US20100267494A1

US20100267494A1 - Smart Net

Info

Publication number: US20100267494A1
Application number: US12/763,851
Authority: US
Inventors: Zoran Stoyanovich
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-04-21
Filing date: 2010-04-20
Publication date: 2010-10-21

Abstract

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.

Description

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.

BACKGROUND

In 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.

SUMMARY

Disclosed 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.

DRAWING VIEWS

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.

FIG. 1 is a full perspective view of the invention, shown at the net of a typical tennis court.

FIG. 1 a is a full perspective view of one section of the invention, as seen from below.

FIG. 1 b is a full perspective view of a connecting clip.

FIG. 2 is a full perspective view of a set of sections of the invention, shown nested in a double-stacked configuration. This double-stack of components makes up one half of the invention, to service one side of the net (i.e. one end of a full tennis court). Another double-stack is required to complete the entire tennis court.

FIG. 2 b is a portion of a perspective view of one end of the net, showing one double-stack nearby, prior to installation, and a portion of another half of the invention already assembled on the other side of the net.

FIG. 3 shows a portion of a perspective view of the net, where a first half of the invention has already been installed on the other side of the net, and a second half of the invention partially assembled on the viewer's side of the net.

FIG. 3 b shows a close-up view of one section, as it is installed at the net.

DESCRIPTION

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.
FIG. 1 shows the complete view of the Smart Net 11. The nine sections in full view, which service one side of the tennis net, are clipped together to form a continuous structure that spans the full length of a standard tennis net 20. Another nine sections span the net, along its other side.
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.
FIG. 1 also shows that the exposed surface of the Smart Net tapers away from the net, as one views it from the center, toward either end of the net. The Smart Net tapers out from the center of the net, so that every section substantially faces toward the center of the baseline. This causes the ball to tend to angle toward the middle of the baseline as it rolls off, regardless of where along the net the ball drops. Note that, even if a flying ball strikes the net at an angle, the ball will effectively come to a stop in the net, and tend to drop straight down. The degree of taper that is manufactured into the invention can be greater than what is shown in the diagram, as much as desired.
FIG. 1 a shows one section 5 of the Smart Net. The sections are designed to be stackable. Each section has a firm curved surface 51, which converts the movement of a falling tennis ball into a rolling energy (angular momentum). The section also has a specially-shaped notch 52 cut out of each end. These notches make room for the connecting clips that allow the invention to be assembled.
FIG. 1 b shows a connecting clip 10. This part is used to join one section to the next. The connecting clip also joins the two halves of the complete invention together, keeping both sides secured to the tennis net. (FIG. 3 b shows this in greater detail.)
FIG. 2 shows a set of nine sections in a double-stacked arrangement that comprises one-half of a full Smart Net. The sections are so shaped that they will nest neatly together to form the double-stack 12.
FIG. 2 b shows a double-stack 12 near the base of the net 20 at one end. An assembled half of the Smart Net 11 is also shown on the opposite side.
FIG. 3 shows a partial Smart Net under assembly on the viewer's side of the net 20, as sections are taken from its double-stack 12. A completed half of the Smart Net 11 is shown on the opposite side of the net.
FIG. 3 b shows a close-up view of the end of one of the sections. The connecting clip 10 fits two sections together, on each side of the net 20. (The netting mesh of the net is not shown in the figure.) Each new section is simply clipped to the precious one, to complete the assembly. The connecting clip runs underneath the net, and straddles the assembled invention on either side of the net. So, each connecting clip will secure four sections together, in the completed assembly of the Smart Net.

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.