Abstract:
An alignment guide for practice putting has a base with perpendicular target and putter face lines. An unobstructed gap extends away from the putter face line along the target line. A pair of guide rails are secured to the base in parallel relationship to and on opposite sides of the target line and spaced apart by a distance slightly greater than the distance from the toe to the heel of the putter head. The putter head can, therefore, move freely between, but be guided by, the rails. An adjustable stop limits the backswing of the putter head to allow comparison of the length of the backswing with the travel distance of the ball. An adjustable pair of stops simultaneously limiting travel of the toe and the heel of the putter head in the follow through confirm that the putter face has remained square to the target line.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates generally to golf training equipment and more particularly concerns a guide for assisting a golfer to properly align the golfer&#39;s body and putter in preparation for and execution of a correct putting stroke. 
   Golfers have, for centuries, sought ways to lower their score. On a par 72, 18 hole course, 36 strokes are allotted for putting. The putter is the most used club in the golfer&#39;s bag. Improvement in putting skill is, therefore, a major contributor to significant improvement in golf scores. Over the years, two keys have come to be widely accepted as common to the mechanics of good putting. The putter face must be square to the target line and the putter head should be accelerating at the moment of impact with the ball. 
   There are techniques golfers can use to achieve the correct conditions at the moment of impact. For example, the longer the putting stroke maintains the putter head in a square condition, the more likely that the putter face will be square at the moment of impact. And the longer the follow-through in relation to the backswing, the more likely that the putter head will be accelerating at the moment of impact. Also, if the putting stroke is to be consistent, the position of the golfer in relation to the ball and the target line must be consistent. The clearer the reference lines, the easier it will be to maintain this consistency. It is easier, for example, to always position the golfer&#39;s eyes directly over the ball than to always position the golfer&#39;s eyes at some point which is not directly over the ball. It is also easier to always position the feet and shoulders on a line parallel to the target line than to always position the feet and shoulders at some angle which is not parallel to the target line. 
   It is, therefore, an object of this invention to provide an alignment guide for practice putting which facilitates consistent alignment of the golfer&#39;s putting stance in relation to a golf ball and a target line. Another object of this invention is to provide an alignment guide for practice putting which facilitates consistent alignment of the putter head position in relation to a golf ball and a target line. A further object of this invention is to provide an alignment guide for practice putting which structurally guides the putter head in a path parallel to the target line for a substantial portion of the backswing and follow-through. Yet another object of this invention is to provide an alignment guide for practice putting which structurally limits the backswing of the putting stroke to one of several distances selectable by the golfer. Yet another object of this invention is to provide an alignment guide for practice putting which structurally limits the follow-through of the putting stroke to one of several distances selectable by the golfer. It is also an object of this invention to provide an alignment guide for practice putting which provides feedback to the golfer as to whether the putter face has remained square to the target line during the follow-through. Still another object of this invention is to provide an alignment guide for practice putting which provides physical feedback to the golfer as to whether the putter face has opened in relation to the target line during the follow-through. An additional object of this invention is to provide an alignment guide for practice putting which provides physical feedback to the golfer as to whether the putter face has closed in relation to the target line during the follow-through. Another object of this invention is to provide an alignment guide for practice putting which has putter head guide rails which are adjustable in relation to each other so as to accommodate any configuration of putter head. A further object of this invention is to provide an alignment guide for practice putting which has putter head guide rails which are adjustable in relation to a target line so as to accommodate the putting style of the golfer. 
   SUMMARY OF THE INVENTION 
   In accordance with the invention, an alignment guide is provided for practicing striking a golf ball with a head of a putter. The guide has a base with perpendicular target and putter face lines which intersect at a point on an interior portion of the base. An unobstructed gap extends away from the putter face line along the target line from a beginning point which is less than a radius of a golf ball from the putter face line. A pair of guide rails are secured to the base. The rails are in parallel relationship to and on opposite sides of the target line and are spaced apart by a distance slightly greater than the distance from the toe to the heel of the putter head. The putter head can, therefore, move freely between, but be guided by, the rails. It is preferable that the guide rails and the gap be symmetrically arranged in relation to the target line, so that the same guide can be used by right or left handed golfers. It is also preferred that the gap have edges which diverge from their beginning point so that the guide will not impede or redirect the path of the ball after it is struck. 
   In one embodiment, the alignment guide includes a stop for limiting travel of the putter head from the putter face line away from the gap. This affords the golfer a visible mechanism for comparing the length of the backswing associated with the travel distance of the ball after it is struck. This can be accomplished, for example, by providing at least one aperture through a portion of the base on the opposite side of the putter face line as the gap and between the rails, with each aperture being sized to receive the stem of a golf tee. Preferably, the apertures are aligned on an axis parallel to the target line and are spaced at equal intervals. Most preferably, the aperture axis will be coincident with the target line. The golfer can thus insert a golf tee through a selected aperture into the ground, selection being based on the length of the putt. 
   In another embodiment, the alignment guide includes a pair of stops for simultaneously limiting travel of the toe and the heel of the putter head from the putter face line along the gap. The golfer will have physical confirmation that the putter face has remained square to the target line if the stops are simultaneously struck. This can be accomplished, for example, by providing at least one pair of apertures through the base on the same side of the putter face line as the gap and between the rails. Each pair of apertures straddles the gap and is aligned on an axis parallel to the putter face line. Each aperture is sized to receive the stem of a golf tee. Preferably, corresponding ones of the pairs of apertures are aligned on axes parallel to the target line and the pairs of apertures are spaced at equal intervals. Most preferably, the axes of corresponding ones of the pairs of apertures are symmetrically displaced from the target line. The golfer can thus insert tees through a selected pair of apertures into the ground, selection being based on the desired length of square follow-through for the putt. 
   Preferably, each of the guide rails is a length of angle iron with one flange of each angle iron biased against the base. For example, a pair of spring biased clamps can be extended through spaced apart apertures in the flange and through aligned slots in the base. The clamps are slidable in the slots against,the bias to position the rails. Thus, the rails can be permanently engaged against the base and manually slidable to a spacing that will accommodate any putter head with the golfer&#39;s desired ball contact point on the target line, yet sufficiently firmly engaged so as to not be shifted by any contact with the putter head. 
   The surface of the base on which the rails are disposed is preferably a mirror and the target and putter face lines are disposed on the mirror so as to give the golfer visual feedback as to positioning of the golfers head and shoulders in relation to the ball. At least one pair of parallel lines may also straddle the target line to facilitate parallel alignment of the rails. Preferably, the facilitating lines are symmetrically displaced form the target line. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: 
       FIG. 1  is a top plan view of a preferred embodiment of the base of the alignment guide with a golf ball and putter head superimposed thereon; 
       FIG. 2  is a cross-sectional view taken along the line  2 — 2  of  FIG. 1  with a preferred embodiment of the guide rails secured thereon; 
       FIG. 3  is a cross-sectional view taken along the line  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a cross-sectional view taken along the line  4 — 4  of  FIG. 1  with the guide rails of FIG.  2  and the backswing and follow through stops added; and 
       FIG. 5  is a top plan view of a preferred embodiment of the guide base, rails and stops with a golf ball and putter head superimposed thereon. 
   

   While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
   DETAILED DESCRIPTION 
   Looking first to  FIG. 1 , a preferred embodiment of the alignment guide  10  is illustrated. The guide  10  has a flat, substantially rigid base  11  with perpendicular target and putter face lines  13  and  15  which intersect at a point  17  on an interior portion of the base  11 . An unobstructed gap  19  extends away from the putter face line  15  along the target line  13  from a beginning point  21  which is less than a radius of a golf ball  23  from the putter face line  15 . Thus, a golf ball  23  can rest; in the gap  19  with the intended point of contact  25  on the golf ball  23  being tangent to the face  27  of the putter head  29  when the face  27  is aligned on the putter faceline  15 . It is preferred that the gap  19  be symmetrical in relation to the target line  13 . It is also preferred that the gap  19  have edges  31  and  33  which diverge from the beginning point  21  of the gap  19  so as not to impede the travel of the ball  23  after it has been struck. 
   Looking at  FIGS. 1 ,  2  and  3 , the guide also includes a pair of guide rails  35  and  37 . Each of the guide rails  35  and  37  is preferably a length of angle iron with a pair of apertures  39  and  41  spaced apart in one of its flanges  43  or  45 . As shown in  FIG. 1 , the base  11  has four key-hole shaped slots  47 ,  49 ,  51  and  53  which are longitudinally aligned in pairs parallel to the putter face line  15  and spaced apart along the length of the base  11 . Looking at  FIGS. 2 and 3 , the guide  10  also has a plurality of clamps  55  which are adapted to secure the guide rails,  35  and  37  against the base  11 . The positioning of the slots  47 ,  49 ,  51  and  53  in the base  11  is such as to permit the guide rails  35  and  37  to be secured to the base  11  parallel to and on opposite sides of the target line  13  with the rails  35  and  37  spaced apart by a distance slightly greater than a distance from a toe  57  to a heel  59  of the putter head  29 . The clamps  55  are preferably rivet-like members with a compression spring  61  between the opposite heads of the rivet  55 . The rivets  55  extend through the apertures  39  and  41  in the guide rail flanges  43  and  45  with the springs  61  on the interior portion of the angle iron guide rails  35  and  37 . 
   As shown in  FIG. 4 , the apertured flanges  43  and  45  of the guides  35  and  37  can be aligned on the key hole shaped slots  47 ,  49 ,  51  and  53  with the heads of the respective rivets  55  aligned with the circular portions of the slots  47 ,  49 ,  51  and  53 . The rivets  55  can then be pressed against the bias of the spring  61  so that one head of each rivet  55  passes through the round portion of its slot  47 ,  49 ,  51  and  53 . The damp or rivet  55  can then be slid into the narrower portions of the slots  47 ,  49 ,  51  and  53  and released to bias so that the bias of the springs  61  presses the apertured flanges  43  and  45  against the surface of the base  11 . In this condition, the clamps  55  are manually slidable in the slots against bias by a significant force to reposition the rails  35  and  37  as desired on the base  11 . To facilitate proper alignment of the guide rails  35  and  37  at least one and, as shown, three pairs of parallel lines  63 ,  65  and  67  straddle the target line  13 . As shown, it is preferred that these facilitating lines  63 ,  65  and  67  be symmetrically displaced from the target line  13 . 
   Looking again at  FIG. 1 , the base is also provided with at least one and as shown five apertures  69  which extend through the portion of the base  11  which is on the opposite side of the putter face line  15  as the gap  19 . The apertures  69  are aligned between the guide rails  35  and  37 , preferably on an axis parallel to the target line  13  and most preferably on the target line  13 . It is also preferable that they be spaced at equal intervals. As best seen in  FIG. 5 , each of the apertures  69  is sized so as to receive the stem  71  of a golf tee  73  therein. As seen in  FIG. 5 , the tee  73  will limit the length of the backstroke of the putter head  29 . The golfer can insert the tee  73  in a selected one of the apertures  69  depending on the intended length of the putt to be practiced. 
   As also seen in  FIG. 5 , pairs of apertures  75  and  77 , as shown three pairs, extend through the base  11  on the same side of the putter face line  15  as the gap  19  and between the rails  35  and  37 . Each pair of apertures  75  and  77  straddles the gap  19  and is aligned on an axis  79  which is parallel to the putter face line  15 . As best seen in  FIG. 5 , each of the apertures  75  and  77  is also sized to receive a stem  79  of a golf tee  83  therein. As shown, corresponding ones of the pairs of apertures  75  and  77  are aligned on one of the pairs of facilitating lines  67 . This pair of lines  67  is proximate the outer extremities of, but within the face  27  of the putter head  29 . Also as shown, the axes  79  are preferably spaced at equal intervals and the apertures  75  and  77  are symmetrically displaced from the target line  13 . Thus, the follow-through of the putter head  29  will be limited by contact with the tees  83  inserted through pairs of apertures  75  and  77  on a selected axis  79 . More importantly, as the face  27  of the putter head  29  comes into contact with the tees  83 , the golfer will receive feedback as to whether the face  27  of the putter head  29  has remained square to the target line  13 . If the putter head  29  contacts both tees  75  and  77  simultaneously, then the face  27  is square. If the face  27  first contacts the tee  83  closest to the golfer, then the putter face  27  has been opened. If the face  27  first contacts the furthermost tee  83 , then the putter face  27  has been closed. 
   Preferably, the surface of the base  11  against which the guide rails  35  and  37  are secured is a mirror  85  with the target line  13 , putter face line  15 , and pairs of facilitating lines  63 ,  65  and  67  disposed on the mirror  85 . 
   In use, the golfer places the head  29  of his putter on the mirrored surface with the desired contact point of the putter face  27  aligned on the target line  13  and the putter face  27  aligned on the putter face line  15 . The golfer then slides the guide rails  35  and  37  into a parallel condition spaced approximately ¼ inch outside of the toe  57  and heel  59  of the putter head  29 . It should be noted that, while it is preferred that the positioning of the putter head  29  is such that the rearmost point on the ball  23  will be centered on the putter face  27 , some golfers may prefer to strike the ball  23  on the putter face.  27  at a point closer to the toe  57  or heel  59  of the putter head  29 . The guide  10  permits such an adjustment, the guide rails  35  and  37  simply being adjusted so as not to be symmetrically displaced from the target line  13 . With the rails  35  and  37  properly spaced, the golfer selects a target (not shown) and positions a golf ball  23  at any desired distance from the target. The golfer then lays the guide  10  on the ground  87  with the mirror surface  85  up. The guide  10  is positioned with the ball resting on the ground  87  in the gap  19  of the base  11  with the contact point  25  of the ball  23  centered on the target line  13  and tangent to the putter face line  15 . Given the selected distance to the target (not shown), the golfer then chooses the desired limit for the backswing of the putter head  29  and inserts a golf tee  73  into the selected aperture  69 . The golfer also selects the desired length for the square follow through and inserts a pair of golf tees  83  into the apertures  75  and  77  aligned on the axis  79  which is closest to the point of this square follow through. The golfer then assumes a putting stance by aligning the feet and shoulders (not shown) in relation to the target line  13  or any of the parallel lines  63 ,  65  or  67  and by positioning the eyes directly over the ball  23 . The mirror surface  85  assists the golfer in confirming the proper positioning of the shoulders and eyes. The putter head  29  is inserted between the guide rails  35  and  37  with the face  27  aligned with the putter face line  15 . The direction of the backswing and follow-through are limited by the guide rails  35  and  37  and the length of the backswing is determined by the golf tee  73  while the length of the square portion of the followthrough is determined by the golf tees  83 . After several putts at a given target (not shown), the golfer can adjust the alignment of the target line  13  or change the apertures in which the golf tees  73  and  83  are inserted so as to achieve the proper stroke. With continued practice, the golfer can correlate the length of the backswing and follow through to desired putt distances. 
   In a satisfactory prototype, the base  11  is an approximately 18 inches long by 9 inches wide by ⅛ inch thick laminated acrylic mirror. Five backswing limiting apertures  69  are spaced on one inch centers on the target line  13  beginning two inches from the back edge of the base  11 . Three pairs of follow through limiting apertures  75  and  77  are spaced on one inch centers one inch from the front edge of the base  11 . The putter face line  15  is approximately 8¼ inches from the front edge of the base  11  and the beginning point  21  of the gap  19  is approximately ¼ inch forward of the putter face line  15 . The slots  47 ,  49 ,  51  and  53  are spaced along the length of the base  11  by a distance of ten inches. The numbers of and spacing of apertures  69  and  75  and  77  may vary. The number of pairs of alignment facilitating lines  63 ,  65  and  67  may be varied. In the prototype, it was found desirable to color code the alignment facilitating lines  63 ,  65  and  67  and the target line  13  for the convenience of the golfer in positioning the guide rails  35  and  37 . 
   Thus, it is apparent that there has been provided, in accordance with the invention, an adjustment guide for practice putting that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.