Automatic screw-driving device

Claim 1

An automatic screw-driving device comprising; a housing of a rectangular cross-sectional shape, having (1) an interior cavity for a sliding box to fit and move therein, (2) two rails on an upper and a lower inner wall for rail grooves of the sliding box to fit with, (3) two holes respectively in an upper wall and a slide wall for an orienting rod to pass through, two orienting rods respectively fitting in a long slot in a sliding box and a shaft; a stop block fixed in a rear side opening of the housing; a sliding box having (1) a screw passageway of a cross shape extending from an upper surface down to a bottom for a screw belt to enter an entrance in the bottom and to move up gradually and (2) a curved hole in an intermediate portion of the screw passageway for a screw to go out, (3) a front side wall provided with a shaft hole and a small threaded hole, (4) a hollow cavity formed with a sustaining block fixed in a rear side opening and (5) a guide opening respectively at two opposite sides; a sprocket member combined just behind the front side wall of the sliding box, having (1) a plurality of pawls around its front circumference, (2) a plurality of bead holes around an front side surface, (3) a central shaft hole for one end of a shaft to fit therein, (4) a one-way bearing fixed in the shaft hole for sustaining the shaft. The shaft being placed between said sprocket member and said sustaining block fixed in a rear side opening of said sliding box, having a smallest diameter left end portion and a largest diameter intermediate long portion and a medium right end portion and a non-straight groove in the intermidiate portion, for a orienting rod to insert and move therein; an adjustable cap of a U-shape being combined with the front portion of the sliding box to be pulled out or in of the sliding box, having (1) a horizontal slot in one side wall, (2) two horizontal parallel rods in the opposite side wall, and (3) a a screw exit hole in the front side wall; and said pawls of the sprocket member pushing and moving up the screw belt to locate a screw at a pre-set position for being driven, said sprocket member never rotating in a reverse direction even if said shaft is rotated in the reverse direction, said shaft having a lengthwise slot for the one of two orienting rods of the housing to fit therein and being rotated for an angle by the orienting rod in case of manually pulling the sliding box, said adjustable cap being pulled out of the sliding box to adjust a distance to extend out of the sliding box to suit to a screw to be driven.