Patent ID: 9353783
Filing Date: 2016-05-31
CPC Classification: B23P,F16B,Y10T

Claim Text:
1. A hollow pin comprising: a hollow body having an outside surface, a thickness, a length, two axial ends, and an axially extending internal bore, the hollow body having an outside diameter that is substantially circular shaped and an inside diameter, and the hollow body defining a plurality of voids extending through the thickness of the hollow body from the outside diameter to the inside diameter; wherein the plurality of voids have an ellipse pattern having an ellipse shape that is different on the outside diameter than on the inside diameter; wherein the ellipse pattern includes axial ellipses and circumferential ellipses, and wherein the axial ellipses each have a smaller short axis and larger long axis on the inside diameter than on the outside diameter, and the circumferential ellipses each have a larger short axis and a shorter long axis on the inside diameter than on the outside diameter; wherein said plurality of voids are distributed over the entire circumference of the hollow body for the entire axial length of the hollow body; and wherein the plurality of voids provide the hollow body with auxetic properties, such that a compressive axial load applied to the axial ends causes lateral contraction of the outside diameter of the hollow body towards an axis of the internal bore.