Abstract:
A bowling ball finger insert featuring a pliable plastic cylinder and three vertically disposed ridges whose respective faces define the interface between the insert and a finger hole of a bowling ball.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to a finger insert to permit improved grip and, more particularly, to finger inserts for use in the holes of a bowling ball.  
         [0003]     2. Description of Related Art  
         [0004]     The precise fit of a bowling ball to a bowler&#39;s fingers has long been a sore spot in this popular sport. It stands to reason that a player&#39;s grip on the ball must be sure and secure so that the ball is correctly aimed and propelled down the alley. If the holes into which one inserts one&#39;s fingers to grip the ball are too large, the ball may well slip prematurely from one&#39;s grasp. The extra effort to hold on to a loose ball may be significant. But if the holes are too small, the player&#39;s fingers may become sore and bruised through repeated insertions into the holes. The ball may even hang on to the hand for a moment after release, resulting in further finger damage, as well as gutter balls.  
         [0005]     As a result, the usual tradition for serious bowlers has been to obtain a custom-made ball in which the holes are drilled to match the bowler&#39;s fingers. Generally, such custom holes are available in {fraction (1/32)}-inch increments, making it possible to closely match the dimensions of a bowler&#39;s fingers. However, the human finger is not static. It may swell due to bruising, weight gain, or even to water retention. On the other hand, the finger may shrink due to weight loss. Fingers frequently change diameter during the course of the day; perhaps being smaller in the morning and larger in the evening. In any case, a bowling ball hole that matches the fingers perfectly when it was first drilled may well be too large or too small at a later date. In fact, it is likely that the same hole will alternately be too large and too small.  
         [0006]     Some bowlers attempt to solve the changing finger size problem by having more than one bowling ball, for example, one ball drilled for their fingers at their minimum size and a second ball drilled for the fingers at a maximum size. This solution is not very practical, particularly for a casual player who uses rental balls.  
       SUMMARY  
       [0007]     The present invention aims to provide a simple and inexpensive bowling ball finger hole insert that provides a firm finger grip while automatically adjusting to accommodate changes in the bowler&#39;s finger size. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which:  
         [0009]      FIG. 1  shows a typical bowling ball equipped with inserts according to an illustrative embodiment invention;  
         [0010]      FIG. 2  shows an elevational view of the inserts of  FIG. 1  removed from the bowling ball; and  
         [0011]      FIGS. 3 and 4  are respective end views of opposite ends of the insert of  FIG. 2   
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide automatically-adjusting bowling ball inserts comprising two coaxial hollow cylinders of elastomer.  
         [0013]      FIG. 1  illustrates finger inserts  11  of the preferred embodiment mounted in the finger holes  14  of a bowling ball  10 . The preferred embodiment of an auto adjusting finger insert  11  is further illustrated in FIGS.  2  to  4 . The insert  11  comprises a relatively soft plastic cylinder  13 . The cylinder  13  is preferably made of 90 shore polyurethane molded into shape, and may be a harder polyurethane to suit the taste, e.g., of pro players.  
         [0014]     One end ( FIG. 3 ) of the cylinder  13  is circular, while the other end ( FIG. 4 ) has a flat entry way portion  14 , which is ramped or tapered and blended into the circular contour of the cylinder  13 . The flat portion accommodates the underside of a finger as the finger is inserted into the device  11 .  
         [0015]     The cylinder  13  further includes three vertically disposed ridges  15 ,  17 ,  19  formed on its outer surface  21 . The three ridges  15 ,  17 ,  19  are preferably spaced around the circumference such that respective radii r 2 , r 3 , r 4  lying 120 degrees apart bisect the base ridge  15  and lie adjacent the outer edge  18 ,  20  of each of the side ridges  17 ,  19 . The faces of each of the ridges  15 ,  17 ,  19  which contact the finger hole  14  lie tangent to circle  22 , which is of the same diameter as the hole  14 . The sides of the ridges  15 ,  17 ,  19  lie parallel to the central axis of the cylinder  13 .  
         [0016]     The first ridge  15  preferably extends the entire length of the cylinder  13 , while the other two ridges  17 ,  19  are preferably of an equal length which is shorter than the full length of the cylinder  13 . For example, for an insert whose height “h 1 ” is 1¼ inches, the length “h 2 ” of the shorter ridges may be ¾″. A summary of illustrative dimensions of such an embodiment in inches are:  
                                                       h 1  = 1¼   w 2 , w 3  = ¼″           h 2  = ¾″   t = {fraction (1/16)}           D = {fraction (31/32)}   w 1  = ½″                      
 
         [0017]     Such dimensions are illustrative only and may be varied in different embodiments.  
         [0018]     Various sized inserts will typically be fabricated to accommodate different finger sizes. The outside diameter D of {fraction (31/32)}″ may remain the same, while the radial thickness of the ridges  15 ,  17 ,  19  is varied to permit the radius R 1  of the cylinder  13  to vary to accommodate various finger sizes.  
         [0019]     In operation, an insert  15  may be glued into a bowling ball hole  14 , after which a bowler inserts a finger into the insert  15 . Air spaces formed between the circumference of the bowling ball finger hole  14  and the circumference of the cylinder  14 , as well as the pliability of the plastic material, function to accommodate variations in the finger size of a particular individual.