Tennis ball having a core with aerodynamic patterns
A tennis ball comprises a hollow elastic circumferential core defining a primary outer surface pattern, and a textile outer layer extending over and about the core.
1. A tennis ball comprising:
a hollow elastic circumferential core; and
a textile outer layer extending over and about the core; and
a plurality of recesses, wherein each of the plurality of recesses directly underlies and is covered by the textile outer layer so as to be sandwiched between the hollow elastic circumferential core and the textile outer layer, wherein the recesses permit airflow within and through each individual recess of the recesses to reduce drag of the tennis ball.
2. The tennis ball of claim 1 , wherein the plurality of recesses are a plurality of circular dimples.
3. The tennis ball of claim 2 , wherein the plurality of dimples are arranged in a symmetrical pattern about the core.
4. The tennis ball of claim 1 , wherein the plurality of recesses are a plurality of channels.
5. The tennis ball of claim 4 , wherein the plurality of channels are spaced apart from each other.
6. The tennis ball of claim 1 , wherein the plurality of recesses are selected from the group consisting of: hemi-spherically shaped dimples, semi-oval shaped recesses, cuboid shaped recesses, pyramid shaped recesses, channels having a U-shaped cross-sectional shape, channels having a V-shaped cross-sectional shape, channels having a rectangular cross-sectional shape and combinations thereof.
7. The tennis ball of claim 1 , wherein an outer surface of the outer layer includes a primary outer surface pattern including the recesses and a secondary outer surface pattern that corresponds to the primary outer surface pattern of the core.
8. The tennis ball of claim 1 , wherein the core has a spherical outer surface defining the primary outer surface pattern, the outer surface having raised portions and depressed portions amongst the raised portions, the textile layer extending over the depressed portions of the outer surface.
9. The tennis ball of claim 8 , wherein the raised portions comprise individual protuberances rising above the depressed portions.
10. The tennis ball of claim 8 , wherein the depressed portions comprise dimples, and wherein the raised portions comprise those regions of the outer surface between the dimples.
11. The tennis ball of claim 8 , when the depressed portions comprise grooves, and wherein the raised portions comprise those regions of the outer surface between the grooves.
12. The tennis ball of claim 8 , wherein the hollow elastic core comprises two joined semi spherical halves.
13. The tennis ball of claim 1 , wherein the textile outer layer is a woven felt.
14. The tennis ball of claim 13 , wherein when tested with a test setup including a ball velocity of 75 mph, a 5.5 degree launch angle and a spin rate of 1800 rpm, the tennis ball exhibits a coefficient of drag less than 0.6.
15. The tennis ball of claim 1 , wherein the textile outer layer is a needle-punch felt.
16. The tennis ball of claim 15 , wherein when tested with a test setup including a ball velocity of 75 mph, a 5.5 degree launch angle and a spin rate of 1800 rpm, the tennis ball exhibits a coefficient of drag less than 0.55.
17. The tennis ball of claim 1 , wherein the core has a wall thickness within the range of 3.0 to 5.2 mm.
18. A tennis ball comprising:
a hollow elastic circumferential core defining a primary outer surface pattern; and
a textile outer layer extending over and about the core, wherein the surface pattern includes a plurality of recesses and wherein the plurality of recesses are a plurality of dimples, wherein each of the plurality of dimples is covered by the textile outer layer so as to form an empty void within each of the dimples and sandwiched between the core and an inner radial surface of the textile outer layer.
19. The tennis ball of claim 1 , wherein the textile outer layer at least partially fills the recesses, the textile outer layer facilitating airflow therethrough, through and across each individual recess.
20. The tennis ball of claim 1 , wherein the recesses are unfilled and empty, forming empty voids across and through which air may flow to reduce drag of the tennis ball.
21. A tennis ball comprising:
a hollow elastic circumferential core defining a primary outer surface pattern; and
a textile outer layer extending over and about the core, wherein the surface pattern includes a plurality of recesses, wherein each of the plurality of recesses directly underlies and is covered by the textile outer layer so as to be sandwiched between the hollow elastic circumferential core and the textile outer layer and wherein the plurality of recesses define a plurality of voids formed between the outer layer and the core.