Patent ID: 7448477

Claim:
A device for displacement of an object ( 4 ) a certain distance which object is displaceable between a forward position ( 9 ) and a rearward position ( 10 ), said device comprising: a driving unit ( 14 ) displaceable between a first position ( 12 ) and a second position ( 13 ) for driving an object ( 4 ) a distance corresponding to a distance between the first and the second positions ( 12 , 13 ) by means of a friction joint ( 15 ) when the driving unit ( 14 ) is displaced from the first position to the second position ( 12 , 13 ), said friction joint being configured to enable displacement of the driving unit ( 14 ) and the object ( 4 ) relative to each another under the influence of a certain lowest force; a spring member ( 16 ) arranged to act on the driving unit ( 14 ) in a direction towards the second position ( 13 ) by means of a spring force; and an interconnecting component ( 21 ) that interconnects the driving unit ( 14 ) and the object ( 4 ), the interconnecting component ( 21 ) having a surface ( 22 ) that forms the friction joint ( 15 ) in cooperation with a surface ( 23 ) of the driving unit, and the interconnecting component ( 21 ) and the object ( 4 ) being interconnected so that the interconnecting component ( 21 ) and the object ( 4 ) are locked against displacement relative to one another when the object ( 4 ) is acted on in a direction towards the forward position ( 9 ) and the interconnecting component ( 21 ) is acted on in an opposite direction, for driving the object ( 4 ) to the rearward position ( 10 ) by means of the interconnecting component ( 21 ) when the driving unit ( 14 ) is displaced to the second position ( 13 ) during influence of the spring member ( 16 ) and for driving the driving unit ( 14 ) to the first position ( 12 ) by means of the interconnecting component ( 21 ) when the object ( 4 ) is displaced to the forward position ( 9 ); wherein the interconnecting component ( 21 ) and the object ( 4 ) are arranged relative to each other so that a play space ( 27 ) having an extension in a direction which is substantially perpendicular to the displacement direction of the object between the forward and the rearward positions is formed between the interconnecting component ( 21 ) and the object ( 4 ), the play space being sufficient to prevent undesired force from being transferred from the object ( 4 ) to the interconnecting component ( 21 ) and to the friction joint ( 15 ).