Patent ID: 7568504

Claim:
A hydraulic cylinder ( 1 ) comprising a cylinder chamber ( 6 ), a piston head ( 4 ) within said cylinder chamber ( 6 ) forming two sub chambers ( 7 , 7 ′) of said cylinder chamber ( 6 ) one on each side of the piston head ( 4 ), and a piston rod ( 5 ) which runs from one side of the piston head ( 4 ) through at least one of said sub chambers ( 7 , 7 ′), wherein a hydraulic power unit ( 8 ) for operation of the hydraulic cylinder ( 1 ) is situated at least partly within the parts forming at least one of the piston head ( 4 ) and the piston rod ( 5 ), said hydraulic power unit ( 8 ) comprising a motor ( 10 ) and a hydraulic pump ( 11 ) positioned at least partly within the piston rod ( 5 ).