JPH0334037Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention relates to a structure for attaching a push button of a small switch in which contacts can be opened and closed by vertical movement of the push button.

(b) Prior art A conventional small switch in which the lower end of a push button is locked to a movable spring member equipped with a movable contact, for example, protects electronic equipment by interrupting the circuit when excessive current flows. For conventional small switches, where the circuit is closed when the push button is pushed in and the circuit is broken when the push button is pulled up, the push button The push button was attached in such a manner that it protrudes from the upper surface of the housing both when it is in the pulled up state by the upward movement operation and when it is in the pushed state by the downward movement operation.

(c) Problems to be solved by the invention However, if the push button protrudes from the top surface of the housing, there is a risk that a hand or an object may accidentally press the push button. For example, in the small switch, if the push button is accidentally pressed while the circuit is closed, excessive force is applied to the movable spring member, which may damage the movable spring member or the contacts. Furthermore, if the pushbutton is accidentally pressed while the circuit is interrupted, the contacts will switch erroneously, resulting in malfunction.

Further, if the push button is configured to protrude from the upper surface of the housing both when it is pushed in and when it is pulled up, it is difficult to clearly determine whether the contact is open or closed.

In this way, in conventional small switches, the push button always protruded from the top of the housing, which caused problems such as the push button being accidentally pressed, damaging the contacts or malfunctioning, and making it impossible to clearly determine whether the contacts were open or closed. It was hot.

The purpose of this invention is to solve these problems, and to provide a push button mounting structure that can prevent the push button from being accidentally pressed without the need for additional special parts. shall be.

(d) Means for solving the problem In the push button mounting structure of this invention, the lower end of the push button is locked to a movable spring member of the switch main body, and when the push button is moved up and down, the movable spring member In a small switch, the push button is made to swing to open and close the contacts, and the push button stops at a pushed-in position and a pulled-up position when the contact opens and closes. , the push button is arranged so that its upper end is flush with a portion of the upper surface of the housing adjacent to the push button when the push button is stopped in the pushed-in position or in the pulled-up position; A groove is formed in the push button, and the push button is exposed in a direction perpendicular to the longitudinal direction of the housing.

(e) Effect The push button mounting structure according to this invention is configured such that when the push button is stopped at the pushed-in position, the upper end thereof is flush with the portion of the upper surface of the housing adjacent to the push button. If the push button is pressed in, even if a hand or an object hits the push button, the upper surface of the housing prevents the push button from being pressed erroneously. Nevertheless, when manually pulling up the push button, a screwdriver or the like can be inserted into the recessed groove to pull it up, so there is no problem in pulling up the push button.

Further, the open/closed state of the contact can be clearly determined simply by checking whether the upper end of the push button protrudes from the upper surface of the housing.

If the pushbutton is configured so that its top edge is flush with the portion of the top of the housing adjacent to the pushbutton when it is stopped in the raised position, then the pushbutton is not pushed in or pulled up. The upper surface of the housing prevents the push button from being pressed accidentally, regardless of whether the push button is pressed or not. The push button can be reset by inserting a screwdriver etc. into the groove.

In addition, the open/closed state of the contact can be clearly determined by simply checking whether the upper end of the push button is flush with the upper surface of the housing or inserted into the recessed groove.

(f) Embodiment FIG. 1 is a sectional view showing a small switch employing a push button mounting structure according to an embodiment of the invention, and FIG. 2 is an external perspective view of the small switch.

As shown in FIG. 1, the small switch includes a box-shaped housing 1 and a switch main body 2 housed in the housing 1 and equipped with a push button 3 for operation.
It consists of. The switch main body 2 includes a fixed part 5 to which the base end 4a of the bimetal plate 4 is fixed, a locking part 7 having locking grooves 7a and 7b in which the movable spring member 6 is locked, and a fixed contact piece 8. are held on the base 9, a first terminal pin 11 extending to the locking part 7, a second terminal pin 12 extending to the fixing part 5, and the fixed contact piece 8. A third terminal pin 13 extending from the base 9 is led out to the outside of the base 9. Further, a first fixed contact 14 is attached to the free end of the bimetal plate 4, a second fixed contact 15 is attached to the end of the fixed contact piece 8, and a movable spring member 6
A movable contact 16 is attached to the free end of.
Note that the locking grooves 7a and 7b are formed at different heights.

The push button 3 has bifurcated legs 20, 20.
It is made of a plastic molded product with recesses 22, 22 provided in the intermediate portions of these leg portions 20, 20, and guide surfaces 21, 21 extending downward in the lower half. The lower end of the push button 3 is locked to the bridging piece 6a of the movable spring member 6. This locking is achieved by fitting the bridging pieces 6a of the movable spring member 6 into the recesses 22, 22 while using the guide surfaces 21, 21 while the legs 20, 20 are slightly expanded against their elasticity. Therefore, it can be done easily and reliably.
Further, a groove 23 is formed in the upper side of the push button 3.

As shown in FIG. 2, a groove 24 extending in a direction perpendicular to the longitudinal direction of the housing 1 is formed approximately at the center of the upper surface of the housing 1. The top is exposed. Then, as shown in Fig. 1, the movable contact 1
6 is in contact with the first fixed contact 14,
The upper end 3a of the push button 3 is connected to the concave groove 2 of the housing 1.
The upper surface 1a, 1 adjacent to the push button 3 on both sides of 4
It is flush with a.

In such a small switch, in a normal state, the movable spring member 6 is stopped at a first stable point shown by a solid line in FIG. 1, and the movable contact 16 is in contact with the first fixed contact 14. Therefore, the upper end 3a of the push button 3 is flush with the portions of the upper surfaces 1a, 1a adjacent to the push button 3 on both sides of the groove 24 of the housing 1, and by visually checking this, it is possible to reduce the size. It can be determined that the switch is maintained in the normal state. Further, when a hand or an object touches the push button 3, the hand or object also touches the upper surfaces 1a, 1a of the housing on both sides at the same time, so there is no fear that the push button 3 will be pressed accidentally.

From this normal state, the first terminal pin 11 and the second
When an overcurrent flows between the terminal pins 12, the bimetal plate 4 begins to warp upward due to the generated heat, and as a result, the movable end 6c of the arcuate snap spring 6b integrally formed with the movable spring member 6.
is gradually displaced upward. Then, when the movable end 6c crosses the critical line X of the snap spring 6b,
At that point, the snap spring 6b is reversed. Along with this, the movable spring member 6 instantaneously performs a so-called snap operation upward until the movable contact 16 hits the second fixed contact 15, and is located at the second stable point shown by the imaginary line in the figure, and the movable spring member 6 The contact between the fixed contact 14 and the movable contact 16 is broken. This protects electronic equipment. Further, with the snapping action of the movable spring member 6, the push button 3 is pushed up, and the upper end 3a of the push button 3 is pushed up.
is stopped at a position where it is lifted up from the upper surfaces 1a, 1a of the housing 1. Therefore, by visually confirming this, it can be determined that the circuit is interrupted by the small switch.

After removing the cause of the excessive current flow, to return the movable spring member 6 to its original state, push the push button 3 to return the movable spring member 6 to the first stable point. Further, in order to artificially lift up the push button 3 from the pressed state, a screwdriver bit or the like inserted through the groove 24 is hooked onto the groove 23 and lifted up.

In the small switch shown in FIG. 2, if the groove 23 of the push button 3 is colored, there is an advantage that the position of the push button 3 can be identified more clearly.

In this embodiment, the upper end of the push button is flush with the upper surface of the housing when the push button is pushed in.
The upper end of the push button may be flush with the upper surface of the housing when the push button is pulled up. In the latter case, the open/closed state of the contact can be determined by checking whether the upper end of the push button is flush with the upper surface of the housing or inserted into the groove.

In the small switch, the direction in which the bimetal plate 4 warps when an overcurrent flows is the first fixed contact 14.
Since this direction corresponds to the direction in which pressure contact force is applied to both the movable contact 16, the contact pressure between the contacts does not weaken until both contacts 14 and 16 are about to open, and the contact state between the contacts is maintained stably. However, the separation is instantaneous. Therefore, it is preferable as a small switch.

As shown in FIG. 2, in the small switch, the position of the push button 3 is set at
It is shifted in the width direction by a predetermined dimension m.
By doing this, even when assembling two or more small switches side by side, the distance between the through holes on the printed wiring board and the terminal pins 11 and 1 can be adjusted.
It becomes possible to match the intervals such as 2 and 13. Further, if the terminal pins 12, 13 are formed with wave-shaped protrusions 25, 26, there is an advantage that the terminal pins 12, 13 can be press-fitted into the through holes.

(g) Effects of the device According to the device configured as described above, the upper surface of the housing prevents the push button from being pressed accidentally, so there is no need to apply excessive force to the movable spring member or the contact. This ensures that they cannot be damaged or malfunction in the first place. Further, by looking at the position of the upper end of the pushbutton using the upper surface of the housing as a reference surface, the open/closed state of the contact can be easily and clearly determined.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional front view of a small switch which is an embodiment of this invention, and FIG. 2 is a perspective view of the same external appearance. 1...housing, 1a...housing top surface,
2...Switch body, 3...Push button, 3a...
Upper end of push button, 6... Movable spring member, 14...
...First fixed contact, 15... Second fixed contact, 16...
...Movable contact, 24...concave groove.

Claims (1)

[Claim for Utility Model Registration] The lower end of the push button is locked to a movable spring member of the switch main body, and the movable spring member is swung by the vertical movement of the push button to open and close the contacts. , and a small switch in which the push button stops at a pushed-in position and a pulled-up position when the contact is opened and closed, wherein the push button stops at the pushed-in position. The push button is disposed so that its upper end is flush with a portion of the upper surface of the housing adjacent to the push button when the push button is pressed or stopped in the raised position, and in a direction perpendicular to the longitudinal direction of the housing. A structure for attaching a push button of a small switch, characterized in that a concave groove is formed in which the push button is exposed.