EDGE-MOUNTED ELECTRICAL CONNECTOR

Abstract: An electrical connector for providing electrical contact between a PC board and a removable component comprises an insulative housing with a longitudinal opening to receive the edge of the board, and a plurality of spring contact elements mounted in the housing, each having one end extending into the opening to provide an internal contact for a termination on the board. The opening can be configured for any of several different edge configurations for the board: a straight edge, a recessed edge, or an edge with a central protruding tab. The housing includes an array of elongate apertures in one wall, and a portion of each element protrudes through one of the apertures, thereby forming an external contact for a termination on the removable component. The internal contacts can be configured either for a solder connection to the terminations on the board, or a spring-biased frictional connection thereto. In one embodiment, the apertures are in the housing wall opposite the opening, so that the external contacts extend outwardly from the edge of the board, whereby the external contacts lie in substantially the same plane as the board, tangentially to the edge of the board. In another embodiment, the apertures are located in a housing wall that lies substantially parallel to the plane of the board, whereby the external contacts extend outwardly from the plane of the board, thereby lying in a plane that is substantially parallel to the plane of the board.

Description: EDGE-MOUNTED ELECTRICAL CONNECTOR Background of the Invention The present invention relates generally to the field of electrical connectors. More specifically, it relates to connecting devices that provide electrical connection between a printed circuit board and a separate electrical component, or between first and second printed circuit boards. As the use of printed circuit boards ("PC" boards) has become routine in electronic apparatus, a multitude of devices that provide a removable electrical interconnection between adjacent PC boards, and between a PC board and a separate component, have been devised. Examples of such prior art devices are found in the following U.S. patents: 3,715,706 - Michel et al. 4,161,346 - Cherian et al. 4,505,529 - Barkus 4,511,196 - Schuler et al. 4,553,192 - Babuka et al. 4,738,625 - Burton et al. 4,983,126 - Busse et al. 5,035,629 - Matsuoka 5,069,627 - Buck et al. 5,147,207 - Mowry 5,199,889 - McDevitt, Jr. While many prior art devices have served well in a number of applications, there is still a need for improvement in addressing a number of problems. For example, there is a need to simplify such electrical connecting devices and to reduced their costs of manufacture. Furthermore, there is a need to provide connecting devices that do not necessitate either modification of the PC boards or the addition of other mounting structure, thereby further reducing costs and simplifying the overall manufacturing process of the electronic apparatus. In addition, the connecting devices need to take as little space as possible, thereby allowing overall space savings for the electronic apparatus, and denser packaging of components and PC boards. Moreover, the connecting devices need to provide a reliable, secure electrical connection, and, in many applications, to provide a connection that is able to withstand at least moderate amounts of physical shock and 4 and other advantages will be more readily appreciated from the detailed description that follows. Brief Description of the Drawings Figure 1 is a cross-sectional view of an electrical connecting device in accordance with a first preferred embodiment of the present invention, showing the establishment of electrical contact between a PC board and an end-terminal electrical component; Figure 1 A is a perspective view of a spring contact element of the type employed in the device of Figure 1 ; Figure 2 is a cross-sectional view of a modified form of the first preferred embodiment, showing the establishment of electrical contact between a PC board and a side-terminal component; Figure 3 is a side elevational view of the form of the invention shown in Figure 2, in contact with the PC board and the side-terminal component; Figure 4 is a cross-sectional view of another modified form of the first preferred embodiment, showing the establishment of electrical contact between a PC board and a side-terminal component; Figure 5 is a perspective view of the connecting device of Figure 1 , showing the device being connected to a flush-edged PC board; Figure 6 is a perspective view of a connecting device in accordance with the first preferred embodiment, but slightly modified for use with a tab-edged PC board, illustrated therewith; Figure 7 is a perspective view of the connecting device of Figure 1, showing the device being connected to a recessed-edge PC board; Figure 8 is a perspective view of a connecting device in accordance with a second preferred embodiment, showing the device being connected to a flush-edged PC board; Figure 9 is a perspective view of a modified form of the second the board. In a second preferred embodiment, the apertures are located in one of the housing walls that lies substantially parallel to the plane of the fixed board. In this second embodiment, the external contacts extend outwardly from the plane of the board, thereby providing contact points that lie in a plane that is substantially parallel to the plane of the board. In either embodiment, the internal contacts can be configured either for a solder connection to the terminations on the fixed board, or a "slip- on", spring-biased frictional connection thereto, depending upon whether it is desired to create a permanent connection or a temporary, removable connection between the fixed board and the connecting device. In addition, in those configurations in which a frictional, slip-on connection is employed, the connecting device can optionally be removable secured to the fixed board either by removable fasteners (e.g., screws), or by means of integral clips provided on the housing on opposite ends of the longitudinal front opening, whereby the clips are engageable with registering apertures in the board. Furthermore, in either embodiment, the longitudinal opening along the front of the housing can be configured for any of several different edge configurations for the fixed board: a straight (flush) edge, an edge with a central recess, or an edge with a central protruding tab. It will be seen that the present invention provides a stable, secure electrical contact between a fixed PC board and a removable PC board or a removable component without occupying a significant amount of space, without requiring modifications to the fixed board or to the removable board or the removable component, and without requiring any additional mounting structure. Furthermore, by providing electrical contact at the edge of the fixed board, the maximum amount of surface area of the board is useable for components and circuitry. Furthermore, the connecting devices in accordance with the present invention allow for easy removal of the removable board or component, they are simple to install on the fixed board, and they are relatively simple and economical to manufacture. These 6 oriented substantially perpendicular to the front slot 20, and thus, as oriented in the drawings, substantially vertically. A plurality of spring contact elements 26 are mounted in the interior of the housing 16. As best shown in Figure 1A, each of the spring contact elements 26 is formed of a strip of conductive metal that is bent to form an acute angle having an apex 27. When so bent, each contact element 26 has a shorter leg 28 terminating in a first or free end 30, and a longer leg 32, the end portion of which is turned down to form a substantially horizontal internal contact 34. A pair of upturned tabs 36 are advantageously provided on the longer leg 32. The housing 16 has a thick upper wall portion 38 into which the contact elements 26 may be installed, as by molding the housing 16 around the tabs 36, or by crimping the tabs 36 into conforming recesses 40 in the upper wall portion 38, as shown in Figure 1. Other functionally equivalent means for securing the contact elements 26 in the housing 16 will readily suggest themselves to those skilled in the art. When the contact elements 26 are installed, the apex 27 of each contact element 26 extends rearwardly through one of the elongated apertures 24 in the rear wall 22 of the housing 16, thereby forming an external contact that is positioned for establishing electrical contact with a terminal 41 on the electrical component 14 (Figure 1). In this embodiment, the external contacts 27 extend outwardly or rearwardly from the edge of the board 12, whereby the external contacts 27 provide contact points that lie in substantially the same plane as the board, tangentially to the edge of the board. In the embodiment of Figures 1, 5, and 7, the internal contacts 34 of the contact elements 26 are bent rearwardly, toward the interior cavity 18 of the housing 16 to form an array of substantially flat contact surfaces enclosed within the cavity 18. In this configuration, the internal contacts 34 are suitable for being connected by solder junctions (not shown) with termination pads 42 (Figures 5 and 7) on the board 12. Alternatively, the preferred embodiment, along with a flush-edged PC board to which the connecting device is being attached; Figure 10 is a cross-sectional view of a connecting device in accordance with the second preferred embodiment, showing a first contact configuration; Figure 11 is a cross-sectional view of a connecting device in accordance with the second preferred embodiment, showing a second contact configuration; Figure 12 is a cross-sectional view of a connecting device in accordance with the second preferred embodiment, showing a third contact configuration; Figure 13 is a cross-sectional view of the connecting device of Figure 8, showing the device attached to a PC board; and Figure 14 is a cross-sectional view of the connecting device of Figure 9, showing the device attached to a PC board. Detailed Description of the Preferred Embodiments Referring first to Figures 1, 5, and 7, an electrical connecting device 10, in accordance with a first preferred embodiment of the present invention, is shown providing an electrical connection between a printed circuit board or printed wiring board 12 (hereinafter referred to as the "board 12") and an electrical component 14, which may be, as shown in Figure 1, and end-terminal battery. The connecting device 10 comprises a hollow insulative housing 16 defining an interior cavity 18 accessed by a longitudinal opening or slot 20 that extends along the entire length of its front side. As is shown in Figures 5 and 7, the housing 16 has a pair of opposed side walls 21 (only one of which is shown in the drawings), and the front opening or slot 20 extends through the side walls 21. As is also shown in Figures 5 and 7, the housing 16 has a rear wall 22 that is provided with an array of elongate apertures 24, the longer dimension of which is 8 27 in electrical contact with a side terminal 40' on a side-terminal electrical component 14'. Figure 4 shows another connector device 10" that is substantially identical to the above-described devices, except for the configuration of the connector elements. The modified connector device 10" of Figure 4 includes modified contact elements 26", wherein the longer leg 32 of each contact element 26" terminates in an internal contact that is bent forwardly to form a flat, forwardly-extending termination 50 that is adapted for electrical connection to the termination pad 42 by a solder junction (not shown). As with the above-described connector devices 10 of Figure 1 and 10' of Figures 2 and 3, the modified connector device 10" can be used with straight-edged, recessed-edge, and tab-edged boards, although, with the last- named, the solid-sided housing 16' of Figure 6 is advantageously used. The modified connector device 10" is shown with its external contact 27 establishing electrical contact with a side terminal 41" on a side- terminal electrical component 14". It should be noted that all of the above described connector devices 10, 10', and 10" can be used with either end-terminal or side-terminal electrical components, depending on the application. The term "electrical component" should be construed in its broadest context, to include discrete components, IC's, and removable circuit boards. Figures 8-14 illustrate a second preferred embodiment of the present invention. Referring first to Figures 8 and 13, a connector device 60, in accordance with the second embodiment, is shown with a printed circuit board or printed wiring board 62. The connector device 60 comprises a hollow insulative housing 64 defining an interior cavity 66 accessed by a longitudinal opening or slot 68 that extends along the entire length of its front side. The housing 64 has a solid rear wall 70 and a pair of opposed side walls 72 (only one of which is shown in the drawings), with the front opening or slot 68 extending through the side walls 72. The housing 64 has a top wall 74 that is provided with an array of elongate apertures 76, the internal contacts can be installed so as to have a spring bias, whereby they can establish a "slip-on/slip-off ' frictional contact with the termination pads 42. In Figure 5, the board 12 has a straight or flush edge 44, while in Figure 7, the board 12 has an edge with a central recess 46. In either case, the device 10 can be dimensioned to fit onto the board edge so as to establish electrical contact between the internal contacts 34 and the termination pads 42. Figure 6 shows a modified housing 16', in which the front slot 20 (not shown in this figure) does not extend all the way across the front of the housing 16', so that the housing 16' has solid, unbroken side walls 21 '. This housing configuration is best suited for a board 12 with an edge having a protruding central tab or extension 48. Figures 2 and 3 show a connector device 10' that is substantially identical to the connector device 10 described above, except for having modified contact elements 26'. The longer leg of each modified contact element 26' terminates in an extended internal contact portion that is bent to extend first rearwardly, then downwardly, and then forwardly to form an internal contact in the configuration of a terminal clip 49. The terminal clips 49 are thus configured for frictional engagement with the edge of the board 12 so as to establish electrical contact with the termination pads 42 thereon. Thus, the modified connector device 10' can establish good electrical connections with the termination pads without the use of solder, so that the connector device 10' is readily removable. The modified connector device 10' is thus well-suited for applications in which a permanent connection the board 12 is not desired. As with the embodiment of Figure 1, the modified connector device 10' can be used with straight-edged, recessed-edge, and tab-edged boards, although, with the last-named, the solid-sided housing 16' of Figure 6 is advantageously used. The modified connector device 10' is shown with its external contact 10 the housing 64' that underlies the slot 68' and that forms a seat 96 for the board 62'. The board 62' has a pair of holes 98 located so that, when the board 62' is fully inserted into the housing cavity through the front slot 68' so as to abut against the step 90', they are aligned with the countersunk holes 92 and the threaded holes 94. With the board holes 98 so aligned with the housing holes 92, 94, a screw 100 may be installed through each aligned set of holes 92, 94, 98 to secure the connector device 60' to the board 62' in the proper position. It will be appreciated that other types of through-hole fasteners, such as rivets (not shown) can be used in place of the screws 100 for positioning and securing the housing to the board. If, for example, rivets are used, the board holes would, of course, not be threaded. Both the connector device 60 of Figures 8 and 13 and the modified connector device 60' of Figures 9 and 14 include a plurality of spring contact elements 102 mounted in the interior of the housing so that a central portion of each contact element 102 extends upwardly from one of the elongate apertures 76 to form an external contact 104 that is positioned for establishing electrical contact with a terminal on an electrical component (not shown). Thus, in this embodiment, with the elongate apertures 76 being located in a housing wall that lies substantially parallel to the plane of the board 62, the external contacts 104 extend outwardly or upwardly from the plane of the board 62, thereby providing contact points that lie in a plane that is substantially parallel to the plane of the board 62. The following description of the contact elements will be in the context of the connector device 60 of Figures 8 and 13, but it should be understood that any of the contact elements described below can be readily employed in the modified device 60' of Figures 9 and 14. As best shown in Figure 10, each spring contact element 102 comprises a bent strip of conductive metal having a first or forward portion 106 that extends forwardly and downwardly from the above-mentioned longer dimension of which is substantially parallel to the side walls 72. In the connector device 60 of Figure 8, the housing 64 includes a pair of clips 78, that are advantageously formed integrally with opposite ends of the rear wall 70. Each of the clips 78 extends forwardly from the rear wall 70, substantially parallel to the adjacent one of the side walls 72. Each clip 78 terminates in a downwardly-depending finger 80 (only one of which is shown in the drawings). As shown in Figure 13, each of the fingers 80 has a leading edge 82 that slopes downwardly and rearwardly, and a trailing edge 84 that is substantially vertical. Alternatively, the clips 78 may be formed as discrete metal or plastic elements that can be attached to the housing 64 by any suitable means, as would be well-known in the art. The board 62 has a pair of holes or recesses 86 on opposite sides of its edge 88. As shown in Figure 13, when the board 62 is inserted into the front slot 68 of the connector device 60, the board edge 88 pushes against the leading edges 82 of the fingers 80, thereby pushing the clips 78 upwardly to allow the full forward insertion of the board edge 88 into the housing cavity 66 through the slot 68. The interior of the housing 64 has a step 90 against which the board edge 88 abuts when it is fully inserted. At this position, the holes or recesses 86 underlie the fingers 80, whereby the clips 78 are permitted to snap resiliently back downwardly so as to engage each of the fingers 88 in its associated recess or hole 86. This cooperative engagement between the clips 78 and the board 62 facilitates the proper positioning of the connector device 60 on the board 62, and it provides a more secure attachment of the connector device 60 to the board 62. An alternative mechanism for positioning and securing the housing and the board is shown in Figures 9 and 14. In this variant, a modified connector device 60' includes a modified housing 64' that has a pair of countersunk holes 92 through the top wall 74' near the side walls 72' (only one of which is shown). The countersunk holes 92 are aligned with a pair of internally-threaded holes 94 (only one of which is shown) in a portion of 12 configurations to suit different applications. Likewise, the specific housing configurations described above and shown in the drawings are exemplary only, and many other configurations may be found to be suitable. These and other modifications that may suggest themselves to those skilled in the pertinent arts should be considered within the spirit and scope of the present invention, as defined in the claims that follow. central portion and that is molded or inserted into the housing 64 forward of the elongate aperture 76 from which the external contact 104 extends. Extending rearwardly and downwardly from the central portion is rearward portion 108 that terminates in a free end 110 that is spring-biased to resiliently abut against the underside of a lip 112 that defines the rear end of the elongate aperture 76. The forward portion 106 terminates in an end that forms an internal contact 114, which, as shown in Figure 10, comprises a substantially flat, rearwardly-extending contact surface lying substantially within the slot 68. In this configuration, the internal contacts 114 are suitable for being connected by solder junctions (not shown) with termination pads 1 16 on the board 62. Figure 11 shows a modified spring contact element 102', which includes a modified internal contact 114'. The modified internal contact 114' is formed as a forwardly-extending resilient spring contact, situated for at least most of its length within the slot 68. This modified internal contact 114' is suitable for a frictional engagement with the termination pads 116. Another modified spring contact element 102", shown in Figure 12, includes a modified internal contact 114" that is formed as a rearwardly- extending resilient spring contact, situated almost entirely within the housing cavity 66. This second modified internal contact 1 14" is also suitable for frictional engagement with the termination pads 116. Although two preferred embodiments of the invention have been described above, along with several modifications, it will be appreciated that further modifications and variations may suggest themselves to those skilled in the pertinent arts. For example, the spring contact elements 26, 26', and 26" of the first preferred embodiment may be readily modified to provide an internal contact on both of the planar surfaces of the board 12. Furthermore, the internal contacts provided by any of the spring contact elements described above may be formed in any of a wide variety of 14 5. The connecting device of Claim 3, wherein the housing includes a front portion between the array of apertures and the front opening, and wherein the contact elements are fixed to the front portion. 6. The connecting device of Claims 1, 2, 3, 4, or 5, wherein the internal contact includes a substantially flat, planar end portion configured to establish a surface-to-surface contact with one of the termination pads. 7. The connecting device of Claims 1, 2, or 4, wherein the internal contact is configured as a clip that is engageable with the edge of the circuit board. 8. The connecting device of Claims 1 , 2, 3, 4, or 5, wherein the internal contact includes a spring-biased end portion. 9. The connecting device of Claims 1, 3, or 5, wherein the housing includes a rear wall opposite the front opening, a pair of opposed side walls, and a clip extending from the rear wall along each of the side walls, whereby the clip is removably engageable with the circuit board when the circuit board is inserted into the front opening. 10. The connecting device of Claims 1, 3, or 5, wherein the housing is attachable to the circuit board by fasteners. 1 1. An electrical connecting device attachable to a circuit board having an edge and a plurality of termination pads adjacent the edge, the connecting device comprising: an insulative housing having a front opening configured to receive the edge of the circuit board, and a rear wall with an array of apertures; and a plurality of discrete contact elements mounted in the housing, each of which has a first portion formed as an internal contact located within the front opening so as to establish electrical contact with one of the termination pads when the edge of the circuit board is inserted into the front opening, and a second portion that extends through one of the apertures to form a spring-biased external

Claims: WHAT IS CLAIMED IS: 1. An electrical connecting device attachable to a circuit board having an edge and a plurality of termination pads adjacent the edge, the connecting device comprising: an insulative housing having a front opening configured to receive the edge of the circuit board, and a wall with an array of apertures; and a plurality of discrete contact elements mounted in the housing, each of which has a first portion formed as an internal contact located within the front opening so as to establish electrical contact with one of the termination pads when the edge of the circuit board is inserted into the front opening, and a second portion that extends through one of the apertures to form a spring-biased external contact. 2. The connecting device of Claim 1, wherein the wall is substantially perpendicular to the plane of the circuit board when the circuit board is inserted into the front opening, whereby the external contacts formed by the contact elements provide a plurality of electrical contact points that, when the circuit board is inserted into the front opening, lie in substantially the same plane as the circuit board and are substantially tangential to the edge thereof. 3. The connecting device of Claim 1, wherein the wall is substantially parallel to the plane of the circuit board when the circuit board is inserted into the front opening, whereby the external contacts formed by the contact elements provide a plurality of electrical contact points that, when the circuit board is inserted into the front opening, lie in a plane that is substantially parallel to the plane of the circuit board. 4. The connecting device of Claim 2, wherein the wall is a first wall, and wherein the housing has a second wall that is substantially parallel to the plane of the circuit board when the circuit board is inserted into the front opening, and wherein die contact elements are fixed to the second wall. 16 spring-biased external contact; wherein the top wall is substantially parallel to the plane of the circuit board when the circuit board is inserted into the front opening, whereby the external contacts formed by the contact elements provide a plurality of electrical contact points that, when the circuit board is inserted into the front opening, lie in a plane that is substantially parallel to the plane of the circuit board. 17. The connecting device of Claim 16, wherein the housing includes a front portion between the array of apertures and the front opening, and wherein the contact elements are fixed to the front portion. 18. The connecting device of Claims 16 or 17, wherein the internal contact includes a substantially flat, planar end portion configured to establish a surface-to-surface contact with one of the termination pads. 19. The connecting device of Claims 16 or 17, wherein the internal contact includes a spring-biased end portion. 20. The connecting device of Claims 16 or 17, wherein the housing includes a rear wall opposite the front opening, a pair of opposed side walls, and a clip extending from the rear wall along each of the side walls, whereby the clip is removably engageable with the circuit board when the circuit board is inserted into the front opening. 21. The connecting device of Claims 16 or 17, wherein the housing is attachable to the circuit board by fasteners. contact; wherein the rear wall is substantially perpendicular to the plane of the circuit board when the circuit board is inserted into the front opening, whereby the external contacts formed by the contact elements provide a plurality of electrical contact points that, when the circuit board is inserted into the front opening, lie in substantially the same plane as the circuit board and are substantially tangential to the edge thereof. 12. The connecting device of Claim 11, wherein the housing has a second wall that is substantially parallel to the plane of the circuit board when the circuit board is inserted into the front opening, and wherein the contact elements are fixed to the second wall. 13. The connecting device of Claims 11 or 12, wherein the internal contact includes a substantially flat, planar end portion configured to establish a surface-to-surface contact with one of the termination pads. 14. The connecting device of Claims 11 or 12, wherein the internal contact is configured as a clip that is engageable with the edge of the circuit board. 15. The connecting device of Claims 1 1 or 12, wherein the internal contact includes a spring-biased end portion. 16. An electrical connecting device attachable to a circuit board having an edge and a plurality of termination pads adjacent the edge, the connecting device comprising: an insulative housing having a front opening configured to receive the edge of the circuit board, and a top wall with an array of apertures; and a plurality of discrete contact elements mounted in the housing, each of which has a first portion formed as an internal contact located within the front opening so as to establish electrical contact with one of the termination pads when the edge of the circuit board is inserted into the front opening, and a second portion that extends through one of the apertures to form a

Inventors: KWIAT KAROL, KWIAT, KAROL
Applicants: BOURNS INC, BOURNS, INC.
Application year: 1997
Main classification: H01R9
IPC codes: H01R12