Patent ID: 6138310
Filing Date: 2000-10-31
Classification: A46B,A61C

Abstract:
An electric toothbrush comprising a power handle portion and a brush head portion;said power handle portion having a longitudinal axis, and being adapted to provide a housing for an electric motor and for a driving mechanism located at a first end of said power handle portion;said driving mechanism being powered by said electric motor, and including a drive shaft having a longitudinal axis, and being adapted for frictional coupling to a drive pin mounted on said brush head portion;said drive shaft being driven by said electric motor so as to effect a linear reciprocating motion in a direction along its longitudinal axis;said brush head portion having a longitudinal axis, and being removably attachable at a first end thereof to said first end of said power handle portion;said brush head portion comprising a drive pin located at said first end thereof for frictional coupling in force transmitting relationship with said drive shaft, said drive pin being aligned along said longitudinal axis of said drive shaft;said brush head portion further comprising a pair of opposed bristle head portions arranged so as to present two groups of opposed bundles of bristles disposed substantially perpendicularly each to the other;each of said groups of bundles of bristles on each respective bristle head portion comprising a plurality of rows and a plurality of columns of bristle bundles, where the rows of bristles bundles are aligned parallel to the longitudinal axis of said brush head portion, and the columns of bristle bundles are aligned perpendicular to the longitudinal axis of said brush head portion;wherein the bristles in each bundle in each row of bristle bundles on each bristle head portion are substantially equal in length, where the length of the bristles in the respective row of bristle bundles on each bristle head portion which is closest to the longitudinal axis of said brush head portion is shorter than the length of the bristles in the respective row of bristle bundles on each bristle head portion which is furthest away from the longitudinal axis of said brush head portion, and wherein the lengths of the bristles in each respective row of bristle bundles on each bristle head portion are progressively longer in each row of bristle bundles which is further away from the longitudinal axis of said brush head portion than an adjacent row of bristle bundles which is closer to the longitudinal axis of said brush head portion;whereby a reciprocating linear motion is imparted to said brush head portion and thus to each of said opposed bristle head portions, and said reciprocating linear motion is in a direction parallel to said longitudinal axis of said brush head portion.