US 2741480 A
Description (OCR text may contain errors)
R. F. SMlTH April 10, 1956 GOLF BALL Filed Feb. 4. 1953 OOOQ OOOQ QQ QQ OOOOQ 00000000 W W mE ww U A 2 ma United States GOLF BALL The invention relates to golf balls and more particularly to a golf ball construction which is perfectly balanced, and has a substantially greater than usual concentration of weight in its center element, producing truer and longer flight with better control, greater accuracy and distance,
and greater putting accuracy because of truer, straighter rolling, and which is more uniform in performance not only as to individual balls but as to groups of balls because of identical characteristics throughout.
1 have discovered that the relative weight distribution of the components or elements of a golf ball has an important bearing on the controllability of the ball in flight and in putting, as to distance and accuracy. Where a substantially greater than usual weight with respect to the volume occupied thereby is concentrated in the center element of a golf ball, there is less opportunity for minute weight variations or eccentricity in the outer regions of the ball to affect the accuracy of the ball in flight and in putting.
Moreover, when a greater weight to volume ratio is established in the center element of a golf ball, more ball volume is available for the thread winding. When more threads are present in a golf ball, while retaining center resilience, the over-all resilience and life of the ball is increased.
In addition to the discovery that the use of a greater weight to volume ratio in the center of the golf ball gives an astounding increase in the accuracy and controllability of a ball, I have discovered further that if the golf ball cover element has a lighter weight, and is made of a material having the same specific gravity as the threads, and is not painted, an eccentricity of weight distribution in the outer regions of the ball is completely eliminated so that each ball is perfectly balanced and any number of balls constructed in the same manner are uniform and identical from ball to ball. This enables a player to attain and maintain greater control and accuracy throughout a game where it is necessary to use a series of balls during the course of a game.
The importance of the weight characteristics of the cover material cannot be underestimated. In the first place, if the cover material has a lower specific gravity than the usual balata or gutta percha material used for golf ball covers, variations in cover thickness produces less eflective Weight eccentricity in the ball. In the second place, if the cover material has the same specific gravity as the pure rubber thread winding, variations in cover thickness do not produce weight eccentricity in the outer regions of the ball provided that the ball has a truly spherical nominal outer surface, determined by the precision of the dies in which the ball is molded.
The elimination of painting is equally important in providing for perfect ball balance, because it is impossible as a practical matter, to applytwo or three coats atent of paint to the cover, as is usual in prior golf ball manufacture, and obtain absolute uniformity in paint thickness over the entire outer surface of a golf ball including the dimple depressions. particularly in the dimples Where such variations always occur, can result in weight eccentricity in an otherwise perfectly balanced ball, which reduces the accuracy of the ball in flight and in putting.
Finally, the elimination of paint from the surface of a golf ball enables uniformity in dimple shape with sharp corners to be maintained, so that the dimples retain their uniform wind resistance thereby keeping the ball from skidding or dipping in flight.
When a golf ball is painted, in addition to the nonuniformity of paint thickness, particularly in the dimples, the intersection of the dimple surfaces with the outer spherical ball surface is not sharp but rounded, which reduces the uniformity of wind resistance of the ball in flight.
Accordingly, it is an object of the present invention to provide a new golf ball construction resulting in a perfectly balanced ball.
Furthermore, it'is an object of the present invention to provide a new golf ball construction with which better control, and greater accuracy and distance can be obtained in use.
Also, it is an object of the present invention to provide a new golf ball construction which in use has a truer and longer flight and rolls truer and straighter in putting.
Also, it is an object of the present invention to provide a new golf ball construction having a substantially increased weight to volume ratio in the ball center.
Moreover, it is an object of the present invention to provide a new golf ball construction in which the thread winding and cover materials have the same specific gravity, thereby eliminating weight distribution variations which occur where the specific gravities of the thread Winding and cover materials are not the sa he and where there are variations in the thicknesses of the two materials.
Moreover, it is an object of the present inventionto provide a new white covered golf ballconstruction in which cover painting is eliminated thereby eliminating weight eccentricity in the outer regions of the ball.
Moreover, it is an object of the present invention to provide a new golf ball construction in which precision molded dimple and spherical outer surfaces with sharp intersecting corners are maintained in the finished ball to maintain uniformity in dimple wind resistance in flight.
Also, it is an object of the present invention to provide a new golf ball construction in which extreme accuracy in size, weight, surface and concentricity of the ball and its elements is obtained giving the highest degree of uniformity in flight characteristics, controllability and performance for any individual ball or for all balls in a group intended to be similar or the same,
Also, it is an object of the present invention to provide a new golf ball construction incorporating all of the foregoing characteristics, and in which complete and absolute uniformity may be maintained in manufacture so that all balls are the same with like characteristics.
Moreover, it is object of the present invention to provide a new golf ball construction which has combined characteristics of uniform performance, greater durability, greater concentricity, and greater controllability with perfect balance resulting in use in greater control, accuracy and distance.
Finally, it is an object of the present invention to provide a new golf ball construction incorporating the fore- Thus, variations in paint thickness,
going desiderata, which may be manufactured with ease,
which satisfactorily solves the complicated problems and the described difiiculties overcome, by the improvements,
elements, combinations, arrangements, constructions, relationships, ratios and parts which comprise the present in vention, the nature of which is set forth in the following general statement, a preferred embodiment of which illustrative of the best mode in which applicant has contemplated applying the principlesis set forth in the following description and drawing, and which are particularly and distinctly pointed out and set forth in the appended claims forming part hereof.
The nature of the discoveries and improvements in golf ball construction may be stated in general terms as including in a golf ball, a resilient spherical center element having a diameter preferably not greater than approximately one inch and preferably in the range of from to l", the center having a weight such that its weight to volume ratio as compared with the weight and vol-' ume of'the entire ball is greater than about 1.70, the ball having a rubber thread winding surrounding the resilient center element, and an unpainted cover surrounding the thread winding, the thread winding and cover materials having approximately the same specific gravity, and the ball having a nominal outer diameter not less than 1.68" and a weight not greater than 1.62 oz.
By way of example, a preferred embodiment of the improved golf ball construction is illustrated in the accompanying drawing forming part hereof wherein:
Figure 1 is a side elevation of the improved golf ball with part of the cover broken away;
Fig. 2 is a cross-section through the golf ball illustrated in Fig. l; and
Fig. 3 is an enlarged fragmentary sectional view of a portion of Fig. 2.
Similar numerals refer to similar parts throughout the various figures of the drawings.
Under established ofiicial golf rules, a golf ball must.
have a nominal outer diameter of its outer spherical surface not less than 1.68" and a weight not greater than 1.62 oz.; and whenever a golf ball is referred to herein it is intended that the ball shall comply with these size and weight requirements. The improved golf ball is illustrated generally at 1 and includes a center element 2, thread windings 3, and a cover 4 provided with the usual dimples 5.
In accordance with the present invention, the center 2 V is made of a usual rubber compound including vulcanizing chemicals and some heavy material such as powdered zinc to increase the weight thereof while retaining resilience. The size or volume and weight of the center 2, and the relationship between the same, in order to obtain the new results of the present invention, should conform to the values or ranges stated in detail below.
The thread winding 3 is composed of the usual pure rubber thread material used in the construction of golf balls, and is wrapped or wound about the center 2 under uniform tension. The specific gravity of such rubber thread winding, taking into consideration the voids which occur at the interstices between the different convolutions of the rubber thread, is approximately 0.94.
7 throughout, its specific gravity shall be equal to the specific V gravity of the thread winding; that is 0.94.
I have found that a polyethylene plastic, which becomes liquid at a temperature of from 475 to 550 F. and which in the pure state without coloring has a specific gravity of 0.92 at 20 C., has physical properties closely approaching those of balata and gutta percha in respect to resiliency and toughness. Such plastic material is receptive to white coloring material such that when colored it has a specific gravity of 0.94. Therefore, it is preferred to form the golf ball cover 4 of such polyethylene plastic material, although other plastic ma terials having similar characteristics with respect to resiliency, toughness and specific gravity may be used in place of a polyethylene plastic.
The polyethylene plastic material described has a tensile strength of 1800 pounds per square inch with 550% elongation and will not oxidize under normal conditions, or varying conditions of weather and sunlight, and can be molded under pressure with remarkable precision as to Wall thickness; so that, within the limits of precision in the manufacture of dies used to mold the golf balls, a perfect distribution of dimples having uniform depth and size can be formed which will provide extremely uniform wind resistance for the balls in flight.
Further characteristics of the polyethylene plastic material described are that it retains its predetermined physical characteristics indefinitely, and remains unchanged with age. Normally it is not attacked by chemicals, such as may be applied to turf on golf links. It is unaffected by humidity changes or immersion in fresh or salt water, and it does not harden or crack but retains its resilience and toughness for a long period of time.
Furthermore, because white or other coloring material can be combined with the plastic without affecting its physical properties, excepting to raise its specific gravity slightly, the material has a uniform color throughout, which color is retained throughout the life of the ball thereby eliminating the necessity of painting golf balls provided with covers of such plastic material with the resultant elimination of the described difficulties encountered with painted golf balls. Thus, the cover remains white after an extended amount of play and many washings.
The improved golf ball construction, in utilizing cover and thread winding materials having the same specific gravity, avoids difficulties in manufacture because no variations in the ball will occur if in winding the threads 3 on the center 2 the thread wound ball is slightly over or undersized. This lack of variation results because the thickness of the cover wall may become slightly oversized or undersized in molding the finished ball to compensate for the oversize or undersize of the thread wound ball without any variation in the total weight or weight distribution of the threads and cover. 7
Golf balls incorporating the improvements of the pres ent invention may be readily manufactured by forming a molded loaded center elementZ of rubber composition and powdered zinc, and vulcanizing the same by a usual ten minute curing cycle to spherical shape and to the desired size and Weight. The rubber thread material 3 is then wound on the center 2 under uniform high tension to assure perfect balance. The cover material 4 is then applied to a thread wound ball in preformed substantially semi-spherical and substantially uniform thickness blanks and is molded under pressure, at the temperature re quired for molding the particular plastic material involved, in precision dies to form the completed ball and bond the semi-spherical cover blanks together and to the threads as indicated at 6 in Fig. 3.
For the purposes of developing theremarkable characteristics of the present invention in golf ball construction, a center having a 1" diameter is believed to be ideal and an example of such a ball is shown in the following Table A giving diameters, volumes, weights and specific gravities: V
5 6 Table A 1 or 1 5 centers have center weight to volume ratios of 1.36 and 1.38, respectively.
Element Diameter, volume, wt- OZS. Specific Although prior golf balls normally have had center s, Inches 011,111, Gravity either solid or liquid, of a diameter greater than 1 r 5 such as described, a prior solid center golf ball with a Center 1.00 .524 .61 2.01 1" center has heretofore been made as set forth in Table $22192: g 23% :3: D below with a painted balata cover:
hihfiteiiirjjiij: Table D Total Ball 1.68
Element are tee-ts Center s of total- Center L J24 4875 L 61 Center volume= =22.07% of total.
. 37.77 Center weight-volume IQUO=2VTZ=L7L The ball of Table A is representative of the golf ball Total Ball 1.68 2.483 1.6112 construction of the present invention and has a center weight equal to 37.77% of the total ball Weight and a cen- A875 ter volume equal to 22.07% of the total actual ball volume. Center welght=m=3o'%% of The ratio of center weight percentage to volume percent- 524 H L age is 37.77 to 22.07, or 1.71, hereinafter termed the cen- Cent" 2.381 ter Weight to volume ratio. Further, it should be under- 25 ,2 stood that when the term weight to volume ratio is used Center weigntfi'omme 22.00 in the claims, it refers to the foregoing ratio of center Weight percentage to volume percentage. Thus, a direct comparison can be made between the A second example of a ball involving the construction balls of Tables A and herein the ball of Table A and characteristics of the present invention is given in 30 has a substantiall' greater center Weight to volume ratio, Table B below for a ball with a /t center: which, along with the threads and cover of the same specific gravity, provide the improved characteristics described. Table B Although the improved golf ball construction of the present invention has been illustrated and described using Element Diameter, Volume, Wt. 0Z5 Specific a sohd center 2, a liquid center may be used instead, the Inches m Gl'avlty rubber portion of Wl'llCll will be more heavily loaded with powdered zinc or other weight increasing material, while :33;; :32 retaining resiliency, to provide a liquid center having 1.68 .508 .2755 .94 A0 :veijght 2nd sir; characteristics similar to those given in r e la es 1 and 1%if1i3ie i:::::::::::::::::::::::::::: :?63 :::::::::::::::t:::: Although the anathickness of the improved golf TomlBan L68 483 149 ball construction is approximately the same as the cover thickness of typical prior art golf balls, nevertheless the 4456 thread thickness or voiurne is greater. This characteristic Center Weight= =27.59% ol'total. 49 grvesgreater hie and res lience to the ball since ordinarily 201 the life of a golf ball is dependent upon the character Center volume= =9.31% oitctal. and amount of pure rubber thread Winding therein, assuming that center resilience has been maintained, became! Weishtv0111memti0= cause the more threads there are in a ball the better the 50 ball from the standpoint of over-all resilience and life. A yp solid center ball made in accordance with Accordingly, the present invention provides a new golf Prior PTaCtice and having a Painted balata Cove! With a ball construction having perfect balance, and having a Solid center is Set forth in Table C belQW and has concentration of weight in its lively center resulting in ima Center Weightto Volume Tam? of 13-01 proved controllability and greater accuracy and distance in flight, and greater accurac and trueness in putting,
While presenting uniform wind resistance from precision molded spherical and dimple exterior surfaces; provides Element Diameter, Volume, Wt 025 p i a new golf ball construction incorporating the foregoing Inches On. In. Gravity arrangements, relationship-s, ratios and characteristics ac- 69 complishing the described new results, avoiding difliculties,
and eliminating longstanding problems in the art; and provides a golf ball construction which may be fabricated readily in a simple, effective and inexpensive manner.
In the foregoing description, certain terms have been used for brevity, clearnss and understanding; but no un- Table C Center Tom! B511 L68 2-433 1-6195 necessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are m-i 1 a Center weight: .eo2 of total used for descriptive purposes erein and not for the pur 1.6190 pose 01 limitation, and are intended to be broadly con- Center v0lume= =s0.s7% of total. 70 smled' n 15 Moreover, the embodiment or the improved construc- Center weighFvolume gg-g tron illustrated and descnoed and the examples given are by way of example, and the scope of the present inven- Typical liquid center balls constructed in accordance tion is not limited to the exact details of construction of with prior practice having painted balata covers and the various parts.
Having now described the features, discoveries and principles of the invention, the manufacture and examples of preferred embodiments thereof, and the advantageous, new and useful results obtained thereby; the new and useful improvements, elements, combinations, arrangements, constructions, relationships, ratios, and parts, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.
1. In golf ball construction, a resilient center element, the center element having a diameter not greater than 1 and a weight to volume ratio with respect to the ball in excess of about 1.70, the ball having a nominal outer diameter of at least 1.68 and a total weight of not more than 1.62 025., the ball having a natural rubber thread winding and an unpainted cover having a thickness of about 0.075", and the thread winding and cover materials having the same specific gravity of about 0.94.
2. The golf ball construction defined in claim 1, in
which the diameter of the resilient center element is within the range of l" to A".
3. The golf ball construction defined in claim 1, in which the resilient center element is solid, is formed of a rubber composition, and has a diameter Within the range of 1" to A".
4. The golf ball construction defined in claim 1, in which the center weight to volume ratio is between 1.71 and 2.96.
5. The golf ball construction defined in claim 1, in which the center element is solid, has a 1" diameter, comprises rubber composition loaded With powdered zinc, and has a center Weight to volume ratio of 1.71; and in which the cover material comprises colored polyethylene plastic material; 7
6. The golf ball construction defined in claim 1, in which the center element is solid, has a diameter of A, comprises rubber composition loaded with a powdered zinc, and has a center weight to volume ratio of 2.96; and in which the cover material comprises colored polyethylene plastic material.
References Cited in the file of this patent UNITED STATES :PATENTS 1,395,413 Hoffman et a1 Nov. 1, 1921 2,259,060 Brown Oct. 14, 1941 2,261,760 Habgood Nov. 4, 1941 2,264,604 Young Dec. 2, 1941