JPH0119776Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a push button switch used in keyboards of electric typewriters, word processors, etc.

In recent years, electronic devices such as electric typewriters and word processors are required to be smaller, thinner, and lighter. The keyboard of this electronic device also shows a similar tendency. For this reason, the wall thickness of the case of the push button switch used for this is becoming thinner in order to reduce the weight.

However, when the wall thickness of the case is made thinner, when a pressing force is applied from the side of the case, the case bends and the side wall of the case comes into contact with the stem of the push button, making it difficult to press the push button smoothly. There is a possibility that a problem may arise that it becomes difficult to operate.

Therefore, in this invention, the lower part of the upper case is fitted into the lower case, and a push button is held in the upper case so that it can move forward and backward toward the bottom of the lower case, and by operating the push button, the push button can be inserted into the case. In a push button switch that opens and closes a set of contacts,
A push button switch has a rib protruding from the bottom of the lower case close to the side wall, and the lower end of the upper case is fitted between the rib and the side wall, so that the upper case can be viewed from the side. This prevents the lower end of the upper case from displacing inward when pressed, reducing the inward deflection of the upper case side wall, so that the upper case side wall does not interfere with smooth operation of the push button. It is characterized by the following.

Next, this invention will be explained based on the drawings.

In FIGS. 1 to 3, 1 is a lower case of the push button switch, 2 to 5 are side walls of the lower case 1, and 6 is the bottom of the lower case 1. A projection 7 is provided protruding from the center of the bottom 6 of the lower case 1, and ribs 8, 9 are provided protruding from the peripheral edge of the bottom 6 in proximity to the side walls 2, 4. The ribs 8 and 9 extend along the side walls 2 and 4, and a case fitting groove 10 is formed between the rib 8 and the side wall 2, and a case fitting groove is formed between the rib 9 and the side wall 4. 11 is formed.

A lower portion of a thin upper case 12 is fitted into the lower case 1 (see FIG. 3). Moreover,
The lower ends of the side walls 12a, 12b of the upper case 12 are fitted into the case fitting grooves 10, 11. A hole 13 is bored in the upper wall 12c of the upper case 12, and the upper part 14 of the stem 14 is inserted into the hole 13.
a is slidably inserted. A spring 15 is interposed between the intermediate wall 14b of the stem 14 and the bottom 6 of the lower case 1.
4 is biased upward by a spring.

The stem 14 also has a recess 16 that opens upward.
is formed, and a protrusion of a push button (not shown) is fitted into this recess 16. Moreover, by pressing the push button downward against the spring force of the spring 15 and displacing the stem 14 toward the bottom 6, contacts (not shown) are opened and closed. Reference numeral 17 indicates a light emitting diode attached to the upper case 12.

Next, the operation and function of the push button switch having such a configuration will be explained.

The contacts (not shown) are opened and closed as described above. On the other hand, the side wall 12a or 12b of the upper case 12
When a pressing force is applied from the side, the force distributed to the upper end of the side wall 12a or 12b is received by the upper wall 12c, and the force distributed to the sides of the side wall 12a or 12b is received by the side walls 12d, 12e. The force that is received by the ribs 8 or 9 and distributed to the lower end of the side wall 12a is received by the ribs 8 or 9. As a result, side wall 1
Even if a pressing force is applied from the side to 2a or 12b, side wall 12a or 12b only slightly bends locally (towards the stem 14), but does not bend significantly. Therefore, the side walls 12a,
Even if 12b is bent, the side walls 12a, 12b do not bend so much as to hit the stem 14, so the vertical movement of the stem 14 during push button operation is not hindered.

As explained above, this invention is achieved by fitting the lower part of the upper case into the lower case, holding the push button in the upper case so that it can move forward and backward toward the bottom of the lower case, and operating the push button. In a push-button switch that opens and closes contacts disposed inside the case, a rib is provided protruding from the bottom of the lower case close to the side wall, and the lower end of the upper case is fitted between the rib and the side wall. Since the push button switch is designed so that the upper case is pressed from the side, the lower end of the upper case is prevented from moving inward, and the side wall of the upper case is prevented from being bent inward. Can be made smaller. As a result, even if a pressing force acts on the side wall of the upper case from the side, the side wall of the upper case can be prevented from coming into contact with the stem of the push button, so that the push button can be operated smoothly.

Further, since the side wall of the upper case does not protrude downward from the bottom wall of the lower case, the push button switch can be tightly fixed to the printed circuit board. As a result, the push button switch can be assembled to the printed circuit board in a stable manner.

Furthermore, since the bottom wall of the lower case is provided with ribs for holding the side walls of the upper case, the strength of the lower case can be improved even if the bottom wall and side walls of the lower case are made thinner. As a result, the material of the lower case can be saved.

Further, since the lower part of the upper case extends to the bottom of the lower case and is held therein, the height of the upper case, that is, the height of the push button switch as a whole can be reduced.

In addition, the push button switch can be closely fixed to the printed circuit board, and the height of the upper case, that is, the height of the entire push button switch can be reduced.
Even if you attach a key top to this push button switch,
Since the height from the printed circuit board to the top of the key top can be reduced, the keyboard can be made thinner.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the push button switch of this invention, FIG. 2 is a sectional view showing the state when the stem of FIG. 1 is pressed, and FIG. 3 is a plan view of FIG. 1. DESCRIPTION OF SYMBOLS 1... Lower case, 2-5... Side wall, 6... Bottom, 8, 9... Rib, 10, 11... Case fitting groove, 12... Upper case, 12a, 12b... Side wall, 14... ...Stem.

Claims (1)

[Scope of Claim for Utility Model Registration] The lower part of the upper case is fitted into the lower case, and a push button is held in the upper case so that it can move forward and backward toward the bottom of the lower case. In a push button switch that opens and closes contacts arranged on the bottom of the lower case, a rib is provided protruding from the bottom of the lower case in close proximity to the side wall, and the lower end of the upper case is fitted between the rib and the side wall. A push-button switch that is characterized by the following features: