JPH0310582Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Field of the Invention>> The present invention relates to a microswitch, and particularly to an improvement of a microswitch suitable for a switch for preventing mistaken erasure in a magnetic recording device or the like.

<Prior art and its problems> In magnetic recording devices such as VTRs, a plurality of holes are formed in the cassette half of the cassette tape, each containing predetermined information such as information such as prevention of accidental erasure and recording time. A microswitch is arranged that detects the hole when the half is attached and obtains information based on the presence of the hole.

Although this microswitch has a small operating load, it is required to have a large stroke and high contact reliability.

Conventionally, as this type of microswitch, the one shown in FIG. 1 is known.

That is, the first fixed contact plate 2 and the second fixed contact plate 3 are mounted on the substrate 1 in abutting state with a space between them, and the first fixed contact plate 2 is placed on the second fixed contact plate 3. The movable piece 4 that is cantilevered toward the direction is bent in a dogleg shape, a contact portion 5 is formed on the lower surface of the movable piece 4 facing the second fixed contact plate 3, and the free end of the bent movable piece 4 is bent. The actuator pin 6 has a structure in which the base 7 of the actuator pin 6 is locked to the base 1, and the actuator pin 6 is freely projected from the through hole 9 of the box-shaped cover 8 placed over the base 1. .

In addition, the reference numeral 10 in the figure is a plug piece extending from the first and second fixed contact plates 2 and 3 and protruding from the side of the cover 8.

However, such microswitches require further improvement in order to obtain good reliability.

<<Purpose of the invention>> The present invention was made under these circumstances, and aims to provide a highly reliable microswitch that has a small operating load, a large operating stroke, and low contact resistance.

<Structure and Effects of the Invention> In order to achieve this object, the present invention arranges first and second fixed contact plates facing each other at a predetermined interval on the inner bottom of the case, and The first conductive plate spring piece fixed in contact with the first fixed contact plate is bent upward at a predetermined angle from the fixed part, and its tip is bent upward at a substantially right angle, and the second fixed contact plate is bent upward at a predetermined angle. The first one facing the contact plate
A first contact portion is formed on the lower surface of the conductive spring piece, and one end of a second conductive leaf spring piece, which is longer than the first leaf spring piece, is placed near the fixed base of the first leaf spring piece. A second contact portion is formed on the other end of the actuator pin, which is placed on the first leaf spring piece facing in the same direction, and is attached to an actuator pin that is provided so as to be able to move out of the case. The tip of the second conductive leaf spring piece is brought into contact with the second conductive leaf spring piece and biased in the direction of protruding out of the case,
The contact point between the actuator pin and the second leaf spring piece is the point of force, the locking point of the second leaf spring piece is the fulcrum, and the bent tip of the first leaf spring piece and the second leaf spring piece Due to the principle of lever, where the point of contact is the point of action,
The first contact portion is brought into pressure contact with the second fixed contact plate in conjunction with the retraction movement of the actuator pin, and the second leaf spring piece is bent using the contact portion with the bent portion as a fulcrum. The second contact portion is pressed onto the second fixed contact plate.

According to the configuration of the present invention, the load required to operate the switch is reduced, but the stroke is increased, and the contact resistance of the contact portion is reduced, so that reliability can be further improved.

<<Description of Examples>> The details of the present invention will be described below. Note that parts common to the conventional example are given the same reference numerals.

FIGS. 2 and 3 are a sectional view and a perspective view showing an embodiment of the microswitch of the present invention.

In both figures, the case 11 is constructed by placing a box-shaped cover 8 on a board 1, and on the board 1 forming the inner surface of the case 11 are a first fixed contact plate 2 and a second fixed contact plate 3. A plurality of sets are fixed so as to face each other at a predetermined interval.

A first electrically conductive leaf spring piece 12 is fixed to the first fixed contact plate 2 so as to be in contact with the second fixed contact plate 3 so as to support the second fixed contact plate 3 in a cantilevered manner. This first conductive leaf spring piece 12 is bent upward at a predetermined acute angle at the supported base, and has an upright bent part 13 bent upward at a substantially right angle in the middle thereof. and the second fixed contact plate 3
A first contact portion 14 is formed on the lower surface facing the.

A locking portion 15 is formed at the inner end of the cover 8 facing the first fixed contact plate 2.
a second conductive leaf spring piece 1 having one end locked to 5;
6 is the upright bent portion 1 of the first conductive leaf spring piece 12
It is placed at the tip of 3.

The second conductive leaf spring piece 16 is longer than the first conductive leaf spring piece 12, and its tip is curved so as to protrude toward the second fixed contact plate. The contact portion 17 is formed as a contact portion 17.

The vicinity of the second contact portion 17 of the second conductive leaf spring piece 16 is located at the base 7 of the actuator pin 6.
The actuator pin 6 is brought into contact with the actuator pin 6 and applies an urging force to the actuator pin 6.

The actuator pin 6 is disposed so as to be freely protrusive and retractable from a through hole 9 formed in the cover 8, and when located at the uppermost position, a flange 18 provided on the base 7 comes into contact with the inner surface of the cover 8. .

Note that the reference numeral 10 is a plug piece for external connection that extends from the first fixed contact plate 2 and the second fixed contact plate 3 through the side of the case 11.

In the micro switch configured in this way, when no load is applied to the actuator pin 6, the first conductive leaf spring piece 12 pushes up the second conductive leaf spring piece 16, so that the first contact point Part 14
There is no contact between the second fixed contact plate 3 and the actuator pin 6, which also protrudes from the case 11.

On the other hand, when actuator pin 6 is pushed down,
Actuator pin 6 and second conductive leaf spring piece 1
The contact point A with 6 is the point of force, and the second conductive plate spring piece 1
6, the first conductive plate spring piece 12
The first conductive leaf spring piece 12 is pushed down by the principle of leverage, which uses the point of contact C between the bent tip of the conductive leaf spring piece 16 and the second conductive leaf spring piece 16 as the point of action.
The second fixed contact plate 3 of the contact portion 14 contacts.

Furthermore, when the actuator pin 6 is pushed down, the second conductive plate spring piece bends at the contact point C, as shown in FIG. Pressed onto the top.

Therefore, since the first and second fixed contact plates 2 and 3 are in contact with each other through the two contact portions 14 and 17, it is possible to reduce the contact resistance of the contact portions, thereby increasing reliability.

As explained above, the microswitch of the present invention is capable of obtaining a large stroke with a small load, and the contact resistance of the contact portion is also reduced, thereby improving reliability.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional micro switch, Figs. 2 and 3 are sectional views and perspective views showing an embodiment of the micro switch of the present invention, and Fig. 4 is a perspective view showing a conventional micro switch.
This figure is a cross-sectional view illustrating the operation of the microswitch shown in FIG. 3. 1... Board, 2... First fixed contact plate, 3...
second fixed contact plate, 6...actuator pin,
8...Cover, 11...Case, 12...First conductive leaf spring piece, 13...Bending portion, 14...First
15...Locking part, 16...Second conductive leaf spring piece, 17...Second contact part.

Claims (1)

[Claims for Utility Model Registration] First and second fixed contact plates that are disposed facing each other at a predetermined distance from each other at a predetermined distance from each other at the bottom of the case, and that are electrically connected to plug pieces that each protrude outside of the case. ; Abuts against the first fixed contact plate side and is fixed toward the second fixed contact plate side, is bent upward at a predetermined angle at its fixed base, and is further bent approximately upward at its tip end; a first electrically conductive leaf spring piece that is bent at a right angle and has a first contact portion formed on the lower surface of its tip facing the second fixed contact plate; The first leaf spring piece is placed toward the fixed base portion of the first plate spring piece, and one end thereof is locked near the fixed base of the first leaf spring piece, and a second contact portion is formed on the lower surface of the other end portion. a second conductive leaf spring piece formed to be longer than the leaf spring piece; provided so as to be freely protrusive and retractable into the case, and whose inner end portion touches the top surface of the tip end of the second conductive leaf spring piece; an actuator pin that is urged in a direction to protrude out of the case; the point of contact between the actuator pin and the second leaf spring piece is the point of contact; According to the lever principle, in which the locking point is the fulcrum and the point of contact between the bent tip of the first leaf spring piece and the second leaf spring piece is the point of action, the above-mentioned The first contact portion is brought into pressure contact with the second fixed contact, and the second leaf spring piece is bent using the contact portion with the bent tip portion as a fulcrum, so that the second contact portion is brought into contact with the second fixed contact. A micro switch characterized in that it is configured to be pressed into contact with a second fixed contact plate.