ES363314A1 - Improvements in or relating to presses - Google Patents

Abstract

In a drawing press in which a blank is gripped by a blank holder before a die engages the blank and is held until the die is disengaged from the deformed blank, means for operating the blank holder and die slides comprises a straight mandrel 23 supported on a fixed part 10 of the press, a first eccentric 31 rotatable about the axis of the mandrel, a first strap 33 embracing the eccentric 31, a connecting rod 37 between the strap and the die-slide, a link 43, Fig. 2, between a fixed axis and the strap, a second eccentric 45 rotatable about the mandrel's axis, a rockshaft 50 having an arm 49, a second strap 46 embracing the eccentric 45 and connected to the arm 49, linkage 52, 56 and (58, 59), Fig. 3 (not shown), between the rock shaft 50 and the blank holder slide, and means for driving the eccentrics. In the example, two parallel mandrels 23 each operate a connecting rod 37 for the die-slide and a pair of connecting rods 56 for the hold-down slide. Drive for the press is through a clutch 15 and a flywheel 15a to a shaft 13 having a brake 16. A pinion 17 on shaft 13 drives one of a pair of meshing gears 18 each of which drives one of a pair of shafts 19 having pinions 21, 22 driving gears 25, 26 on the mandrels. The first eccentric 31 and a pair of second eccentrics 45 are integral with the gear 25 and mounted on bearings 28 on the mandrel 23, or the eccentrics may be separate parts of different diameters connected by dog teeth. Bearings 32, 45 on the eccentrics carry the strap 33 and a pair of second straps 46. The hold-down links 52 are mounted in bearings 53 on the mandrel. Each mandrel may have an integral or separately-made gear and eccentric unit (79), Fig. 4 (not shown), for operating two die-slide connecting-rods (78, 83) and one hold-down connecting-rod. The gear is located next the second eccentric (85) and between the first eccentrics (75, 80). Instead of the mandrels remaining stationary they may be keyed to the eccentrics, the second eccentrics may be fixed to the ends of the mandrels outside of the press-frame, and if the mandrels rotate they may operate mechanism for feeding blanks into and out of the press.