(57) A mechanism for the controlled retracting movement of a roller insect-blocking foil
means. The mechanism comprises wear-free, reliable components and is of simple construction
and assembly, incorporating means for selective activation thereof in the retracting,
rolling up direction of movement of the roller insect-blocking foil means (1) only.
The mechanism consists in the connection of the drum (8) moving under the action of
resilient spring means during rolling up of the insect-blocking foil means (1) to
a shaft means (9) moving within a chamber (7) incorporating a relatively viscosity
independent chamber filling medium to effect a frictionally enhanced and constantly
acting movement of the retarding mechanism. The filling medium is either a malleable
solid substance or a fluid means acting in association with an arrangement of diaphragms
(12) being provided with a plurality of perforations (12a) for selectively allowing
passage of the fluid means.
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