Motor driven tooth brush - has flexible shaft with bristles, which is curved, remains straight and coaxial when stressed

摘要

The motor driven both brush consists of a flexible shaft (2) at the end of which are bristles on a bristle holder (3). The shaft (2) achieves a to and fro rotary movement on its lengthwise axis, and has a maximum brushing amplitude, with normal contact pressure. When unstressed, the bristle shaft (2) is curved. The strength of the bristle shaft (2) is such that it remains straight and coaxial to its pivot axis, with a stress of approximately 0.2 Kp.