JP2005339805A - Key switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a key switch capable of preventing dust or the like from infiltrating into a key switch main body and capable of speedily and easily fitting conductive rubber in correction to a proper fitting position at assembly work of the same. <P>SOLUTION: On the key switch, having an interference evading part 'a' into which a locking part 41 is inserted at each location of the conductive rubber 21 facing the locking part 41 for fall-off prevention set at an operation button, and a printed board 1; retaining a descending stroke of the operation button; and enabled to make an interval between a printed board 1 and a panel 3 smaller; the interference evading part 'a' is constituted of a concave part 25 integrally formed with the conductive rubber 2 and an insertion hole 13 formed at the printed board 1 for the concave part 25 to be insertion fitted, and further, the concave part 25 integrally formed with the conductive rubber 2 is provided with a protrusion 26 protruded downward from the insertion hole 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a key switch, and more particularly, to a key switch capable of reducing the size between a printed circuit board and a panel without reducing the lowering stroke of an operation button.

  Conventionally, as this kind of key switch, one configured as shown in FIG. (For example, see Patent Document 1)

  3A includes a conductive rubber 2 and a panel 3 provided on a printed circuit board 1, and an operation button 4 is vertically fitted in a hole 31 opened in the panel 3. The fixed contact 11 provided to 1 and the movable contact 21 provided on the conductive rubber 2 are brought into contact with each other to be short-circuited, and an electric signal is output.

  The operation button 4 of this key switch is formed with a locking part 41 for retaining coming into contact with the lower surface of the panel 3 protruding at the corner of the lower end, etc., and the locking part 41 comes off the lower surface of the panel 3. Is configured to not.

  Further, a columnar protrusion 42 is formed on the lower surface of the operation button 4 so as to protrude from the upper surface of the convex base 22 formed integrally with the conductive rubber 2. The protrusion 42 is constantly urged upward by the elasticity of the elastic portion 23 having a skirt shape (conical shape) integrally formed on the outer periphery of the base portion 22 formed on the conductive rubber 2.

  When the operation button 4 is pushed down against the elastic force of the elastic portion 23, the protrusion 42 presses the base portion 22, and the skirt-like elastic portion 23 provided on the outer periphery of the base portion 22 is buckled. The movable contact 21 formed on 22 contacts the fixed contact 11 of the printed circuit board 1 and is short-circuited.

  Further, the key switch shown in FIG. 3A is operated by depressing the operation button 4 on each part of the conductive rubber 2 and the printed circuit board 1 facing the retaining portion 41 for preventing the removal provided on the operation button 4. In this case, the escape hole 24 and the escape hole 12 into which the locking part 41 is inserted are formed, and the interference avoiding part a in which the conductive rubber 2 and the printed circuit board 1 are in communication with each other is formed.

  Thus, by providing the escape hole 24 and the escape hole 12 in the conductive rubber 2 and the printed circuit board 1 to form the interference avoiding part a, when the operation button 4 is pushed down, the locking part 41 is in a communication state. Can be lowered without being interfered with the conductive rubber 2 and the printed circuit board 1 at all. As a result, it is possible to ensure a descending stroke of the operation button 4, to reduce the dimension between the upper surface of the printed circuit board 1 and the upper surface of the panel 3, and to reduce the thickness of the key switch. .

  However, since the key switch shown in FIG. 3A described above forms the interference avoiding portion a including the escape hole 12 and the escape hole 24 in the open state in the printed circuit board 1 and the conductive rubber 2, There is a problem that dust or the like may enter the key switch body through the escape hole 12 and the escape hole 24.

  Therefore, in order to solve this problem, in the conventional key switch, as shown in FIG. 3B, a concave portion 25 formed integrally with the conductive rubber 2, and the concave portion 25 are inserted and fitted. The interference avoiding part a is constituted by the insertion hole 13 formed in the printed circuit board 1 to be combined, and the lowering part 25 formed in the bag shape secures a downward stroke of the locking part 41 and closes the insertion hole 13. It was configured to prevent dust and the like from entering the key switch body.

Japanese Patent Laid-Open No. 5-19921 (page 2-4, FIG. 5)

  However, in the key switch shown in FIG. 3B described above, the concave portion 25 formed integrally with the conductive rubber 2 is provided on the printed circuit board 1 when the printed circuit board 1 is attached to the panel 3 during assembly work. A state in which the edge portion of the insertion hole 13 is touched and the concave portion 25 is detached from the insertion hole 13 without being fitted, and the conductive rubber 2 is entrained, or the concave portion 25 is caught in the edge portion of the insertion hole 13. As a result, there is a problem that causes the operation button 4 to malfunction. Even if such a problem occurs, the concave portion 25 does not have a portion that can be grasped and pulled, so the concave portion 25 is corrected to the proper mounting position. There was a problem that it was not easy to install and it took time to correct it.

  The present invention has been made in view of the above-described problems of the conventional key switch described above. The object of the present invention is to ensure a downward stroke of the operation button and to remove dust or the like into the key switch body. It is an object of the present invention to provide a key switch that can prevent a recess from entering, and can quickly and easily modify and attach a concave portion provided in a conductive rubber to a proper mounting position when the key switch is assembled.

In order to achieve the above object, in the key switch of the present invention, the operation button is pushed down so that the movable contact of the conductive rubber is brought into contact with the fixed contact of the printed circuit board and short-circuited, and the disconnection provided on the operation button is provided. Interference avoiding parts where the locking parts are inserted are formed at each part of the conductive rubber and printed circuit board facing the locking parts for locking, and between the printed circuit board and the panel without reducing the lowering stroke of the operation buttons. In the key switch that made it possible to reduce the size of
The interference avoidance portion is composed of a concave portion formed integrally with the conductive rubber and an insertion hole formed in the printed circuit board into which the concave portion is inserted and fitted, and a concave portion formed integrally with the conductive rubber. A protrusion that protrudes downward from the insertion hole is provided.

  Moreover, it is preferable that the protrusion provided in the concave portion is formed integrally with the concave portion.

  Furthermore, it is effective to form the protrusion provided on the concave portion in a tongue shape that can be gripped.

  The key switch of the present invention can secure a lowering stroke of the operation button and can prevent dust and the like from entering the key switch body, and also has a concave shape provided in the conductive rubber when the key switch is assembled. The part can be quickly and easily corrected and attached to the regular attachment position.

Each of the parts of the printed circuit board and the conductive rubber that is configured to short-circuit the movable contact point of the conductive rubber by contacting the fixed contact point of the printed circuit board by pressing down the operation button. In the key switch that forms an interference avoiding portion into which the locking portion is inserted, and can be configured to reduce the size between the printed circuit board and the panel without reducing the descending stroke of the operation button.
The interference avoidance portion is composed of a concave portion formed integrally with the conductive rubber and an insertion hole formed in the printed circuit board into which the concave portion is inserted and fitted, and a concave portion formed integrally with the conductive rubber. Protrusions projecting downward from the insertion holes are provided.

  A first embodiment of a key switch according to the present invention will be described with reference to FIGS. FIG. 1A is a cross-sectional view showing a configuration of a key switch, and FIG. 1B is a cross-sectional view of a main configuration showing a state where an operation button of the key switch is pushed down. In addition, the same code | symbol is attached | subjected to the part same as the prior art example shown in above-mentioned FIG. The same applies to other embodiments described below.

  In the first embodiment shown in FIGS. 1 (a) and 1 (b), a concave portion 25 is integrally formed at a portion of the conductive rubber 2 facing the retaining portion 41 for retaining the stopper provided on the operation button 4. At the same time, the concave portion 25 is inserted and fitted into the insertion hole 13 formed in the printed circuit board 1 to form the interference avoiding portion a.

  Therefore, when the operation button 4 is pushed down, the locking portion 41 is lowered as shown in FIG. 1B and inserted into the bag-like portion of the concave portion 25 forming the interference avoiding portion a. As a result, the locking portion 41 can be lowered without being interfered with the conductive rubber 2 and the printed circuit board 1 at all, so that the panel 3 can be removed from the upper surface of the printed circuit board 1 without reducing the lowering stroke of the operation button 4. Therefore, the key switch can be made thin. Further, since the insertion hole 13 can be closed by the concave portion 25, it is possible to prevent dust and the like from entering the key switch body through the insertion hole 13.

  Further, in the first embodiment, a protrusion 26 formed so as to protrude downward from the peripheral edge 131 of the insertion hole 13 is provided on the bottom surface portion of the concave portion 25 formed in the conductive rubber 2.

  In this way, by providing the protrusion 26 on the concave portion 25, it becomes possible to grasp and pull the protrusion 26 with a tool such as a finger or pliers during the key switch assembling work. It can be quickly and easily corrected and attached to the attachment position, and the protrusion 26 protrudes downward from the insertion hole 13 so that the conductive rubber 2 placed on the printed circuit board 1 can be fixed more reliably. The lateral displacement of the conductive rubber 2 can be prevented.

  Next, two embodiments of the key switch according to the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of the key switch.

  The second embodiment shown in FIG. 2 is characterized in that the concave portion 25 and the protrusion 26 are formed integrally and formed into a tongue shape that can be gripped by a tool such as a finger or pliers.

  As in the second embodiment, the protrusion 26 is formed integrally with the concave portion 25 and can be gripped, so that the insertion portion formed in the printed board 1 by the concave portion 25 when the key switch is assembled. Since the tongue-shaped protrusion 26 can be grasped and pulled with a tool such as a finger or pliers even when it is caught on the edge portion 13, it can be quickly and easily corrected and attached to a regular attachment position. At the same time, the protrusion 26 protrudes downward from the insertion hole 13, whereby the conductive rubber 2 placed on the printed circuit board 1 can be more securely fixed, and the lateral displacement of the conductive rubber 2 is prevented. be able to.

It is sectional drawing which shows the structure of the 1st Example of this invention. It is sectional drawing which shows the structure of the 2nd Example of this invention. It is sectional drawing which shows the structure of the conventional key switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 11 Fixed contact 12 Escape hole 13 Insertion hole 131 Perimeter edge 2 Conductive rubber 21 Movable contact 22 Base 23 Elastic part 24 Escape hole 25 Concave part 26 Protrusion 3 Panel 31 hole 4 Operation button 41 Locking part 42 Protrusion part a Interference avoidance unit

Claims (3)

While the operation button is pressed down, the movable contact point of the conductive rubber is brought into contact with the fixed contact point of the printed circuit board and short-circuited.
Interference avoiding parts where the locking parts are inserted are formed on the conductive rubber and the printed circuit board facing the locking parts provided on the operation buttons to oppose the printed parts without reducing the stroke of the operation buttons. In the key switch that made it possible to reduce the size between the board and the panel,
The interference avoidance portion is composed of a concave portion formed integrally with the conductive rubber and an insertion hole formed in the printed circuit board into which the concave portion is inserted and fitted, and a concave portion formed integrally with the conductive rubber. A key switch comprising a protrusion protruding downward from the insertion hole.   The key switch according to claim 1, wherein the protrusion provided on the concave portion is formed integrally with the concave portion.   3. The key switch according to claim 1, wherein the protrusion provided on the concave portion is formed in a tongue shape that can be gripped.

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