The purpose of the telescopic forks is to pick up and to put down pallets. Both arms of the fork move simultaneously. Each telescopic fork comprises of different blades driven by a chain which is in turn driven by an AC motor controlled by the frequency regulator. The position of the forks is measured by an encoder mounted on the driving shaft of the fork motor. Safety switches monitor if the forks are centered. When the rackstacker is riding, a brake on the fork motor, holds the forks in the central position.