The present invention relates to a hand piece of the electric toothbrush having a housing in which the drive unit is received therein. Has a rear housing opening or front housing opening, the housing is adapted opening of both to be closed by a cover in watertight manner and preferably moisture-proof. The cover and / or housing, the snap-in means are provided for fixing the snap cover to the housing and cover. The present invention aims to provide a combination of threaded engagement with the snap-in in order to release the snap-coupling between the housing and cover. Therefore, curved portion or draft tapered portion of one is provided on the cover and / or housing at least up against the long axis of the housing. The cover lifted in the axial direction by using a draft taper portion, the twisting about the longitudinal axis of the housing it, the snap-in means is released. The curved portion, to enable it to be threadedly engaged to the housing cover, is shifted to the axial movement of the cover release of the snap coupling, the rotational movement of the cover or the draft taper portion. The snap-in means, by twisting the cover, by the guide, which is constrained to be releasable in a power saving state, having a curved engagement or screw, fixed is forcibly canceled. And the curved portion or draft tapered portion to allow the curved engagement or screwed with snap coupling of housing and cover, by twisting the cover in order to remove the cover, hard bound in housing between the cover to convey a strong detergency make it easy to unpin in a power saving state snap coupling and at the same time allow. [Selection] Figure Figure 1本発明は、内部に駆動ユニットが受容されるハウジングを有する電動歯ブラシのハンドピースに関する。このハウジングは、前方ハウジング開口又は後方ハウジング開口を有し、いずれの開口も、好ましくは防湿及び防水方式でカバーにより密閉されるように適合されている。ハウジング及び/又はカバーには、カバーとハウジングにカバーをスナップで固定する為にスナップイン手段が備えられている。本発明は、カバーとハウジング間のスナップイン結合を解除する為にスナップインとネジ係合の組合せを提供することを目的とする。このため、ハウジングの長軸に対して上昇する少なくとも一つの抜き勾配テーパ部又は湾曲部が、ハウジング及び/又はカバー上に設けられている。カバーは、抜き勾配テーパ部を用いて、それをハウジングの長軸周
