GB606866A - Improvements in or relating to drives for press tool punch shaping machines - Google Patents

Abstract

606,866. Shaping curved surfaces. THORN, L. R., and LENNIE, M. F. Jan. 21, 1946, No. 2048. [Class 83 (iii)] In the drive for a machine for shaping a press tool punch having a straight and a radiused portion, wherein a slidable and pivoting tool holder is operated by a cam through a pair of link mechanisms, the cam has two tracks, each link mechanism comprises a slide bar with a pair of cam followers, one for each cam track, and one slide bar is moved by one cam track during the cutting stroke and by the other track during the return stroke. A tool carrier 52, Figs. 2 and 3, is pivotally mounted at 49 on two slides 50 on pillars 51 on each side of the machine and is connected by a pin 71 on each side to a link 69 having a pivot-pin 68 which engages a horizontal slot 70 in a rearward extension 55 of the slide 50 and a vertical slot 67 in a frame 65 which slides on guides 66 on the machine frame. A cam 15, Fig. 1, is rotated by a shaft 20 and has two tracks 16, 17, which reciprocate slide bars 21, 22. During clockwise rotation from the position of the cam shown in Fig. 1, the bar 22 will remain stationary while the track 16, acting on the roller 23 on the bar 21, will move it to the left and through a link 25, bell-crank lever 26, 28, rod 29, yoke 60., arms 61 on sleeves 62 mounted on a shaft 44, levers 63 and links 64, will reciprocate the frame 65 so that the tool carrier 52 is pivoted round the pin 49 to cut the radius portion at the bottom of the work-piece 12. Subsequently, while the bar 21 remains stationary so that the tool stays withdrawn from the work, the track 16 acting on the roller 23 on the bar 22 will move it upwards, and, through the link 33, lever 34 pivoted at 40, rod 38, lever 43 attached to the shaft 44 and levers 46, each having a groove for a sliding block 48 engaging the outer end of the pivot-pin 49, will move the tool carrier upwards on the return stroke. The track 17 acting on the rollers 24, which are shorter than the rollers 23 so as to pass under the track 16, then restores the tool to the cutting position and actuates the linear cutting stroke. The cam tracks are so shaped that the rollers maintain contact with their respective tracks throughout the working cycle. The rods 38 and 29 are adjustable on their respective levers 34, 28 so that their stroke can be adjusted and the levers 46 may be adjustably fitted on the shaft 44 so that the starting point of the cutting stroke may be varied.