Duplicator for bowling ball finger and thumb holes

An apparatus, and method, for producing finger and thumb holes in one bowling ball which are identic to those existing in another bowling ball; the essential purpose being to duplicate--in a new bowling ball, for example--the exact size, shape, direction, and span of the finger and thumb holes in an existing, properly hand-fitting, bowling ball.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
While various apparatuses, and methods, are known for the purpose of 
producing custom fitted finger and thumb holes in bowling balls, efforts 
to accurately duplicate the finger and thumb holes existing in one ball in 
another ball (as, for example, by measured, controlled drilling) have not 
met with any substantial acceptance. The present invention was conceived 
in a successful effort to accomplish such duplication. 
2. The Prior Art 
U.S. Pat. Nos. 2,712,160; 2,843,382; 3,386,176; 3,454,440 and 3,858,839 
represent the most relevant prior art known to applicant. 
The above prior art--considered singly or together--does not anticipate, 
nor suggest as obvious, the particular structure of the herein-claimed 
duplicator for bowling ball finger and thumb holes, and applicant has no 
knowledge of any prior art disclosing such particular structure. 
SUMMARY OF THE INVENTION 
The present invention provides, as a major object, an apparatus, and 
method, for producing finger and thumb holes in one bowling ball (as, for 
example, in a new undrilled ball) which are identic to the finger and 
thumb holes existing in another bowling ball (as, for example, a used 
ball). 
The present invention provides, as another important object, an apparatus, 
and method, as above, whose essential purpose is to duplicate in a new 
bowling ball the exact size, shape, direction, and span of the finger and 
thumb holes in an existing, used bowling ball. In this manner, a 
bowler--once one bowling ball is drilled with properly fitting finger and 
thumb holes--can readily obtain another bowling ball with matching finger 
and thumb holes. 
The present invention provides, as a further object, a duplicator for 
bowling ball finger and thumb holes which is designed for ease and economy 
of manufacture. 
The present invention provides, as a still further object, a practical and 
reliable duplicator for bowling ball finger and thumb holes, and one which 
is exceedingly effective for the purpose for which it is designed.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now more particularly to the drawings and to the characters of 
reference marked thereon, the apparatus comprises adjacent but spaced 
rings 1 and 2 of substantial diameter and relatively wide axially; such 
rings being interconnected on opposite sides by parallel tie bars 3 
bolted, as at 4, to, and slot-engaged with, the upper ends of ears 5 
which--in turn--are bolted adjacent their lower ends, as at 6, to the 
corresponding rings. The tie bars 3 are longitudinally slotted, as at 7, 
for reception therethrough of the bolts 4 related to the ring 2; such 
slotting being provided for the purpose of adjustment of the spacing of 
the rings 1 and 2. Also, the bolts 6 permit the rings 1 and 2 to be 
adjusted in their angular relation to each other. 
The rings 1 and 2--after appropriate adjustment of spacing and 
angularity--are seated on the used bowling ball 8 with the ring 1 
symmetrically surrounding the thumb hole 9 and the ring 2 symmetrically 
surrounding the finger holes 10. The rings are chamfered on the lower edge 
for matching engagement with the surface of the ball, as shown at C. 
A longitudinal spanner plate 11 extends generally diametrically across and 
rests on the ring 1 and is located thereon by pins 12 which are engaged 
through selected holes in rows 13 thereof in the end portions of spanner 
plate 11; such rows 13 of holes being parallel to each other and extend 
substantially tangent to the corresponding sides of ring 1, with the pins 
12 engaging in holes 14 in the upper edge portion of said ring at 
diametrically opposed points. 
A core rod 15 depends into the thumb hole 9 from the spanner plate 11; such 
core rod having a head 16 which abuts the spanner plate 11 from beneath 
and is longitudinally adjustably secured thereto by bolts 17 which extend 
through a longitudinal slot 18. By appropriately adjusting the spanner 
plate 11 on ring 1, and adjusting the head 16 on said spanner plate, the 
core rod 15 is set to depend substantially centrally into the thumb hole 
9. See FIG. 4. 
Upon the core rod 15 being so disposed, and after an annular clay dam 19 is 
formed about said thumb hole 9 as an overflow "stop", a fluid--but 
fast-hardening--silicone rubber compound is poured into said thumb hole 9 
whereby there is formed, on core rod 15, a casting 20 having the 
configuration of such thumb hole. The core rod 15 includes projections 21 
which assure against escape of casting 20 from such rod. 
Castings (not shown) are then made of both of the finger holes 10, and this 
is accomplished in substantially the same manner and by like 
instrumentalities as described above relative to the formation of casting 
20. 
More particularly, a pair of side-by-side but spaced, parallel spanner 
plates 22 rest on the ring 2, and at their ends such spanner plates 22 
include rows 23 of holes through selected ones of which pins 24 extend and 
thence engage in pin holes 25 in said ring 2, whereby the spanner plates 
22 are adjusted to lie directly above the corresponding finger holes 10. 
To permit of more universal adjustment of spanner plates 22, the rows 23 
of holes in one plate extend lengthwise thereof, while the rows 23 in the 
other plate extend transversely. 
A core rod 26 depends from each spanner plate 22 substantially centrally 
into the corresponding finger hole 10, and each such core rod 26 includes 
a head 27 adjustably secured to the related spanner plate 22 by bolts 28 
which pass through a longitudinal slot 29 in such spanner plate. 
Thus, with the core rods 26 depending into the finger holes 10, silicone 
rubber castings of said finger holes are formed on the core rods 26 in the 
same fashion that the casting 20 is formed on core rod 15. 
After the three castings have been formed (a thumb hole casting on core rod 
15 and a finger hole casting on each core rod 26), the entire apparatus is 
removed from the used bowling ball 8, and at which time the castings pull 
free from the latter. The castings, however, remain in the exact 
positional relation to each other as existed when formed in the used 
bowling ball; this by reason of the rigid supporting structure provided 
for the respective core rods. 
Nextly, the apparatus is manually disposed in a position overlying the new 
bowling ball 30, and the end positions of the three castings are marked on 
the face of such new ball. At each such marking, a bore is drilled and 
with an inside diameter substantially greater than the outside diameter of 
the corresponding casting. For example, and here by reference to FIG. 5, 
the oversize bore corresponding to the casting 20 is indicated at 31. 
After the three oversize bores are drilled, the apparatus is placed on the 
new ball 30 with the three castings projecting into the related oversize 
bores in substantially centered relation; i.e., with spacing from the 
walls of such oversize bores; the rings 1 and 2 then seating on the new 
ball 30 just as when seated on the used ball 8 for the purpose of 
producing the three castings. 
Thereafter, and here by reference to FIG. 5 as an example, a liquid, 
fast-hardening, epoxy compound--known to the trade as "ball plug" and 
which is normally employed to totally fill holes on bowling balls for 
complete re-drilling--is poured into the oversize bore 31 in the space 
between the thumb hole casting 20 and the oversize bore wall as a filler 
32. Any overflow is contained within a clay dam 33 on the new ball about 
the outer end of each oversize bore. The procedure described immediately 
above is repeated for each of the oversize bores for the finger holes. 
After the filler is introduced, as above, into both the oversize finger and 
thumb holes in the new ball 30 and such filler hardens in each such hole, 
the apparatus is wholly removed from such ball, including withdrawal of 
the three castings; there then remaining in the new ball--and as defined 
by such fillers--finger and thumb holes which are identic to those which 
existed in the used ball 8. Thereafter, and preparatory to use of the new 
ball 30, the clay dam 33 is, of course, removed and the ball ground and 
surface-polished to remove any excess filler which may exist on the ball 
surface about the mouths of the finger and thumb holes. 
If desired, the rows of holes, as indicated at 13 and 23, and the slots 18 
and 29, together with the tie bar slots 7, may have appropriate index 
markings (such as corresponding numerals or letters) associated therewith 
so that a record of the settings of the parts of the apparatus may be 
recorded and later used to re-set said apparatus to again--in still 
another bowling ball--duplicate the finger and thumb holes of the used 
ball which provided the initial castings and which--of necessity in such 
case--be preserved on their core rods for such later use. 
Thus, by a relatively simple apparatus and method of its use, it is 
possible to readily and exactly duplicate in one bowling ball the finger 
and thumb holes of another bowling ball. 
From the foregoing description, it will be readily seen that there has been 
produced such a duplicator for bowling ball finger and thumb holes as 
substantially fulfills the objects of the invention as set forth herein. 
While this specification sets forth in detail the present and preferred 
construction of the duplicator for bowling ball finger and thumb holes, 
still in practice such deviations from such detail may be resorted to as 
do not form a departure from the spirit of the invention as defined by the 
appended claims.