FORMFITTING SECURING DEVICE FOR A ROLLER

A formfitting securing device for a roller has a rotation blocking engagement part which is biased into an engagement position by means of a first spring. The first spring exerts a bias onto the rotation-blocking engagement part both in the engaged position as well as in the nonengaged position, and a bias is achieved in the non-engaged position by acting on the rotation-blocking engagement part by means of a second spring.