Modular plug and printed circuit connector
BACKGROUND OF THE INVENTION 
     The present invention generally relates to connectors, and more particularly to a connector which is used for connecting a telephone set to a telephone line. 
     Conventionally, connectors having fundamental parts thereof standardized in conformance with the FCC standard or the like are used to connect telephone sets to telephone lines. An example of the connector of this kind has a box-shaped housing with a plug inserting opening on the front surface of the housing. When the telephone set is connected to the telephone line, a plug which is provided on an end of a telephone line is inserted into the plug inserting opening. A plurality of contact pins are embeddedly provided on the housing so that one end of each of the contact pins project from the bottom of the housing to constitute a terminal part and the other end of each of the contact pins project within the plug inserting opening of the housing to constitute a contact part. A plurality of electrodes provided on the plug make contact with the contact part when the plug is inserted into the plug inserting opening of the housing. The connector is placed on a printed circuit board which is secured to a main telephone body, in such a manner that the plug inserting opening is exposed to the outside of the main telephone body. The terminal part constituted by the contact pins projecting from the bottom of the housing is soldered to respective circuit patterns on the printed circuit board. 
     In this arrangement of the conventional connector, the overall height of the connector in use is the sum of the height of the connector itself and the thickness of the printed circuit board, and is relatively large. For this reason, it is difficult to accommodate connector within a limited space. Consequently, there is a problem in that it is difficult to accommodate the connector within a telephone set having a thin configuration. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide a novel and useful connector in which the problems described heretofore are eliminated. 
     Another and more specific object of the present invention is to provide a connector having a slit part formed at an intermediate height position of a connector housing, which slit part is inserted with a printed circuit board so as to connect the connector and the printed circuit board. According to the connector of the present invention, the thickness of the printed circuit board is included in the height of the connector itself in a state where the connector and the printed circuit board are connected. Hence, it is possible to accommodate the connector within a space having a height corresponding to the height of the connector itself, which height of the connector itself includes the thickness of the printed circuit board. Therefore, the connector of the present invention can be applied to a telephone set having such a thin configuration that an internal space thereof is small. 
     Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a first embodiment of a connector of the present invention; 
     FIGS. 2 through 5 are respectively a front view, a plan view, a rear view and a side view of the connector shown in FIG. 1; 
     FIG. 6 is a cross section of the connector along a line VI--VI in FIG. 2; 
     FIGS. 7A and 7B are respectively a plan view and a front view of a part of a printed circuit board which is connected to the connector shown in FIG. 1; 
     FIGS. 8A and 8B are respectively perspective views of modifications of contact pins which may be applied to the connector shown in FIG. 1; 
     FIGS. 9 and 10 are respectively a front view and a side view of a second embodiment of the connector of the present invention; 
     FIG. 11 is a cross section of the connector along a line XI--XI in FIG. 9; 
     FIGS. 12, 13 and 14 are respectively a front view, a plan view and a side view of a third embodiment of the connector of the present invention; 
     FIG. 15 is a cross section showing the connector along a line XII--XII in FIG. 12; 
     FIGS. 16 through FIG. 19 are respectively a front view, a plan view, a rear view and a side view of a fourth embodiment of the connector of the present invention; 
     FIG. 20 is a cross section of the connector along a line XX--XX in FIG. 16; and 
     FIG. 21 is a cross section showing a part of the connector in FIG. 20 on an enlarged scale showing the setting state of a movable member when the printed circuit sheet is inserted into the connector. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1 through 6 respectively show a first embodiment of the connector of the present invention. A connector 10 comprises an approximately box-shaped connector housing 11 having a width W and a height H, and six contact pins 12 mounted on the housing 11. The six contact pins 12 are electrically conductive members. The housing 11 is a symmetrical structure with respect to the right and left thereof. 
     The box-shaped housing 11 is made of formed plastics. The housing 11 is provided with a plug inserting opening 14 on the front surface thereof. A plug 13 provided at an end of a telephone line is inserted into the plug inserting opening 14 as indicated by a two-dot chain line in FIG. 6. The housing 11 is provided with a slit 16 at an intermediate part of the rear surface thereof. A printed circuit board 15 shown in FIGS. 7A and 7B is inserted into the slit 16. The slit 16 cuts into the side surfaces of the housing 11 for a length D which corresponds to the depth of the insertion of the printed circuit board 15 with respect to the housing 11. The plug inserting opening 14 is provided, as in the case of the conventional connector, with steps 14a and 14b for guiding the plug 13, and stoppers 14c and 14d for locking the inserted plug 13 within the plug inserting opening 14. 
     Ribs 17a, 17b, 18a and 18b are formed on the outer side walls of the housing 11 at positions corresponding to the slit 16. The printed circuit board 15 is pinched between a first pair constituted by the ribs 17a and 17b and a second pair constituted by the ribs 18a and 18b. The upper ribs 17a and 18a are provided with arms 19 and 20 which extend along the outer side walls of the housing 11, respectively. At the distal end of the arms 19 and 20 are provided projections 19a and 20a, respectively, for engaging the inserted printed circuit board 15. The arms 19 and 20 are shaped so that the arms 19 and 20 can be deformed resilently. 
     The upper ribs 17a and 18b and the lower ribs 17b and 18b are disposed in a parallel relationship to each other, and the lower ribs 17b and 18b are shorter than the corresponding upper ribs 17a and 18a as shown in FIG. 5. The lower ribs 17b and 18b terminate at positions which are slightly offset to the front of the housing 11 with respect to the positions of the respective projections 19a and 20a. Sloping surfaces 17b-1 and 18b-1 are formed on the lower ribs 17b and 18b where the lower ribs 17b and 18b terminate. 
     Six narrow grooves are formed on the upper surface, front surface and the rear surface of the housing 11. The six narrow grooves are disposed in parallel relationship to each other for accommodating the six contact pins 12. The contact pins 12 are not rod-shaped members having circular cross sections but are flat elongated members which are inexpensive compared to the former. The six contact pins 12 are fitted into the respective six grooves and are bent along the outer surface of the housing 11. The contact pins 12 penetrate holes 23 which are provided at the upper surface of the housing 11 near the front surface of the housing 11. U-shaped bent parts 12a of the contact pins 12 are forcibly inserted into depressions 23 provided on the rear surface of the housing 11. The pins 12 are secured to the housing 11 at two positions, that is, at the front surface and the rear surface of the housing 11. 
     As shown in FIG. 6, one end of each of the contact pins 12 projects into the plug inserting opening 14 and a first contact part 12b is constituted by the one end of each of the contact pins 12. The first contact part 12b can make contact with the plug 13. The other end of each of the contact pins 12 is exposed at the slit 16 and a second contact part 12c is constituted by the other end of each of the contact pins 12. The second contact part 12c can make contact with contacts 24 provided on the printed circuit board 15. The second contact parts 12c comprises projections 12c-1 for ensuring positive electrical contact. 
     The printed circuit board 15 is secured within a main body telephone set. As shown in FIGS. 7A and 7B, the printed circuit board 15 has the plurality of contacts 24 at an inner part 15b of an U-shaped cutout 15a. The width X of the cutout 15a is slightly larger than the width W of the housing 11 so as not to interface with the insertion of the printed circuit board 15 into the housing 11. The printed circuit board 15 also has a pair of openings 15c and 15d at the left and the right side of the U-shaped cutout 15a. 
     The above mentioned connector 10 accommodates the above mentioned part 15b of the printed circuit board 15 within the slit 16 when the printed circuit board 15 is inserted into the housing 11. The projections 19a and 20a engage with the respective openings 15c and 15d and lock the inserted printed circuit board 15 to the housing 11. Both side edges 15e and 15f of the U-shaped cutout 15a of the printed circuit board 15 are supported between the pair constituted by the ribs 17a and 17b and the pair constituted by the ribs 18a and 18b. The mounting of the printed circuit board 15 to the housing 11 is easily performed by a simple insertion of the circuit board 15 into the housing 11 and requires no soldering. 
     The mounting of the printed circuit board 15 to the housing 11 can be performed by first bending the arms 19 and 20 upwardly, making the projections 19a and 20a contact the upper surface of printed circuit board 15 in vicinities of the side edges 15e and 15f, and then fully inserting the printed circuit board 15 into the housing 11. During the insertion, the printed circuit board 15 is pushed downwardly by the projections 19a and 20a. Since the lower ribs 17b and 18b do not extend up to the positions corresponding to the projections 19a and 20a, the portion of the printed circuit board 15 which is adjacent to the cutout 15a is slightly bent downwardly. The bends in the arms 19 and 20 are reduced by the amount of the slight bend of the printed circuit board 15, the urging forces exerted by the projections 19a and 20 on the upper surface of the printed circuit board 15 are also reduced. Thus, the frictional force between the printed circuit board 15 and the projections 19a and 20a is reduced, and only a small force is required to insert the housing 11 into the circuit board 15. The bent end part of the printed circuit board 15 is guided along the sloping surfaces 17b-1 and 18b-1 of the ribs 17b and 18b, and is inserted between the ribs 17a and 17b and the ribs 18a and 18b. Hence, the insertion of the printed circuit board 15 into the connector 10 is carried out smoothly. 
     In the state where the connector 10 and the printed circuit board 15 are secured together, the projections 12c-1 of the second contact part 12c make contact with the contacts 24 of the printed circuit board 15. The connector 10 which is secured to the printed circuit board 15 is assembled within the main telephone body so that the entrance portion of the plug inserting opening 14 is exposed to the outside of the telephone set at an appropriate part, such as the rear surface of the main telephone body. 
     The plug 13 provided at the end of the telephone line is inserted into the plug inserting opening 14 under the guidance of the steps 14a and 14b as shown in FIG. 6. When the plug 13 is fully inserted, the plug 13 is locked by the stoppers 14c and 14d. As indicated by a two-dot chain line in FIG. 6, the first contact part 12b of the contact pins 12 is bent by the contact between the contacts (not shown) of the plug 13. In this way, the electrical contact is achieved between the telephone set and the telephone line. 
     According to the connector 10 having the construction described heretofore, the thickness t of the printed circuit board 15 is included in the overall height H of the connector 10. Therefore, the overall thickness H of the connector 10 is equal to the height of the housing 11. Thus, in order to accommodate the connector 10 and the printed circuit board 15, it is sufficient to have the space with the height H. The connector according to the present invention is therefore suitable for use in the telephone sets because of thin configurations. 
     As an alternative to the contact pins 12, one can use other contact pins 12A as shown in FIG. 8A. Instead of the U-shaped bent parts 12a, each of the contact pins 12A has a widened part 12d which is slightly wider than the width of the narrow grooves 21 into which the contact pins 12A are fitted. The advantage of using the contact pins 12A is that it is not necessary to form the U-shaped bent parts 12a as in the case of the contact pins 12 by means of press forming, and the fabrication cost is reduced. 
     It is further possible to use contact pins 12B shown in FIG. 8B instead of the contact pins 12. The contact pins 12B are identical to the contact pins 12A except for the widened part 12e which is only formed on a part of each of the contact pin 12B. The widened part 12e of each of the contact pins 12B can easily be pressed into the narrow groove 21 and secured firmly therein, as in the case of the contact pins 12A. 
     Next, descriptions will be given with respect to other embodiments of the connector of the present invention in conjunction to FIGS. 9 through 21. The constructions of the connectors in these embodiments are basically the same as those described in the first embodiment. Therefore the parts or components which are already described in FIGS. 1 through 7 are designated by the same reference numerals with or without the addition of a subscript A, B, C, D or E and the description thereof will be omitted. 
     FIGS. 9 through 11 show a connector 30 which is the second embodiment of the present invention. In the connector 30, a slit 16A is provided at the rear surface of a connector housing 11A near the upper surface. In this embodiment, the length of contact pins 12C which run vertically at the rear surface of the connector housing 11A is short. The contact pins 12A are not provided with the U-shaped bent parts in contrast with the contact pins 12 in the first embodiment. The housing 11A is also not provided with the depression in the rear surface in contrast to the housing 11 in the first embodiment. In this configuration, the contact pins 12A can be firmly secured to the housing 11A without the U-shaped bent parts 12a and the depressions 23 which are employed in the first embodiment for the purpose of securing the contact pins 12 to the housing 11. 
     FIGS. 12 through 15 show a connector 40 which is the third embodiment of the present invention. In the connector 40, a slit 16B is provided at the rear surface of the connector housing 11B near the bottom surface. The slit 16B is also extended to both the side surfaces of the housing 11 as grooves 16B-1 and 16B-2. Ribs 17a, 17b, 18a, and 18b of the first embodiment are not provided. In this embodiment, the printed circuit board 15 is provided with the U-shaped cutout with the width X 1  which is smaller than the width W of the housing 11. Thus, the printed circuit board 15 is connected to the connector 40 in a manner that the portions of the side edges 15e and 15f are held within the grooves 16B-1 and 16B-2, respectively. The depth of the grooves 16B-1 and 16B-2 are determined by the width W of the housing 11 and the width W 1  shown in FIG. 13, in which W 1  is slightly larger than X 1  to allow the accommodation of the printed circuit board 15 to the housing 11. The housing 11B is provided with contact pins 12C. 
     FIGS. 16 through 21 show a connector 50 which is the fourth embodiment of the present invention. This connector 50 is designed to accept the insertion of a flexible printed circuit sheet (FPC) 51. 
     A movable member 52 engages a space 53 which is provided to the rear surface of a housing 11C in a movable manner in the directions as shown by arrows A 1  and A 2 . The movable member 52 is provided with a slit shaped opening 54 to which the FPC 51 is inserted. As can be seen from FIG. 20, there is provided a space 55 above the movable member 52 for the purpose of accommodating the second contact part 12f. FIG. 20 also shows a sloping guiding part 56 which guides the second contact part 12f above the movable member 52. The movable member 52 is further provided with an accommodating space 57 which accepts the end of the FPC 51. The space 57 communicates to the opening 54 as well as to the space 55. 
     When the FPC 51 is to be connected to the connector 50, the movable member 52 is slightly drawn out in the direction shown by the arrow A 2  in FIG. 21. The second contact part 12f of the contact pin 12E is then guided upwardly by the sloping guiding part 56 and is disengaged from the space 57 as shown in FIG. 21. In this state, the FPC 51 is then inserted through the opening 54. This insertion is carried out without requiring a pushing force. After the insertion of the FPC 51 is achieved, the movable member 52 is pushed into the housing 11 in the direction of the arrow A 1  as shown in FIG. 20. Then, the connector 50 assumes the state shown in FIG. 20 in which the second contact part 12f is disengaged from the sloping guiding part 56 and partly projects within the space 57 from the space 55. Thus, the FPC 51 is clamped by the second contact member 12f and the electrical connection is achieved. 
     In this embodiment, the height t 1  of the space 53 is equal to the thickness t of the printed circuit board 15. Therefore, by removing the movable member 52, the connector 50 can also be connected to the printed circuit board 15 in the same way as described previously. 
     As can be seen from the drawings, the connectors 30, 40, 50, and 60 which are the second, third and fourth embodiments of the present invention, respectively, do not cause the increase of the overall thickness of the connector. Therefore, the connectors in these embodiments are also suitable for use in the telephone sets with thin configurations. The connectors 10, 30, 40, and 50 can also be employed for the connection of the cables from the telephone set to the hand set. 
     Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.