Toothbrush construction comprises plastic layers of different hardness with bristles embedded in one layer and passing through the other

摘要

A neck(6) connects a brush handle to a brush head(2) comprising two or more plastic layers, one of which is soft and the other hard. Fixing ends of bristle bundles(4) are embedded in the first layer(8) and extend through the second layer(10). The head layers(8,10) are parallel to each other and the upper surface(12) of the brush head(2) through which bristles project is flat. A boundary between both layers is parallel to the upper surface(12) of the brush head. The second layer(10) forms the upper surface and extends continuously along the full length of the brush head. Anchoring clips(16) of the bristle bundles may be located at the boundary between both layers and are secured by the second layer which is of a hard material. An alternative form of the brush has a second layer comprising supports of hard material surrounding the bristle bundles(4) and connected together by ribs embedded in a soft material similar to the soft material of the first layer. The hard second layer is integral with the brush neck(6) and the soft first layer(8) forms the lower surface(14) of the head. Grooves may run transversely across the soft lower surface. A molded second layer in the form of a hard plate is joined to the hard brush neck by the soft material of the first layer. Similarly a series of plates along the head length are joined to each other and the brush neck by the soft first layer. In a further design the soft first layer lies between the hard second layer and an underside layer, also of hard material. An Independent claim is included for a process for manufacturing the brush in which the brush head is molded as a two or more layer component whose bristle ends are embedded in first soft layer injected onto the underside of the second layer.