Patent Publication Number: US-7594858-B2

Title: Golf swing practice system

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119 
   The present Application for patent claims priority to Provisional Application No. 60/717,927 entitled “Golf Swing Training System”, by Thomas D. Hauk, filed Sep. 16, 2005, and expressly incorporated by reference herein. 

   BACKGROUND 
   1. Field 
   Various embodiments of the invention pertain to golf swing practice/training devices and, in particular, to a device providing a realistic practice target that, when struck, provides an indication of the position, direction, orientation, and/or strength of the golf swing. 
   2. Background 
   When playing golf, it is important to swing the golf club to provide maximum control over the direction and distance that the impacted golf ball travels. A need exists for golf practice apparatuses which provide useful, quick and accurate information to the golfer as to the quality and characteristics of a practice swing. These apparatuses should be designed and constructed to not only be sturdy to survive numerous impacts of the golf club head, but also to be easy to use. 
   Some prior art golf swing practice devices fail to provide a realistic swing target and/or accurate feedback of direction, orientation, and/or strength of the golf swing. 
   U.S. Pat. No. 1,363,446, by E. J. Vogel, describes a device including a substitute golf ball coupled to a mat by a substantially vertical tongue that flexes when the substitute golf ball is struck by a golf club. This device fails to provide feedback to a player about the direction, orientation, and/or strength of the golf swing. 
   U.S. Pat. No. 1,733,767, by L. E. Yaggi, describes a golf swing practice device including a supporting stake and a golf ball target coupled to the supporting stake by a ball-and-socket mechanism. When struck by a golf club, the golf ball target bends at the ball-and-socket point to indicate the direction of swing. The player must determine the rotation of the bent practice golf ball to ascertain whether the practice golf ball was struck straight or at an angle. This device fails to ascertain whether the target golf ball was struck high or low, the relative strength of the swing, and whether the practice golf ball was struck by the sweet spot of the golf club. Additionally, another disadvantage of this device is that the player must manually reset the practice golf ball every time. 
   U.S. Pat. No. 2,490,409, by P. H. Brown, merely describes a target golf ball that can be secured to a practice surface and flexes when struck by golf club. This target golf ball is not a realistic golf ball target and fails to provide any indication of the position, direction, orientation, and/or strength of the golf swing. 
   U.S. Pat. No. 5,451,059, by Weis, discloses a golf ball practice target having a substantially vertical support that, when struck, causes the golf ball practice target to return to its rest position. A hole at the center of the golf ball practice target is used to provide an audible indicator of a proper swing. However, as with other prior art, this golf ball practice target fails to provide any indication of the position, direction, orientation, and/or strength of the golf swing or whether the golf club struck the golf ball practice target on the club head&#39;s sweet spot. 
   U.S. Pat. No. 6,569,026, by Weis, discloses a golf swing practice apparatus having a golf ball target mounted on a vertical support that flexes when the golf ball target is struck by a golf club. The golf ball target includes a pointer that aligns itself with the direction of the golf club swing, thereby providing an indication of the swing. However, this device is inaccurate and fails to provide any indication of the position and/or strength of the golf swing or whether the golf club struck the golf ball practice target on the club head&#39;s sweet spot. 
   U.S. Pat. No. 6,659,775, by Moy, discloses a golf swing practice apparatus having a ball support having marking tabs along the upper edge of the support. In theory, when a golf ball mounted on the ball support is struck by a golf club, the marking tabs leave a mark on the golf club face. However, this device does not work unless the ball support is struck and, because the markers are offset from the golf ball surface, also fails to provide an accurate indication of how the ball is struck. 
   SUMMARY 
   Disclosed herein is a golf swing practice apparatus including a golf ball simulation target coupled to an anchor for anchoring the target to a support surface. This flexible target may include a round golf ball simulation target unit with a connector arm. The end of the arm opposite to the target unit is secured to the anchor such that the center of the target unit is offset, out of the way of the anchor, a horizontal distance. 
   One example of the invention provides a golf swing practice system with visual indications of a realistic golf club swinging direction (e.g., straight, slicing, hooking, undercutting, topping, etc.). The golf swing practice system is a compact apparatus that can be deployed indoors and/or outdoors and provides a user the sensation of striking a golf ball with a club. Upon striking a simulated golf ball target, the golf club face is marked with one or more indicators of the position of the golf club face relative to the golf simulated ball target. These one or more indicators can then be used to determine the golf club swinging characteristics, including quality, speed, geometric, and/or direction. 
   Another aspect of the invention provides different ways of marking a golf club face to convey the type of contact between a golf ball and a golf club face. 
   Another feature of the invention provides various types of cartridges that can be used to deposit markings on a golf club face as indicators of the quality and characteristics of a golf practice swing. 
   Yet another feature of the invention provides a reading card that can be used to read or understand the markings on a golf club face. Such reading card may indicate whether the golf club hit the ball straight, sliced, hooked, the relative force or speed of the golf club, etc. 
   Also provided is a computer program and/or online system that instruct users how to read the marking on the golf club and how to correct his/her swing based on these markings. 
   A golf swing practice apparatus is provided including (a) a golf ball simulation target, (b) a supporting member for supporting the target, the support member adapted to anchor the target, the target being movable relative to the supporting member between a normal configuration and an impacted configuration when impacted by a golf club head during a golf practice swing, (c) a connector arm connecting the target to the supporting member, and (d) a marker supported by the target and adapted to mark the face of the golf club head when the face impacts the target during the golf practice swing and with the target in the anchored position. The connector arm may be offset a central line of the target a horizontal distance from a central axis of the support member. The arm may be configured to be raised or lowered relative to the supporting member to adjust the height of the target relative to a support surface. 
   The supporting member may include a stake adapted to allow a user to manually push the stake into the ground and pull the stake out of the ground. 
   The target includes a round member whose outer diameter is approximately the same as the diameter of a golf ball simulated by the target. The target may have a spherical shape approximately the size of a golf ball or a semi-spherical shape approximately the size of half a golf ball. The marker may be a print marker that includes a body containing marking liquid or marking gel. The marker may also include a plurality of print strips that, when the target is impacted by a golf club head, makes one or more marks on the golf club head. The one or more marks indicate the orientation of the golf club head relative to the target and/or the relative force with which the target is struck. The one or more marks may indicate the relative force with which the target is struck. The target is adapted to resiliently spring back after it is impacted by a golf club during the practice swing. 
   Another embodiment provides, a golf swing practice apparatus, comprising: (a) a golf ball simulation target attachable in a golf swing practice position to a support member, (b) a first marker connected to the target to mark a golf club head with a first mark during a golf practice swing on the target, and (c) a second marker connected to the target to mark the golf club head with a second mark during the golf practice swing. 
   The first and second marks may be substantially parallel to one another. The first and second marks can be used to determine whether the golf practice swing was a square, open, or close faced swing at impact of the golf ball simulation target to the golf club head. The first and second marks may also indicate the proximate position where the golf club head would have contacted a real golf ball. When the first mark is longer than the second mark, a close face impact of the golf club head is indicated, and when the first mark is shorter than the second mark, an open face impact of the golf club head is indicated. Different lengths of the first and second marks indicate an open or close face impact by the golf club head and equal lengths of the marks indicate a square hit by the golf club head. The average lengths of the first and second marks indicate the relative speed of the golf club head at impact with the golf ball simulation target. The first and second markers may be print strips formed as part of a replaceable cartridge. 
   Yet another feature provides a golf practice swing marker, comprising: (a) a body of elastic material, and (b) a marking fluid held in the body by wicking or capillary action and adapted to mark a face of a golf club head when the body comes in contact with the golf club head during a golf practice swing. The marking fluid is a marking ink or dye whose mark on the golf club head face is adapted to be wiped off of the golf club head face by a wiping action of a user. The body comprises wicking material, retriculated foam, capillary foam, sponge or retriculated felt. The body is adapted to be coupled to a golf swing practice apparatus. 
   A golf swing practice reader apparatus is also provided comprising: (a) a reading card, (b) a distance and angle indicator, (c) a pin coupled the distance and angle indicator and the reading card, the distance and angle indicator and reader card including markings for reading the amount of hook or slice impact by a golf club from marks on the club head face when the distance and angle indicator is in position relative to the club head face. The distance and angle indicator is in a first position relative to the face when the reading card is reading the amount of hook impact and in a different second position when the reading card is reading the amount of slice impact. The pin may rotate and slide relative to the reading card. The distance and angle indicator may be a windmill indicator. The reading card includes first and second windows and the distance and angle indicator is pivotable and slidable relative to the windows during a reading process. 
   Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the foregoing description taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates an exploded view of a golf swing practice apparatus according to one embodiment of the present invention. 
       FIG. 2  illustrates a perspective view of the golf swing practice apparatus of  FIG. 1 , as it is stalled on a practice mat. 
       FIG. 3  illustrates a perspective view of another version of the invention having a ground stake mounting mechanism. 
       FIGS. 4 and 5  illustrate the right-handed and left-handed mounting positions of a golf ball simulation target, respectively. 
       FIGS. 6 and 7  illustrate how different types of golf clubs may be used with the golf swing practice apparatus. 
       FIG. 8  illustrates an alternative golf ball simulated target coupled to an extension arm having a single marking or printing strip. 
       FIGS. 9 and 10  illustrate how the height of a target can be adjusted (e.g., raised or lowered) as desired. 
       FIGS. 11 and 12  illustrate the operation of a golf swing practice apparatus. 
       FIG. 13  illustrates an alternative golf ball simulated target having a single marking or printing strip after it is struck by a golf club. 
       FIGS. 14 and 15  illustrate a square impact of the golf ball simulated target by the golf club head. 
       FIGS. 16 and 17  illustrate a closed club face (hooked) impact of the golf ball simulated target by a golf club head. 
       FIGS. 18 and 19  illustrate a open club face (sliced) impact of a golf ball simulated target by the golf club head. 
       FIGS. 20-27  illustrate various combinations of markings made using dual print strips of the present invention and their significance is in terms of swing orientation and force. 
       FIG. 28  illustrates an exploded view of a practice target or cartridge assembly according to one implementation. 
       FIGS. 29 ,  30 , and  31  illustrate a back view, a side view and a frontal view, respectively, of the practice target or cartridge assembly, respectively, according to one implementation. 
       FIG. 32  illustrates a cross-sectional view of the assembled practice target or cartridge assembly according to one implementation. 
       FIG. 33  illustrates yet another embodiment of a practice target which has a spherical shape to more closely resemble a real golf ball. 
       FIG. 34  illustrates the typical state of the print strips in a one embodiment of a practice target or cartridge assembly. 
       FIGS. 35 and 36  illustrate how the inertia of the print strips allows them to pop out or extend beyond the surface of the spherical surface of the practice target or cartridge when struck by a golf club head. 
       FIGS. 37 and 38  illustrate a reader card that may be used in conjunction with the golf swing practice apparatus to determine what one or more marks indicate about the quality of the practice swing. 
       FIGS. 39 ,  40 , and  41  illustrate how two marks may be read using the reader card. 
   

   DETAILED DESCRIPTION 
   In the following description, specific details are given to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may not be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. 
   In the following description, certain terminology is used to describe certain features of one or more embodiments of the invention. The term “target” (e.g., golf ball simulation target) refers, but is not limited, to any object or shape intended to be struck by a golf club or serve as an aim for a golf club swing. The terms “print media” and “marker” (e.g., marking cartridge, etc.) refer to anything that holds or includes a marking fluid, gel, or substance and can transfer a mark onto a golf club head. The term “print strip” is one type of print media which has an elongated shape. 
   One example of the invention provides a golf swing practice system with visual indications of a realistic golf club practice swing quality (e.g., straight, slicing, hooking, undercutting, topping, etc.). The golf swing practice system is a compact apparatus that can be deployed indoors and/or outdoors and provides a user the sensation, sound and/or feel, of striking a real golf ball with a club. Upon striking a golf ball simulation target, the golf club face is marked with one or more indicators of the position of the golf club face relative to golf ball simulation target. These one or more indicators can then be used to determine the golf club swing characteristics. 
   Another aspect of the invention provides different ways of marking a golf club face to convey the type of contact between a golf ball simulation target and a golf club face. Such markings made on the golf club face may serve to diagnose various characteristics of the golf swing. 
   Another feature of the invention provides various types of markers that can be used to deposit markings on a golf club face as indicators of a golf swing. 
   Yet another feature of the invention provides a reading card that can be used to read or understand the markings on a golf club face. Such reading card may indicate whether the golf club hit the ball or golf ball simulation target square (straight), open (sliced), and/or closed (hooked) at impact. 
   Also provided is a computer program and/or online system that instruct users how to read the marking on the golf club and how to correct his/her swing based on these markings. 
     FIG. 1  illustrates an exploded view of a golf swing practice apparatus according to one embodiment of the present invention. The golf swing practice apparatus includes an extension arm  102  coupled to a supporting member  104 . The extension arm  102  includes a target base  108  at one end and a mounting coupler  112  at the opposite end of the extension arm  102 . A practice target  114  couples to the target base  108  using fasteners  116 , interlocking tabs, and/or other securing mechanisms. The mounting coupler  112  may define an opening  118  that receives the supporting member  104 . 
   The supporting member  104  includes a shaft or post  120  coupled to a base  122 . When assembled, the post or shaft  120  slides through the opening  118  in the mounting coupler  112  to support the arm  102 . In one embodiment, the shaft  120  may include a plurality of holes  124  which receive a pin  126  to adjust the height at which the practice target  114  is mounted relative to a mounting surface. For example, when inserted into one of the plurality of holes  124 , the pin  126  may support the mounting coupler  112  at a fixed height relative to the support surface. For instance, the bottom edge of the target  114  may be positioned on or adjacent to the practice or support surface to simulate a fairway shot. Alternatively, the bottom edge of target  114  may be spaced a distance, such as one inch, above the support surface to simulate a “teed-up driving” shot. It can also be positioned in between, such as for a “par three” or near support surface shot. The pin  126  may be coupled to the supporting member  104  by a tether  128  so that it is not lost or misplaced when removed from the shaft holes  124 . 
   In some implementations, the mounting coupler  112  may also include an opening through which the pin  126  can pass to reach holes  124  on the shaft or post  120 . In some embodiments, the pin  126  passing through both the mounting coupler  112  and the shaft  120  prevents the mounting coupler  112  from rotating when the practice target  114  is struck. In other implementations, the shaft  120  may have a non-circular cross-section or includes a keyed cross-section that corresponds to the internal contour of the opening  118  thereby preventing the mounting coupler  112  from rotating while adjusting the height of  102  or when the practice target  114  is struck. 
   The base  122  may include an attaching/detaching mechanism that permits the golf swing practice apparatus to be mounted on different supporting surfaces. For example, a golf practice mat  130  may serve as the supporting surface for the golf swing practice apparatus. A mounting base  106  positioned on one side of the mat  130  is coupled to a backing plate  132  on the opposite side of the mat  130  by a fastener  134  and retaining nut  136 . Other mounting or retaining mechanisms may also be employed without departing from the invention. The base  122  can then be coupled to the mounting base  106 . This mechanism permits setting the practice target  114  at the surface of the practice mat  130  or below or above the top of the practice grass  138 . 
     FIG. 2  illustrates a perspective view of the golf swing practice apparatus of  FIG. 1 , with the assembled extension arm  102  and supporting member  104 , separated from the mounting base  106  on a practice mat  202 . Since the various parts of the golf swing practice apparatus, including the target  114 , base  108 , arm  102 , coupler  112 , shaft/post  120 , pin  126 , base  122 , and/or backing plate  132 , may be intentionally or accidentally struck by a golf club (e.g., when a golfer misses the target and hits a different part of the golf swing practice apparatus), these parts may be constructed from sufficiently strong and/or flexible materials capable of withstanding such forces. For instance, the shaft  120  may be made from an elastic material that allows the shaft  120  to flex if struck directly by a golf practice swing. This increases the durability and/or life of the golf swing practice apparatus. 
     FIG. 3  illustrates a perspective view of another version of the invention having a ground stake mounting mechanism. The arm  102  and supporting member  104  for the golf swing practice apparatus of  FIG. 1  are illustrated in an assembled state. However, in this illustration a ground stake  302  is used as the mounting mechanism. That is, the base  122  couples to a mounting base  304  of the ground stake  302  to provide support to the golf swing practice apparatus. The ground stake  302  may include one or more fins  306  extending from a center pin  308 . A player can simply press the ground stake  302  into the ground and then couple the base  122  to the mounting base  304 . The base  122  may include guides that couple, snap, and/or slide into matching rails on the mounting base  304  to secure the supporting member to the ground stake  302 . So that the golf swing practice apparatus may withstand the significant forces of a practice golf swing when any part of the apparatus is struck, one embodiment provides for the base  122  to be detachable from the mounting base if sufficient force is applied (e.g., a golf practice swing accidentally strikes the shaft  120  directly). This prevents the ground stake  302  and/or other parts of the golf swing practice apparatus from breaking under the significant forces generated by a golf practice swing. 
     FIGS. 4 and 5  illustrate the right-handed and left-handed mounting positions of a golf ball simulation target  114 , respectively. That is,  FIG. 4  illustrates how the practice target  114  is positioned on a first face of the target base  108  for right-handed golf club swinging. The practice target  114  maybe detached from the first face of the target base  108  and coupled to the opposite face of the target base  108  to accommodate a left-handed golf swing. 
     FIGS. 6 and 7  illustrate how different types of golf clubs may be used with the golf swing practice apparatus.  FIG. 6  illustrates how a four iron golf club may be used to practice on the golf swing practice apparatus. Similarly,  FIG. 7  illustrates the use of a driver golf club to practice on the golf swing practice apparatus. It should be noted that the arm  102  may be lowered or raised relative to the playing mat  202  or supporting surface according to the desired practice height of the target  114 . For instance,  FIG. 6  illustrates how the target  114  is placed at the level of the simulated playing turf  604  for practicing with the four iron golf club  602 . In another example,  FIG. 7  illustrates how the arm  102  is raised to place the target  114  at a height similar to a tee for practicing with the driver golf club  702 . 
     FIG. 8  illustrates an alternative golf ball simulated target  802  coupled to an extension arm  804  having a single marking or printing strip  806 . Such single marking strip  806  maybe used to ascertain the relative force with which a golf club strikes the practice target  804  as well as the position at which the golf club head contacts the practice target  804 . In other embodiments, rather than using one or more vertical marking strips, the marking strips may have a horizontal or diagonal, or a combination of horizontal, diagonal, and/or vertical marking strips. Additionally, rather than using strip shapes, the marking element(s) may have other shapes, including one or more dots, squares, triangles, circles, etc. 
     FIGS. 9 and 10  illustrate how the height of a target can be adjusted (e.g., raised or lowered) as desired. That is,  FIG. 9  illustrates how the practice target  802  may be placed at a first height (e.g., to simulate a golf ball placed on a tee).  FIG. 10  illustrates how the practice target  802  may be lowered to the level of the grass  808  on practice mat  810  (e.g., to simulate hitting the golf ball on the playing surface or fairway). This height adjustment may be performed by sliding the extension arm  804  up or down on the supporting post  912  and securing it at the desired height. 
     FIGS. 11 and 12  illustrate the operation of a golf swing practice apparatus.  FIG. 11  illustrates a golf swing practice apparatus  1102  prior to the practice target  1104  being struck by the face of a golf club  1106 .  FIG. 12  illustrates the golf swing practice apparatus  1102  after the practice target  1104  has been struck by the face of a golf club  1106 . The arm  1108  flexes backwards when struck and the print strips  1212  on the practice target  1004  leave print marks  1210  on the face of the golf club  1106 . The arm  1108  may flex back into its original position after the golf club  1106  passes. In other implementations, the arm  1108  may rotate completely or partially about its supporting post instead of or in addition to flexing. 
   In yet other embodiments, a different supporting mechanism may be employed. For example, the practice target may be tethered or supported by a vertical arm, rather than the horizontal extension arm  1108  illustrated in  FIGS. 11 and 12 . When struck by a golf club, the target travels in a vertical trajectory instead of a horizontal trajectory. 
     FIG. 13  illustrates an alternative golf ball simulated target having a single marking or printing strip after it is struck by a golf club. The single marking strip  1302  makes a mark  1304  at the point at which it contacts the golf club head  1306 , thereby simulating where the golf club would contact a real ball. The length and/or width of the mark  1304  may be indicative of the force with which the target  1308  is struck. Additionally, this mark provides an indication of where the target  1308  was struck relative to a sweet spot of the golf club head. 
     FIGS. 14 and 15  illustrate a square face (straight) impact of the golf ball simulated target  1402  by the golf club head  1404 . In a square face impact, the angle A between the golf club head and the arm or tangent line at the point of impact is zero. As noted in  FIG. 15 , two marks  1506  are made by the marking strips  1408  near the center of the sweet spot  1510  for the golf club head  1404 . Because these marks  1506  are approximately the same size, this indicates a substantially straight or square impact and translates to a straight direction for the trajectory of a real golf ball. 
     FIGS. 16 and 17  illustrate a closed face (hooked) impact of the golf ball simulated target  1602  by a golf club head  1604 . In a close face impact, the angle B between the golf club head and the arm or tangent line at the point of impact is greater than zero. As noted in  FIG. 17 , two marks  1706  and  1712  are made by the marking strips  1608  offset from the sweet spot  1710  of the golf club head  1604 . Because these marks  1706  and  1712  are different sizes and the outer mark  1706  is longer than the inner mark  1712 , this indicates a close club face (hooked) swing at an offset impact point. 
     FIGS. 18 and 19  illustrate an open club face (sliced) impact of a golf ball simulated target  1802  by the golf club head  1804 . In an open face impact, the angle C between the golf club head and the arm or tangent line at the point of impact is greater than zero. As noted in  FIG. 19 , two marks  1906  and  1912  are made by the marking strips  1808  offset from the sweet spot  1910  of the golf club head  1804 . Because these marks  1906  and  1912  are different sizes and the inner mark  1912  is longer than the outer mark  1906 , this indicates an open club face (sliced) swing at an offset impact point. 
     FIGS. 20-27  illustrate various combinations of markings made using dual print strips of the present invention and their significance is in terms of swing orientation and force.  FIGS. 20 and 21  illustrate marks on the face of a golf club indicating a light and heavy straight and square impact, respectively, positioned relative to a sweet spot  2004 . That is, the shorter marks  2002  on  FIG. 20  indicated a lighter impact than the longer marks  2102  on  FIG. 21 .  FIGS. 22 and 23  illustrate marks on the face of a golf club indicating a hard hook with a light and heavy impact, respectively. That is, in  FIG. 22  the longer mark  2202  toward the outer edge of the golf club head relative to the shorter mark  2204  toward the inner edge of the golf club head indicates a hard hook with a light impact in the center of the sweet spot  2206  of the golf club head. In  FIG. 23 , the longer mark  2302  toward the outer edge of the golf club head relative to the shorter mark  2304  toward the inner edge of the golf club head indicates a hard hook with a heavy impact on the edge of the sweet spot  2306  of the golf club head. In contrast,  FIGS. 24 and 25  illustrate marks on the face of a golf club indicating, respectively, an open face (sliced) shot positioned offset from sweet spot  2406  and an open faced (sliced) shot within sweet spot  2506 . That is, in  FIG. 24  the longer mark  2404 , toward the inner edge of the golf club head, relative to the shorter mark  2402 , toward the outer edge of the golf club head, indicates a hard slice with heavy impact near the inner edge of the sweet spot  2406 . In  FIG. 25  the longer inner mark  2504  and shorter outer mark  2502  indicate a hard slice at the center of the sweet spot  2506 . That is, the difference between the lengths of the two marks can be used to determine whether a swing is a hard or light close face (hook) or open face (slice) swing. Meanwhile, the average length of the two marks can be used to determine the relative club head speed during a close face (hook) or open face (slice) swing.  FIG. 26  illustrates two partial marks  2602  near the bottom edge of the golf club head which is indicative of a golf ball being topped (i.e., golf club head contacted the golf ball or target too high). In  FIG. 27 , the angled marks  2702  may indicate that the player is standing too far from the ball or that the golf club is too long. That is, a lie angle D formed between the longitudinal axis of the marks  2702  and vertical alignment lines  2704  (e.g., ball grip grooves) on the face of the golf club head can be used to diagnose various conditions. For instance, if the angle D is approximately ninety degrees, this indicates a proper golf club length and swing stance distance. On the other hand, if the angle D is less than ninety degrees, this indicates that the golf club is too long or that the player is standing too far from the ball/target. According to one feature of the invention, one or more of the printing strips may have different color ink and/or shapes so that the markings on a golf club face can be easily distinguished by their different colors. In one implementation, the ink may be selected so that it evaporates after an amount of time after the swing (e.g., 30 seconds, 1 minute, etc.) thereby avoiding the need to swipe the surface clean prior to taking another swing. 
   Since the practice target  114  ( FIG. 1 ) is tethered, a golfer can get real-life practice swings and feedback information on the swing without the necessity of using a real golf ball that must take flight to show the effects of a swing. Even a real golf ball will not indicate the quality of the swing to the degree of the present invention since golf balls do not print a mark on the club face that provide information about a swing. The footprint of a mark indicates the quality of the swing thereby providing realism without large space requirements. 
     FIG. 28  illustrates an exploded view of a practice target or cartridge assembly  2800  according to one implementation. The cartridge assembly  2800  may have a spherical or semispherical shape to resemble the size, look and feel of a real golf ball. In this embodiment, two print strips  2802  are securely held in place within a cartridge assembly  2800  formed by a cover  2804  and a rear plate  2806 . The print strips  2802  may be straight but bend or adapt to a curved form when inserted in the cartridge assembly  2800 . The print strips  2802  are located on or near the surface of the practice target  2800  through openings  2808  in the cover  2804 . The rear plate  2806  may be shaped to press substantially evenly on the print strips  2802 . The cartridge assembly  2800  is formed by the rear plate  2806  and cover  2804  coupled together with the print strips  2802  securely housed therein. The cover  2804  may be made of a sufficiently tough and/or resilient material to withstand being struck by a golf club. 
     FIGS. 29 ,  30 , and  31  illustrate a back view, a side view and a frontal view, respectively, of the cartridge assembly  2800  according to one implementation.  FIG. 29  illustrates a back view of the cartridge assembly having symmetric openings  2902  and  2904  through which fastening screws  2810  can pass to secure the rear plate  2806  to print strips  2802  and the cover  2804  together.  FIG. 30  illustrates how the print strips  2802  extend vertically over a significant portion  3004  of the face of the cover  2804 . By extending over such vertical arcuate length  3004 , the print strips  2802  are able to make contact with different types of golf clubs that may strike the practice target or cartridge assembly  2800  at different points or angles. The length  3004  of the print strips  2802 , extending from near the bottom point of the target  2800  to above the mid-point of the target  2800 , insures that impact marks made on the golf club head represent a substantially realistic region at which the golf club head would have impacted a real golf ball. In reality, a golf club head would impact a real golf ball in between these two marks. The practice target or cartridge assembly  2800  is similar in shape, hardness, and mass of a real golf ball to provide a realistic sensation (e.g., impact, feel, and/or sound) during a practice swing. In alternative implementations, one or more print strips may be positioned horizontally, vertically, diagonally or a combination thereof. Additionally, instead of strips, the marking element may have different shapes, such as round, square, triangular, etc., and/or different lengths or sizes. 
   The print strips  2802 , holding the printing or marking fluid, are resilient and thus are affected by the acceleration during impact. To prevent the print strips  2802  from popping out when the practice target or cartridge assembly is struck by a golf club, various securing mechanisms may be employed. For example,  FIG. 32  illustrates a cross-sectional view of the assembled practice target  2800  according to one implementation. The rear plate  2806  tightly presses the print strips  2802  against the inner surface of the cover  2804 , with the tips of the print strips  2802  positioned within openings  2808  in the cover  2804 . To secure the print strips  2802  within the practice target  2800 , the print strips  2802  include grooved winged edges  3202  that interlock with corresponding retaining grooves  3204  on the inner surface of the cover  2804 , adjacent the interior longitudinal edges of the openings  2808 . 
   Because the target or cartridge assembly  2800  will be exposed to significant forces when struck by a practice golf swing, it is designed to absorb and withstand these forces while safeguarding the print strips  2802  and providing the feel or sensation of a real golf ball when struck by a practice golf swing. For this purpose, one embodiment of the rear plate  2806  and cover  2804  are configured to absorb the impact of a practice golf swing. In particular, the cover  2804  includes a primary impact region  2818  between the openings  2808 . The interior of the impact region  2818  is in direct contact with an impact absorption region  2816  in the rear plate  2806  so that the force of a practice golf swing is transferred to the rear plate  2806 . The interior rear plate  2806  is curved to provide curvature to the print strips  2802 . The interior of the rear plate  2806  may also include recessed zones or grooves  2812  to receive the print strips  2802 . A plurality of support posts  2814  creates a space between the recessed zones  2812  and print strips  2802 . This space allows the print strips  2802  to move into the recessed grooves  2812  when the target  2800  is struck with sufficient force to cause the cover retaining grooves  3204  to press on the grooved winged edges  3202 . Allowing the print strips  2802  to move into the recessed grooves  2812  prevents them from being cut or damaged by the cover retaining grooves  3204  when the target  2800  is struck by a golf club. When the target  2800  is struck, the retaining grooves  3204  press on the winged edges  3202  causing them to bend into the recessed grooves  2812 . 
   One problem that may be encountered when the target  2800  is struck with exceptional force by a golf club is that the impact region  2818  and/or impact absorption region  2816  may compress sufficiently that the golf club head also contacts the outer edges of the cover openings for the print strips. If this occurs, the sides of these openings would squeeze and/or deform the print strips  2802 . To avoid this problem, one embodiment of the invention provides openings  2808  having rounded outer edges  3102 . By rounding the outer edges  3102  as shown, the golf club head is less likely to come into contact with these outer edges  3102 , thereby avoiding damage, squeezing, and/or deformation to the print strips  2802 . 
     FIG. 33  illustrates yet another embodiment of a practice target  3302  which has a spherical shape to more closely resemble a real golf ball. This spherical target  3302  may be created, for example by adding a semi-spherical rear cover  3304  to the semi-spherical target  114  illustrated in  FIG. 1 . In an alternative embodiment, the target  3302  may be a free-flying golf ball having printing markers  3306  that operate to mark the golf club face as previously described. 
     FIGS. 34 ,  35 , and  36  illustrate various exemplary states of the print strips in a one embodiment of a practice target.  FIG. 34  illustrates how the print strips  3402  are submerged below the outer surface (e.g., 0.024 inches) of the practice target  3404  before impact. That is, the print strips  3402  are positioned near the surface of the practice target  3404 . The amount by which the print strips  3402  are submerged depends on various factors including the shape of the practice target, the compression of the practice target, flexing of the print strips  3402 , among other design factors. 
     FIGS. 35 and 36  illustrate how the inertia of the print strips  3402  allows them to pop out or extend beyond the spherical surface of the practice target  3404  when the practice target  3404  is struck by a golf club. Because the print strips  3402  extend out more or less depending on the force with which the practice target  3404  is struck, the marks made on the golf club head provide an indication the relative speed of the club head during impact. That is, a different mark footprint (width and/or length) is made by the print strips  3402  on the golf club head depending on the speed and angle of the golf club face. For example, when a golf club face is angled in a close face (hook) or open face (slice) orientation relative to the practice target  3402  during impact, the separation of the print strips  3402  assures that the lengths of the print marks will be different because one print strip or the other will be closer to the direct tangent point of impact on the golf club face. When the club face impacts the practice target  3404  with a square hit, both print marks made by print strips  3402  will be approximately of equal length. The present invention has been described above as including a marker which prints or otherwise deposits a small nonpermanent mark on the face of the golf club corresponding to the impact location of a golf ball simulated by the target during the practice swing. An alternative embodiment of the invention, instead of depositing a mark on the face, deposits an impact mark either on an impact sticker on the face of the golf club head or on a spray coating on the face. The stickers are known in the art as shown by U.S. Pat. No. 5,142,309 (Lee) and by many commercially available “impact marking decals,” such as the CADDYPATCH Suede Leather Ball Impact Marker and the LONGSHOT Impact Labels; and the spray can be the On-Mark Impact spray “Game Improvement in a Can.” 
   In yet another implementation, instead of the marker depositing a print spot on the face of the golf club head, a further embodiment of the invention makes a scuff mark. To make the scuff mark, the marker would not include marking fluid. Rather, the marker would be formed of a material such as hard rubber which leaves a scuff mark when it impacts a golf club head face. 
     FIGS. 37 and 38  illustrate a reader card that may be used in conjunction with the golf swing practice apparatus to determine what a mark indicates. For example, the amount of the hooking or slicing action can be measured with this novel tool.  FIG. 37  illustrates a front view of this reader card  3700  while  FIG. 38  illustrates a back view. A “windmill-shaped member”  3710  is pivotally coupled at its center location by a pin or rivet  3712  to the card  3700  of the device and the pin or rivet can slide in the slot  3714  in the reader card  3700  for adjustment and reading purposes. The card  3700  has two windows  3702  and  3704 . 
   The reader card  3700  is oriented and positioned for either hook or slice conditions. The windmill  3710  is slid via its pin or rivet  3712  in the slot  3714  and rotated to align it. The card is then read, by noting which of the bands—the first  3716  (which indicates a light hit—a tap), the second  3718  (which indicates a medium hit) and the third  3720  (which indicates a hard hit). The bands  3716 ,  3718 , and  3720  can be differently colored, and more than three bands can be provided or even just two. The position of the windmill  3710  also indicates the amount of hook or slice. For example, the location of the slice arrow  3722  relative to bands  3726 ,  3728 , and  3730  indicate the amount of slice. Similarly, the location of hook arrow  3724  relative to bands  3732 ,  3734 , and  3736  indicates the amount of hook. 
     FIGS. 39 ,  40 , and  41  illustrate how two marks may be read using the reader card  3700 . To determine whether a particular set of marks indicate a square (straight), open face (hook), or close face (slice) impact, the marks are aligned against a first edge of the reader cared opening  3702  or  3704  while the opposite ends of the marks are aligned against an edge of the windmill  3710 . At this moment, the arrows  3722  and  3724  would indicate the distance and amount of hook or slice. 
     FIG. 39  illustrates two equal-length marks  3902  and  3904  on the face of a golf club head  3906 . In this example, arrow  3722  indicates that the two marks  3902  and  3904  are straight (i.e., a square impact, no slice or hook) by pointing to the no slice (square) band  3730 . Meanwhile, arrow  3724  indicates that this was a relatively long distance  3736 .  FIG. 40  illustrates an exterior long mark  4002  and an interior short mark  4004 , indicating a hook where the distance is indicated by arrow  3722  pointing to distance  3718  and the amount of hook is indicated by arrow  3724  pointing to band  3734 .  FIG. 41  illustrates an exterior short mark  4102  and an interior long mark  4104 , indicating a slice where the distance is indicated by arrow  3724  pointing to distance  3718  and the amount of slice is indicated by arrow  3722  pointing to band  3728 . 
   Yet another aspect of the invention provides a software application or website that a user can access to learn more about his/her swing based on the markings on the golf club face. The software application or website may provide animated instruction on how to correct different swing problems based on the markings on the club face. 
   Another aspect of the invention may provide additional features built into the golf swing practice system. Various sensors may be mounted on the target or the apparatus that measure velocity, force, and/or acceleration. For instance, a force sensor on the target may indicate the force with which the target is struck and display it on a display screen on the apparatus. Additionally, the measured force may be converted to an equivalent distance that a golf ball would have traveled. This equivalent distance may be provided to the golfer via said display. Alternatively, velocity or acceleration sensors may be mounted at or near the apparatus that indicates the velocity and/or acceleration of the golf club head before it strikes the target or the velocity and/or acceleration of the target after being struck by the golf club head. Such velocity and/or acceleration information may then be converted into an equivalent distance that a golf ball would have traveled and is provided to the golfer. Such sensors may be controlled by a small processor coupled to the apparatus. Additionally, a communication port may be provided as part of the apparatus that permits coupling the apparatus to a computer to record or download information from the apparatus and/or its sensors. 
   From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention which come within the province of those skilled in the art. The scope of the invention includes any combination of the elements from the different species or embodiments disclosed herein, as well as subassemblies, assemblies, and methods thereof. As examples only, the various target and ground or mat anchors can be interchanged as can the print, scuff or impact arrangements, as well as the materials and dimensions. All such variations not departing from the spirit of the invention are considered as within the scope thereof. 
   It should be noted that the foregoing embodiments are merely examples and are not to be construed as limiting the invention. The description of the embodiments is intended to be illustrative, and not to limit the scope of the claims.