Patent ID: 8635813

Claim:
A retractable roof system ( 30 ) for a large building structure ( 32 ) for selectively closing off an opening ( 39 ) of a fixed roof ( 34 ) of the building structure ( 32 ), said retractable roof system ( 30 ) comprising: a roof structure for covering the opening ( 39 ) and having at least one roof section ( 40 ); at least one self-supporting structural pier ( 42 ) for supporting a corresponding said at least one roof section ( 40 ); a deployment mechanism ( 46 ) having a roof connecting part ( 44 ) slidably mounting along a horizontal top section ( 50 ) of the corresponding said at least one pier ( 42 ) and connecting to a respective said at least one roof section ( 40 ), said deployment mechanism ( 46 ) allowing translational displacement of each said at least one roof section ( 40 ) along corresponding said at least one pier ( 42 ), while being supported thereby, between a deployed position in which said at least one roof section ( 40 ) closes off a corresponding portion of the opening ( 39 ), and a retracted position in which the corresponding portion of the opening ( 39 ) is uncovered with said at least one roof section ( 40 ) being generally located in vertical alignment with at least a portion of the fixed roof ( 34 ); the deployment mechanism ( 46 ) further including a system of ropes ( 66 ) and pulleys ( 68 ) and an actuating element adapted to effect anchoring of said at least one roof section ( 40 ) in a respective position thereof, the actuating element being fluid operable and comprising at least one cylinder ( 62 ) in which there is slidably disposed a weight in the form of a piston ( 60 ) on which a fluid is operable; wherein the piston ( 60 ) is of such dimension as to require a low-pressure fluid to effect requisite movement for said at least one roof section ( 40 ) to move, the application or removal of fluid pressure occasioning the necessary movement; and wherein the pulleys ( 68 ) are suitably arranged on the top section ( 50 ) of the at least one pier ( 42 ) at an inner end and an outer end thereof, and the ropes ( 66 ) extend from the piston ( 60 ) and are securely anchored to the roof connecting part ( 44 ) of the top section ( 50 ) of said at least one pier ( 42 ) whereupon in use movement of the ropes ( 66 ) causes translational movement of the roof connecting part ( 44 ).