Abstract:
A putting stroke training device having a housing with serrations on the bottom for engagement with a carpet or rug and an elongated top opening. A simulated club head is slidable in a straight line along the inside of the housing parallel to the top opening in such a manner that it cannot move upward significantly. A manually operable elongated shaft extends up from the housing at the top opening and has its lower end coupled to the simulated club head by a universal joint.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a training or practice device for aiding a golfer to master a putting stroke. 
   2. Prior Art 
   Various putting stroke training or practice devices have been proposed heretofore in which the head of an actual putter or a simulated putter is constrained to move through a predetermined arc when the user swings the putter shaft. Examples of such proposals are disclosed in the following U.S. patents: Eisenberg U.S. Pat. No. 2,084,902; Pelz U.S. Pat. No. 4,437,669; Grant et al U.S. Pat. No. 5,125,844; and Springer U.S. Pat. No. 5,437,458. In addition, Lee U.S. Pat. No. 5,435,547 proposes a device designed for arcuate movement of the putter head along a predetermined “swing arc.” 
   Various other putting stroke training or practice devices have been proposed in which the putting head is intended to move in a straight line horizontally, but they lack any constraint against upward movement of the putter head, which would be inconsistent with the fundamental purpose of training the user to move the club head in a straight line. Devices of this type are shown in King U.S. Pat. No. 3,885,796 and Adams U.S. Pat. No. 6,159,106. 
   Arcuri U.S. Pat. No. 6,350,207 discloses a putting stroke training device which does limit the stroke to a horizontal straight line, but has the ball striker located a substantial distance in front of the lower end of the club shaft and in this respect does not realistically simulate what a golfer experiences when using an actual putter on a golf course. 
   Lee et al U.S. Pat. No. 6,461,246 discloses a putting stroke training device for use with an actual putter. It has a guideway for the head of the putter which permits upward arcuate movement of the club head at the end of the backstroke. In addition, during a putting stroke the club head has to move beyond this guideway to strike the ball and in doing so it is free to move upward. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a putting stroke training or practice device which has a simulated putter head that is restrained against upward movement during a simulated putting stroke. The preset invention limits it the simulated putter head to straight-line motion, as well as positioning the simulated putter head in the usual position abutting the lower end of the club shaft 
   A principal object of this invention is to provide a novel and advantageous putting stroke training or practice device which trains the user to perform a straight-line stroke of a simulated putter head that is realistically positioned with respect to its club shaft essentially the same as the head of an actual putter is positioned with respect to its club shaft. 
   Further objects and advantages of this invention will be apparent from the following detailed description of presently preferred embodiments thereof illustrated in the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top plan view of a first embodiment of the present invention with the club shaft detached; 
       FIG. 2  is a horizontal longitudinal section through the  FIG. 1  device taken just below its top wall, at line  2 — 2  in  FIG. 3 ; 
       FIG. 3  is a vertical longitudinal section taken along the line  3 — 3  in  FIG. 2 ; 
       FIG. 4  is a vertical cross-section through the upper part of this device, taken along the line  4 — 4  in  FIG. 1 ; 
       FIG. 5  is a fragmentary vertical section at the universal joint connecting the lower end of the club shaft to the simulated club head of the device, taken along the line  5 — 5  in  FIG. 4 ; 
       FIG. 6  is a fragmentary perspective view showing the slidable arrangement of the simulated club head in a second embodiment of the invention; 
       FIG. 7  is a view similar to FIG.  6  and showing the slidable arrangement of the simulated club head in a third embodiment of the invention; 
       FIG. 8  is a longitudinal section showing the guide rail supporting the simulated club head at one side of the device; and 
       FIG. 9  is a perspective view showing a golfer using the present training or practice device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Before explaining the present invention in detail it is to be understood that the invention is not limited in its application to the particular arrangements shown and described since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. 
   Referring to  FIG. 9 , the putting stroke training or practice device of the present invention has an elongated, generally rectangular housing  10  with an elongated narrow opening  11  in its top wall  12 . The user stands as shown in this Figure and grasps a hand grip  13  on the upper end of an elongated cylindrical shaft  14  that simulates the shaft of a putter. On the lower end of shaft  14  is a universal joint  15  ( FIGS. 4 ,  5  and  8 ) which extends down through the housing opening  11  into the interior of housing  10  and is connected there to a rectangular body  16  ( FIGS. 6 and 7 ) that simulates the club head of a putter. 
   As shown in  FIG. 5 , the lower end of shaft  14  terminates in an externally screw-threaded stem  17  which is threadedly received in a complementary screw-threaded recess  18  extending down from the top of the upper member  19  of the universal joint.—Alternatively, a golf club shaft can be epoxy glued to the upper member  19  of the universal joint.—At its lower end the universal joint member  19  presents circular ears  20  and  21  on opposite sides of a flat-sided recess  22  which is open at the bottom of universal joint member  19 . A pivot pin  23  extends across recess  22  and is fixedly held in the lower end ears  20  and  21  of universal joint member  19 . Pin  23  defines a first pivot axis L in the universal joint which extends along the direction of elongation of the top wall opening  11  in housing  10 . 
   A second, lower member of the universal joint in the form of a flat-sided plate  24  is slidably received in the bottom recess  22  in the upper universal joint member  19 . Plate  24  has a rounded top face  25  that slidably engages a complementary top surface  26  of recess  22 . As shown in  FIG. 4 , the second universal joint member  24  projects laterally beyond the ears  20  and  21  and terminates in coaxial cylindrical stubs  24   a  and  24   b  which define a second axis T of the universal joint that extends perpendicular to the longitudinal axis L and intersects it. 
   As shown in  FIG. 4 , the simulated putting head  16  is formed with an oblong central opening  27  located immediately below the longitudinal top opening in housing  10 . At this opening, body  16  is bent downwardly to form a flange  28  which borders the opening  27 . 
   Right-angled brackets  29  and  30  are bolted to the bottom of the simulated club head  16  next to flange  28 . The brackets rotatably receive the stubs  24   a  and  24   b  of the lower member  24  of the universal joint and support it at the transverse axis T of the universal joint. 
   Housing  10  has flat opposite side walls  31  and  32 , each of which fixedly supports a corresponding horizontally elongated ball bearing raceway  33  or  34  extending lengthwise of housing  10  parallel to its top wall opening  11 . Attachment brackets  35  and  36  ( FIG. 2 ) affix raceway  33  to the adjacent side wall  31  of housing  10 . Each of these brackets has the vertical cross-sectional shape shown for bracket  36  in  FIG. 4 , from which it will be evident that the inwardly offset upper part of the bracket spaces the raceway inward from the housing side wall  31 . Similar brackets  37  and  38  affix the opposite raceway  34  to the adjacent side wall  32  of housing  10 . 
   The simulated club head  16  carries respective elongated ball retainers  39  and  40 , each having outwardly curved top and bottom lips  39 U and  39 L, and  40 U and  40 L, respectively, which hold upper and lower sets of anti-friction balls B against oppositely curved upper and lower lips of the corresponding raceways  39  and  40 . As shown in  FIG. 4 , the ball retainers  39  are bolted to the bottom of simulated club head member  16 . 
   With this arrangement, the user can practice a putting stroke by moving the handle  14  in such a manner as to slide the simulated club head  16  along the inside of housing  10  in a straight-line, horizontal path inside the housing. The user can adjust handle  14  to different angles both transverse to the housing and longitudinally of it. The sliding support for the simulated club head  16  prevents the user from deliberately or accidentally moving it upward any significant amount during the putting practicestroke. 
     FIG. 5  shows a second embodiment of the invention which differs from the first in the slidable support for the simulated club head. The opposite sides  31  and  32  of housing  10  carry elongated horizontal guide tracks  51  and  52  of channel-shaped cross-section with respective inwardly projecting horizontal flanges  51 U,  51 L,  52 U and  52 L at the top and bottom. The simulated club head is a flat rectangular plate  53  that spans the distance between the guide tracks and presents downwardly projecting flanges  54 , each with a close running fit in the corresponding guide track. The flanges of the simulated club head have rounded bottom surfaces that slidably rest on the lower flanges  51 L and  52 L of the guide tracks, while the top of plate  53  has a close clearance from the top flanges  51 U and  52 U of the guide tracks. 
     FIG. 7  shows a third embodiment of the invention which is generally similar to the second but differs from it in that the simulated club head  53 ′ does not completely span the distance between the guide tracks  51  and  52  but instead positions it opposite side flanges  54 ′ and  55 ′ slightly inward from the respective guide tracks. These flanges on the simulated carry rollers R which tide on the lower flanges  51 L and  52 L of the guide tracks and have a slight clearance from the top flanges  51 U and  52 U. 
   From the foregoing description, taken in conjunction with the accompanying drawings, it will be evident that the present invention is adapted for incorporation in a variety of embodiments, each capable of providing the desired training of a user to perform a straight-line putting stroke.