JPH069401Y2 - Push button device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Use The present invention relates to a push button device.

(B) Conventional Technology Conventionally, pushbutton devices having a structure as shown in FIGS. 5 and 6 are known.

That is, a rubber sheet (C) in which a movable contact (conductive rubber) (B) is provided at a position facing the fixed contacts on a printed circuit board (A) on which a plurality of fixed contacts are patterned.
Is mounted and a push button (F) is arranged between the pressing portion (D) corresponding to the movable contact (B) of the rubber sheet (C) and the cabinet (E).

When the operation portion (H) of the push button (F) exposed through the through hole (G) formed in the cabinet (E) is pressed, the push piece (I) of the push button (F) is pushed according to the operation. The pressing portion (D) of the rubber sheet (C) is pressed.

When the pressing portion (D) is thus pressed, the thin portion (J) of the rubber sheet (C) is bent and deformed, and the movable contact (B) moves downward. Therefore, the movable contact (B) and the fixed contact of the printed circuit board (A) come into contact with each other to close the switch circuit.

(C) Problems to be Solved by the Invention According to the above-mentioned conventional technology, a mechanical switch (for example,
Since it is not necessary to dispose a tact switch or the like), it is possible to make the device thinner.

However, in the above conventional technique, various problems occur when the distance between the printed circuit board and the cabinet changes.

That is, as the distance between the printed circuit board and the cabinet increases, the stroke of the push button for closing the switch increases, so that the push button pressed as shown in, for example, FIG. 6 is combined with the elastic deformation of the rubber sheet. There is a risk that it will get caught in the back of the cabinet and get caught.

To solve such a problem, the length of the push piece of the push button may be increased according to the distance between the printed circuit board and the cabinet, but such a push button can be used only in a specific model, and there is a problem in versatility. Cause

Further, when the cabinet is inclined with respect to the printed circuit board, it is necessary to use a plurality of sets of push buttons having different shapes in the same set, which causes problems in parts management and assembly workability.

(D) Means for Solving the Problems In view of the above problems, the present invention provides a plurality of fixed contacts patterned on a printed circuit board, a rubber sheet placed on the printed circuit board, and a back surface of the rubber sheet. And a plurality of movable contacts provided at positions facing each of the fixed contacts, a push button having a pressing piece that presses the operating portion exposed from the cabinet and the pressing portion of the rubber sheet corresponding to each movable contact, A rib having an abutting surface provided on the periphery of each of the pressing parts and abutting the flange part of the push button, wherein the rib has a substantially uniform distance between the abutting surface and the cabinet. The present invention provides a push button device that does.

(E) Action According to the present invention, when the operation portion of the push button is pressed, the pressing piece of the push button presses the pressing portion of the rubber sheet, so that the movable contact moves downward and comes into contact with the fixed contact of the printed circuit board. . At this time, the flange portion of the push button contacts the rib.

Further, by making the height of the rib different according to the distance between the printed circuit board and the cabinet, a constant pressing stroke can be achieved.

(F) Embodiment FIG. 1 is a perspective view showing a telephone to which a push button device according to the present invention is applied. (1) is a telephone body cabinet, and (2) is a key operation part.

2 and 3 are views showing an embodiment of the present invention. (3)
Is a printed circuit board on which fixed contacts are patterned, (4) is a rubber sheet placed on the printed circuit board (3), and (5) is provided on the back surface of the rubber sheet (4) and at a position facing the fixed contacts. Movable contact made of conductive rubber, (6) is an operating part (6a) exposed from the cabinet (1) and the movable contact (5)
A push button having a pressing piece (6b) for pressing the pressing portion (7) of the rubber sheet (4) corresponding to the above, and (8) is provided on the periphery of the pressing portion (7) and has a flange portion (6c) of the push button (6). Is a rib that abuts. Although only a single device is shown in FIGS. 2 and 3, it can be said that the same configuration is provided for each button constituting the key input unit (2) in FIG. Needless to say, for example, the rubber sheet (4) is constructed as shown in FIG.

Such a push button device has a rubber sheet (4) on the printed circuit board (3).
Is positioned and placed by a separately provided positioning means so that the fixed contact and the movable contact face each other, and the push button (6) is arranged between the rubber sheet (4) and the cabinet (1). It can be assembled.

In such an assembled state, the operation portion (6a) of the push button (6) is exposed from the through hole (1a) formed in the cabinet (1), and the flange portion (6c) of the push button (6) is exposed in the cabinet (1).
Located on the back side of.

When the operation portion (6a) of the push button (6) exposed through the through hole (1a) formed in the cabinet (1) is pressed, the pressing piece (6b) of the push button (6) is pressed according to the operation. ) Presses the pressing portion (7) of the rubber sheet (4).

When the pressing portion (7) is thus pressed, the thin portion (9) of the rubber sheet (4) is bent and deformed, and the movable contact (5) moves downward. Therefore, the movable contact (5) comes into contact with the fixed contact of the printed circuit board (3), and the switch circuit is closed.

Further, when the push button (6) moves by a predetermined stroke due to the pressing operation of the operation portion (6a) of the push button (6), the flange portion (6c) of the push button (6) and the rib (8) come into contact with each other, and Push button (6)
Restrain the movement of. Therefore, the push button (6) is attached to the cabinet (1).
It goes around to the back side and is prevented from getting caught.

When the cabinet (1) is inclined with respect to the printed circuit board (3) as shown in FIGS. 2 and 3, the height of the rib (8) gradually increases as shown in FIG. The rubber sheet (4) 'thus formed is used.

If such a rubber sheet (4) 'is used, the pressing stroke of the push button (6) becomes constant regardless of the distance between the printed board (3) and the cabinet (1). In this case, rubber sheet
It is preferable that the pressing portion (7) of (4) ′ is constructed so that the height thereof is also gradually increased.

In this way, push buttons having the same shape can be used regardless of the distance between the printed circuit board (3) and the cabinet (1).

(G) Effect of the Invention According to the present invention, a rib is provided on the rubber sheet and the pressing stroke of the push button is restricted by the rib, so that the push button does not go around the back side of the cabinet and get caught. .

Further, if the height of the rib is made different according to the distance between the printed circuit board and the cabinet, and the distance between the contact surface of the rib with the flange portion and the cabinet is substantially uniform, for example, the cabinet can be mounted on the printed circuit board. Even when the push buttons are inclined, the pressing strokes of all the push buttons can be made uniform, and since push buttons having the same shape can be used, it is possible to improve parts management and workability.

[Brief description of drawings]

FIG. 1 is a view showing a telephone to which a push button device according to the present invention is applied, FIGS. 2 and 3 are sectional views showing an embodiment of the present invention, and FIG. 2 is a view showing a state before operation. FIG. 3 is a diagram showing a state after operation, FIG. 4 is a diagram showing an example of a rubber sheet, FIG. 5 is a cross-sectional view showing a conventional example, and FIG. 6 is a diagram used for explaining a conventional technique. is there. (1) ... Cabinet, (3) ... Printed circuit board, (4) ... Rubber sheet, (5) ... Movable contact, (6) ... Push button, (6a) ... Operation part, (6b) ... Pressing piece, (6c) … Flange, (7)…
Pressing part, (8) ... rib.

Claims (1)

[Scope of utility model registration request] 1. A plurality of fixed contacts patterned on a printed circuit board, a rubber sheet mounted on the printed circuit board, and a rear surface of the rubber sheet, which is provided at a position facing each of the fixed contacts. A plurality of movable contacts, a push button each having an operating portion exposed from the cabinet and a pressing piece for pressing the pressing portion of the rubber sheet corresponding to each movable contact, and a flange of the push button provided on the periphery of each pressing portion. A push button device, comprising: a rib having an abutting surface with which the portion abuts, the rib having a substantially uniform distance between the abutting surface and the cabinet.