Patent ID: RE41156

Claim:
A brush comprising: an elongate core defining a central axis of the brush; bristles fitted radially into said core, the ends of said bristles defining the external surface of the brush, and the ends of the longest ones of the bristles defining an envelope surface; at least one notch in the external surface of the brush and comprising at least two secant faces, a first of said faces defining a non-concave notch back and having a height which varies along the axis, and a second of said faces defining a notch front and having a height which varies along the axis, said secant faces defining at their intersection a trough line, wherein the intersection of the notch front of one notch with the envelope surface of the brush or with the notch back of a second notch defines a peak ridge forming the vertex of an emergent angle (α), wherein the two secant faces are asymmetric and form a reentrant angle (β) of between 60° and 180° at any point along the trough line.