Patent GB-659607-A (GB)
Title: Improvements in or relating to screw drivers
IPC: B25B23/06
Filed: 1949-09-20
Abstract: 659,607. Inserting screws; chucks. KODAK, Ltd. Sept. 20, 1949, No. 24192. Convention date, Sept. 23, 1948. [Class 83 (iii)] A screw driver for use with screw sticks according to Specification 543,497 and particularly those with round head screws comprises a screw-driving element 18 mounted to rotate in a bracket 4 slidably mounted on a column 1 and including a collet 19 for engaging the screw head or heads, of a screw stick S1, behind the screw to be driven into the workpiece W, the collet, which is screwed to a sleeve 20s, co-operating with a sleeve 24, forming part of the element 18, and being moved axially relatively thereto by means of toggle levers 26, 27 which are straightened, to lock the collet, by moving a tapered sleeve 33 downwardly by means of a lever 35, carrying a handle which is moved from the position shown in Fig. 1 towards the left into the vertical position. The collet is released by centrifugal action when the lever 35 is moved back to the position shown. The lever 35 is provided with an arm 42 which is connected to the sleeve 33 by means of a pin-and-cam slot connection, the lever being pivoted at 36 on the bracket 4. The screw driver comprises also a screw-advancing mechanism mounted in alignment with the element 18 and comprising a sleeve member 15, Fig. 5, carried by a support 14 adjustably mounted on the column 1, having a tubular member 64 slidably mounted therein, the members 15, 64 having spring pawls 81, 82 respectively for engaging behind the screw heads of a second screw stick S2 disposed within the member 64. The upper end of the member 64 is connected to the member 15 by means of a tension spring 71. The round heads of the screw stick are of cylindrical or tapered shape and may be provided with notches, flats, or serrations. Operation.-When the screw heads are engaged by the collet jaws, the screws are rapidly rotated and downward movement on the handle H brings the end of the screw stick S1 into contact with the threaded aperture T of the workpiece W causing the end screw to be driven into the workpiece until the head seats on the workpiece and the narrow neck between the head and the next adjacent screw is twisted off. The screw driver is then moved upwardly by means of the handle H, assisted by a spring 6, and during the upward movement, the handle is also moved to the right, as shown, to release the collet. The screw stick, however, cannot move because of a spring pawl 45. As the screw driver is moved upwardly, a nut 53 on the upper end thereof engages the lower edge 85 of the screw-advancing mechanism. Meanwhile, the bottom screw of the screw stick S2 engages the head of the uppermost screw of the screw stick S1. As upward movement of the nut S3 continues, the member 64 is moved upwardly against the action of the spring 71 in which position, the pawl 82 snaps over a screw head as it approaches the pawl 81. Thus, when the screw driver is moved downwardly again, the spring 71 moves the member 64 downwardly to advance the screw stick S2 by the length of one screw. Specifications 548,655 and 557,527 also are referred to.