All standard types of hydraulic cylinders have a limitation in their ability to be used in applications where an extended stroke length is required. This is the simple fact that the overall size of the cylinder is limited to the specific application or equipment and, since the rod is a single, solid piece, this limits the lift, push, pull or lower ability.
The answer to that problem is addressed through a telescopic cylinder. This is a particular design that allows the rod to be divided into sections fit into each other, largest at the outside to smallest on the inside.
As hydraulic fluid is pumped into the cylinder on a single acting telescopic cylinder the sections of the rod, known as the stages, extend to create the lift or push. The largest section of the rod, moves first, followed by each subsequent stage until the last and smallest in diameter.
The Load Capacity
Designing a telescopic cylinder is an extremely precise engineering task. The length of the extended telescoping rod has to be carefully considered in relationship to the weight of the load to provide enough rigidity to prevent bending.
Incorrect design of the stages or the wrong load capacity rating for these types of cylinders will dramatically decrease their life and increase damage to the cylinder in typical use.
The Single Action Advantage
With the vast majority of applications, the best option for operating the cylinder is single action. This is our specialization at Southern Hydraulic Cylinder, Inc. and it is extremely effective with the telescopic models. The use of the single acting cylinder not only cuts costs to manufacture the cylinder but reduces the need to run two hydraulic lines while also decreasing the amount of maintenance required once the cylinder is installed. The only necessity when using the single action telescopic is that there must be enough weight to allow gravity to compress the cylinder once the push or stroke is complete.