Sports ball
A sports ball comprises a bladder and a contouring layer surrounding the bladder. The contouring layer includes at least one panel defining a repeating pattern of perforations configured to lower a Poisson's ratio of the contouring layer. Each of said perforations defines a reentrant shape and a constant cross-sectional width in a radial direction of the ball.
1. A ball comprising:
a bladder;
a contouring layer surrounding the bladder, the contouring layer including at least one panel defining a plurality of circumferentially arranged segments and a plurality of apertures configured to lower a Poisson's ratio of the contouring layer, wherein each of said apertures forms a reentrant shape that remains constant extending through the at least one panel in a radial direction of the ball; and
an outer layer covering the contouring layer, the outer layer including a plurality of dimples, each of the plurality of dimples aligned with one of the plurality of apertures.
2. The ball of claim 1 wherein the at least one panel is a perforated sheet defining a repeating pattern of reentrant shapes with each of the apertures formed within one of the reentrant shapes.
3. The ball of claim 1 wherein the outer layer is comprised of a transparent material such that each of the plurality of apertures is visible through the outer layer.
4. The ball of claim 1 wherein the contouring layer is an auxetic structure exhibiting a near zero Poisson's ratio.
5. The ball of claim 1 wherein the at least one panel includes a first t-shaped panel at a first pole of the ball, a second t-shaped panel at a second pole of the ball, and a plurality of equator panels spanning an equator of the ball, each of the equator panels covering a portion of the equator and extending from the first t-shaped panel to the second t-shaped panel.
6. A ball comprising:
a bladder;
a near-auxetic contouring layer surrounding the bladder, the contouring layer including a perforated sheet defining a plurality of apertures that extend through the perforated sheet from one side of the sheet to an opposing side of the sheet, each of the plurality of apertures defined within segments of the contouring layer, the segments having a constant cross-sectional width in a radial direction of the ball; and
an outer layer surrounding the contouring layer, the outer layer including a plurality of dimples, each of the plurality of dimples aligned with one of the plurality of apertures such that a position of each of the plurality of apertures is tactilely detectable via the outer layer.
7. The ball of claim 6 wherein the plurality of segments defines a repeating pattern of reentrant shapes with each of the apertures formed within one of the reentrant shapes, and wherein each of said apertures extends through the perforated sheet such that the contouring layer has a constant cross-sectional shape in a radial direction of the ball.
8. The ball of claim 6 wherein the outer layer is comprised of a transparent material such that each of the plurality of apertures is visible through the outer layer.
9. The ball of claim 6 wherein the contouring layer exhibits a Poisson's ratio of less than 0.15.
10. The ball of claim 6 wherein the contouring layer includes a first t-shaped panel at a first pole of the ball, a second t-shaped panel at a second pole of the ball, and a plurality of equator panels spanning an equator of the ball, each of the equator panels covering a portion of the equator and extending from the first t-shaped panel to the second t-shaped panel.