| 摘要 |
1278114 Shearing HAMMERLE AG MASCHINENFABRIK 3 Nov 1969 [15 Nov 1968] 53740/69 Heading B3W Plate shears comprise afixed blade 3, amovable blade 5 inclined relative to the blade 3 and two rows of pistons 9 and 13 on the delivery side of the shear which are locked in a position in which they support a workpiece 7 at the level of the shear table 2, by e.g. a pawl 20, until or shortly before the blade 5 reaches the workpiece in the region of the respective pistons. When the pawls are withdrawn the support faces 10 and 14 are lowered to the broken line position of Fig. 1 i.e. below an inclined roller table. The pistons 9 and 13 are staggered relative to each other and the roller table consists of parallel carriers 16 for rollers 17 spaced alternately by a piston 9 and a piston 13. The pistons are raised by fluid pressure, e.g. oil, and lowered by gravity or a spring (not shown). Each pawl may be withdrawn from a notch in the piston, against the action of a spring 21, by engagement of a cam 25, coupled to the drive of blade 5, with a lever 22. Antifriction rollers or balls may be arranged between chamfered faces on the pawl and the piston. In an alternative embodiment, Fig. 6 (not shown), the pawl (29) is ejected from the notch by pressure exerted by the blade through the workpiece against the action of an hydraulic cylinder (30). In a further embodiment (Fig. 5) pressure medium supplied to the cylinder via a non-return valve holds the piston in the raised position until a relief valve is opened by the action of a cam. |
