Spot-weld connection dismantling tool for re-cycling work

摘要

The sheet is cut in a circle round the spot weld, etc. by means of a high impact energy punch (8) in cylinder shape and spherically depressed on its active face along the cylinder axis so the head of the connection centres the punch unit shortly before this engages the sheet in work. To obtain the cutting angle for punch cutting action, the punch face is milled out at 90 deg offset diametrally normal to the cylinder axis. At their apex the milling cuts are radiused to prevent notch-induced stress concentrations to give four-toothed geometry on the cutting face. This geometry gives rise on punch contact to symmetrically distributed peak stress points which in turn score or crack the sheet surface for progressive penetration of the sheet by the cutting edges of the punch. As it comes to rest on the sheet the punch should be guided in a circular cylindrical guide. The guided diameter of the punch exceeds that of the punch in the cutting area so as to prevent the punch jamming in the guide after the plastic deformation of the punch at the cutting edge in reaction to the sheet.