Polyamide or polyester toothbrush not liable to crack when bristle anchors are inserted - is moulded with small diametrical slots in each bristle hole, to holds its bristles anchor firmly but without overstressing material

摘要

A brush, and a tooth brush in particular, has a main body and bristles arranged in bundles, each of which is folded over into a simple loop; each bundle is fixed by an anchor in a preformed hole, where the anchor is somewhat longer than the dia. of the hole and is locked at each end in the main body. Anchor slots are premoulded into both sides of the hole to match the length of the anchor; the thickness of the anchor is slightly larger than the width of the anchor slots. The whole structure is pref. made of polyamide or polyester. Pref. the figure shows a plan view of the main body (which is attached to a handle in the usual way). It has a number of moulded-in holes (2) for the bundles of bristles. The holes (2) are produced with two fine diametrically opposite slots (9, 10) when being moulded to fit the length of the anchors (4) which extend across the holes. Each anchor (4) is slightly greater (15) that the width of these slots (9, 10) the difference depending upon the actual polymers of the structure but also allowing the anchors to be inserted mechanically without overstressing the body (1). Each slot (9, 10) is some 0.2-0.5 mm deep (16). ADVANTAGE - The design eliminates the risk of producing hair cracks or other damage when forcing the anchors into position.