| 发明名称 |
APPARATUS AND METHOD FOR PERFORATING ROOFING SHEET MATERIAL |
| 摘要 |
<p>The apparatus of the present invention comprises at least one hole-punching device operated by a pneumatic cylinder for driving a punch rod through the peripheral surface and radially to the center of a roll of roofing sheet material. The method of the invention provides for the steps of preparing the sheet roofing material, winding the sheet into a roll, and punching a plurality of perforation holes in the roll from the surface to the center thereof.</p> |
| 申请公布号 |
CA1037376(A) |
申请公布日期 |
1978.08.29 |
| 申请号 |
CA19760243741 |
申请日期 |
1976.01.19 |
| 申请人 |
G A F CORPORATION |
发明人 |
DAVIS, DUANE A.;KRENICK, MICHAEL P. |
| 分类号 |
B23B35/00;B26F1/02;(IPC1-7):26F1/02 |
主分类号 |
B23B35/00 |
| 代理机构 |
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