US 20030144089 A1
A baseball practice bat has a movable handle portion disposed around a shaft between the barrel portion of the bat and the knob at the other end of the bat to provide sensual, visual, audible or electronic feedback to a practice hitter or coach as to proper hand and arm position while hitting a ball based on temporal feedback from the motion of the movable handle.
1. A baseball practice bat, comprising:
a) a shaft having a first end and a second end,
b) a knob disposed at the first end of said shaft,
c) a barrel disposed at the second end of said shaft,
d) a movable handle located around said shaft between said barrel and said knob,
e) said movable handle configured to translate along said shaft to provide indication of a correct baseball swing,
f) wherein the motion of the movable handle toward the knob is sensed during the execution of a swing.
2. The baseball practice bat of
3. The baseball practice bat of
4. The baseball practice bat of
5. The baseball practice bat of
6. The baseball practice bat of
7. The baseball practice bat of
8. The baseball practice bat of
9. The baseball practice bat of
10. The baseball practice bat of
11. The baseball practice bat of
12. A kit for adapting a baseball bat to a practice bat, the kit comprising:
a) a movable handle assembly.
13. The kit of
14. The kit of
15. The kit of
16. The kit of
17. The kit of
 This application is a continuation-in-part of U.S. Utility patent application Ser. No. 10/175,513 filed Jun. 19, 2002, and published on Jan. 16, 2003 as US-2003-0013563-A1, which is a continuation-in-part of U.S. Utility patent application Ser. No. 09/735,725 filed Dec. 12, 2000, now issued U.S. Pat. No. 6,406,387, which is incorporated by reference in its entirety.
 The present invention relates generally to the field of baseball equipment. More particularly, the invention relates to a practice bat for baseball.
 The game of baseball has been played in the United States for more than one hundred years. The game is played by opposing teams and consists primarily of a pitcher of one team throwing a ball to a batter of the other team who attempts to hit the ball with the bat and to run to each of four bases without being tagged out.
 The bat is round in cross section and narrow in diameter, thereby making it difficult to hit a ball, which tends to be only slightly larger in diameter than the bat barrel. Bats are generally constructed of wood or aluminum. There tend to be no moving parts on a baseball bat. Baseball players tend to spend many hours practicing their hitting technique so that when they play the game, they can hit the ball with maximum efficiency.
 Hitting coaches know that the most efficient way to swing a bat for optimal performance is to have the leading arm do most of the work until the ball makes contact with the barrel of the bat. After that, both hands and arms are used equally. It is difficult, with a standard bat, for the batter or the coach to verify that the batter is actually using his or her leading arm properly. Additionally, coaches train their players to hold the bat in such a way that the batters knuckles of one hand are aligned with the knuckles of the other hand. This ideal alignment is also difficult to verify during the swinging process.
 The present invention is implemented in the form of a baseball practice bat having a main bat barrel disposed at one end of a shaft, a knob disposed at the opposing end of the shaft and a movable handle portion that translates along the shaft between the barrel section and the knob. Accordingly the user, a practice batter, grips the shaft just above the knob with their leading hand (i.e. left hand for “right handed” hitting) and then uses the trailing hand to both grip the moving handle and displace it away from the leading handing. Thus, when upon properly swinging the bat the trailing hand will urge the movable handle towards the knob at the moment of impact with the ball.
 Various embodiments provide other features, devices and methods for sensing and correlating the balls impact with the bat with the translation of the movable handle on the shaft and the positions the moving handle using the trailing hand gripping the movable handle
 In additional embodiments a second handle grip is provided above the knob so as to provide feedback on the correct rotation of the leading and trailing hand during the swing by reference to the rotational position of the movable and fixed handle at the moment of impact with the ball.
 In further embodiments various methods are deployed to provide the practice batter or coach with visual, audible, sensory or electronic feedback that correlate the position and/or rotation of the movable grip at the moment of impact with the baseball.
 In yet additional embodiments the aforementioned features, devices and methods for sensing and correlating the balls impact with the bat with the movable grip position are provided in the form of a kit adapted to be added as well as removed from a regulation baseball bat; such as one might use in play.
 Other objects and advantages of the invention will no doubt occur to those skilled in the art upon reading and understanding the following detailed description along with the accompanying drawings.
 The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings.
FIG. 1 is a cross-sectional view of the baseball practice bat.
FIG. 2 is a perspective view of a person starting a swing using the practice bat.
FIG. 3 is a perspective view of a person during a swing using the practice bat.
FIG. 4 is a cross-sectional view of a second embodiment of the practice bat.
FIG. 5 is a cross-sectional view of another embodiment of the practice bat.
FIG. 6 is a partial cut-away view of another embodiment of the practice bat.
FIG. 7A, 7B and 7C are elevations of further embodiments of the practice bat.
FIG. 8A is a perspective view of a movable handle and optional stop or fixed handle or grip for retrofitting to an existing bat. FIG. 8B is an elevation sectional view of one embodiment of the movable handle. FIG. 8C is a perspective view of the movable handle of FIG. 8B prior to application. FIG. 8D is a cross section through the perspective view in FIG. 8C. FIG. FIG. 8E is a cross-sectional view of one embodiment of the optional stop for retrofitting to an existing bat.
FIG. 9 is a cross-sectional view of another embodiment of the practice bat having incorporating one or more electronic sensor to enable alternative feedback and data logging schemes.
 Detailed descriptions of the preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
FIG. 1 is a side, sectional view of the baseball practice bat of the present invention. Although the following description will refer to the term baseball bat in describing the present invention, it should be understood that the present invention also includes softball bats. The bat 100 is comprised of three main functional elements, the main bat barrel 130, the movable handle 120 and the knob 110, all connected by a centrally located generally rigid shaft 160. These functional elements are preferably expressed in a substantially monolithic construction, for example as in a traditional baseball bat formed by turning a single piece of wood in a lathe. The shaft 160 may be made from a tubular material such as stainless steel or may be made of solid material such as fiberglass, aluminum or wood. Movable handle translates along the region of shaft region 160 defined by the bottom of barrel 130 and the batter's leading hand placed above knob 110. While movable handle 120 is illustrated as having indentations or ridges molded in the contour of finger this is optional, for example when it is desirable to correlate the rotation of handle 120 about shaft 160 during the practice swing. that form finger grips, this is optional
 The practice bat of the present invention is used in the following way, as shown in FIG. 2 and FIG. 3. The user 50 grips the bat shaft or the illustrated fixed handle 100 attached above the knob 110 with the leading hand using the trailing hand to grip and slide the movable handle 200 up close to bat barrel 300. The leading arm and hand 52 is held in the normal fashion. One key to optimal hitting is to let the leading hand and arm 52 do most of the work until the ball 62 strikes the bat barrel 300, after which point both the leading arm 52 and the trailing arm 54 share the work equally. If the batter is using his leading arm 52 correctly the sliding handle 200 will not slide down rigid shaft 160 and meet the fixed handle 100 prior to the batter hitting the ball.
 Additionally, the rotation of movable handle 200 about the axis of the bat barrel and shaft provides further indicia of a poor or inferior swing. In a proper swing the batter's hands remain in substantially the same orientation to each other with respect to the plane of the hands, as if the palm was fully opened rather than gripping the bat. The handles remaining parallel to each other during the swing is usually manifested by retaining the alignment of the knuckles of each hand at the completion of the swing, which can be indicated by various means as described in further embodiments. However, as the free rotation of the movable grip about the shaft also causes the player to tend to not strike the ball solidly (causing poor flight of the ball) when the hands come out of alignment, this provides superior feedback as it more closely simulates game play and is readily apparent to coaches. More significantly, improper rotation of the hands with the inventive practice bat cannot be accommodated by twisting or bending the torso, and thus avoids the development of such compensating habits that frustrate the development of superior skills and game performance.
 The motion of the movable handle toward the knob is sensed during the execution of a swing. In the simplest embodiment the hitter feel the movable handle contacting the leading hand at the moment they hit the ball. Accordingly, the practice batter can also observe if their hands have maintained the correct orientation through the swing, as the improper rotation of one hand with respect to the other will be apparent by simple inspection of the knuckle alignment. Thus, a batter can practice the correct method of hitting by verifying that his or her leading arm is doing most of the work prior to the ball hitting
 The practice bat shown in FIG. 1 is optionally formed by assembly of a shaft, barrel and knob, or by standard manufacturing, such as grinding a wood bat on a lathe or by rotary swaging or hammering of a metal bat, such as aluminum.
 Although the shaft 160 may be the same diameter as a standard bat handle, for familiarity of feel and ease of gripping, the shaft 160 is preferably made smaller such that when the handle 120 the feel of the bat 400 is similar to a standard bat.
 Although non-resilient grips may be used, a resilient grip 121 preferably is disposed on the outer surface of moving handle 120 provides better comfort for the user.
 As with the prior embodiment, the grips 414, 416 preferably have ridges 424 for the fingers, thereby allowing for proper alignment of the handles 406, 408 during swinging. However, in alternative embodiments the optional ridges can be replaced by a smooth, conforming, moldable, tactile or like gripping surface, as well as surfaces similar to a conventional bat grip.
FIG. 4 illustrates an alternative embodiment wherein a stop 461 is disposed on shaft 460 such that the hand gripping shaft 460 above knob 410 is protected from direct contact with movable handle 420 during the practice swing. In this embodiment it is desirable to provide the upper surface of stop 461 with an activation mechanism that is sensitive to contact with handle 420 to enhance either the hitter or coach's perception of the contact of movable handle 420 with stop 461. A variety of such mechanisms will be further described with respect to additional embodiments of the invention.
 Alternatively, as shown in FIG. 5 the resilient grips 521 may also have a flange 526 located on the bottom end. Thus either a stop 561 or fixed handle 562 is disposed between knob 510 or barrel 530 can contain a mechanism that provides the temporal indication of moving handles 526 position at the time of impact with the baseball. Thus the lower surface of flange 526 and the upper surface of either stop 561 or fixed handle 562 may be constructed from metals or other hard materials that produce an audible sound on impact, or may contain electromechanical contact or momentum change sensitive switches that activate other electronic or recording devices as further described.
 In other embodiments, the sound may be generated by an alternate mechanism. For example, an air bladder could be impacted and compressed by the projection on the handle. When the air bladder was compressed, air escaping the chamber could pass through a sound-generating orifice.
 To the extent it is also desirable to determine if the hands improperly rotate during the swing, the switch contact on either of these surface can be radially disposed with respect to shaft 560 such that a activation only occurs when a complementary feature or device in the opposing surface becomes radially coaligned as the moving hand rotates moving handle 520.
 Thus the feedback from the appropriate contact of the switch activating features associated with the moving handle and a stop or grip can both signals can be audible, vibratory or an electronic trigger signal. The electronic trigger signal might be used to activate a prerecorded sound on a microchip, or activate other devices or be recorded in a data log.
 As shown in FIG. 6, the barrel is preferably tapered, in which case a stop 628 is attached to the top of the shaft 660 to prevent the movable handle 620 from being forced up the widening section leading to the barrel 630 and getting stuck. The stop 628 may be attached in any suitable manner, including welding, adhesive, mechanical means.
 However, as shown in the various embodiments in FIGS. 7A, B and C the barrel may need not be tapered or conform to regular sizes or shapes. FIG. 7A illustrates an embodiment wherein the diameter of the moving grip and the grip area on shaft 760 above knob 710 is substantially the same diameter. In such a case it is preferable to omit a flange at the bottom of moving grip 720 to avoid pinching a portion of the leading hand's fingers between the flange lower shaft portions at the narrowing of the shaft. Alternatively, by also providing the lower stop, i.e. element 461 as shown in FIG. 4, the potentially for injury is minimized.
 In FIG. 7B the bat has a severe taper towards the end of the barrel 730 and the start of shaft 760 such that only a narrow shaded portion of the barrel retains the traditional or regulation diameter. The narrow portion of the barrel corresponds to ideal hitting region to provide further training and practice of both timing, arm and body motion to improve hand eye coordination.
 In FIG. 7C the bat barrel 730 is significantly narrower than the regulation bat to challenge the batters hitting accuracy, thus offering an alternative method to emphasize yet another aspect of hand eye coordination with combined training and practice of both timing, arm and body motion.
 In yet another embodiment the invention can be implemented via a kit comprising a movable handle assembly. FIG. 8A illustrates an alternative embodiment of the invention in perspective view of the invention in which the movable handle and the optional stop both comprise subcomponents adopted for attachment or retrofitting to an existing baseball bat that might be used in both practice and play, or interchanged between any of the bat shapes in the preceding Figures. FIG. 8B is a cross-sectional view of one embodiment of the movable handle. Movable handle 820 is composed is constructed optionally from 2 half cylinder segments 820 a and 820 b that separate at parting line 821 in FIG. 8A. FIG. 8C is a perspective view of the movable handle of FIG. 8B prior to application onto shaft 860.
FIG. 8D is a cross-sectional view of one embodiment of the optional stop for retrofitting to an existing bat. Halves 820 a and 820 b are connected by hinge 822 disposed opposite edges 821 a and 821 b that define parting line 821. Snap 822 extending from edge 821 b locks a mating feature or detent device provided in or on edge 821 a to secure segments 820 a and 820 b after inserting the open device in FIG. 8C over shaft 860.
FIG. 8E illustrates a preferred embodiment in which the kit also comprises either a grip stop 862 or lower grip for insertion onto shaft 860 above end knob 810 and moving handle 820. Grip stop 861 is optionally formed from two half cylinder segments 861 a and 861 b inside surface 861 c and 861 d of grip stop 861 are preferably deformable rubber or similar material for securing the grip stop 861 to shaft 860 via the frictional forces exerted by compressing surface 861 c and 861 d against the shaft. Halves fit via optional mating features 864′ and 864″ that extend from half 861 b and fit bores 863 and 863″ on half 861 a. Halves 861 a and 861 b are secured together to compress surface 861 c and 861 d via screws 866′ and 866″ that penetrate bores 865′ and 865″ in half cylinder 861 a such that they reach matching threads 862′ and 862″ formed in half cylinder 861 a.
FIG. 9 illustrates a non-limiting embodiment for incorporating various sensing and signaling devices into the barrel of the bat. The shaft 960 is centered and secured to the barrel 930 by a collar 922, which is held fixedly in place by a setscrew 921. The rigid shaft 960 is also fastened to the top cover 962 of bat barrel 930 by a screw 914 as it passes through a bushing 916. The shaft 960 is optional fixedly secured to non-movable, fixed handle 911 by adhesive or other known means. Alternatively, shaft 960 is secured to knob 910. Movable handle 920 has a brass inner tube 928 that disposed around shaft 960 for sliding thereon. The brass tube 928 can also be constructed of rigid plastic, such as nylon, or other sturdy metals and materials having a low coefficient of friction with respect to the shaft material for sliding thereon. A rubber or other resilient grip 923 surrounds the brass tube 928 and terminates at one end in a flange 912. Thus impact or vibration sensor 931 is disposed inside bat barrel 930 between shaft 960. Electrical signal leads 932 pass either along or through shaft 960 to handle portion 911. Handle 911 may comprise further circuitry or electronic components 933 and/or 934 for receiving, processing or routing multiple signals received from sensor 931 or switch 913. Alternatively, electronic components 933 can produce an audible or vibratory signal. Switch 913 is optionally a pressure sensitive or momentary contact switch disposed within handle 911 and is activated by either the contact of flange 912 or a pin 924 radially disposed about flange 912 to indicated rotation of the finger or knuckle positions on resilient grip 923.
 Alternatively, a second switch type sensor ( not shown) similar to switch 913 can be disposed in fixed handle 911 that is activated by contact of flange 912 independent of the rotation of grip 923 about the cylindrical axis of bat 900.
 Thus one or more of sensor 931 and switches in handle 911 can be connect to an alarm circuit for producing an audible, vibratory or electronic trigger signal for comparing the position of the movable handle 920 at the moment the bat contacts the ball. Thus component 933 can accept one or more trigger signal for data logging in an electronic storage media any of events of hitting ball, grip contact or grip rotation relative to shaft. Alternatively the trigger signal produced by component 933 can activate one or move still or video cameras to record an image of the hitter. Thus by examining this data log and/or picture the hitter or coach can ascertain if the practice is improving the hitting performance by observing trends over the practice session, a positive trend being a continued reduction in the time lag between hitting the ball and the moving handle contacting the lower handle or an equivalent stop.
 Further, the photographic record of swing, as activated by ball impact or handle movement provides an opportunity for additional coaching and correction of hitting techniques for instructional purposes. The camera may be activated via electronic signal transmitted directly by a wire extending from handle 911 at connector 934, but preferably via an optical signal, received by a photocell, or characteristic sound produced by electronic component 933. A particularly convenient form of a camera is a commercially available Personal Digital Assistant (PDA) as it can also serve as a general purpose computer and electronic data storage device for data logging purposes. Alternatively the Electronic components attached to the bat, moving handle or fixed handle/grip or stop can be provided as part of a retrofit kit.
 Alternatively, connector 934 can be port for connecting headphones so that the batter can hear an audible signal without distraction from background noise.
 Many features have been listed with particular configurations, options, and embodiment. Anyone or more of the features described may be added to or combined with any of the other embodiments or other standard devices to create alternate combinations and embodiments.
 Although the examples given include much specificity, they are intended as illustration of only a few possible embodiments of the invention. Other embodiments and modifications will, no doubt, occur to those skilled in the art. Thus, the examples given should only be interpreted as illustrations of some of the preferred embodiments of the invention, and the full scope of the invention should be determined by the appended claims and their legal equivalent
 While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.