Patent ID: 7674065

Claim:
A device for locking the end positions of movable switch parts, comprising two relatively axially displaceable parts capable of being displaced into a position coupled with each other in a positive manner in at least one direction of movement, wherein the relatively displaceable parts comprise a tube ( 2 ) and a rod ( 3 ) guided within the tube ( 2 ) and are at least partially arranged in an outer tube ( 1 ), and locking members cooperate with the relatively axially displaceable parts ( 2 , 3 ) and the outer tube ( 1 ) and are capable of being displaced in the radial direction into a locking position in a recess ( 5 ) of the outer tube ( 1 ), wherein the locking members comprise ring segments ( 6 ) whose substantially rectangular cross sections are chamfered on their two inwardly located sides forming first abutment surfaces ( 9 ) converging obliquely toward an axis of the rod ( 3 ), wherein said first abutment surfaces ( 9 ) cooperate with oblique counter abutment surfaces ( 10 ) provided in a recess ( 8 ) of the rod ( 3 ) for holding the rod ( 3 ) and the tube ( 2 ) in said position coupled with each other during a first displacement path of the rod ( 3 ) in a direction of movement and for urging the ring segments ( 6 ) in an outward direction to emerge from said recess ( 8 ) of the rod ( 3 ) and to slide onto an outer surface ( 7 ) of the rod ( 3 ) adjacent said recess ( 8 ) of the rod ( 3 ) and to immerse into said locking position in the recess ( 5 ) of the outer tube ( 1 ) upon movement of the rod ( 3 ) relative to the tube ( 2 ) over a second displacement path in said direction of movement, wherein curvature of an inner surface ( 13 ) of the ring segments ( 6 ) corresponds to curvature of said outer surface ( 7 ) of the rod ( 3 ) adjacent said recess ( 8 ) of the rod ( 3 ) and curvature of an outer surface ( 18 ) of the ring segments ( 6 ) corresponds at least partially to curvature of an inner surface ( 16 ) of the outer tube ( 1 ) adjacent said recess ( 5 ) of the outer tube ( 1 ).