| 主权项 |
1. A collar, comprising: a first end and a second end opposite the first end, a longitudinal axis extending from the first end to the second end, and a shank extending from the first end to the second end and including an interior surface and an exterior surface, wherein the interior surface of the shank includes a first interior surface extending from the first end to a first interior inflection point, a second interior surface extending from the first interior inflection point to a second interior inflection point, and a third interior surface extending from the second interior inflection point to the second end, wherein the exterior surface of the shank includes a first exterior surface extending from the first end to a first exterior inflection point, and a curvilinear exterior surface extending from the first exterior inflection point to a second exterior inflection point, and wherein the curvilinear exterior surface and an imaginary line extending from the first exterior inflection point to the second exterior inflection point form a first area that is sized and shaped to receive forward extrusion of the collar as the collar is being installed. |
