GB212290A - Improvements in means for converting reciprocating motion into rotary motion - Google Patents

Abstract

212,290. Boden, G. T. Nov. 29, 1922. Teeth-cleaning appliances. - Screw and nut mechanism for converting reciprocating into rotary motion is arranged to provide for rotation of the driven shaft in either a right or a lefthand direction continuously or in opposite directions alternately, as desired. A form adapted to drive a rotary tooth-brush is shown in Fig. 9. The shaft or spindle is formed with a continuous groove in which a part a<1> running in one direction is arranged between two parts a, a<2> running in the reverse direction, a sleeve C reciprocable thereon carrying thread-engaging elements driving alternately according to the direction of reciprocation, so that if the sleeve is reciprocated over the threaded parts a, a', or a<1>, a<2> only continuous rotation in either a right or a left hand direction is obtained, whilst' if the sleeve is reciprocated over the full length of the thread, the resultant rotation is alternately in opposite directions. The number of reversals of the thread may be extended. The grooves may be duplicated or the shaft or spindle may be formed of twisted wire or rod. The sleeve C, Fig. 4, is provided with screwed or tightly-fitting end closures c riding freely on the spindle. An inner sleeve B pinned to or tightly fitting the outer sleeve C is provided with end notches or recesses, between which and the end closures c balls D ride freely in the grooves, ,being carried into engagement with the notches at one end of the sleeve or the other according to the direction of motion. The balls D may be replaced by equivalent members such as rings F, F<1>, Fig. 9, having internal projections engaging the grooves or screw threads, and lugs adapted to engage the end notches in the sleeve B. If the spindle A be held, for instance, by a swivel knob or head-piece, rotation is imparted by reciprocating the sleeve C, or the sleeve may be held stationary and the spindle reciprocated, being thereby caused to rotate. Instead of the inner sleeve B, ring-like members with suitable notches may be fixed in corresponding positions in the outer sleeve C. The rotary tooth-brush shown in Fig. 9 is carried by a spindle A of wire twisted to form threads of varying direction, as shown in Fig. 1, the spindle and nut member or sleeve C being arranged in a protective casing H outside which a gripping sleeve J is slidably mounted, being connected to the sleeve C through a longitudinal slot h. A shield K fitted to the front end of the casing forms a backing for the brush-head G.