Screen assembly

A screen assembly which comprises in combination:

• a screen unit including a hollow screen casing, having a winding spindle coaxially housed within the screen casing and a screen winder operatively associated with the winding spindle, and a screen sheet having one end rigidly secured to the winding spindle within the screen casing and the other end situated outside the screen casing and a frame rod to which said other end is secured;
• means for suspending the screen unit from an overhead support structure;
• means including first and second upright frame members for connecting said screen unit to said suspending means, said first and second upright frame members being spaced from each other to define an accommodation space therebetween;
• a tilt angle adjusting mechanism including a tiltable member and operatively accommodated within said accommodation space for adjustably tilting said tiltable member from an initial position to a maximum tilted position through one or more intermediate tilted positions, said mechanism having a plate means integrally formed with the tiltable member, the plates means having a semi-circular periphery with a plurality of sawteeth thereon equal in number to the number of positions of the tiltable member including the initial position, intermediate tilted positions and the maximum tilted position, a clutch plate of substantially segmental shape having an arcuate peripheral portion and a pair of flanks and including a notch in the arcuate peripheral portion of the clutch plate, and a latch element pivotally supported in position between the first and second upright frame members and urged in one direction, a common shaft on which the plate means and the clutch plate are pivotally mounted, said shaft being mounted between the first and second upright frame members with the arcuate peripheral portion of the clutch plate projecting slightly outwardly from the semicircular periphery of the plate means, the flanks of the clutch plate substantially facing the tiltable member and adapted to receive alternately an external pushing force from the tiltable member, the latch element being positioned for remaining engaged in the notch in the clutch plate during the pivotal movement of the tiltable member from the initial position to the maximum tilted position past the intermediate tilted positions riding over the sawteeth in the plate means with one of the flanks receiving the force from the tiltable member pivoting towards the maximum tilted position and, during return of the tiltable member back towards the initial position, the latch element being disengaged from the notch in the clutch plate and the other of the flanks receives the force from the tiltable member then pivoting towards the initial position, the return of the tiltable member back towards the initial position being initiated after the tiltable member is further pivoted beyond the maximum tilted position;
• a tiltable support bar means including first and second straight sections articulated to each other, one end of the first section remote from the second section being pivotally connected to said tiltable member and one end of the second section remote from the first section being pivotally connected to the frame rod at a position substantially intermediate of the length of the frame rod, said first and second sections of the tiltable support bar means being folded close to each other when and so long as the screen sheet is not drawn out of the screen casing to a stretched position, and being brought into substantial alignment with each other when and so long as the screen sheet is drawn out of the screen casing to the stretched position, said tiltable support bar means being tiltable together with the tiltable member for corresponding tilting the screen sheet substantially about the screen casing, the screen sheet when the tiltable member is in the initial position being in a plane perpendicular to the horizontal datum.