Automatically controlled roller shutter - has coil spring inside winding drum, tensioned hydraulically during shutter unwinding movement

摘要

During the lowering of the shutter a control device causes a gear wheel to stay in mesh with a toothed rim on a part rigidly connected with the winding drum. The movement of the gear wheel produces an oscillating movement on a lever around its pivotal point and a reciprocating movement of rack driven via gearing. A pump piston reciprocating movement sucks hydraulic fluid from a vessel and pumps it through a pipe into the rear space of a hydraulic cylinder. Consequently a second piston is moved to the left and pushes a screw shaft in the same direction for a coiled spring tensioning. The hoisting of the shutter is actuated by a release push-button.