US 2229170 A
Description (OCR text may contain errors)
Jan. 21, 1941. c, w GREENE 2,229,170
GOLF BALL Filed Aug. 5, 1958 ,FIET.
I 3&WMVDOO Mar/es W 6/66/76 Patented Jan. 21, 1941 UNITED STATES PATENT OFFICE De Vilbiss Company, tion of Ohio Application August 5,
This invention relates to golf balls, and particularly to the core member thereof.
It has been customary in the manufacture of golf balls to provide a suitable core, usually of shell form, filled with a suitable liquid substance. A common procedure for filling the core with the liquid is to use a hypodermic needle by which the wall of the core shell is punctured and the liquid injected therethrough, provision being made during injection for the escape of air and surplus filler therefrom. Another method is to force the liquid into the core shell from a nozzle through a pre-formed hole in its wall. In either case the practice usually followed is to seal the puncture or hole after filling by the application of a rubber patch to the outer peripheral surface of the core and over the hole or puncture. This patch is objectionable as it forms a slight bulge on the surface of the core which destroys its uniform spherical shape and produces an unbalanced action of the ball by adding weight to one side.
Another objection incident to the present methods of manufacturing golf balls having filled cores is that the core wall is invariably of uneven thickness and the specific gravity of the filling liquid is different from that of the core material, thus causing the center of gravity of the core to shift in accordance with the unevenness of the wall thickness and effecting an unbalanced condition of the golf ball.
Another objection incident to the present methods of manufacturing golf balls having filled cores with smooth exterior surfaces is the difficulty encountered in applying the wound rubber section thereto in a uniform manner both as to tension and winding, so that the completed ball will be perfectly balanced. In this winding operation, the present practice, so far as I am aware, is to wind a rubber thread or ribbon under predetermined tension uniformly about the smooth surface of the core. In such winding some slippage of the rubber on the smooth core occurs, which not only prevents uniform winding, but causes a variance in the winding tension. Both of these features are undesirable as they cause an unbalanced condition in the ball, so it will not follow a straight course in flight or rolling.
An object of the invention is the application of patches to the liquid filled core members of golf balls in a manner to prevent an unbalanced condition of the ball.
Another object of the invention is to prevent the unbalanced condition of a golf ball due to unevenness of the core wall thickness by fillin Toledo, Ohio, a corpora- 1938, Serial No. 223,263
the core with a liquid or material of the same specific gravity as that of the core material.
Another object is the provision in golf balls of a core member having a surface of such character that a rubber thread or ribbon may be I wound under tension thereon without slipping or offsetting resulting in an unbalanced condition of the golf ball.
The invention is fully described in the following specification, and a preferred embodiment thereof is illustrated in the accompanying drawing, in which Figure 1 is a central diagrammatic section of a golf ball embodying the invention with the core in full; Fig. 2 is an enlarged fragmentary section of a portion of the core member showing the surface depression through which the core may be punctured for filling; Fig. 3 is a fragmentary external View of such portion of the core with a patch member for filling the surface recess in spaced relation thereto; Fig. 4 is a central sectional view of the core showing a filler-injecting needle inserted through the bottom of the core depression, with the parts exaggerated, and Fig. 5 is a view similar to Fig. 2 with a patch mounted in and filling the surface depression in sealing relation to the filling puncture.
Referring to the drawing, I designates a golf ball having a hollow rubber core 2 filled with a suitable liquid 3, which may be molasses. This core is wound with a rubber thread or ribbon under tension to form an intermediate rubber section 4, and such section is enclosed in an outer shell 5, as well understood in theart.
The core 2 may have a hole through its wall through which the filling liquid may be introduced or it may have its wall punctured by a needle of the hypodermic type, such as shown at 6 in Fig. 4, and the liquid injected into the core through such needle. A vent tube 1 is shown on the side of the needle. Both methods of filling are common.
One feature of the invention resides in forming the outer peripheral surface of the core 2, where the filler hole is provided or the puncture is to be made, with a recess 8, preferably circular in form and of uniform depth, so that the core wall at the filling point is thinner than the adjoining wall portions. When the core has been filled, the hole or puncture is hermetically sealed by a patch 9. This patch is of a size and shape to perfectly fit and fill the recess 8 and is of a thickness for its outer surface to register with and form a perfect continuation of the ball periphery. The patch corresponds in weight to the surface portion omitted by the formation of the recess. The mounting of this patch in the recess produces a perfectly balanced core when properly filled, as in accordance with established practice. While the patch is preferably of the same material as the core, it may be of a plastic nature.
To facilitate winding of rubber thread or ribbon on the core 2 without slipping to form the portion 4, in which another feature of the invention resides, the core is provided over its entire surface, preferably including the outer surface of the patch, with small teats or projections l0. These projections are of uniform size and are distributed in such manner as not to interfere with the perfect balance of the core and of a golf ball including the same.
The projections [0 provide holding or anchoring means for the thread or ribbon wound on the core and prevent any slippage or lateral movement of the thread or ribbon from true winding position. The cores are usually wound by machine with the rubber thread or ribbon under tension and slippage frequently occurs even when extreme care is exercised in the winding. The roughening of the core in this manner, in addition to preventing slippage of the winding material thereon, also avoids slippage between the core and the elements of the winding machine by which it is turned.
When winding the core with a ribbon-like thread, it is important to make the projections l0 small, shallow and semi-spherical, so that the ribbon may be wound thereover as well as therebetween and will not be doubled or folded transversely on itself by entering a space between projections, which space is of less width than the ribbon. This is an important feature in maintaining a truly balanced ball with its center of gravity at the center of the sphere.
The hollow core members 2 of golf balls are molded from rubber and the wall thereof is necessarily of uneven thickness, as illustrated in Fig. 4, This condition shifts the center of gravity of the core a greater or less extent, as is apparent. In order that the filling liquid or material 3 may correct this condition, it should have a specific gravity the same as that of the material forming the core member 2, which is preferably 1.64.
A filling liquid suitable for this purpose and which is easily varied to change its specific gravity by merely changing the proportion of one of its ingredients without affecting the efficiency of the material comprises the following ingredients in substantially the proportions noted:
Parts Molasses (sp. gr. app. 1.43) 50 Water a 45 Bentonite 5 Blane fixe (in colloidal state) 53 These ingredients are mixed together and ground for several hours in a ball mill. The composition produced has a specific gravity of approximately 1.64 and this is varied one way or the other to exactly equal that of the core member 2 bychanging the amount'of blanc fiXe used.
I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.
Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:
l. A golf ball having a balanced filled core including a hollow spherical rubber member of irregular wall thickness having an outer surface depression to provide for filling of the hollow member through the resultant weakened portion,
a patch material filling said depression to seal the filling opening therein and cooperating with said member to produce a core of true spherical shape, and a material filling said hollow member and being of the same specific gravity as the material of such member, whereby to maintain the center of gravity of the ball irrespective of the irregularity of the wall thickness.
2. A golf ball having a balanced filled core includingahollow spherical rubber member of irregular wall thickness having an outer surface depression to provide for filling of the hollow member through the resultant weakened portion, a patch of the same material as said member filling said depression to seal said hole and cooperating with said member to produce a core of true spherical shape, and a liquid material filling said hollow member and being of the same specific gravity as the material of such member, whereby to maintain the center of gravity of the ball irrespective of the irregularity of the wall thickness.
3. A golf ball having a balanced filled core including a hollow spherical rubber member having its outer surface formed with a depression to provide for filling of the hollow member through the resultant weakened area defined by the depression, and a closure for the opening secured in the depression, said closure in weight equalling that of the material displaced by the formation of the depression whereby to maintain the original weight of the member.
4. A golf ball in accordance with claim 3, wherein the edge of the closure conforms to and abuts the walls defining the depression, and has an outer surface fiush with the original contour of the core and wherein the member and closure are each formed with spaced peripheral projections.
5. A golf ball having a balanced filled core including a hollow spherical rubber member of irregular wall thickness having an outer surface depressionto provide for filling of the member through the resultant weakened portion, a patch material filling said depression to seal the filling opening and cooperating with said member to produce a core of true spherical shape, a material filling said hollow member and being of the same specific gravity as the material of said member,
. said spherical member and the patch material each having a multitude of shallow, integral, projections over its outer surface, and a ribbon-like rubber thread wound uniformly around said member over and between said projections, the space between adjacent projections being at least equal to or greater than the greatest diameter of the thread.
CHARLES W. GREENE.