| 摘要 |
Foam rubber from which are cut cushions of the desired contour has uniformly spaced corings 18, 19 extending inwardly from broadside top and bottom faces 16, 17 part way through the thickness of the rubber, the corings having a maximum diameter between 1/8 and inch and the area of the perforations being between 2 and 20%. Specifications 619,619, <PICT:0882956/IV (a)/1> 668,945 and U.S. Specification 2,310,830 are referred to. |
