JPH0548160U - Membrane switch - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent damage to the insulation sheet, etc., due to repeated undulations of the movable push plate of the membrane switch. A folding portion 27 is provided on the outer periphery of a hemispherical metal movable push plate 17, and an outer peripheral edge of the movable push plate 17 is fixed upward.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a membrane switch, and more particularly to a membrane switch provided with a movable push plate made of a hemispherical metal.

[0002]

[Prior Art]

 A conventional membrane switch of this type is shown in FIG. A spacer 3 is interposed between an upper film 1 and a lower film 2 of polyester or the like, and a gap portion 4 is provided, and contacts 5 and 6 are provided to face the gap portion 4. A movable pressing plate 7 made of a hemispherical metal is provided on the outer side of the upper film 1, and an insulating sheet 8 is attached and fixed so that the movable pressing plate 7 is not displaced. Further, a key top 9 is provided above the movable push plate 7 so as to be movable up and down, and by pressing the key top 9, the insulating sheet 8 and the movable push plate 7 are pressed downward, and the contact 5 of the upper film 1 and the bottom It is configured to make contact with the contact 6 of the film 2.

[0003]

[Problems to be solved by the device]

 In the conventional membrane switch described above, the movable push plate 7 is fixed by the insulating sheet 8. However, when the key top 9 is moved downward and the insulating sheet 8 and the movable push plate 7 are pressed, the movable push plate 7 is moved. It becomes concave, and its outer peripheral edge 7a bends upward. When the key top 9 is moved upward, the movable push plate 7 and the insulating sheet 8 are restored to their original shapes due to the repulsion of the movable push plate 7. When such an operation is repeated, when the movable pressing plate 7 is pressed, first, the outer peripheral edge 7a comes into strong contact with the upper film 1, and the contact portion of the upper film 1 is easily damaged. When the movable push plate 7 is pressed and becomes concave, the outer peripheral edge 7a thereof is turned up and strongly contacts the insulating sheet 8, and the contact portion of the insulating sheet 8 is easily damaged.

Therefore, there arises a technical problem to be solved in order to endure the concavo-convex movement of the movable push plate and prevent the upper film and the insulating sheet from being damaged, and the present invention solves this problem. The purpose is to

[0005]

[Means for Solving the Problems]

 This invention has been proposed in order to achieve the above-mentioned object, and a contact is made to face each other by providing a gap between films of polyester or the like, and a hemispherical metal movable pusher is provided on the outside of the film on one side of the contact part. In a membrane switch in which a plate is provided, an insulating sheet is attached and the movable push plate is fixed, and the movable push plate portion can be tapped with a key top, a folded portion is provided on the outer periphery of the movable push plate. The present invention provides a membrane switch characterized in that the outer peripheral edge of a movable push plate is formed upward.

[0006]

[Action]

 In this invention, since the upward folding portion is provided on the outer peripheral edge of the movable pressing plate, when the movable pushing plate is pressed by the downward movement of the key top, first, the lower surface of the folding portion becomes the upper film. When the movable pushing plate is pressed to be deformed into a concave shape, the upper surface of the folded portion comes into contact with the insulating sheet at an obtuse angle.

Therefore, even if the vertical movement of the key top is repeated, there is no possibility that the outer peripheral edge of the movable pressing plate will damage the insulating sheet or the upper film.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. For convenience of description, the same components as those of the related art will be described at the same time. 1 and 2 show a membrane switch according to an embodiment of the present invention, in which a spacer 13 is interposed between an upper film 11 made of polyester or the like and a lower film 12 to form a gap portion 14. The contacts 15 and 16 are provided facing each other in the gap 14. A movable pressing plate 17 made of a hemispherical metal is provided on the outer side of the upper portion of the upper film 11, and an adhesive portion 19 of an insulating sheet 18 is attached.

Opening portions 20, 20 exposing both sides of the movable push plate 17 are provided facing the movable push plate 17 of the insulating sheet 18. The adhesive portion 19a of the strip-shaped portion 21 between the openings 20 and 20 adheres from one side of the central portion of the movable push plate 17 to the other and covers the central portion of the movable push plate 17. , The movable push plate 17 is prevented from moving and fixed.

Although not shown, an opening is formed so that the central portion of the movable push plate 17 is exposed, and both side portions of the movable push plate 17 are adhered by the adhesive portions 19 of the insulating sheet 18 so that the movable push plate 17 can be moved. It may be fixed so as to prevent the push plate 17 from moving. Here, the contacts 15 and 16 are formed of silver electrodes, respectively, and the periphery thereof is covered with carbons 22 and 23 to prevent oxidation. Further, the contacts 15 and 16 are connected to other circuits by wiring patterns 24 and 25.

A key top 26 is provided above the strip-shaped portion 21 of the insulating sheet 18 so as to be movable up and down, and when the key top 26 is pressed, the lower end surface 26a of the key top is lowered, and the strip shape of the insulating sheet 18 is formed. The central portion of the portion 21 and the movable push plate 17 is pushed down. Therefore, the central portion of the movable push plate 17 presses the upper film 11, and the contact point 15 of the upper film 11 and the contact point 16 of the lower film 12 come into contact with each other. When the key top 26 is moved upward, the repulsive force of the movable push plate 17 restores the movable push plate 17 and the insulating sheet 18 to their original shapes, and the contact point 15 of the upper film 11 and the contact point 16 of the lower film 12 are also separated. To do.

Thus, the folded-back portion 27 is provided on the outer peripheral edge of the movable push plate 17, and the outer peripheral edge of the movable push plate 17 is formed upward. When the movable push plate 17 is pressed by the downward movement of the key top 26, first, the lower surface of the folded portion 27 contacts the upper film 11 at an obtuse angle, and further, the movable push plate 17 is pressed to form a recess. When deformed into a shape, the upper surface of the folded portion 27 contacts the insulating sheet 18 at an obtuse angle.

Therefore, even if the concavo-convex action of the movable push plate 17 is repeated, damage to the upper film 11 and the insulating sheet 18 can be reduced. Naturally, the folded-back portion 27 is also effective for a structure in which the entire surface of the movable pressing plate 17 is covered with the conventional insulating sheet. Also, although not shown, if a concave portion is provided at the center position of the movable push plate 17, the upper film 11 can be pressed more strongly when the movable push plate 17 is pressed, and the contacts 15 and 16 can be favorably contacted. .

3 and 4 show another embodiment of the present invention, in which an opening hole 28 is opened at a portion of the strip-shaped portion 21 of the insulating sheet 18 where the lower end surface 26a of the key top abuts. In such a case, when the key top 26 is tapped, the lower end surface 26a of the key top does not contact the insulating sheet 18 and directly presses the movable push plate 17. Therefore, there is no possibility that the insulating sheet 18 deteriorates and the band-like portion 21 is cracked or split. It should be noted that the present invention can be modified in various ways without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified version.

[0015]

[Effect of the device]

 Since the present invention is configured as described in detail in the above embodiment, it becomes easy to fix the movable push plate, and it is necessary to perform special air bleeding when attaching the movable push plate or to attach a separate adhesive tape. There is no. Therefore, the number of parts is reduced to reduce the cost and the workability at the time of assembly can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a membrane switch showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a main part of a membrane switch showing another embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a vertical cross-sectional view of a conventional membrane switch.

[Explanation of symbols]

 11 Upper Film 12 Lower Film 13 Spacer 14 Gap 15, 16 Contact 17 Movable Push Plate 18 Insulation Sheet 26 Key Top 27 Folding Part

Continuation of front page (72) Creator Tsutomu Tomita 1-11-30 Niihara, Mito City, Ibaraki Prefecture

Claims (1)

[Scope of utility model registration request] 1. A movable pressing plate made of a hemispherical metal is provided outside a film on one side of the contact portion with a gap provided between films of polyester or the like, and an insulating sheet is attached to the movable pressing plate. In a membrane switch in which a plate is fixed and a movable push plate part can be tapped with a key top, a folding portion is provided on the outer periphery of the movable push plate, and an outer peripheral edge of the movable push plate is formed upward. Membrane switch.