| 摘要 |
The net sheath (1) contains loosely distributed plastics elements (2) and incorporates both floats (12) and ballast (11), to gather oyster spat for oyster farming. The elements are made of plastics sheet, are hollow with an open face, and shaped to prevent one element housing completely in another. Each element has a floor opening (20), together with a wall of a different shape to the remainder, the opening having an internal edge return whilst the constituent sheet thickness is not more than 0.5mm. The floor may have recesses (25-28), of which one (27) has a different shape and the walls have local internal deformation (13,14), the sheath being divided into closed (6-9) sections (3-5). |
