HYDROCYLINDER WITH MOVABLE PISTON PART Russian patent published in 2015 - IPC F15B21/04 

FIELD: machine building.

SUBSTANCE: hydrocylinder comprises a casing, a rod cavity and a rodless cavity which are formed by coupled piston and rod. A double piston is divided into a movable part and a fixed part and is fitted by passage ports in every part. A remote electromagnetic turning mechanism affecting the movable piston part is built-in in the hydrocylinder rod. In the open position the passage ports of the movable piston part match the passage ports of the fixed piston part due to the operation of the turning mechanism. In the closed position the movable part is turned by such an angle that provides for closing of the passage ports of the fixed part, simultaneously the passage ports of the movable part are closed by the fixed part of the double piston.

EFFECT: reduced time for heat pretreatment of a hydraulic drive.

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