Adjustable tensioning arrangement for modular security door system
OwnerHarry E. Finch, Geza J. Szayerinventors
Life of this patent
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Abstract
An adjustable tensioning arrangement for modular security door systems has modular components interchangeable for use on either side of the door system, thereby reducing significantly the number of parts which must be manufactured for the door. The adjustable tensioning arrangement is capable of accommodating a variety of tensions desired by individual users. The adjustable tensioning arrangement may be produced with a minimal number of required parts, and at very low cost. Construction of the adjustable tensioning arrangement may incorporate readily fabricated steel components, or utilize injection molded or other plastic type materials.
Claims14
A roll-up door system for mounting in a door opening, said door system comprising:
- vertical guide members mountable along side edges of said door opening for guiding the edges of said door as it is raised and lowered;
- a pair of plate support brackets for installation at the top of said vertical guide members in positions extending above the top edge of the door opening;
- a pair of support plates for mounting onto said plate support brackets in positions extending inwardly from the top of the door opening;
- a barrel assembly mounted for rotation about a central axle adapted to rotatably engage said support plates;
- and
- a roll-up door mounted to said barrel assembly for rolling thereabout as the door is raised;
- said barrel assembly including rotational tensioning means incorporating a spiral torsion spring anchored at one end to said axle for balancing the forces required to raise and lower said door;
- an adjustable tensioning body for selectively modifying the torsional force provided by said torsion spring when said system is installed to cover said door opening with opposite ends of said axle extending through circular openings in said support plates, said adjustable tensioning body having an extended sleeve portion with a central bore for receiving one end of said axle therein and a circular bearing surface for mounting within said circular opening;
- means for adjustably attaching said body to said first support plate in a selected angular position with respect to said circular opening;
- and
- means for attaching said body to said torsion spring to control the tension of said torsion spring by rotating said body relative to said first support plate.
Dependencies are inferred from the claim text.