Features & Benefits

KALLER Controllable Gas Spring (KF-springs) is a family of gas springs, for use in press tools. They can be locked in their bottom position where the return stroke of the spring can be controlled.

The KF springs can be used where, for instance, the blank holder should be locked in its bottom position to avoid deformation of the formed part or when it's beneficial for the transportation of the part.

The controllable springs are available as 15 kN, 30 kN, 50 kN, 75 kN springs with stroke length from 10 to 160 mm. As the stroke length always has to be fully utilised, the springs can be ordered with any stroke length between 10 and 160 mm (in incremental steps of 1 mm).

For optimal function the full stroke should be used within ± 0,5 mm.
The return stroke of the springs is normally controlled using the control system of the press. The springs can be installed self-contained or connected to a control unit through a hose system. The recommendation is to connect them to a control unit. The basic version of the springs, called KF, will have a small spring back of 1 mm before it comes to a complete stop.

If desired, this spring back can be fully eliminated by connecting the KF spring, through a valve block, to a passive spring (KP).

One or more KF spring/springs connected to a KP spring is called a KF + KP system.

The two different 'versions' can be seen below.
KF (max 1 mm spring back)


KF + KP System (zero spring back)