JPH058835U - Push button switch - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a push button switch capable of setting a long overstroke and improving connection reliability. [Structure] A thin portion 9c for supporting the pressing portion 9a is provided around a pressing portion 9a having a pressing protrusion 8 formed on a top portion 9 of a click rubber 7, and the pressing portion 9a is provided at a central portion of a lower surface of a key top 11. Stem projections 12 facing each other with a predetermined space
a is provided, and the stem projection 12a presses the pressing portion 9a at the stroke end of the key top 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a push button switch which is used as a key switch of a keyboard device and in which a switch element such as a membrane switch is pressed and driven through a click rubber.

[0002]

[Prior Art]

 FIG. 3 is a sectional view showing a conventional example of this type of push button switch.

In FIG. 1, a membrane switch 1 has a movable contact 3 provided on a lower surface of a flexible upper sheet 2 and a fixed contact 5 provided on an upper surface of a lower sheet 4, and both sheets 2 and The spacers 6 are provided between the four, and the click rubber 7 placed on the membrane switch 1 has a skirt-shaped side wall portion 10 extending around a top portion 9 having a pressing protrusion 8. However, the side wall portion 10 is configured to generate a click feeling when buckling. The key top 11 placed on the top 9 of the click rubber 7 is provided with a stem 12 projecting downward so that the stem 12 can move up and down in the guide hole 13a of the housing 13. There is. The membrane switch 1 is mounted on a support plate 14 such as a metal plate, and the support plate 14 supports the click rubber 7 and the housing 13.

In the push button switch configured as described above, when the operator pushes the key top 11 and lowers the top 9 of the click rubber 7 by a predetermined amount, the side wall 10 buckles and the key top 11 moves the top. Since the reaction force received from 9 suddenly decreases, the click feeling is transmitted to the operator's finger. Then, the buckling of the side wall portion 10 pushes the top portion 9 vigorously, so that the pushing protrusion 8 of the click rubber 7 collides with the upper sheet 2 of the membrane switch 1 and pushes it in, and as a result, the movable contact 3 is fixed. The switch is switched from off to on by touching. Even after the on-timing at which the movable contact 3 comes into contact with the fixed contact 5, the key top 11 is slightly lowered because the pressing protrusion 8 is slightly compressed by the pressing operation force, and this lowering amount causes an overstroke. Becomes

Further, when the pressing operation force on the key top 11 is removed in such an ON state, the click rubber 7 returns to the original substantially truncated cone shape by its elasticity, so that the key top 11 is pushed up to the initial position. The upper sheet 2 that has been bent downward is restored, the contacts 3 and 5 are separated, and the state returns to the off state.

[0006]

[Problems to be solved by the device]

 However, in the above-described conventional push button switch, the stroke end is reached immediately after the on-timing at which the movable contact 3 contacts the fixed contact 5, that is, since the overstroke is small, it is difficult to say that the operation feeling is good. Also, there was a problem that the on-timing variation was clearly perceived by the operator.

[0007] Therefore, an object of the present invention is to solve the problems of the prior art, and to provide a push button switch that can set a long overstroke and has high connection reliability.

[0008]

[Means for Solving the Problems]

 The object of the present invention described above is to extend a skirt-shaped side wall portion around a key top that is held up and down and a top portion that has a pressing protrusion, and the side wall portion causes a click feeling when buckling. It is provided with rubber and a switch element in which a movable contact driven to be pressed by the pressing protrusion is opposed to a fixed contact, and when the key top is pushed to buckle the side wall of the click rubber, the side wall of the click rubber is pushed through the pressing protrusion. In a push button switch that performs switching, a thin portion that supports the pressing portion is provided around the pressing portion where the pressing protrusion is formed on the top of the click rubber, and the pressing portion is provided on the lower surface of the key top. This is achieved by providing a stem protrusion that faces the above-mentioned part at a predetermined distance, and the stem protrusion presses the pressing part at the stroke end of the key top. It is.

[0009]

[Action]

 According to the above means, the pressing protrusion provided on the pressing portion of the click rubber drives the movable contact of the switch element to regulate the downward movement of the pressing portion, and then the thin portion around the pressing portion is bent by the pressing operation force. Therefore, the key top can be further lowered by a predetermined amount, and the overstroke becomes longer. In addition, since the system protrusion directly presses the pressing portion of the click rubber immediately before reaching the stroke end, the contact pressure between both contacts can be increased and reliability is improved.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a push button switch according to an embodiment of the present invention in an off state, and FIG. 2 is a sectional view of the push button switch in an on state, showing a portion corresponding to FIG. 3 described above. Are given the same reference numerals.

In the push button switch shown in FIGS. 1 and 2, the top portion 9 of the click rubber 7 is supported by a pressing portion 9 a having a bottomed cylindrical shape and a pressing protrusion 8 protruding from the bottom surface, and a skirt-shaped side wall portion 10. At the same time, it is composed of an annular receiving portion 9b to which a pressing operation force is applied from the stem 12 and a thin wall portion 9c formed around the pressing portion 9a in the form of a collar and supported by the receiving portion 9b. Thus, the pressing portion 9a is held below the receiving portion 9b. In addition, a stem protrusion 12a is formed in the center of the lower surface of the stem 12, and the stem protrusion 12a faces the upper surface of the pressing portion 9a with a predetermined distance.

Therefore, when the operator pushes in the key top 11 and the peripheral portion of the lower surface of the stem 12 integrated with the key top 11 lowers the receiving portion 9b of the top portion 9 of the click rubber 7 by a certain amount, the side wall portion is formed. The buckling of 10 causes a click feeling, and the buckling of the side wall 10 causes the pressing portion 9a to move down vigorously, so that the pressing projection 8 collides with the upper sheet 2 of the membrane switch 1 and pushes it in. As a result, the movable contact 3 comes into contact with the fixed contact 5 to perform switching from OFF to ON. When the movable contact 3 comes into contact with the fixed contact 5, the pressing portion 9a of the top portion 9 of the click rubber 7 is restricted from descending, but the pressing portion 9a is continuously pressed by the pressing operation force. Since the thin portion 9c around the part bends, the receiving portion 9b further descends, and when the connecting portion of the receiving portion 9b and the thin portion 9c comes into contact with the membrane switch 1 as shown in FIG. At this time, the stem 12 directly applies a pressing operation force not only to the receiving portion 9b but also to the pressing portion 9a so that the pressing portion 9a can be slightly compressed.

As described above, in the above-described embodiment, after the movable contact 3 comes into contact with the fixed contact 5 and the downward movement of the pressing portion 9a of the click rubber 7 is restricted, the thin portion 9c provided around the pressing portion 9a is prevented. Since the key top 11 can be pushed further by a predetermined amount by utilizing the bending, the overstroke can be set longer by that amount, and the push button switch has a good operation feeling. Further, when the overstroke is long, there is an advantage that even if there is some variation in the on-timing, it is difficult for the operator to perceive it.

Further, in the above embodiment, the stem protrusion 12a of the stem 12 directly presses the pressing portion 9a of the click rubber 7 immediately before reaching the stroke end, so that the contact point between the contacts 3 and 5 is It also has the advantage of increased pressure and improved connection reliability.

The configuration and operation of the parts of the above-described embodiment not particularly described are the same as those of the conventional example.

[0017]

[Effect of the device]

 As described above, according to the present invention, it is possible to further lower the key top by a predetermined amount by utilizing the bending of the thin portion after the on-timing, and the overstroke is lengthened accordingly, which leads to good operation. It has the excellent effect that it is not only perceived by the operator but also that there is some variation in the on-timing, and this push-button switch can be realized simply by changing the shape of the top of the click rubber. There is no need to worry about cost increase. Further, since the stem projection of the key top directly presses the pressing portion immediately before reaching the stroke end, the contact pressure between the movable contact point and the fixed contact point increases, and the connection reliability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a push button switch in an off state according to an embodiment of the present invention.

FIG. 2 is a sectional view of the push button switch shown in FIG. 1 in an ON state.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Membrane Switch (Switch Element) 3 Moving Contact 5 Fixed Contact 7 Click Rubber 8 Pressing Protrusion 9 Top 9a Pressing 9b Receiving 9c Thin Wall 10 Sidewall 11 Key Top 12 Stem 12a Stem Protrusion

Claims (1)

[Claims for utility model registration] [Claim 1] A skirt-shaped side wall portion is extended around a key top that is held so as to be able to move up and down and a top portion that has a pressing protrusion, and the side wall portion has a click feeling when buckling. And a switch element in which a movable contact driven to be pressed by the pressing protrusion is opposed to a fixed contact, and the key top is pushed to buckle the side wall portion of the click rubber to press the In a push button switch that is switched through a protrusion, a thin portion that supports the pressing portion is provided around the pressing portion where the pressing protrusion is formed on the top portion of the click rubber, and the lower surface of the key top is provided with the thin portion. Providing a stem protrusion that faces the pressing part at a predetermined interval,
A push button switch characterized in that the stem projection is configured to press the pressing portion at the stroke end of the key top.