Patent ID: 7487709

Claim:
An adjustable-length actuating element, comprising an energy storing device ( 15 , 46 , 46 ′, 69 , 69 ″′); a casing ( 2 , 28 , 2 ″′); a piston rod ( 9 , 9 ′, 39 , 39 ′, 9 ″′) which is extended from the casing ( 2 , 28 , 2 ″′) and movable relative thereto and has an external end; a first fastening element ( 4 , 33 , 33 ″′) on the end of the casing ( 2 , 28 , 2 ″′) opposite to where the piston rod ( 9 , 9 ′, 39 , 39 ′, 9 ″′) exits; and a second fastening element ( 22 , 45 , 45 ″′) on the external end of the piston rod ( 9 , 9 ′, 39 , 39 ′, 9 ″′); a spindle drive which is integrated in the energy storing device ( 15 , 46 , 46 ′, 69 , 69 ″′) and disposed between the casing ( 2 , 28 , 2 ″′) and the piston rod ( 9 , 9 ′, 39 , 39 ′, 9 ″′); and a driving shaft ( 24 , 26 a ), which is in rotary driving connection with the piston rod ( 9 , 9 ′, 39 , 39 ′, 9 ″′).