Drive mechanism for power device

A drive mechanism for an electric appliance, comprising:

• a tubular grip housing having a first end and a second end and defining a longitudinal length between the first and second ends;
• a pivot housing mounted within the grip housing, the pivot housing having a fixed portion and a free end, the free end spaced from the grip housing such that the free end is movable within the grip housing;
• a motor mounted within the pivot housing, and an eccentric weight extending from the motor, the motor operable to rotate the eccentric weight about a motor axis that extends parallel to the longitudinal length of the grip housing;
• a brush shaft extending along the longitudinal length of the grip housing and beyond the first end of the grip housing, the brush shaft having a handle end mounted to the pivot housing and a brush end opposite the handle end, the brush end adapted to receive a toothbrush head having a plurality of cleaning elements;
• and
• a power source within the grip housing adapted to activate the motor and rotate the eccentric weight, such that the free end of the pivot housing is driven to move by the movement of the eccentric weight, wherein a portion of the pivot housing bends about a pivot axis that is perpendicular to the motor axis, and the brush end of the brush shaft oscillates about the pivot axis.

A method for operating an electric toothbrush drive mechanism, comprising:

• providing a tubular grip housing having a first end and a second end and defining a longitudinal length between the first and second ends;
• inserting a pivot housing within the grip housing, the pivot housing having a fixed portion, a free end and a pivot axis between the fixed portion and the free end, the fixed portion engaging the grip housing, the free end spaced the grip housing;
• a motor mounted within the pivot housing, and an eccentric weight extending from the motor on a motor shaft that extends parallel to the longitudinal length of the grip housing;
• mounting a brush shaft along the longitudinal length of the grip housing, the brush shaft having a handle end mounted to the pivot housing and a brush end opposite the handle end, the brush end adapted to receive a toothbrush head having a plurality of cleaning elements;
• and
• operating the motor to rotate the eccentric weight, such that the free end of the pivot housing is driven to move within the grip housing by the movement of the eccentric weight, wherein a portion of the pivot housing bends about the pivot axis and the brush end of the brush shaft oscillates about the pivot axis.