GB988867A - Improvements in or relating to a method of controlling and positively driving in either direction a flexible metal or like sheet, and a closing device obtained therefrom - Google Patents

Abstract

988,867. Door operating appliances; shutters. INTERNATIONAL MACGREGOR ORGANIZATION. Nov. 16, 1961 [Dec. 19, 1960; June 22, 1961], No. 41118/61. Headings E1J and E2M. [Also in Division B7] A sliding roof, curtain, door or cover for a building, ship's hold, waggon, truck, or trailer comprising a flexible sheet 1 made of metal or some other resiliently deformable material and adapted to be wound on to, or unwound from, a rotatable drum 2 is characterized in that the winding and unwinding operations are performed solely by means of the thrust exerted on the sheet by the rotation of the drum, this being made possible by employing a drum which is axially grooved or fluted or similarly contoured and by exerting a rolling pressure on the outer turn of the wound sheet in proximity to the generating line at which contact is established between the sheet and the drum, the rolling pressure being applied by one or more freely rotatable members 5 which are placed in pressure contact with the sheet to force the latter to penetrate the hollows on the surface of the drum or on the previous turn of the sheet wound thereon. Preferably the sheet is corrugated and the grooves on the drum match those on the sheet, the members 5 being correspondingly profiled rollers which exert sufficient pressure to produce a simultaneous tensile and flexural elastic deformation of the sheet whereby the angular pitch of the mating corrugations in successive turns of the sheet is maintained constant. Alternatively the members 5 may be circular rollers of elastic material adapted to undergo a temporary elastic deformation to accommodate the corrugations of the sheet. The members 5 are keyed to a shaft 6 freely rotatable in a pair of arms 8 pivotable about a fixed axis 7, and are urged towards the sheet 1 by springs 9 acting on the arms. Alternatively the members 5 may be mounted on pads of resilient material. Adjustable stops 10 limit the movement of the members away from the sheet. The contoured surface of the drum 2 may be formed by permanently securing the first turn of the corrugated sheet 1 to a smooth-surfaced drum, and the drum may be driven by any convenient means, for example a crank 13 and chain 14. Means may be provided to arrest rotation of the drum in the event of the sheet jamming, to prevent permanent damage to the sheet. Slideways 11 in the form of extruded sections 12 guide the sheet to prevent it from buckling, and the crank 13 may be retained in a position corresponding to the unwound state of the sheet by a spring-loaded hook 16. A lock may be provided at the free end of the sheet.