| 摘要 |
The vertically upwardly and downwardly movable tool plate (2) of the punching unit is suspended on each of mutually opposite sides from a lever system which has two lower angle levers (4) and one upper angle lever (5), each with a vertical and a horizontal lever arm. The two lower angle levers (4) and the upper angle lever (5) are each rotatable at their angle corners about a fixed axis (8, 11), and their vertical lever arms (4a, 5a) are connected to one another by means of a sliding joint (6). The horizontal lever arms (4b) of the lower angle levers (4) carry the tool plate (2), and the horizontal lever arms (5b) of the upper angle levers (5) carry counter- weights (16). Mounted between the two lever systems is a double eccentric (15) having diametrically opposite eccentric pins (14, 14') which are connected by means of links (12, 12') to the sliding joint (6) of one lever system or the other respectively, in such a way that, during the rotation of the double eccentric, the tool plate (2) and the counterweights (16) are moved upwards and downwards in opposite directions in order to achieve mass compensation. |
