Patent Application
20160082322
A traditional golf course covers a distance ranging from about 6,000 to 7,500 yards, or about 3.4 to 4.25 miles, and includes a series of eighteen holes (each ranging in distance from 210-690 yards). A good, experienced golfer (often a professional) can often complete such a course with 72 shots or less because a golf ball is designed to travel far when hit properly. For example, a golf ball is typically very hard and its surface is covered with small, shallow dimples. The hardness of the ball helps the ball convert much of the club head's kinetic energy (primarily the speed at which the club head travels just before impact with the ball) into the ball's kinetic energy (primarily the speed at which the ball travels just after contact with the club head). The small, shallow dimples reduce the air's drag on the ball as the ball travels through the air by tripping the boundary layer of the air flowing over the surface of the ball.
Most golfers, however, cannot complete a traditional golf course with 72 shots or less. Most golfers require significantly more shots because a golf ball that is not hit properly often travels a long distance in the wrong direction. Thus, most courses cover a large area of real estate to accommodate less accurate shots, and most golfers travel about 1.5 times the listed distance of the golf course because they rarely walk straight from each hole's tee to each hole's corresponding green.
To get better, many golfers spend countless hours practicing their swing. Because a regular golf ball travels far when properly hit, golfers can't practice their swing in most urban parks and often go to a driving range that covers a large area to accommodate the long distances that a regular golf ball travels.
To help reduce the size of a golf course and the distance traveled by the average golfer, and to help reduce the size of a driving range, some practice golf balls are designed to travel less distance while in flight compared to a regular golf ball. For example, some golf balls have a smooth surface that significantly increases the air's drag on the golf ball, and some golf balls are softer than a regular golf ball so that less of the club head's kinetic energy is transferred to the ball. Unfortunately, though, these limited-flight golf balls do not provide the same, exciting feel and experience to the golfer as would a regular golf ball when hit properly. The smooth surface of a golf ball adversely affects other flight characteristics of the ball, not just flight distance. And the softness of a golf ball adversely affects the crisp feel of a well hit ball.
In an aspect of the invention, a ball comprises a core and a surface that covers the core. The surface includes at least one groove having a depth, a length and a width, wherein the length of the groove is at least three times the width, and wherein the length of the groove extends at most fifty degrees across the surface of the ball. When the ball travels through the air, the groove trips and obstructs the flow of air across the ball's surface, increasing the air's drag on the ball. This increase in drag causes the ball to not travel as far as a regular ball when hit, and opposes any spin imparted to the ball when hit.
If the ball is a golf ball, the core may be similar to the core of a regular golf ball to provide the same hardness, and thus the same feel when the ball is hit, while the groove of the surface increases the drag on the golf ball and thus reduces the distance that the golf ball travels in flight. In addition, the surface of the ball generates a sound that mimics a whistle while air flows across the surface to warn others of the ball's flight.
In another aspect of the invention, a cover that can be mounted releasably or fixedly on a ball comprises a body configured to cover a region of the ball. The body has a surface that includes a groove having a depth, a length and a width, wherein the length of the groove is at least three times the width, and wherein the length of the groove extends at most fifty degrees across the surface of the body when the body covers a region of the ball. By covering a region of a ball with the cover, one can reduce the distance that the ball travels when in flight, and one can thus convert any desired ball, such as a baseball, golf ball, and/or softball into a limited-flight ball.
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When the ball 10 is in flight, the groove 14 trips and obstructs the flow of air across the ball's surface, increasing the air's drag on the ball 10. This increase in drag causes the ball 10 not to travel as far as it would without the groove 14. If the ball 10 is a golf ball, then the reduced distance that the ball 10 travels in flight allows one to play golf on a shorter course that does not require walking about 5 to 6.5 miles to complete 18 holes, and/or allows one to practice one's swing in a smaller area. If the ball 10 is a baseball, then the reduced distance allows one to play on a smaller field without the use of a fence or net to confine the ball's flight. The groove 14 also opposes any spin imparted to the ball 10 when hit, which also affects the distance the ball 10 travels in flight.
The surface 12 of the ball 10 may include any desired number of grooves 14 arranged in any desired pattern. For example, in this and other embodiments, the surface 12 includes a plurality of grooves 14 that, together, cover the surface 12 of the ball 10 and are arranged as shown in
In addition, although each of the grooves 14 shown in
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In this and other embodiments, the groove 14 is defined by four walls 16a, 16b, 16c and 16d that lie perpendicular to each other to form a rectangular groove 14. Moreover, each wall's surface that is exposed to the interior of the groove 14 is convex when viewed from within the groove 14. In other embodiments, the groove 14 may be defined by a single, continuous, curved wall 16 whose end joins with its beginning to form a curved groove such as a circular, elliptical or oblong groove. In addition, the groove 14 may be defined by three walls 16 that intersect each other to form a triangular groove 14. Moreover, one or more of the walls 16 may include a concave or flat interior surface when viewed from within the groove 14. In still other embodiments, the wall 16 may be flattened or may come to a point, and may include ridges to further interact with air when the ball 10 (not shown) travels in flight.
The floor 18 of the groove 14 may also be configured as desired. For example, in this and other embodiments, the floor 18 is rectangular in shape and substantially smooth with a convex curvature that mimics the curvature of the ball 10 (
In this and other embodiments, the length 20 of the groove 14 is the distance from the interior surface of the wall 16a to the interior surface of the wall 16c. The width 22 of the groove 14 is the distance from the interior surface of the wall 16d to the interior surface of the wall 16b. And, the depth 24 is the distance from the plane defined by the tops of each of the walls 16a-16d to the floor 18.
Each of the length 20, the width 22, and the depth 24, may be any desired dimension that causes the surface 12 of a ball 10 having the groove 14 to trip and obstruct the flow of air across the surface 12 to increase the air's drag on the ball 10. For example, in this and other embodiments, the depth 24 is at least 0.5 millimeters, and the length 20 is at least three times the width 22 and extends at most fifty degrees across the surface 12. Fifty degrees is the angle θ measured at the center 26 of the ball 10. The angle θ is defined by the intersection of two lines 27 and 28 at the ball's center 26 with line 27 passing through the wall 16a and line 28 passing through the wall 16c. More specifically, for the ball 10, several of the grooves 14 extend up to 47 degrees (about 16 millimeters) across the surface 12, while other grooves 14 extend up to 25 degrees (about 9 millimeters) across the surface 12. And for each of the grooves 14, the depth is about 2 millimeters (mm) and the width is about 2 millimeters (mm).
Other embodiments are possible. For example, the length 20 of the groove 14 may be less than three times the width 22, and the depth 24 may be more or less than two millimeters. For another example, a plurality of grooves 14 may include grooves 14 having different depths—the depth 24 of some grooves 14 may be substantially two millimeters (mm) and the depth 24 of other grooves 14 may be substantially three millimeters (mm). For another example, such as a ball 10 that is a baseball, the depth 24 of the groove 14 may be at least 5 millimeters (mm).
The core 30 may include any desired material arranged in any desired manner that provides a desired hardness. For example, in this and other embodiments, the core 30 is a solid body that includes polybutadiene, a high resiliency rubber composition that may or may not include small pieces of metal, such as tungsten or titanium, distributed throughout the core 30. In other embodiments, the core 30 may include a small, rubber body surrounded by a layer of a different material, such as an elastic material wound around the small body. In such embodiments the small rubber body may be solid or hollow; and if hollow, the body may or may not hold a liquid.
Other embodiments are possible. For example, if the ball 10 is a baseball, then the core 30 may include a rubber or cork body that is wrapped in yarn or string.
In this and other embodiments, the pattern 13 includes two symmetrical halves 13a and 13b as shown on surface halves 12a and 12b, respectively. Each of the symmetrical halves 13a and 13b of the pattern 13 includes eight grooves 14a-14h (labeled only on pattern half 13a for clarity) arranged in a square. The eight grooves 14a-14h are arranged in alternating pairs, with grooves 14a, 14b, 14e, and 14f disposed longitudinally on the surface 12a of the ball, and grooves 14c, 14d, 14h, and 14g disposed laterally on the surface 12a of the ball. Each of the two symmetrical halves of the pattern 13a and 13b also includes sixteen additional grooves 14 disposed longitudinally across the surface 12 of the ball 10; here only three grooves 14i-14k are labeled for clarity. Arranged in this pattern, the grooves 14 significantly increase the air's drag on the ball 10 when the ball travels through the air, which in turn significantly reduces the distance that the ball 10 travels through the air.
Other patterns 13 are possible. For example, see the patterns shown in and discussed in conjunction with
In this and other embodiments, the groove 57 does not include a floor in the body 55 of the cover 50. The floor is formed by the outer surface of the ball after the cover 50 is mounted to the ball. In other embodiments, the groove 57 does include a floor in the body 55 of the cover 50.
The cover 50 may be releasably mounted to a ball in any desired manner. For example, in this and other embodiments the body 55 of the cover 50 includes an opening 58 that one inserts the ball through to surround the ball with the cover 50. In such embodiments, the opening 58 may be a slit, and the body 55 may be elastic and sized to exert a compressive force on the ball when the cover 50 is mounted to the ball. In other embodiments, the body 55 may not be elastic and the opening 58 may be larger and include any desired fastening mechanism (not shown), such as Velcro® and/or laces to keep the cover 50 on the ball after the ball is hit.
The cover 50 may be configured to cover any desired portion of a ball. For example, in this and other embodiments, the cover 50 surrounds the ball. In other embodiments, however, the cover 50 may cover a region or a portion of a ball, such as half, three quarters or one third of the whole surface of the ball.
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The preceding discussion is presented to enable a person skilled in the art to make and use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
