SITEMA Clamping Devices - SITEMA - #11

Clamping devices are clamping or braking units which act infinitely-variably on smooth round rods and are operated either hydraulically or pneumatically, and in special cases, also mechanically. We distinguish according to the function principle between Safety Catchers, Safety Brakes, Safety Locks and Locking Units.

Safety catchers are used where protection of personnel and accident prevention must be achieved in connection with raised loads or tools in case of failure of load-bearing machine parts. This may be a leakage or breakdown, for example, ofa hydraulic or pneumatic pressure system. Safety catchers catch falling masses infinitely-variably at any position ofthe stroke, in a mechanically secure and absolutely reliable manner. The design principle ofthe self-rein­forcing clamping ensures an extremely high safety level.

Like safety catchers, rod safety locks are used to safely hold raised loads. However,in contrast to safety catchers, safety locks are not suitable for braking falling masses and absorbing their kinetic energy. On the other hand, generating the full holding force does require only a very short distance; which means a Safety Lock can also be used to fix the position ofa load. The design concept also allows relatively small rod diameters (smaller than with safety catchers) and at a favourable price.

The most recent development from SITEMA guarantees the highest level of safety on inclined and vertical axes: the safety brake type KSP. It is not only suitable for statically holding a vertically moving mass against gravity, but can act as an emergency brake for a free-falling machine axis. The braking action is powerful, but there is also a well-defined upper limit for the force. Typical areas of use are on inclined and vertical axes of handling devices (loading gantries) or machine tools.

In contrast to safety catchers, locking units can hold forces in eitheraxial direction ofthe rod. They therefore allow mechanical interlocking and precise positioning in a wide range of machine and plant components. The clamping with the majority oftypes is engaged by means of spring force, while hydraulic or pneumatic pressure is needed to release the locking device. Rods of 10 to 250 mm in diameter can be clamped, with clamping forces of up to 1500 kN (corresponding to 150 tonnes), depending on the type and size of the device.