JPS5941548Y2 - Cam mounting mechanism - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cam attachment mechanism for a push button switch or the like.

One type of push-button switch is called a push-button type.

With this type of switch, when you press the push button once, the push button stops in the pushed state and turns the switch ON (or OFF), and when you press it again, the push button returns to its original state and the switch turns OFF.
F (or ON).

As shown in FIG. 1, the operation of this push button switch is achieved by a specially shaped cam 2 mounted on the base plate 1 of the switch, and a pin 4 provided on the operating lever 3 side of the push button. This is done by sequential engagement as follows.

(1) First, when the push button is pressed, the operating lever 3 moves forward, and the pin 4 provided on it moves along the outer edge 2a of the tip of the cam 2, rotating the cam 2 around its shaft 5. .

(2) When the pin 4 reaches the notch 2b of the cam 2 and enters it, the cam 2 is rotated in the original direction by the action of the torsion spring 6 provided between it and the shaft 5.

As a result, the pin 4 is attached to the locking portion 2 on the center side of the notch 2b.
c, the operating lever 3 stops at this position, and the switch is turned on.

(3) In this state, when the push button is pressed again, the pin 4 comes off from the locking portion 2c and enters the depth of the notch 2b.

Then, the pin 4 starts to move back due to the action of the spring 7 that constantly presses the operating lever 3 toward the return side.

(4) A tapered protrusion 2d with an upwardly directed tip is formed on the front edge of the notch 2b, so the retreating pin 4 enters the lower surface of the cam 2 through this protrusion 2d. , passes under the cam 2 while lifting it, and as a result, the operating lever 3 returns to its original state as shown in FIG. 1, turning the switch OFF.

As described above, in the push button switch of the pushbutton type, the cam 2 that rotates left and right and up and down is mounted on the base plate 1. The one shown in Fig. 3 or Fig. 3 has been adopted.

First, in the conventional type shown in Fig. 2, a shaft 5 with a flange 5a integrally formed on the upper end is made of turned parts, the lower end of which is inserted into the mounting hole of the base plate 1, and caulked on the back side. .

However, this conventional type has the disadvantage that the shaft 5 may be bent during the caulking operation, and the operation is difficult because it requires special care.

In particular, in this conventional type, if a return torsion spring 6 is inserted between the base plate 1 and the cam 2 before the crimping work, the force of this spring tends to bend the shaft during crimping, resulting in incomplete installation. There were many cases where this happened.

On the other hand, in the conventional type shown in Fig. 3, the lower end of the shaft 5 cut out from the turned part is fixed to the base plate 1 by caulking, and then the cam 2 (and torsion spring 6) is attached to the upper part of the shaft 5 using the screw 5b. It is something that

This type has the advantage that the crimping work is relatively easy because there are no cams or torsion springs attached to the shaft during crimping work, but it was still necessary to be very careful not to bend the shaft.

Additionally, this conventional type requires more man-hours to tighten screws, and moreover, care must be taken to prevent the screws from loosening.

As described above, all conventional types require surface movement work such as caulking and joining, and they also have the disadvantage that due to problems such as shaft installation, the cam cannot operate normally and the push button locks incorrectly. there were.

In addition, in order to solve this problem, high precision is required in processing and assembling parts, resulting in an inconvenience of high costs.

The present invention was proposed to solve the above-mentioned drawbacks of the conventional type, and its purpose is to construct each member such as the shaft on which the cam is attached and the bushing for fixing the cam from plastic molded products. The purpose is to provide a ``cam mounting mechanism'' that can be fixed to a base plate with one touch.

Next, the present invention will be specifically explained based on the embodiments shown in FIG. 4 and below.

Figures 4 and 5 show an embodiment in which the base plate and the shaft are integrally molded from plastic.

In the figure, reference numeral 11 is a base plate, and 12 is a shaft integrally provided on the surface of the base plate 11.

Reference numeral 13 denotes a plurality of locking claws integrally formed on the back surface of the base plate 11. These locking claws 13 are arranged in a cylindrical shape, and each of the locking claws 13 has a bent portion 14 facing inward at its tip. It is formed.

An insertion hole 15 for a fixed bushing passes through the center of the shaft 12 and the locking pawl 13.

On the other hand, reference numeral 16 denotes a fixed bushing that is fitted onto the shaft 12. The fixed bushing 16 has a flange 17 at its top, and a bulge 1 that swells outward at the lower end of its shaft 18.
It has 9.

The outer diameter of this bulging portion 19 is such that it can enter into the insertion hole 15 of the shaft 12 and is larger than the gap between the bent portions 14 at the tips of each locking claw.

In order to attach the cam 20 to the base plate 11 using the attachment mechanism of this embodiment having the above-mentioned configuration, the following procedure is performed.

First, since the shaft 12 and the locking pawl 13 are already integrally molded with the base plate 11, the cam 20 (and torsion spring) is fitted onto the shaft 12.

Next, the shaft portion 18 of the fixed bushing 16 is inserted into the insertion hole 15 of the shaft 12, and the bulging portion 19 at the tip is engaged with the bent portion 14 at the tip of the locking claw.

In this case, since each locking claw 13 is made of plastic,
It is pushed by the bulge 19 of the fixed bushing and once expands outward, and after passing the bulge 19 it returns to its original position and locks it.

In this way, the cam 20 fitted onto the shaft 12 is held down by the flange 17 of the fixed bushing and is prevented from coming off the shaft 12.

Next, a second embodiment shown in FIGS. 6 and 7 will be described.

In this embodiment, the base plate, the shaft, and the locking pawl are separate bodies.

That is, in this embodiment, the shaft 12 and the locking pawl 13 are integrally molded from plastic.

A flange 21 is protruded from the base of the shaft 12 (the boundary between the shaft 12 and the locking pawl 13), and a circular recess 2 into which the flange 21 is fitted is provided on the base plate 11 side.
2, and a mounting hole 23 into which the locking claw 13 is fitted.

To install the cam 20 in the mechanism of this embodiment, the locking pawl 13 is inserted into the mounting hole 23 of the base plate 11, and at the same time, the flange 21 on the shaft side is inserted into the recess 2 of the base plate 11.
Fit into 2.

In this state, the shaft 12 is connected to the spring 24 and the cam 2.
0, and then insert the fixing bush 16 into the insertion hole 15.
When the shaft portion 17 is inserted, it is pushed open by the bulge at the tip of the bushing, and the locking pawl engages with the mounting hole of the base plate, so that the shaft 12 will not come out from the base plate 11.

At the same time, the fixed bushing 16 is also fixed to the shaft 12 because its distal end bulge and the distal end of the locking pawl engage, and the cam and 1.-
John spring is installed.

As described above, according to the present invention, it is possible to install the cam with a one-touch operation of simply fitting the fixed bushing into the insertion hole of the shaft. This has the effect of making installation extremely easy.

Further, since the shaft, the fixing bushing, and if necessary, even the base plate can be made of plastic molded products, parts with high dimensions and precision can be easily obtained.

Furthermore, the cost is lower compared to conventional types that use milled parts and screws, and by selecting plastic materials, it is possible to provide appropriate rigidity, so it is highly durable and reliable as a mechanical part. .

Incidentally, the mounting mechanism of the present invention can also be employed for mounting cams other than pushbutton switches of the pushbutton type.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a pushbutton type pushbutton switch, Figs. 2 and 3 are perspective views showing a conventional cam mounting mechanism, and Fig. 4 is a perspective view of a conventional cam mounting mechanism. 5 is a sectional view of the same, FIG. 6 is a perspective view of the second embodiment, and FIG. 7 is a sectional view of the same. 11...Base plate, 12...Shaft, 13
...Latching claw, 14...Bent part, 15.
...Insertion hole, 16...Fixing bush, 1
7...Flange, 18...Shaft part, 19
...Bulge, 20...Cam, 21...
...flange, 22 ... recess, 23 ...
...Mounting hole, 24...Tosho spring.

Claims (1)

[Scope of utility model registration request] A plurality of locking pawls are integrally formed at the bottom of the shaft, and these locking pawls are arranged in a cylindrical shape, and an insertion hole for a fixing bush passes through the center of the shaft. The locking pawl is integrated with the base plate, a cam is fitted on the outer periphery of the shaft, and the shaft of the fixed bushing is inserted into the insertion hole of the shaft and inside the locking pawl, and is locked with the tip of the shaft. A cam mounting mechanism characterized in that the cam is engaged with the tip of the claw, and a flange is formed on the upper end of the fixed bushing, thereby locking the cam so that it does not come out from the shaft.