| 摘要 |
There is disclosed a toothbrush 21 with curved bristles 41, 43, 45, 47 formed of natural or manmade fibers of thermoplastic or thermosetting material such as acetate fibers, rayon fibers, acrylic fibers, nylon fibers, polyamide resins, polyimide resins, phenolic resins, or urea resins; the bristles are set in two rows, at least one of the rows being offset from the center-line of the brush 21 and with a curvature which is concave viewed from the center-line of the brush; some embdiments have bristles with substantially uniform curvature and other embodiments have bristles wherein the curvature in non-uniform and the greatest curvature is approximately one-third of the length from the distal extremity of the bristle. Preferably the bristle distal extremities are at about a right angle to the proximal bristle portion and the brush optionally has a row of short straight bristles 39 parallel to the row of curved bristles on the concave curvature side of the curved bristles. In one embodiment the cross section of the bristles 49, 89 is triangular or other polygonal shape and approximately half of the bristles at the outer end portions of the bristle row are longer than others of the bristles and extend a greater distance from the bristle mounting face 37. A brush handle 23 has a generally circular cross section and is slightly flattened on one side 31 to facilitate controlled rotation of the brush about its longitudinal axis; the handle has circumferential grooves 27 for better gripping action. |
