| 摘要 |
<p>The frame (1) has a frame part (2) comprising a stringer (3) for fastening a flexible sheet (4) in a canvas (41). An extendable hooking unit is fixed at a periphery of the canvas. The extendable hooking unit is attached with the stringer for fixing the flexible sheet on the frame part. The stringer comprises an external flange. An inner core extends from the external flange toward interior of the frame part. An internal flange is provided at a free end of the inner core.</p> |
