Improvements in or relating to screws

Abstract

Abstract 501,548. Screwdrivers. BRADSHAW, G. Sept. 3, 1937, No. 24072. [Class 61 (iii)] [Also in Groups XXV and XV] A wood or metal screw 1 is formed with a screwthreaded axial bore 4 extending from the end face of the head towards or into the shank, the end face having a conical recess 2 forming a clutch surface, the screw being unprovided with any means whereby it may be screwed in other than the threaded bore and clutch surface. The recess 2 is relatively flat, extends to the periphery 3 of the end face, and receives the head 12 of a closure plug having a threaded or unthreaded shank 11 screwed or driven into the bore 4. The head 12 is curved or relatively flat and may be coloured or otherwise finished, and the plug may be made pf wood, synthetic resin, hardened steel or other metal. The screw I may be screwed into position by providing a threaded plug with a conical clutch surface 13 and a slot to receive a screwdriver. Alternatively, use may be made of the adaptor shown in Fig. 2 or the tool shown in Fig. 6. The adaptor comprises a screwthreaded shank 6, a conical clutch surface 7, hexagonal nut, portion 8, and a slot 9 for a screwdriver. The tool comprises a screwthreaded shank 15, conical clutch surface 16, and handle 17. Power driven screwdrivers also may be employed.

Inventors

No inventors recorded.

Bibliographic Details