Concentric clamping elements

Application
This hydraulically-operated concentric clamping element can be equipped with especially low clamping jaws to receive workpieces with interior centrings of low depth.
Suitable workpieces can directly rest on the clamping jaws so that additional support points are not required.
With a combination of 2 and 3-point elements, workpieces with 2 centring holes can be exactly positioned.

Description
The 2 or 3 base jaws are coupled to a coneshaped contact bolt in the centre of the housing, that is driven by a double acting hydraulic piston.
To obtain the required synchronization accuracy all parts are manufactured with high precision. The nitrated base jaws have 3 fixing threads. 
Depending on the desired centring diameter, the  accordingly adjusted clamping jaws can always by fixed with at least 2 screws.
Theexact position of the clamping jaws is secured with 2 drill bushings.

Positive air pressure connection
The standard positive air pressure protection keeps the hole centre free of swarf, so that the base jaws can freely return.

Pneumatic stroke end control
The positive air pressure protection can also be used for the control of the unclamping position. The returning clamping jaws close in their end position the bore hole of the positive air pressure connection.

Optional contact control
In the version with contact control, pneumatic pressure is supplied to one of the base jaws, which is then transmitted into the clamping jaw.
In the crowned clamping surface there is a small bore hole. If a workpiece is clamped correctly, it closes the bore hole.