US Patent 7547075 Fixing device for a shank chisel

A fixing device for a shank chisel including a base part to which a chisel holder is attached in a manner that enables it to be exchanged. The chisel holder has a chisel location for the shank chisel and has a supporting face on which the shank chisel can be supported. The chisel holder is coupled to the base part by a pivot bearing, and the chisel holder rests against a mating face of the base part. This invention provides a stress-optimized design for the above-mentioned arrangement. Thus, according to this invention, when the chisel holder is mounted, a contact area formed between the contact face and the mating face is located between a rotation axis or a rotation path of the pivot bearing and the supporting face.