Roll shutter for hinged-casement type roof windows

A roll shutter for a hinged casement type roof window, comprising:

• a shutter frame;
• a winding shaft arranged in the frame which supports a wound portion of the roll shutter plating;
• two guide rails connected to the shutter frame parallel to each other, each forming a guide groove for the ends of the shutter and are divided at equal distances by the shutter frame, whereby the upper sections of the guide rails connected to the roll shutter frame are connected with the lower sections by respective hinges, the pivot axes of which run parallel to the pivot axis of the hinged casement;
• a cross rail connecting the lower sections with each other at their ends opposite the shutter frame;
• a roll shutter activation device having a first and a second control cable, which are connected to the lower end of the roll shutter at equal distances from the center of the roll shutter and each of which runs in one of the two guide grooves in the guide rails and past diverting elements provided in the area of the cross rail and through a bore in the frame of the hinged casement and are connected with one end of an activation loop which can be grasped by the user, a third control cable being connected to the other end of the activation loop, said third control cable passing through a bore in the frame in the hinged casement, with the winding shaft, a spool onto which the end of this third control cable is wound, said spool being fixed to the winding shaft;
• wherein in the area of the cross rail, first and second loop-forming rollers are provided in addition to the diverting elements, which rollers serve to form a buffer loop, the loop length of which is at least as large as the displacement path of the roller shutter between the entirely closed and entirely opened positions, and wherein the lengths of the first and second control cables attached to the lower end of the roll shutter are selected such that their connection point, at which they are attached to each other and are connected with the third control cable running to the spool, is located within the buffer loop when the roll shutter is completely open and completely closed and;
• wherein said diverting elements are located within said guide rails at opposite sides of said frame, said first and second loop-forming rollers are located at opposite sides of said frame, and said connection point is free to move within said buffer loop to any point between one of the diverting elements and the loop-forming roller located on the same side of the frame, passing over the loop-forming roller located on the opposite side of the frame, as the roll shutter is completely opened and completely closed.