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Publication numberUS3521506 A
Publication typeGrant
Publication dateJul 21, 1970
Filing dateMay 22, 1968
Priority dateMay 22, 1968
Publication numberUS 3521506 A, US 3521506A, US-A-3521506, US3521506 A, US3521506A
InventorsFrank Di Nardo
Original AssigneeFrank Di Nardo
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for forming oblong holes of predetermined orientation in a bowling ball
US 3521506 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

July 21, 1970 F. DI NARDO 3,521,506


METHOD AND APPARATUS FOR FORMING OBLONG HULES OF PRHDETERMINED ORIENTATION IN A BOWLING BALL Filed May 22, 1968 United States Patent 3,521,506 METHOD AND APPARATUS FOR FORMING OBLONG HOLES OF PREDETERMINED ORIENTATION IN A BOWLING BALL Frank Di Nardo, Astoria,N.Y. (51-27 72nd Place, Woodside, N.Y. 11377) Filed May 22, 1968, Ser. No. 731,161 Int. Cl. B23b 41/00, 49/00, 39/26 US. Cl. 77-5 Claims ABSTRACT OF THE DISCLOSURE Producing a specifically located and oriented oblong hole of predetermined size and shape in a bowling ball by superimposing a target with radial lines at predetermined angles, all radiating from a common center on a selected point on a line on the ball, rotating the line on the ball into substantially coincidence with one of the radial lines, making a round hole in the ball, moving the ball a predetermined distance along one of the radial lines, and removing additional material from the side wall of the hole opposite the direction of motion to make the hole oblong.

Apparatus for carrying out the method, including a jig for clamping a bowling ball in a predetermined position, apparatus to superimpose an image having radial lines and a center on a predetermined point on the ball, a drill, means to clamp the ball in a selected orientation on one of the radial lines, means to place the drill in proper position relative to the ball to drill the ball at the predetermined point, and means to move the ball laterally to drill a second hole overlapping the first one.

This invention relates to apparatus for making holes with oblong cross sections at predetermined locations and orientations in bowling balls and to a method for cating, orienting and forming such holes.

The control that a bowler has over a bowling ball is largely dependent on the placement, orientation, and cross-sectional configuration of the holes in the ball. The placement depends upon the structure of he ball, the size of the bowlers hand, and the type of grip he prefers; the orientation depends, at least partly, on the structure of the bowlers fingers; and the cross-sectional configuration depends on the size and shape of his fingers. Balls intended for use by many bowlers may have round holes, but the usual cross section of a human thumb, or at least the end of it with which a bowler grasps the ball, is usually more or less oblong.

In order to fit a bowlers thumb optimally, the thumb hole must not only be oblong with the correct measurements and placed and directed into the ball at the correct angle, but the major axis of the oblong configuration must make the proper angle with respect to a certain part of the structure of the ball. The idea of making oblong thumb holes is not new, but heretofore it has not been possible to orient the major axis at a specified angle.

It is a principal object of the present invention to provide a method and apparatus for producing an oblong thumb hole in a bowling ball with a predetermined angular orientation of the major axis of the oblong cross section. Other objects will become apparent from the following, more detailed, description in connection with the drawings in which:

FIG. 1 shows a bowling ball marked for drilling thumb and finger holes;

FIG. 2 shows an image used in laying out the locations for drilling holes in the ball in FIG. 1; and

FIG. 3 shows a perspective view of the apparatus for drilling the ball of FIG. 1.

Bowling balls are not homogeneous spheres; for better 3,521,506 Patented July 21, 1970 control than would be possible if they were homogeneous, they have weights in certain locations. During manufacture, and as one of the final steps, each ball is marked to indicate its heaviest point. In the ball 11 shown in FIG. 1, this is the point 12, which is within an emblem area 13. The first step in drilling a ball is to draw a line 17 on the surface of the ball through the point 12 and preferably perpendicular to the lines of printing 14 and 16. The thumb hole is drilled on the line 17 at a location .18, and two holes are drilled at locations 19 and 21 for the middle finger and ring finger, respectively. In order to control the ball properly, the distance from the point 12 to the thumbhole location 18 is usually approximately equal to the distance from the point 12 to the location 19 for the middle finger, although for some bowlers these positions may be shifted with respect to the point 12. In the drawing both of these distances are indicated as distance A. The hole locations are laid out for a righthanded bowler and therefore the location 21 for the ring finger is slightly farther from the point 12 than the location 19 for the middle finger.

The locations 19 and 21 are on opposite sides of the line 17, which may be thought of as a meridonal line, or a part of a great circle, on the surface of the ball 11. The center of mass of the ball is thus properly located between the three hole locations 18, 19, and 21.

Upon close examination it may be seen that the hole location 18 indicates two overlapping holes 18a and 18b. When two such holes are formed, the resultant hole in the ball has an oblong shape with a major axis along the line 22. The eccentricity of the oblong hole, which is a measure of the ratio of the narrowest diameter to the widest diameter, must conform to the eccentricity of the bowlers thumb for best control over the ball. It is not difiicult to drill two overlapping holes spaced the proper distance apart to achieve the desired eccentricity but, in addition, the structure of each persons hand has its own unique configuration and one factor is the angle at which the major axis of the oblong hole 18 should lie with respect to the line 17, taking into account the fact that the middle finger and ring finger must fit comfortably into holes at locations 19 and 21. The ball cannot be held in place to drill the hole 18a on the line 17 and then moved perpendicular to the line 17 to drill the hole 18b if the major axis 22 is not perpendicular to the line 17.

Accordingly, the method of this invention includes the step of superimposing an image of a plurality of radial lines as shown in FIG. 2 on the surface of the ball 11 at the proper point. The image in FIG. 2 includes a number of radial lines angularly spaced apart by a predetermined amount, such as 10", from a main line 23. Instead of spacing every one of the lines 10 apart, lines in the fourth quadrant may be spaced 20 apart to make it easier to determine the location of the major axis 22.

As may be seen, all of the lines in the pattern in FIG. 2 radiate from a central point and, in accordance with the method of this invention, the image of this point is placed on the line 17 at the predetermined distance from the point 12. The predetermined distance is equal to the distance A plus approximately one-half the minimum diameter of the thumb hole being formed. The ball is then rotated about an axis through its geometric center and through the center of the image to bring a particular one of the lines in the image corresponding to the major axis 22 into a horizontal position. A first hole 18a is then made at the predetermined pitch angle as determined by techniques that are standard in the bowling industry and then the ball is moved horizontally far enough to permit the second hole 18b to be made, which creates an oblong hole with a major axis along the line 22. Thereafter the edges of the oblong hole are smoothed off and the ball is reoriented to place the line 17 in a perpendicular position and to bring the hole locations 19 and 21 in place to have the holes 19a and 19b for the middle finger and the holes 21a and 21b for the ring finger in position drilled. Frequently it is not necessary to produce oblong holes for the middle finger and rirg finger, and only a single round hole for each of them would then be sufficient. If an oblong hole should be desired for one or both, its major axis may be perpendicular to the line 17 and thus the two holes making up the oblong hole for either the middle finger or the ring finger could be formed by moving the ball 11 laterally from a first position to a second position. However, if desired, an image of a type shown in FIG. 2 may be used to orient the major axis of the holes for the middle finger or the ring finger or both at the proper angle with respect to the line 17, as is done for the thumb hole 18.

FIG. 3 shows apparatus for drilling a bowl ng ball in accordance with the foregoing procedure. The apparatus includes a drilling stand having a base 24, a support cylinder 26 extending vertically therefrom, and a head 27 supported on the cylinder 26 and including a motor connected to rotate a drill bit 28. Mounted on the base 24 is a platform 29 on which a jig 30 comprising a horizontal member 31 and vertical members 32 comprising a horizontal member 31 and vertical member 32 and 33 is slidably positioned. The jig is movable in direction of the arrow 34 and is controlled by a hand wheel 36 to produce what is referred to in the bowling ball art as left and right pitch in the holes drilled in the ball.

The ball to be drilled is indicated by reference numeral 37 and is supported in a cup 38 and held down by a ring 39 under the pressure of a clamp 41. The latter is attached to a pivotally mounted frame 40 comprising two side members 42 and 43 joined together by a member 45. The cup 38 is attached to the member 45, and the Whole frame 40 is pivoted by a lever 44, which is referred to as the span lever. A hand wheel 46 is provided to lock the pivotally mounted frame 40 in any desired position.

The frame 40 is mounted on another frame 48 comprising a pair of side members 49 and 51 joined by a strap 52 across the back. The frame 48 is also pivotally mounted and its position is controlled by a pair of set screws 53 and 54 which are mounted in threaded holes on extensions attached to the side plate 33 to extend over the upper edge of the plate 51 so that the screws 53 and 54 can press against the plate 51 and lock it in any desired position. These screws 53 and 54 control what is referred to as the forward and back pitch of holes drilled in the ball 37.

The present invention includes means to project an optical image on a predetermined point on the surface of the ball 37. The projection means includes a projector 56 having a lens directed at and focused on the surface of the ball 37 when the ball is in the position shown. The projector 56 is mounted on an angular support 58 which in turn is mounted on a vertical post 59 clamped between two opposing members 61 and 62 which are bolted to a guide 63 attached to the base 29. The post 59 is held in place by a pair of thumb screws 64 and 66, which may be easily loosened to permit the post 59 and the projector 56 to be removed when the ball 37 is to be removed.

In order to drill a thumb hole in the ball 37, the ball is first positioned in the cup 38 so that the line 17 is directly beneath the drill bit 28 and in a plane perpendicular to the axis about which the span lever 44 pivots. With the span lever 44 in its forward position, as shown, the optical image of FIG. 2 is focused directly on the point of the line 17 that forms the center of the hole 18a shown in FIG. 1. The ball 37 is then rotated about an axis that includes the geometrical center of the ball and the point on the line 17 that has been selected as the center for the hole 18a until the proper one of the lines of the image in FIG. 2 coincides with the line 17. As may be seen, for a righthanded bowler, the ball is pivoted counterclockwise sufficiently to bring the line 17 into coincidence with one of the radial lines of the image of FIG. 2 which brings the major axis 22 into a transverse plane parallel to the arrow 34. Thereafter the ball 37 is rigidly clamped in place by the bar 41 and the span lever is pushed back to pivot the ball 37 to bring the center of the hole 18a directly under the drill bit 28. The extent of movement of the span lever 44 is set according to the distance between the hole 18a and the center point 12 of the ball as shown in FIG. 1.

After the hole 18a has been drilled, the left and right pitch control wheel 36 is rotated to move the whole jig 30 laterally far enough to permit the hole 18b to be drilled. Because the ball 37 has been rotated a proper number of degrees to bring the major axis 22 into a plane parallel to the direction of the arrow 24, movement of the pitch control wheel 36 is all that is required to drill the second hole 18b at the proper point and at the proper angle with respect to the hole 18b. Actually, the overlap between the holes 18a and 18b is so great that drilling the hole 18b merely amounts to removing material from one part of the side wall formed when the hole 18a is drilled.

After the holes 18a and 18b have been drilled, they may be finished by emery cloth in the usual way. Thereafter the bar 41 is loosened to permit that ball to be moved within the cup 38 and the ball is pivoted to bring the line 17 back into a position where it lies in a plane perpendicular to the axis of the span lever 44. The holes 19a and, if necessary, 19b for the middle finger and holes 21a and, if necessary, 21b can be drilled in accordance with techniques known heretofore, although if the major axis of either must be at an angle other than to the line 17, the optical image in FIG. 2 may be used as was done for the thumb hole.

In the embodiment shown it is necessary to remove the post 59 and the optical projector 56 before the drill is removed, but other drilling machines may be so constructed that the optical projector can remain in place.

What is claimed is:

1. Apparatus for drilling holes in a bowling ball, said apparatus comprising:

(a) a pivotal support for a bowling ball;

(b) means to display a target image having a plurality of substantially radial lines and a center to a selected spot on said ball;

(0) means to clamp said ball to said support in any desired orientation with respect to said target;

(d) a drill bit;

(e) means to drive said bit into said ball along a predetermined path centered on said selected spot; and

(f) means to effect relative movement between said support and said bit to a predetermined extent along a predetermined line, whereby a successive operation of said bit will produce an oblong hole in said ball with a major axis of said hole on said predetermined line.

2. The apparatus of claim 1 in which:

(a) said means to display said image comprises an optical projector.

3. The apparatus of claim 2 in which:

(a) said apparatus comprises a fixed base for said support; and

(b) second clamping means to clamp said projector rigidly to said fixed base.

4. The apparatus of claim 2 in which:

(a) said projector is directed at a predetermined point in space; and

(b) said pivotal support pivots said ball to rotate said selected spot from said point in space to a position aligned with the center of said bit.

5. The method of drilling an oblong hole having a major axis intercepting a predetermined line on the surface of a bowling ball at a predetermined point and a predetermined angle, said method comprising the steps of:

(a) forming on said point an image comprising substantially radial lines and a center;

(b) orienting said point so that said center falls on said References Cited point and a selected one of said substantially radial UNITED STATES PATENTS lines makes said predetermined angle with respect to said predetermined line; 2087321 7/1937 Hflke (c) making a hole in said ball in a predetermined di- 2269946 1/1942 Langerection through said point; 5 FOREIGN PATENTS (d) moving said ball a predetermined distance along 1,165,464 3/1964 Germany.

sald selected hue; and

FRANCIS S. HUSAR, Primary Examiner ge) removing additional material forming one S1-d6 of said hole to form a hole of substantially oblong cross- 10 mg 1 section. 77-62; 353-40

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2087321 *Apr 1, 1935Jul 20, 1937Hilke Henry CSplitting machine
US2269946 *Apr 20, 1940Jan 13, 1942Raybestos Manhattan IncWork holder for drilling bowling balls
DE1165464B *Dec 10, 1956Mar 12, 1964Dresden FeinmessGraviergeraet fuer die Kartenoriginalherstellung nach dem Schichtgravurverfahren
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3805394 *Mar 22, 1972Apr 23, 1974B MarbergHole pitch indicator for drilling bowling ball
US5173016 *Apr 17, 1991Dec 22, 1992Pro Shops UnlimitedApparatus and method for forming finger and thumb holes in bowling balls
US5409334 *Aug 26, 1994Apr 25, 1995David EdisVacuum vice for bowling balls
US5427478 *Sep 30, 1993Jun 27, 1995John N. BoucherBowling ball drilling apparatus
US5624215 *Jun 26, 1995Apr 29, 1997Boucher; John N.Bowling ball drilling
US5634749 *Oct 21, 1994Jun 3, 1997Jerry LiemVacuum vice for bowling balls
U.S. Classification409/85, 408/DIG.100, 353/40, 408/16, 409/97
International ClassificationB23B39/14, B23Q1/48
Cooperative ClassificationY10S408/01, B23B39/14, B23Q1/48
European ClassificationB23Q1/48, B23B39/14