Smart Net
Disclosed is an apparatus comprising a set of molded plastic sections, assembled to form an improved tennis ball returner. It is suited to rest at the bottom of a tennis net, on either side. It is parabolically shaped, so as to return tennis balls toward the center of the tennis court baseline. The exposed surface is also curved, so that it converts a maximum of energy in the falling tennis ball into angular momentum.
This application claims priority of U.S. Provisional Patent Application No. 61/214,157 to Zoran Stoyanovich, having the filing date of Apr. 21, 2009.
BACKGROUNDIn the game and practice of Tennis, the tennis balls often get stopped by the net. Since the net is substantially resilient, many balls tend to drop straight down and come to rest at the base of the net. That is, when the net catches a ball, the horizontal velocity of the ball is neutralized by the net, and the ball is allowed to drop to the ground from its height at the net. The energy of the ball, as it drops to the base of the net, can be utilized to redirect the ball back to the player. However, this available energy is normally wasted or under-utilized.
When it comes to practicing strokes or serves in tennis, it is considered a necessity to use a great number of tennis balls. This is so that more practicing is accomplished before the participants must stop to collect the balls. When there are more balls near the participant during practice and play, less time is spent collecting balls from further away. Anything that helps to deliver tennis balls to the participants reduces the amount of time spent retrieving balls, and makes the game more enjoyable. In match play, ball-retrieval can also make the game more accessible to others, by making the tennis court available sooner, for the next group of players.
During typical tennis matches, incidentally, most players prefer to use NEW tennis balls from freshly-opened pressurized containers. This is presumably because tennis balls will gradually lose their internal pressure by gas diffusion, when they are exposed to a lower pressure (such as atmospheric pressure) for more than a few hours. Tennis balls will lose their internal pressure from repetitive hitting, too. New balls also have a plush and unworn felt surface, which allows a better performance that is enjoyed by most players. Because of these factors, most tennis players prefer to use new balls whenever possible. And, since most players purchase their own tennis balls, and carry them during play, there are normally only 3-6 balls available for play on the court, at any given time.
Tennis balls are normally allowed to come to rest at the net, where they must be retrieved during practice or play. Sometimes, a ball comes to rest as much as a few feet away from the net, and remains there during competitive play. This is because players would rather continue the match, than to interrupt play to retrieve the earlier-played ball. They do this, particularly in singles play, hoping that they will not be drawn near the earlier ball during the following point(s). This condition sets up a risk of injury, and a risk that probably should be avoided whenever possible.
Some products have attempted to mitigate this problem by providing an angled surface at the base of the net, to deflect balls that are caught and dropped by the net, back toward the baseline. U.S. Pat. No. 4,971,319 to Cutrone discloses just such an attempt. However, the construction specified in that document does not function reliably. The angled flexible surface that Cutrone discloses unfortunately absorbs too much of the energy possessed by a falling tennis ball. It only serves to make the problem worse, by making it more likely that balls will come to rest in the service court.
Furthermore, because the deflecting surface in the Cutrone document is specified as being flat, it causes the ball ITSELF to absorb much of the impact energy—energy that could otherwise be used to redirect the ball further toward the baseline. This defeats its own purpose even more-so.
And, finally, because the deflecting surface in the Cutrone document is noted as being specifically parallel to the length of the tennis net, it is more likely to deflect balls to the OPPOSITE side of the court and AWAY from the player, than it is likely to direct balls toward the player.
SUMMARYDisclosed is an improved tennis ball returner, which remedies the mentioned problems more effectively than its predecessors do. This invention is a solid, curved, tapered ramp that runs the entire length of the tennis net, on either side. It effectively maximizes the conversion of vertical velocity into horizontal velocity, while keeping energy losses to a minimum. It is shaped so as to re-direct most balls toward the middle of the baseline. It may be a permanent fixture on the court, or it may be assembled and dis-assembled for each use.
When a tennis ball is stopped in flight by the net, it will tend to drop down onto the Smart Net and begin to roll toward the baseline. The Smart Net comprises an elongated complex-curved surface that causes the ball to roll, as opposed to bounce. This tendency to roll, based on the design of the Smart Net, causes the kinetic energy of the moving ball to be conserved. The kinetic energy is simply transformed from translational motion into spinning (rolling) motion.
This is much different than a situation where some angled flat-panel surface causes a tennis ball to bounce off at some new trajectory. When a ball bounces, it loses a great deal of kinetic energy (motion), as that energy is actually converted into heat. Consider two identical balls that are dropped from the same height, where one is dropped onto an angled, floppy, flat panel, and the other is dropped onto a firm, curved guide surface. The ball dropped onto the firm, curved guide surface will travel (roll) much further than the other ball, before coming to rest.
FOR CLARITY: The mesh of the tennis net is not shown in any of the figures.
FOR CONVENTION: The sides of the net are parallel to the baselines of the full court (i.e. the opponents play on opposite sides of the net), and the ends of the net are at the side boundaries of the full court.
FOR CONVENTION: The sides of the net are parallel to the baselines of the full court (i.e. the opponents play on opposite sides of the net), and the ends of the net are at the side boundaries of the full court.
The invention comprises two sets of nine nestable sections of plastic, in the preferred embodiment. It also comprises a set of eight connecting clips. When assembled, the Smart Net is symmetric about the center strap of the net. The complete Smart Net runs along both sides of the net, to service a full tennis court. However, one half of the complete invention can be used to service one end of the court, for training or practice.
The parts are molded out of a suitable plastic to be essentially rigid.
Each of the nine sections is shaped uniquely. Yet, they are shaped so that they are stackable. When assembled, they form a curved parabolic surface that rolls tennis balls toward the center of the baseline, where at least one player tends to be situated.
The Smart Net extends from one net pole to the other, so that it may also catch balls headed out of bounds.
The drawing figure is as a visual rep of the Smart Net. Different degrees of taper, as well as varying heights, may be made available, depending on the playing surfaces, to optimize the rollback to the baseline.
Claims
1. an improved tennis ball returner comprising a set of sections having a curved surface and a set of connecting clips, wherein said returner directs tennis balls retained by a tennis net toward the center of a tennis court baseline.
2. The returner in claim 1, wherein said curved surface comprises a firm material so that it minimizes the absorption of energy from said tennis balls.
Type: Application
Filed: Apr 20, 2010
Publication Date: Oct 21, 2010
Inventor: Zoran Stoyanovich (Chicago, IL)
Application Number: 12/763,851