JPH035057Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a membrane switch, and particularly to a novel membrane switch equipped with both make and break contacts.

(b) Prior Art As is well known, a membrane switch S' has a movable contact 3a' formed on an upper sheet 3' and a fixed contact 5a' formed on a lower sheet 5', as shown in FIG. The make contact structure is such that the movable contacts 3a' and the fixed contacts 5a' are made to face each other and are separated by the thickness of the spacer sheet 4', and are brought into electrical contact by pressing down the upper layer sheet 3'.

(c) Problems to be Solved by the Invention By the way, the form of contact signal input for devices often requires not only a make contact input but also a break contact input. It has been desired to provide a membrane switch, and this invention is an attempt to realize that goal.

(d) Means for solving the problem This invention provides a first spacer capable of holding a first upper layer sheet on which movable contacts are formed and a first lower layer sheet on which fixed contacts are formed at a predetermined distance between the two contacts. A second spacer capable of holding a second upper layer sheet on which a fixed contact is formed and a second lower layer sheet on which a movable contact is formed at a predetermined distance between the two contacts. The sheets are laminated with sheets interposed therebetween to form a break contact portion, and are laminated below the first lower sheet with a spacer base material interposed therebetween. A pusher having an upper flange and a lower flange formed on the peripheral edge and the lower periphery is inserted, and the upper flange can be brought into contact with the upper surface of the first upper layer sheet, and the lower flange can be brought into contact with the lower surface of the second lower layer sheet, respectively. A reversing spring is inserted on the base material below the shaft of the pusher, and the pusher is pressed upward by the reversing spring. This is a membrane switch that features both make and break contacts.

This invention will be explained below based on the drawings.

FIG. 1 is a schematic sectional view showing a contact portion of a membrane switch S1 of the make and break contact type according to this invention.

In the figure, 1 is a top sheet, 2 is a spacer sheet, 3 is an upper layer sheet, 4 is a spacer sheet, 5
is a lower layer sheet, 6 is a spacer base material, 7 is an upper layer sheet, 8 is a spacer sheet, 9 is a lower layer sheet, 10
1 is a spacer sheet, 11 is a base material, 12 is a pusher, and 13 is a reversal spring. Upper layer sheet 3,
7. Both of the lower sheets 5 and 9 are flexible wiring sheets in which contacts and conducting wires are formed by screen printing silver and carbon on a polyester film, for example, and an annular movable contact 3a is provided on the lower surface of the upper sheet 3, and the lower layer On the upper surface of the sheet 5, similarly annular fixed contacts 5a are formed at opposing portions on the surface, forming make contact portions. Through holes 3b and 5b are formed in the center of each of the annular movable contact 3a and fixed contact 5a, respectively.
A spacer sheet 4 is interposed between the upper sheet 3 and the lower sheet 5, and a through hole 4a is formed at a location corresponding to a contact portion consisting of a movable contact 3a and a fixed contact 5a. are held constant and facing each other by the thickness of the spacer sheet 4 when there is no downward pressing force of the upper layer sheet 3. A spacer base material 6 is laminated on the lower surface of the lower sheet 5 and fixes the lower sheet 5. Furthermore, an upper layer sheet 7 is fixed to the lower surface of this spacer base material 6. An annular fixed contact 7a and a movable contact 9a are provided on the lower surface of the upper sheet 7 and the upper surface of the lower sheet 9, respectively.
are formed at opposing portions on the surface, respectively, and constitute a break contact portion. A through hole 7 is provided in the center of each of the annular fixed contact 7a and movable contact 9a.
b, 9b has been opened. A spacer sheet 8 is interposed between the upper layer sheet 7 and the lower layer sheet 9, and a through hole 8a is bored at a location corresponding to a contact portion consisting of a fixed contact 7a and a movable contact 9a. are held constant and facing each other by the thickness of the spacer sheet 8 when there is no upward pressing force on the lower sheet 9. Lower sheet 9
A spacer sheet 10 is laminated on the lower surface, and this spacer sheet 10 has a through hole 10a. In addition, a spacer sheet 2 is placed on the upper surface of the upper layer sheet 3.
A top sheet 1 is laminated with the top sheet 1 interposed therebetween. The top sheet 1 has a key operation section drawn on its top surface. An upper flange 12a is provided in the space formed by the top sheet 1, the spacer sheet 2, and the upper layer sheet 3, that is, in the through hole 2a of the spacer sheet 2, and the upper layer sheet 3, the spacer sheet 4, the lower layer sheet 5, and the spacer base 6. Through holes 3b, 4a, 5b, 6a, 7b, 8 formed in the upper sheet 7, spacer sheet 8, lower sheet 9 and spacer sheet 10, respectively
A pusher 12 is inserted into the space formed by the spacer a, 9b, and 10a, and has a shaft portion 12b, and further has a lower collar portion 12c in the space formed by the through hole 10a of the spacer sheet 10. The shaft portion 12 of this pusher 12
An inversion spring 13 formed in a dome shape is in contact with the bottom surface b at its top 13a. Reversing spring 1
3 is fitted into a recess 11a formed in a base material 11 made of Bakelite or the like and laminated on the lower surface of the spacer sheet 10. In the normal state (when the reversing spring 13 is not reversed), the pusher 12 pushes up the lower sheet 9 with the upper surface of its lower flange 12c (protrusion 12e in the figure), that is, the movable contact 9a pushes up the lower surface of the upper sheet 7. The fixed contact 7a is in contact and conduction state. On the other hand, the upper flange 12a is at a position where the upper sheet 3 is placed in a non-pressed state. In this way, the membrane switch S1 of both make and break contact type is constructed. Note that the above-mentioned contacts 3a, 5a, 7a, and 9a are not limited to an annular shape, and various shapes can be considered. Further, the shape of the pusher 12 can also be formed by dividing the shaft portion into an upper pusher and a lower pusher. Further, the reversing spring 13 is not limited to a dome-shaped spring (disc spring), but may be any other material that provides a click feeling when the switch is operated, such as a leaf spring having a substantially Ω-shaped cross section.

(e) Effect With the above-described configuration, when the key operation portion of the top sheet 1 is pressed downward with a finger, the pusher 12 located below the key operation is pushed down. At this time, the reversing spring 13 located below the pusher 12
The top portion 13a is pushed down and reversed into a concave state by a snap operation. Since this inverted state is transmitted to the operator's fingers, the operator feels a click when operating the switch. Reversal spring 13
When the pusher 12 is reversed to a concave state, the pusher 12
Since the upper flange 12a is also lowered, the upper flange 12a
pushes the upper sheet 3 down toward the lower sheet 5 with its lower surface (protrusion 12d in the figure),
That is, the movable contact 3a is electrically connected to the fixed contact 5a. On the other hand, the lower flange 12b is released from the state in which it was pressing the lower sheet 9 toward the upper sheet 7 with its upper surface (protrusion 12e in the figure), so the lower sheet 9 separates from the upper sheet 7 due to its elasticity. In other words, the movable contact 9a is separated from the fixed contact 7a, and the contact is no longer electrically conductive.

Next, when you release your finger from the key operation part of the top sheet 1, the reversing spring 13 snaps and reverses from the concave state to the original convex state.
2 rises, and the upper sheet 3, which had been pressed by its upper flange 12a, separates from the lower sheet 5 due to its elasticity, turning off the contact signal, and one lower flange 12
c presses the lower sheet 9 toward the upper sheet 7 again to turn on the contact signal.

(f) Embodiment FIG. 2 is a schematic sectional view of a contact portion showing another embodiment of this invention.

The structure of the membrane switch S2 in this embodiment is almost the same as the structure of the make and break contact system explained in FIG. The difference is that it is divided into a pusher 22A and a lower pusher 22B having a lower flange 22c, but this is a manufacturing problem and does not change its function in any way. Further, by using the printed circuit board 21 as the base material, contacts 21a and 21b are formed below the reversal spring 13, and when the reversal spring 13 is reversed, the contacts 21a and 21b are connected to each other via the reversal spring 13 made of this copper alloy plated with silver. Contact point 21
a and 21b are brought into bridging conduction so that an auxiliary contact signal can be output. Furthermore, a thin EL (electroluminescent) lamp 23 is incorporated into the through hole 2a of the spacer sheet 2 as a lighting element that can be driven by this auxiliary contact signal. Therefore, the upper pusher 22A and the lower pusher 22
When B is pressed and lowered, the reversal spring 13 is reversed to a concave state, turning on the make contact and turning off the break contact, as well as turning on the auxiliary contacts 21a and 21.
EL lamp 23 is made conductive between B and this contact signal.
This makes it possible to turn on the light, making it possible to construct an illuminated make and break contact type membrane switch in a thin shape. Of course, it is also possible to configure the auxiliary contact signal to be output to the outside.

(g) Effects of the invention Since this invention is configured as described above, it is possible to construct a thin membrane switch that is equipped with both make contacts and break contacts, and can be used as a keyboard switch, etc. It is also very effective.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a contact part of a membrane switch according to this invention, Fig. 2 is a schematic sectional view of a contact part showing another embodiment, and Fig. 3 is a schematic sectional view of a contact part showing a conventional example. It is a diagram. 3... Upper layer sheet, 3a... Movable contact, 4...
Spacer sheet, 5... lower layer sheet, 5a... fixed contact, 6... spacer base material, 7... upper layer sheet, 7a... fixed contact, 8... spacer sheet,
9... lower layer sheet, 9a... movable contact, 12...
Pusher, 12a... Upper collar part, 12b... Shaft part,
12c...Lower flange, 13...Reversal spring.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A first upper sheet and a first upper layer sheet each having a movable contact and a fixed contact constituting a make contact portion formed in opposing parts on the surfaces of two flexible wiring sheets.
A lower layer sheet is laminated with a first spacer sheet that can maintain a predetermined distance between the two contacts, and a fixed contact forming a break contact portion and a movable contact are formed at opposing positions on the surfaces of the two flexible wiring sheets. A second upper layer sheet and a second lower layer sheet, which are laminated with a second spacer sheet forming contact points and capable of maintaining a predetermined distance between the two contact points, are placed below the first lower layer sheet through a spacer base material. further comprising a shaft portion inserted into a space near the make contact portion and the break contact portion, and an upper flange portion formed at an upper periphery of the shaft portion on the upper surface of the first upper layer sheet. A pusher element that can be brought into contact and whose lower flange part formed on the lower peripheral edge of the shaft part can be brought into contact with the lower surface of the second lower layer sheet is inserted, and further below the shaft of the pusher element. 1. A membrane switch characterized in that a reversal spring is inserted on one base material, and the pusher is pressed upward by the reversal spring. (2) The membrane switch according to claim 1, wherein the pusher has an upper flange portion and a lower flange portion integrally formed on a shaft portion. (3) The membrane switch according to claim 1, wherein the pusher is divided into a shaft portion having an upper flange portion and a shaft portion having a lower flange portion. (4) The membrane switch according to any one of claims 1 to 3, wherein the reversing spring is a dome-shaped spring. (5) The membrane switch according to any one of claims 1 to 3, wherein the reversing spring is a plate spring having a substantially Ω-shaped cross section.