GB197834A - Improvements in rotary tooth brushes - Google Patents

Abstract

197,834. Cruikshank, J. R. May 19, 1922. Hand-supported power-driven brushes; rotary brushes; brush sheaths and cases. - A rotary toothbrush comprises a member 1 having therein a socket to receive detachably the end of a stem 13 carrying brushing material 14, the member being rotatably mounted in a sleeve 2 extended forwardly to form a guard partly surrounding the bristles. The brush is rotated in either direction by means of a double archimedean screw 4, connected to the member 1 and engaging nuts 6, 7, slidably mounted within a handle 5. Either nut may be prevented from relative rotation with respect to the handle by a member 8 slidable in a slot 9 in the handle 5 and adapted to move a projection into or out of engagement with a notch in each of the nuts. One end of the screw 4 is attached to a washer 11, between which and the inner end of the handle 5 is placed a spring 12 adapted to return the handle to normal position after it has been pushed inwardly to rotate the brush. The brushing material 14 may comprise radial bristles of the form shown. In another form a series of circular brushes are arranged side by side on the brush stem. If desired, a brush of ordinary form may be used, in which case the screw 4 is locked to the handle 5 by pressing the handle inwardly and rotating partly a ring 21 thereon to depress a pin into engagement with an annular groove 22 formed on the screw. The brush when not in use is covered by a cap provided with a clip for attachment to a vest pocket.