JP2004031171A

JP2004031171A - Two-step push switch

Info

Publication number: JP2004031171A
Application number: JP2002186830A
Authority: JP
Inventors: Kazunori Yamada; 山田　和徳
Original assignee: SMK Corp
Current assignee: SMK Corp
Priority date: 2002-06-26
Filing date: 2002-06-26
Publication date: 2004-01-29

Abstract

<P>PROBLEM TO BE SOLVED: To lengthen the life of a two-step push switch and widen the variation of load characteristics as the two-step push switch by enhancing the flexibility in the load characteristics of a first step and that of a second step. <P>SOLUTION: A tact plate of the two-step push switch is formed with a first tact plate 5 and a second tact plate 6, the first tact plate 5 is elastically deformed by pressing a key top, a protrusion 56 is brought into contact with the second tact plate 6 by first step deformation to connect the first and second terminals 2, 3, a central part of the second tact plate 6 is brought into contact with a contact part 41 of a third terminal 4 by second step deformation to connect the first, second, and third terminals 2, 3, 4. The tact plate is formed with the first and second tact plates 5, 6 so as not to generate excess stress to lengthen the life, and the flexibility in the load characteristics of the first step and that of the second step is enhanced. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、カメラ、電子機器などに使用される２段動作プッシュスイッチに関するものである。例えばカメラのシャッターに使用される２段動作プッシュスイッチに関するものである。
【０００２】
【従来の技術】
従来の２段動作プッシュスイッチには、図１８〜図２４に示すようなものが知られている。すなわち、ハウジング１００にタクト板２００を収容するタクト板収容凹部１０１を形成し、ハウジング１００の底板に第１、第２、第３端子３０１、３０２、３０３を固着し、第１、第２、第３端子３０１、３０２、３０３の接触部（３１１，３１１）、（３１２，３１２）、（３１３）を、タクト板収容凹部１０１の内底面の外側周辺部、内側周辺部、中央部の位置において周囲の内底面より突出した状態で露出させ、第１、第２、第３端子３０１、３０２、３０３の接続部３２１，３２１、３２２、３２３をハウジング１００の外へ突出させる。タクト板収容凹部１０１の開口面をカバー４００で覆い、カバー４００の中央部に穿設されたキートップ用孔４０１からキートップ５００の操作部を外部へ突出させ、カバー４００の側面に形成された係止ばね部４０２〜４０２をハウジング１００の外側面に突設された係止突起１０３〜１０３に係止して、カバー４００をハウジング１００に固定する。
【０００３】
タクト板２００は、図２４に示すように、水平円板状の中央接触部２０１と、中央接触部２０１の外周側に半円弧孔２０２、２０２で隔てられるとともに連結部２０３、２０３で連結された環状部２０４と、環状部２０４の外周側の対向する位置に突設された水平矩形板状の周辺接触部２０５、２０５とを具備し、環状部２０４は外周側が下方へ傾斜した形状に形成され、環状部２０４の円周方向に沿って等間隔に、中心角度で９０°の位置に絞り部２０６〜２０６が形成されている。
タクト板２００は、初期状態では、図２２に示すように、ハウジング１００の底板内面とキートップ５００の下面との間に若干弾性変形した状態でタクト板収容凹部１０１内に収容され、周辺接触部２０５、２０５が第１端子３０１の接触部３１１、３１１に接触している。
【０００４】
そして、キートップ５００を押し下げると、キートップ５００の押圧突起がタクト板２００の中央接触部２０１を押し込んで環状部２０４を反転させる。この変形を１段目の変形とすると、この変形によって中央接触部２０１の周辺部が第２端子３０２の接触部３１２、３１２に接触し、第１、第２端子３０１、３０２間を電気的に接続する。
ついで、キートップ５００をさらに押し下げると、キートップ５００の押圧突起がタクト板２００の中央接触部２０１をさらに押し込んで変形が進む。この変形を２段目の変形とすると、この変形によって中央接触部２０１の中心部が第３端子３０３の接触部３１３に接触し、第１、第２、第３端子３０１、３０２、３０３間を電気的に接続する。
【０００５】
【発明が解決しようとする課題】
しかしながら、図１８〜図２４に示した従来例では、１つのタクト板２００で２段階の接続を行っていたので、タクト板２００の連結部２０３、２０３に過度のストレス（応力）がかかり、少ない動作回数でタクト板２００が破損するという問題点があった。
例えば、タクト板２００の１段目の変形では、曲げ加工で形成された環状部２０４が反転し、タクト板２００の２段目の変形では、絞り加工で形成された中央接触部２０１が反転するので、両者の境目の連結部２０３、２０３に応力集中で割れが生じ易いという問題点があった。
また、１つのタクト板２００で２段階の接続を行っていたので、１段目の荷重特性と２段目の荷重特性の自由度が小さく、荷重特性のバリエーションを広げることができないという問題点があった。
例えば、１段目の荷重特性を所望の特性に合わせたときに、その影響が２段目の荷重特性に及ぶため、２段目の荷重特性の自由度が小さく、所望の特性が得にくいという問題点があった。
【０００６】
本発明は、上述の問題点を鑑みなされたもので、長寿命化を図ることができるとともに、１段目の荷重特性と２段目の荷重特性の自由度を大きくして、荷重特性のバリエーションを広げることのできる２段動作プッシュスイッチを提供することを目的とするものである。
【０００７】
【課題を解決するための手段】
請求項１に記載の発明は、ハウジング（１）にタクト板を収容するタクト板収容凹部（１３）を形成し、ハウジング（１）に固定した第１、第２、第３端子（２）、（３）、（４）の接触部（２１，２１）、（３１，３１）、（４１）をタクト板収容凹部（１３）の内底面の外側周辺部、内側周辺部、中央部に露出させ、キートップ（７）の押圧でタクト板を弾性変形させることによって、接触部（２１，２１）、（３１，３１）との接触による第１、第２端子（２）、（３）間の接続と、接触部（２１，２１）、（３１，３１）、（４１）との接触による第１、第２、第３端子（２）、（３）、（４）間の接続との２段階の接続をする２段動作プッシュスイッチであって、前記タクト板をタクト板収容凹部（１３）内で上下に離して配置された第１、第２タクト板（５）、（６）で形成し、第１タクト板（５）は、周辺部を第１端子（２）の接触部（２１，２１）に接触させるとともに、中央部の下面に凸部（５６）を形成し、第２タクト板（６）は、中央部を上方に膨出して周辺部を第２端子（３）の接触部（３１，３１）に接触させ、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させ、１段目の変形で凸部（５６）を第２タクト板（６）に接触させ、２段目の変形で第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させることを特徴とするものである。
【０００８】
上述の構成において、タクト板を第１、第２タクト板（５）、（６）で形成し、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させる。第１タクト板（５）の１段目の変形で凸部（５６）を第２タクト板（６）に接触させて第１、第２端子（２）、（３）間を電気的に接続し、第１タクト板（５）の２段目の変形で第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させて第１、第２、第３端子（２）、（３）、（４）間を電気的に接続する。　タクト板を第１、第２タクト板（５）、（６）の２つとし、第１、第２タクト板（５）、（６）のそれぞれに過度のストレスが生じないようにするとともに、１段目の荷重特性と２段目の荷重特性の自由度を大きくすることができる。
【０００９】
請求項２に記載の発明は、ハウジング（１）にタクト板を収容するタクト板収容凹部（１３）を形成し、ハウジング（１）に固定した第１、第２、第３端子（２）、（３）、（４）の接触部（２１，２１）、（３１，３１）、（４１）をタクト板収容凹部（１３）の内底面の外側周辺部、内側周辺部、中央部に露出させ、キートップ（７）の押圧でタクト板を弾性変形させることによって、接触部（２１，２１）、（３１，３１）との接触による第１、第２端子（２）、（３）間の接続と、接触部（２１，２１）、（３１，３１）、（４１）との接触による第１、第２、第３端子（２）、（３）、（４）間の接続との２段階の接続をする２段動作プッシュスイッチであって、前記タクト板をタクト板収容凹部（１３）内で上下に離して配置された第１、第２タクト板（５）、（６）で形成し、第１タクト板（５）は、周辺部を第１端子（２）の接触部（２１，２１）の上方に配置するとともに、中央部の下面に凸部（５６）を形成し、第２タクト板（６）は、中央部を上方に膨出して周辺部を第２端子（３）の接触部（３１，３１）の上方に配置し、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させ、１段目の変形で第１タクト板（５）の周辺部を第１端子（２）の接触部（２１，２１）に接触させるとともに、凸部（５６）が第２タクト板（６）に押圧接触して第２タクト板（６）の周辺部を第２端子（３）の接触部（３１，３１）に接触させ、２段目の変形で第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させることを特徴とするものである。
【００１０】
上述の構成において、タクト板を第１、第２タクト板（５）、（６）で形成し、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させる。第１タクト板（５）の１段目の変形で、第１タクト板（５）の周辺部を第１端子（２）の接触部（２１，２１）に接触させるとともに、凸部（５６）が第２タクト板（６）に押圧接触して第２タクト板（６）の周辺部を第２端子（３）の接触部（３１，３１）に接触させることによって、第１、第２端子（２）、（３）間を電気的に接続する。第１タクト板（５）の２段目の変形で、第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させることによって、第１、第２、第３端子（２）、（３）、（４）間を電気的に接続する。
タクト板を第１、第２タクト板（５）、（６）の２つとし、第１、第２タクト板（５）、（６）のそれぞれに過度のストレスが生じないようにするとともに、１段目の荷重特性と２段目の荷重特性の自由度を大きくすることができる。
【００１１】
請求項３に記載の発明は、請求項１又は２に記載の発明において、クリック感を生じさせるために、第１タクト板（５）を、ほぼ水平板状の中央接触部（５１）と、中央接触部（５１）の外周側にほぼ半円状の孔（５２，５２）で隔てられとともに連結部（５３，５３）で連結された環状部（５４）と、環状部（５４）の外周側の対向する位置に突設されて第１端子（２）の接触部（２１，２１）に接触するほぼ水平矩形板状の周辺接触部（５５，５５）とで形成し、環状部（５４）は外周側が下方へ傾斜した形状に形成され、環状部（５４）に絞り部（５８〜５８）を形成したことを特徴とするものである。
【００１２】
請求項４に記載の発明は、請求項３に記載の発明において、キートップ（７）からの荷重を損失させることなく第１タクト板（５）の絞り部（５８〜５８）に伝達するために、第１タクト板（５）の中央接触部（５１）を、連結部（５３，５３）と連結する方向を長手方向としたほぼ長方形状に形成し、中央接触部（５１）の長手方向の端縁に連設される立ち上げ片（５７，５７）と、中央接触部（５１）の板面の長手方向に沿って形成されるビード（５７ｂ，５７ｂ）とのうちの少なくとも一方を、中央接触部（５１）の補強用として設けたことを特徴とするものである。
【００１３】
請求項５に記載の発明は、請求項３に記載の発明において、キートップ（７）からの荷重を損失させることなく第１タクト板（５）の絞り部（５８〜５８）に伝達するために、第１タクト板（５）の中央接触部（５１）を、連結部（５３，５３）と連結する方向を長手方向としたほぼ長方形状に形成し、中央接触部（５１）の長手方向の端縁に連設される折り返し片（５７ａ，５７ａ）と、中央接触部（５１）の板面の長手方向に沿って形成されるビード（５７ｂ，５７ｂ）とのうちの少なくとも一方を、中央接触部（５１）の補強用として設けたことを特徴とするものである。
【００１４】
請求項６の記載の発明は、請求項１、２、３、４又は５に記載の発明において、第２タクト板（６）がタクト板収容凹部（１３）の所定位置からずれるのを防止するために、タクト板収容凹部（１３）の内底面の第２タクト板（６）の周辺部に隣設する部分に、タクト板収容凹部（１３）の周辺部をほぼ固定するための加締め部（１７〜１７）を形成したことを特徴とするものである。
【００１５】
【発明の実施の形態】
以下、本発明の一実施形態例を図１〜図１５を用いて説明する。
図１〜図３は全体の構成を示すもので、これらの図において、１はハウジング、２、３、４は第１、第２、第３端子、５は第１タクト板、６は第２タクト板、７はキートップ、８はカバーである。
【００１６】
ハウジング１は、図４〜図９に示すように、矩形状の底板１１と、この底板１１の外周辺から一体に直立して包囲する側板１２とを具備し、底板１１と側板１２によって上面を開口したタクト板収容凹部１３が形成されている。
タクト板収容凹部１３の対向する内側面には、第１タクト板５の周辺接触部５５、５５（後述する）を位置合わせして収容する位置合わせ用凹部１４、１４が形成されている。
タクト板収容凹部１３の内底面は、円形状の中央部と、この中央部の周辺に連続する環状の内側周辺部と、この内側周辺部の外周辺に連続する外側周辺部とを具備し、表面の高さが図７に示すように階段状に順次高くなるように形成されている。
位置合わせ用凹部１４、１４の内底面は、タクト板収容凹部１３の内底面の外側周辺部の一部となり、同一高さに形成されている。
タクト板収容凹部１３の内底面の内側周辺部には、第２タクト板６の周辺部を位置合わせして収容する弧状の加締め用突起１５〜１５が突設されている。
ハウジング１の側板１２の外側面には、カバー８を係止する係止突起１６〜１６が形成されている。
【００１７】
ハウジング１の底板１１には、第１、第２、第３端子２、３、４がハウジング１の成型時に一体に設けられている。例えば、導電性金属板のプレス成形で図１０（ａ）、（ｂ）に示すような第１、第２、第３端子２、３、４を形成して金型内に配置し、樹脂の注入、固化によって一体成型される。
このとき、第１端子２の接触部２１、２１は、タクト板収容凹部１３の内底面の外側周辺部のうちの位置合わせ用凹部１４、１４の内底面において、周囲の内底面から突出した状態で露出し、第１端子２の接続部２２、２２はハウジング１の外に突出している。
また、第２端子３の接触部３１、３１は、タクト板収容凹部１３の内底面の内側周辺部であって第２タクト板６の周辺接触部と接触可能な位置において、周囲の内底面から突出した状態で露出し、第２端子３の接続部３２はハウジング１の外に突出している。
また、第３端子４の接触部４１は、タクト板収容凹部１３の内底面の中央部の中心位置において、周囲の内底面から突出した状態で露出し、第３端子４の接続部４２はハウジング１の外に突出している。
【００１８】
第１タクト板５は、弾性を有する厚さｔ（例えばｔ＝０．０６ｍｍ）の導電性金属板の打ち抜き、折り曲げ加工で形成されて、タクト板収容凹部１３内に収容されるもので、図１１〜図１３に示すように、水平なほぼ長方形板状の中央接触部５１と、中央接触部５１の外周側にほぼ半円状の孔５２、５２で隔てられるとともに帯状の連結部５３、５３で連結された環状部５４と、環状部５４の外周側の対向する位置に突設された水平な矩形板状の周辺接触部５５、５５とで形成されている。
中央接触部５１の中央部には、下方へ膨出した凸部５６が形成され、中央接触部５１の長手方向の端縁には、上方へ折り曲げた立ち上げ片５７，５７が形成されている。
環状部５４には、円周方向に沿って等間隔に、中心角９０°の位置に、上方へ膨出した絞り部５８〜５８が形成されている。
【００１９】
第２タクト板６は、弾性を有する厚さｔ（例えばｔ＝０．０４ｍｍ）の導電性金属板を打ち抜き、絞り加工することによって形成したものを、タクト板収容凹部１３内に２枚重ねて収容されるもので、図１に示すように、中央部を上方へ膨出した円板状（すなわちドーム状）に形成されている。
【００２０】
キートップ７は、第１タクト板５を押圧して２段階に弾性変形させるためのもので、図１４に示すように、円柱状の操作部７１と、操作部７１の下部に一体に連設されたほぼ円板状の押圧部７２と、押圧部７２の対向する外周側に一体に突設されて先端部がハウジング１の位置合わせ用凹部１４、１４に係合するほぼ矩形状の位置合わせ部７３、７３とからなり、押圧部７２の下面には第１タクト板５の立ち上げ片５７、５７を収容する収容凹部７４、７４が形成されている。
【００２１】
カバー８は、タクト板収容凹部１３の開口部を覆ってハウジング１に固着されるもので、図１５に示すように、外縁がハウジング１の外縁とほぼ同一の矩形状に形成され、中央部には、キートップ７の操作部７１を上下動可能に突出するためのキートップ用孔８１が形成され、外周部には、ハウジング１の係止突起１６〜１６に圧入して係止する係止ばね部８２〜８２が形成されている。
【００２２】
つぎに、以上のように構成された２段動作プッシュスイッチの組み立てについて説明する。
（１）ハウジング１の成型時において、ハウジング１の底板１１には、図４〜図９に示すように、第１、第２、第３端子２、３、４が一体成型で形成されている。
【００２３】
（２）ハウジング１のタクト板収容凹部１３内の所定位置に第２タクト板６を載置し、加締め用突起１５〜１５を加熱し、図９に矢印で示すように内側へ折り曲げ変形して、図１（ｂ）に示すような加締め部１７〜１７とし、第２タクト板６の周辺部をほぼ固定する。これによって、第２タクト板６の周辺部を第２端子３の接触部３１，３１に常時接触させた状態としている。
【００２４】
（３）ついで、ハウジング１のタクト板収容凹部１３内に第１タクト板５を位置合わせしつつ載置する。すなわち図４に示すように、第１タクト板５の周辺接触部５５、５５をハウジング１の位置合わせ用凹部１４、１４に位置合わせして第１タクト板５をタクト板収容凹部１３内に載置し、周辺接触部５５、５５を第１端子２の接触部２１、２１に接触させる。
【００２５】
（４）ついで、キートップ７の位置合わせ部７３、７３をハウジング１の位置合わせ用凹部１４、１４に位置合わせするとともに、キートップ７の収容凹部７４、７４に第１タクト板５の立ち上げ片５７、５７を収容しつつキートップ７を第１タクト板５上に載置し、その上からカバー８を被せてキートップ用孔８１から操作部７１を上部へ突出させ、カバー８の係止ばね部８２〜８２をハウジング１の係止突起１６〜１６に圧入して係止し、図１〜図３に示すように組み立てを完了する。
この組み立て完了状態では、第１タクト板５は、その中央接触部５１がキートップ７の押圧部７２に押圧されて若干弾性変形した状態でタクト板収容凹部１３内に収容され、図１に示すように第１タクト板５の周辺接触部５５、５５を第１端子２の接触部２１、２１に常時接触させた状態にしている。
【００２６】
（５）上述のようにして組み立てられた２段動作プッシュスイッチは、例えば、基板（図示省略）上の所定位置に位置合わせして載置した後、第１、第２、第３端子２、３、４の接続部２２，２２、３２、４２が基板上の配線パターンと半田接続される。
【００２７】
つぎに、前記実施形態例の作用を説明する。
（１）図１においてキートップ７を押し下げると、押圧部７２が第１タクト板５の中央接触部５１を押し込んで連結部５３、５３を反転させるとともに環状部５４を弾性変形させる。この変形を１段目の変形とすると、この変形によって第１タクト板５の凸部５６が第２タクト板６の中央部に接触し、第１、第２端子２、３間が電気的に接続する。
この１段目の変形では、連結部５３、５３を反転させるとともに、絞り部５８〜５８の形成された環状部５４を弾性変形させてクリック感を生じさせている。このとき、中央接触部５１の立ち上げ片５７、５７が中央接触部５１の強度を補強しているので、中央接触部５１の撓みによる荷重の損失を抑え、キートップ７からの荷重を損失させことなく絞り部５８〜５８に伝えてクリック感を生じさせることができる。
また、この１段目の変形では、キートップ７に加えられる荷重とストロークの関係を表す荷重特性は、第１タクト板５の形状や構造に依存する。このため、第１タクト板５の板厚や形状、絞り部５８〜５８の形状等を変えることによって荷重特性を変えることができる。
【００２８】
（２）ついで、キートップ７をさらに押し下げると、第１タクト板５の凸部５６が第２タクト板６の中央部を押し込んで第２タクト板６を反転させる。この変形を２段目の変形とすると、この変形によって第２タクト板６の中央部が第３端子４の接触部４１に接触し、第１、第２、第３端子２、３、４間が電気的に接続する。
この２段目の変形では、第２タクト板６を反転させてクリック感を生じさせている。
また、この２段目の変形では、キートップ７に加えられる荷重とストロークの関係を表す荷重特性は、主として第２タクト板６の形状や構造に依存する。このため、第２タクト板６の板厚や形状等を変えることによって荷重特性を変えることができる。
また、第２タクト板６の周辺部がハウジング１の加締め部１７〜１７によってハウジング１にほぼ固定されているので、２段動作プッシュスイッチの搬送時や２段動作プッシュスイッチのスイッチ動作時において第２タクト板６が所定位置からずれるのを防止することができる。このため、第２タクト板６の中央部を第３端子４の接触部４１に接触させたときに、第２タクト板６の周辺部が第２端子３の接触部３１、３１からずれて非接触となるような状態を防止できる。
【００２９】
（３）キートップ７への押圧を解除すると、第１、第２タクト板５、６の自らの復元力でキートップ７を押し上げ、第２タクト板６の中央部が第３端子４の接触部４１から離れるとともに、第１タクト板５の凸部５６が第２タクト板６から離れて電気的に非接続となり、図１の初期状態に戻る。
【００３０】
前記実施形態例では、第１タクト板５の中央部の上面をキートップ７の下面に当接させ、キートップ７の押圧で第１タクト板５を２段階に弾性変形させた場合について説明したが、本発明はこれに限るものでなく、第１タクト板５の中央部の上面とキートップ７の下面との間に間隙を設け、キートップ７の押圧でキートップ７が第１タクト板５に押圧接触することによって第１タクト板５を２段階に弾性変形させた場合についても利用することができる。
例えば、キートップ７の操作部７１の外周面に段部又は鍔部を形成し、この段部又は鍔部とカバー８の上面との間に弾性体を介在することによって、第１タクト板５の中央部の上面とキートップ７の下面との間に間隙を設け、キートップ７の押圧で弾性体を弾性変形してキートップ７の下面が第１タクト板５に押圧接触し、第１タクト板５を２段階に弾性変形させた場合についても利用することができる。
【００３１】
前記実施形態例では、第１タクト板５の周辺部を第１端子２の接触部２１，２１に接触させるとともに、第２タクト板６の周辺部を第２端子３の接触部３１，３１に接触させた場合について説明したが、本発明はこれに限るものでなく、第１タクト板５の周辺部を第１端子２の接触部２１，２１に接触させる代わりに、第１タクト板５の周辺部を第１端子２の接触部２１，２１の上方に配置した場合、第２タクト板６の周辺部を第２端子３の接触部３１，３１に接触させる代わりに、第２タクト板６の周辺部を第２端子３の接触部３１，３１の上方に配置した場合、又は、第１タクト板５の周辺部を第１端子２の接触部２１，２１に接触させるとともに、第２タクト板６の周辺部を第２端子３の接触部３１，３１に接触させる代わりに、第１タクト板５の周辺部を第１端子２の接触部２１，２１の上方に配置するとともに、第２タクト板６の周辺部を第２端子３の接触部３１，３１の上方に配置した場合についても利用することができる。
【００３２】
例えば、第１タクト板５の周辺部を第１端子２の接触部２１，２１に接触させるとともに、第２タクト板６の周辺部を第２端子３の接触部３１，３１に接触させる代わりに、第１タクト板５の周辺部を第１端子２の接触部２１，２１の上方に配置するとともに、第２タクト板６の周辺部を第２端子３の接触部３１，３１の上方に配置した場合について説明すると、この場合、キートップ７の押圧で第１タクト板５を２段階に弾性変形させたときの、１段目の変形で第１タクト板５の周辺部を第１端子２の接触部２１，２１に接触させるとともに、凸部５６が第２タクト板６に押圧接触して第２タクト板６の周辺部を第２端子３の接触部３１，３１に接触させることによって、第１、第２端子２、３間の電気的な接続を行い、２段目の変形で第２タクト板６の中央部を第３端子４の接触部４１に接触させることによって、第１、第２、第３端子２、３、４間の電気的な接続を行う。
【００３３】
前記実施形態例では、所望の荷重特性を得るために、導電性金属板を打ち抜き、絞り加工したものを２枚重ねたもので第２タクト板６が形成された場合について説明したが、本発明はこれに限るものでなく、導電性金属板を打ち抜き、絞り加工したものを３枚以上重ねたもので第２タクト板６が形成された場合、又は１枚の導電性金属板の打ち抜き、絞り加工で第２タクト板６が形成された場合についても利用することができる。
【００３４】
前記実施形態例では、第２タクト板６がタクト板収容凹部１３内の所定位置からずれるのを防止するために、タクト板収容凹部１３の内底面の第２タクト板６の周辺部に臨設する部分に加締め部１７〜１７を形成した場合について説明したが、本発明はこれに限るものでなく、加締め部１７〜１７以外の手段で第２タクト板６がタクト板収容凹部１３内の所定位置からずれるのを防止したものについても利用することができる。
【００３５】
前記実施形態例では、第１タクト板５の１段目の変形時に撓みによる荷重の損失を抑え、キートップ７からの荷重を損失させることなく絞り部５８〜５８に伝えてクリック感を生じさせるために、中央接触部５１に立ち上げ片５７、５７を連設して中央接触部５１の強度を補強した場合について説明したが、本発明はこれに限るものでない。
例えば、図１６に示すように第１タクト板５の中央接触部５１の長手方向の端縁に折り返し片５７ａ、５７ａを形成した場合、図１７に示すように第１タクト板５の板面の長手方向に沿ってビード（ひも状の突起）５７ｂ、５７ｂを形成した場合、又は、中央接触部５１に立ち上げ片５７、５７及びビード５７ｂ、５７を形成した場合、若しくは中央接触部５１に折り返し片５７ａ、５７ａ及びビード５７ｂ、５７を形成した場合についても利用することができる。
【００３６】
前記実施形態例では、クリック感を生じさせるために、第１タクト板５を中央接触部５１、連結部５３、５３、環状部５４及び周辺接触部５５、５５で形成するとともに、環状部５４に絞り部５８〜５８を形成した場合についても説明したが、本発明はこれに限るものでなく、第１タクト板５は、ハウジング１のタクト板収容凹部１３内に収容されたときに、その中央部の上面がキートップ７に当接し、その周辺部が第１端子２の接触部２１、２１に常時接触し、その中央部の下面に１段目の変形時に第２タクト板６に接触する凸部５６が形成されたものについて利用することができる。
例えば、図１１〜図１３に示す第１タクト板５において、絞り部５８〜５８を省略した場合についても利用することができる
【００３７】
前記実施形態例では、２段動作プッシュスイッチ自体に本発明を利用した場合について説明したが、本発明は、これに限るものでなく、この２段動作プッシュスイッチをロータリースイッチと組み合わせた複合スイッチや、この２段動作プッシュスイッチをロータリーエンコーダスイッチと組み合わせた複合スイッチについても利用することができる。
【００３８】
【発明の効果】
請求項１に記載の発明は、２段動作プッシュスイッチのタクト板を第１、第２タクト板（５）、（６）で形成し、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させ、１段目の変形で凸部（５６）を第２タクト板（６）に接触させて第１、第２端子（２）、（３）間を電気的に接続し、２段目の変形で第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させて第１、第２、第３端子（２）、（３）、（４）間を電気的に接続するように構成した。このようにタクト板を第１、第２タクト板（５）、（６）の２つとし、第１、第２タクト板（５）、（６）のそれぞれに過度のストレスが生じないようにしたので、タクト板が１つの従来例と比べて長寿命化を図ることができるとともに、１段目の荷重特性と２段目の荷重特性の自由度を大きくして２段動作プッシュスイッチとしての荷重特性のバリエーションを広げることができる。
【００３９】
請求項２に記載の発明は、２段動作プッシュスイッチのタクト板を第１、第２タクト板（５）、（６）で形成し、キートップ（７）の押圧で第１タクト板（５）を２段階に弾性変形させ、１段目の変形で、第１タクト板（５）の周辺部を第１端子（２）の接触部（２１，２１）に接触させるとともに、凸部（５６）が第２タクト板（６）に押圧接触して第２タクト板（６）の周辺部を第２端子（３）の接触部（３１，３１）に接触させて、第１、第２端子（２）、（３）間を電気的に接続し、２段目の変形で、第２タクト板（６）の中央部を第３端子（４）の接触部（４１）に接触させて、第１、第２、第３端子（２）、（３）、（４）間を電気的に接続するように構成した。このようにタクト板を第１、第２タクト板（５）、（６）の２つとし、第１、第２タクト板（５）、（６）のそれぞれに過度のストレスが生じないようにしたので、タクト板が１つの従来例と比べて長寿命化を図ることができるとともに、１段目の荷重特性と２段目の荷重特性の自由度を大きくして２段動作プッシュスイッチとしての荷重特性のバリエーションを広げることができる。
【００４０】
請求項３に記載の発明は、　請求項１又は２に記載の発明において、第１タクト板（５）を中央接触部（５１）、連結部（５３，５３）、環状部（５４）及び周辺接触部（５５，５５）で形成し、環状部（５４）を外周側が下方へ傾斜した形状とし、環状部（５４）に絞り部（５８〜５８）を形成したので、第１タクト板（５）の１段目の変形で第１、第２端子（２）、（３）間を接続するときにクリック感を生じさせることができる。
【００４１】
請求項４に記載の発明は、　請求項３に記載の発明において、第１タクト板（５）の中央接触部（５１）をほぼ長方形状に形成し、中央接触部（５１）の長手方向に沿って立ち上げ片（５７，５７）とビード（５７ｂ，５７ｂ）の少なくとも一方を補強用として形成したので、中央接触部（５１）の撓みによる荷重の損失を抑え、キートップ（７）からの荷重を損失させることなく絞り部（５８〜５８）に伝えてクリック感を生じさせることができる。
【００４２】
請求項５に記載の発明は、　請求項３に記載の発明において、第１タクト板（５）の中央接触部（５１）をほぼ長方形状に形成し、中央接触部（５１）の長手方向に沿って折り返し片（５７ａ，５７ａ）とビード（５７ｂ，５７ｂ）の少なくとも一方を補強用として形成したので、中央接触部（５１）の撓みによる荷重の損失を抑え、キートップ（７）からの荷重を損失させることなく絞り部（５８〜５８）に伝えてクリック感を生じさせることができる。
【００４３】
請求項６に記載の発明は、請求項１、２、３、４又は５に記載の発明において、タクト板収容凹部（１３）の内底面に第２タクト板（６）の周辺部をほぼ固定するための加締め部（１７〜１７）を形成したので、第２タクト板（６）がタクト板収容凹部（１３）内の所定位置からずれるのを防止することができ、第１タクト板（５）の２段目の変形による第１、第２、第３端子（２）、（３）、（４）間の接続を確実にすることができる。
【図面の簡単な説明】
【図１】本発明による２段動作プッシュスイッチの一実施形態例を示す図２の断面図であって、（ａ）は図２のＡ−Ａ線断面図、（ｂ）は図２のＢ−Ｂ線断面図である。
【図２】本発明による２段動作プッシュスイッチの一実施形態例を示す平面図である。
【図３】図２の正面図である。
【図４】図１〜図３中のハウジング１を示す平面図である。
【図５】図４の正面図である。
【図６】図４の右側面図である。
【図７】図４のＡ−Ａ線断面図である。
【図８】図４のＢ−Ｂ線断面図である。
【図９】図４のＣ−Ｃ線拡大断面図である。
【図１０】図４中の第１、第２、第３端子２、３、４のハウジング１における配置状態を示す図で、（ａ）は平面図、（ｂ）は正面図である。
【図１１】図１〜図３中の第１タクト板５を示す平面図である。
【図１２】図１１のＡ−Ａ線断面図である。
【図１３】図１１の断面図であって（ａ）は図１１のＢ−Ｂ線断面図、（ｂ）は図１１のＣ−Ｃ線部分断面図、（ｃ）は（ｂ）のＤ−Ｄ線断面図である。
【図１４】図１〜図３中のキートップ７を示す縮小図で、（ａ）は平面図、（ｂ）は正面図、（ｃ）は底面図、（ｄ）は（ａ）のＡ−Ａ線断面図である。
【図１５】図１〜図３中のカバー８を示す縮小図で、（ａ）は平面図、（ｂ）は正面図、（ｃ）は右側面図である。
【図１６】第１タクト板５の第１変形例の要部を示す図で、（ａ）は要部平面図、（ｂ）は（ａ）のＡ−Ａ線断面図、（ｃ）は（ａ）のＢ−Ｂ線断面図である。
【図１７】第１タクト板５の第２変形例の要部を示す図で（ａ）は要部平面図、（ｂ）は（ａ）のＡ−Ａ線断面図、（ｃ）は（ａ）のＢ−Ｂ線断面図である。
【図１８】従来例を示す平面図である。
【図１９】図１８の正面図である。
【図２０】図１８の右側面図である。
【図２１】図１８のＡ−Ａ線断面図である。
【図２２】図１８のＢ−Ｂ線断面図である。
【図２３】図１８のＣ−Ｃ線断面図である。
【図２４】図１８〜図２３中のタクト板２００を示す図で、（ａ）は平面図、（ｂ）は（ａ）のＡ−Ａ線断面図である。
【符号の説明】
１…ハウジング、　１１…底板、　１２…側板、　１３…タクト板収容凹部、１４…位置合わせ凹部、　１５…加締め用突起、　１６…係止突起、　１７…加締め部、　２…第１端子、　２１…第１端子２の接触部、　２２…第１端子２の接続部、３…第２端子、　３１…第２端子３の接触部、　３２…第２端子３の接続部、　４…第３端子、　４１…第３端子４の接触部、　４２…第３端子４の接続部、　５…第１タクト板、　５１…中央接触部、　５２…孔、　５３…連結部、　５４…環状部、　５５…周辺接触部、　５６…凸部、　５７…立ち上げ片、５７ａ…折り返し片、　５７ｂ…ビード、　６…第２タクト板、　７…キートップ、　７１…操作部、　７２…押圧部、　７３…位置合わせ部、　７４…収容凹部、　８…カバー、　８１…キートップ用孔、　８２…係止ばね部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a two-stage push switch used for cameras, electronic devices, and the like. For example, it relates to a two-stage operation push switch used for a camera shutter.
[0002]
[Prior art]
As conventional two-stage operation push switches, those shown in FIGS. 18 to 24 are known. That is, a tact plate receiving recess 101 for receiving the tact plate 200 is formed in the housing 100, and the first, second, and third terminals 301, 302, and 303 are fixed to the bottom plate of the housing 100, and the first, second, and third terminals are formed. The contact portions (311, 311), (312, 312), and (313) of the three terminals 301, 302, and 303 are surrounded by the outer peripheral portion, the inner peripheral portion, and the central portion of the inner bottom surface of the tact plate receiving recess 101. The connecting portions 321, 321, 322, and 323 of the first, second, and third terminals 301, 302, and 303 protrude out of the housing 100. The opening surface of the tact plate receiving recess 101 is covered with a cover 400, and the operation unit of the keytop 500 is projected outward from a keytop hole 401 formed in the center of the cover 400, and formed on the side surface of the cover 400. The locking spring portions 402 to 402 are locked to locking projections 103 to 103 projecting from the outer surface of the housing 100, and the cover 400 is fixed to the housing 100.
[0003]
As shown in FIG. 24, the tact plate 200 is connected to a horizontal disk-shaped central contact portion 201 by semicircular holes 202, 202 on the outer peripheral side of the central contact portion 201, and to be connected by connecting portions 203, 203. It has an annular portion 204 and horizontal rectangular plate-shaped peripheral contact portions 205, 205 protrudingly provided at opposing positions on the outer peripheral side of the annular portion 204. The annular portion 204 is formed so that the outer peripheral side is inclined downward. The aperture portions 206 to 206 are formed at equal intervals along the circumferential direction of the annular portion 204 at a central angle of 90 °.
In the initial state, as shown in FIG. 22, the tact plate 200 is accommodated in the tact plate accommodating recess 101 in a state where it is slightly elastically deformed between the inner surface of the bottom plate of the housing 100 and the lower surface of the key top 500, and the peripheral contact portion 205, 205 are in contact with the contact portions 311, 311 of the first terminal 301.
[0004]
Then, when the key top 500 is pressed down, the pressing projection of the key top 500 pushes the center contact portion 201 of the tact plate 200 to invert the annular portion 204. Assuming that this deformation is a first-stage deformation, the peripheral portion of the central contact portion 201 comes into contact with the contact portions 312, 312 of the second terminal 302 due to this deformation, and electrically connects the first and second terminals 301, 302. Connecting.
Then, when the key top 500 is further pressed down, the pressing projection of the key top 500 further presses the center contact portion 201 of the tact plate 200, and the deformation proceeds. Assuming that this deformation is a second-stage deformation, the center of the central contact portion 201 comes into contact with the contact portion 313 of the third terminal 303 by this deformation, and the first, second, and third terminals 301, 302, and 303 are separated. Make an electrical connection.
[0005]
[Problems to be solved by the invention]
However, in the conventional example shown in FIGS. 18 to 24, two stages of connection are performed by one tact plate 200, so that excessive stress (stress) is applied to the connecting portions 203, 203 of the tact plate 200, and the connection is small. There is a problem that the tact plate 200 is damaged by the number of operations.
For example, in the first-stage deformation of the tact plate 200, the annular portion 204 formed by bending is inverted, and in the second-stage deformation of the tact plate 200, the center contact portion 201 formed by drawing is inverted. Therefore, there is a problem that cracks easily occur due to stress concentration in the connecting portions 203 at the boundary between the two.
Further, since two stages of connection are performed by one tact plate 200, the degree of freedom between the first stage load characteristics and the second stage load characteristics is small, and the variation of the load characteristics cannot be widened. there were.
For example, when the load characteristics of the first stage are adjusted to the desired characteristics, the influence is exerted on the load characteristics of the second stage, so that the degree of freedom of the load characteristics of the second stage is small, and it is difficult to obtain the desired characteristics. There was a problem.
[0006]
The present invention has been made in view of the above-described problems, and can extend the life, increase the degree of freedom of the first-stage load characteristics and the second-stage load characteristics, and improve the load characteristics. It is an object of the present invention to provide a two-stage operation push switch capable of expanding the range.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, a first, second, and third terminals (2) fixed to the housing (1) by forming a tact plate housing recess (13) for housing a tact plate in the housing (1). The contact portions (21, 21), (31, 31), and (41) of (3) and (4) are exposed to the outer peripheral portion, the inner peripheral portion, and the central portion of the inner bottom surface of the tact plate receiving recess (13). By pressing the key top (7) to elastically deform the tact plate, the first and second terminals (2) and (3) are brought into contact with the contact portions (21, 21) and (31, 31). Connection and connection between the first, second, and third terminals (2), (3), and (4) by contact with the contact portions (21, 21), (31, 31), and (41). A two-stage operation push switch for connecting in stages, wherein said tact plate is vertically separated in a tact plate receiving recess (13). The first and second tact plates (5) and (6) are formed, and the first tact plate (5) makes the peripheral portion contact the contact portions (21, 21) of the first terminal (2), A convex portion (56) is formed on the lower surface of the central portion, and the second tact plate (6) bulges upward at the central portion and contacts the peripheral portion with the contact portions (31, 31) of the second terminal (3). Then, the first tact plate (5) is elastically deformed in two stages by pressing the key top (7), and the convex portion (56) is brought into contact with the second tact plate (6) by the first stage deformation, and the two-stage The center portion of the second tact plate (6) is brought into contact with the contact portion (41) of the third terminal (4) by deformation of the eyes.
[0008]
In the above configuration, the tact plate is formed by the first and second tact plates (5) and (6), and the first tact plate (5) is elastically deformed in two stages by pressing the key top (7). The first step of the first tact plate (5) causes the projection (56) to contact the second tact plate (6) to electrically connect the first and second terminals (2) and (3). Then, by the second stage deformation of the first tact plate (5), the central portion of the second tact plate (6) is brought into contact with the contact portion (41) of the third terminal (4) to make the first, second, and second tact plates. The three terminals (2), (3) and (4) are electrically connected. The first and second tact plates (5) and (6) are used as tact plates to prevent excessive stress from being applied to each of the first and second tact plates (5) and (6). The degree of freedom between the first-stage load characteristics and the second-stage load characteristics can be increased.
[0009]
According to a second aspect of the present invention, the first, second, and third terminals (2) fixed to the housing (1) by forming a tact plate housing recess (13) for housing the tact plate in the housing (1), The contact portions (21, 21), (31, 31), and (41) of (3) and (4) are exposed to the outer peripheral portion, the inner peripheral portion, and the central portion of the inner bottom surface of the tact plate receiving recess (13). By pressing the key top (7) to elastically deform the tact plate, the first and second terminals (2) and (3) are brought into contact with the contact portions (21, 21) and (31, 31). Connection and connection between the first, second, and third terminals (2), (3), and (4) by contact with the contact portions (21, 21), (31, 31), and (41). A two-stage operation push switch for connecting in stages, wherein said tact plate is vertically separated in a tact plate receiving recess (13). Formed by the first and second tact plates (5) and (6), and the first tact plate (5) has a peripheral portion disposed above the contact portions (21, 21) of the first terminal (2). At the same time, a convex portion (56) is formed on the lower surface of the central portion, and the second tact plate (6) bulges upward at the central portion and contacts the peripheral portions of the second terminals (3) with the contact portions (31, 31). The first tact plate (5) is elastically deformed in two stages by pressing the key top (7), and the peripheral portion of the first tact plate (5) is subjected to the first terminal ( The contact portion (21, 21) of (2) is brought into contact with the protrusion (56), and the peripheral portion of the second tact plate (6) is pressed into contact with the second tact plate (6) by the second terminal (3). And the central part of the second tact plate (6) is brought into contact with the contact part (41) of the third terminal (4) by the second stage deformation. Than it is.
[0010]
In the above configuration, the tact plate is formed by the first and second tact plates (5) and (6), and the first tact plate (5) is elastically deformed in two stages by pressing the key top (7). In the first-stage deformation of the first tact plate (5), the periphery of the first tact plate (5) is brought into contact with the contact portions (21, 21) of the first terminal (2), and the convex portion (56). Presses into contact with the second tact plate (6) to bring the peripheral portion of the second tact plate (6) into contact with the contact portions (31, 31) of the second terminal (3), thereby forming the first and second terminals. (2) and (3) are electrically connected. In the second stage deformation of the first tact plate (5), the center of the second tact plate (6) is brought into contact with the contact portion (41) of the third terminal (4), so that the first, second, The third terminals (2), (3) and (4) are electrically connected.
The first and second tact plates (5) and (6) are used as tact plates to prevent excessive stress from being applied to each of the first and second tact plates (5) and (6). The degree of freedom between the first-stage load characteristics and the second-stage load characteristics can be increased.
[0011]
According to a third aspect of the present invention, in the first or second aspect, the first tact plate (5) is provided with a substantially horizontal plate-shaped central contact portion (51) in order to generate a click feeling. An annular portion (54) separated by a substantially semicircular hole (52, 52) on the outer peripheral side of the central contact portion (51) and connected by a connecting portion (53, 53), and an outer periphery of the annular portion (54) And a substantially horizontal rectangular plate-shaped peripheral contact portion (55, 55) projecting at a position opposing the first terminal (2) and contacting the contact portion (21, 21) of the first terminal (2). ) Is characterized in that the outer peripheral side is formed so as to be inclined downward, and aperture portions (58 to 58) are formed in the annular portion (54).
[0012]
According to a fourth aspect of the present invention, in the third aspect of the invention, the load from the key top (7) is transmitted to the throttle portions (58 to 58) of the first tact plate (5) without loss. The central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape whose longitudinal direction is the direction in which the central contact portion (51) is connected to the connecting portions (53, 53). At least one of a rising piece (57, 57) connected to the edge of the bead and a bead (57b, 57b) formed along the longitudinal direction of the plate surface of the central contact portion (51). The central contact portion (51) is provided for reinforcement.
[0013]
According to a fifth aspect of the present invention, in the third aspect of the present invention, the load from the key top (7) is transmitted to the throttle portions (58 to 58) of the first tact plate (5) without loss. The central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape whose longitudinal direction is the direction in which the central contact portion (51) is connected to the connecting portions (53, 53). At least one of the folded pieces (57a, 57a) connected to the end edge of the center part and the beads (57b, 57b) formed along the longitudinal direction of the plate surface of the center contact part (51) is positioned at the center. It is provided for reinforcing the contact portion (51).
[0014]
According to a sixth aspect of the present invention, in the first, second, third, fourth or fifth aspect, the second tact plate (6) is prevented from deviating from a predetermined position of the tact plate housing recess (13). Therefore, a caulking portion for substantially fixing the peripheral portion of the tact plate receiving recess (13) to a portion adjacent to the peripheral portion of the second tact plate (6) on the inner bottom surface of the tact plate receiving recess (13). (17 to 17) are formed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
1 to 3 show the overall configuration. In these figures, 1 is a housing, 2, 3, 4 are first, second, and third terminals, 5 is a first tact plate, and 6 is a second tact plate. A tact plate, 7 is a key top, and 8 is a cover.
[0016]
As shown in FIGS. 4 to 9, the housing 1 includes a rectangular bottom plate 11 and a side plate 12 that surrounds the bottom plate 11 integrally and vertically from the outer periphery thereof. An open tact plate receiving recess 13 is formed.
On opposite inner surfaces of the tact plate receiving recess 13, positioning recesses 14, 14 for positioning and receiving peripheral contact portions 55, 55 (described later) of the first tact plate 5 are formed.
The inner bottom surface of the tact plate receiving recess 13 includes a circular central portion, an annular inner peripheral portion continuing around the central portion, and an outer peripheral portion continuing around the outer peripheral portion of the inner peripheral portion, As shown in FIG. 7, the height of the surface is increased stepwise.
The inner bottom surfaces of the positioning concave portions 14 are part of the outer peripheral portion of the inner bottom surface of the tact plate receiving concave portion 13 and are formed at the same height.
At the inner peripheral portion of the inner bottom surface of the tact plate accommodating recess 13, arc-shaped caulking projections 15 to 15 for projecting and positioning the peripheral portion of the second tact plate 6 are provided.
Locking projections 16 to 16 for locking the cover 8 are formed on the outer surface of the side plate 12 of the housing 1.
[0017]
First, second, and third terminals 2, 3, and 4 are integrally provided on the bottom plate 11 of the housing 1 when the housing 1 is molded. For example, first, second, and third terminals 2, 3, and 4 as shown in FIGS. 10A and 10B are formed by press molding of a conductive metal plate, and are arranged in a mold. It is integrally molded by injection and solidification.
At this time, the contact portions 21 of the first terminal 2 protrude from the surrounding inner bottom surface at the inner bottom surfaces of the positioning concave portions 14 of the outer peripheral portion of the inner bottom surface of the tact plate receiving recess 13. And the connection portions 22 of the first terminal 2 protrude outside the housing 1.
In addition, the contact portions 31 of the second terminal 3 are located on the inner peripheral portion of the inner bottom surface of the tact plate receiving recess 13 and can be in contact with the peripheral contact portion of the second tact plate 6 from the peripheral inner bottom surface. It is exposed in a protruding state, and the connection portion 32 of the second terminal 3 protrudes outside the housing 1.
In addition, the contact portion 41 of the third terminal 4 is exposed at a center position of the center of the inner bottom surface of the tact plate receiving recess 13 so as to protrude from the surrounding inner bottom surface, and the connection portion 42 of the third terminal 4 is formed of a housing. 1 protrudes outside.
[0018]
The first tact plate 5 is formed by punching and bending a conductive metal plate having a thickness t (for example, t = 0.06 mm) having elasticity, and is accommodated in the tact plate accommodation recess 13. As shown in FIGS. 11 to 13, a horizontal substantially rectangular plate-shaped central contact portion 51 and band-like connecting portions 53, 53 which are separated by substantially semicircular holes 52, 52 on the outer peripheral side of the central contact portion 51. An annular portion 54 is connected to the annular portion 54, and peripheral contact portions 55, 55 in the form of a horizontal rectangular plate protrudingly provided at opposing positions on the outer peripheral side of the annular portion 54.
A convex portion 56 bulging downward is formed at the center of the central contact portion 51, and rising pieces 57, 57 bent upward are formed at the longitudinal edges of the central contact portion 51. .
The annular portion 54 is formed with squeezed portions 58 to 58 swelling upward at equal intervals along the circumferential direction at a central angle of 90 °.
[0019]
The second tact plate 6 is formed by punching and drawing a conductive metal plate having a thickness t (for example, t = 0.04 mm) having elasticity and drawing, and two sheets are stacked in the tact plate accommodation recess 13. As shown in FIG. 1, it is formed in a disk shape (ie, a dome shape) having a central portion bulging upward.
[0020]
The key top 7 is for pressing the first tact plate 5 to elastically deform in two stages. As shown in FIG. 14, the key top 7 is integrally connected to a columnar operation portion 71 and a lower portion of the operation portion 71. A substantially disc-shaped pressing portion 72, and a substantially rectangular positioning portion projecting integrally from the outer peripheral side of the pressing portion 72 and having a front end portion engaged with the positioning concave portions 14, 14 of the housing 1. The pressing portions 72 are formed on the lower surface with receiving recesses 74 for receiving the rising pieces 57 of the first tact plate 5.
[0021]
The cover 8 covers the opening of the tact plate receiving recess 13 and is fixed to the housing 1. As shown in FIG. 15, the outer edge is formed in substantially the same rectangular shape as the outer edge of the housing 1, and The key top 7 has a key top hole 81 for projecting the operating portion 71 of the key top 7 so as to be able to move up and down. Spring portions 82 to 82 are formed.
[0022]
Next, the assembly of the two-stage operation push switch configured as described above will be described.
(1) At the time of molding the housing 1, first, second, and third terminals 2, 3, and 4 are integrally formed on the bottom plate 11 of the housing 1 as shown in FIGS. 4 to 9. .
[0023]
(2) The second tact plate 6 is placed at a predetermined position in the tact plate accommodating recess 13 of the housing 1 and the crimping projections 15 to 15 are heated and bent inward as shown by arrows in FIG. Thus, caulking portions 17 to 17 as shown in FIG. 1B are used, and the peripheral portion of the second tact plate 6 is almost fixed. Thus, the peripheral portion of the second tact plate 6 is always in contact with the contact portions 31 of the second terminal 3.
[0024]
(3) Next, the first tact plate 5 is placed in the tact plate receiving recess 13 of the housing 1 while being positioned. That is, as shown in FIG. 4, the peripheral contact portions 55, 55 of the first tact plate 5 are aligned with the positioning recesses 14, 14 of the housing 1, and the first tact plate 5 is placed in the tact plate receiving recess 13. And the peripheral contact portions 55 are brought into contact with the contact portions 21 of the first terminal 2.
[0025]
(4) Next, the positioning portions 73 of the key top 7 are aligned with the positioning recesses 14 of the housing 1, and the first tact plate 5 is raised in the housing recesses 74 of the key top 7. The key top 7 is placed on the first tact plate 5 while accommodating the pieces 57, 57, the cover 8 is put on the key top 7, and the operation unit 71 is projected upward from the key top hole 81, so that the cover 8 is engaged. The stop spring portions 82 to 82 are pressed into the locking projections 16 to 16 of the housing 1 and locked, and the assembly is completed as shown in FIGS.
In the assembled state, the first tact plate 5 is accommodated in the tact plate accommodating recess 13 with its center contact portion 51 being slightly elastically deformed by being pressed by the pressing portion 72 of the key top 7, as shown in FIG. Thus, the peripheral contact portions 55 of the first tact plate 5 are always in contact with the contact portions 21 of the first terminal 2.
[0026]
(5) The two-stage operation push switch assembled as described above is placed, for example, at a predetermined position on a substrate (not shown), and then placed on the first, second, and third terminals 2. The third and fourth connection portions 22, 22, 32, and 42 are soldered to the wiring patterns on the substrate.
[0027]
Next, the operation of the embodiment will be described.
(1) When the key top 7 is pressed down in FIG. 1, the pressing portion 72 pushes the center contact portion 51 of the first tact plate 5 to invert the connecting portions 53 and 53 and to elastically deform the annular portion 54. Assuming that this deformation is a first-stage deformation, this deformation causes the convex portion 56 of the first tact plate 5 to come into contact with the central portion of the second tact plate 6 and electrically connects the first and second terminals 2 and 3 to each other. Connecting.
In the first-stage deformation, the connecting portions 53 and 53 are inverted, and the annular portion 54 on which the throttle portions 58 to 58 are formed is elastically deformed to generate a click feeling. At this time, since the rising pieces 57 of the central contact portion 51 reinforce the strength of the central contact portion 51, the loss of the load due to the bending of the central contact portion 51 is suppressed, and the load from the key top 7 is reduced. The click feeling can be transmitted to the diaphragm portions 58 to 58 without causing the click feeling.
In the first-stage deformation, the load characteristics representing the relationship between the load applied to the key top 7 and the stroke depend on the shape and structure of the first tact plate 5. Therefore, the load characteristics can be changed by changing the thickness and shape of the first tact plate 5 and the shapes of the constricted portions 58 to 58.
[0028]
(2) Then, when the key top 7 is further depressed, the convex portion 56 of the first tact plate 5 pushes the center of the second tact plate 6 to invert the second tact plate 6. Assuming that this deformation is a second-stage deformation, the center of the second tact plate 6 comes into contact with the contact portion 41 of the third terminal 4 due to this deformation, and the first, second, and third terminals 2, 3, and 4 Are electrically connected.
In the second-stage deformation, the second tact plate 6 is inverted to generate a click feeling.
In the second-stage deformation, the load characteristics indicating the relationship between the load applied to the key top 7 and the stroke mainly depend on the shape and structure of the second tact plate 6. Therefore, the load characteristics can be changed by changing the thickness, shape, and the like of the second tact plate 6.
Further, since the peripheral portion of the second tact plate 6 is almost fixed to the housing 1 by the caulking portions 17 to 17 of the housing 1, when the two-stage operation push switch is carried or the two-stage operation push switch is operated. The second tact plate 6 can be prevented from deviating from a predetermined position. For this reason, when the central portion of the second tact plate 6 is brought into contact with the contact portion 41 of the third terminal 4, the peripheral portion of the second tact plate 6 is displaced from the contact portions 31 of the second terminal 3, and the It is possible to prevent a state in which contact occurs.
[0029]
(3) When the pressing on the key top 7 is released, the key top 7 is pushed up by its own restoring force of the first and second tact plates 5 and 6, and the central portion of the second tact plate 6 contacts the third terminal 4. With the separation from the portion 41, the projection 56 of the first tact plate 5 is separated from the second tact plate 6 and becomes electrically disconnected, and returns to the initial state of FIG.
[0030]
In the embodiment, the case where the upper surface of the central portion of the first tact plate 5 is brought into contact with the lower surface of the key top 7 and the first tact plate 5 is elastically deformed in two stages by pressing the key top 7 has been described. However, the present invention is not limited to this, and a gap is provided between the upper surface of the central portion of the first tact plate 5 and the lower surface of the key top 7, and the key top 7 is pressed by the key top 7 so that the first tact plate 5 is pressed. It can also be used in a case where the first tact plate 5 is elastically deformed in two stages by pressing and contacting the first tact plate 5.
For example, by forming a step or a flange on the outer peripheral surface of the operation portion 71 of the key top 7 and interposing an elastic body between the step or the flange and the upper surface of the cover 8, the first tact plate 5 A gap is provided between the upper surface of the central portion of the key top and the lower surface of the key top 7, and the elastic body is elastically deformed by the pressing of the key top 7 so that the lower surface of the key top 7 comes into pressure contact with the first tact plate 5, and It can also be used for the case where the tact plate 5 is elastically deformed in two stages.
[0031]
In the embodiment, the peripheral portion of the first tact plate 5 is brought into contact with the contact portions 21 and 21 of the first terminal 2, and the peripheral portion of the second tact plate 6 is brought into contact with the contact portions 31 and 31 of the second terminal 3. Although the case in which the contact is performed has been described, the present invention is not limited to this, and instead of contacting the peripheral portion of the first tact plate 5 with the contact portions 21 and 21 of the first terminal 2, When the peripheral portion is arranged above the contact portions 21 and 21 of the first terminal 2, instead of bringing the peripheral portion of the second tact plate 6 into contact with the contact portions 31 and 31 of the second terminal 3, the second tact plate 6 is used. Is arranged above the contact portions 31 of the second terminal 3 or the peripheral portion of the first tact plate 5 is brought into contact with the contact portions 21 and 21 of the first terminal 2 and the second tact Instead of contacting the peripheral portion of the plate 6 with the contact portions 31 of the second terminal 3, The case where the peripheral portion of the contact plate 5 is disposed above the contact portions 21 and 21 of the first terminal 2 and the peripheral portion of the second contact plate 6 is disposed above the contact portions 31 and 31 of the second terminal 3 Can also be used.
[0032]
For example, instead of bringing the peripheral portion of the first tact plate 5 into contact with the contact portions 21 and 21 of the first terminal 2, and instead of bringing the peripheral portion of the second tact plate 6 into contact with the contact portions 31 and 31 of the second terminal 3. The peripheral portion of the first tact plate 5 is disposed above the contact portions 21 and 21 of the first terminal 2, and the peripheral portion of the second tact plate 6 is disposed above the contact portions 31 and 31 of the second terminal 3. In this case, when the first tact plate 5 is elastically deformed in two stages by pressing the key top 7, the peripheral portion of the first tact plate 5 is moved to the first terminal 2 by the first-stage deformation. The contact portions 21 and 21 of the second terminal 3 and the peripheral portion of the second tact plate 6 are brought into contact with the contact portions 31 of the second terminal 3 by pressing the second contact plate 6. Electrical connection between the first and second terminals 2 and 3 is performed, and the second By contacting the central portion of the tact plate 6 to the contact portion 41 of the third terminal 4, first, second, electrical connection between the third terminal and fourth performed.
[0033]
In the above-described embodiment, the case where the second tact plate 6 is formed by stacking two sheets obtained by punching and drawing a conductive metal plate in order to obtain a desired load characteristic has been described. However, the present invention is not limited to this. When the second tact plate 6 is formed by punching and drawing three or more conductive metal plates, or punching and drawing one conductive metal plate It can also be used when the second tact plate 6 is formed by processing.
[0034]
In the embodiment, in order to prevent the second tact plate 6 from deviating from a predetermined position in the tact plate housing recess 13, the second tact plate 6 is provided on the inner bottom surface of the tact plate housing recess 13 around the second tact plate 6. Although the case where the crimping portions 17 to 17 are formed in the portions has been described, the present invention is not limited to this, and the second tact plate 6 may be formed in the tact plate receiving recess 13 by means other than the crimping portions 17 to 17. It can also be used for a device that is prevented from deviating from a predetermined position.
[0035]
In the above embodiment, the loss of the load due to the bending when the first tact plate 5 is deformed at the first stage is suppressed, and the click from the key top 7 is transmitted to the narrowed portions 58 to 58 without losing the load. For this purpose, a case has been described in which the rising pieces 57, 57 are connected to the central contact portion 51 to reinforce the strength of the central contact portion 51, but the present invention is not limited to this.
For example, when folded pieces 57a, 57a are formed at the longitudinal edges of the central contact portion 51 of the first tact plate 5 as shown in FIG. 16, the plate surface of the first tact plate 5 is formed as shown in FIG. When beads (string-like projections) 57b, 57b are formed along the longitudinal direction, or when the rising pieces 57, 57 and beads 57b, 57 and the beads 57b, 57 are formed at the central contact portion 51, or the central contact portion 51 is folded. It can also be used when the pieces 57a, 57a and the beads 57b, 57 are formed.
[0036]
In the embodiment, in order to generate a click feeling, the first tact plate 5 is formed of the central contact portion 51, the connecting portions 53, 53, the annular portions 54, and the peripheral contact portions 55, 55, and the first tact plate 5 is formed on the annular portion 54. Although the case where the squeezed portions 58 to 58 are formed has been described, the present invention is not limited to this. When the first tact plate 5 is housed in the tact plate housing recess 13 of the housing 1, the The upper surface of the portion abuts on the key top 7, the peripheral portion thereof always contacts the contact portions 21 of the first terminal 2, and the lower surface of the central portion thereof contacts the second tact plate 6 during the first-stage deformation. It can be used for those having the convex portions 56 formed thereon.
For example, in the first tact plate 5 shown in FIGS. 11 to 13, it is also possible to use the case where the aperture parts 58 to 58 are omitted.
[0037]
In the above embodiment, the case where the present invention is applied to the two-stage operation push switch itself has been described. However, the present invention is not limited to this, and a composite switch combining the two-stage operation push switch with a rotary switch, A composite switch in which this two-stage operation push switch is combined with a rotary encoder switch can also be used.
[0038]
【The invention's effect】
The tact plate of the two-stage push switch is formed by first and second tact plates (5) and (6), and the first tact plate (5) is pressed by pressing the key top (7). ) Is elastically deformed in two stages, and the first stage deforms the protrusion (56) into contact with the second tact plate (6) to electrically connect the first and second terminals (2) and (3). The first and second and third terminals (2), (2) are connected by contacting the center of the second tact plate (6) with the contact portion (41) of the third terminal (4) by the second stage deformation. 3) and (4) are electrically connected. As described above, the tact plates are the first and second tact plates (5) and (6) so that excessive stress is not generated in each of the first and second tact plates (5) and (6). As a result, the life of the tact plate can be prolonged as compared with the conventional example, and the degree of freedom of the first-stage load characteristics and the second-stage load characteristics is increased so that the two-stage push switch can be used. Variations in load characteristics can be widened.
[0039]
The tact plate of the two-stage operation push switch is formed by first and second tact plates (5) and (6), and the first tact plate (5) is pressed by pressing the key top (7). ) Is elastically deformed in two stages, and in the first stage of deformation, the peripheral portion of the first tact plate (5) is brought into contact with the contact portions (21, 21) of the first terminal (2), and the convex portion (56) is formed. ) Is pressed against the second tact plate (6) to bring the peripheral portion of the second tact plate (6) into contact with the contact portions (31, 31) of the second terminal (3), and the first and second terminals are contacted. (2) and (3) are electrically connected to each other, and in the second stage deformation, the center of the second tact plate (6) is brought into contact with the contact portion (41) of the third terminal (4), The first, second, and third terminals (2), (3), and (4) are electrically connected. As described above, the tact plates are the first and second tact plates (5) and (6) so that excessive stress is not generated in each of the first and second tact plates (5) and (6). As a result, the life of the tact plate can be prolonged as compared with the conventional example, and the degree of freedom of the first-stage load characteristics and the second-stage load characteristics is increased so that the two-stage push switch can be used. Variations in load characteristics can be expanded.
[0040]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the first tact plate (5) is connected to the central contact portion (51), the connecting portions (53, 53), the annular portion (54) and the periphery. Since the annular portion (54) is formed by the contact portions (55, 55) and the outer peripheral side is inclined downward, and the narrow portions (58 to 58) are formed in the annular portion (54), the first tact plate (5) is formed. In the first-stage modification of (1), a click feeling can be generated when the first and second terminals (2) and (3) are connected.
[0041]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape and extends in the longitudinal direction of the central contact portion (51). Since at least one of the rising pieces (57, 57) and the beads (57b, 57b) is formed for reinforcement, the loss of load due to the bending of the central contact portion (51) is suppressed, and the distance from the key top (7) is reduced. The click feeling can be generated by transmitting the load to the throttle portions (58 to 58) without losing the load.
[0042]
According to a fifth aspect of the present invention, in the third aspect, the central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape and extends in the longitudinal direction of the central contact portion (51). Since at least one of the folded pieces (57a, 57a) and the beads (57b, 57b) is formed for reinforcement, the loss of the load due to the bending of the central contact portion (51) is suppressed, and the load from the key top (7) is reduced. Can be transmitted to the narrow portions (58 to 58) without causing loss of click, and a click feeling can be generated.
[0043]
According to a sixth aspect of the present invention, in the first, second, third, fourth or fifth aspect, the peripheral portion of the second tact plate (6) is substantially fixed to the inner bottom surface of the tact plate receiving recess (13). Since the caulking portions (17 to 17) are formed, the second tact plate (6) can be prevented from deviating from a predetermined position in the tact plate receiving recess (13), and the first tact plate (17) can be prevented. The connection between the first, second, and third terminals (2), (3), and (4) due to the second-stage deformation of 5) can be ensured.
[Brief description of the drawings]
FIGS. 1A and 1B are cross-sectional views of an embodiment of a two-stage operation push switch according to the present invention, in which FIG. 1A is a cross-sectional view taken along line AA of FIG. 2, and FIG. FIG. 3 is a cross-sectional view taken along line B.
FIG. 2 is a plan view showing an embodiment of a two-stage operation push switch according to the present invention.
FIG. 3 is a front view of FIG. 2;
FIG. 4 is a plan view showing the housing 1 in FIGS.
FIG. 5 is a front view of FIG. 4;
FIG. 6 is a right side view of FIG.
FIG. 7 is a sectional view taken along line AA of FIG. 4;
FIG. 8 is a sectional view taken along line BB of FIG. 4;
FIG. 9 is an enlarged sectional view taken along line CC of FIG. 4;
FIGS. 10A and 10B are views showing an arrangement state of first, second, and third terminals 2, 3, and 4 in a housing 1 in FIG. 4, wherein FIG. 10A is a plan view and FIG.
FIG. 11 is a plan view showing a first tact plate 5 in FIGS. 1 to 3;
FIG. 12 is a sectional view taken along line AA of FIG. 11;
13 is a sectional view of FIG. 11, wherein (a) is a sectional view taken along line BB of FIG. 11, (b) is a partial sectional view taken along line CC of FIG. 11, and (c) is a sectional view taken along line D of FIG. FIG. 4 is a sectional view taken along line -D.
FIGS. 14A and 14B are reduced views showing the key top 7 in FIGS. 1 to 3, wherein FIG. 14A is a plan view, FIG. 14B is a front view, FIG. 14C is a bottom view, and FIG. FIG. 4 is a cross-sectional view taken along line A.
15 is a reduced view showing the cover 8 in FIGS. 1 to 3, (a) is a plan view, (b) is a front view, and (c) is a right side view.
16A and 16B are diagrams showing a main part of a first modification of the first tact plate 5, wherein FIG. 16A is a plan view of the main part, FIG. 16B is a sectional view taken along line AA of FIG. It is a BB line sectional view of (a).
FIGS. 17A and 17B are views showing a main part of a second modification of the first tact plate 5, wherein FIG. 17A is a plan view of the main part, FIG. 17B is a sectional view taken along line AA of FIG. It is BB sectional drawing of a).
FIG. 18 is a plan view showing a conventional example.
FIG. 19 is a front view of FIG. 18;
FIG. 20 is a right side view of FIG.
FIG. 21 is a sectional view taken along line AA of FIG. 18;
FIG. 22 is a sectional view taken along line BB of FIG. 18;
FIG. 23 is a sectional view taken along line CC of FIG. 18;
24A and 24B are diagrams showing the tact plate 200 in FIGS. 18 to 23, wherein FIG. 24A is a plan view and FIG. 24B is a sectional view taken along line AA of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Housing, 11 ... Bottom plate, 12 ... Side plate, 13 ... Tact plate accommodation recessed part, 14 ... Alignment recessed part, 15 ... Caulking protrusion, 16 ... Locking protrusion, 17 ... Caulking part, 2 ... 1st terminal, Reference numeral 21: a contact portion of the first terminal 2; 22, a connection portion of the first terminal 2; 3, a second terminal; 31, a contact portion of the second terminal 3; 32, a connection portion of the second terminal 3; Terminal: 41: Contact portion of the third terminal 4, 42: Connection portion of the third terminal 4, 5: First tact plate, 51: Central contact portion, 52: Hole, 53: Connection portion, 54: Annular portion, 55 ... peripheral contact portion, 56 ... convex portion, 57 ... rising piece, 57a ... folded piece, 57b ... bead, 6 ... second tact plate, 7 ... key top, 71 ... operation section, 72 ... pressing section, 73 ... position Mating part, 74: accommodation recess, 8: cover, 81: key top hole, 82: locking spring part.

Claims

A contact plate receiving recess (13) for receiving a tact plate is formed in the housing (1), and the first, second, and third terminals (2), (3), and (4) are fixed to the housing (1). The portions (21, 21), (31, 31), and (41) are exposed to the outer peripheral portion, the inner peripheral portion, and the central portion of the inner bottom surface of the tact plate receiving recess (13), and are pressed by the key top (7). By elastically deforming the tact plate, the connection between the first and second terminals (2) and (3) by contact with the contact portions (21, 21) and (31, 31) and the contact portion (21, 21) ), A two-stage operation push for two-stage connection with the first, second and third terminals (2), (3) and (4) by contact with (31, 31) and (41). A first and second tact plates (1) and (2), wherein the tact plate is vertically separated in the tact plate receiving recess (13). ), (6), and the first tact plate (5) has a peripheral portion in contact with the contact portions (21, 21) of the first terminal (2) and a convex portion (56) on the lower surface of the central portion. The second tact plate (6) bulges upward in the center and makes the peripheral portion contact the contact portions (31, 31) of the second terminal (3), and is pressed by the key top (7). The first tact plate (5) is elastically deformed in two stages, the first stage deforms to contact the projection (56) with the second tact plate (6), and the second stage deforms the second tact plate (6). ), The center of which is brought into contact with the contact portion (41) of the third terminal (4).

A contact plate receiving recess (13) for receiving a tact plate is formed in the housing (1), and the first, second, and third terminals (2), (3), and (4) are fixed to the housing (1). The portions (21, 21), (31, 31), and (41) are exposed to the outer peripheral portion, the inner peripheral portion, and the central portion of the inner bottom surface of the tact plate receiving recess (13), and are pressed by the key top (7). By elastically deforming the tact plate, the connection between the first and second terminals (2) and (3) by contact with the contact portions (21, 21) and (31, 31) and the contact portion (21, 21) ), A two-stage operation push for two-stage connection with the first, second and third terminals (2), (3) and (4) by contact with (31, 31) and (41). A first and second tact plates (1) and (2), wherein the tact plate is vertically separated in the tact plate receiving recess (13). ), (6), and the first tact plate (5) has a peripheral portion disposed above the contact portions (21, 21) of the first terminal (2), and a convex portion ( 56) is formed, the second tact plate (6) bulges upward at the center portion and the peripheral portion is disposed above the contact portions (31, 31) of the second terminal (3), and the key top (7) is formed. ), The first tact plate (5) is elastically deformed in two stages, and the first stage deformation deforms the periphery of the first tact plate (5) into contact portions (21, 21) of the first terminals (2). And the convex portion (56) is pressed into contact with the second tact plate (6) to bring the peripheral portion of the second tact plate (6) into contact with the contact portions (31, 31) of the second terminal (3). A two-stage operation push switch, wherein the second stage deforms to bring the center of the second tact plate (6) into contact with the contact portion (41) of the third terminal (4).

The first tact plate (5) is separated from a substantially horizontal plate-shaped central contact portion (51) by a substantially semicircular hole (52, 52) on the outer peripheral side of the central contact portion (51), and is connected to the connecting portion ( The annular portion (54) connected by the first and second terminals (53, 53) and the contact portion (21, 21) of the first terminal (2) protrudingly provided at a position facing the outer periphery of the annular portion (54). A horizontal rectangular plate-shaped peripheral contact portion (55, 55) is formed, and the annular portion (54) is formed in a shape in which the outer peripheral side is inclined downward, and a narrowed portion (58-58) is formed in the annular portion (54). 3. A two-stage operation push switch according to claim 1, wherein:

The central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape whose longitudinal direction is the direction in which the central contact portion (51) is connected to the connecting portions (53, 53). At least one of the rising pieces (57, 57) connected to the edge and the beads (57b, 57b) formed along the longitudinal direction of the plate surface of the central contact portion (51) is brought into center contact. 4. The two-stage push switch according to claim 3, wherein the push switch is provided for reinforcing the portion.

The central contact portion (51) of the first tact plate (5) is formed in a substantially rectangular shape whose longitudinal direction is the direction in which the central contact portion (51) is connected to the connecting portions (53, 53). At least one of the folded pieces (57a, 57a) connected to the edge and the beads (57b, 57b) formed along the longitudinal direction of the plate surface of the central contact portion (51) is connected to the central contact portion. 4. The two-stage operation push switch according to claim 3, wherein the push switch is provided for reinforcement of (51).

A caulking portion (17 to 17) for substantially fixing the periphery of the second tact plate (6) to a portion adjacent to the periphery of the second tact plate (6) on the inner bottom surface of the tact plate receiving recess (13). 17. The two-stage operation push switch according to claim 1, wherein 17) is formed.