Abstract:
A trainer is formed of a handle joined to an end of an elongated tubular chamber containing a charge of metal beads. A longitudinal tension rod unites chamber and handle to protect the integrity of the trainer and enable it to be constructed from light weight material such as PVC plastic tubing. The charge of beads weights the trainer to match the feel of a real club. The beads shift in the chamber during a practice swing so that the player sees, feels and hears the shift of the metal beads at appropriate points during the swing, to alert the player when he has swung with proper lag. The beads self-generate a signal by their relative movement in the tube, even without reaching an end of the tube. The player can adjust his swing in increments to alter the point at which the charge of beads shifts in the chamber.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention generally relates to games using a tangible projectile. More specifically, the invention relates to the game of golf and to a practice swingable implement or indicator associated with a swingable implement. In a further aspect, the invention relates to a device that is attachable to or integral with a swingable implement and that includes a swing or position indicator that provides an audible signal that is heard by the player. 
         [0003]    2. Description of Prior Art 
         [0004]    In the game of golf and in several other games that involve swinging an implement to strike a ball, the form of the swing must be correct for the player to hit the ball with consistency, accuracy and maximum distance. Consistency is important because golf is a progressive game, where one shot is the basis for the next at each hole, which requires that each shot be reasonably good. Accuracy in a golf swing is particularly challenging because a golf club is relatively long as compared to other popular swingable implements, such a baseball bats. Further, only the head of the relatively long club can strike the ball. Because the head is at the far end of the club from the player&#39;s grip, the head is the most likely portion of a golf club to be in the wrong position. A proper swing is necessary for the player to accurately and consistently deliver the club head to the ball&#39;s position, in order for the player to make a good shot. The swing not only must be accurate and consistent, but it must be delivered with power in order to drive the ball a fair distance on drives down the fairway. Accordingly, it is well recognized that a golf swing is a demanding motion that requires coordinated movement of the player&#39;s entire body. 
         [0005]    Developing a consistently good swing requires extensive practice, so that the player&#39;s body executes a proper swing each time. Players can practice in many ways. Playing the game of golf is helpful because all types of shots are encountered. Practice on a golf driving range is helpful for honing a particular part of the game. However, much of the time a player is not at a golf course or driving range but needs to practice his swing, regardless. To meet this need, various swing trainers are available. A player may wish to practice without regard to the weather, which results in the player&#39;s needing a swing trainer that is adaptable for indoor practice. An indoor swing trainer can be shorter than a normal golf club, to better allow indoor use with assurance that the shorter swing trainer won&#39;t strike walls and ceilings. 
         [0006]    In addition to enabling more practice time, a swing trainer can serve as a coach by alerting the player to the correctness of his swing. A good swing is formed by a series of properly coordinated, sequential motions. The swing starts when the player addresses the ball or the theoretical position of the ball, which entails standing in a proper position, facing the ball position, with a golf club held by a proper grip, and with the club head located slightly behind the ball. The player&#39;s shoulders are aligned parallel with the intended path of the ball. From this starting position, the player executes a backswing in which he brings the club head in a smooth arc around his trailing shoulder, bringing the club head to a position above and behind the leading shoulder. 
         [0007]    The backswing requires a cocking of the player&#39;s wrists as the club head is swung back. Typically, cocking takes place at approximately horizontal club position and is maintained throughout the remainder of the backswing. From the backswing stance, the player executes the downswing, in which the club stays in a cocked position until just after striking the ball. However, an important feature of the downswing is to maintain the wrists in cocked position until the downswing reaches a proper release point at which the wrists start to release, which is just after striking the ball and while the golfer&#39;s body weight is shifting forward to the leading leg. 
         [0008]    “Lag” has been defined as the period of time during a downswing when the wrists remain cocked while hands drop straight down and the body moves slightly open and forward, squaring the club face with the ball; followed by a point when the wrists uncock in the process of striking the ball. In abbreviated form, the term “lag” may refer to an element of a golf swing that manages hand and wrist motions in the described manner. Many golfers have difficulty achieving proper lag in their swings. It would be desirable to have a swing trainer that can assist a golfer in executing a proper swing with “lag” by providing audible, visual and kinesthetic signals when the golfer is properly or improperly swinging the trainer. The longer the wrists can stay cocked, the more energy can be transferred from the club to the ball. 
         [0009]    U.S. Pat. No. 5,634,856 to Rainey is an example of a golf swing trainer that is shorter than a standard length #8 iron golf club. This trainer is formed of a tubular body with a grip at one end and a free sliding bearing ball inside the tube. The weight can slide between a plug at the grip end of the tube and a stop at the end opposite from the grip. This trainer operates by selecting the available length of the tube over which the bearing ball slides. The length is determined by the transit time for the weight to slide from the plug to the end stop. This travel distance and weight are coordinated such that the weight strikes against the stop when the trainer is swung to the ball impact point of a properly executed swing. Thus, the length of the tube is selected to time the impact to occur at the precise bottom of a proper swing. The player can evaluate his own swing by judging how closely the audible signal sounds relative to the bottom point of the swing. However, this device fails to teach “lag” in the swing. The Rainey trainer uses high mass components, such as a single, large hardened steel slider to simulate ball impact at the bottom of the downswing. The high mass of the slider is insensitive to execution of a proper swing with “lag.” 
         [0010]    It is evident that variables in addition to tube length can influence when the Rainey weight will strike the end stop. Swing speed stands out as a variable that is likely to produce error. It would be difficult for the player to calibrate the Rainey trainer without having his own perfect swing as a reference point. Therefore, a problem with the Rainey approach is for the player to know when the trainer is properly adjusted to his own swing characteristics. 
         [0011]    A further problem with many trainers using a shifting slider is that the golfer&#39;s swing and the trainer&#39;s operation may be seemingly incompatible. This problem might result with a golfer&#39;s swing that is so rapid and powerful that the slider in the trainer does not move at all. This problem can be referred to as the power swing deficit. For example, in Rainey the starting position of the slider may be at the distal end of the trainer. A rapid backswing immediately followed by a rapid fore swing may result in the slider being centrifugally trapped at the distal end of the trainer, such that the trainer apparently fails to perform. In such a circumstance, it must be realized that a golf swing can appear to be proper and produce seemingly good strokes. However, in such cases the golfer is benefitting from his own power as a substitute for maximizing the inherent power that can be released with a better swing. 
         [0012]    Golfers practice their swings in many settings. For example, a golfer may practice at home or at a driving range, using his own clubs. Because golf clubs tend to be expensive and often are custom fitted to the individual golfer, golfers often have a strong affinity for using their own clubs. There can be a resultantly strong temptation for the golfer to practice with his own clubs, rather than purchase a trainer. To be accepted, a trainer needs to show its value in teaching features of the golf swing that practice with the golfer&#39;s own club does not teach. 
         [0013]    In convincing a golfer to practice with a trainer, it can be helpful if the trainer is less costly than a golf club. Thus, producing a trainer from inexpensive materials and commercially available components is an advantage, as compared to the use of custom roll formed metal parts as found in Rainey. The use of light weight materials such as plastics in the body of a trainer is another advantage, which permits the elements of the trainer that shift position to be a proportionately greater part of the trainer&#39;s weight. A trainer also should produce an easily generated and detected signal so that, for example, a golfer working to solve the power swing deficit will begin to receive a corrective signal even before his new swing is perfected. For this reason, a single high mass slider as found in Rainey may set too high a threshold before the trainer begins to deliver feedback. 
         [0014]    It would be desirable to have a trainer formed of a light weight plastic body, using a movable charge of small beads instead of a single high mass slider for sending corrective signals. 
         [0015]    It would be desirable to have a short swing trainer that delivers a signal indicative of the progress of the swing, rather than just the ball impact point. For example, a player should consider wrist action, with cocking and uncocking at suitable times. A player can improve his swing by learning to employ proper lag throughout his swing, thereby marshalling the power of his swing to maximize at the point of impact with the ball. 
         [0016]    To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the method and apparatus of this invention may comprise the following. 
       SUMMARY OF THE INVENTION 
       [0017]    Against the described background, the object of the invention is to provide a golf swing trainer that teaches the concept of “lag” in a golf swing. This concept is used by many, if not all, professional golfers. 
         [0018]    According to the invention, a golf swing trainer is considerably shorter than a real golf club, where real golf clubs might be as long as forty-eight inches. The trainer is formed of a handle joined to an end of an elongated plastic chamber, which may be transparent. The chamber contains a charge of small beads, BBs, ball bearings, or shot. The chamber and handle are united by a longitudinal tension rod that protects the integrity of the handle and chamber. The tension rod may be calibrated for weight of the charge according to depth measured on the rod. Although the trainer is considerably shorter than a real golf club, the charge of beads weights the trainer to a desired degree, such as to match the feel of a real club. The weight of a real golf club might be twelve ounces, with considerable variation above or below that weight to suit the user. However, because the weight of a golf club might be concentrated at the head, where it is swung on a long shaft, a shorter trainer may require greater weight to produce a similar dynamic feel. The volume of beads can be changed to alter weighting, such as for different golfers, i.e., men, youths and women. 
         [0019]    In use, the golfer swings the trainer like a regular club. The beads self-generate a signal as they move, without the necessity of striking an end of the chamber. Due to the self-generated signal, a golfer can both feel and hear any shift in position of the beads at various points during the swing, which tells the golfer when he has swung with proper lag. The beads self-generate a signal by their relative movement in the tube, even without reaching an end of the tube. The sound of the shifting charge of beads is an indicator of performance, although the feel of the beads is a substitute for audible signals among users who can&#39;t hear the moving charge, such as among users having limited hearing ability. Through feel and sound, the trainer helps the golfer to properly move a golf club through backswing and downswing, as well as to set, maintain, and release the golfer&#39;s wrists with respect to cocked position. 
         [0020]    The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention. In the drawings: 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0021]      FIG. 1  is an exploded view of the swing trainer. 
           [0022]      FIG. 2  is a side view of the swing trainer, showing the charge of beads in an unloaded position. 
           [0023]      FIG. 3  is a view similar to  FIG. 2 , showing the charge of beads in a travel position. 
           [0024]      FIG. 4  is a view similar to  FIG. 2 , showing the charge of beads in a loaded position. 
           [0025]      FIG. 5  is a first developmental view in the series of  FIGS. 5-10 , showing a player using the swing trainer in a position addressing the ball. 
           [0026]      FIG. 6  is a second developmental view of the series of  FIGS. 5-10 , showing the player using the swing trainer in a position of mid-backswing and showing the player&#39;s wrists having assumed cocked position. 
           [0027]      FIG. 7  is a third developmental view in the series of  FIGS. 5-10 , showing the player using the swing trainer in a position of full backswing with wrists still cocked. 
           [0028]      FIG. 8  is a fourth developmental view in the series of  FIGS. 5-10 , showing the player using the swing trainer in a position of initial downswing, and showing the wrists still cocked. 
           [0029]      FIG. 9  is a fifth developmental view in the series of  FIGS. 5-10 , showing the player using the swing trainer in a position of mid-downswing, and showing the wrists still cocked and the charge of beads initiating shifting movement toward the distal end of the trainer. 
           [0030]      FIG. 10  is a sixth developmental view in the series of  FIGS. 5-10 , showing the player using the swing trainer in a position of immediately after ball impact, with wrists uncocked and with beads thrown to the distal end of the chamber with a force that can be felt and heard. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    The invention is a golf swing trainer  10  that a player may use for practice to refine his golf swing into a consistently reproducible, power-releasing swing. The trainer  10  is sensitive to aspects of a golf swing that other known trainers do not meaningfully detect and respond to. Trainer  10  issues a visual, audible and haptic signal when the player swings with proper lag. In the context of this invention, the term, “lag,” refers to a period of time in a downswing when cocked wrists and hands drop straight down and the body position shifts to slightly open position and forward to square the club face with the ball. At that point the wrists uncock to strike the ball. The longer the wrists can stay cocked, the more energy can be transferred from the club to the ball. Thus, the trainer  10  teaches delayed uncocking of the player&#39;s wrists on the downswing. The trainer  10  is designed to teach a downswing where the player&#39;s wrists uncock after reaching the impact position with the ball. Accordingly, both the method and apparatus of the invention are directed toward improving a player&#39;s golf swing by helping to manage his swing during the period of lag. 
         [0032]    The trainer employs a large number of small weights such as a charge of beads or metal spheres that self-generate a training signal as they move en masse. By such self-generated signal, this charge can respond to stages of such a proper swing in order to guide the golfer to develop a progressively better swing. It is not necessary for the charge to shift into contact with a terminal wall of the trainer in order to provide an impact signal. Many players employ a swing that is a continuous fan motion that highlights ball impact at the bottom of the swing. Focus on the ball impact event can encourage the player to try to generate power by centrifugal swing speed, alone. Often a fan swing fails to observe optimum wrist action, where uncocking of wrists should not occur too soon. The swing trainer  10  responds to the timing of when wrists are uncocked to help the player position this event for maximum power in his swing. The swing trainer might issue additional audible and physical signals at other parts of the swing, such as at full backswing and at ball impact position, or at any position where the swing is improper. Of these signals, the lag signal is the goal for better and consistent golf for the advanced player. 
         [0033]    The swing trainer  10  is formed of two elements arranged in longitudinal series. As best shown in  FIG. 1 , a handle  12  is positioned at a proximal end or top end of the club, near where the player holds the trainer  10 . A tubular weight transfer chamber  14  is positioned at an opposite, distal end of the trainer. The two elements are longitudinally strung on a threaded rod  16  that places both elements in compression, prevents stress failure despite repeated lateral and longitudinal stress imposed by a shifting mass, enables construction using prefabricated plastic parts, ensures against joint failure, and secures the trainer against impact failure. The trainer  10  is able to employ a shifting charge of relatively high mass, bead-like components, which detects and responds to subtleties in swing motion, including lag. The response provides a signal to the player when wrists are cocked or uncocked at proper times, thereby helping the player to know when he has achieved correct form and to avoid practicing incorrect form. 
         [0034]    The swing trainer has a handle or grip  12 . The handle  12  has a core and a wrap that is applied around the core. Together, core and wrap simulate the grip of a typical golf club. The handle core may be formed of a rod or tube approximately ten inches in length, which is similar to the grip length of a golf club. The preferred material of the trainer grip is three-quarter inch PVC plastic pipe. This material offers the advantage of being a commodity that is not overly expensive and which is extremely lightweight. The covering wrap is a leather-like material to provide a similar feel to a regular golf club grip. 
         [0035]    The proximal end of the handle  12  is engaged with a proximal end cap  18 . The cap  18  is suitably secured to the proximal end of the grip, such as to the core, by a bonding agent or by friction. The cap  18  is a prefabricated plastic pipe cap that can be fastened to the pipe core by solvent welding or other means. A rod  16  is engaged with, through, or at the cap  18  in a manner that prevents the cap from lifting away from the end of the rod. For example, a fastener such as a mushroom-headed nut or an acorn nut  20  is threaded to the end of the metal rod  16  outside the cap to serve as a longitudinal retainer and compression element for the cap. Optionally, a relief element is used in association with the nut  20  to absorb shock and avoid excess compression on the cap. For example, the relief element may be a washer  22  placed under the nut and formed of compressible, resilient material such as rubber or elastomeric material. 
         [0036]    An opposite or distal end of the handle  12  is attached in longitudinal alignment with the proximal end of the tubular weight transfer chamber  14 . A suitable size for a weight transfer chamber  14  is about twenty-four inches in length and about one inch in diameter. A suitable junction connects the relatively larger diameter of the weight transfer chamber  14  with the relatively smaller diameter of the handle  12 . An example of such a suitable junction is a prefabricated, PVC plastic, three-quarter inch to one-inch coupler fitting  24 . The proximal end of fitting  24  is a junction that receives the distal end of handle  12 . The fitting may be secured to the distal end of the handle core by means similar to those described for securing cap  18  to the proximal end of handle  12 . 
         [0037]    An opposite end of fitting  24  is a junction that receives the proximal end of weight transfer chamber  14 . The fitting may be secured to the weight transfer chamber by threads, solvent welding, rod  16 , or any other means, including all methods described for securing cap  18  to handle  12 . The weight transfer chamber  14  may be a tubular plastic pipe, which may be formed of clear plastic to enable visual observation and measurement of the tube&#39;s contents. Where the tube  14  has a one-inch diameter, a reduction coupler fitting  24  may be available to interconnect the tube  14  with the handle core. If such a reduction fitting is not available, it may be fabricated from other standard, prefabricated plastic fittings. For example, a standard fitting size has a one-inch female slip socket and a one inch female threaded socket. Another standard fitting size has a three-quarter inch female slip socket and a one-inch male threaded end. The two slip sockets can be joined to the ends of respective tube  14  and handle  12 , while the two threaded ends can be joined by threaded engagement. Such a fabricated reduction fitting  24  is desirable because the threaded engagement provides at least one junction that can be opened for access to the interior of the tube  14 , if required. 
         [0038]    A distal end fitting or cap  26  is applied to the distal end of tube  14 . The end cap  26  may be secured to the end of tube  14  by any suitable means, including any of those described for securing cap  18  to handle  12 . Metal rod  16  is engaged with, through, or at the cap  26  in a manner that prevents cap  26  from separating from the distal end of the metal rod  16 . A mushroom headed nut or an acorn nut  28  is threaded to the distal end of the metal rod  16  outside of cap  26  to serve as a longitudinal retainer for cap  26 . At least one of the various suitable fasteners that can be applied to rod  16  can be adjusted to place the side walls of handle  12  and weight transfer chamber  14  in compression. 
         [0039]    During assembly of swing trainer  10 , a charge  30  of metal beads such as BBs, shot, or steel ball bearings is placed in the weight transfer chamber  14  and is sized to only partially fill the chamber so that the charge can shift from end to end within the chamber and generate an aural signal while shifting. Typically, when compacted at one end of the chamber, a charge will occupy a minor portion of the length of the chamber. As an example, the charge occupies about fifteen to twenty-five percent of the chamber length. The size or mass of the charge is coordinated with the size or musculature of the intended user. For example, when the user is a male of normal size, the charge may weigh about 14 ounces and the remainder of the trainer  10  may weigh about 20 ounces, producing an overall weight of 34 ounces. The charge  30  is composed of a large plurality of bead-like members, which typically will be steel balls, to enable the charge to self-generate readily perceived sounds as the charge moves in the weight transfer chamber. As an example, an ounce of a first brand of commercially obtained 4.5 mm steel BBs contained about forty pieces, while another brand of 4.5 mm BBs contained about one hundred pieces. Members of about 4.5 mm diameter are preferred because this size performs well and is inexpensive due to the ready commercial availability of BBs. These weights suggest that a charge formed of about 4.5 mm diameter balls will contain a hundred or more members or even a thousand or more. Other types of components may come in different sizes and different component weights. The charge should consist of a large plurality of component pieces, where the minimum is more than a dozen pieces to ensure that a perceptible aural result is self-generated by interaction between members during movement en masse. Likewise, the charge components are to be large enough or massive enough to self-generate a perceptible aural result by interaction between the members during mass movement. At the same time, the components should be small enough to move freely and without jamming between the rod  16  and the inner face of the tube  14 . In the format of the trainer structure, the example weight feels and performs typically to certain golf clubs used by men. If the user is smaller, such as a female or youth, the charge may be smaller in order to correlate the overall weight with certain golf clubs used by females or youths. 
         [0040]    After assembly, it remains possible to change the mass of the charge. Cap  26  or fitting  24  serve as means for selectively sealing and opening an end of tube  14 . Either may be threaded or simply attached to tube  14  by compression, such that either may be removed to open an end of chamber  14  even after remaining junctions may optionally have been permanently sealed, such as by solvent welding. An advantage of using rod  16  to capture and secure fittings  24  or  26  to the weight transfer chamber is that the fittings  24 ,  26  need not be permanently attached. Instead, the rod  16  can be released for removing the fittings  24 ,  26  to open the chamber and modify the charge of beads. For example, the distal end nut  28  may be removed and cap  26  may be removed, revealing the distal open end of tube  14  and allowing the addition or removal of charge members. Markings or indicia  31  may be incorporated into the structure of the weight transfer chamber to offer suggested fill levels of the charge  30  for different users, such as for men, women, or children. Suitable locations for such markings  31  are rod  16  or clear tube  14 . In this manner, the weight of the trainer  10  can be adjusted to suit the needs of different users, such as men, women, and children. The mass of the charge in a single trainer may be altered as described, or trainers may be manufactured containing various selectable charges that allow user choice. 
         [0041]    A typical charge  30  is composed of metal beads having a diameter of about three-sixteenths inch or about four millimeters. It is desirable for the charge  30  to constitute a large portion of the swing trainer&#39;s mass, which is aided by the ability to construct the body of the swing trainer from a light weight substance such as PVC plastic. It is desirable for the charge of beads or balls  30  to weigh almost as much as the remainder of the trainer, so that movement of the charge  30  is physically detectable when the trainer is used. As an example, the mass of a typical charge  30  for a swing trainer  10  intended for use by a male might be 14.2 ounces, while all remaining portions of the swing trainer might have a mass of 20 ounces. This charge  30  weighs about 40% of the total, while lighter charges might weigh twenty-five to thirty percent of the weight of the trainer. The use of plastic, or plastic pipe, to form grip and weight chamber contributes to the high ratio of weight located in the charge. The relatively large proportion of mass attributable to the movable beads self-generates a physical signal when the beads do, in fact, move. When the charge is reduced to a smaller mass such as 10 ounces, suited for smaller users, the charge remains a substantial proportion of the overall weight. 
         [0042]    In addition to providing a self-generated signal due to shifting mass, the beads self-generate an audible signal from the noise of rubbing against one another during any mass movement, even without the beads fully accumulating at an end of the tube  14 . Thus, end caps on the tube are not essential to performance of the trainer, although they contribute to the generated signals when struck by the shifting charge. The beads also provide an aural signal by non-movement or partial movement, which may indicate a condition in the golfer&#39;s swing if some other type of signal is appropriate at the point of the signal. In all of these ways, a charge of movable beads generates a greater number and variety of signals to the player, or self-generates a signal of greater sensitivity to detected conditions, than found with other types of moving weights. A further advantage of using rod  16  is that the rod is placed in tension, which creates a unique aural signal as the beads interact with the rod. 
         [0043]    The distal end cap  26  closes one end of the trainer while also closing one end of the weight transfer chamber  14 . Optionally, the opposite end of the weight transfer chamber can be closed to prevent the charge of metal beads from entering the hollow handle  12 . The proximal end of the weight transfer chamber can be permanently sealed by applying a suitably sized washer  32  against the proximal end of tube  14  and securing the washer by a threaded nut  34 . A suitable size for the washer  32  matches the size of the socket of coupler fitting  24  that receives the proximal end of tube  14 . 
         [0044]    The handle  12 , cap  18 , coupler  24 , tube  14  and cap  26  are mounted in end-to-end abutment so that these components establish a fixed column length that is not subject to further compaction of length. The nuts  20  and  28  are applied to the opposite ends of the threaded rod  16  to place the rod  16  in tension from end-to-end. The resulting structure is highly resistant to failure due to stress from swinging or due to shifting mass in the chamber  14 . The stability of the swing trainer  10  is great enough that substantially the entire trainer  10 , apart from the handle wrap, rod and minor hardware such as washers and nuts, can be manufactured from prefabricated plastic pipe and plastic fittings. Thus, tube  14  may be formed of one inch PVC plastic pipe. Handle  12  may be formed from three-quarters inch plastic pipe. The caps  18  and  26  and coupler  24  may be plastic fittings sized to fit the respective pipe ends. 
         [0045]    The charge  30  of metal beads can move through tube  14  over the full length of the tube, which may be about two feet.  FIGS. 2-4  show three possible positions of the ball charge  30  in the tube  14 , considering only the tube volume. In  FIG. 2 , the ball charge  30  has moved in the direction of arrow  36  to be concentrated at the distal end of the tube  14  in what can be called an unloaded position. In  FIG. 3 , the ball charge  30  is movable in either longitudinal direction within tube  14 , in the direction of either opposed arrow  38  or  40 . In  FIG. 3 , the ball charge  30  has moved in the direction of arrow  42  to be concentrated at the proximal end of the tube  14  in what can be called a loaded position. 
         [0046]    A normal golf swing often is broken down into five parts: address, backswing, downswing, impact, and follow through. Consideration of these five components of a golf swing will demonstrate how to swing with proper lag. With reference to  FIGS. 5-10 , the swing trainer  10  is used in a method of practicing a player&#39;s  44  golf swing and achieving proper lag. The trainer  10  reacts to the dynamics of a golf swing by shifting the charge of beads  30  to provide visual, audible and haptic signals. When a player has been provided with a trainer  10 , he can learn proper lag by following the sequence of motions suggested by  FIGS. 5-10 . 
         [0047]    A practice swing begins in the position of player  44  in  FIG. 5 , addressing the ball position with a back shoulder  46  and a forward shoulder  48  approximately aligned with the intended path of the ball. The trainer is in front of player  44  in downward position, as though addressing the ball. The charge of beads  30  is in unloaded position, at the distal end of chamber  14 . The player&#39;s wrists  50  are in uncocked position. 
         [0048]    In  FIG. 6 , the player  44  begins his backswing around his back shoulder  46 , bringing the trainer through an arc that extends from the theoretical position of the ball to the backside of the player&#39;s head. As the player raises the trainer through about one-half of this arc, he cocks his wrists as shown in  FIG. 6 . In addition, the charge of beads  30  shifts through a travel position to the loaded position at the proximal end of chamber  14 . The look, sound and feel of the shifting beads informs the player of the transfer of position, by the continuous noise of the self-generated signal due to shifting beads tumbling over each other and rolling against the chamber walls and tension rod  16 . The player also senses the change in position of the massive charge of beads. The backswing continues to the position of  FIG. 7 , where the distal end of trainer  10  is approximately behind the player&#39;s forward shoulder  48 . The player maintains his cocked wrists  50  as the backswing progresses. 
         [0049]    In  FIGS. 8-10 , the player executes the beginning of his downswing, approximately following the reverse path of the backswing. In  FIG. 8 , the player has brought the trainer around his back shoulder  46  with wrists  50  cocked. A key feature of the swing occurs between  FIGS. 8 and 9 . Rather than moving his hands in a free arc, the player drops his hands and wrists, while retaining a cocked position. This dropping of the hands and wrists prepares the club to be brought into contact with the ball with a release of maximum power. In contrast, a player bringing his hands through a free arc, which would uncock between  FIGS. 8 and 9 , loses a significant amount of power before reaching the ball position. The mass of small beads in the trainer is especially effective in signaling, by an absence of noise, that the hands are dropping in cocked position, rather than uncocking, between  FIGS. 8 and 9 . The presence of rod  16  in the weight transfer chamber  14  establishes an annular retention volume where the beads are concentrated in the weight transfer chamber, such that some beads can fall against the rod while other shifting beads fall against the walls of the chamber  14 . The two types of contact with different materials in different states of tension and compression establish a sound pattern that effectively signals when proper hand and wrist motion has been achieved. 
         [0050]    In  FIG. 9 , the player&#39;s hands have dropped, and his arms are nearly finished with their arc and are at the bottom of the swing. However, the player&#39;s wrists  50  remain cocked and the trainer is nearly horizontal, suggesting that the trainer still must turn through about 90° of arc. The charge of beads  30  largely remains in loaded position at the proximal end of chamber  14 . 
         [0051]      FIG. 10  illustrates impact position. The trainer  10  has returned to approximately vertical position, although the golfer&#39;s body is now in a forward shifted position and the trainer is in motion. To reach ball impact position, the trainer  10  has moved through approximately the final quarter arc of the downswing. At impact position, the player&#39;s primary action is to uncock his wrists  50  as he accompanies the uncocking with a forward shift of body weight to the player&#39;s leading leg. Thus, it is evident that the significant difference between  FIGS. 9 and 10  is wrist position rather than arm position. Where retaining cocked wrists  50  in  FIG. 9  allowed the beads  30  to remain in loaded position, the uncocking of the wrists  50  in  FIG. 10  has caused the beads to move through travel position and into unloaded position. The beads have been thrown to the end of the chamber with a force that can be felt and heard while the position of the beads can be seen. Thus, the trainer delivers its signal in three modes, by being heard, felt, and seen. The final motion caused by uncocking the wrists  50  delivers power to the swing and takes place almost entirely at the ball impact position. 
         [0052]    The trainer  10  is configured to resemble a golf club in weight and feel, while being shorter that a typical club in order to achieve several advantages. One advantage is that the swing trainer  10  can be used in many indoor locations where the length of a normal golf club would prohibit use. Another advantage is that the swing trainer is more convenient to carry and transport than a typical golf club. It can conveniently accompany the player on travels so that he can maintain his golf swing on a daily basis. Finally, the length of the trainer is compatible with the timing of bead travel in the chamber  14 . 
         [0053]    The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be regarded as falling within the scope of the invention as defined by the claims that follow.