Patent Publication Number: US-6712624-B2

Title: Board mountable connector and board mounting structure of connector

Description:
FIELD OF THE INVENTION 
     The present invention relates to board mountable connectors and more particularly, to a mounting structure having keying features to be mounted on an edge of a board. 
     BACKGROUND OF THE INVENTION 
     Board mountable connectors are known for example as disclosed in Japanese Unexamined Patent Publication Number 10(1998)-134909. The connector of the above patent application comprises a plurality of gripper arm pairs, and the connector is secured to a circuit board by having an edge of the circuit board received in a receiving space formed by these gripper arms. To improve retention of the connector on the board, crush ribs are formed on the gripper arms. 
     In this example, the connector and the circuit board are secured by frictional engagement. Accordingly, as it is not a permanent securing means because, after use over a long period of time, the securing members may loosen. Further, in the case that the connector is intended to be provided with a keying mechanism, additional ribs that mate with the circuit board in a concave or convex manner are generally provided. In this case, it becomes necessary to provide additional space in the mounting area of the circuit board for the keying mechanism, making the mounting foot print larger. Additionally, when the connector has been mounted erroneously and needs to be removed and remounted, the crush ribs may have been permanently deformed during the first mounting preventing them from securing the connector during the remounting. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in view of the above problems, and it is an object of the present invention to provide a board mountable connector having a high retention strength, while minimizing the required mounting area on the circuit board for mounting a keying mechanism. 
     This and other objects are achieved by providing a board mountable connector having an insulative housing having a plurality of contacts, a pair of mounting portions, to be mounted near an edge of a circuit board. The circuit has a pair of openings for receiving the mounting portions. Each of the mounting portions is provided with a mounting aperture to be penetrated by a bolt for securing the insulative housing the openings in the circuit board. One of the pair of mounting portions is formed with a keying protrusion on a contact surface that contacts the circuit board to engage a slot provided at one of the openings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described by way of example with reference to the accompanying figures of which: 
     FIG. 1 is a front view of the board mountable connector according to a first embodiment of the present invention. 
     FIG. 2 is a plan view of the board mountable connector of FIG.  1 . 
     FIG. 3 is a left side view of the board mountable connector of FIG.  1 . 
     FIG. 4 is a rear view of the board mountable connector of FIG.  1 . 
     FIG. 5 is a bottom view of the board mountable connector of FIG.  1 . 
     FIG. 6 is a partial cross section of the mounting member, taken along the line  6 — 6  of FIG.  4 . 
     FIG. 7 is a partial schematic view of a board and the board mountable connector of the first embodiment to be mounted thereon. 
     FIG. 8 is a left side view of a board mountable connector according to a second embodiment of the present invention. 
     FIG. 9 is a partial cross section showing the planar shape of the keying protrusion of FIG.  8 . 
     FIG. 10 is a bottom view of a board mountable connector according to a third embodiment of the present invention. 
     FIG. 11 is a left side view of the board mountable connector of the third embodiment of the present invention. 
     FIG. 12 is a partial cross section showing the planar shape of the keying protrusion of the board mountable connector shown in FIG.  10 . 
     FIG. 13 is a partial schematic view of a board and the board mountable connector of the third embodiment to be mounted thereon. 
     FIG. 14 is a partial cross section showing a portion of the board mountable connector according to a fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The connector according to the first embodiment will now be described with reference to FIGS. 1 through 6. The connector  1  comprises an insulative housing hereinafter referred to as a housing  6 , formed integrally by an insulative synthetic material having a plurality of contacts  10  positioned therein. The housing  6  has a generally flattened substantially rectangular main body  2  and a rectangular mounting portion  4  on each side of the rear portion of the main body  2 . Pointed protrusions  8  are formed at both sides of the front end or mating portion of the connector  1 . These protrusions  8  act as guides when connector  1  mates with another connector (not shown). 
     Contacts  10  are formed so that their board contact sections  10   a ,  10   b  (see FIG. 4) protrude from the rear portion of main body  2  of housing  6  to be connected to a board P (see FIG.  7 ). These board contact sections  10   a ,  10   b  are arranged such that they are disposed in upper and lower rows, as shown in FIG. 4 so that the board P is received in between the rows. In addition, each of the board contact sections  10   a ,  10   b  are formed with a bight portion  11  protruding towards the board side to contact the board P (see FIG.  3 ). 
     The mounting portions  4  are formed of a pair of mounting portions  4   a ,  4   b . As best shown in FIG. 3, board receiving grooves  12 , are formed in the mounting portions  4 . The grooves  12  are located so that the board P is positioned in between the rows of board contact sections  10   a ,  10   b  that extend out of the rear portion of main body  2  (see FIG.  4 ). Tapered surfaces  14   a ,  14   b  are formed at portions of the grooves  12  where they open at the rear end surfaces  14  of the mounting portions  4 , to facilitate the insertion of board P. The opposing surfaces of the grooves  12  are contact surfaces  16 ,  18 , that contact and hold the board P when it is inserted into the grooves  12 . 
     Each of the mounting portions  4  is provided with a mounting aperture  20  that penetrates the two opposing contact surfaces  16 ,  18 . That is, the mounting apertures  20  are formed to penetrate upper portions  24  of the mounting portions  4  above the grooves  12  as well as lower portions  26  below the grooves  12 . The mounting apertures  20  are generally circular apertures  20   a  provided in the upper portions  24  and generally oblong mounting apertures  20   b  having semicircular inner edges (see FIG.  5 ). The oblong shape of the mounting aperture  20   b  is formed by a pin in molding die being positioned at that location during the manufacturing process of integral formation of the mounting aperture  20   b . Note that in each of the embodiments, the mounting apertures as a whole are referred to as mounting aperture  20 . 
     A keying protrusion  22  is integrally formed on the contact face  18  of the mounting portion  4   b . The keying protrusion  22  extends from the mounting aperture  20  towards the rear end surface  14  (see FIGS. 3 and 5) of the connector  1 . The keying protrusion  22  is formed on the mounting portion  4   b . The keying protrusion  22  is of approximately the same width as the diameter of the mounting aperture  20 , and the tip  22   a  is formed in an arc shape to facilitate engagement with the board P (see FIG.  5 ). The shapes of the ridge  22  and the oblong mounting aperture  20   b , as well as their relative positions, are clearly shown in FIG.  6 . 
     As shown in FIG. 4, recesses  28  are formed in the upper portions  24  of the mounting portions  4 . Nuts  30  are press-fitted within the recesses  28  (see FIG. 2, FIG.  4 ). These nuts  30  threadably mate with bolts (not shown) inserted from a lower side as shown in FIG. 4 to secure the connector  1  on the board P. The nuts  30 , as best shown in FIG. 2, are approximately octagonal in shape. When the nuts  30  are press-fitted to a predetermined position, threaded apertures  30   a  of the nuts  30  become concentric with the mounting aperture  20   a.    
     Next, the board P, on which the connector  1  is to be mounted, will be described with reference to FIG.  7 . FIG. 7 is a partial schematic view of the board P and a portion of connector  1  in accordance with the first embodiment to be mounted thereon. Note that connector  1  is shown by a broken line in the figure. In the vicinity of the edge  80  of the board P are formed openings  82 ,  85  that are in positions corresponding to the mounting apertures  20  of connector  1 . The opening  82  is circular in shape, while the opening  85  is formed as a slot having a width equal to the diameter of the opening  82 , extending in a direction perpendicular to the edge  80  and opening thereto. 
     To mount the connector  1  to the board P, the keying protrusion  22  is aligned with the opening  85 , and the connector  1  is mounted onto the board P in a manner so as to insert the edge  80  into the grooves  12 . At this point, the keying protrusion  22  is guided by the inner edge of the slot  85  as it enters the slot  85 . When the connector  1  reaches a predetermined position in relation to the board P, the opening  82 , the slot  85 , and the mounting apertures  20  become aligned. At this point it becomes possible to secure the connector  1  to the board P by inserting the bolts from a lower side as shown in FIG.  3  and FIG.  4 . If the mounting of the connector  1  is attempted erroneously, e.g., while it is upside down, the keying protrusion  22  does not enter slot  85 . Rather, as the keying protrusion  22  would be positioned on the side of opening  82 , the edge  80  of board P will interfere therewith, preventing the insertion of board P into the grooves  12 . A plurality of conductive pads  86  are formed on both sides of the board P along its edge  80 , between the opening  82  and the slot  85 . The conductive pads  86  are connected to the board contact sections  10   a ,  10   b  of the contacts  10 . More specifically, the bight portions  11  of the board contact sections  10   a ,  10   b  are connected to the conductive pads  86 . 
     Next, a connector according to a second embodiment of the present invention will be described with reference to FIG.  8  and FIG.  9 . Note that elements that are the same as those in the first embodiment have been assigned the same reference numerals. The connector  1 A has a longer keying protrusion than connector  1 . Mounting aperture  20   c  of a lower portion  126  is formed circular, similar to a mounting aperture  20   a . A portion that extends from the mounting aperture  20   c  to the rear end surface  14  is formed as a keying protrusion  22   a  having the same shape as the keying protrusion  22 . However, a ridge  22   b , of the same width as the keying protrusion  22   a , is integrally formed on an inner side of a groove  12 , the keying protrusion  22   a  and ridge  22   b  form as a whole, a long keying protrusion  122  that extends as a whole from the rear end surface  14  to the interior wall  34  of the groove  12 . In this case, when the long keying protrusion  122  enters a slot  85 , its length allows improved guidance and alignment during mating. In addition, because the mounting apertures  20  are circular, the positioning of the housing  6  becomes more accurate. Thereby, soldering paste on the conductive pads  86  is not disturbed by the board contact sections  10   a.    
     Next, a connector according to a third embodiment of the present invention will be described with reference to FIG. 10 through 12. The connector according to the third embodiment has a keying protrusion having a width thinner than the mounting apertures  20 . The keying protrusion  222  that extends in an insertion direction A on both sides of a mounting aperture  20   c  is thinner than the keying protrusion  122  described above. The keying protrusion  222  comprises a rear portion  222   a  that extends towards the rear end surface  14 , and a front portion  222   b  that extends towards the inner wall  34 . The keying protrusion  222  is aligned with the mounting aperture  20   c , and is divided at the mounting aperture  20   c  of the connector  1 B. 
     Next, the relative positions of the connector  1 B and a board P during mounting will be described with reference to FIG.  13 . The board P is provided with openings  82  and  84  in positions corresponding to mounting apertures  20 . A slot  88  is aligned with opening  84 . This slot  88  is formed to be complimentary with the keying protrusion  222 . When the connector  1 B is to be mounted onto the board P, the keying protrusion  222  is guided by, and enters, slot  88  as described above. Because as the rear portion  222   a  of the keying protrusion  222  is longer than the diameter of the opening  84 , shifting of the rear portion  222   a  within the opening  84  during insertion is prevented. Accordingly, smooth installation and accurate positioning of the connector  1 B is ensured. 
     Next, an alternate embodiment of the thin keying protrusion in a connector  1 C according to a fourth embodiment of the present invention will be described with reference to FIG.  14 . The connector  1 C of this embodiment is a combination of the mounting aperture  20   b  of the first embodiment and a portion of the thin keying protrusion  222  of the third embodiment. The structure of the connector  1 C combines the oblong mounting aperture  20   b  that extends to the inner wall  34  as shown in FIG.  5  and the rear portion  222   a  of the keying protrusion  222  that extends from the edge of the mounting aperture  20   b  to the rear end surface  14 , as shown in FIG.  12 . The connector  1 C is also mounted on the same board P. As the rear portion  222   a  is longer than the diameter of the opening  84  as in the previous embodiment, similar improvements in guiding and positioning accuracy are obtained. In the fourth embodiment, as the mounting aperture  20   b  is an oblong aperture and there is no protrusion formed on a forward portion thereof, the structure of the molding dies are relatively simplified. 
     Because the board mountable connector according to the present invention is provided with mounting apertures for receiving the bolt, while one of the pair of mounting portions is provided with the keying protrusion on the contact surface thereof, the retention strength is improved due to the use of bolts, while the mounting space required can be minimized due to the combination of the keying member and the mounting member. 
     Where the mounting portions have grooves for receiving the circuit board, the mounting apertures are formed to penetrate the pairs of opposing surfaces that define the grooves. The keying protrusion is formed as a protrusion that extends in a mounting direction of the insulative housing to the circuit board on a contact surface which is one of the opposing surfaces that define one of the grooves aligned with the mounting aperture. The retention strength is therefore further improved due to the groove and mounting portions, while the required mounting area can be further minimized due to the mounting aperture and the keying protrusion being formed at the same position. In addition, the connector may be smoothly mounted onto the circuit board because the keying protrusion formed as a ridge that extends in a mounting direction of the insulative housing to the circuit board acts as a guide when the connector is mounted onto the circuit board. 
     If the keying protrusion is formed so that its width is thinner than the mounting aperture and its length is longer than the diameter of the opening of the circuit board, the guide function during the mounting operation can be further improved, thereby improving the reliability of the electrical connection. 
     The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.