June 9, 2009
Sitema has introduced a safety catcher that stops and locks dropping platens on hydraulic presses and other machines.
The load is secured by stopping the dropping mass using the weight as a means to wedge the safety catcher against the acting hydraulic cylinder rod or a separate catcher rod. The locking capability is proportioned to the dropping mass: the heavier the dropping mass, the stronger the grip.
The locking position functions for the entire stroke of the machine, which helps ensure a safety stop at any stroke position. Depending on the device type, the locking system is held open by either hydraulic or pneumatic pressure. Whenever the pressure drops, the safety catcher is set to automatically secure any dropping load.
The full locking force is created only by the load. The unit will lock only when the safety catcher is in locking position with no hydraulic or pneumatic pressure present, and the load is moving downward, such as when the acting hydraulic cylinder of the press is leaking.
The proximity switches signal "load secured" or "unlocked." They can be used for the machine control.
The safety catchers are certified by the German TV to comply with the DIN EN 693 standard as lift secure devices. Other certifications also are available upon request.