| 摘要 |
965,912. Fishing. RHEINSTAHL HUTTENWERKE A.G. Feb. 10, 1961 [Feb. 11, 1960], No. 5084/61. Heading A1A. A ground-line ball for trawl nets comprises two hemispherical shells 1, 2 welded together and formed with troughs 7 defining a raised portion 8 covered by a tread 10 of rubber or synthetic plastic. Reinforcing rings 9 welded in the troughs protect the edges of the tread 10. The tread 10 may be vulcanized or cemented to the ball, or protruberances on the raised portion 8 of the ball may engage indentations in the inner surface of the tread. In a modification the troughs 7 accommodate bended edges on the tread 10 and no reinforcing rings are provided. |
