Electric toothbrush
First Claim
1. An electric toothbrush having an elongate handle, an electric motor inside the handle, a drive shaft rotatable about a longitudinal axis of the toothbrush inside an elongate shank, a brush head mounted at a remote end of the shank carrying bristles extending general transversely to the longitudinal axis from the brush head, an eccentrically unbalanced drive shaft extension that is constrained by the brush head to be freely rotatable within a cavity in the brush head about said longitudinal axis, in which the brush head and the shaft extension are flexibly coupled to the remote end of the shank and to the drive shaft, respectively, such that when the drive shaft is rotated the brush head is caused to vibrate relative to the shank.
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Accused Products
Abstract
An electric toothbrush has an eccentric unbalanced drive shaft extension constrained by a brush head to rotate freely about a longitudinal axis inside a cavity in the brush head. The shaft extension and the brush head are flexibly coupled to a drive shaft and a remote end of a shank, respectively. When the shaft is rotated by an electric motor in a handle of the toothbrush, the brush head is caused to vibrate. The handle is not caused to vibration to any significant extent.
112 Citations
7 Claims
- 1. An electric toothbrush having an elongate handle, an electric motor inside the handle, a drive shaft rotatable about a longitudinal axis of the toothbrush inside an elongate shank, a brush head mounted at a remote end of the shank carrying bristles extending general transversely to the longitudinal axis from the brush head, an eccentrically unbalanced drive shaft extension that is constrained by the brush head to be freely rotatable within a cavity in the brush head about said longitudinal axis, in which the brush head and the shaft extension are flexibly coupled to the remote end of the shank and to the drive shaft, respectively, such that when the drive shaft is rotated the brush head is caused to vibrate relative to the shank.
Specification