| 摘要 |
An electrically driven hand-held apparatus for body care, such as a toothbrush, operates by means of a rotating motor. An eccentric pin is driven by the motor and engages in a longitudinal slot defined by a fork which is secured to an instrument holder and in this manner sets the instrument holder supporting the treatment instrument such as the toothbrush in oscillatory motion about its longitudinal axis. In order to permit the oscillation amplitude to be adjusted without alteration of the oscillation frequency, the eccentric pin is fixed on a support inclined to its axis of rotation, the support being set in rotary motion by the motor shaft and the support being set in rotary motion by the motor shaft and the support being axially displaceable on its axis of rotation by means of an external operating knob. The effective eccentricity, that is to say the radial distance of the location of engagement in the longitudinal slot, of the eccentric pin from the axis of rotation of the support is thus variable. |
