Socket apparatus for a plug-in module

[0002] The present invention relates to apparatus for supporting modular electronic subsystems on electrical and electronic devices, and more particularly to a socket apparatus for receiving and supporting modular devices that are inserted into a host device, such as a printer or other peripheral device.

[0003] It has been a common practice in the manufacture of electronic components to provide additional functional capability in the form of modular electronic subsystems that can be easily coupled to larger electronic devices. One common example involved the use of font cartridges on laser and other printers in home and office environments. Such font cartridges were merely plugged into the printer and provided additional fonts for the user. Other examples included transceiver slots on network switches and in internal print servers and modules for multi-function peripheral devices, which could scan, fax, print and copy. The use of modular subsystems or components to vary the functionality of such peripheral devices was a convenient, flexible and inexpensive alternative to the replacement of such devices or the need to manufacture many different models of such devices to satisfy differing functional needs.

[0004] The disadvantages of such previous solutions included the necessity of using additional parts to provide mechanical support and retention of the auxiliary module. They also required the maintenance of tight tolerances between the host electrical connection and the module support. Some of the solutions also lacked a low impedance ground path, which can be important for reliability of operation. Moreover, some solutions utilized plastic resin which affected the amount of space required to provide sufficient mechanical strength.

[0005] The present invention relates to a socket apparatus for supporting modular devices that are inserted into the host device. The apparatus is a robust, low cost solution for supporting a module that is insertable into a host device and providing a low impedance RFI ground path for the module. The apparatus also supports and protects the host electrical connector, minimizes the number of host parts and tolerance back up and provides design flexibility to suppliers who provide modules for use in a host device.

[0006] The present invention is preferably mounted on a printed circuit board having a connector mounted thereto adapted to receive a connector in the module that is inserted into the socket apparatus. The socket apparatus has a support structure including a plurality of legs adapted to be inserted into apertures in the printed circuit board and be soldered in place. The bulk of the socket apparatus is elevated above the printed circuit board so that important real estate between the socket structure and the printed circuit board surface can be used for placement of circuit components in the printed circuit board. The support structure is designed such that it permits great flexibility in terms of the mounting and location of the apparatus on a printed circuit board which may have many diverse configurations for use in different types of electronic devices.

[0007] FIG. 1 is an isometric view of the rear of the socket apparatus of the present invention with portions removed, but shown mounted to a printed circuit board together with a right angle multi-pin connector and also illustrating a module adapted for insertion into the socket apparatus.

[0008] FIG. 2 is a isometric view of a front portion of the socket apparatus shown in FIG. 1 mounted to the printed circuit board and also illustrating the insertable module.

[0009] FIG. 3 is an isometric view of the front and left side of socket apparatus embodying the present invention.

[0010] FIG. 4 is a front view of the apparatus shown in FIG. 3.

[0011] FIG. 5 is a left side view of the apparatus shown in FIG. 3.

[0012] FIG. 6 is a right side view of the apparatus shown in FIG. 3.

[0013] FIG. 7 is a top view of the apparatus shown in FIG. 3.

[0014] FIG. 8 is a cross-section taken generally along the line 8—8 in FIG. 6.

[0015] FIG. 9 is an enlarged detail of a portion of the apparatus shown in FIG. 8.

[0016] Broadly stated, the present invention is directed to a socket apparatus that is adapted to receive an electronic module with the socket apparatus being installed in a host device, such as a peripheral electronic device. The socket apparatus embodying the present invention is preferably mounted to a printed circuit board having a plurality of components mounted thereon, including a connector which is adapted to receive a mating connector in the module that is to be inserted into the socket apparatus. In addition to providing support for the module and facilitating the coupling of the connectors, the socket apparatus is designed to provide a low impedance radio frequency ground path to minimize electrical interference that may detrimentally affect the operation of the host device and/or module combination. It is therefore preferable that the socket apparatus be made of conductive metal which may be relatively thin but strong and provide adequate physical support for the plug-in module.

[0017] The socket structure is designed to be mounted to the printed circuit board and provide a low impedance ground path from the structure to the printed circuit board. The unique design provides support and protection for the host electrical connector and promotes design efficiency and maximizes use of the real estate of a printed circuit board. This is because the bulk of the socket apparatus is elevated above the printed circuit board so that circuit components can be mounted in the space between the socket apparatus and the surface of the printed circuit board. The mounting of the socket apparatus to the printed circuit board enables the designer to easily design the opening in the housing or case of the host peripheral so that the module can be easily plugged in by a user. Because the socket apparatus guides the module into position so that the connectors are aligned for coupling, the tolerances of the position of the socket apparatus relative to the peripheral chassis and the outer case of the host peripheral need not be particularly tight.

[0018] Turning now to the drawings and particularly FIGS. 1 and 2, the socket apparatus embodying the present invention is indicated generally at 10 and is shown mounted to a printed circuit board 12 that is not in and of itself a part of the present invention. The printed circuit board also has a multi-pin connector 14 attached thereto, and it is a right angle connector which is accessible from the interior of the socket apparatus 10. A module 16 is shown and it has a connector 18 that is adapted to mate with the connector 14 when the module 16 is inserted into the socket apparatus 10.

[0019] Referring to the enlarged isometric view of the socket apparatus 10 shown in FIG. 3, it has an opening in the front portion through which the module 16 can be inserted, and has a flat top wall 20, a left side wall 22, a right side wall 24, a right bottom fold 26 and a left bottom fold 28. The description of the apparatus referred to in the drawings, including FIG. 3 shows a particular illustrated orientation, wherein the wall 20, for example, is referred to as the top wall. It is this orientation that provides the disclosure and support for the claims, and it should be understood that the structure of the invention may be installed in a horizontal as well as a vertical orientation or position. A support structure is attached to the bottom folds 26 and 28 and is in the form of vertical folds 30 and 32, each of which have legs 34 and 36 extending therefrom. The legs 34 have a wider top portion which creates a ledge 38 on opposite sides of the leg 34. The ledges 38 are intended to limit the insertion depth of the legs 34 as they are inserted into suitably sized apertures in the printed circuit board. The legs 34 are on the opening end portion of the socket apparatus and the position of the ledges 38 on the front of the apparatus control the elevation of the front portion of the apparatus relative to the printed circuit board.

[0020] In accordance with an aspect of the present invention, the bottom folds 26 and 28 contact the lower portion of the module 16 when it is inserted and these surfaces support the module in its elevated position relative to the printed circuit board 12. It should be appreciated that the angle of the folds 26 and 28 are intended to conform to the shape of the module 16, and may therefore vary in degree depending upon the shape of the module 16. In fact, the height of the side walls 22 and 24 may similarly be varied for similar reasons.

[0021] As previously mentioned, the depth of insertion of the legs 34 and 36 control the elevation of the socket apparatus above the printed circuit board. An important aspect of the present invention is that real estate on the printed circuit board is not significantly reduced by the presence of the socket apparatus for the reason that it is elevated above the surface of the printed circuit board so that electronic components can be mounted thereto between the apparatus and the printed circuit board. The socket apparatus is preferably manufactured from an electrically conductive material such as 6 millimeter thick cold rolled steel which is also electrically conductive and is adapted to provide a low impedance ground path from the socket apparatus 10 to the printed circuit board. In this regard, the legs 34 and 36 are preferably soldered into the printed circuit board to provide a structurally strong apparatus. It should also be appreciated that the use of relatively thin sheet metal provides greater structural support and requires less space than plastic sockets having wall thicknesses in the range of 2-3 millimeters.

[0022] It is also preferred that the apparatus embodying the present invention be made from a unitary piece of sheet metal that is stamped, bent and otherwise processed appropriately, but it is within the scope of the present invention to have multiple pieces of sheet metal or other material that are fabricated together in an appropriate manner well known to those of ordinary skill in the art.

[0023] With regard to the low impedance RFI ground path that is provided by the apparatus embodying the present invention, the side walls 22 and 24 have a lance 40 that extends inwardly a slight distance as shown in FIGS. 3, 5, 6, 8 and 9. To form the lance, the material is sheared on the top and bottom thereof and then the material between the shear lines is pressed inwardly to form the extension illustrated. The lance 40 provides a ground contact with the module 16. In this regard, a ground contact is preferably designed into the side portions of the module 16 (not shown), so that when the module is fully inserted, the ground contacts of the module will be in contact with the lances 40 and provide a good ground connection for the module 16 to be ground on the printed circuit board. The side walls 22 and 24 also have cut-outs 42 for cooperating with a latching mechanism (not shown) that is preferably provided on the module 16.

[0024] In accordance with an important aspect of the present invention and referring to the back or connector portion thereof, the socket apparatus has an end wall 44 that is connected to the top wall 20, with the end wall 44 having an approximately 45° fold portion 46 and a second vertical end fold portion 48. The end wall 44 extends over the connector 14 and at least partially electrically and mechanically shields the same. Also, the end wall has legs 50 on opposite ends thereof, with the legs 50 terminating in a ledge 52 (similar to the ledge 38 of leg 34) that is positioned to limit the depth of insertion of the legs 50 into the printed circuit board.

[0025] However, the actual depth of insertion is preferably not controlled by ledges 52 but by ledges 54 in a pair of spaced apart symmetrical rear folds 56 attached to the top wall 20. The ledges 54 are adapted to contact the top surface of the connector 14 and accurately position the socket apparatus relative to the connector as is desired.

[0026] A pair of side folds 58 are provided on each of the sides 22 and 24 for the purpose of increasing the strength of the structure and to provide a stop against over-insertion of the module 16 into the socket apparatus 10. It is also preferred that the sidewalls 22 and 24 have outwardly flared flaps 60 at the front thereof to guide insertion of the module into the socket apparatus. Similarly, the top wall 20 has an angled top flap 62 for providing a lead-in for the module 16 and the right and left bottom folds 26 and 28 have an angled flap 64 for the same purpose. It should also be appreciated that the folds 60, 62 and 64 not only provide a guide or lead-in for the module 16, but also increase the structural integrity of the portions from which they are bent.

[0027] It is also preferred that the top surface 20 have a pair of inwardly protruding dimples or embossed areas 66 which are provided to reduce the amount of movement or play that may exist for the module 16 when it is inserted.

[0028] From the foregoing, it should be understood that the robust effective solution for supporting a plug-in module in a host device such as a peripheral has been shown and described which has many advantages and desirable attributes. The socket apparatus embodying the present invention provides an effective low impedance RFI ground path, provides support to the host electrical connector and minimizes a number of parts and tolerance stack-up compared to other prior solutions. The apparatus is elevated relative to the printed circuit board so that valuable real estate on the board is not appreciably diminished by the apparatus. Moreover, the fact that the socket apparatus is mounted and fully supported by a printed circuit board requires no additional support from the host device chassis or by a cosmetic case or housing. This obviates the need for additional parts and thereby reduces the cost and minimizes issues of tolerance stack-up between mating parts on the host device. Additionally, by keeping the module support independent from the host device chassis and case, fewer design constraints are placed on the host thereby allowing the socket apparatus to be more easily incorporated into a wide variety of host devices. The socket apparatus provides for accepting module latches that provide positive retention of the module 16 in the socket apparatus 10.

[0029] While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.

[0030] Various features of the invention are set forth in the appended claims.