Back to results
US 4,478,268 AGranted
Door structure
AssigneeCopper Cliff Door Manufacturing (1980) Limited
InventorGlenn R. Palmer
Life of this patent
Estimating the term…
Abstract
A door for closing vehicular traffic passages is provided in which the door is a curtain fabricated from a hard flexible material. The curtain runs in opposing channels, is mounted on a counterbalanced wind-up drum and under impact changes weight, moves out of the channels and is wound up to open the vehicular passage.
Claims14
A damage-minimizing door comprising:
- a flexible curtain having an upper end and a lower end and side edges;
- a curtain winding mechanism;
- said upper end of said curtain being secured to said winding mechanism for moving said curtain upwards and downwards;
- a pair of parallel spaced apart guide channels, said side edges of said curtain being movable in said guide channels, being sealingly engageable therewith under at least atmospheric pressure and being releasable therefrom at a predetermined impact force on said curtain;
- and,
- a rigid bar secured adjacent the lower end of said curtain, said rigid bar being releasably secured to said curtain and releasing therefrom at said predetermined impact force.
3 more elements
A damage-minimizing door as claimed in claim:
- 6 wherein said restraining means includes projections extending into a channel defined by said guide channels to provide a throat of reduced dimension relative to said thickened area of said curtain to restrain lateral movement of said curtain.
A damage-minimizing door including:
- a flexible curtain having a first upper end, a second lower end and side edges;
- a curtain winding mechanism, said first end of said curtain being secured to said curtain winding mechanism for moving said curtain upwards and downwards to respectively open and close a doorway;
- a pair of parallel and spaced apart guide channel means each comprising an elongate slot whose mouth faces into said doorway, said side edges being movable upwardly and downwardly in said slot as said curtain is respectively moved up and down;
- said side edges sealingly engaging said channel means when said door is employed in an environment which is at least at atmospheric pressure to normally restrain lateral movement of said side edges through the slot mouth from said guide channel means;
- and,
- said side edges of said flexible curtain being pulled laterally through the slot mouth from said guide channel means when a predetermined impact force is applied to said flexible curtain, causing at the most, negligible damage to said guide channel means and minimal damage to said flexible curtain.
3 more elements
Dependencies are inferred from the claim text.