Abstract:
A training baseball bat has an internal movable magnet that accelerates to the end of the bat when swung at a fast enough speed. As the magnet moves it passes through a coil that is connected to one or more LEDs so that the LEDs momentarily flash as the magnet moves through the coil. An axially positionable stationary magnet can be used to hold the movable magnet until sufficient centrifugal force is imparted by the swing to overcome the magnetic holding force.

Description:
[0001]    This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 12/053,824, filed Mar. 24, 2008, which in turn claims priority to U.S. provisional patent application 60/942,055, filed Jun. 5, 2007, incorporated herein by reference. 
     
    
     I. FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to baseball bats used for training purposes. 
       II. BACKGROUND OF THE INVENTION 
       [0003]    A properly executed baseball swing is a difficult skill to learn, because while swing mechanics can be told to a batter, the muscle coordination necessary to execute a superior swing is dauntingly complex. First, to impart optimum power the bat should be swung in an optimum swing plane that is substantially horizontal, i.e., it ideally exhibits a slight uppercut a few degrees from horizontal, although depending on ball location, other swing planes may be used. 
         [0004]    But not only must the bat swing follow a preferred swing plane, the speed of the bat head should be at an acceptably high magnitude at a particular point in the plane, namely, the point at which contact with the ball is made. While exceptions may be made by skilled batters depending on special circumstances, e.g., in an effort to hit to the opposite field, the generally accepted optimal contact point is just in front of the batter toward the pitcher, typically where the swing plane intersects a vertical line extending from just in front of home plate. 
         [0005]    The muscular coordination is further complicated by the fact that the head and shoulders must cooperate with the torso and hips to accelerate the bat through the contact point while maintaining the focus of the eyes on the ball at the point of contact. Allowing the shoulders to open prematurely, i.e., allowing the lead shoulder to swing toward the foul line too early in the swing, results in less power and missed pitches as the head and eyes are jerked from where focus should be, while leaving the shoulders closed too long results in less power in the swing. 
       SUMMARY OF THE INVENTION 
       [0006]    A baseball training bat has a handle and a barrel formed with a channel from the end of the barrel, extending toward the handle. A first magnet in the channel rides axially on a lead screw within the handle to a user-desired location. A movable magnet is also disposed in the channel for translational movement between a housed position, wherein the movable magnet is adjacent the first magnet and wherein magnetic attraction holds the movable magnet in the housed position, and a swung position, toward which the movable magnet moves when sufficient centrifugal force is imparted to the movable magnet to overcome the magnetic attraction between the magnets. 
         [0007]    In example embodiments a wire coil can surround at least a portion of the channel. The movable magnet moves through the coil when the movable magnet moves from the housed position to the swung position to induce a temporary electrical signal in the coil. A light emitting diode (LED) is mounted on the barrel and is visible to a person swinging the bat. The LED is electrically connected to the coil to emit a flash of light at least in response to the movable magnet moving rapidly through the coil as a batter swings the bat. The bat need not contain a source of electrical power apart from the electrical power generated by the movable magnet moving through the coil. 
         [0008]    The bat can be made of wood or metal or composite materials. Plural LEDs can be provided on the barrel. If desired, a non-magnetic spacer can be disposed between the magnets and can define a thickness in the dimension of the long axis of the bat. The thickness is established such that centrifugal force overcomes magnetic attraction between the magnets to move the movable magnet when the bat is swung at least as fast as a desired bat speed. A tube in the channel can hold at least the movable magnet, and the spacer may be disposed in the tube. A cap can be engaged with the end of the barrel. The cap may hold a shock absorbing pad contacted by the movable magnet when the movable magnet reaches the swung position to generate audible and tactile feedback signals thereof to a person swinging the bat. 
         [0009]    In another aspect, a baseball training device includes a handle connected to a barrel. The barrel has an end distanced from the handle, and a channel is formed in the barrel from the end of the barrel and extending toward the handle. A movable magnet is disposed in the channel. A first magnet assembly includes a first magnet for urging the movable magnet toward a housed position, wherein the movable magnet can move between the housed position and a swung position when sufficient force is imparted to the movable magnet to overcome the first magnet. An adjustment assembly is threadably engaged with the first magnet assembly and is rotatable by a person to establish an axial location of the first magnet to vary as desired the force needed to separate the magnets. 
         [0010]    The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of the training bat as it would be swung from the right side of a home plate, at the desired location of ball contact in front of a right-handed batter; 
           [0012]      FIG. 2  is a cross-sectional view as would be seen along the line  2 - 2  in  FIG. 1 , with the moving magnet in the housed position, with portions of the bat body broken away for clarity; 
           [0013]      FIG. 3  is a cross-sectional view as seen along the line  2 - 2  in  FIG. 1 , with the moving magnet moved by an adequate centrifugal force from the housed position to the swung position, causing it to move through the coil to produce a temporary Faraday electromotive voltage therein to temporarily illuminate the visual indicators, with portions of the bat body broken away for clarity; 
           [0014]      FIG. 4  is an exploded perspective view of the internal components of an embodiment of the bat; 
           [0015]      FIG. 5  is a partially cut away side view of an alternate embodiment that in all substantial respects is identical to that shown in  FIGS. 1-4 , except that the stationary magnet can be located axially within the bat as desired by the user; 
           [0016]      FIG. 6  is a perspective view of an example magnet assembly guide for the embodiment shown in  FIG. 5 ; 
           [0017]      FIG. 7  is a perspective view of an example magnet assembly for the embodiment shown in  FIG. 5 , with the magnet removed and portions shown in phantom for clarity; 
           [0018]      FIG. 8  is a perspective view of an example magnet assembly for the embodiment shown in  FIG. 5 , with portions shown in phantom for clarity; 
           [0019]      FIG. 9  is a perspective view of the distal portion of the lead screw assembly for the embodiment shown in  FIG. 5 , with portions broken away; and 
           [0020]      FIG. 10  is a perspective view of the proximal portion of the lead screw assembly for the embodiment shown in  FIG. 5 , with portions broken away. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    Referring initially to  FIG. 1 , a training bat is shown, generally designated  10 , which includes a handle  12  connected to a barrel  14 . The bat  10  may be made of wood or metal or composite materials and may be a conventional bat altered in accordance with present principles. 
         [0022]    As shown in  FIG. 1 , visible indication can be provided on the barrel  14  of the barrel  14  being swung in a preferred swing plane described by the arc  16  at or greater than an acceptable speed as it passes through an imaginary vertical line  18  intersecting a preferred location in the arc, typically just in front of a home plate  20  next to which a batter in training typically would stand ( FIG. 1  assumes a right-handed swing). The visible indication, however, is not provided if the barrel  14  passes through the imaginary vertical line  18  at less than the acceptable speed. 
         [0023]    In the embodiment shown in  FIG. 1 , the visible indication is a flash of light generated by a source of light such as one or more lamps. In the non-limiting embodiment shown, plural light emitting diodes (LED)  22  are mounted on the surface of the barrel  14  for operation to be shortly disclosed. 
         [0024]      FIGS. 2-4  show non-limiting details of one preferred implementation of the bat  10 . Cross-referencing  FIGS. 2-4 , a channel  24  extends into the barrel  14  from the end  26  of the barrel  14 . Preferably, the channel is located coaxially with the long axis of the bat  10 . A cap  28  covers the open end of the barrel as shown. 
         [0025]    At the closed end of the channel, a disk-shaped stationary magnet  30  is located. If desired, a first disk-shaped spacer  32  may be positioned in the channel to abut the stationary magnet  30 . In the non-limiting implementation shown, a hollow, typically plastic tube  34  with a closed end is then advanced into the channel closed end first. To fixedly hold these components within the channel  24 , epoxy  36  may be deposited in the channel  24  as shown. 
         [0026]    At least one second spacer  38  having a thickness “t” ( FIG. 4 ) is positioned within the tube  34  against its closed end. As perhaps best shown in  FIG. 4 , the spacer  38  may be centrally formed with a hub  40 , and the hub  40  protrudes toward and may be receivable in an interference fit with a channel  42  of an otherwise disk-shaped movable magnet  44 . The pole of the movable magnet  44  facing the stationary magnet  30  is the opposite polarity of the pole of the stationary magnet  30  that faces the movable magnet  44 , so that the magnets attract. The magnets may be, without limitation, neodymium magnets or iron magnets. 
         [0027]    It may now be appreciated that the magnetic attraction between the magnets  30 ,  44  (aided if desired by the frictional fit between the hub  40  and channel  42  of the movable magnet  44 ) holds the movable magnet in the housed position shown in  FIG. 2 . It may be further appreciated that when sufficient centrifugal force is imposed on the movable magnet  44  toward the end of the bat, i.e., when the bat is swung at sufficient speed, the magnetic attraction is overcome and the movable magnet  44  rapidly slides down the tube  34  toward the end of the bat to the swung position shown in  FIG. 3 . It may be still further appreciated that the separation force needed to move the movable magnet  44  to the swung position depends on the strength of the magnetic attraction in the housed position and, hence, on the thickness “t” of the spacer  38 . The thickness “t” thus may be established to establish the bat speed at which the magnet  44  moves to the end of the bat. To this end, several spacers  38  of varying thickness may be provided, and the user can select thicker spacers (and hence lower separation bat speeds) for younger batters and thinner spacers (and hence higher separation bat speeds) for older batters. Or, multiple spacers of the same thickness may be provided, and the user simply inserts as many spacers as are required to achieve the desired separation bat speed. Insertion of the desired spacer or spacers  38  is easily done by removing the cap  28  from the barrel to expose the open end of the tube, removing the movable magnet, inserting into the tube (and/or removing from the tube) spacers  38  as desired, inserting the movable magnet back into the tube, and re-engaging the cap with the barrel. 
         [0028]    A wire coil  46  surrounds the tube  34  and is electrically connected to the LEDs  22 , which advantageously are mounted in a depression  48  in the surface of the barrel  14  and surrounded by a transparent material such as transparent epoxy. Accordingly, when the magnet  44  passes through the coil  46 , an electrical signal is temporarily induced in the coil  46 , temporarily energizing the LEDs  22  to cause them to appear to flash briefly. Since no energy need be stored in, e.g., a battery, the bat  10  need contain no source of electrical power apart from the electrical power generated by the movable magnet  44  moving through the coil  46 . 
         [0029]    Completing the description of  FIGS. 2-4 , the cap  28  holds a shock absorbing pad  50  that is contacted by the movable magnet  44  when the movable magnet  44  reaches the swung position shown in  FIG. 3  to generate audible and tactile feedback signals to a person swinging the bat. As shown, the cap  28  can have male threads  52  that engage a complementarily threaded passage in the barrel  14 , or the end of the barrel  14  may be externally threaded to engage an internal female thread structure of an alternate cap  28 . Other means including set screws may be provided to hold the cap  28  onto the end of the bat. 
         [0030]    With the non-limiting example embodiment described above, development of a short, powerful swing by a batter is facilitated. Specifically, embodiments of the invention help develop muscular coordination for the short swing by only giving positive feedback if the swing has produced the centripetal acceleration necessary to produce the centrifugal force required to release the magnet through the coil. Once bat speed is maximized, momentum carries the bat at that speed through the remainder of the swing. In addition to producing maximum bat speed, the short swing also requires substantially less time to move the bat from the ready position to the hitting zone, giving more time to react to pitch location, and requires less movement to orient the swing plane to the pitch location. 
         [0031]    Practicing with the present bat helps train the batter to generate the maximum bat speed of which that batter is capable, and to do so with optimum plate coverage, bat orientation, swing plane, and body position. If any of those factors are absent, the LEDs will not flash in the proper location, or will not flash at all. 
         [0032]      FIGS. 5-10  illustrate an alternate bat  100  which is in all essential respects identical to the bat described above, except that the stationary magnet may be positioned as desired along the barrel of the bat to establish a desired separation force by means of rotating a lead screw assembly. With more particularity, a coil  102  can be disposed in the barrel of the bat as shown in accordance with disclosure above to receive a movable magnet therethrough when a person swings the bat and, when the swing is sufficient, to illuminate LEDs  106 . 
         [0033]    To hold the movable magnet in the above described housed position, a magnet  108  that is stationary during swinging is disposed in the bat. Unlike the above-described stationary magnet however, the magnet  108  can be part of a magnet assembly that rides axially within a guide  110  on a user-rotatable lead screw assembly  112 . The user can rotate the lead screw assembly to move the magnet  108  toward and away from the end of the bat as desired to establish a stronger or weaker swing force that will be necessary to separate the magnets. 
         [0034]      FIG. 6  shows that an example guide  110  can have a unitary hollow cylindrical body  114  formed with one or more axially-oriented rectilinear channels  116 . In the example shown, three channels  116  are provided and are spaced equidistantly around the circumference of the body  114 . The axial length of the body  114  may be, e.g., one and one half times the intended axial throw distance for the magnet  108 . The guide  110  may be glued within or otherwise affixed to the barrel of the bat. 
         [0035]      FIGS. 7 and 8  show an example magnet assembly  118  which is fixedly attached to the magnet  108  ( FIG. 8 ). The magnet assembly  118  may include a hollow cylindrical body  120  sized to fit within the cylindrical body  114  of the guide  110 . The body  120  includes one or more radially-protruding, axially elongated rectilinear ribs  122 , it being understood that the number and spacing of the ribs  122  on the magnet assembly  118  matches the number and spacing of the channels  116  on the guide  110 . Accordingly, it may now be appreciated that the magnet assembly  118  can slide axially within the guide  110  but owing to the cooperation of the ribs  122  with the channels  116 , cannot rotate within the guide  110 . 
         [0036]    The magnet assembly body  118  is interiorly formed with a lead screw groove  124 . Also, to hold the magnet  108  as part of the assembly  118 , threads  126  may be formed in an end of the assembly body  120  as shown for receiving a threaded fastener  128  ( FIG. 8 ) to trap the magnet  108  between the enlarged head  130  of the fastener  128  and the assembly body  120 . Other means of affixed the magnet  108  to the body  120  such as adhesives or welding or soldering may be used. 
         [0037]    The lead screw assembly  112  and its structure for engaging the magnet assembly  118  can be appreciated in reference to  FIGS. 9 and 10 . The distal end portion  132  of the lead screw assembly  112  may be radially sized to closely fit within the hollow body  120  of the magnet assembly  118 . The distal portion  132  is exteriorly formed with a throw thread  134  ( FIG. 9 ) which threadably engages the lead screw groove  124  of the magnet assembly  118 . In contrast, the distal end  136  ( FIG. 10 ) of the lead screw assembly is juxtaposed with the handle of the bat and can be rotated by a person. It may now be appreciated that as a person rotates the lead screw assembly  112 , the magnet assembly  118  with magnet  108  rides axially in the barrel of the bat to whatever location in its throw distance the user desires. 
         [0038]    In the embodiment shown in  FIG. 10 , a nut  138  can be implanted in an end knob  140  of the bat  100 . The distal end  136  of the lead screw assembly  112  may be threaded as shown to engage the nut  138 . A bushing or nut  142  may surround the distal end  136  on the surface of the knob  140  as shown. The knob  140  can be turned to rotate the lead screw assembly  112  within the handle  144  of the bat  100  to move the magnet  108  as described above. 
         [0039]    While the particular TRAINING BAT WITH VISUAL FEEDBACK OF PROPER SWING is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.