Drill for portable drilling machine, screw holding bit and method for manufacturing these tools

Abstract

Abstract The drill has a drill shank 13 with at least one chip-removal flute 14, cutting edges 15, a chucking shank 11 and driving surfaces 16 which lie between these parts outside the chucking area and serve to transmit the rotary movement to the tubular body 40 of a holder for a screwdriver bit. The smallest envelope circle 22 circumscribing the driving surfaces 16 has a larger diameter than the chucking shank 11 and the cutting edges 15. The holder for the screwdriver bit consists of a tubular body 40 with a longitudinal opening 41 as well as the front inner dog 42 serving to accommodate a screwdriver bit 70 and the rear inner dog 43 driven by the driving surfaces 16 of the drill. In the area facing the rear dog 43, the cross-sectional area 53 of the longitudinal opening 41 is greater than the cross-sectional area of the dog 43. The driving surfaces 16 of the drill are produced by recesses 18 being formed without chip removal by several radially acting metal-forming tools in the cylindrical section lying in front of the chucking shank 11 of the same diameter, and by the material displaced in the process forming the driving surfaces 16. By in each case at least two metal-forming tools acting radially on the tubular body 40, the front and rear inner dogs (42, 43) of the holder for the screwdriver bit are reduced in diameter until the dogs (42, 43) are formed by mandrels projecting in the front and respectively rear area of the tube. <IMAGE>

Inventors

• 👤 Werner Dipl.-Ing. Dipl.-Wirtsch.-Ing. Kleine

Bibliographic Details