Abstract:
Device for practicing a sequence of movement in the golf swing, includes a base, and a first support, that is mounted on the base in a manner such that it can pivot about a first vertical axis and is intended for a golf player to place a first foot onto the first support which has a first supporting part for supporting the front part of the foot and a second supporting part that can be pivoted about a horizontal axis and is intended for supporting the heel of the first foot, a guide device is provided which is arranged on the base in a manner such that it at least partially surrounds the first vertical axis and which exhibits a curved design which rises from a lowermost point and which supports the second supporting part, and a second support is provided for the golf player to place his second foot on.

Description:
The present invention relates to a device for practicing a sequence of movement in the golf swing. 
     It is normal practice that a golfer practicing a golf swing, especially the tee-off, will be observed, judged and instructed by a golf trainer. However, when the golfer practices all for himself, faults may occur in the sequence of movement without the golfer getting aware of them. The golfer gets used to the faulty sequence of movement and will have difficulty later to cure the mistake. 
     The present invention has for its object to provide the golfer with a means that will help habituating him to a better sequence of movement in practicing the golf swing. 
     SUMMARY OF THE INVENTION 
     That object is achieved by a device having the features defined in Claim  1 . Advantageous further developments of the invention are the subject-matter of the subclaims. The device according to the invention for practicing the golf swing comprises a base and two supports mounted on the base and intended for the golf player to place his feet on. A first support intended for a first foot of a golfer is mounted on the base in a manner such that it can pivot about a first vertical axis. The first support has a first supporting part for supporting the front part of the foot and a second supporting part for supporting the heel of the first foot. The second supporting part can be pivoted about a horizontal axis, being guided and supported by a guide device which is arranged on the base in a manner such that it at least partially surrounds the first vertical axis. The guide device has a curved design, surrounding the first vertical axis, and rises from a lowermost point. Further, the device according to the invention comprises a second support which is intended for the golf player to place his second foot on. While the second support may consist of the base as such, or may be part of the base, it preferably is a part separate from the base. 
     For practicing the sequence of movement for the tee-off, the golfer places his feet on the two supports and either simulates a tee-off without a golf club or practices the tee-off with a golf ball. In doing so, he is expected to swing the one of his hips, that points away from the target of the ball, in the direction of that target. Connected with this movement is a rotation of his foot, which points away from the target, which rotation is facilitated and supported by the support mounted on the base. The pivoting movement of the first support simultaneously lifts the second supporting part of the support, supporting the heel of the foot that points away from the target, as the second supporting part moves along the guide device, the latter being designed to rise from a lowermost point. The arrangement of the device is selected so that the second supporting part is supported on the lowermost point of the guide device when the golfer is in its starting or initial position from which he starts the golf swing. In that starting or initial position, the two supporting parts should have substantially the same height. During the follow-through movement, the second supporting part, being guided by the guide device, necessarily raises the heel placed on it. 
     This provides substantial advantages:
         The device supports the golfer in arriving at a sequence of movement that is favorable for a tee-off.   The pivoting first support makes it easier for the golfer to turn his hip, which points away from the target, toward the target during the follow-through movement.   The second supporting part, which rises during the pivoting movement of the first support, necessarily raises the heel of the foot resting on it.   The design of the guide device can be suitably configured to predefine an ergonomically favorable sequence of movement, from the foot to the hip of the leg that points away from the target.   The sequence of movement for the leg that points away from the target, being predefined by the contour of the guide device and remaining always the same, helps the golfer to habituate himself to an invariable sequence of movement which makes the golfer&#39;s playing strength more stable.   The device is suited for both simulated tee-offs practiced with or without a golf club, and also for tee-offs practiced with a ball. Especially, it allows the golfer to practice and improve the rotary push-off by the foot that faces away of the target, which is to accompany the follow-through movement and which is so important for an accurate and long tee-off.   The device trains and builds up the muscles that participate in the tee-off and, especially, in the rotary push-off.   The device is suited for use on the driving range of a golf court and also as a practicing device in sports studios, hotel fitness rooms and for use in the golfer&#39;s own home.       

     The second support, on which the golfer is to place his second foot, i.e. the one facing the target, is mounted on the base in a manner such that, preferably, it can pivot about a vertical axis. This helps relieve and spare the joints and ligaments of a golfer in practicing and furthers a smooth easy-going sequence of movement. 
     Preferably, the two supports have a mechanically defined initial position to which they will return preferably automatically after having been swung out of their initial position. In their initial position, the two supports should be arranged in a way corresponding to the golfer&#39;s natural training position. In the natural standing position, the feet normally enclose between them an angle of between 0° and 30°. The same is preferred for the initial position of the two supports. 
     For returning the supports to their initial positions, each support preferably coacts with a spring which is tensioned when the support is swung out of its initial position so that its tension tends to pull the support back to its initial position. The force required for tensioning the spring must be applied by the practicing golfer, and this further contributes to improving the training success and the buildup of the muscles. 
     The first axis, about which the first support can be pivoted, preferably is arranged below the first supporting part of the first support. This is favorable under ergonomic aspects. 
     For ensuring the pivotable mounting and support of the first support, there is preferably provided an arrangement consisting of a hollow or a solid pin and a sleeve in which the pin is received. The arrangement is such that either the pin is mounted on the base and the sleeve is mounted on the bottom of the first support, especially on the bottom of the first supporting part of the first support, or the sleeve is mounted on the base and the pin is mounted on the bottom of the first support. The pin and the sleeve engage each other thereby rendering possible not only the desired pivoting movement but also transmission of the golfer&#39;s weight to the base of the device. 
     A momentum tending to return the first support to its initial position can be produced, for example, by arranging between the support and the base, or between the sleeve and the pin, a torsion spring that will be tensioned when the support is swung out of its initial position. Another, especially advantageous possibility consists in providing a slotted link in the pin which is engaged by a bolt arranged in the sleeve, or by providing a slotted link in the sleeve which is engaged by a bolt provided on the pin. The slotted link is given a slope such that the first supporting part of the first support will move in downward direction when being pivoted out of its initial position. The pin then moves downward in the sleeve. When a helical spring is provided in the sleeve, which is engaged and compressed by the pin as it moves down in the sleeve, then the helical spring will be compressed when the first support is pivoted out of its initial position. The restoring force building up during that movement is capable of restoring the support to its initial position when the golfer yields to the restoring force, at the end of the golf swing. 
     This further development of the invention can be realized with particular advantage when the pin is designed as a hollow pin whose inner space can be used for accommodating the helical spring so that a longer helical spring with longer spring excursion can be used. Another advantage of that embodiment of the invention lies in the fact that the first supporting part is moved down, against the restoring force of the helical spring, as the first support is pivoted out of its initial position. This contributes toward raising the second supporting part relative to the first supporting part so that the raising task does not have to be performed by the guide device alone. At the same time, the rotary push-off, which is to accompany the follow-through movement and which is effected by the golfer by that foot which points away from the target, is suited to reinforce, or even to initiate, the desired rotary movement of the golfer&#39;s body as a result of the downwardly acting push-off force of the foot. This again furthers the raising movement of the second supporting part of the pivotable first support. The slotted link that combines the pivoting movement of the first support and its downward movement during the rotary push-off is of particular importance for the training success gained with the aid of the device. 
     When the golfer pushes himself off during the follow-through movement using that foot which points away from the target, then he does this using the front of his foot. Accordingly, it is an advantage if the pin and the sleeve, which allow the first support to rotate, are arranged below the first supporting part, which supports the front of the golfer&#39;s foot, so that the push-off force is transferred as directly as possible to the arrangement consisting of the slotted link and the bolt by which it is engaged, in order to initiate and/or reinforce the rotary movement. 
     The slope of the slotted link preferably is between 0.01 cm per degree up to 0.025 cm per degree of the pivot angle, especially approximately 0.02 cm per degree of the pivot angle of the first support. This provides for a lowering movement of the first supporting part by up to 2 cm in the course of a golf swing. 
     The spring, which opposes resistance to the downward movement of the pin into the sleeve, may also be arranged on the outside, in which case it surrounds the pin and is engaged by the forward end of the sleeve. When the sleeve is mounted on the bottom of the first support, then the spring is compressed between the sleeve and the base of the device. When the sleeve is mounted on the base, then the spring is compressed between the sleeve and the bottom of the first supporting part of the first support. An inner spring is, however, preferred over an outer spring. 
     The inner spring need not necessarily be a helical spring; instead of a helical spring, a stack of cup springs may be provided as well. 
     Preferably, the first support coacts with two slotted links with oppositely directed slopes, and the bolt engages either the one slotted link or the other slotted link. This provides the advantage that the swinging direction of the support can be varied. And this is necessary when one and the same device is to be used by right-handed and by left-handed individuals. 
     Preferably, a spring—the second spring—is provided also for the second support; that spring tends to return the second support to its initial position after it has been swung out of its initial position. The second spring preferably is a torsion spring that surrounds the second axis about which the second support can be pivoted. However, the second spring may also be a helical spring, arranged in the same way as the helical spring which is preferred for the first support. 
     For pivotally mounting the second support on the base there is provided, just as in the case of the first support, an arrangement consisting of a solid or a hollow pin and a sleeve adapted to receive the pin. Again, a slotted link is provided either in the pin or in the sleeve, for being engaged by a bolt provided in the sleeve or in the pin. The slotted link defines a defined position of the second support and limits its pivoting movement. While the slotted link associated with the first support is to allow a pivot angle of 90° for swinging the support out of its initial position, the pivoting angle of the second support, allowed by the second slotted link, preferably is much smaller and, preferably, not over 30°. The slotted link for the second support may be horizontal, or may be given a slope so that the second support is pushed down a little as it is swung out of its initial position. This provides the advantage that the restoring force of the second spring, coacting with the second support, can be gained not only from torsion but also from compression of a helical spring and that the foot placed on the second support is permitted to follow the downward movement of the front part of the foot over a certain distance in the course of the golf swing. 
     The slope of the second slotted link, coacting with the second support, preferably is 0.005 cm per degree, up to 0.015 cm per degree, especially 0.01 cm per degree of the pivot angle of the second support. 
     The base of the device preferably is provided with holders for the two supports that are arranged at different spacings. This provides the advantage that the spacing of the supports can be adapted to different persons with their respective natural standing positions. Preferably, the holders are bores adapted to receive the pin, for example, about which the respective support can be pivoted. To vary the spacing of the supports it is then only necessary to change the bore for one of the supports, preferably the second support. 
     Preferably, the base of the device is provided with holders also for the guide device. The holders for the guide device and for the two supports preferably are designed and arranged so that the position of the two supports and the guide device can be changed, from a given arrangement to a mirrored arrangement. This is advantageous to make one and the same device suited for use by right-handed and also by left-handed persons. 
     The base of the device preferably is a horizontal plate on which the two supports and the guide device for the first support are mounted. To save weight, the plate may be provided with recesses. 
     The first supporting part and the second supporting part of the first support may be connected one with the other. Preferably, the second supporting part is hinged directly to the second supporting part. This is the simplest way of procuring that, for raising the heel, the first supporting part can be pivoted in upward direction from a horizontal initial position, in which it is in alignment with the first supporting part. 
     A roller provided on the first support, preferably on its second supporting part, is adapted to roll on the guide device. This ensures a low-friction guiding effect. 
     In order to permit tee-offs to be not only simulated, but also effectively carried out on the device, the device preferably is provided with a tee-off surface on which the golf ball can be placed in a suitable tee-off position. Alternatively, or additionally, the device may also be provided with a positioning tee on which the golf ball can be placed in a suitable tee-off position. The tee used need not necessarily be a rigid tee, but may also be a flexible tee, for example one equipped with an upright piece of an elastomeric tube of the kind normally used on tee mats on the driving range. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the invention are illustrated diagrammatically in the attached drawings. 
         FIG. 1  shows an oblique view of a device according to the invention, with both supports in their initial position; 
         FIG. 2  shows a first oblique view of the device, with both supports pivoted out of their initial positions; 
         FIG. 3  shows a second oblique view of the device, with both supports pivoted out of their initial positions; 
         FIG. 4  shows an oblique view of the second support, as a detail, in its initial position; 
         FIG. 5  shows an oblique view of a second support, similar to  FIG. 4 , but pivoted out of its initial position; 
         FIG. 6  shows an side view of the first support as a detail, in its initial position; 
         FIG. 7  shows an oblique view of the first support in its initial position; 
         FIG. 8  shows a side view of the first support, similar to  FIG. 6 , but in a position swing out of its initial position; 
         FIG. 9  shows an oblique view of the first support, similar to  FIG. 7 , but in a position swung out of its initial position; 
         FIG. 10  shows an oblique view of the first support, swung out of its initial position, but viewed from a direction different from that of  FIG. 9 ; 
         FIG. 11  shows an oblique view of the guide device as a detail, placed on a mounting plate; 
         FIG. 12  shows a view similar to  FIG. 11  of the guide device, supplemented by hollow pin, placed on the mounting plate; 
         FIG. 13  shows a detail view, taken obliquely from below of a first supporting part of the first support, with a sleeve mounted on the bottom for receiving the hollow pin from  FIG. 12 ; 
         FIG. 14  shows an oblique detail view of the sleeve of  FIG. 13  in combination with a helical spring and two plug-in bolts; 
         FIG. 15  shows a side view of the sleeve from  FIG. 14 ; 
         FIG. 16  shows an oblique view of the base of the device; 
         FIG. 17  shows a variation of the device in a representation similar to that of  FIG. 4 ; and 
         FIG. 18  shows a variation of the device in a representation similar to that of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an overall view of the device. It has a base  1  consisting of a flat plate with two separate bores  2 , two rows of five bores  3  each, four separate pins  4  and four rows of five pins  5  each, provided in mirrored arrangement—see  FIG. 16 . The pins  4  and  5  are either solid and have an external thread, or are hollow in which case they have an internal thread. 
     A first support  6  is mounted on a first footplate  7  provided with two bores as passages for two pins  4  and five bores as passages for a row of five pins  5 . A screw cap  8  is screwed onto each of the two pins  4  and the pins  5 , for fixing the first footplate  7  on the base  1 . 
     Above the bore  2  of the base  1 , a sleeve  9  receiving a first—hollow—pin  10  is fixed on the first footplate  7 . The pin  10  is mounted on the bottom of the first support  6 , on a first supporting part  11  to which a second supporting part  12  is linked in a manner such that it can pivot about a horizontal axis  13 . 
     The interaction of the first sleeve  9  and the first pin  10  will become clear from  FIGS. 6 and 12  to  15 : The first pin  10  comprises two slotted links  14  that extend approximately a quarter circle around the first pin  10 , with oppositely directed slopes. The first sleeve  9  has two radial threaded bores  15  with a locking element  34  screwed into each bore, the latter being provided for that purpose with a base portion  35  with an external thread that can be screwed into the threaded bore  15 . A bolt  17  seated in the base portion  35  projects from the base portion  35  in forward direction and can be withdrawn into the base portion  35  by a handle  16 , against the action of a spring, and can be fixed in that retracted position by rotation of the handle  16 . When the first pin  10  is introduced into the first sleeve  9 , the bolt  17  can be advanced only when one of the two slotted links  14  is in alignment with the respective threaded bore  15 . 
     The position of the two radial threaded bores  15  is adjusted to the position of the two slotted links  14  so that in one particular position—namely the initial position of the first support  6 —each of the two slotted links  14  can be simultaneously engaged by a bolt  17 . That position is shown in  FIGS. 6 and 7 . Due to the oppositely directed slope of the two slotted links  14 , pivoting of the first support  6  is then not possible; the first support  6  is locked in its initial position. To allow the support to be pivoted, one of the two bolts  17  illustrated in  FIGS. 6 and 7  must be withdrawn using the handle  16 . Which one of the bolts  17  is to be withdrawn depends on whether the first support  6  is to be pivoted out of its initial position illustrated in  FIGS. 6 and 7  toward the right or toward the left. 
       FIG. 14  shows the first pin  16  with its one slotted link  14  with a fitted pin  17 . The handle  16  for a second bolt  17  is also shown in  FIG. 14  and indicates the position of the lower end of the second slotted link, not visible in  FIG. 14 , as it lies on the side of the first pin  10  turned away from the observer. The second handle  16 , shown in a position at the lower end of the hidden slotted link, which rises from that point in a direction opposite to that of the visible slotted link  14 , and with an oppositely directed slope. 
       FIG. 14  further shows that a pressure spring  18 , designed as a helical spring, is fitted in the hollow first pin  10  and projects a certain length from the hollow pin  10  in downward direction. The pin  10 , with the pressure spring ahead, is pushed into the first sleeve  9  and then still projects from the sleeve  9  a certain length, as illustrated in  FIG. 6 . 
     When the first support  6  is pivoted out of its initial position, after a bolt  17  has been retracted, the first pin  10  will screw down deeper into the first sleeve  9 —due to the interaction of the remaining bolt  17  and the one slotted link  14 —whereby the pressure spring  18  is compressed. When the first support  6  is released, the pressure spring  18  can relax and can push the first support  6  back into its initial position. 
     Mounted on the bottom of the second supporting part  12  is a free-wheeling roller  19  whose axis  20  extends in parallel to the top of the second supporting part  12  and vertically to a line parallel to the horizontal axis  13 . The roller  19  runs on a curved guide rail  21  or  22 , which is part of a guide device  23 . The guide device  23  comprises the two curved guide rails  21  and  22  of mirror-inverted shape and brackets  24  for fixing the guide rails  21  and  22  on the first footplate  7 . The two guide rails  21  and  22  are connected one with the other on one end and are commonly supported at that connection point by the shortest one of the brackets  24 . From there, they extend in mirror-inverted shape around the first sleeve  9  over an angle of somewhat more than 90° each. Their distance from the first footplate  7  increases continuously up to their other free end. With the effect that when the first support  6  is swung out of its initial position ( FIG. 1 ) the second supporting part  12  will be raised continuously as illustrated in  FIGS. 2 ,  3 ,  8 ,  9  and  10 . At the same time, the first supporting part moves a certain distance in downward direction toward the base  1 , whereby the raising effect on the second supporting part  12  relative to the first supporting part  11  is further intensified. 
     Instead of supporting the guide rails  21  and  22  on brackets  24 , it is also possible to provide an upright solid curved wall on the footplate  7  and to use the upper edge of the wall as a guide rail. 
     In addition to the first support  6 , the base  1  further carries a second support  25 , which contrary to the first support  6  shows an undivided design. It consists of a plate surrounded by an upright marginal strip  26 . The marginal strip  26  protects the foot from sliding off the second support  25 . A marginal strip may also be provided on the first supporting part  11  of the first support  6 . The second supporting part  12  preferably does not have such a marginal strip. 
     Mounted on the bottom of the second support  25  is a second sleeve  27  that receives a second pin  28  mounted on a second footplate  29 , the latter being fixed on the base  1 . The second footplate  29  is provided for this purpose, on each side of the second pin  28 , with one row of three bores intended to receive three of the five pins  5  (see  FIG. 16 ). The second footplate  29  is secured on the base  1  by two crew caps  8 .  FIG. 1  shows the second footplate  29  arranged in the middle of a row of pins  5 . By placing it farther to the left or to the right, the second support  25  can be placed closer to or farther remote from the first support  6  in order to adapt the arrangement to golfers of different standing widths. 
       FIGS. 4 and 5  show in detail that a section of the second pin  28 , not engaged in the second sleeve  27 , is surrounded by a torsion spring  30  in the form of a helical spring, the upper end of which is received in the oblong slot  31  in the second sleeve  27  and the lower end of which—not shown in FIGS.  4  and  5 —is fixed on the second footplate  29  or is fitted in a transverse bore in the second pin  28 . When the second support  25  is swung out of its initial position illustrated in  FIGS. 1 and 4 , the torsion spring is tensioned whereby it produces a restoring moment. 
     As can be seen in  FIGS. 4 and 5 , the second sleeve  27  is provided with a second slotted link of V-shaped configuration, viewed from the side, the apex of the V defining the lowermost point of the slotted link  32 . The slotted link is engaged by a second bold  33 , fitted in a second pin  28  and extending in radial direction. The slope of the second slotted link  32  is less steep than the slope of the first slotted link  14 . During a swinging movement, the second support  25  therefore moves down to a lesser degree than the first support  6 . Further, the second slotted link  32  extends over a smaller circumferential angle than the first slotted link  14  so that the potential swinging angle, by which the second support  25  can be swung out of its initial position shown in  FIGS. 1 and 4 , is considerably smaller than the potential swinging angle of the support  6 . As the two rising branches of the second slotted link  32  form together a continuous slotted link, the second support  25  may at any time be swung in either of the two possible swinging directions. 
     Alternatively, the second slotted link  32  may be given an exclusively horizontal design. This limits the swinging angle of the second support  25  which in that case is restricted to a horizontal movement. 
     The arrangement illustrated in  FIG. 1  suited for use by a right-handed golfer. He places his left foot on the second support  25  and his right foot on the first support  6 . To adjust the arrangement to a left-handed person, one would detach the two footplates  7  and  29  and fit the first footplate  7 , in mirror-symmetrical position relative to the position illustrated in  FIG. 1 , on the left side of the base and the second footplate  29 , in mirror-symmetrical arrangement relative to the position illustrated in  FIG. 1 , on the right side of the base  1 . In order to prevent the pressure spring  18  from relaxing in an uncontrolled way and from causing injury during that process, the pressure spring preferably is secured for example by a screw which retains the spring and which engages the pressure spring  18  from the bottom of the hole  1 , through the hole  2  in the base  1 , so as to couple it with the base  1 . 
     Alternatively, it is possible with particular advantage to omit the pins  5  provided in the area of the first footplate  6 , to support the footplate  7  on the plate  1  for pivotal movement about the axis of the central screw cap  8 , and to fix it by two outer screw caps  8  optionally in two positions rotated by 180° one relative to the other that can be transferred one into the other by rotation of the footplate  7  by 180° about the axis of its central screw cap  8 . The second footplate  29  with the second support  25  can be fitted in a mirrored arrangement to complete the conversion of an arrangement for right-handed persons to an arrangement for left-handed persons. 
     The variation of the device illustrated in  FIG. 17  differs from the first embodiment in that the torsion spring  30  and the oblong slot  31  have been omitted. The sleeve  27  has been extended toward the bottom and the V-shaped slotted link  32  has been replaced by a horizontally extending slotted link  32 . A retracting spring  37  is wound about a third bolt  36 , arranged below the slotted link  32  and fitted in the second sleeve  27 , with the legs  37   a  and  37   b  of the spring extending toward the second support  25  and crossing each other on that way. The one leg  37   a  of the retracting spring rests against the second bolt  33 , while the other leg  37   b  rests against the fourth bolt  38 , fitted in the second sleeve  27 , tending to approach it again to the second bolt  33  when a golfer has pivoted the second support  25  and has tensioned the retracting spring  37  by performing the golf swing. 
     The variation of the device illustrated in  FIG. 18  differs from the first embodiment in that the bore  3  and the pins  5  have been removed from the plate  1  and have been replaced by pairs of parallel oblong holes  39  by means of which the first footplate  7  and the second footplate  29  can be infinitely adjusted. Clamping screws  8  that engage the oblong holes  39  serve to clamp the footplates  7  and  29  in their respective positions. 
     LIST OF REFERENCE NUMERALS 
     
         
           1 . Base, plate 
           2 . Two separate bores 
           3 . Two rows of bores 
           4 . Four separate pins 
           5 . Four rows of pins 
           6 . First support 
           7 . First footplate 
           8 . Screw cap, clamping screw 
           9 . First sleeve 
           10 . First pin 
           11 . First supporting part 
           12 . Second supporting part 
           13 . Horizontal axis 
           14 . Slotted link in  10   
           15 . Radial threaded bores 
           16 . Handle 
           17 . Bolt 
           18 . Pressure spring 
           19 . Roller 
           20 . Axis of  19   
           21 . Guide rail 
           22 . Guide rail 
           23 . Guide device 
           24 . Braces 
           25 . Second support 
           26 . Marginal strip 
           27 . Second sleeve 
           28 . Second pin 
           29 . Second footplate 
           30 . Torsion spring 
           31 . Oblong slot 
           32 . Second slotted link 
           33 . Second bolt 
           34 . Locking means 
           35 . Base portion 
           36 . Third bolt 
           37 . Retracting spring 
           37   a . Leg of  37   
           37   b . Leg of  37   
           38 . Fourth bolt 
           39 . Oblong holes