A telescopic hydraulic cylinder has a number of sections of steel tubes with successively smaller diameters that nest inside each other. This results in a small compact hydraulic cylinder when in its retracted state that offers a long length of travel when extended. Telescopic cylinders usually extend from the largest stage to the smallest, this means that the largest stage with all the other sections nested inside will generally move first and complete its stroke before the next section moves. This will continue through all sections until the smallest section completes its stroke. The opposite can be said when the cylinder is retracting, the smallest section will fully retract before the next section moves and this will continue until all sections are fully retracted and nested back inside the main tube. Telescopic cylinders can be supplied as single acting/double acting or displacement types.

Benefits

  • Small compact design offering a long stroke
  • Perfect when space is at a premium
  • Good initial lift off capability in extension

Disadvantages

  • The force reduces with each section change during extension
  • Retraction force is limited by the smallest stage area
  • The cylinder speed increases with each change in stage
  • More complex design therefore more costly than other types of cylinders