BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a perspective view of a press-fit contact according to a first embodiment of the present invention;
FIG. 1B shows a front view of press-fit contacts according to the first embodiment, which are arranged in a line;
FIG. 1C shows a sectional view along a line 1C-1C in FIG. 1B;
FIG. 2A shows a perspective view of a press-fit contact according to a second embodiment of the present invention;
FIG. 2B shows a front view of press-fit contacts according to the second embodiment, which are arranged in a line;
FIGS. 3A to 3C respectively show sectional views along lines 3A-3A, 3B-3B, and 3C-3C in FIG. 2B;
FIG. 4 shows an illustration of arrangement of press-fit contacts according to the present invention for sections of expanded-portions of press-fit portions;
FIG. 5 shows a sectional view for a method of mounting press-fit contacts according to the present invention into through-holes of a printed circuit board with use of a jig;
FIG. 6 shows a perspective view for the mounting method of the press-fit contacts;
FIG. 7A shows a perspective view of a conventional press-fit contact;
FIG. 7B shows a front view of conventional press-fit contacts arranged in a line;
FIG. 7C shows a sectional view along a line 7C-7C in FIG. 7B; and
FIG. 8 shows a perspective view of the press-fit contact mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A detailed description will now be given of preferred embodiments of the present invention, with reference to the accompanying drawings.
FIGS. 1A to 1C show a press-fit contact 1 according to a first embodiment of the present invention, which includes a steeple like introduction portion 1a for introducing the contact 1 into the through-hole 11a (see FIGS. 7 and 8) of the printed circuit board, a press-fit portion 1c adapted to have expanded portions 1b, 1b projecting along both sides in the shape of an arc while forming an elliptical slit 1f, a bulge portion 1d extended from the press-fit portion 1c and fixed in a fixing hole of an insulating housing, and a contact portion 1e extended from the bulge portion 1d. The press-fit portion 1c is press-fitted into the through-hole 11a of the printed circuit board.
The expanded portions 1b, 1b of the press-fit portion 1c projecting in the shape of an arc are twisted around their shaft center “c” in a circumferential direction as shown in FIG. 1C. As a result, when a plurality of press-fit contacts 1 is arranged in parallel in alignment with a line “a”, the expanded portions 1b, 1b of adjacent press-fit portions 1c are arranged in parallel with each other so as to be rotated by a twist angle θ with respect to the line “a”, such that their direction of expansion “b” is not in alignment with a line. In the present embodiment, the twist angle θ is approximately 45 degrees. In addition, the bulge portion 1d is twisted so that the press-fit portion 1c is rotated together with the twisted bulge portion 1d in plane with the rotation angle θ, and the expansion directions “b” of the expanded portions 1b, 1b are thus uniform in a long direction.
FIGS. 2A and 2B show a press-fit contact 1 according to a second embodiment, where the press-fit portion 1c itself is twisted. As shown in FIG. 2B, when three horizontal cross-sections 3A, 3B, and 3C are viewed vertically from the top, the press-fit contact 1 is not yet twisted in the cross-section 3A as shown in FIG. 3A, is rotated by an angle θ1 with respect to a line “a” in the cross-section 3B as shown in 3B, and is rotated by an angle θ2 (θ2>θ1) in the cross-section 3C as shown in 3C. More specifically, the expanded portions 1b, 1b of the press-fit portion 1c are twisted around the shaft center “c” in a circumferential direction to form a spiral shape.
When the press-fit contacts 1 according to the present invention formed as described above are press-fitted into the through-holes 11a of the printed circuit board 11, as shown in FIG. 4, the arrangement of the contacts in alignment with a line a1 brings the expansion directions “b” of the expanded portions 1b, 1b parallel to each other at an angle θ with respect to the line a1. The same applies to a line a2 perpendicular to the line a1. As a result, the concentration of contact pressure due to press-fitting of the press-fit portions 1c will not be caused between adjacent through-holes 11a, 11a.
In addition, when press-fit contacts are disposed in two or more rows, there will be through-holes 11a, 11a with the expansion directions b, b . . . in alignment as shown in FIG. 4. However, the arrangement of the through-holes 11a, 11a in the oblique direction makes the distance “L” therebetween substantially longer than the vertical and horizontal arrangement, that is, the arrangement of the expansion directions in alignment with the lines a1 and a2. Thus, the contact pressure is relaxed to eliminate a possibility of generation of damage to the board.
In order to press-fit the press-fit contacts 1 according to the present invention into a printed circuit board 11, as shown in FIGS. 5 and 6, the printed circuit board 11 and an insulating housing 12 are placed on a receiving jig 3, the press-fit contacts 1 are inserted into each of a plurality of fixing holes 12a, and a driving jig 4 with escape holes 4a, with each contact portion 1e put in an escape hole 4a, is placed on the press-fit contact 1 and pressed downward, causing the introduction portions 1a of the press-fit contacts 1 to pass through the through-holes 11a so to project downwardly, and the bulge portions 1d are thus press-fitted and fixed in the fixing holes 12a with the expanded portions 1b, 1b of the press-fit portions 1c strongly contacted against the walls of the through-holes 11a.
As many apparently widely different embodiments and variations of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof and described herein, except as defined in the appended claims.
Patent Application
20080050946
