Automatic locking device Insulation against cold and noise
The shutter is suspended with SIRAL-safety and insulations springs (not with straps)
The springs push the shutter to rear side of the box and close the gap. Insulation against cold and noise
If lifted from outside the shutter blocks in the locking hooks.
pulvercoated abarasion-safe (to mark K when ordering).
Important for installation
The spring tension holds the shutter in vertical position, therefor the shutter locks at the upper corner. The tension has to be stronger than the force of the strap coiler. This is accomplished by the right type and number of springs.
recomendation: every 30 cm = 1 spring
The shutter should reach about 20 mm beneath the upper box corner.