JPH0433614Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a drip-proof structure for a push-button switch, and is particularly suitable for a drip-proof structure for a push-button switch attached to an operating section of a medical device. Regarding structure.

(Prior Art) Conventionally, a membrane switch as shown in Fig. 2 has been used as a drip-proof structure to prevent liquid from entering from the mounting part of a push button switch attached to an operating part of a medical device. It was common. That is, a key head 4 mounted on a panel 3 so as to be movable in the axial direction is provided on the upper part of a switch main body 2 mounted on a printed circuit board 1. A sheet panel 5 is glued onto said panel 3.

However, with the drip-proof structure of the conventional push button switch as described above, there is a problem in that the operating stroke of the key head 4 is restricted and a large stroke cannot be obtained. As a result, it did not give a good click feeling and was difficult to operate.

(Problems that the invention aims to solve) This invention solves the problem of the drip-proof structure of conventional push button switches, which is covered with a sheet panel, so a large operating stroke cannot be obtained, and a good clinic feeling cannot be obtained. To provide a drip-proof structure for a push button switch that solves the problem of difficulty in operation, provides a large operating stroke, is easy to operate, and reliably prevents liquid from entering the substrate mounting area. purpose.

[Structure of the invention] (Means for solving the problem) In order to achieve the above-mentioned purpose, the present invention presses the key head mounted on the panel on the switch body mounted on the board to operate the switch. In the drip-proof structure of a push button switch that turns on and off, the key head is inserted into a through hole drilled in the panel, and a conical skirt is connected to the outer periphery of the lower end of the key head. A ring-shaped rib is connected along the tip of the skirt, and a switch contact portion that presses the switch body is protruded from the lower end surface of the key head, and the key head, the skirt, the rib, and the switch contact The ring-shaped rib is tightly sandwiched between the panel and a lower panel that is fixed to the panel via a spacer and has a through hole through which the switch contact portion is inserted. It is composed of

(Function) According to the above configuration, since the key head is elastically supported by the ribs via the skirt, the operating stroke of the key head can be increased.
Further, the ring-shaped rib is integrally connected to the skirt and tightly sandwiched between the upper panel and the lower panel, so that it is possible to prevent liquid from entering the board from the key head side.

(Example) Hereinafter, an example of the drip-proof structure of a push button switch according to the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In this figure, parts that are the same or equivalent to those of the conventional example shown in FIG. 2 are denoted by the same reference numerals, and explanations thereof will be omitted. A lower panel 7 is fixed to the lower part of the upper panel 3 via a spacer 6. A key head 4 made of an elastic material such as synthetic resin is movable in the axial direction in a mounting hole 8 provided through the upper panel 3 and the seat panel 5 covering the upper surface of the upper panel 3. is installed on. Further, a hole 9 is formed in the spacer 6 concentrically with the mounting hole 8 and having an inner diameter larger than the mounting hole 8, and a hole 9 is formed in the lower panel 7 concentrically with this hole 9 and smaller than the hole 9. A hole 10 with an inner diameter is formed. A switch contact part 11 integrally formed on the lower surface of the key head 4 is inserted into this hole 10. When the key head 4 is pressed, the switch contact part 11 pushes the switch body 2, and the switch is activated. It has started to be used for entrance and exit. A conical skirt 12 is integrally formed around the entire circumference at the lower end of the outer circumference of the key head 4, and a ring-shaped rib 13 is further integrally formed at the lower end of this skirt 12. ing. This rib 13 is tightly sandwiched between the upper panel 3 and the lower panel 7.

Next, the operation of this embodiment will be explained. When the key head 4 is pressed, the switch body 2 is pushed through the switch contact portion 11 to turn the switch on and off. At this time, the key head 4, skirt 12, and rib 13 are integrally formed of elastic synthetic resin.
Furthermore, since the ribs 13 are tightly sandwiched between the upper panel 3 and the lower panel 7, liquids and the like from outside the upper panel 3 will not infiltrate downward from the lower panel 7. Moreover, the elastic deformation of the skirt 12 makes it possible to increase the operating stroke of the key head 4. When the pressure on the key head 4 is released, the key head 4 returns to its original position due to the return force of the switch contacts of the switch body 2 and the return force of the skirt 12.

According to this embodiment, since the operating stroke of the key head 4 can be increased, a good click feeling can be obtained and the operability can be improved. Furthermore, since the ribs 13 are tightly sandwiched between the upper and lower panels 3 and 7, a complete drip-proof effect can be obtained. Furthermore, the key head 4, skirt 12, and rib 13 are integrally molded from synthetic resin. Therefore, it can be made widely versatile at low cost.

In the above embodiment, a case has been described in which the sheet panel 5 is provided on the upper surface of the upper panel 3, but this sheet panel 5 may be omitted. Further, the switch contact portion 11 may be constructed separately from the key head 4.

[Effects of the invention] As described above, according to the invention, a ring-shaped rib is integrally formed on the outer periphery of the lower end of the key head of the push button switch via a skirt, and this rib is tightly sandwiched between the upper and lower panels, which makes manufacturing easier. In addition to being easy to use, it is possible to completely prevent liquid from entering the interior, and the operating stroke of the key head can be increased, resulting in a pleasant click feeling and improved operability.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing an embodiment of the drip-proof structure of a push-button switch according to the present invention, and FIG. 2 is a side view showing the drip-proof structure of a conventional push-button switch. 1... Board, 2... Switch body, 3... Upper panel, 4... Key head, 6... Spacer, 7...
...Lower panel, 11...Switch contact part, 12...
...Skirt, 13...Rib.

Claims (1)

[Scope of utility model registration request] In the drip-proof structure of a push button switch, in which the key head mounted on a panel is pressed against the switch body mounted on a circuit board to turn the switch on and off, the key head is connected to a through hole drilled in the panel. A conical skirt is provided on the outer periphery of the lower end of the key head, a ring-shaped rib is provided along the tip of the skirt, and the switch is inserted into the lower end surface of the key head. A switch contact portion for pressing the main body is provided protrudingly, the key head, the skirt, the rib, and the switch contact portion are integrally formed of an elastic member, and the ring-shaped rib is connected to the panel and a spacer is attached to the panel. A drip-proof structure for a push-button switch, characterized in that the push-button switch is tightly sandwiched between the lower panel, which is fixed via a panel, and has a through-hole through which the switch contact portion is inserted.