of the tab  202  with the right side-wall  212  and on the joint of the tab  201  with the left side-wall  213 , respectively. The indentations  237  are in communication with and collinear with the grooves  239 . 
         [0021]    Located near the right opening  207   a  on the joint of the right side-wall  212  with the bottom side-wall  211  and on the joint of the compartment wall  214  with the bottom side-wall  211  are protrusions  262 . The protrusions  262  are also located near the left opening  207   b  on the joint of the left side-wall  213  with the bottom side-wall  211  and on the joint of the compartment wall  214  with the bottom side-wall  211 . Similarly, these protrusions  262  are also located near the openings  208   a,    208   b  on the joints of the bottom side-wall  211  with the right side-wall  212 , compartment wall  214  and left side-wall  213 , respectively. 
         [0022]    An access opening  250  is located on the top side-wall  210 . The access opening  250  allows inner housing halves  410  and  420  to be inserted into the axial cavity of the main body  205  and also allows the main body  205  to be constructed by injection molding. 
         [0023]    The inner housing halves  410  and  420  are identical. Each of the inner housing halves  410  and  420  is constructed of plastic by an injection molding process. Each half includes two hollow cylinders  440  and a rectangular flange  450  located at one end of the cylinder  440 . Two halves  410  and  420  are connected at their respective flanges  450  respectively so as to define two common cylinders. Two flanges  450  define a thickness which is equal to the widths of the groove  238  and  239 . The inner housing halves  410 ,  420  are placed in the main body  205  by aligning the flange  450  of the inner housing half  410  with collinear grooves  238  and  239  and sliding it into place within the main body  205 . The other inner housing half  420  is inserted into the main body  205  in the same fashion. 
         [0024]    The cylinders  440  of the inner housing halves  410  and  420  are coaxial in the main body  205  and define two common cylinders. Located in each of the common cylinders is a hollow sleeve  500  with a generally cylindrical shape. The cover  300  has a bottom surface  320  and a rectangular protruding portion  330  positioned on the bottom surface  320 , wherein the protruding portion  330  is arranged corresponding to and can be placed with the indentation  219  on the compartment wall  214 . A smaller protrusion  332  is formed on the protruding portion  330 . The protrusion  332  has a rectangular bottom surface and a triangular cross-section. In addition, the cover  300  further includes a pair of ribs  310 , which are positioned corresponding to the indentations  237  on the tabs  201 ,  202 , respectively (See  FIG. 5 ). 
         [0025]    When desiring to assemble the fiber adapter  200 , the inner housing halves  410  and  420  are inserted into the axial cavity of the main body  205  through the access opening  250 . Afterward, the protrusion  332  on the cover  300  is ultrasonically melted and the cover  300  is brought to cover the access opening  250 . At this moment the protruding portion  330  will be placed within the indentation  219  on the compartment wall  214  and the molten protrusion  332  will bond to the compartment wall  214  so that the cover  300  can be tightly attached to the main body  205 . Since the ribs  310  of the cover  300  are arranged corresponding to the indentations  237  on the tabs  201  and  202 , the ribs  310  will be placed within the indentations  237  when the cover  300  is brought to cover the access opening  250 . 
         [0026]    In operation the connector  100  is inserted into the main body  205  from, for example, the first right opening  207   a.  The shoulders  121  positioned on the opposite sides of the tab  126  of the spring latch  120  are pushed by the protrusions  262  to cause the spring latch  120  to be deflected downward during the insertion into the main body  205 . The ferrule  140  of the connector  100  is inserted into one end of the hollow sleeve  500  in the right axial cavity. When the shoulders  121  pass over the protrusions  262 , the spring latch  120  is then returned to its original position by its own restorative force to have the shoulders  121  moved upward to position behind the protrusions  262 . The protrusions  262  can stop the backward movement of the shoulders  121  to prevent the connector  100  from being pulled out from the adapter  200 . Another connector  100  can be inserted into the main body  205  from the second right opening  208   a  in the same manner to have its ferrule  140  to be inserted into the other end of the sleeve  500  in the right axial cavity. The end face of the ferrule  140  will be brought into contact with that of the previous ferrule  140 . Similarly, two connectors  100  can be inserted into the main body  205  from the first left opening  207   b  and the second left opening  208   b  respectively to optically couple with each other. 
         [0027]    In addition to duplex fiber adapter, the fiber adapter of the present invention can also be designed to couple four pairs of connectors (not shown in the figure). More specifically, the axial cavity in the main body of the adapter is divided into four parts by three parallel compartment walls. Four connectors can be inserted into the front ends of the four parts of the axial cavity respectively in the above-described manner. Similarly, another four connectors can be inserted into the rear ends of the four parts of the axial cavity to couple with the opposite connectors, respectively. Since the structure of this adapter is substantially identical to that of the adapter  200 , any further illustrations of such adapter are omitted herein. 
         [0028]    Since the main body of the fiber adapter according to the present invention is unitary, the prior art problem that the stresses cause the two halves of the adapter to separate from each other after time can be avoided. 
         [0029]    Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.