摘要 |
Two sheets of deformable material are securely fastened together without the use of adhesives, separate rivets or fasteners by forming a closed end cylindrical projection on the upper surface of the first sheet, placing the second sheet having an aperture over the first sheet, the aperture receiving the projection, and deforming the projection in the aperture to produce a tight friction fit and form a lip which overlaps the exterior rim of the aperture to limit its enlargement. In a preferred embodiment two plates are fastened together to form a rotor by striking the projection with a die having an annular groove forcing one part of the projection into the aperture and forming another part of the projection into the lip.
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