Patent Publication Number: US-7591680-B2

Title: Conductive cage

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a conductive cage to avoid electromagnetic interference (EMI). 
   2. Description of the Prior Art 
   A small form-factor pluggable transceiver (SFP transceiver) provides a link between an electronic transmission line and an optical transmission line as a bi-direction optical-electronic converter. The SFP transceiver is mounted on a printed circuit board of a host system device via a high-speed connector. Then SFP transceiver and the connector are received in a conductive cage to avoid EMI. 
   U.S. Patent publication No. 2007/0117458 published on May 24, 2007 discloses an EMI-minimized transceiver received in a transceiver cage. The transceiver cage has a cage body and an outer shield. The cage body is of rectangular configuration and has a receiving space for receiving the EMI-minimized transceiver. The outer shield is rectangular and includes four side portions, an open corner defined between two adjacent side portions and a plurality of fingers extending from the side portions for contacting with a chassis. The outer shield is held on the cage body by spot welding the side portions to the cage body. 
   During assembly, the side portion is so small that it&#39;s difficult to spot weld the outer shield to the cage body. The reliability of the cage cannot be ensured. 
   Hence, an improved conductive cage is needed to solve the above problem. 
   BRIEF SUMMARY OF THE INVENTION 
   Object of the present invention is to provide a conductive cage having a unitary, rectangular-shaped collar easily mounted onto a cage body. 
   The present invention provides a conductive cage mounted on a printed circuit board for receiving a SFP transceiver comprising a cage body having a plurality of pins extending downwardly, and a unitary rectangular-shaped collar mounted onto the cage body. The unitary rectangular-shaped collar has a top plate, a pair of opposite side plates and a bottom plate. The bottom plate has a first bottom plate half including a first engaging portion and a second bottom plate half having a corresponding second engaging portion coupling with the first engaging portion for connecting the first bottom plate half to the second bottom plate half. 
   Advantages of the present invention are to provide a unitary, rectangular-shaped collar punched by a metal strip and having a bottom plate including a first bottom plate half and a second bottom plate half connecting to the first bottom plate half firmly. The rectangular-shaped collar is mounted to the cage body by an interference between the unitary, rectangular-shaped collar and the cage body to ease the assembly of the conductive cage. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiments when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an assembled perspective view of a conductive cage and a chassis on which the conductive cage will be mounted; 
       FIG. 2  is a view similar to  FIG. 1  while taken from another aspect; 
       FIG. 3  is an exploded view of a conductive cage as shown in  FIG. 1 ; 
       FIG. 4  is a bottom view of a cage body as shown in  FIG. 3 ; and 
       FIG. 5  is an assembled perspective view of the conductive cage mounted into the chassis. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made to the drawing figures to describe the present invention in detail. Referring to  FIGS. 1-5 , a conductive cage  100  mounted on a printed circuit board (not shown) for receiving an SFP transceiver (not shown) comprises a cage body  10  and a unitary, rectangular-shaped collar  20  mounted to the cage body  10 . 
   The cage body  10  has a top wall  11 , a bottom wall  12  in parallel with the top wall  11 , a pair of side walls  13 , a rear wall  14  and a receiving opening  15  defined therebetween for receiving the SFP transceiver. The bottom wall  12  has a plurality of pins  122  extending downwardly therefrom for connecting with the printed circuit board, a recess  121  defined thereon and communicated with the receiving opening  15  and a spring plate  123  extending upwardly from the bottom wall  12 . 
   The unitary, rectangular-shaped collar  20  is punched by a metal strip and mounted onto the cage body  10 . The unitary, rectangular-shaped collar  20  has a top plate  21 , a pair of opposite side plates  23  and a bottom plate  22 . The bottom plate  22  comprises a first bottom plate half  221  having a first engaging portion  24  and a second bottom plate half  222  having a corresponding second engaging portion  25  coupling with the first engaging portion  24  for connecting the first bottom plate half  221  to the second bottom plate half  222 . The first engaging portion  24  is formed with a pair of first protrusions  241  and a first receiving recess (not labeled) defined between the pair of first protrusions  241 . The second engaging portion  25  is formed with a second protrusion  251  received in said first receiving recess. In another embodiment, the first engaging portion  24  is welded to the second engaging portion  25 . The bottom plate  22  further has a cutout  220  in communicating with the receiving opening  15  for coupling with the spring plate  123 . 
   The top plate  21  and the pair of side plates  23  of the unitary, rectangular-shaped collar  20  respectively has a plurality of contact fingers  26 , a base portion  28  and an opening  29  defined thereon. The contact fingers  26  rearwardly extend into the opening  29  and electrically contacting with a chassis  200  in which a conductive cage  20  is received. 
   During assembly, firstly, the first engaging portion  24  and the second engaging portion  25  are interconnected with each other by the interference between the second protrusion  251  and the two first protrusions  241 . Secondly, the unitary, rectangular-shaped collar  20  is mounted to the cage body  10  firmly. Finally, the conductive cage  100  mounted into a passage  201  defined on the chassis  200 . 
   It is to be understood, however, that even though numerous, characteristics and advantages of the present invention have been set fourth in the foregoing description, together with details of the structure and function of the invention, the disclosed is illustrative only, and changes may be made in detail, especially in matters of number, 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.