Threaded-Body Cylinders with Locking Piston

Application
Hydro cylinders with locking piston have a relatively little clamping force, but a high retention force in opposite direction. Therefore they are particularly suitable for clamping of thin-walled workpieces with minimum deformation as well as for “floating clamping”.

Description
Hydro-cylinders with locking piston are single acting plunger cylinders. When pressurising the element, the piston will be expanded and locked in the cylinder body. The hydro-cylinder with locking piston does not only clamp the workpiece, but compensates also the machining forces which are up to five times higher and are directed against the clamping force.

Function
If a force F_B higher than the hydraulic clamping force F_hyd, acts on a standard clamping cylinder, the piston will be pushed back due to the compressibility of the oil.
In such cases the operating pressure has to be increased or a larger clamping cylinder or additional work supports have to be used. The hydro cylinder with locking piston does not only clamp the workpiece, but compensates also the machining forces which are up to five times higher and are directed against the clamping force.

Simple collet for ”floating clamping”

Two clamping bars with threaded-body cylinders with locking piston are fixed on a base plate and hydraulically connected by drilled channels. The axial block fixed in the centre is used as guide for both clamping jaws. An installed return spring moves the clamping jaws to its off-position.
"Floating" clamping, i.e. the uniform and tongs-type contact at the workpiece independent of its position is possible due to the hydraulic pressure compensation between the cylinders. Only different spring forces can influence the uniformity. After the pressure increase, the two locking pistons avoid a ”further floating” of the clamping point.