US 2652254 A
Description (OCR text may contain errors)
Sept. l5, 1953 R. M. VERBURG 2,652,254
GOLF BALL Filed OCT.. l14, 1948 INVENTOR. Robert M, Verburg ATTOHNYS Patented Sept. 15, 1953 GOLF BALL Robert M. Verburg,
N. J., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application October 14, 1948, Serial No. 54,418
3 Claims. l
The present invention relates to game balls, more particularly to the provision of a new core therein. It has special reference to the construction of golf balls, although it is also useful in the manufacture: of similar game balls such as baseballs Golf balls have been made for many years with a semi-hard rubber core about which is wound a tensioned body of rubber thread to build up the ball body which is thereafter encased in an outer covering of rubber.
In recent years liquid cores have come into use, being employed for the construction of the harder golf ball, designed for longer flight and having a highly tensed winding of rubber thread The liquid core, which customarily is composed of an elastic envelope iilled with a suitable liquid, is superior to the semihard rubber ocre for this harder construction, due to its capacity to extensively deform under impact and thereby ai'lord a greater measure of protection to the highly tensed elastic Winding. It has the disadvantagey however, of slower recovery after deformation than the semi-solid rubber core with resulting increased lag in restoration of the original center of gravity of the golf ball.
It is the principal object of this invention to provide in game balls, more especially in golf balls, a soft core of simple construction which` has the capacity to extensively deform` under impact but which has a faster rate of recovery after deformation than the liquid core.
The foregoing and ancillary objects which will become apparent as the description proceeds can be accomplished in accordance with my invention by employing as the material for the core, a highly viscous vinyl alkyl ether polymer which has substantial cold ilow at ordinary temperatures.
The aforedened polymers useful as core material in the game balls of the present invention. vary in consistency from balsem-like bodies of lower viscosity to inherently resilient putty-like bodies of higher viscosity and offer accordingly a rather wide choice in selection of material for the core. A recommended general group of the polymers are those having a specilic viscosity ranging from about 0.2 to 0.9. Preferred from the standpoint of serving as the core material in golf balls and in other game balls requiring a high degree of resilience, are the polymers having a specic viscosity in the upper range, namely, from about 0.5 to 0.9, which polymers possess inherent resilience. The polymers can be obtained by polymerizing in known Way, vinyl alkyl ether monomers such as, vinyl methyl ether, vinyl ethyl ether, vinyl isopropyl ether, vinyl n-butyl ether,vinyl iscbutyl ether, mixtures of one or more of these monomers with each other and with other polymerizable vinyl compounds Where the latter is used in minor amounts which are insuflicient to change the character of the polymers from those of highly viscous bodies having substantial cold flow at ordinary temperatures.
The specic viscosity as used herein with reference to the polymers is determined in an Ostwald-Fenske viscometer at 25 C. on a one gram sample: of the polymer dissolved in milliliters of benzene.
With 4the exception of the material forming the core, the game balls of the invention. can be made in accordance with the usual practice both as to materials and construction. The core may be fashioned from the polymer in any way found suitable. It can` be formed by cold molding the polymer previously chilled to a solid condition. The formed core is maintained in the chilled solid condition for and during the winding operation which is performed with tension on the flexible winding as desired. On subs..- quent thawing, the original consistency of the core is restored. The outer cover may be applied to the ball body in the usual fashion.
The various features of the invention will be more fully understood by reference to the accompanying drawing which is a partly sectional view of a golf ball embodying the invention.
As shown in` the single ligure of the drawing, the golf ball is made up of a soft core i composed of polymerlzed vinyl methyl ether of specinc viscosity 0.5, which is highly viscous and has substantial cold ow at ordinary temperatures, and a body of rubber thread, tape or other elastic winding 2 wound tightly about the core. The core may be of the same size as the semihard rubber core heretofore used. The ball body formed of the core and elastic winding is encased in an outer covering 3, suitably balata, molded thereabout.
While the invention has been described with particular reference to the manufacture of golf balls, it will be readily understood that it is not restricted thereto but may be employed, in the manufacture of other game balls, such as, for example, baseballs, wherein yarn rather than rubber thread is Wound under tension about the core.
Since various embodiments of the invention as a fraction, called the specic viscosity nsp according to -EL- Y Sp- 770 ijf. v :I where m is termed the relative viscosityaildfis equalto A .f
The specic viscosity is dependent on the conc1i'txj`ation;r and in order to define aquantity characteristic of a given 'macromolecule in a solvent "it is necessary to take lim -I claimt 1.. A golf ball having a soft core consisting of a the initial'slope of `the 15p versus concentration curve, i'. e.
4 polymerized vinyl alkyl ether of specific viscosity from about 0.5 to 0.9 and a body of elastic thread Wound tightly about the core.
2. A golf ball having a soft core consisting of polymerized Vinyl methyl ether of specific viscosity from about 0.5 to 0.9 and a body of elastic thread wound tightly about the core.
' 3'; A golf `ball having a soft core consisting of a polymerized vinyl alkyl ether of specic viscosity from about 0.2 to 0.9 and a body of elastic thread wound tightly about the core.
ROBERT M. VERBURG.
References Cited in the le of this patent UNITED-STATES PATENTS OTHER `REFFEREYCES The Amazing'NeW Chemical Family, OctoberV 6, 1945; The Oil and Gas Journal.
Chemical Engineers Handbook, 2nd edition, 1941, pages '788 and`789.
. Great Brit-.ain July 19, 1943*