On a toothbrush

Abstract

A toothbrush has a head, and a handle; the head is formed with upper and lower portions joined to each other, which together have an inverted L shaped cross-section. The upper portion of the head is joined to the handle such that the head is rotary. The head has first and second bristles on a lower side of the upper portion, and an inner side of the lower portion respectively. Thus, the first and the second bristles can be pressed against, and moved over, top and one of lateral surfaces of a row of teeth for cleaning both of them respectively at the same time; the head turns to change orientation thereof relative to the handle according to curvature of different sections of a row of teeth, on which it is being moved along, thus increasing smoothness of movement thereof.

What is claimed is:  
     
         1 . An improvement on a toothbrush, comprising 
 a head joined to a handle thereof; the head including an upper portion and a lower portion projecting down from the upper portion, which together has an inverted L shaped cross-section; the head being rotary on the handle with an engaging protrusion on an upper side of the upper portion being fitted into an engaging hole of the handle; the head having first and second bristles on a lower side of the upper portion, and an inner side of the lower portion respectively;    whereby top and one of two lateral surfaces of a row of teeth can be cleaned at a same time with the first and the second bristles being pressed against, and moved over, both of them respectively; the head turning to change orientation thereof relative to the handle according to curvature of different sections of a row of teeth, on which it is being moved along, thus helping increase smoothness of movement thereof.