Abstract:
A cable assembly comprises a shell ( 1 ) comprising at least one post ( 127 ), a ferrite core ( 3 ) having two end face ( 33 ) and a main portion ( 32 ) and defining a perforation ( 31 ) and a cable ( 2 ) comprising a plurality of wires rounding the ferrite core by leading the cable to extend through the perforation at least once, and the cable forming at least one bending portion ( 21 ) adjacent to the one end face of the ferrite core, the post ( 127 ) of the shell disposing between the bending portion and the ferrite core.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a cable assembly, and particularly to a cable assembly having a ferrite core. 
   2. Description of Prior Arts 
   Usually, the signals between two electronic systems are transmitted by a cable, and the cable includes a plurality of wires. As two electronic systems need to transmit more and more signals, the number of the wires becomes more and more. Accordingly, the cable has to add a mechanism to resist the influence to the signals from transient electric current. A ferrite core is put on the cable to filtrate wave to resolve the above mentioned problem. The ferrite core defines a hole for the cable to extend through, and would perform more efficiently if the cable loops around the ferrite core more than one turn. The cable forms at least one bending portion adjacent to the end face of the ferrite core. Accordingly, the relative positions of the wires of the cable at the bending portion are changed. The change of the positions of the wires of the cable makes the impedance of the bending portion of the cable change. And the signals transmitted by the cable is changed suddenly because of the different impedance between the bending portion and the other portion of the cable. 
   Obviously, a new cable assembly is needed to resolve above mentioned problem. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a cable assembly with a filter that can prevent the signals from changing suddenly. 
   To achieve the above object, a cable assembly comprising a shell comprising at least one post, a ferrite core having a main portion, two end faces, and a perforation; and a cable comprising a plurality of wires, the cable extending through the perforation at least once to form at least one bending portion adjacent to one end face of the ferrite core; the post of the shell disposed between the bending portion and the ferrite core. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is an assembled, perspective view of a cable assembly in accordance with the present invention; 
       FIG. 2  is an exploded view of the cable assembly shown in  FIG. 1 ; 
       FIG. 3  is a view similar to  FIG. 2 , but taken from a different aspect; 
       FIG. 4  is another exploded view of the cable assembly shown in  FIG. 1 ; 
       FIG. 5  is an assembled, perspective view of a second embodiment of the cable assembly; 
       FIG. 6  is an exploded view of the cable assembly shown in  FIG. 5 ; and 
       FIG. 7  is a cross-sectional view of  FIG. 5  taken along line  7 - 7 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1-3 , the present invention relates to a cable assembly  100  with a filter. The cable assembly  100  includes a shell  1 , a cable  2  and a ferrite core  3 . 
   As shown in  FIGS. 2 and 3 , the shell  1  has an elliptical or oval cross-section, and comprises a top shell  11  and a bottom shell  12 . Both the top shell  11  and the bottom shell  12  are configured of semi-ellipse column. The bottom shell  12  forms a first inside wall  121 . There are two pairs of first rib boards  122  formed on the first inside wall  121 , and each pair of the first rib boards  122  are located face to face with each other. There are two blocks  123  and two posts  127  extending upwardly from the first inside wall  121  of the bottom shell  12 . The two blocks  123  and the two posts  127  are, respectively, face to face with each other. The two posts  127  are configured of semi-column, and comprises a semicircle cambered surface  1270  and a planar surface  1271 . The planar surfaces  1271  of the posts are face to face. There are a pair of first retaining portions  126  formed on the opposite sides of the bottom shell  12  in a longitudinal direction, and each first retaining portion  126  defines a first receiving passage  1260 . A pair of first locking arms  124  and a pair of first locking portions  125  are formed on the first inside wall  121  of the bottom shell  12  in a front-to-back direction, perpendicular to the said longitudinal direction. The top shell  11  comprises a second inside wall  111 , and two pairs of second rib boards  112  formed on the second inside wall correspond to the first rib boards  122  of the bottom shell  12 . There are a pair of second locking arms  114  and a pair of second locking portions  115  disposed on the second inside wall  111 . The first locking arms  124  lock with corresponding second locking portions  115  and the first locking portions  125  lock with corresponding second locking arms  114 . Thereby the top shell  11  is assembled to the bottom shell  12 . The top shell  11  has a pair of second retaining portions  116  on the opposite sides in the longitudinal direction. Each second retaining portion  116  defines a second receiving passage  1160 . 
   The cable  2  has a plurality of wires (not shown) for transmitting the signals between two electrical systems. And the cable  2  can be bended. 
   The ferrite core  3  is configured of column, and can eliminate the wave from the cable  2 . The ferrite core  3  comprises a main portion  32 , and a perforation in the longitudinal direction, and forms two end faces  33 , each end face  33  is configured of ring. 
   As shown in  FIG. 4 , the cable  2  loops around the main portion  31  of the ferrite core  3  by extending through the perforation  31  twice. And the cable  2  forms two bending portions  21  adjacent to the two end faces  33  of the ferrite core  3 . The ferrite core  3  can eliminate wave from the cable  2  by leading the cable  2  to extend through the perforation  31  and the ferrite core  3  can achieve a better effect by leading the cable  2  to extend through the perforation  31  twice or more. The ferrite core  3  with the cable  2  is assembled to the bottom shell  12 , the main portion  32  of the ferrite core  3  engages with the first rib boards  122  of the bottom shell  12 . Each first rib board  122  forms cambered surfaces to meet the outside surface of the main portion  32 . The two end faces  33  of the ferrite core  3  are sandwiched by the pair of blocks  123 . The post  127  is located between the bending portions  21  of the cable  2  and the end faces  33  of the ferrite core  3 . And each end face  33  of the ferrite core  3  bears against each planar surface  1271  of the post  127  respectively. The bending portions  21  of the cable  2  surround the semicircle cambered surfaces  1270  of the posts  127 . The thickness of the end faces  33  have the same dimension with the width of the planar surfaces  1271 . The cable  2  extending outside the perforation  31  can loop around the semicircle cambered surfaces  1270  of the posts  127  smoothly, and the bending portions  21  of the cable  2  can release stress concentration to retain the positions of the wires of the cable  2 . And the cable  2  has the same impedance at either the bending portion  21  or the other portion of the cable, the signals transmitting by the cable  2  can avoid changing suddenly. At last, the top shell  11  mates with the bottom shell  12 , and the second rib boards  112  of the top shell  11  press on the main portion  32  of the ferrite core  3 . Now the ferrite core  3  is fixed between the top shell  11  and the bottom shell  12  stably. The pair of first locking arms  124  lock with corresponding second locking portions  115  and the first locking portions  125  lock with corresponding second locking arms  114  to secure the bottom shell  11  and the top shell  12  together. The cable  2  extends out of both opposite sides (not labeled) of the shell  1 , and through the first receiving passages  1260  and the second receiving passages  1160 . After assembled, the cable assembly  100  can prevent the signals transmitting by the cable  2  from being influenced by changing suddenly. 
   Referring to  FIG. 5  to  FIG. 7 , the second embodiment of the cable assembly  100 ′ comprises a shell  1 ′, a cable  2 ′ and a ferrite core  3 ′. The difference between the first embodiment and the second embodiment is that the shell  1 ′ is over-molded on the cable  2 ′, and is not separated into a top shell and a bottom shell. 
   In this embodiment, the cable  2 ′ also loops around the main portion of the ferrite core  3 ′ by extending through the perforation  31 ′ twice. And the cable  2 ′ has two bending portions  21 ′. The shell  1 ′ is over-molded on the ferrite core  3 ′ with the cable  2 ′, and there is also a semi-column post  11 ′ disposed between the bending portion  21 ′ and the end face  33 ′ of the ferrite core  3 ′. The pair of posts  11 ′ act the same function as the pair of posts  127  referred to in the first embodiment. 
   So the cable assembly  100 ′ also can prevent the signals transmitting by the cable  2 ′ from influencing and changing suddenly. 
   It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.