| 摘要 |
The stretcher frame, especially of lightweight metal, consists e.g. of four side-members (9d) covered by a supple sheet material (3) such as a plastic-coated fabric fastened at the back of the frame. The material is held under tension and fixed by means of projecting strips with slots (17) running along the back of the frame members, and U-section capping strips (7). The two sides (19a, 19b) of the projecting strips and the inner surfaces of the capping strips have ribs (11a) that grip the supple sheet material when it is drawn over the projections and the capping strips fix it in place.
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