Abstract:
An electrical connector having a connector housing with a first surface with a center portion, the first surface having a circular periphery. A set of contacts disposed around the center portion of the round connector housing and accessible through a set of openings in the first surface of the connector housing.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of use of connectors. More particularly, the present invention relates to a circular connector system for electronic devices. 
     BACKGROUND 
     Currently, devices such as computer systems and peripherals, consumer electronic devices, and other electronic devices are connected to each other through the use of cables. In some cases, multiple cables are used to connect these devices, which can tangle and disconnect. Often, when devices are stacked on top of each other, long cables are extraneous and cause more clutter than is necessary. 
     An exemplary system that exists for eliminating or reducing the use of cables uses a rack-type of structure with pre-existing slots, shelves or grooves to hold a fixed number of devices, and a set of connectors on a backplane used to connect to each device as they are inserted. Each device has one or more connectors on a back plate of the device that connect to a corresponding number of connectors in the set of connectors on the backplane of the rack. The rack contains one input/output connector on the back of the rack that is connected to all the connectors on the backplane. One drawback to the rack system is that when the number of devices to be interconnected exceeds the number of slots in the rack, the system is expandable only by adding another rack or modifying the existing rack. Also, as the connection between the device and the rack is often hidden from the user&#39;s view as it is being made, misaligned connections are not readily apparent. Connections can also be faulty where devices are not fully inserted, leaving connectors between the devices and the rack only partially mated. 
     Thus, a connector system that solves one or more of the above problems is desirable. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The system is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicated similar elements and in which: 
     FIG. 1 is an isometric view of a plug connector in one embodiment of the present invention. 
     FIG. 2 is an isometric view of a receptacle connector in one embodiment of the present invention. 
     FIG. 3 is an exploded isometric view of the plug connector of FIG.  1 . 
     FIG. 4 is an isometric view of a contact support from the plug connector. 
     FIG. 5 is an exploded isometric view of the receptacle connector of FIG.  2 . 
     FIG. 6 is a top-down view of the plug connector. 
     FIG. 7 is a top-down view of the receptacle connector. 
     FIG. 8 is a cross-sectional view of the plug connector in proximity to the receptacle connector. 
     FIG. 9 is a cross-sectional view of the plug connector mated with the receptacle connector. 
     FIG. 10 is a cross-sectional view of an alternate embodiment of the plug connector in proximity to an alternate embodiment of the receptacle connector. 
    
    
     DETAILED DESCRIPTION 
     The present invention is directed to a circular connector system. The circular connector system, in one embodiment, is used to provide electrical connection for transferring signals between two or more devices where the one device is stacked on top of another device. 
     FIG. 1 is an isometric view of a plug connector  100 , including a circular housing  102  configured to mate with a receptacle connector  200  as shown in FIG.  2 . Housing  102  contains an integrated keying/alignment element  106  and a set of openings  108  displaced around a center portion  104 . A set of contacts  110  is accessible through set of openings  108 . In another embodiment, set of contacts  110  includes additional contacts accessible through a second set of openings displaced on an outer perimeter  118 . In yet another embodiment, set of openings  108 , instead of being displaced around center portion  104 , is only displaced around outer perimeter  118 . 
     FIG. 3 is an exploded isometric view of plug connector  100  of FIG. 1, where a contact support  302  is exposed. Contact support  302  is further described below in FIG.  4 . Also visible in FIG. 3 is a set of circuit board contacts  308  on a circuit board  112 . Set of contacts  110  is connected to set of circuit board contacts  308 . Set of circuit board contacts  308  is connected to a plug  114  located on a second surface of circuit board  112  through a set of traces in circuit board  112  (not shown). Set of circuit board contacts  308  may also be connected to other components on circuit board  112 , such as integrated circuits (IC), resistors, capacitors, transistors, switches, and even other circuit boards, connected to additional circuit board contacts (not shown) using the traces in circuit board  112 . Circuit board  112  may be a single or multi-layer printed circuit board (PCB). Circuit board  112  may be a rigid or flexible circuit board. 
     As shown in FIG. 1, a ribbon cable  116  is connected to plug  114  to access the set of traces in circuit board  112 . Plug  114  is attached to a set of pins (not shown) on circuit board  112 . Through ribbon cable  116 , plug connector  100  can connect to another circuit board (not shown) or other components. In another embodiment, the set of traces in circuit board  112  may be accessed through a set of contact surfaces on top of circuit board  112 . 
     Housing  102  may be made of any single type of or composite material such that the material surrounding set of openings  108  is not conductive to electricity. In one embodiment, housing  102  is made of a plastic material, such as Acrylonitrile-Butadiene-Styrene (ABS). In another embodiment, housing  102  may be made out of a clear plastic material. In yet another embodiment, housing  102  may be made out of a combination of plastic and metal materials, where portions of housing  102  may use metal to allow housing  102  to act as a conductor (e.g., for signal or for grounding), or as shielding. Again, the material used surrounding set of openings  108  is preferably not electrically conductive. Similarly, contact support  302  may also be made of the same material as housing  102 . In contrast, set of contacts  110  may be constructed using any conductive material. In one embodiment, set of contacts  110  may be constructed using gold. In another embodiment, set of contacts  110  may be constructed using copper. The choice of materials for housing  102 , contact support  302 , and set of contacts  110  is dependant on the application for the connector system. 
     FIG. 4 is an isometric view of contact support  302 . Contact support  302  is used to support set of contacts  110  and contains a set of slots  402  used to receive set of contacts  110 . In one embodiment, contact support  302  includes an upper side section  404  that is shaped to conform to set of contacts  110  for support. Contact support  302  also includes a bottom side section  406  that may conform to support set of contacts  110 . In another embodiment, only the portion of upper side section  404  or bottom side section  406  that is useful for supporting set of contacts  110  is shaped to conform to set of contacts  110 . Set of contacts  110  may be molded onto contact support  302  before set of contacts  110  are attached to set of circuit board contacts  308  through a process such as a solder reflow process. 
     FIG. 2 is an isometric view of a receptacle connector  200 . Receptacle connector  200  includes a circular housing  202  that has a keying/alignment element  206  and a set of openings  208 . A set of contacts  210  protrudes from set of openings  208 . In another embodiment, set of openings  208  may include a set of openings located on an outer perimeter  218 . In this embodiment, set of contacts  210  includes a set of contacts that are accessible through the set of openings on outer perimeter  218 . In yet another embodiment, set of openings  208  are located on outer perimeter  218 . Set of contacts  210  is mounted to a circuit board  212  through a set of circuit board contacts  508  on circuit board  212  (not shown). Circuit board  212  is connected to a plug  214  that is on a ribbon cable  216 . 
     FIG. 5 is an exploded isometric view of receptacle connector  200 , where set of contacts  210  and set of circuit board contacts  508  are exposed. Set of circuit board contacts  508  is connected to a set of traces in circuit board  212  (not shown). Plug  214  is also connected to the set of traces. Similar to the set of traces in circuit board  112 , the set of traces in circuit board  212  allows the connection of circuit board contacts  508  to plug  214  and other components, such as ICs, resistors, capacitors, transistors, switches, and other circuit boards. In addition, circuit board  212  may be a single or multi-layered PCB as either a rigid or a flexible circuit board. 
     FIG. 6 is a top-down view of plug connector  100  where keying/alignment element  106  is further detailed. FIG. 7 is a top-down view of receptacle connector  200  where keying/alignment element  206  is also further detailed. Keying/alignment element  106  includes two different sized keying/alignment elements  602  and  604 . Similarly, keying/alignment element  206  also includes two different sized keying/alignment elements  702  and  704 . The size and shapes of keying/alignment elements of plug connector  100  are matched to keying/alignment elements of receptacle connector  200 . Specifically, the sizes and shapes of keying/alignment elements  602  and  604  are matched to keying/alignment elements  702  and  704 , respectively, to reduce the chance of a misalignment in connecting the connectors. 
     In other embodiments, a different number of keying/alignment elements may be used. This may be as few as a single keying/alignment element. In addition, the keying/alignment elements may be of different shapes and sizes to further reduce the chance of misalignment in connections. The keying/alignment elements may also be located at the center of the connectors. For example, a keying/alignment element may be located on center portion  104  on plug connector  100 , with a corresponding keying/alignment element located on a center portion of receptacle connector  200 . 
     FIG. 8 is a cross-sectional view of plug connector  100  in proximity to receptacle connector  200 . Circular housing  202  of receptacle connector  200  contains set of openings  208  through which set of contacts  210  is accessible. In addition, circular housing  102  of plug connector  100  also contains set of openings  108  through which set of contacts  110  is accessible. Set of contacts  110  are supported by contact support  302  such that set of contacts  110  do not substantially move when set of contacts  210  comes into connection with set of contacts  110 . Instead, set of contacts  210  is able to deflect. In another embodiment, set of contacts  110  is unsupported and is also able to deflect. In yet another embodiment, set of contacts  210  is supported and does not deflect. Set of contacts  210  has an “S” shape to deflect and to absorb flex. 
     FIG. 9 is a cross-sectional view of plug connector  100  mated with receptacle connector  200 . Set of connectors  210  is in contact with set of connector  110 . As can be seen in FIG. 9, set of contacts  210  is deflected as set of contacts  110  is supported by contact support  302 . 
     In implementations where the connector system is used to connect devices in a vertical manner (i.e., where devices are stacked vertically), plug connector  100  is typically used as a top connector and receptacle connector  200  is typically used as a bottom connector. For example, where the connectors are used to couple a top device to a bottom device, plug connector  100  is affixed on the top of the bottom device, while receptacle connector  200  is affixed at the bottom of the top device. In this case, the devices are coupled simply by placing the top device on the bottom device. As discussed above, alignment between the connectors is through keying/alignment elements on the connectors. 
     In FIG. 10, an alternate embodiment is illustrated where set of contacts  110  is shaped to mechanically engage and hold set of contacts  210  in addition to providing electrical connections. Set of contacts  110  contains a curved portion mirrored to an oppositely curved portion on set of contacts  210 , where set of contacts  110  has an indented portion  110   a  and set of contacts  210  has a protruded portion  210   a  matched to substantially fit indented portion  110   a . With set of contacts  210  displaced radially around set of contacts  110  during the connection of plug connector  100  to receptacle connector  200 , there is enough force in the deflection of set of contacts  210  to couple the two sets of contacts. In addition, the engagement of indented portion  110   a  in set of contacts  110  to the protruding portion  210   a  in set of contacts  210  keeps the connectors coupled. 
     In another embodiment, the contacts in set of contacts  110  have a protruding portion instead of an indented portion. The protruding portion may or may not be supported by contact support  302 . Also, depending on the configuration of the connectors, not all contacts need to have an indented or protruding portion. This allows the connectors to be snapped together during connection with less force. Thus, for example, every third contact may have a protruding or indented portion. In addition, contacts in both set of contacts  110  and set of contacts  210  may contain multiple protruding or indented portions. 
     In another embodiment, a separate latching mechanism (not shown) is used to mechanically hold the two sets of contacts. This latching mechanism may be integrated with the connectors or located separately. For example, two hooks (not shown) may be used on plug connector  100  that are matched to two loops (not shown) on receptacle connector  200 , one on each side, to supplement or provide mechanical fastening when the connectors are engaged. Also, a set of detents, matched to a set of protrusions, may be used on the connectors either along with or in place of the latching mechanism created by the protruding and indented portions in the contacts. 
     In yet another embodiment, plug connector  100  includes a protective sheath (not shown) that retracts when plug connector  100  connects to receptacle connector  200 . The sheath protects the connectors on plug connector  100  and may have a mechanical or spring loaded catch for releasing the sheath. Receptacle connector  200  may also have a protective sheath such that either plug connector  100 , receptacle connector  200 , or both may have protection for the contacts. 
     In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.