GB230189A - Improvements in and relating to screwdrivers - Google Patents

Abstract

230,189. Henning, F. W. Dec. 8, 1923. Hand drills.-A screwdriver of the kind having means for holding the screw in position during screwing is provided with a chamber in which are mounted several rings of radially-disposed plungers chamfered on each side, and pressed against the screw for spiral springs. The stem of the screwdriver may be surrounded by a tube having a projecting handle and adapted to be clutched to the stem, so as to provide extra turning power. Constructions are also included comprising a simple archimedian screw action, or a combined ratchet clutch and archimedian screw device. The screwdriver may be replaced by a bradawl or drill. The rod a formed with a projection c to engage the slot in the head of the screw is rotatable within a guide tube d, on the forward end of which is secured a collar f. Rings of slots are cut through the collar and tube to receive a number of L-shaped bolts h chamfered at the ends and retained in position by annular springs k. The bolts h hold the screw resiliently whilst it is being positioned against, and driven into, the work. A handle e is provided on the guide tube d, and the latter may be made rigid with the driver a by means of a dog r engaging with the handle b. In the modification shown in Fig. 2, the driver a is rotated by a forward movement of the handle b, which is formed with a sleeve s extending into an enlarged portion of the guide tube d and has internal projections engaging a helical groove q in the driver a. When the handle is released it is forced outwards by a spring t with a rotary movement due to the helical groove q. In a further modification shown in Fig. 4 the driver a is similarly provided with a helical groove q engaged by internal projections on a collar u within a sleeve w. The forward end of the sleeve w moves over the driver a and its rear end is secured in the handle b. Two parts of a one-way clutch u<1> are formed respectively on one end of the collar u and on the adjacent part of the sleeve w, a light spring t' acting between rings y, x tending to keep the clutch in engagement. Rotary movement of the sleeve w relative to the guide tube d is prevented by projections on the outside of the sleeve, w engaging an internal groove z in the tube d. When the handle b is pushed in, the collar u becomes clutched to the sleeve w so that its inward movement rotates the driver a. The handle b may be rotatably connected to the sleeve w and the driver a operated by an oscillating movement of the guide tube handle e. A spring catch of the usual type may be fitted so that the screwdriver mav be removed and replaced by a different-sized screwdriver, bradawl, or drill.