Patent Publication Number: US-8986128-B2

Title: Golf swing practice apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This invention is a continuation-in-part of U.S. patent application Ser. No. 12/815,664, filed Jun. 15, 2010; the contents of which are herein incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to golf swing practice apparatuses, and more specifically to a golf swing practice apparatus including a rotating drum having an internal optical sensor mounted to a swivel and capable of detecting changes in swivel position for use in simulating a trajectory of a struck golf ball. 
     BACKGROUND OF THE INVENTION 
     The game of golf is played on a golf course which usually has eighteen holes. Each hole is a selected distance from a tee-box. A golfer initially hits the ball toward a green that provides a hole into which the ball is to be ultimately directed. In order to reach the green, the golfer employs clubs, either woods or irons, which have different lifts and weight so that the ball flies a calculated distance. Once on the green, the golfer uses a putter to roll the ball until it is ultimately hit into the hole. 
     It is known that a golfer&#39;s game can be improved by practicing hitting the golf ball. While it is relatively easy to practice putting, it is more difficult hitting longer golf shots such as would occur from the tee-box or fairway to the green. This practice hitting or driving is most frequently done at driving ranges. However, using a driving range can be time-consuming, expensive and inconvenient. Additionally, since driving ranges are located outdoors, bad weather may prevent their use. 
     In light of these difficulties, several golf swing practice devices have been developed to be utilized in a confined area. Such devices include tethered golf ball trainers, laser alignment club trainers, catch nets, and sensor-driven computer simulation systems. 
     Tethered golf ball trainers are provided by U.S. Pat. Nos. 2,656,720, 4,958,836, 5,460,380, US 2005/0107179, D353,179 and D500,544. Tethered trainers provide the opportunity to use a normal golf club to practice swinging at a golf ball. However, their tether and frame structures often cannot withstand the forces associated with club impact at club head speeds above 70 miles per hour. Additionally, missed swings striking the tether cord may result in lassoing of the tether cord around the golf club head, which can damage the golf club. The club head speed of an average golfer&#39;s swing is approximately 80 to 95 miles per hour. However, the speed of an average touring professional golfer&#39;s swing is approximately 110 to 125 miles per hour. 
     Laser alignment club trainers are provided by U.S. Pat. Nos. 5,165,691, 5,217,228, 5,435,562, 6,059,668, 6,458,038, 6,872,150 and US 2009/0215548. Laser alignment club trainers allow a user to visualize the theoretical path of a golf ball based on the orientation of golf club head. However, such trainers require special golf clubs with lasers mounted on or in the shaft or club head. 
     Sensor-driven computer simulation systems and catch nets are provided by U.S. Pat. Nos. 4,327,918, 4,343,469, 4,437,672, 4,451,043, 5,056,791, 5,437,457 and US 2007/0224583. 
     Sensor-driven computer simulation systems simulate real play by employing a series of optical sensors which gather information about a swing, computing the theoretical path of the golf ball using such information, and displaying the path to a user. However, simulation systems and catch nets are expensive, difficult to install, and require a large space. Additionally, systems employing catch nets require a user to fetch the ball and reset it after each swing. 
     As such, it may be appreciated that there continues to be a need for a new and improved home-use golf swing practice apparatus which can safely accommodate swings at club head speeds in excess of 70 miles per hour without employing large catch nets or expensive sensor driven computer simulation systems. 
     SUMMARY OF THE INVENTION 
     The present invention addresses the deficiencies inherent in current golf practice devices by providing a golf swing practice apparatus which includes an optical sensor mounted on a swivel within a rotating drum. More specifically, a first aspect of the present invention provides a golf swing practice apparatus which includes a rotating drum having an optical sensor mounted inside the drum that is capable of swiveling in a direction perpendicular to the rotational direction of the drum and capable of detecting a change in swivel position or swivel angle; an elongated cord including a proximal end secured to the drum and a distal end secured to a golf ball; a base member having an impact area over which a user may swing a golf club; a frame structure secured to the base member and to the rotating drum whereby the frame structure holds the rotating drum in an elevated position above the impact area; and a consol for optionally calculating and displaying swing data. The apparatus calculates predicted trajectory information of the golf ball when leaving the golf club swung by the user by converting a detected change in swivel position to a corresponding ball angle. 
     Data from the optical sensor is preferably wirelessly transmitted to the console and the console may display an approximate angle at which the ball left the users club head. In addition, a series of light emitting diodes (LEDs) can display the predicted trajectory information by selectively lighting at least one LED. 
     The golf swing practice apparatus can also include a means for raising the impact area after the golf ball is struck by the user to interrupt rotation of the golf ball. 
     In some embodiments the apparatus includes a means for measuring forces on the rotating drum or speed of rotation caused by the motion of the golf ball after the golf ball is struck by the user; a means for computing a theoretical spatial location relative to a fairway to which the golf ball would travel if the golf ball were not tethered to the rotating drum; and a display for displaying a theoretical spatial location to the user. In some embodiments the means of measuring the speed of rotation of the rotating drum includes a magnet secured to the rotating drum; and a magnet sensor secured to the frame structure, which is capable of monitoring rotation of the magnet. 
     In another aspect of the invention an optical drum for use with a golf swing practice apparatus is provided, which includes a drum core; a swivel ring positioned around the drum core and capable of swiveling perpendicular to a rotational direction of the drum, wherein the swivel ring includes an optical sensor capable of detecting a change in swivel position or angle; a tether means for tethering a golf ball to the center swivel ring; and a wireless transmitter or electronic circuitry to electrically transmit the change in swivel position to a receiver. 
     In another aspect of the invention a base member for use with a golf swing practice apparatus is provided, which includes an impact area at least partially detached from a surrounding golf base, wherein the impact area provides surface for impacting a golf club during a golf swing and the surrounding base provides a surface on which the user addresses a golf ball; and a means for raising the impact area from the surrounding golf base. In some embodiments, the impact surface includes a retractable center flap attached to an attachment site on a slide mechanism of the means for raising the impact area, which induces raising of the impact surface upon sliding of the sliding mechanism. In some embodiments, a push/pull lever bracket mounted on a bottom side of the mat provides a mechanism for raising the impact area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Those of skill in the art will understand that the drawings, described below, are for illustrative purposes only. The drawings are not intended to limit the scope of the present teachings in any way. 
         FIG. 1  is a front perspective view of an embodiment of a golf practice apparatus including a laser generating means  102  for visually monitoring the path of a golf ball  202 . 
         FIG. 2  is a side perspective view thereof. 
         FIG. 3  is an enlarged top perspective view of one embodiment of rotating drum  101 . 
       FIG  4  is a bottom perspective view thereof. 
         FIG. 5  is an enlarged front perspective view of one embodiment of base member  301  showing a raised impact area  302 . 
         FIG. 6A  is an enlarged front elevational view of one embodiment of elongated cord  201  and golf ball  202  and  FIG. 6B  is a side elevational view thereof. 
         FIGS. 7A-B  show an elongated cord  201  attached to a D-ring connector  206 , which connects to an adapter  207 . 
         FIG. 8  is perspective view demonstrating the positioning of a slide mechanism  314  positioned underneath an impact area  302 . 
         FIG. 9A  is a schematic showing a slide mechanism  314  and cable  312 .  FIG. 9B  depicts a motor  310   b  coupled to motor circuitry  310   c.    
         FIG. 10  is a perspective view demonstrating a raised impact area  302 . 
         FIG. 11  is a perspective view of another embodiment of a golf apparatus  500  including optical drum  501 . 
         FIG. 12A  is a perspective view of an optical drum  501  showing the inner optical sensor  502 .  FIG. 12B  is a cutaway view of an optical drum showing an optical sensor  502 .  FIG. 12C  is an exploded view of the optical drum showing the optical sensor  502 .  FIGS. 12D and 12E  are schematics depicting operation of the optical sensor  502  against a reflective drum slot  510 . 
         FIG. 13  is a front elevational view of an optical drum  501  showing pin  507 . 
         FIG. 14  is a partially exploded schematic depicting the drum core  506  with swivel ring  504 , end cap  505  and cover  508 . 
         FIG. 15A  is an elevational view of an optical drum  501  showing a swivel ring  504  and swivel distance  212 .  FIG. 15B  is a schematic showing swivel of a ball  702  and elongated cord  601 . 
         FIG. 16  is a cutaway view showing end cap  505  with drum circuitry  512 . 
         FIG. 17A  is a front elevational view of a consol  902 .  FIG. 17B  is a cutaway view showing consol circuitry  903 .  FIG. 17D  shows a display screen  906 . 
         FIG. 18  is a front elevational view of the frame base  950  with LEDs  954 . 
     
    
    
     DETAILED DESCRIPTION 
     The invention provides a golf swing practice apparatus that determines a trajectory of a struck golf ball and displays the results for viewing by a user. This is accomplished in part through the use of a rotating drum that is suspended above a platform and tethered to a golf ball. In one embodiment, the rotating drum includes a plurality of laser generating means that project light outward and thus permits the user to visually determine whether the ball trajectory is straight, left of center, right of center and like by visually monitoring the projected light beams. In a second embodiment, the rotating drum includes an internal optical sensor, which is mounted within the optical drum on a swivel. By mounting the optical sensor on a swivel the optical sensor itself detects changes in swivel position or angle, which corresponds to theoretical ball trajectory. Thus, the optical sensor detects left or right pivoting of the tethered ball and thus monitors whether the ball trajectory is straight, left of center, right of center and the like. Ball trajectory data can be combined with rotational velocity or force measurement to determine the distance and thus virtual position of a struck ball. Measurement of predicted ball speed is accomplished by rotational measurement of the drum. 
     Referring generally to  FIGS. 1-6 , a first aspect of the present invention provides a rotating drum  101 , an elongated cord  201 , a golf ball  202 , a base member  301 , and a frame structure. Rotating drum  101  includes a plurality of laser generating means mounted thereon. Elongated cord  201  includes a proximal end secured to rotating drum  101  and a distal end secured to golf ball  202  whereby golf ball  202  is tethered to rotating drum  101 . Base member  301  includes an impact area  302  over which a user may swing a golf club. The frame structure includes frame structure base  401  and frame structure arm  402 . Frame structure base  401  is secured to base member  301  and frame structure arm  402  is secured to rotating drum  101  whereby the frame structure holds rotating drum  101  in an elevated position above base member  301 . Rotating drum  101  is secured to frame structure arm  402  whereby rotating drum  101  can rotate freely about frame structure arm  402 . Rotating drum  101  and golf ball  202  rotate around frame structure arm  402  when golf ball  202  is struck by a user to impart flight thereto. In some embodiments, while rotating drum  101  and golf ball  202  rotate around frame structure arm  402 , at least one laser generating means  102  generates a laser beam which propagates substantially parallel along the path of golf ball  202  and at least one laser generating means  103  generates a laser beam which propagates parallel to a theoretical path of a fairway. 
     In some embodiments, elongated cord  201  is doubled on itself to define a distal cord loop and the distal cord loop passes through two holes in golf ball  202  to secure golf ball  202  to elongated cord  201 . Preferably, the two holes are located on golf ball  202  at an angle relative to each other between 45° and 90°. Preferably, elongated cord  201  is a 4 mm nylon rope doubled on itself and golf ball  202  is a standard two-piece golf ball. Preferably, a distal portion of elongated cord  201  is surrounded by a resilient structure  203 . Preferably, resilient structure  203  is 130-150 mm in length and is constructed of a polymer, which can be opaque but is preferably transparent. Exemplary polymers include polypropylene, a variety of rubbers, and the like. In some embodiments two golf balls with elongated cords of different lengths are provided; one 450-460 mm long for use with woods and one 475-485 mm long for use with irons. 
     The elongated cord  201  can be connected to the drum  101  using a variety of approaches. In some embodiments, the proximal end of elongated cord  201  is threaded in a figure 8 pattern through a female insert  204 . The proximal end strands of the cord  201  are then crimped together with a steel clip  205 . Female insert  204  threads into a male insert  104 , as discussed below. Preferably, female insert  204  and male insert  104  are constructed of steel. 
     Another approach is shown in  FIGS. 7A-B , which shows an elongated cord  201  coupled to a D-ring connector  206  that can selectively connect to an adapter  207 , preferably having at least two apertures positioned one above the second to provide at least two ball heights, such as a first higher ball height for woods and a second lower ball height for irons. Alternatively, providing at least two apertures permits the user to compensate for stretching of the cord  201 , which depending on its materials may occur during the life of the device. Distances between the center of the two apertures can vary but in some instances is between about 10 mm and 40 mm but more preferably about 15 mm to about 35 mm when selecting between a wood configuration or an iron configuration or in some instances less than 10 mm when compensating for a stretched cord  201 . The skilled artisan will appreciate that by adding additional apertures and reducing their diameters the distances between neighboring apertures could be decreased and thus precision of ball positioning can be increased. 
     Referring to  FIG. 3 , in some embodiments, the plurality of laser generating means are laser generating diodes. Preferably, the plurality of laser generating means include three laser generating means—one laser generating means  102  and two laser generating means  103 . Preferably, laser generating means  102  and  103  illuminate only when rotating drum  101  is rotating, which saves battery life and prevents the laser beams from distracting the user at address. As rotating drum  101  rotates around frame structure arm  402 , laser generating means  102  projects a green laser beam which follows the plane of rotating golf ball  202 . Concurrently, laser generating means  103  project two red lines which simulate the path of a fairway. The resulting visual cue, which appears as three continuous laser beams on the floor, ceiling and adjacent walls, provides instant visual feedback to the user as to how square or straight golf ball  202  was hit at impact. If the green laser line stays within the two red laser lines, then the user knows the ball was hit straight. 
     Turning to  FIG. 4 , in some embodiments, rotating drum  101  includes a drum core  108  which rotationally engages frame structure arm  402 , a center swivel ring  106  which encircles drum core  108 , and a drum cover  109  which is affixed to drum core  108  and covers drum core  108  and center ring  106 . Referring to  FIGS. 3 and 4 , center swivel ring  106  can move from side to side over drum core  108  along the axis of rotating drum  101 . Laser generating means  103  are mounted on drum core  108  perpendicular to the axis of rotating drum  101  such that laser generating means  103  project two red lines perpendicular to the axis of rotating drum  101  to outline a fairway. Laser generating means  102  is mounted on center swivel ring  106  and the proximal end of elongated cord  201  is secured to center swivel ring  106  such that the forces applied by rotating golf ball  202  cause center swivel ring  106  to move from side to side over drum core  101  and the green line projected by laser generating means  102  to follow the plane of rotation of golf ball  202 . Drum cover  109  includes apertures exposing laser generating means  102  and  103  and male insert  104 . Male insert  104  is secured to center swivel ring  106  by means of a pin  107  and is located in a crevice along a portion of the circumference of center swivel ring  106 . Elongated cord  201  is secured to rotating drum  101  by means of female insert  204  which threads into male insert  104 . Male insert  104  can swing freely in the crevice in directions perpendicular to the axis of rotating drum  101  to absorb ball impact forces. Springs  105  may be secured to either side of male insert  104  and to the ends of the crevice to further absorb impact forces as shown in  FIG. 4 ; however as picture in  FIG. 7B , impact bumpers  210  may be provided as an alternative to springs or in addition to springs. 
     In some embodiments, the frame structure is constructed of steel. Preferably, frame structure arm  402  is height-adjustable and is constructed of solid steel which can safely withstand impact and centrifugal forces induced by a 145 miles per hour swing. 
     In some embodiments, the frame structure includes an upper frame structure  404  affixed at a proximal end to frame structure base  401  and at a distal end to a display means  403 . Display means  403  may display any or all of the following: club selection, ball flight distance, club head speed, ball angle, driving accuracy percentage, total swings, best shots, and averages. 
     In the some embodiments, base member  301  is a two-layered mat. The top layer is a turf mat and the bottom layer is a 3-7 mm rubber mat which adds rigidity and cushions a swing impact. Both layers may be soft and foldable. Alternatively, the bottom layer may be a constructed of rigid plastic. 
     As shown in  FIGS. 5 and 8 , in some embodiments, preferably base member  301  includes a raising means capable of raising impact area  302 , wherein the raising means raises impact area  302  after golf ball  202  is struck by the user to interrupt the rotation of golf ball  202 . Preferably, the raising means raises impact area  302  after golf ball  202  has made several revolutions. This can be accomplished by including programming which counts rotations or revolutions of the drum  101  and thus upon equaling a predetermined value the impact area  302  is raised. Counting revolutions can be performed by counting the passing of a magnet  110   b  with a magnet sensor  110   a  as shown in  FIG. 2 . Alternatively, once rotation begins a timer may provide a timed delay for initiating raising the impact area  302 . In any event, a raised impact area  302  is provided to slow or stop the golf ball  202  and sets it for the next swing. Accordingly, the user need not move from his stance between swings.  FIGS. 1 ,  2 , and  5  show impact area  302  in a raised position.  FIG. 5  shows raised impact area  302  interrupting the rotation of golf ball  202  after golf ball  202  has made several revolutions. Generally the raising means lowers the impact area  302  after a predetermined time period, which in some embodiments can be increased or decreased through programmed menu options offered to the user. In other embodiments the impact area  302  is lowered once rotation of the drum  101  meets a predetermined rotational threshold. For instance, once the drum  101  stops rotating or sufficiently reduces rotational speed, the impact area  302  may be lowered. This can be accomplished by timing rotations or by detecting when rotation has stopped or substantially slowed. Consistent with prior descriptions, monitoring rotation can be accomplished using a magnet sensor  110   a  that detects the rotational passing of a magnet  110   b  as shown in  FIG. 2 . 
     In some embodiments, the impact area  302  is a three-sided flap cut out from a center portion of the top layer of base member  301 . In some embodiments, a means for raising the impact area  302  includes an elastic band which is attached to the underside left end of the flap. The elastic band stretches across base member  301  (the right end) and anchored. The tension of the elastic band causes the flap to bow upwards in the center. 
       FIGS. 8-10  depict a preferred approach to regulating the raising and lowering of impact area  302 . Specifically, a means for raising the impact area can include a motor  310   b  stored in a motor housing  310   a  that is attached to a cable  312 , which itself runs from the motor  310   b  underneath or within base member  301  to a slide mechanism  314  that is mounted to the base member  301 , and underneath the impact area  302 . The slide mechanism  314  includes attachment site  316 , which attaches to the flap at the impact area  302 . As shown in  FIG. 8  and in view of  FIGS. 9A and 9B , when the motor circuitry  310   c  is not activated (off position) the motor cable  312  is unwound or spooled out, which releases the slide mechanism  314  to the left, thus flattening the bow and lowering the flap to a flat position, flush with the rest of the top layer of base member  301  thereby forming a flat impact area  302 . When the motor circuitry  310   c  is activated, the cable  312  is wound tight by the motor  310   b  thereby increasing tension of the slide mechanism  314  and thus the flap is pulled to the right at the attachment site  316  which causes the flap to bow upwards and raise the impact area  302 . The skilled artisan will appreciate variations exist for the means for raising the impact area  302 . For example, suitable mechanisms can be formed using various levers, springs and the like, which provide substantially the same effect and thus would also be encompassed by the invention. 
     Returning to  FIGS. 1 and 2 , in some embodiments, the invention includes a ballast, preferably in the form of a water tank  303 , secured to base member  301  to provide stability to the frame structure when water tank  303  is filled with water. Preferably, water tank  303  is a specially designed 17 gallon water container which securely anchors base member  301  to the ground or floor when filled to accommodate the centrifugal forces on the ball-tether system. The combined weight of base member  301  and 17 gallons of water provides over 170 lbs of weight to offset the impact and centrifugal forces of a 145 mile per hour swing. The container is easy to fill and empty, facilitating the transport of the present invention from place to place, such as from the basement or garage out to the patio or lawn. Naturally, one could also place other media in the water tank  303  such as sand, gravel and the like or provide other means for reducing movement of the apparatus; however, water tends to be the preferred media and approach. The water tank also doubles as a packaging box or space, where all of the device&#39;s disassembled parts and components can be placed or packaged, for storage or shipping. 
     In another aspect of the invention a golf apparatus  500  is provided substantially as shown in  FIGS. 11-18 , which includes a rotating optical drum  501 , an elongated cord  601 , a golf ball  702 , a base member  801 , a consol  902  and a frame structure  890 . As shown in  FIGS. 12A and 12B , within optical drum  501  is an optical sensor  502 , which as shown in  FIG. 14  is positioned along a swivel ring  504 , which itself is positioned around and mounted to drum core  506  by pins  507  (also shown in  FIG. 13 ), which permit swiveling of the swivel ring  504  in a direction that is perpendicular to the rotational direction of the optical drum  501 . 
     As can be seen in  FIGS. 15A and 15B , striking ball  702  with an open or closed club face causes ball  702  to move either left or right from a center path. Left or right movement of ball  702  is transferred through the elongated cord  601  causing swivel ring  504  to swivel either left or right in a direction opposite the ball  702  and along an arc path. Swiveling of the swivel ring  504  causes optical sensor  502  to rotationally swivel in combination with swivel ring  504 . Turning back to  FIG. 14 , swiveling of optical sensor  502  occurs in relation to drum cover  508 . Accordingly, by tracking movement across drum cover  508 , such as along an arc path of a drum slot  510  optical sensor  502  is capable of detecting a swivel distance  212  as shown in  FIG. 15A  thereby permitting calculation of a swivel angle and thus a trajectory vector of a ball  702  that differs from the rotational direction of the drum  501 . Accordingly, swivel angle can be used to calculate overall theoretical ball trajectory or the degree at which a club face is open or closed. 
     The skilled artisan will appreciate that as the optical drum  501  continues to rotate, the angle from center or the arc length will continue to lessen. As such, in a preferred embodiment, the maximum value corresponding to the maximum swivel angle or maximum off center ball trajectory is saved for display. This can be accomplished by measuring or recording the swivel that occurs during the initial rotation of the optical drum  501 . In some embodiments, a swivel is measured during a second rotation. In other embodiments a swivel is measured during a third rotation. In still further embodiments, the swivel is measured during two or more complete rotations and averaged to provide an average angle or average degree off center value. The skilled artisan will appreciate swivel measurement or detection can be initiated upon detection of rotation of the drum  501 , such as by incorporating a magnet sensor  110   a  that detects the passage of a rotating magnet  110   b  as shown in  FIG. 2 . 
     Optical sensor  502  may be formed in any suitable way, which permits optical sensor  502  to detect movement across drum cover  508 . In preferred embodiments, drum cover  508  includes a slot  510  that accepts optical sensor  502 . In preferred embodiments, optical sensor  502  includes a diode, such as a LED or laser diode to emit light against the inner surface of the drum cover  508 . The optical sensor  502  also preferably includes a corresponding sensor means to detect the emitted light thereby detecting movement of the optical sensor  502  and thus permitting ball flight angle to be accurately determined. 
     In some embodiments the optical sensor  502  is an optoelectronic sensor that operates akin to a video camera that takes rapid sequential images of the inner surface of the drum cover  508  and using digital image correlation, detects naturally occurring texture variations in materials or detects changes in a printed surface across the drum cover  508  and thereby is able to determine or measure the amount of swivel of the optical sensor  502  across the drum cover  508 . High speed camera imaging and digital image correlation is improving rapidly and thus such advances can easily be adapted into the optical drum  501 . Further, these technologies can be adapted from a variety of optical mouse technologies used in the computer arts, which track movement of the mouse across a surface, such as a desk. In related embodiments the optical sensor  502  detects shifts in wavelength of an emitted light due to the swiveling of the optical sensor  502  along the inner surface of the optical drum  501 . In preferred embodiments the inner surface is reflective to enhance reflection of the emitted light. 
     The skilled artisan will appreciate there are a number of variations to optical tracking methods and sensors, which can be used with the present invention. Preferred approaches are shown in  FIGS. 12C through 12E , the optical sensor  502  preferably includes a small emitting light source  576 , such as a LED, red in color. The LED emits light, preferably through a collimating lens  577 , which then bounces or is reflected off a reflective surface, such as the slot  510  along the drum cover  508  and is detected by a complementary metal oxide semiconductor (CMOS) sensor  578 . The CMOS sensor  578  sends each image reflected back to a digital signal processor (DSP) for analysis. Using thousands of images that the CMOS  578  sends to the DSP for analysis, the DSP is able to detect both patterns and images and can determine if the optical sensor has moved, at what distance it has moved and at what speed. The DSP can also determine coordinates that are then sent to the processor that the optical sensor  502  is hooked up to, such as within the drum  501  or preferably within the consol  902 . Such technologies can be adapted from optical mouse technologies used in the computer arts. 
     There are many benefits to using an optical based system to determine ball trajectory. For example, the optical sensor  502  has no moving parts, which increases reliability. Measuring movement using an optical sensor also provides a high degree of precision with recent improvements in optical tracking technologies. 
     As shown in  FIG. 14 , preferably the optical drum  501  also includes an end cap  505 , which as shown in  FIG. 16  may include drum circuitry, which itself includes a power source PCB  512  for supplying power to components within the drum  501  through power communication plugs  513 , such as to a wireless data transmitter  514  such as Bluetooth or other data frequency transmitters, the optical sensor  502 , and the like. The drum circuitry can also have a processor such as to process data from the optical sensor  502  or process rotational data, memory, batteries and the like. In some embodiments swing data can be stored in the drum  501  and downloaded to a remote computer for further analysis, data plotting in the form of graphs or the like using suitable software. In preferred embodiments trajectory data measured using the optical sensor  502  is transmitted wirelessly from the wireless data transmitter  514  to a consol  902 , which as shown in  FIGS. 17A-17C , can include consol circuitry  903  which can include a wireless receiver, a processor  905 , memory, power supply, such as battery and the like. The skilled artisan will appreciate that since ultimately degree off center will be displayed using data from the optical sensor  502  such calculations can be performed by the drum circuitry if equipped with a suitable processor followed by transmission to the consol  902 . Alternatively data can be transmitted by the wireless transmitter  514 , received by the consol  902  and the consol can perform any needed trajectory calculations using the processor  905  within the consol circuitry  903 . Such calculations can be performed using mathematical equations that consider the swivel angle, rotation speed, acceleration and direction, ball plane or the like as known in the computational arts. The skilled artisan will appreciate that the consol  902  can communicate with the drum  501 , the magnet sensor  110   a , the means for raising the impact area and the like to coordinate or instruct any needed operations and to make any needed calculations. As eluded to, consol  902  also includes a display screen  906 , which depicts various readouts, such as ball flight distance  906   a , club identifier  906   b , club head speed (CHS)  906   c , degree off center  906   d , total number of swings per session  906   e  and the like. The skilled artisan will appreciate that the consol  902  may permit the user to switch across various programming modes, select user data or average data and the like for further statistical analysis. In addition, by loading course information into memory of the consol circuitry  903 , such as distances, widths and like, which themselves can be modeled from global position satellite (gps) coordinates, the user can simulate playing any course. Accordingly, in some embodiments the display simulates a theoretical position on a simulated golf course, which can be updated with each swing by sequentially comparing or plotting ball vector information to a loaded map. 
     To further assist the user in recognizing the accuracy of ball strike, the frame base  950  may include a plurality of indicator lights, such as LED indicators  954 , which visually signal the degree at which the ball trajectory is off center. Non-limiting ranges contemplated can be between 0.25 to 5 degrees per LED position with 0.5 to 2.5 being preferred and 1 degree being most preferred. For instance, if the user hits the ball  702  square, a center green LED pair  954   g  will illuminate and the console display screen  906  will display a plus or minus angle from 0-2 degrees in a degree off center data  906   d  field. If the user hits the ball right 3 degrees, the console display screen  906  will display 3 degrees in the degree off center  906   d  field and the blue LED  954   b  will illuminate. As a further example, if a right handed hitter hits the ball 4 degrees to the left, the console display screen  906 , will display −4 degrees in the degree off center  906   d  data field and the yellow LED  954   y  will illuminate. The red LED  954   r  indicates anything over 5 degrees, or OB or out of bounds. 
     The skilled artisan will appreciate that a means of measuring the speed of rotation or acceleration of the optical drum  501 , which can be used to measure club head speed or predict a corresponding ball distance, can be accomplished using a variety of approaches such as by securing a suitable magnet in the optical drum  501  and a magnet sensor secured to the frame structure. Alternatively gearing can be joined to the drum  501 , such as on the drum core  506  to measure rotation or rotational speed. The skilled artisan will appreciate that rotational speed or acceleration can be converted to club head speed, a theoretical distance and when combined with vector information from the optical sensor  502  further detailed positioning can be determined such as distance from center of fairway, distance from pin, landing in virtual rough, sand trap, lake, hazard and the like. This theoretical spatial position can be calculated in consideration of vectors incorporating rotational speed and swivel angle and applying the results to a mapped course defined by Cartesian coordinates. Cartesian coordinates corresponding to a simulated golf course can be generated from gps coordinates of a known golf course as known in the computational arts. Thus, theoretical position can be compared with simulated course maps and the like. 
     Having described the invention in detail, it will be apparent that modifications, variations, and equivalent embodiments are possible without departing the scope of the invention defined in the appended claims.