Shears with bolt and nut

摘要

The shears have a bolt (4) passing through both blades, and a nut (1) on a thread (3) on the end of the bolt. The nut is in the form of a dish spring. In at least one of the two cylinder base surfaces, it has a recess getting deeper towards the thread boring, with an annular contact surface round it. The nut may have one or more slits in a direction parallel to the central axis of the cylinder. When the nut is screwed onto the bolt, the nut first comes into contact with the nearest blade (5), solely along the contact surface (11). Only when the nut is fairly tight are the nut and blade in contact over the entire cylinder base surface.