Hydraulic ram with coaxial cylinders - has central telescopic flow tubes and apertures through cylinders

摘要

Each hydraulic cylinder, with the exclusion of the first which is largest in diameter, constitutes the piston of the preceding cylinder and the hydraulic cylinder of the following piston. All cylinders are divided into two compartments, connection being through radial apertures, except for the first cylinder. A telescopic tube coaxially fitted inside the assembly of cylinders communicates with the innermost cylinder. Connecting passages and apertures act alternatively for admission or discharge of the hydraulic fluid as the assembly extends or retracts.