Patent ID: 7383838

Claim:
A mechanical return blocking device comprising two cooperating and mutually displaceable parts: a first part wherein parallel to a longitudinal axis at least one set of tracks comprising a first track and a second track is provided, and that the second track comprises one or more retaining members and a sliding guide arranged at one end of the second track; a second cooperating part wherein a leg member comprising an engagement section for engagement with the tracks provided on the first part is provided, and that said leg member is biased towards the first part and that the engagement section is adapted to travel in the direction of the longitudinal axis; and further that the retaining members allows the engagement section of the leg member to move unhindered in a first direction on said second track towards the sliding guide but blocks movement in an opposite second direction and that the engagement section of the leg member after having passed the sliding guide moving in the first direction, and the travel direction is reversed, slides on the sliding guide, whereby the engagement section and thereby the leg member is directed from the second track to the first track for unhindered movement on said first track in said second direction.