JPS6242435Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a switch mechanism used for example in a time switch, more specifically, a switching contact piece is provided on both sides of a common contact piece, and the common contact piece and one switching contact piece are driven by a cam. This invention relates to a switch mechanism that exclusively switches contacts.

Conventionally, this type of switch mechanism has a common contact piece 1 and two switching contact pieces 2 and 3, as shown in FIG.
cams 5 and 6 are provided to drive the common contact piece 1 and one of the switching contact pieces 2, and the cams are set at a predetermined position by setters 8 and 9 attached to the dial 7. There has been provided a device in which the contacts are switched by rotating the contact point by angle as shown in FIGS. 2 and 3. A spacer 10 is provided between the tips of the switching contact pieces 2 and 3, and the spacer 10 maintains the distance between the tips of the switching contact pieces 2 and 3 to a predetermined value or more.
Either one of the switching contacts is configured to exclusively contact the common contact 1a.

This spacer 10 has a small diameter shaft portion 10a at one end.
The shaft portion 10a is attached by passing through the hole 3a of one of the switching contact pieces 3, but for operational function, the shaft portion 10a must slide smoothly within the hole 3a. However, since the switching contact piece 3 is generally made of a thin spring plate, the spacer 10 does not fit into the hole 3.
The shaft 10a swings significantly relative to a, making it impossible to achieve smooth sliding between the hole 3a and the shaft portion 10a, and causing severe wear on the shaft portion 10a. Therefore, the contact stability of the contacts decreases,
Another disadvantage was that the rotational torque of the cam also increased.

The present invention was developed in view of the above drawbacks, and its purpose is to improve the contact reliability of the contact by fixing a spacer of a predetermined length to the tip of one switching contact piece, and to improve the rotation of the cam. It is an object of the present invention to provide a switch mechanism that solves the problem of increased torque.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing embodiments thereof.

4a to 4d show a first embodiment of the switch mechanism according to the present invention, in which switching contacts 14 are provided on both sides of a common contact piece 11 having a common contact 12, and
Switching contacts 13, 15 having 16 are arranged, and these contacts 11, 13, 15 are fixed to an insulating base 17. On the tip side of the contact piece, there is a cam 18, 1 that is intermittently rotated by 45 degrees by a drive mechanism (not shown).
9 are provided in upper and lower stages, the tip 13a of the lower switching contact piece 13 in the figure (hereinafter referred to as the first switching contact piece) contacts the upper cam 18, and the lower cam 19 has a common contact piece. The tips 11a of 11 are in contact with each other.
A spacer 20 made of synthetic resin is fixed by molding to the tip 15a of the upper switching contact piece 15 in the figure (hereinafter referred to as the second switching contact piece) that does not contact the cam, and the tip surface of this spacer 20 It abuts against or faces the tip 13a of the first switching contact piece 13 with a gap therebetween.

The operation of the switch mechanism constructed as above is almost the same as that of the conventional one. That is, in Fig. 4a, the tip 11a of the common terminal 11 is pushed up by the crest of the lower cam 19, while the tip 13a of the first switching contact 13 falls into the valley of the upper cam 18, so that the contact 16 of the second switching contact 15 is pressed against the common contact 12, and the tip surface of the spacer 20 and the tip 13a of the first switching contact 13 are separated.
4b, the tip 11a of the common contact 11 attempts to fall into the valley of the lower cam 19, and the gap g between the tip face of the spacer 20 and the tip 13a of the first changeover contact 13 becomes minimum. Then, when the cam further rotates to the state shown in Fig. 4c, the tip 11a of the common contact 11 falls into the valley of the lower cam 18, and the tip face of the spacer 20 abuts against the tip 13a of the first changeover contact 13, so that the contact 14 of this changeover contact 13 and the common contact 12 are pressed together, switching the contacts and stopping the rotation of the cam.

When the cams 18 and 19 rotate in the direction of the arrow from this state, the state shown in FIG. 4d is reached, and all three contact pieces are pushed upward in the figure, and the first switching contact piece
The tip 13a of the cam 18 is about to fall off the top of the cam 18. When the cam rotates further, the tip 13a of the first switching contact piece 13 falls from the peak of the upper cam 18, and the contact switches again to the state shown in FIG. 4a, and the cams 18 and 19 rotate. The movement stops.

In the above operation, contact 1 of the first switching contact piece 13
In order to widen the contact gap G1 between the contact _{point 16} of the second switching contact piece 15 and the common contact point 12, and the contact gap _G2 between the contact point 16 of the second switching contact piece 15 and the common contact point 12, a spacer 20 is used.
It is preferable to increase the protrusion length l, but if this length l is increased, the minimum gap g shown in FIG. 4b cannot be maintained. In other words, if the gap g cannot be taken, the spacer 20 and the first switching contact piece 13
When they come into contact with each other, the contact pressure between the contact 16 and the common contact 12 decreases, resulting in unstable contact. Therefore, the protrusion length l of the spacer 20 is necessarily determined so that the gap g does not become zero in the state shown in FIG. 4b.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, a spacer 2 made of a square-shaped synthetic resin is attached to the tip 13a of the first switching contact piece 13 that contacts the cam 18.
1 is fixed. Particularly in this case, unlike the first embodiment, there is no need to bend the tip 13a of the first switching contact piece 13, so dimensional accuracy is improved and more stable switch operation can be obtained. . Note that the operation in this case is similar to that of the first embodiment.

FIG. 6 shows a third embodiment of the present invention, in which a spacer 23 having an engagement groove 23a is fitted and fixed to the tip end 22a of the common contact piece 22 from the side. In this case, there is an advantage that manufacturing and assembly costs can be reduced compared to resin molding.

As is clear from the above explanation, according to the present invention, a spacer with a predetermined protruding length is integrally fixed to the tip of one of the common contact pieces, so that the sliding property is not improved as in the conventional case. It's no longer a problem,
Contact reliability is improved and cam rotational torque does not increase. Therefore, reliable and stable switch operation can always be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the switch mechanism of a conventional time switch, Figs. 2 and 3 are plan views of its main parts, Fig. 4 and the following show the present invention, and Figs. 4a to 4d show the present invention. A plan view showing the operation of the first embodiment, the fifth
The figure is a plan view of the second embodiment. FIG. 6 is an exploded perspective view of the switching contact piece and spacer of the third embodiment. 11... common contact piece, 12... common contact point, 13,
15...Switching contact piece, 14, 16...Switching contact, 1
7... Insulation stand, 18, 19... Cam, 20, 2
1, 23...Spacer.

Claims (1)

[Scope of utility model registration request] A common contact piece having a common contact on both sides and two switching contacts having a switching contact on the inner side are fixed to an insulating stand so that the common contact is located between the switching contacts, and the common contact The tip of the switching contact and the tip of one of the switching contact pieces are each driven by a cam, and a spacer is provided to maintain the distance between the tips of both switching contact pieces at a predetermined value or more. In a switch mechanism configured such that a contact contacts exclusively with one of the switching contacts, the spacer is integrally fixed to the tip of one of the switching contacts, and the spacer has a protruding length l. The switch mechanism has a length such that when the switching contact of the switching contact that does not contact the cam is in contact with the common contact, there is a gap g between the front end surface of the spacer and the opposing surface of the other switching contact.