Patent ID: 7334785

Claim:
A locking vise for pipes, useful in operations for welding portions of plastic pipe by polywelding of a head portion of the plastic pipe, comprising: two mutually opposite jaws which form, when clamped, a circular locking seat for a portion of pipe, a slot being formed on a surface of each jaw in order to accommodate a corresponding portion of a reduction body for reducing a diameter of the circular locking seat of the pipes, said reduction body being substantially C-shaped in a longitudinal direction thereof, and said reduction body having a first end and a second end, means for fixing said first and second ends of said reduction body to a corresponding one of said jaws being further associated with each reduction body, said fixing means comprising a first locking pin at said first end of said reduction body, which can perform an axial translational motion and is inserted through said slot transversely to said slot at a first end of said slot, said first locking pin having, in an axial direction, a first part, which forms, when arranged in said slot at said first end thereof, an undercut for preventing extraction for said reduction body, and a second part, which is recessed with respect to said first part and forms, when arranged in said slot at said first end thereof, a disengagement configuration for the reduction body, said fixing means further comprising a second locking pin at said second end of said reduction body and inserted through said slot transversely thereto and at a second end of said slot.