Patent ID: 9091054
Filing Date: 2015-07-28
Classification: E04B,E04F

Abstract:
1. A membrane element for covering surfaces, comprising a frame and a membrane material stretched thereon, wherein at least one frame region is bent inwardly on account of forces exerted by said membrane material on said frame, wherein the inwardly bent frame region has at least one tightening unit for pulling or pressing said frame region outwardly with respect to an abutment, towards an unbent state and wherein each tightening unit includes a bolted joint to pull bent frame regions toward said abutment, wherein slot nuts are fixed in said frame for said bolted joint, wherein a threaded bolt is present for bolting said slot nuts together, the threaded bolt including a shaft with a pair of opposing threaded side regions and a pair of opposing flattened side regions, wherein the pair of opposing threaded regions are separated from each other by the pair of opposing flattened side regions, and wherein a driving wheel is present in said frame for rotating the threaded bolt to displace the slotted nuts relative to one another, the driving wheel including: a circular disk-shaped plate having an edge region that is rotatably engaged in the frame, a toothed wheel connected to the circular disk-shaped plate, and an opening in the disk-shaped plate and the toothed wheel for receiving the threaded bolt therethrough, the opening having a shape matching the flattened side regions of the shaft of the threaded bolt, such that a rotation of the driving wheel results in a corresponding rotation of the threaded bolt.