Patent ID: 8915114

Claim:
A tool for cold expansion of fastener holes comprising a mandrel with a conical working part, such that between the mandrel and the hole to be worked is placed a longitudinally split into three or more parts cylindrical sleeve with a conical hole at one end whose cone angle is equal to an angle of the mandrel working conical part, wherein the cylindrical sleeve ( 4 ) is entirely split from end to end into separate, laterally touching one another without a clearance, segments ( 6 ), which are fixed in a cylindrical hole ( 14 ) of a threaded bush ( 7 ) and along the outer cylindrical surface ( 8 ) of the mandrel ( 1 ), such that the threaded bush ( 7 ) fixes the segments ( 6 ) in axial direction as well and serves for an immovable fixation of the split sleeve ( 4 ) to a driving device, and each segment ( 6 ) gets into contact with the conical surface ( 2 ) of the mandrel ( 1 ) along only one generatrix ( 16 ), laying in the symmetry plane ( 17 ) of the respective segment for each reciprocal position of the mandrel ( 1 ) and segments ( 6 ).