Patent GB-909834-A (GB)
Title: An eccentric press
IPC: B21D28/00
Filed: 1958-12-18
Abstract: 909,834. Punching; metal marking presses. KONINKLIJKE METAALWARENFABRIEKEN VORHEEN J.N. DAALDEROP & ZONEN N.V. Dec. 18, 1958 [Dec. 20, 1957], No. 40889/58. Class 83 (4). A mechanical press has a flywheel 7 mounted in a press frame 2, 3 and adapted to be coupled to a main shaft 12 with an eccentric journal 17 carrying a first tool such as a punch 18, co-operating with a second tool such as a die 19, both tools mutually guiding each other, and bearing means 14, 15 within the flywheel for transmitting the pressing forces to the flywheel or the mainshaft so as to be absorbed thereby without being transmitted to the press frame. A flywheel 7 journalled in a pedestal bearing 3 is driven by belts running in grooves 11 and is adapted to be clutched to the mainshaft 12 by an electromagnetic coupling 13. A pair of segments 14, 15, split along line 16, Fig. 2, are mounted freely within the hollow flywheel. Segment 15 carries the die journal 27; segment 14 carries, through a bracket 21, a spring-loaded ball 23 for holding the punch journal 17 in the main shaft. A plate 28 secured to segment 14 carries a pin 30 engaging the bifurcated end 31 of a spring-biased bellcrank 34 pivoted at 31 and carrying a follower rollor 35 co-operating with a cam track 36 on the flywheel. In operation, strip 59 is fed continuously into the die and when it is about to be punched the lever 34 is moved by the cam track 36 whereby segments 14, 15 and hence journal 27 are rotated to co-ordinate the movement of the tools with the feed of the moving strip. Alternatively, the strip may be stopped by arresting members 41, 42 biased to grip the strip by spring 53 and opened by a lever 52 actuated by a cam segment 54 on the flywheel. The segments 14, 15 may be replaced by a single circular member. In another embodiment, Figs. 3, 4 (not shown), two segments are split along radial planes and have clearance between them the upper segment is fixed and the lower segment carrying the die journal is rotated by a cam track on the flywheel. In another embodiment, Fig. 8 (not shown), the two segments are journalled on the main shaft and in a further embodiment, Fig. 9 (not shown), both the punch and die journals are mounted in slide blocks which are movable laterally by linkage. In another embodiment, Figs. 5, 7, the flywheel 205 driven by a flat belt is frictionally engaged internally by rollers 214, 210 biased apart by an intermediate shaft 221. Roller 214 has a central spindle 211 with an eccentric journal 241 mounting the punch 243. Roller 210 has a central spindle 209 with an eccentric journal 240 for the die 242. In operation, drive is transmitted from roller 214 to spindle 211 by an electromagnetic coupling 235 and when the moving strip is about to be punched the spindle 209 is rotated by a cam 236 engaging a follower 237 whereby the die is moved laterally to co-ordinate the punching with the strip feed. Simultaneously, a second cam 234 actuates linkage 231, Fig. 6 (not shown), to rotate on eccentric shaft 230 which acts through linkage 225, to pull the shaft 221 further between the rollers 214, 210, Fig. 9, and hence increase the frictional drive. A gear drive may be used instead of the friction drive.