JPH0350370B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch in which a conductive movable contact piece for making electrical contact between terminals has a high contact pressure.

Conventionally, there are several types of electrical contact mechanisms between terminals in switches, but regardless of the type, there are problems with the contact between the contact part of the conductor movable contact piece and the contact part of the terminal (hereinafter referred to as the bridge part). It was hot. For example, in the switch shown in FIG. 1, one end 4 of the contact piece 3 fixed to the bridge portion 2a of the terminal 1a is pressed from above to bring the contact portion 5 into contact with the bridge portion 2b of the terminal 1b. 5, and since it is simply pressed, dust and flux cannot be removed effectively. Furthermore, it is necessary to apply chemically stable noble metal plating because it cannot deal with the oxide film that forms over time. In the switch shown in FIG. 2, the contact piece 7, which is pressed downward by the biasing means 6, is moved to the right to bring the contact portion 8a of the contact piece 7 into contact with the bridge portion 10a of the terminal 9a. The contact part 8b is brought into contact with the bridge part 10b of the terminal 9b while maintaining the contact part 8b, but since the contact part 8b and the bridge part 10b are rubbed, it is better than simply pressing, but it is not enough to remove the deposits sufficiently. There is a structural limit to applying this contact pressure. Further, a switch is known in which a movable contact piece is pressed by a push button and comes into contact with a fixed terminal (Japanese Utility Model Publication No. 10017/1983). However, even with this switch, since the contact end of the movable contact piece contacts the fixed terminal in surface or line contact, it is not possible to apply enough contact pressure to sufficiently remove conduction obstructions such as flux, dust, and oxide film. There is a drawback.

The present invention was made in view of the above-mentioned difficulties, and its features include opposing terminals each having a bridge portion, and a contact end formed by cutting one end at an acute angle and bending the other end to one end of the terminal. A contact piece consisting of a conductive elastic plate is placed opposite to the bridge part of the terminal, and the other end is fixed to the bridge part of the other terminal. a pressing member for contacting the pressing member, a driving member that pushes the pressing member downward, and a holding plate that is located between the contact piece and the driving member and has a hole at a position corresponding to the pressed portion of the contact piece. The contact end is brought into contact with the bridge part of one terminal by pressing the pressing member through the holding plate, and the contact end is brought into contact by pressing the midway of the contact piece downward. The acute-angled apex of the end moves while contacting the bridge portion, thereby causing the bridge portion to scratch and come into contact.

The present invention will be explained below using a rotary switch for binary setting of an electronic circuit as an example.

FIG. 3 is an assembled view of the rotary switch according to the present invention, and FIG. 4 is a sectional view of the rotary switch. Housing 1 indicated by the dotted line in Figure 3
1, four output terminals 12a to 12d and one common input terminal 13 are arranged by insert molding, and the bridge part 14 of the input terminal 13 is provided with a contact made of a conductive elastic metal plate. 15 is fixed by welding or the like. The contactor 15 is divided into four movable contact pieces 16a to 16d from the fixed part to the input terminal bridge part 14. Contact piece 16a
~16d are bent at the base and urged upward, and the tips 17a~17d are the seventh
As shown in the figure, the bridge portions 18a-1 of the terminals 12a-12d are formed by cutting to form an acute angle 17e, and are bent downward as shown in FIG. 6a.
They are arranged opposite to each other at 8d. Contact pieces 16a-16
d, the acute-angled apexes P of the contact ends 17a to 17d make point contact with the bridge portions 18a to 18d, making it possible to apply high contact pressure.

Note that the contact pieces 16a to 16d are not formed on the contactor 15, and the contact pieces 16a to 16d are formed on the input terminal bridge portion 14.
It may be fixed to the output terminal bridge portion 14, or may be integrally molded with these terminals.

Steel balls 20a to 20d are placed on the contact pieces 16a to 16d as pressing members for pressing the contact pieces 16a to 16d.
are held and disposed in the holes 22a to 22d of the holding plate 21. The retaining plate 21 includes an inner wall of the housing 11, a protruding piece 23 and a contact piece 16b provided diagonally.
The contact pieces 16a to 16 are supported by a projecting piece 24 (FIG. 4) provided between the contact piece 16c and the contact pieces 16a to 16 are fixed from above and urged upward.
d elastically restrains the contact end 17a at the tip of the contact piece.
17d are located at an appropriate height from the bridge portions 18a to 18d. The holes 22a to 22d of the holding plate 21 are formed to be located halfway between the contact pieces 16a to 16d, respectively, and the steel balls 20a to 20d
larger than the diameter of Therefore, the steel balls 20a to 20d
The contact pieces 16a to 16a are movable in the vertical direction through the holes 22a to 22d, and contact the lower surface of the holding plate 21.
16d, and a portion is exposed above the holding plate 21. When pressed from above, the steel balls 20a to 20d move to the contact piece 16.
a to 16d downward and contact ends 17a to 17
The apex P of the acute angle d is brought into contact with the bridge portions 18a to 18d (Fig. 6a), and the apex P is moved by further bending the contact pieces 16a to 16d, thereby scratching the bridge portions 18a to 18d. (Figure 6b). In this way, the contact ends are not only brought into point contact, but also scratched while maintaining a high contact state, so not only dust and flux but also oxide films are easily removed, and the activated contact surfaces of the terminal bridges are easily removed. Contact.

Although a steel ball is used as a member for pressing the contact piece, any material that can smoothly engage with the driving member described below and push down the contact piece and bend it downward may be used. , a rod with a rounded head, etc. are used. Further, the pressing member may be provided on the contact piece itself, and in that case, the contact piece may have a shape having a smooth protrusion, such as a substantially circular shape.

The steel balls 20a to 20d are selectively pressed by a rotary drive plate 25, which is a drive member. Drive plate 25
According to the numerical weighting given to the output terminals 12a to 12d, the back surface of
A convex portion 27 protruding from 6 is formed. Side 2
Since the steel ball 20 located at 6 (FIG. 4) is not pressed, the contact piece 16 disposed below does not come into contact with the output terminal bridge portion 18, and the output terminal 12 does not output. Since the ball 20 located on the convex portion 27 is pressed, the contact piece 16 comes into contact with the output terminal bridge portion 18, and the input terminal 1
3 and output. Driving plate 25 with arrow 28
By rotating clockwise as shown, terminal 12
A to 12d are selectively output, and a numerical value is output in binary depending on the combination of the output terminals.

The positioning ring 3 is inserted into the corrugated groove 29 of the drive plate 25.
The switch is assembled by engaging the recess 31 of the housing 10, placing the housing 32 on top, and fitting the protrusion 34 of the housing 10 into the hole 33.

Although the above description has been made using a rotary switch for binary setting as an example, the present invention is not limited to this. As shown in FIG.
7, or a push button switch in which a pressing protrusion 38 serving as a pressing member is provided on the contact piece 39 itself as shown in FIG.

As is clear from the above embodiments, the switch of the present invention has opposing terminals each having a bridge portion, and a contact end formed by bending one end formed at an acute angle by cutting, to one terminal of the terminal. A contact piece consisting of a conductive elastic plate is placed facing the bridge part of the other terminal and the other end is fixed to the bridge part of the other terminal, and one end is brought into contact with the bridge part of one terminal by pressing the middle part of the contact piece downward. It consists of a pressing member for pressing the pressing member downward, a driving member that presses down the pressing member, and a holding plate that is located between the contact piece and the driving member and has a hole at a position corresponding to the middle of the contact piece, and the contact end is As the middle part of the contact piece is pressed by the pressing member through the holding plate, the acute-angled vertex comes into contact with the bridge part of one terminal, so the contact piece is pushed down and deflected, causing the contact piece to contact the bridge part. Since the edge is subjected to high contact pressure and scratches the bridge, it destroys not only flux and dust but also the oxide film and exposes the active surface, which comes into contact with the bridge. As a result, stable and reliable switching can be achieved, and it can also be applied to extremely small current switching. Furthermore, there is no need for plating with gold or silver, and the structure is simple, making the switch significantly cheaper.

[Brief explanation of drawings]

Figures 1 and 2 are conceptual diagrams of a conventional switch, Figures 3 and 4 are assembled diagrams and cross-sectional views of a rotary switch showing an embodiment of the present invention, and Figure 5a.
6-c are conceptual diagrams showing other embodiments of the present invention, FIGS. 6a and 6b are explanatory views of the operation of the switch of the present invention, and FIG. 7 is a perspective view of the movable contact piece in the manufacturing process. 14, 18... Bridge section, 12, 13... Terminal, 1
7e...Acute angle, 17, 17a-17d...Contact end, 16, 16a-16d...Movable contact piece, 20
...Press member, 20a-20d...Steel ball, 25...
...Drive member, P...Acute angle apex, 22a to 22d
... Hole, 21 ... Holding plate.

Claims (1)

[Claims] 1. Opposing terminals 12 and 13 having bridge portions 14 and 18, respectively, and a contact end 17 formed by cutting one end into an acute angle 17e and bending the other end are arranged opposite to the bridge portion of one of the terminals. , a contact piece 1 consisting of a conductor elastic plate whose other end is fixed to the bridge portion of the other terminal.
6, a pressing member 20 for pressing the middle part of the contact piece downward to bring the one end into contact with the bridge portion of the one terminal, a driving member 25 for pressing down the pressing member downward, and the contact piece. A holding plate 21 is provided between the piece 16 and the driving member 25 and has a hole 22 at a position corresponding to the middle of the contact piece. A switch characterized in that the acute-angled apex P moves while contacting the bridge portion of the one terminal when the middle of the piece is pressed, thereby scratching the bridge portion and bringing it into contact.