Abstract:
A golf putting trainer includes a holder for a putter having a shaft and a head, elements for guiding the holder in a curved movement path and elements for holding the putter head in a position perpendicular to the direction of movement of the holder. The golf putting trainer includes elements for adjusting the curvature of the movement path of the holder both vertically and horizontally.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a golf putting trainer comprising a holder for a putter having a shaft and a head, means for guiding the holder in a curved movement path and means for holding the putter head in a position perpendicular to the direction of movement of the holder.  
       BACKGROUND OF THE INVENTION  
       [0002]     On a golf round about 45% of the strokes are putting strokes. It is thus essential to put good in order to be a good golfer.  
         [0003]     In a correct putting swing the head of the putter is perpendicular to the putting line when the ball is hit. If the head is not perpendicular to the putting line the ball will spin and move away from the putting line. A golf green is however seldom totally horizontal which means that gravity influences the path of the ball. Thus, a person performing a putting stroke will therefore have difficulty in determining if path of the ball is due only to influence by gravity or if spin also had an influence.  
         [0004]     There is therefore a need for a golf putting trainer in which a correct putting swing can be teached.  
         [0005]     Several golf putting trainers are known. JP 2000300709 A discloses such a trainer in which a putter head is movable along a guide rail with the head rotatable around a vertical axis a certain degree. This trainer is said to make the user feel if an incorrect putting swing is performed. JP 6126010 A discloses such a trainer in which a holder for a putter is guided by arcuate rails.  
         [0006]     The object of the present invention is to provide an improved golf putting trainer, in which a putter is moved in a path that can be vertically and horizontally curved, the curvature of the path being adjustable in order to adapt the trainer to the length and constitution of the user.  
       SUMMARY OF THE INVENTION  
       [0007]     The object of the invention is obtained by a golf putting trainer comprising a holder for a putter having a shaft and a head, means for guiding the holder in a curved movement path and means for holding the putter head in a position perpendicular to the direction of movement of the holder, characterised by means for adjusting the curvature of the movement path of the holder both vertically and horizontally. By this possibility of adjusting the curvature, the putter can be made to follow the correct putting swing movement for the individual using the trainer.  
         [0008]     In a preferred embodiment, the means for guiding the holder comprises two parallel elongate guide rails supported by a frame, the rails being attached to the frame in their forward and rear ends and in a point therebetween.  
         [0009]     Furthermore, the trainer has means for adjusting the vertical and horizontal position of the ends of the guide rails which are arranged to move the forward or rear ends synchronously so that the guide rails always be parallel to each other. The means for guiding the holder comprises means for preventing rotation of the holder around the axis of the putter shaft and out of a plane comprising the two parallel rails.  
         [0010]     In a first alternative, the means for guiding the holder comprises rollers running on a surface of the rails, wherein at least two rollers being displaced vertically and horizontally in relation to each other are associated with each rail.  
         [0011]     In a second alternative, each rail comprises a groove running along the length thereof, in which rollers protruding from the holder are guided.  
         [0012]     Advantageously, a mirror is attached to the holder and located in a plane parallel to the plane comprising the rails.  
         [0013]     In the first embodiment the holder comprises a vertical wall being perpendicular to the elongate rails and means for removably affix the stroking face of a putter head to said wall, said wall comprising an opening for the part of the putter head comprising the sweet-spot of the putter head.  
         [0014]     In a second embodiment of the invention, the putter is integrated in the holder. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0015]     The invention will now be described with reference to the enclosed figures, of which;  
         [0016]      FIG. 1  shows a schematic perspective view of a golf putting trainer according to a first preferred embodiment of the invention,  
         [0017]      FIG. 2  shows an end part of the frame of the trainer in  FIG. 1 ,  
         [0018]      FIG. 3  shows a section along line III-III in  FIG. 2 ,  
         [0019]      FIG. 4  shows a front view of a holder for a putter in the trainer in  FIG. 1 ,  
         [0020]      FIG. 5  shows a section along line V-V in  FIG. 4 ,  
         [0021]      FIG. 6  shows a view from above of the holder in  FIG. 4 ,  
         [0022]      FIG. 7  shows a perspective view of the holder in  FIG. 4 , and  
         [0023]      FIG. 8  shows a perspective view of a holder according to a second embodiment. 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0024]     A golf putting trainer according to a first preferred embodiment is shown in  FIGS. 1-7 . This trainer comprises a frame  1  for supporting two parallel, elongate guide rails  2  for a holder  3 , in which a putter can be removably affixed. The frame  1  comprises two parallel elongate beams  4  or the like and an upstanding end part, a front end part  5  and a rear end part  6 , the end parts  5 , 6  being attached to the front and rear ends of the beams  4 . Each guide rail  2  is affixed to the adjacent beam  4  in a middle point  7  of the beam and the ends of the rails are supported by adjustment devices  8 , 9  arranged in the front and rear end parts  5 , 6  of the frame  1  to be movable in a vertical and horizontal direction. In the shown example the rails have the form of tubes having a circular section but the tubes can of course have other sections, such as square or rectangular sections. Furthermore, the rails need not be hollow and can consist of rods.  
         [0025]     In  FIGS. 2 and 3  the adjustment device  9  arranged in the rear end part  6  is disclosed. The adjustment device  9  comprises a transversely extending rod  10  which ends are slidable in a vertical plane perpendicular to the length direction of the beams  4  in vertical slots  11  provided in the vertically extending side beams  12  of the rear end part  6 . This rod is rotatably supported in a transverse bar  13  having downwards directed flanges  14  abutting the insides of the side beams  12  of the rear end part  6 . The bar  13  is in the middle thereof provided with a nut  15  co-operating with a threaded bolt  16  being rotatably supported in the upper crossbeam  17  of the rear end part  6 . By rotating the head  18  of the bolt  16  in opposite directions the bar  13  and thereby the rod  10  can be moved upwards and downwards in the slots  11 .  
         [0026]     The adjustment device  9  also comprises two attachment rods  19  for attaching the rear ends of the rails  2  to the adjustment device. The rear ends of these attachment rods are supported by the transverse rod  10  which run through holes  20  in the rear end portions of the attachment rods  19 . The rear end portions of the attachment rods  19  also comprises holes perpendicular to the holes  20  in taps  21  are provided. These taps  21  are affixed to a sleeve  22  having holes corresponding to the holes  20  for the passage of the transverse rod  10  and threaded holes for the affixing of the taps  21 . The transverse rod  10  is threaded at least in parts and the undersides of the taps comprise threads co-operating with the threads on rod  10 . The outer ends of the rod  10  are provided with heads  23 . By rotating these heads  23  the attachment rods  19  can be laterally moved back and forth. The holes  20  have the form of a double cone with bases directed outwards in order to permit angular displacement of the attachment rods  19  in relation to the rod  10 . The rear end portions of the rails  2  are slidably attached to the attachment rods  19 .  
         [0027]     The adjustment device  8  for the front ends of the rails  2  is constructed in the same way as the adjustment device  9  for the rear ends of the rails  2  and need not be described further.  
         [0028]      FIGS. 4-7  show a first preferred embodiment of the holder  3  for a putter. The holder  3  comprises a front wall  24 , a rear wall  25 , two side walls  26 , 27  and a bottom wall  28 . The front wall  24  has an opening  29 , in which the central part of a putter head is to be placed. A resilient element  30  is protruding upwards from the bottom wall  28  on both sides of the opening  29  in the front wall and a self-locking band  31  such as a Velcro™ band co-operating with each element  30  is attached in the front wall and can operated to press this element downwards. Thereby a putter head placed between the elements  30  can affixed to the holder  3  with its stroking face pressing against the front wall and its bottom face pressed against the bottom wall  28 . The resilient element  30  can for example be a metal piece. In the bottom wall two rows of openings  32  for accommodating the elements  30  are arranged so that the location of these elements can be adapted to the type of putter head to be attached to the holder.  
         [0029]     On the side walls  26 ,  27  of the holder, rollers  33 , 34  and  35  are arranged to co-operate with the rails  2  so that the holder is unable to rotate in or move out of the plane comprising the rails  2 . This is accomplished by displacing the rollers  34 , 35  from the roller  33  both vertically and lengthwise.  
         [0030]     The described putting trainer functions in the following way.  
         [0031]     Firstly, the trainer is adapted to the individual who is to use the trainer. For a long individual the radius of the swing is larger than for a shorter individual provided they use the same putting grip. This means that for a short individual the ends of the rails  2  must be higher up than for a long individual. The ends of the rails  2  are also adjustable sideways, i.e. laterally in relation to the length direction. However, the differences of the radius of the swing in a horizontal plane are much smaller than for the differences of the radius in a vertical plane.  
         [0032]     After the trainer has been adapted to the individual using it, the head of the putter attached to the holder will always follow the correct movement path, hitting the ball in a position perpendicular to the putting line, i.e. a line parallel to the length direction of the rails  2 . When the ball is hit by a correct putting stroke, the head of the putter should be slightly above ground. This means that in the lowest position during its movement, the bottom of the holder should almost touch the ground. Therefore, the rails  2  are placed within the height region of the beams  4  of the frame in their attachment points  7  and a distance on the front and rear sides thereof. In order to allow movement of the rails  2  in a direction perpendicular to the rails  2 , the rails are distanced from the beams  4  and attached thereto via distance elements  36 , as can be seen in  FIG. 1 .  
         [0033]     Thus, a putter attached to the holder  3  will always perform a correct putting stroke. All the individual using the trainer has to do is to grip the shaft of the putter, swing and follow the movement of the putter. A correct putting stroke will thereby be learned by motor learning.  
         [0034]     The holder  3  is advantageously also provide with a horizontally disposed mirror  37  having a marking in the middle thereof representing the position of the sweetspot of the putter. This makes it possible for the user to check that he has his/her eyes directly above the ball, which is essential for the aim. When the trainer is used together with a ball, the ball should be placed in the middle of a line between the attachment points  7  of beams  4 .  
         [0035]     In  FIG. 8 a  holder  3 ′ according to a second embodiment of a putting trainer is schematically shown. The putting trainer according to the second embodiment differs from the putting trainer according to  FIGS. 1-7  only in that a putter is integrated in the holder and that the side walls only support two rollers  33 ′,  34 ′ instead of three rollers as in the first embodiment. Otherwise this trainer is constructed in the same way as the trainer according to  FIGS. 1-7  and need not be further described. The putter integrated in holder  3 ′ has a shaft  38  protruding from the front wall  24 ′, which thereby constitutes the putter head.  
         [0036]     The described embodiments can of course be modified in several ways without leaving the scope of the invention. For example, the rails can have grooves along the length thereof, in which rollers are guided. Furthermore, resilient clamping devices or other means can be used to attach a putter head to the holder. The attachment rods can be made angularly displacable with the aid of universal joints instead of holes having the form of double cones or by being made of a bendable material. The attachment rods need no be rods but can be tubes fitting onto or into the end portions of the rails. The bottom wall of the holder can consist of one or several bars instead of a plate as in the disclosed embodiments. The adjustment devices can be different from the described devices, for example can the front and rear end parts of the frame be laterally movable as a whole in order to accomplish the sidewise movements of the rail ends and the side beams of the front and rear end parts can be made of two telescopic portions. The scope of invention should therefore only be restricted by the content of the enclosed set of patent claims.