JPH0526653Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is used in two-stage switches, specifically cameras or electrical products, in which two electrical contacts are sequentially closed with a single push stroke of the operation button. This relates to the structure of a two-stage switch.

[Prior Art] A two-stage switch in which a first contact is closed by the first stroke and a second contact is closed by the subsequent push stroke during one push stroke of an operation push button is conventionally known. Various configurations are available.

The most common type of switch is the so-called leaf switch, which consists of three thin elastic plates to form two contact points.
These are molded to maintain accurate spacing between them, and signal lines are connected to each of them to fix them to the main body of a camera or the like. Furthermore, two-stage switches using conductive rubber are also often used in calculators and the like. This two-stage switch has a conductive part on the board with a gold plating pattern,
An operation push button made of conductive rubber whose rubber shape is devised is pressed from above so as to sequentially close the two contacts. In addition, two-stage switches with a sliding switch structure or a rotary switch structure are also available.

[Problems to be solved by the invention] However, the conventional two-stage leaf switch mentioned above naturally requires three elastic thin plates, but in order to improve its reliability, these are used as a subassembly to ensure performance. Therefore, a molding process such as inserts is required. Therefore, this type of switch has a cost problem, and in the case of a leaf switch, since it requires elastic flexure, a relatively large space must be taken up on either side of the pressing part. Moreover, since the contact portions are arranged vertically, a relatively large space is required below the operation push button. In addition, the two-stage switch using conductive rubber has the disadvantage that the current capacity, that is, the current that can be passed, is limited, and the degree of freedom of the electric circuit is restricted.As a switch that uses the release button of a camera, etc. Not suitable. Furthermore, other sliding structures and rotary structures also have the problem of being complicated in structure and increasing cost.

Therefore, the purpose of the present invention is to eliminate the drawbacks of the conventional two-stage switch mentioned above, reduce the number of parts, lower costs, and increase reliability, while reducing the space occupied by the movable contact piece, and To provide a two-stage switch which is capable of passing a large current and is also suitable for using a camera release button as an operation push button.

[Means and effects for solving the problems] When configuring the two-stage switch according to the present invention, as shown in the electric circuits shown in FIGS. 4A, B, and C,
Two normally open electrical contact switches S ₁ and S ₂ are connected in parallel, and when the operation pushbutton is pressed, switch S 1 is always closed in the first stage (see Figure 4B), and then the switch S ₁ in the second stage is closed. The first stage switch _S1 must be closed before the second stage switch _S2 is closed so that the switch _S2 is closed (see Figure 4C).

In order to satisfy this condition and solve the above-mentioned problems, the two-stage switch of the present invention consists of a single elastic conductive plate, one end is fixed as a base end, the other end is a free end, and the tip a movable contact piece having a first contact part on the back surface of the part, and a second contact part on the back surface between the first contact part and the proximal end part; a first fixed contact member disposed at a position opposite to the second contact portion of the movable contact piece; and a first contact member and a second contact of the movable contact piece. a pushing means for applying a pressing force for closing the switch at a position on a straight line connecting the parts, the first contact part and the first fixed contact member are brought into contact by the initial pressing force by the pushing means. The second contact part moves using the contact point between the first contact part and the first fixed contact member as a fulcrum by the continuing pressing force, and comes into contact with the second fixed contact member. .

That is, in order to reduce costs, the elastic movable contact piece is made into one piece, two contact parts are provided on it, and two fixed contact members are formed for this contact part either singly or as a pattern on the substrate. The elastic movable contact piece is electrically connected to a certain signal. Since the first stage must come into contact first, the first and second contact parts are installed with the actuating pressing part sandwiched between the fixed end of the elastic movable contact piece. Also, after the first stage makes contact, the second stage approaches the contact point using the first stage's contact point as a fulcrum.
It is desirable to set the rigidity between the second stage contact part and the fixed part to be weak, and the first stage contact part - pressing part - 2
It is preferable that the straight line connecting the stage contact part and the straight line connecting the second stage contact part and the fixing part be at a substantially right angle or more, and by making an angle, the bulk of the entire switch can be reduced. I can do it.

[Example] First, before explaining the example of the present invention, the first
To explain the basic principle of this invention using Figures A, B, and C, the planar shape is U-shaped, U-shaped, or V-shaped.
Consists of a single thin elastic conductive plate with a character shape, etc.
The stepped end on one side of the conductive plate is fixed as a base end 1c, the other side is a free end, the back of the tip is the first contact part 1a, and the back near the bent part is the second contact part 1.
With respect to the movable contact piece 1 formed as b, a first fixed contact member 2 is disposed at a position opposite to the first contact portion 1a, and a second fixed contact member 3 is placed opposite to the second contact portion 1b. Place it in the desired position. Then, a pressing portion 4 that applies a pressing force for closing the switch is applied to a position near the first contact portion on the straight line connecting the first contact portion 1a and the second contact portion 1b of the movable contact piece 1.
shall be.

Then, when force F ₁ is applied to the pressing part 4 in FIG. 1A, the distance l ₁ from the pressing part 4 to the first contact part 1a, the distance l ₂ from the pressing part 4 to the bent part on the other side,
Distance from the stepped part of the base end 1c to the bent part of one side
If l ₃ , when force F ₁ is applied to the pressing part 4, l ₁ , l ₂ ,
Although it varies depending on l ₃ and the rigidity of the movable contact piece 1, generally if l ₁ < l ₂ , the first contact part 1a will always descend first and contact the first fixed contact member 2, and the first stage switch S ₁ (see Figure 4B) closes. At this time, the first
As shown in Figure B, the second contact portion 1b hardly goes down. Then, after the first stage switch S ₁ is in the closed state, when a force F ₁ is further applied to the pressing part 4, 1
A moment M is applied using the closing contact point of the tier, that is, the contact point between the first contact portion 1a and the first fixed contact member 2 as a fulcrum, and the second contact portion 1b of the second tier begins to descend.
At the same time, a larger force than before is required to press the pressing part 4, and a difference in strength (F ₂ >> _{F 1} ) occurs. Finally, as shown in FIG. 1C, the second contact portion 1b comes into contact with the second fixed contact member 3, and both the first stage switch _S1 and the second stage switch _S2 are closed.

2 and 3 are an exploded perspective view and a sectional view of a main part of a two-stage switch 10 showing an embodiment of the present invention. In this embodiment, the movable contact piece 11 is composed of a single elastic conductive thin plate having a substantially V-shaped planar shape, and the fixed contact member is formed by a printed pattern on a printed circuit board 15. ing.

The base end 11c of the stepped end of one side of the movable contact piece 11 is superimposed on the G pattern 16 formed by gold plating the surface on the substrate 15, and the base end 11c and the G Pattern 16 and substrate 1
It is disposed on the substrate 15 by a fixing screw 18 that penetrates through the main body substrate 17 and is screwed onto the main substrate 17. At this time, the positioning pin 17a planted on the main body board 17
Positioning holes 11d and 15a formed in the base end portion 11c and the base plate 15 are fitted to position the movable contact piece 11. A first contact portion 11a is formed on the back surface of the tip of the other side to protrude downward in a cone shape, and a first contact portion 11a is formed on the back surface of the bent portion to similarly protrude downward in a cone shape. A second contact portion 11b is formed, and on a substrate 15 facing both contact portions 11a, 11b, first fixed contact members 12, 13 are formed with a printed pattern whose exposed surfaces are gold plated. It is formed. In addition, both the contact portions 11a and 11b
A midpoint position on a straight line connecting the two is a pressing portion 14 that swells upward with a gentle slope. Immediately above this pressing portion 14, an operation push button 20 made of an elastic material such as rubber is attached to the exterior wall 19 so as to be freely depressed.

The two-stage switch 10 in this embodiment is installed in a camera, and the operation push button 20 is a rubber release button of the camera, and is attached to the camera exterior wall 19 with adhesive. .

In this embodiment configured in this way, when the operation push button 20 is pressed, the pressing part 14 is pushed and the first contact part 11a comes into contact with the first fixed contact member 12 first as explained in the principle diagram above. Then, the second contact portion 11b is moved to the second position by the pressing portion 14 which is further pressed.
The fixed contact member 13 is contacted, and the first stage switch _S1 and the second stage switch _S2 are sequentially closed. in this case,
1st stage switch S ₁ pattern (fixed contact member 1
If 2) is the first release and the pattern of the second stage switch _S2 (fixed contact member 13) is the signal line of the second release, then the above operation is the switching operation of the two stages of release.

[Effects of the Invention] As described above, according to the present invention, the number of parts is reduced, resulting in lower costs.

The order of closing timing of the first and second switches can be ensured accurately.

A larger current can flow than conventional switches using conductive rubber.

Since the portion occupied by the movable contact piece can be made small, the entire switch can be made compact.

It is possible to provide a two-stage switch that exhibits remarkable effects such as these and eliminates the drawbacks of conventional switches of this type.

[Brief explanation of drawings]

1A, B, and C are perspective views for explaining the operating principle of the two-stage switch of the present invention, FIG. 2 is an exploded perspective view of the two-stage switch showing an embodiment of the present invention, and FIG. This figure is a sectional view of the main part of the two-stage switch shown in FIG. 2, and FIGS. 4A, B, and C are electrical circuits showing the operating order of the two-stage switch. 1, 11...movable contact piece, 1a, 11a...first
Contact portion, 1b, 11b...Second contact portion, 1c, 1
1c... Base end portion, 2, 12... First fixed contact member, 3, 13... Second fixed contact member, 4, 14...
...pressing portion, 10...two-stage switch, _S1 ...first-stage switch, _S2 ...second-stage switch.

Claims (1)

[Claims for Utility Model Registration] Bent and formed in a U-shape, U-shape, or V-shape on substantially the same plane, one end of which is fixed as a base end, and the other end across the bent part is free. a thin plate-like movable contact piece having elasticity as an end portion; a first movable contact provided at the free end portion; a second movable contact provided at or near the bent portion; a first fixed contact provided at a position opposite to the movable contact; a second fixed contact provided at a position opposed to the second movable contact; and a position between the first movable contact and the second movable contact. The movable contact piece is provided with a pressing means for applying a pressing force from a direction substantially perpendicular to the plane, and the first movable contact is moved at the initial stage of pressing by the pressing means. is brought into contact with the first fixed contact, and by continued pressing, the second movable contact is moved using the contact point between the first movable contact and the first fixed contact as a fulcrum, and brought into contact with the second fixed contact. A two-stage switch characterized by the following features: