Door which can be rolled up

Claim 1

A roll-up door means, in combination comprising: a hanging door having a mass weight with a free end which can be rolled up as well as unwound and including a winding tube having two ends, one of said ends having a first inside-arranged spring receiving means mounted on a winding shaft for winding up and unwinding said hanging door for opening and closing-off an opening the other of said ends having a second inside-arranged spring receiving means connecting a pretensioned spring means relative to a fixed shaft for balance of the mass weight of said hanging door, said second spring receiving means being rotatably mounted on said fixed shaft being disposed between said second spring receiving means and said fixed shaft is said pretensioned spring means, a tensioning mechanism, being disposed between the free end of said hanging door and said winding tube, said winding tube also including therewith traction members which are guided about guide pulleys; said traction members being fixed with one end on said free end of said door and with the other end on said tensioning mechanism which comprises: tensioning pulleys which are freely rotatably mounted at both ends of said winding tube; and pretensioned leg springs respectively disposed between each of said tensioning pulleys and said winding tube; said ends of said winding tube being axially recessed at each end thereof; and said leg springs being disposed in said axial recesses of said winding tube so that no additional casing is required, said leg springs being subjected only to bending stresses particularly for long service life and no risk to safety.