Quick release star knobs GN 6336.3 are used in such applications where the knob has to be completely removed after the releasing operation and refitted rapidly for re-clamping.
The knob is tilted over the threaded spindle. When in position, the knob is brought into a straight position for meshing of the two threads on nut and spindle. The knob will then have to be turned only by fraction of a rotation to achieve clamping.
Functional safety exists only if the clamping surface lies at a right angle to the threaded bolt.