Patent ID: 7255111

Claim:
A dental floss applicator comprising: a housing formed of two cover shells, said housing having a first axle, a second axle, a through hole, and a recessed chamber; a dental floss stick, said dental floss stick having a rear side fastened to a front side of said housing, a front side adapted to support a length of a dental floss in a stretched status, and a floss groove for guiding a dental floss over the front side of said dental floss stick; a take-up wheel pivotally mounted in said through hole of said housing and fastened up with a shaft for securing one end of a dental floss and taking up the secured dental floss; a floss spool rotatably supported on said first axle, said floss spool having a gear wheel fixedly provided at one side thereof, said floss spool rolling up a dental floss, which has one end extending through the floss groove over the front side of said dental floss stick and connected to said take-up wheel; a spring rack mounted inside said housing, said spring rack having a press portion extending out of said housing for pressing by the user, a stop portion suspended inside said housing, said stop portion having a contact face engaged with said gear wheel, a receiving chamber, a spring member mounted in said receiving chamber and stopped between one sidewall of said receiving chamber and a part of said housing, and a through hole; a rotary knob mounted in said recessed chamber of said housing, said rotary knob having a shank inserted through the through hole of said spring rack and connected to said shaft for rotating said take-up wheel, and a series of sloping teeth extending around and inner circumference thereof; and a springy ratchet mounted on the shank of said rotary knob in said recessed chamber of said housing, said springy ratchet having a plurality of toothed blocks engaged with the sloping teeth of said rotary knob, wherein when said rotary knob is rotated, said take-up wheel and said shaft are rotated, and said springy ratchet is forced to tremble, and said stop portion of said spring rack is disengaged from said gear wheel for allowing rotation of said gear wheel on said second axle during trembling of said springy ratchet, and therefore said take-up wheel is synchronously rotated with said rotary knob to take up the dental floss from said spool and to wind the used length of the dental floss round said take-up wheel again.