Abstract: An electric toothbrush with a control circuit capable of stopping the brushing operation when the brush is pressed against an user's teeth with an excessive force. The electric toothbrush comprises a housing which carries a shaft mounting a brush. The housing incorporates a rotary electric motor and a motion conversion mechanism which converts a rotational movement of the motor to a reciprocatory movement of the shaft for reciprocating said brush. A pressure sensor is provided to sense a brush pressure being applied back to the brush as a counter-action when pressing the brush against the user's teeth and to produce a stop signal when the sensed brush pressure exceeds a predetermined limit level.

Abstract: A powered dental floss includes a floss and a hand grip provided with an output shaft which has a longitudinal axis and to which the floss is coupled. The hand grip incorporates a motor and a drive mechanism which is powered by the motor to impart a vibrating motion to the output shaft. The floss is stretched substantially in parallel with the longitudinal axis of the output shaft so that it is driven to vibrate along its length for effectively cleaning between the teeth.

Abstract: A thin-walled can for sealingly enclosing liquid or gas, including a dome section, a counter section, a ground section, a heel section, and a side wall section, is improved so as to enhance pressure-proofness for a given wall thickness or to reduce wall thickness for a given pressure-proofness. A cross sectional shape of the dome section is formed of a curve whose radius of curvature changes substantially continuously along the curve, and the counter section contiguous to the dome section is formed so as to align with the direction of extension of the dome section. Preferably, the angle formed between the cross-section of the counter section and a vertical line is chosen to be within the range of 0.degree. to 15.degree.. Furthermore, preferably the cross-sectional shape of the heel section extending from the counter section through the ground section to the side wall section is a circular arc that is inwardly convex.

Abstract: A transmission gearing in which an eccentric cam includes first and second eccentric cam parts and a cam follower has contact faces abutting these eccentric cam parts so that, when a driving source rotates either in normal or reverse direction, the gearing provides as an output one of two different directional motions at the cam follower, with either one of the first and second eccentric cam parts positioned concentric with their pivot shaft without shifting the cam itself in diametral direction in gearing casing. The gearing arrangement is thereby simplified and minimized in required mounting space so as to realize a high compactness of the gearing.

Abstract: The disclosure is directed to substances composed of arsenic, sulphur and silver or of germanium, sulphur and silver in a certain range of proportions which may produce electrolytes having standard electrical properties, and also having stable vitreous state, whereby the electrolytes are easy to work and manufacture as small circuit elements.

Abstract: Vitreous photoconductive material having a composition xGeS.sub.2 -- yGes--zMS, which does not contain arsenic, but has good thermal stability.