Patent Application
20180333613
This invention relates generally to baseball and more particularly to youth sized baseballs.
Baseball is known as America's pastime. It is played on a field with a bat, a ball, and nine players on each team. Professional baseball has established regulations for the size and weight of bats that can be used, the size and weight of the ball that can be used, and the dimensions of the field. For instance, the baseball is spec' d to have a circumference in the range of 9.0 to 9.25 inches and to have a weight in the range of 5.0 to 5.25 ounces. Professional baseball has also established a coefficient of restitution (COR) for baseballs of 0.5.
Youth baseball has similarly established regulations for the size and weight of bats and for the dimensions of the field. Youth baseball, however, has no regulations for the size and weight of baseballs. As such, youth baseball uses baseballs that conform to the professional regulations.
A proper grip of the baseball promotes proper throwing mechanics. At the point of release, for example, this grip allows the wrist to snap through the throw such that the fingers are pulling down on the baseball, creating a back-spin. With the thumb centered between the fingers, the wrist maintains a perpendicular alignment with the target of the throw and minimizes unintentional rotation of the hand and forearm. Forearm rotation during a throw tends to put more stress on the elbow and/or the shoulder, making them more susceptible to injury.
The weight of the “Butcher Ball” may also be reduced by 60%-90% of the weight of the professionally spec'd baseball, which is 5.0 to 5.25 ounces. For example, the “Butcher Ball” weighs between 3.0 and 4.7 ounces. In an embodiment, the “Butcher Ball” weighs 4.1 ounces.
With the size of the ball reduced, a youth player can achieve the proper grip 18. The proper grip enables proper throwing mechanics. There are several studies that indicate that proper throwing mechanics are important in reducing the risk of an arm injury. In particular, in reducing elbow injuries and shoulder injuries.
The finger and thumb grip alignment areas 20-24 are positioned on the ball to assist the player with obtaining a proper grip of the baseball. Each grip alignment area (finger and thumb) provides a tactile feel that is different from the tactile feel of the rest of the ball and may be implemented in a variety of ways. For example, the grip alignment areas 20-24 are fabricated in the synthetic outer material. As another example, the grip alignment areas are stick-on sheets that have a tactile feel such as a knurl, rippled surface, dimpled surface, etc. As yet another example, the grip alignment areas are stitched into the surface of the ball and one or more areas may coincide with conventional stitching of a baseball.
From the overhead view of
Generally, the energy attributable to recoil of a solid wood bat is much less than the energy attributable to the compression/decompression of the baseball and, as such, we will ignore it for this discussion. The recoil of a hollow bat (e.g., a corked bat or some aluminum bats), however, may be significantly more than a solid wood bat and release non-negligible energy into the baseball, which adds to the baseball's exit velocity.
Turning to the transfer of momentum from the bat to the baseball. Mathematically, momentum is defined as the mass of object (in kilograms) times its velocity (in meters per second).
Momentum (P)=mass (m)*velocity (V)
From a practical standpoint, an object that is moving has momentum. The faster the object is moving and the more it weighs, the more momentum it has. For example, a car that weighs 4000 pounds (e.g., 1818.2 kg) traveling at 10 mph (e.g., 4.47 meters per second (m/s)), has more momentum than a baseball that weighs 4 ounces (0.113 kg) traveling at 200 mph (89.4 m/s). In this example, the car has a momentum of 8,127 kg*m/s and the baseball has a momentum of 10.1 kg*m/s. It is not hard to image that, if the car and baseball were traveling at each other and collided, the baseball would get the worse of that collision.
A few more equations regarding the laws of physics are needed to explain the transfer of momentum. They are:
Force (F) =mass (m) * acceleration (a)
acceleration(a)=change in velocity (ΔV)/change in time (Δt)
Kinetic Energy (KE) =0.5*mass (m)*acceleration squared (a2)
Fs=−Fb
Momentum of Swing before Contact (Psb)+Momentum of Baseball before Contact (Pbb)=Momentum of Swing after Contact (Psa)+Momentum of Baseball after Contact (Pba)
Psb+Pbb=Psa+Pba, or
ms*Vsb+mb*Vbb=ms*Vsa+mb*Vba
KEsb+KEbb=KEsa+KEba+Ball compression/decompression
ΔP=ms*Vsa−ms*Vsb =mb*Vba−mb*Vbb
Before applying these equations to the exit velocity of the baseball that results from the bat-baseball collision, an explanation of each of the equations provides insight into exit velocity. Starting with acceleration and in practical terms, acceleration means how fast velocity (speed in a given direction) of an object is increasing or decreasing (a positive value for increasing and a negative value for decreasing). For example, a car changing its speed from 0 to 30 mph is accelerating and a car changing its speed for 30 mph to 0 is decelerating (i.e., has a negative acceleration). The value of acceleration is how fast the car changes its speed in a time period. If car goes from 0 to 30 mph in 1 second, then the car is accelerating at a rate of 30 mph per second; if it done in 2 seconds, then the car is accelerating at a rate of 15 mph per second (i.e., 30/2); and if it is done in a half a second, then the car is accelerating at a rate of 60 mph per second (i.e., 30/0.5). If the car is traveling at a constant speed, then it is not accelerating and, as such, has zero acceleration.
Force is the effort required to change the momentum of an object from a first momentum to a second momentum. If an object is stationary (i.e., has zero momentum), then a force is required to get the object moving from 0 to a given velocity within a given time frame (e.g., a second). For example, the force required for a 4,000 pound car to go from 0 mph to 2 mph in one second is 8,000 force pounds. The same applies if the first momentum is not zero. For example, the same force is needed to change the velocity of the car from 2 mph to 4 mph in one second as is needed to change the velocity of the car from 0 to 2 mph in one second.
Kinetic energy is the energy an object as a result of its acceleration from its first momentum to its second momentum. If an object is stationary (i.e., has zero momentum) and is accelerated from 0 to a given velocity, it has a kinetic energy of 0.5 times its mass time its acceleration squared. For example, a 4,000 pound car that is accelerated from 0 mph to 3 mph in one second has a kinetic energy of 18,000 (lbs (mph/sec)2) [0.5*4000*32].
Newton's third law means that when two objects collide they apply an equal and opposite force on each other during the collision. In the bat-baseball collision, the bat provides a force on the baseball that is equal to and in the opposite direction to the force applied by the baseball on the bat. In mathematical terms,
Fs=−Fb
where Fs represents the force of the swing (i.e., the force applied by the bat) and Fb represents the force of the baseball. Since force=mass times acceleration, Newton's third law equation can be rewritten as:
ms*as=−mb*ab
where “ms” represents the mass of the swing, “as” represents the acceleration of the swing, “mb” represents the mass of the baseball, and “ab” represents the acceleration of the baseball. Since acceleration equals a change in velocity divided by the time in which the change occurs (a=ΔV/Δt; where ΔV=Va−Vb and Δt=ta−tb, where “a” corresponds to just after the collision and “b” corresponds to just before the collision), Newton's third law equation can be rewritten as:
ms*(Vsa−Vsb)/t=−mb*(Vba−Vbb)/t
where Vsa is the velocity of the swing after contact, Vsb is the velocity of the swing before contact, Vba is the velocity of the baseball after contact, and Vbb is the velocity of the baseball before contact.
Since the time of the collision is the same for both the swing and the baseball, the above equation can be rewritten as:
ms*(Vsa−Vsb)=−mb*(Vba−Vbb)
which is the equation for conservation of momentum for the bat-baseball collision.
The conservation of momentum equation can be written in terms of momentum of the swing and the baseball before the collision and of the momentum of the swing and baseball after the collision. Mathematically,
ms*Vsa−ms*Vsb=−(mb*Vba−mb*Vbb)
mb*Vbb+ms*Vsb=mb*Vba+ms*Vsa
The change in momentum for the bat in the bat-baseball collision is:
ms*Vsa−ms*Vsb
mb*Vba−mb*Vbb.
The last equation to discuss is the conservation of energy. What this equation is expressing is that, the energy before the collision equals the energy after the collision. Meaning, that no energy is lost during the bat-baseball collision, although some of the energy is converted from one type of energy to another. For example, some of the kinetic energy of the baseball and of the swing prior to collision is transformed into heat and into compression and decompression the baseball during and after the collision. The remaining portions of the before collision kinetic energy of the baseball and the swing are transferred into the swing of the bat and in the baseball after the collision.
Ignoring the heat that results for the collision, the vibration of the bat, and the recoil of the bat, since they should be relatively small in comparison to the other factors, exit velocity of the baseball is based on the mass of the baseball (mb), the before-contact velocity of the baseball (Vbb), the compression/decompression of the baseball, the mass of the swing (ms), the before-contact velocity of swing (Vsb), the after-contact velocity of the swing (Vsa), and the time of the contact.
The mass of the baseball (mb) is between 3.0 and 4.7 ounces. The velocity of the baseball before contact (Vbb) is the pitch speed, which varies from pitch to pitch, but for a given pitch, it can readily be determined. The other factors (the mass of the swing (ms), the before-contact velocity of swing (Vsb), the compression/decompression of the baseball, and the after contact velocity of the swing (Vsa)) are a little harder to determine.
To begin, the velocity of a swing starts at 0. The hitter exerts a force to accelerate the bat and his/her body from 0 to the before contact velocity in about 140 mSec (about 1/7th of a second). After contact, the hitter exerts a force to decelerate the bat and his/her body from the after-contact velocity to 0. Most youth hitters can produce a swing velocity of 50-70 mph (miles per hour).
The most difficult term to determine is the mass of the swing (ms), which is a combination of the mass of the bat, the mass of the hitter, and the strength of the hitter's body and bat alignment at the point of contact. As shown in
Another factor that effects exit velocity is the hitting alignment of the bat and ball. Perfect alignment is shown in
The coefficient of restitution (COR) is a primary factor in determining the losses attributable to the compression/decompression of the baseball. COR is a measure of the “bounce back” of an object when it bounces off of a wall or solid ground. A COR of 1 has a 100% bounce back effect (e.g., drop a ball from a height of three feet onto a rigid flat surface, the ball will bounce back up to three feet, ignoring air resistance). A COR of 0 has a 0% bounce back effect (e.g., regardless of the height, the ball will not bounce (e.g., a stone has a near zero COR and does not bounce when it contacts a solid surface). A COR of 0.5 has a 25% bound back effect ((e.g., drop a ball from a height of four feet onto a rigid flat surface, the ball will bounce back up to one foot). Professional baseballs have a coefficient of restitution (COR) of 0.5.
To illustrate the COR effect on a baseball's exit velocity, assume that the bat functions as a rigid surface (e.g., like a swinging brick wall that does not vibrate, recoil, or changes its velocity) during the collision. With a COR of 0.5, a baseball would have an exit velocity of the swing velocity+0.25 times the pitch velocity. Of course, the bat does vibrate, it does recoil, and it does change its velocity, so the effect of compression/decompression of baseball on its exit velocity is less than 0.25 times the pitch velocity. If the bat has too much vibration or change in velocity, the contribution to the ball's exit velocity from its compression/decompression could be zero. As such, the exit velocity of a baseball is a function of the swing velocity, the pitch velocity, and the COR of the baseball, with a maximum exit velocity of the swing velocity plus 0.25 times the pitch velocity.
In youth baseball, there is often a substantial range is size, weight, and strengthen of the players. For instance, it is not uncommon for a team to have one player that is under 5 feet tall and weighs less than 100 pounds and have another player that is 6 feet or taller and weighs 200 pounds or more. As such, there is a wide range of effective mass of the swing in youth baseball. A physically advanced youth player can generate exit velocities over 90 mph. At 90 mph, the ball travels 161 feet in 1.22 seconds. With reduced size of the field and varying skill levels of the players, a 90 mph exit velocity is dangerous if the ball is hit at the pitcher or one of the corner infielders. Further, with a launch angle of 30 degrees and a 90 mph exit velocity, the ball will carry over 350 feet, which is far longer than needed to hit a home run on youth fields (e.g., fences are about 225 feet from home plate).
In an embodiment of a youth baseball, the ball includes a construction that limits the momentum of the baseball once the momentum of the bat (i.e., the effective mass of the swing) reaches a certain level. With reference to
To limit the exit velocity to a particular velocity, the coefficient of restitution (COR) of a youth sized baseball is varied as shown in
The first inner material 42 has a first compression level and a first coefficient of restitution (COR) and the second inner material 44 has a second compression level and a second COR. Each of the first and second inner materials 42 & 44 is of a different composition of plastic, polyurethane (PU), polyethylene (PE), ethylene-vinyl acetate (EVA), EVA rubber, rubber, cork, silicone gel, foam, and/or a composition thereof. The first compression level is stiffer than the second compression level and the first COR is greater than the second COR.
In effect, when the Butcher Ball is not hit overly hard (e.g., less than the maximum exit velocity of
For instance, the first inner material 42 has properties similar to a conventional baseball when it is compressed less than a first compression level as shown in
When the Butcher Ball is hit hard (e.g., at or above the maximum exit velocity if it were a conventional baseball), the combination of the first and second materials 42 & 44 limits the exit velocity to the maximum exit velocity. For instance, the second inner material 44 has properties that reduce the overall COR of the ball when it is compressed more than the first compression level as shown in
It is noted that terminologies as may be used herein such as bit stream, stream, signal sequence, etc. (or their equivalents) have been used interchangeably to describe digital information whose content corresponds to any of a number of desired types (e.g., data, video, speech, audio, etc. any of which may generally be referred to as ‘data’).
As may be used herein, the terms “substantially” and “approximately” provides an industry-accepted tolerance for its corresponding term and/or relativity between items. Such an industry-accepted tolerance ranges from less than one percent to fifty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. Such relativity between items ranges from a difference of a few percent to magnitude differences.
As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1. As may be used herein, the term “compares unfavorably”, indicates that a comparison between two or more items, signals, etc., fails to provide the desired relationship.
One or more embodiments have been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claims. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality.
To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claims. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof.
In addition, a flow diagram may include a “start” and/or “continue” indication. The “start” and “continue” indications reflect that the steps presented can optionally be incorporated in or otherwise used in conjunction with other routines. In this context, “start” indicates the beginning of the first step presented and may be preceded by other activities not specifically shown. Further, the “continue” indication reflects that the steps presented may be performed multiple times and/or may be succeeded by other activities not specifically shown. Further, while a flow diagram indicates a particular ordering of steps, other orderings are likewise possible provided that the principles of causality are maintained.
The one or more embodiments are used herein to illustrate one or more aspects, one or more features, one or more concepts, and/or one or more examples. A physical embodiment of an apparatus, an article of manufacture, a machine, and/or of a process may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the embodiments discussed herein. Further, from figure to figure, the embodiments may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones.
While particular combinations of various functions and features of the one or more embodiments have been expressly described herein, other combinations of these features and functions are likewise possible. The present disclosure is not limited by the particular examples disclosed herein and expressly incorporates these other combinations.
The present U.S. Utility Patent Application claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/507,002, entitled “Youth Baseball”, filed May 16, 2017, which is hereby incorporated herein by reference in its entirety and made part of the present U.S. Utility Patent Application for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 62507002 | May 2017 | US |
