Image Number 4 for United States Patent #5110026.
The crank assembly of the advancing apparatus is eccentrically supported in an intermediate shaft. This intermediate shaft is in turn supported in an oscillating slide. Accordingly, the oscillating movement of the slide is superimposed over such of the driving pivot of the crank assembly. The intermediate shaft includes a cam disk. Due to the cam disk the intermediate shaft oscillates in operation and causes in turn the oscillating movement of the slide, which oscillating movement proceeds oppositely to the oscillating movement of the driving pivot. The sum of these two movements in the zones of the end positions thereof is accordingly zero. Accordingly, the driving pivot is at rest over a prolonged time span. Due to this prolonged rest period between individual feeding steps, elastical deformations of working structures and of the workpiece being worked upon, can attenuate and fade out prior to the working proper, and at the same time the length of the advancing is not subjected to a change. Furthermore, any clamping elements for the clamping of the workpiece can be lowered more slowly against the workpiece such that a lower energy of impact is produced. Conclusively, the workpieces are not subjected to a plastic deformation. The apparatus finds application specifically in punch presses.