Jig for boring finger holes in bowling balls

March 31, 1959

W. L. NEFF

2,879,679

JIG FOR BORING FINGER HOLES IN BOWLING BALLS

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March 31, 1959 w. i_. neff

2,879,679

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ATTORNEYS

United States Patent Office

2,879,679

Patented Mar. 31, 1959

2,879,679

JIG FOR BORING FINGER HOLES IN BOWLING BALLS

Wilber L. Neff, Eugene, Oreg.

Application February 18,1957, Serial No. 640,646

Claims. (Cl. 77—63)

This invention relates to a jig for boring finger holes in bowling balls and more particularly to a device in which a bowling ball may be secured and which may be positioned in a drill press with the frame of the device in a predetermined position and all of the finger holes bored in the ball without moving the frame from such predetermined position, the locations and angles of the various holes being obtained by pivotal movement of ball supporting cradles mounted in such frame to positions indicated by scales carried by the device.

The jig of the present invention is particularly adapted for use with the finger hole position determining device disclosed and claimed in my copending application Serial No. 640,716, filed February 18, 1957. In the jig of the present invention, the ball is supported in a first cradle which is pivotally supported in another cradle for movement about an axis through the center of the ball and such other cradle is supported in the frame of the device for movement about an axis at right angles to the first mentioned axis and tangent to a ball at its lowermost point. Scales are provided for indicating the position of such cradles as a result of their pivotal movement about the axis referred to and the data for adjusting the cradles relative to such scales is obtained from the device of my copending application, above referred to. The cradles of the present device are originally brought to zero position in which the two cradles are upright when the device is resting upon a horizontal surface and the ball is then placed in and clamped in the first cradle in a predetermined position, determined by markings on the ball. That is to say, a zero point indicated by such markings is placed uppermost and the ball aligned by known markings thereon with a selected axis thereof parallel to the pivotal axis of the second cradle referred to. With the ball in the position just discussed, the jig is aligned with the drill of a drill press so that the zero point, above referred to, is below and in axial alignment with the spindle of the drill press. This position of the device is the same for finger hole boring operations on all bowling balls and the device may be permanently secured to a drill press table in such position. By pivoting the two cradles about their axes in accordance with data obtained from the finger hole position determining device of my copending application, and selecting the proper sized drill in accordance with data. obtained from finger size measuring gauges, each separate hole may be drilled in the bowling ball at the correct angle and position with respect to predetermined axes of the ball.

. An obiect of the invention is therefore to provide an improved jig for enabling holes to be bored in bowling balls at predetermined angles and positions with respect to predetermined axes of the ball.

_: Another object of the invention is to provide an improved device which enables all of the finger holes in bowling balls to be bored in such balls at predetermined positions and angles without shifting the base of the device relative to the axis of the spindle of a drill press.

Another object of the invention is to provide an improved device for holding a bowling ball during boring of the finger holes therein in which the ball is clamped in the device in a predetermined position and thereafter pivoted about two spaced axes at right angles to each other to enable such finger holes to be bored in proper angular relation to each other and so as to be properly spaced from each other.

A further object of the invention is to provide a jig for holding a bowling ball while boring finger holes therein which are correctly spaced from each other and which bear an angular relation to each other and to selected axes of the ball, such that the axes of such holes all pass through a laterally extending central axis of the ball and through points opposite such holes on a great circle of the ball which is perpendicular to such lateral extending axis of the ball.

Other objects and advantages of the invention will appear in the following description of the preferred embodiment thereof shown in the attached drawings of which:

Fig. 1 is an isometric view showing the device of the present invention mounted in a drill press and having a bowling ball secured therein;

Fig. 2 is an exploded view of the device of Fig. 1 with the bowling ball omitted;

Fig. 3 is a fragmentary vertical cross section showing the structure of one of the pivotal mountings for the cradles of the device;

Fig. 4 is a diagrammatic view showing the outline of a bowling ball in elevation and indicating the position and angular relation of finger holes in such bowling ball in accordance with the present invention and also indicating the relative position of finger engaging surfaces of finger receiving elements of the cooperating device, referred to above, for determining the correct position and angle of the finger holes;

Fig. 5 is a view similar to Fig. 4 taken at right angles to that of Fig. 4;

Fig. 6 is a diagrammatic plan view showing the outline of a bowling ball in plan and indicating the measurements obtained by the determining device referred to above; and

Fig. 7 is a view similar to Fig. 6 indicating the manner in which the data obtained from such determining device is employed in the jig of the present invention to locate the finger holes in a bowling ball.

Referring to Figs. 1 and 2 of the drawings, the jig of the present invention includes a frame 10 of open top construction having a bottom wall 12, side walls 14, a front wall 16 and a rear wall 18. The front and rear walls 16 and 18 have aligned apertures 20 therein, each of which receive the shank of a flanged pivot member 22, the details of which are shown in Fig. 3. Such pivot member is held in position by a screw 26 extending eccentrically through the pivot member 22 and a flanged nut 28 having a circular body portion 29 fitting within a circular counter bore in the pivot member 22. The eccentric position of the screw 26 prevents the nut 28 from turning on the screw so that the screw 26 must be turned relative to the pivot member 22 and nut 28 to separate the nut 28 from the pivot member 22. The pivot members 22 are employed to pivotally support a first cradle 30 in the frame 10. The cradle 30 has side walls 32 and 33, a front wall 36 and rear wall 38, and has an open top and an open bottom. The shank of the pivot members 22 are also received in aligned apertures 40 in the front and rear walls 36 and 38 of the cradle 30. The cradle 30 is thus pivotally supported in the frame 10 about a horizontal axis through the center of the pivot members 22. The front wall 36 of the cradle 30 is adja2)879,679

3..

cent the front wall 16 of the frame 10 and is held in such position by the corresponding pivot member 22, screw 26 and nut 28, a washer 42 being positioned between the walls 36 and 16, as shown most clearly in Fig. 3. Similarly, the rear wall 38 of the cradle 30 is adjacent the 5 rear wall 18 of the frame 10 and spaced therefrom by a washer 42. The cradle 30 is: sufficiently smaller in lateral dimension that it may pivot about the axis defined' bythe centers of the pivot members 22.

The rear wall 38 of the cradle 30 extends upwardly 10 and has an arcuate upper edge concentric with the axis through the pivot members 22. Such upper edge is provided with a scale 44 preferably graduated each way from a zero central position in thirty-seconds of an inch. The radius of the edge containing the scale 44 is pref- 15 erably made equal to the diameter of the bowling ball into which finger holes are to be bored. The rear wall 18 of the frame 10 also extends upwardly and at its upper end terminates in an index point 46. The index point 46 registers with the zero graduation of the scale 44 when 20 the cradle 30 is in its upright position and the base of the frame 10 is on a horizontal surface. The rear wall 18 of the frame 10 has an aperture 48 therein which receives a headed screw 50 which also passes through an arcuate slot 52 in the rear wall 38 of the cradle 30. The slot 25 52 is concentric with the axis of the pivot members 22. The screw 50 also receives a washer 54 and thumb nut 56 and it will be apparent that the cradle 30 may be pivoted about the axes of the pivot members 26 and held in adjusted position by tightening the thumb nut 56 on 30 the screw 50.

The side walls 32 and 34 of the cradle 30 have aligned apertures 58 therein which receive the shanks of pivot members 59 which are similar to the pivot members 22. The pivot members 59 form a pivotal support for a sec- 35 ond cradle 60, such second cradle having side walls 62 and 64 also having aligned apertures 66 therein. The apertures 66 also receive the shanks of pivot members 59 and such pivot members 59 are held in position by nuts 28 and screws 26 with washers 42 between the adjacent 40 side walls of the cradle 30 and the cradle 60. The pivotal axis through the pivot members 59 is at right angles to the pivotal axis through the pivotal members 22 and is spaced above such axis through the pivot members 22 a distance equal to the radius of the bowling ball in which 45 finger holes are to be bored.

The side wall 64 of the second cradle 60 extends upwardly and has an arcuate upper edge provided with a scale 68, the edge having the scale 68 being concentric with.the pivotal axis of the cradle 60, i.e., the axis through ⁵⁰the centers of the pivot members 59. The scale 68 preferably has a radius equal to the radius of the bowling ball referred to and preferably is graduated each way from a central zero position in thirty-seconds of an inch. The side wall 34 of the cradle 30 also extends upwardly and terminates in an index point 70 adjacent the scale 68. The index point 70 is in registry with the zero point, just mentioned, when the cradle 60 is upright, assuming that the cradle 30 is also upright. The side wall 34 of the cradle 30 has an aperture 72 just below the index point 70, which θθ apertures receives a headed screw 74 which also extends through an arcuate slot. 76 in the side wall 64 of the cradle 60 and. has positioned: thereon a washer 78 and thumb nut 80. The slot 76 is. also concentric with the-axis through the: pivot, members 59. The cradle 60 is braced by front and rear walls 81 which'are lower than the: side walls 62 and 64 and the dimension of the cradles 60 with respect to a direction to the front and rear of the device is sufficiently less than the distance between the front and rear walls 36 and 38 of the cradle 30 that 70 the' cradle 60 may pivot about an axis through the centers of the pivot members 59. It will be apparent that the-cradle 60 may be: held . fir adjusted position by tightening the thumb nut 80 on the screw 74.

A bowling: ball· 82 (Fig. 1) may be secured in position in the cradle 60, which cradle has a bottom wall 84 (Fig. 2) which has therein an enlarged circular aperture 86 for receiving the lower portion of a bowling ball. The cradle 60 is also provided with a removable clamping plate 88 which has reinforcing flanges 90 along its front and rear edges and an enlarged circular aperture 92 registering with the aperture 86 in the- bottom wall 84 of the cradle. The side wall 64 of the cradle 60 has a pair of lugs 94 bent inwardly from siich Wall and engaging over the rear corners of the top of the plate 88 when such plate is in ball clamping position. The side wall 62 of the cradle 60 has an upstanding threaded stud 96 and the plate 88 has a notch 98 in its front edge, which: notch is adapted to fit around the-stud 96.

The bowling ball 82 may be positioned in the cradle 60 with its lower portion engaging in the aperture 86. The plate 88 may then have its rear corners clipped under the lugs 94 of the cradle 60 so that the; notch: 98 . receives the threaded stud: 96 of the· cradle; 60' and the upperportion of the ball is-received in the aperture 92. A washer 100 and thumb nut 102 may then be threaded onthe stud 96 to clamp the upper plate in position· The notches 104 in the clamping plate 88 allow the plate to pass the head of the screw 74 when; the' cradle 60' is pivoted with respect to the cradle 30; The ball 82 is held; in the. cradle 60 so that the pivotal· axis· of such'; cradle through the pivot members 59 passes through: the center of the ball and such that the axis of the cradle 30 through the pivot members 22 is tangent to the lowermost point of the ball.

. After the bowling ball has been secured in proper position: in the cradle 60 and clamp therein by the plate: 88 and thumb nut 102, the jig of the present invention may: be mounted in a predetermined· position on the table 105 of a drill press having a chuck· 106 for receiving a’ drill 108. Alternately, the frame 10 of the device may be permanently mounted on the table 105. If it is desired' to remove the jig from the table 105 between boring operations, the table may have a giude 110 partially surrounding the frame 10 in order that such frame may always be positioned in the same place on the table 105;

In-operation of the device, the two cradles 30 and 60 are brought to-their zero or level positions in which both: cradles 30 and 60 are upright when the lower surface of the base 10 is horizontal and in which the index points 46 and 70 are at the zero positions on their scales 44 and 68, respectively. The bowling ball 82 is then placed: in. the cradle 60 and clamped in position by the plate: 88 and thumb nut 102. New bowling balls contain mark*: ings thereon indicating a central point about which the; finger holes should-be bored as well as the direction-in’which-the ball should roll for best: balance. The central· point of the ball, referred to, is positioned directly below the drill 108: when the cradles 30 and 60 are in zero position. The two cradles are then pivoted about theiraxes to set the sacles 44 and 48 relative to the index points-’ 40 and 70, respectively, for a finger hole to be bored in accordance with data obtained from a finger hole positioning', device of the type mentioned above. The cradles -are: then clamped imposition by the thumb nuts'56 and 80 and a hole bored with the proper size drill to theproper depth. This operation is repeated for each hole to be; bored. The jig may be employed to bore finger holes; for bowlers who use- either the right or left hand, or one or two:fingers in addition to the thumb. For a right handed bowler using the thumb and the second and third: fingers, the position and angle of the hole 112 for the thumb is indicated in dotted lines in the diagrammatic: elevations of the ball in Figs. 4 and 5. The holes 114 and 116 for the second and third finger are similarly indicated: in dotted lines, the position: of the various holes in the surface of the ball being shown by circles in the diagrammatic plan view of the ball in Fig. 7.

It will be noted from Fig. 5 that the central axes lir,'.' 75 114' and 116’, respectively, of the holes 112, 114 arid'

2,879, 5

116 pass through the central axis 59' of the ball, which axis 59' corresponds to the axis through the pivot members 59 of Figs. 1 and 2. The central axes of the holes also pass through points 118, 120 and 122, respectively, in a great circle of the ball perpendicular to the axis 59' 5 of Fig. 5, such great circle being the same as the outline 82' of the ball in Fig. 5. The points 118, 120 and 122 are approximately diametrically opposite their respective holes 112, 114 and 116. The axis of the pivot members 22 passes through such points respectively and is tangent 10 to the great circle just mentioned when the jig is positioned to bore each of the holes 112, 114 and 116. It will be apparent that in the jig of the present invention, the angles of the holes relative to the axes of the ball are determined by the jig itself when the location of the 15 holes on the surface of the ball are determined and set on the scales 44 and 68 of Figs. 1 and 2. To set the cradles with reference to the scales 44 and 68, it is necessary to know the distances G, Η, I, J and K of Fig. 7. Such distances are measured along great circles of the 20 ball at right angles to each other, one of such great circles being through the dotted line 126 containing the arrow 128 and this being the same great circle containing the points 118,120 and 122 of Fig. 5.

. The data for determining the distances G to K inclu- 25 sive of Fig. 7 is obtained by the finger hole position determining device of the copending application, referred to above. Such device contains finger receiving elements and such elements have upper end portions terminating substantially in a spherical surface corresponding to that of a bowling ball and the upper ends of such finger receiving elements 130, 132 and 134 for the thumb, second finger and third finger of the right hand of a bowler are diagrammatically shown in Fig. 6. The finger receiving elements are each pivoted about two different axes. One of such pivotal axes corresponds to the axis 59' of Figs. 4 and 5. The other pivotal axes for the thumb receiving element 130 and finger receiving elements 132 arid 134 for the second and third fingers are approximately tangent to the great circle of Fig. 5 at the points 118, 120 and 122, respectively. The thumb receiving element has a rear wall 136 and a side wall 138 providing thumb engaging surfaces at right angles to each other and parallel to the central axis 112' (Fig. 5) of the thumb hole 112 to be bored, the outline of the thumb being indicated by the circle 140 of Fig. 6. The finger receiving element 132 has a front wall 142 and a side wall 144 providing finger engaging surfaces at right angles to each other and parallel to the axis 114' of the finger hole 114 to be bored for the second finger, the outline of such second finger being indicated by the circle 146 of Fig. 6. Similarly, the finger receiving element 134 has a front wall 148 and a side wall 150 providing finger engaging surfaces at right angles to each other and parallel to the axis 116' of the finger hole 116 to be bored for the third finger, the outline of such third finger being indicated by the circle 152 of Fig. 6. The sizes of the holes to be bored for the thumb and fingers are first determined by known types of finger gages and the radiuses of such holes recorded. The circles 140, 146 and 152 are also intended to represent the size of the holes for the thumb and fingers as determined by such gages.·

The arrow 128 of Fig. 6 corresponds to the arrow 128 of Fig. 7 and the finger receiving element 132 for the second finger is first aligned with such arrow so that the distance A of Fig. 6 measured laterally between such arrow and the finger engaging surface of the side wall 144 of such finger receiving element is equal to the radius of the hole to be bored for the second finger. The hand of the bowler is then positioned with the thumb and second and third fingers in the corresponding finger receiving elements and with the forearm aligned with the arrow 128, the various finger receiving elements being adjusted about their two pivotal axis until a comfortable

679 fit is obtained with the thumb-and fingers of the bowler in engagement with the finger engaging surfaces of the finger receiving elements. In Fig. 4, the solid line 138' corresponds to the thumb engaging surface of the side wall 138 of the thumb receiving element 130, the solid line 144' corresponds to the finger engaging surface of the side wall 144 of the finger receiving element 132 and the solid line 150' corresponds to the finger engaging surface of the side wall 150 of the finger receiving element 134. Similarly in Fig. 5, the solid line 136' corresponds to the thumb receiving surface of the rear wall 136 of the thumb receiving element 130, the solid line 142' corresponds to the finger engaging surface of the side wall 142 of the finger receiving element 132 and the solid line 148' corresponds to the finger engaging surface of the side wall 148 of the finger receiving element 134.

As stated above, the distance A of Fig. 6 is set and maintained equal to the radius of the hole to be bored for the second finger, which is the radius of the circle 146. The distance B is the distance in a direction opposite the arrow 128 between the finger engaging surface of the front wall 142 of the finger receiving element 132 and finger engaging surface of the front wall 148 of the finger receiving element 134, such surface of the finger receiving element 134 for the third finger always being set and maintained at a zero position corresponding to an arbitrary base line 154 so far as motion of such element parallel to the arrow 128 is concerned. The dis³⁰ tance C is the lateral distance between the finger engaging surface of the side wall 150 of the finger receiving element 132 and the arrow 128. Distance D is the distance in the direction of the arrow 128 between' the finger engaging surface of the rear wall 136 of the thumb 25 receiving element 130 and another arbitrary base line 156. The distance E is the lateral distance between the arrow 128 and the finger engaging surface of the side wall 138 of the thumb receiving element 130. The distance F is the distance between the base line 154 and the base line 156. This distance is an arbitrary design factor in each gauge for determining the position of finger holes and is known for each such gauge.

In the diagrammatic plan view of the upper portion of the bowling ball of Fig. 7 with the holes 112, 114 and 45 116 drilled therein, the distance G is measured in a direction opposite to that of the arrow 128 from the zero' point of the ball referred to above and is equal to one half of the distance between the centers of the circles 146 and 140 of Fig. 6 measured in the direction of the 50 arrow 128. This distance is determined by taking one. half of the sum found by adding the distances B, D and F of Fig. 6 and the radiuses of the circles 140 and 146 of Fig. 6. In setting the jig of the present invention to bore the hole 114, the cradle 30 is maintained in its 55 zero position as the hole 114 is always centered with respect to the arrow 128. The cradle 60 is pivoted forwardly to set the distance G on the scale 68 and the hole 114 is then drilled by employing the correct size drill 108 for the hole for the second finger. To drill the 60 hole 112 for the thumb, the cradle 60 is then pivoted rearwardly to set the distance H on the scale 68. This distance is always made equal to the distance G. The cradle 30 is then pivoted to set the distance I on the scale 44. This distance is determined by adding the radius ³³ of the circle 140 of Fig. 6 to the distance E of such figure. The hole 112 is then bored with the proper sized drill for the thumb hole 112. To drill the hole 116, the cradle 60 is pivoted forwardly to set the distance J on the scale 68. The distance J is equal to the distance G of Fig. 7 minus the distance B of Fig. 6 minus the radius of circle 146 of Fig. 6 plus the radius of circle 152 of Fig. 6. The cradle 30 is then pivoted to the left to set the distance K on the scale 44. The distance K 75 is equal to the distance C of Fig. 6 plus the radius of

2,879,679 circle 152. The hole 116 is then bored with a proper sized drill for the third finger of the bowler’s right hand. The distances G, Η, I, J, and K of Fig. 7 thus locate the centers of the holes 112, 114 and 116 on the outer surface of the bowling ball, it being understood that these distances are measured on great circles of the ball at right angles to each other. The holes may be bored in any desired order and for bowlers using the left hand or a different number of fingers and in all cases, the positions of the pivotal axes of the cradles 30 and 60 predetermine the correct angles for the various finger receiving holes.

While I have described the preferred embodiment of my invention, it is to be understood that the details thereof may be varied and that the scope of the invention is to be determined by the following claims.