JPH0424579Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a keyboard switch used in electrical equipment and the like.

[Conventional technology]

An example of a conventional keyboard switch (hereinafter referred to as a switch) is shown in FIG. 3a. That is, an insulating spacer 12 having a plurality of through holes 12a is fixed between the surfaces of the flexible sheet 11 that are bent to face each other, and the opposing surface of the flexible sheet 11 faces the through holes 12a of the spacer 12. A fixed contact 11a and a movable contact 11b are arranged facing each other. and fixed contact 1
The switch portion 13a is formed by folding the pattern drawing sheet 11d continuous from the fixed contact side sheet 11c on which the contact point 1a is formed and overlapping the movable contact side sheet 11e.

A spring member 14 is disposed on the switch portion 13a, and a key top 15 is placed on the spring member 14 and accommodated between an insulator 16 and a metal bottom plate 17 to form the switch 1a. The switch 1a is operated by pressing the key top 15 with a finger, and the pattern drawing sheet 11d and the movable contact side sheet 11e are connected via the spring member 14.
Press and deform the movable contact 11b into the fixed contact 11a.
A switch operation is performed by touching the switch.

[Problem that the invention attempts to solve]

However, in the above structure, since the pattern drawer sheet 11d is interposed between the spring member 14 and the movable contact side sheet 11e, the pressing operation force of the key top 15 when performing a switch operation is equivalent to the amount that deforms the pattern drawer sheet 11d. will be increased by an additional amount. Furthermore, in order to obtain a good switching operation, it is necessary to maintain an appropriate distance between the fixed contact 11a and the movable contact 11b.
In the structure in which the pattern drawing sheet 11d is interposed between the movable contact side sheet 11e and the sheet 11e on the movable contact side, the sheet itself is subject to deflection and distortion due to the external environment such as temperature, so it is necessary to properly maintain the gap between the contacts. This made it difficult to maintain the reliability of the switching operation. There is also a switch 1b shown in FIG. 3b in which a pattern drawing sheet 11d following a movable contact sheet 11e is folded back onto the lower surface of a fixed contact sheet 11c to form an overlapping switch portion 13b. In this case, by pressing the key top 15, the movable contact side sheet 11e can be directly pressed and deformed via the spring member 14. However, in this switch 1b as well, since the pattern drawing sheet 11d is interposed between the fixed contact side sheet 11c and the bottom plate 17, the fixed contact side sheet 11c may be bent or distorted due to the external environment. As a result, proper clearance between the contacts could not be achieved and the reliability of the switching operation was compromised.

The present invention has been devised to eliminate such drawbacks, and an object of the present invention is to provide a keyboard switch whose switching characteristics are not impaired by the pattern drawing sheet and whose ease of assembly is improved.

[Means for solving problems]

According to this invention, a spacer having a through hole is clamped and fixed between flexible sheets that are bent to face each other, and a movable contact and a fixed contact are arranged facing each other on the opposite plate surface of the flexible sheet facing the through hole. The pattern drawer sheet extending from the flexible sheet is folded back and superimposed on the movable contact side sheet, and a spring member having a dome portion is arranged on the movable contact side, and a key top placed on the dome portion is placed on the movable contact side. In a keyboard switch that connects and separates the contacts by pressing, a pattern drawer sheet that is continuous with the movable contact side sheet and has a hole through which the dome is inserted is arranged on the movable contact side sheet. The spring member is folded back toward the member side, and the hole is inserted into the dome portion, and the spring member is disposed on the spring member. In this way, the pattern drawer sheet is disposed on the spring member, and since a hole is provided in the portion of the pattern drawer sheet corresponding to the dome portion of the spring member, through which the dome portion is inserted, the switching operation is performed through the hole. It is done. Therefore, it is possible to obtain a keyboard switch whose switching characteristics are not impaired by the pattern drawing sheet and which is easy to assemble.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. The switch 2 includes a spacer 22 and a spring member 23 held between a flexible sheet 21.
and on the switch part 25 consisting of the plate 24,
A key top 26 is placed thereon and housed between an insulator 27 and a bottom plate 28.

To construct the switch portion 25, an insulating spacer 22 made of, for example, polyester and having a plurality of circular holes 22a is inserted between the surfaces of the flexible sheet 21 that are folded to face each other. A fixed contact 21 is placed on the opposite plate surface of the flexible sheet 21 facing the through hole 22a of the spacer 22.
The spacer 22 is fixed between the flexible sheets 21 by means of adhesive or the like, with the movable contacts 21b and 21b facing each other. Next, a dome portion 23a is placed on the movable contact side sheet 21c on which the movable contact 21b is formed.
and a flat part 23b, and the spring member 23 made of a thin sheet metal material having spring properties is attached to the dome part 2.
3a is disposed behind the movable contact 21b, and a plate 24 is fixed onto the flat portion 23b of the spring member 23 by means of adhesive or the like. plate 2
Reference numeral 4 is made of an insulating sheet made of polyester material, for example, and at a position corresponding to the dome portion 23a of the spring member 23 of the plate 24,
A hole 24a having a diameter D larger than the diameter d of the dome portion 23a is formed. Therefore, the plate 24 is disposed on the spring member 23 with the dome portion 23a projecting upward from the hole 24a.

Next, the pattern drawing sheet 21d, which is continuous from the movable contact side sheet 21c, is folded back toward the plate 24, superimposed on the plate 24, and fixed by adhesive or other means. A hole 21e having a diameter substantially equal to the diameter of the hole 24a is formed in the folded pattern drawing sheet 21d at a position corresponding to the hole 24a of the plate 24. For this purpose, the spring member 23 is installed in the switch section 25 in advance, as shown in the plan view of FIG. 2, with the top portion of the dome section 23a slightly protruding through the hole 21e. The switch portion 25 is clamped and fixed between the insulator 27 and the bottom plate 28 with the key top 26 placed on the dome portion 23a.

The insulator 27 is made of, for example, a synthetic resin material such as ABS, and has a recess 27a opening in its lower surface for accommodating the switch part 25. This recess 27
A hole 27c is provided through the bottom surface 27b of the switch part 25 at a position corresponding to the dome part 23a of the switch part 25. Therefore, to assemble the switch 2, the key top 26 is first inserted into the hole 27c of the insulator 27. The key top 26 has a flange 26a provided on its peripheral surface and a stepped portion 27d formed on the inner periphery of the hole 27c.
Due to the engagement with the hole 27c, it does not come out of the hole 27c. Next, the switch part 25 is inserted into the recess 27 of the insulator 27.
a, insert the dome part 23a into the key top 2
The lead-out part 21f extending from the pattern lead-out sheet 21d of the switch part 25 is made to correspond to the projection part 26b formed at the lower end of the switch part 25, and the lead-out part 21f is made to correspond to the projection part 26b formed at the lower end of the switch part 25.
It is pulled out through a hole 27e formed in the side wall of. Thereafter, a metal bottom plate 28 that closes the recess 27a is locked and fixed to the bottom surface of the insulator 27. Therefore, the switch section 25 is connected to the pattern drawer sheet 21d.
is in contact with the bottom surface 27b of the recess 27a, and the fixed contact side sheet 21g is in contact with the bottom plate 28, and is clamped and fixed within the recess 27a. Note that the key top 26 is held in the hole 27 by bringing the protrusion 26b into contact with the top of the dome portion 23a, and being pushed upward by the dome portion 23a.

In the switch 2 having the above structure, when the key top 26 is not pressed, the movable contact side sheet 21c is stretched to a flat state, so that the movable contact 21b and the fixed contact 21a are separated from each other. Next, key top 26
When the upper end of the dome portion 23a is pressed with a finger or the like, the direction of curvature of the dome portion 23a pressed by the projection portion 26b of the key top 26 is instantaneously reversed, as shown in FIG. 1B. Therefore, the portion of the movable contact side sheet 21c corresponding to the movable contact 21b is pressed by the dome portion 23a, and is elastically deformed inwardly along the periphery of the through hole 22a of the spacer 22. Then, the movable contact 21b contacts the fixed contact 21a, and the switch 2
is closed. After that, when the pressing force applied to the key top 26 is released, the dome portion 23a and the movable contact side sheet 21c are restored, and the key top 26 is returned to its original position, thereby separating the movable contact 21b and the fixed contact 21a and turning the switch off. 2 is in the off state.

[Effect of idea]

As explained above with reference to the embodiments, the switch of the present invention has a pattern drawer sheet placed above a spring member and overlapped, and a hole provided in the pattern drawer sheet at a position corresponding to the dome portion of the spring member. It is structured as follows. Therefore, since the switching operation is performed through the hole, the switching characteristics are not impaired by the pattern pull-out sheet.
Reliability can be improved. Furthermore, since the spring member is already assembled in the switch portion, there is no need to incorporate the spring member itself into the insulator, which improves assembly efficiency and provides an inexpensive switch.

[Brief explanation of drawings]

FIG. 1a is a cross-sectional view showing an embodiment of the present invention, FIG. 1b is a cross-sectional view showing the key top in a pressed state, and FIG.
FIGS. 3a and 3b are sectional views showing a conventional switch. 1a, 1b, 2...Keyboard switch, 1
1, 21...Flexible sheet, 11a, 21
a... Fixed contact, 11b, 21b... Movable contact,
11c, 21g...Fixed contact side sheet, 11d,
21d...Pattern drawer sheet, 11e, 21
c...Movable contact side sheet, 12, 22...Spacer, 12a, 22a...Through hole, 14, 23...Spring member, 15, 26...Key top.

Claims (1)

[Scope of utility model registration request] A spacer having a through hole is clamped and fixed between flexible sheets that are bent so as to face each other, and a movable contact and a fixed contact are arranged facing each other on the opposite plate surface of the flexible sheet facing the through hole,
A pattern drawing sheet extending from the flexible sheet is folded back and superimposed on the movable contact side sheet, and a spring member having a dome portion is placed on the movable contact side, and a key top placed on the dome portion is pressed. In the keyboard switch that connects and disconnects the contacts, a pattern pull-out sheet that is continuous with the movable contact side sheet and has a hole through which the dome is inserted is folded back to the spring member side that is arranged on the movable contact side sheet. In addition, the keyboard switch is characterized in that the hole is fitted into the dome portion and disposed on the spring member.