| 摘要 |
A method of making a gasket of the kind wherein at least one aperture is blanked out at a desired location in a metal plate before or after, or at the same time as a peripheral corrugation is formed around the margin of said aperture, is characterized in that said corrugation is formed in the sheet around the intended location of said one aperture after an initial step of forming at least one preliminary aperture at said location, the shape and configuration of said preliminary aperture being selected in accordance with the proximity of the said one aperture to the edges of the plate and to the location of any other intended aperture in the plate, so that the corrugation formed after said preliminary aperture forming step exhibits controlled geometry and plastic deformation when subjected to compression. |
