Hole punch and also a method for the piercing of a workpiece which is present as a foam material and/or as a sandwich material and also a method for the manufacture of the hole punch
A hole punch and a method for piercing a workpiece wherein a hole punch includes a sheet metal part and a piercing body attached thereto which carries out the piercing function and which is provided with a thread cylinder or can be provided with a thread cylinder, for example by pressing a threaded pin into a centrally arranged passage of the hole punch, wherein the hole punch can also be formed in one piece as a piercing body with a sheet metal-like flange. Furthermore a method is claimed for the manufacture of the hole punch.
1. A method for manufacturing a composite strip assembly of a plurality of like hole punches comprising: supplying a plurality of piercing bodies to a tool of a press, drawing a sheet metal strip off from a carrier and supplying it to the tool, and permanently securing the piercing bodies to separately formed sheet metal parts of the sheet metal strip at regular spacings along a longitudinal axis of the sheet metal strip.
2. A method in accordance with claim 1 , wherein the sheet metal strip having plural hole punches is one of cut into lengths including a plurality of the sheet metal parts and rolled up into a coil.
3. A method in accordance with claim 1 , wherein the tool is a progressive tool operating in strokes which carries out a plurality of operations for each stroke.
4. A method in accordance with claim 3 , wherein the plurality of operations include attachment of a plurality of piercing bodies for each stroke of the progressive tool.
5. A method in accordance with claim 4 , in which shaping work is simultaneously carried out at the sheet metal strip in the progressive tool.
6. A method in accordance with claim 5 , further including forming claws on the sheet metal parts configured to secure the sheet metal parts against rotation relative to a workpiece via the shaping work.
7. A method in accordance with claim 1 , further including securing the piercing bodies against rotation relative to sheet metal parts.