Patent ID: 8240440

Claim:
An apparatus for lifting a hatch which can pivot with respect to a stationary component around a pivot axis by means of a piston-cylinder unit, the piston cylinder unit comprising: a closed cylinder filled with a fluid, the cylinder having opposite ends, one of said ends being hinged to one of said hatch and said stationary component; a piston dividing said cylinder into first and second working chambers, the piston being axially movable in the cylinder, the piston having a piston chamber configured as a through-channel leading from the first working chamber to the second working chamber, a first input into the piston chamber arranged on a face of the piston facing the first working chamber, a valve seat arranged at an end of the first input in the piston chamber, a closing element arranged in the piston chamber configured to mate with the valve seat, and at least one biasing element arranged within the through-channel configured to bias the closing element; a piston rod having a coaxial bore, being fixed to the piston and passing through the second working chamber, the piston rod being guided through a first seal at one end of the cylinder and being hinged to the other of said hatch and said stationary component; and a solenoid-operated valve which can open and close the through-channel in the piston comprising a closing element which is biased toward one of an open and a closed position by the at least one biasing element configured as a spring, said valve being electrically actuated to move the closing element toward the other of the open and closed position; the solenoid-operated valve comprising a ferromagnetic core movably supported in the piston chamber and a coil mounted in the piston chamber, the coil surrounding the ferromagnetic core and extending axially with respect to a path of movement of the core; power lines extending through the coaxial bore and connecting to the coil; and a second seal comprising a plastic sealing compound filling an area in the piston between the coaxial bore and the piston chamber and surrounding the coil, the second seal sealing the piston chamber from the coaxial bore and holding the coil in the piston chamber, the power lines connecting to the coil through the plastic sealing compound.