| 摘要 |
Six lobes (22) of a nut have axial surfaces falling on six tangent cylinders (28) of equal radius and having axes lying on a right cylinder concentric (32) with the axis of the nut. The surface of a second concentric right cylinder having a radius (40) greater than the first (36) defines furrows (26) between the lobes. Successive lobes are tangent (42) to an imaginary flat surface and the furrows are spaced away from the surface inside it. |
