Crank-operated flying shear - has lower blade holder sliding on rocking upper blade holder levers

摘要

The upper and lower knife holders swing to and fro in a portal-type frame, in which the upper holder is supported, typically by means of rollers running on straight faces on the portal columns. The upper holder rocks on levers extending downwards, with guides in them in which the lower holder moves up and down. The rocking movement can be caused by a ram coupled to the levers. The upper holder can be moved by a rod linked to an eccentric on a crankshaft and the lower one by a ram operated wedge piece sliding between a block and the underside of the holder.