Play ball and method in making the same

May 15, 1945.

G. S. RADFORD

2,376,084

PLAY BALL AND METHODS IN MAKING THE SAME

Filed Nov. 22, 1940

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Patented May 15, 1945

2,376,084

UNITED STATES PATENT OFFICE

2,376,084

PLAY BALL AND METHOD IN MAKING

THE SAME

George S. Radford, Norwalk, Conn., assignor to

A. G. Spalding &amp; Bros. Inc., Chicopee, Mass., a corporation of Delaware

Application November 22, 1940, Serial No. 366,539

Claims. (Cl. 154—18)

This invention relates to improvements in play balls, and particularly to noninflated or solid balls, such as are used for the games of golf and baseball. It also relates to improved methods of making such balls. To facilitate a description and understanding of the present invention embodiments thereof are hereinafter specifically described as embodied in a golf ball.

The almost universal use of “liquid cores” in golf balls testifies to the need of a yielding quality in the cores of golf balls to achieve maximum distance. It has been found experimentally, on the other hand, that a hard unyielding core has a detrimental effect on distance.

The usual liquid core consists of a liquid surrounded by a sac or shell of rubber. The liquid may be a true solution or it may have solid particles in suspension in it for the purpose of getting the proper weight.

The fact that the desired mobility is got by a liquid brings in its train certain disadvantages, some of which are obvious and some will only be apparent to those familiar with the difficulties of golf ball manufacture.

One obvious danger is that of leakage. The rubber windings constrict the core and, in highgrade balls, build up an internal pressure of 1500 pounds per square inch and higher. In spite of. great care during manufacture there are cores which under this tremendous pressure have leakage and consequently ruin the ball for use. With extreme vigilance good manufacturers can keep “leakers” to a minimum but the situation offers a constant manufacturing hazard and the necessary safeguards are expensive.

A liquid is difficult to handle, as shown by patents which attempt to make the core filling solid at one state so that it may be handled with ease and precision and then permanently liquify the core material before manufacture is finished. Possibly the oldest and commonest core is a thin sac with liquid filling; the thin wall distorts unevenly and neither the core nor the. winding on it are uniform. Many of the devices which attempt to surmount this inherent disadvantage are expensive. In the case of solids which are later liquified it is not easy to get reproducible degrees of fluidity.

It is an object of the present invention to provide high-grade golf balls with cores overcoming the above-mentioned disadvantages of liquid filled (and solid) cores, and yet having good or better flight and other characteristics.

Features of the present invention, resulting from the attainment of the objects, Include the provision of balls having cores loaded with a mobile pulverant material such particularly, as: dry sand, zinc stearate, dust, blanc fixe, powdered mica, graphite, carbonyl iron powder, etc., alone or certain of such pulverant material together. Mobile pulverant materials may be readily weighted out with precision, are easily and economically handled, are much less liable to leak out than fluids, will not evaporate, do not become unbalanced (like liquid centers with floating weight particles therein which may settle at one side of a core), facilitate adjusting or changing weight of balls because pulverant materials are obtainable in widely different specific gravity whereas different fluids are in general not of very different specific gravity, and offer many other advantages.

Another feature includes improved methods of making play balls wherein very uniform final results are assured, both in the manufacture and in the performance of the balls.

A further feature includes a ball having a sphere of pulverant material with an integral resilient shell therearound to hold or maintain the larger percentage of the pulverant particles therein in shiftable condition.

Other objects, features and advantages will be apparent or appear hereinafter.

In the drawing, which illustrates the present preferred embodiments of the invention:

Figure 1 is a cross-sectional view of a golf ball. Fig. 2 is a cross-sectional, and partially exploded, view of a core embodying a form of the invention.

Fig. 3 is a cross-sectional view including apparatus for magnetically holding the‘material in the core.

Fig. 4 is a cross-sectional view of another form of the present invention.

Fig. 5 is a cross-sectional view of the simplest form of the present invention.

Before describing the present improvements and mode of operation thereof in detail it should be understood that the invention is not limited to the details of construction and arrangement of parts shown in the accompanying drawing, which are merely illustrative of the present preferred embodiments, since the invention is capable of other embodiments, and the phraseology employed is for the purpose of description and not of limitation.

Before referring in detail to the drawing, and to the present preferred forms of the invention, brief explanation is made of some of the terms used. Thus, the term “pulverant” or “pulverant

3,376,084 material” as used herein relates to natural or comminuted materials in fine particles, or in a finely divided state, whether they be in the shape of grains, powder, dust, irregular, flaky, round or other substantially similar normally dry mobile 5 and free-flowing form. Some of the pulverant materials successfully tried include sand, blanc fixe and iron dust. In the present preferred forms of the invention these pulverant materials are preferably dry.

Tbe term “mobile” herein refers generally to the nonsolid, movable and free-flowing characteristic of the aforementioned pulverant material.

“Sintering” as used herein refers generally to the act of cohesively uniting pulverant material, or even slightly fusing or melting the outer surface of a pellet of pulverant material, enough to temporarily (or, permanently, when preferred) hold a mass of such material together long enough to assemble (or maintain) the same, for example, in a spherical or other shell-like member. Also, with some pulverant materials it is merely necessary to compact or compress the mass in order to cause the mass to hold together temporarily as a pellet.

“Filling or “completely filling” herein refers to loading a cavity with the pulverant material so that no section of the main cavity is without the mass of pulverant material (viz., no partial filling), although there may be some slight air spaces in the mass between the particles. In some instances jarring or vibration is utilized to insure a good compactness of the mass of pulverant material. .

Divers forms of pulverant materials, particularly powdered metals, and various methods of sintering, applicable with the present invention, are set forth in considerable detail in the book “Principles of Powder Metallurgy” by W. D. Jones, London, Edward Arnold &amp; Co., 1937.

Referring now in detail to the drawing, which discloses the present preferred embodiments of the invention, and first to Figs. 1 through 3, there is shown a golf ball 10 having a cover 11 of any suitable and well-known cover stock upon an intermediate member 12 of preferably resilient material such as a tautly wound rubber strand or strands upon a core 14 with a cavity 15.

The complete core 14 of the present invention is not like any of the many solid cores or liquid cores heretofore proposed.

It should be particularly noted that the core 14 is provided with a cavity 15 filled with pulverant material 16, such as described hereinbefore. It is desirable that this pulverant material completely fill the cavity, and preferably that it even be under pressure therein.

This core 14, as shown in Fig. 2, is preferably made of rubber, or other resilient material into cupped or hemispherical halves 14a and 14b with cavities 15a and 15b respectively adapted to receive a pulverant pellet 16' of like general configuration. The pellet 16', of pulverant material 16, is maintained in the cavity 15 by adhesively securing faces Ha and 17b together.

The pellet 16' may be the same size as the cavity 15 formed by the cavities 15a and 15b but is preferably slightly larger (compare size of expanded half 14b with the pellet therein against half 14a in Fig. 2) so that the pulverant material 16 is under pressure or compression from the assembled core 14, and to insure complete filling.

The pellet may be formed in any suitable manner. For example, it may be formed in well10 known plunger molds or pellet presses. With soms pulverant materials the mere compacting thereof in such molds or presses is sufficient to temporarily form the same into a pellet. Other materials may be provided with a thin glue, castor oil or other binder sufficient to temporarily hold the material together as a pellet. Other materials are preferably sintered, especially the outer surface or section thereof to form the temporary pellet. In some forms the pellets are formed by merely coating faces of the molds with a glue, castor oil or other suitable binder to be absorbed by the outer face of the pellet as it Ijs compacted in the press to temporarily act as an integral thin spherical shell. With any of these procedures the pellet of pulverant material is preferably only temporarily held together, as by a temporary cohesively or adhesively bonded surface and assumes a completely pulverant condition again, as during the final pressing together of the halves 14a and 14b which concurrently crushes the pellet back into a pulverant state. The loaded shell may be rolled or struck to change the temporary pellet back into a fully pulverant condition. However, in some instances the outer surface of the pellet may be sufficiently bonded or sintered to form a permanent resilient shell with the bulk of the mass therein still pul verant; e. g., use of a strong and resilient binder when coating the dies and when forming a shell at the outer surface of the pulverant material, lacquer being satisfactory for this purpose.

The pulverant material 16 in the core 14 may be placed under pressure, too, by compressing the core 14 by tautly winding the rubber strands forming the intermediate member 12.

Thus, the present invention provides a play ball, such as a golf ball, which has a mobile pulverant center; viz., one in which a mass of particles may be relatively moved.

Golf balls with liquid-filled cores are in general better for distance, life and other characteristics than balls with solid rubber cores or other nonliquid centers. Sample golf balls with the mobile pulverant centers or cores, made according to the present invention, have equaled flight of high-quality liquid-center golf balls. Also, they overcome many disadvantages prevalent with liquid-center balls (viz., (1) they are much less liable to leak; (2) can be enclosed within two like hemispherical halves without loss; (3) can be made according to (2) without piercing or plugging the spherical shell; (4) can be used to bulge hemispherical core shells; (5) will not evaporate; (6) provide easier and more accurate weight control; (7) facilitate weight changes or adjustment in balls; (8) expedite manufacture; (9) facilitate ball internal design or structural changes; etc.).

Fig. 4 is a slightly modified form of the invention hereinbefore described. The core 14 and pulverant material 16 may be any of the forms hereinbefore described in detail. This form of the invention differs from the previously described forms (Figs. 1-3, inclusive) primarily in the provision of one member 23 (instead of several) formed upon the core 14. This member 23 is preferably of resilient material. It may be a long strand or strands of rubber wound in great circles upon the core 14 and with the outer end adhesively or otherwise secured in place. Preferably, it is a soft rubber sphere suitably formed over the core as by molding or as by ad75 hesively securing two hemispherical shells over

2,37( the core 14, similarly to uniting shells 14a and 14b over the pellet 16'.

Fig. 5 shows the simplest form of the present invention and includes merely a spherical shell or core 14 with a cavity 15 for receiving pulverant material 16 either as a pellet, as described in connection with Fig. 2, or injected therein, as described in connection with Fig. 3. This shell or core 14 has a single wall of sufficient thickness to make a ball of the desired outside diameter. Any 1 desired or preferred surface configuration 24 may be formed on the shell or core 14.

The cores may be made with an opening for a plug, the iron dust or other pulverant material automatically and precisely weighed and forced ] into the cavity, and the opening closed with a rubber plug cemented into place.

The pulverant material if of magnetizable material such as iron dust may also be weighed separately into the two half shells 14a, 14b disposed in magnets and the iron dust compacted and held therein magnetically while one half is inverted over the other and the two halves united by cement.

It is also possible to make the dust into a stifi paste with a volatile solvent, weigh the paste into the two halves, invert, and then cement the two halves of the shell together; for example, pasting zinc-stearate With alcohol. In general, this is not preferred since time is required for the volatile solvent to diffuse out through the rubber wall and evaporate.

Briefly, the above-described methods may be outlined as follows:

(I) .Forming a pellet of pulverant material; and forming a resilient shell therearound.

(II) Forming a core or shell with a cavity therein; and completely filling said cavity with a pulverant material.

(HI) Either I or Π plus adding another resilient member therearound.

(IV) Either I, Π or m above plus adding a cover thereover.

(V) Either ΙΓ, HI or IV above, including the use of magnetizable pulverant and holding such pulverant in core shells magnetically; and (VI) Any of the foregoing I through V, including the step of first reducing the loose pulverant to a paste.

It is highly desirable that the pulverant completely fill the core cavities in order to transmit a blow on one side of a ball to the other sides thereof, and to bulge out the other sides, as well as to cause these other bulged-out sides to press on the pulverant material and thereby cause, help and insure a return of the struck side of the ball quickly to its normal condition.

Divers sizes of cores and core cavities may be used, dependent upon: the weight and bulk of the

1,084 pulverant materials used; the materials used in the cores; and, the final size of the ball. The pulverant material may be of divers “mesh,” kind and shape; for example, in addition to the 5 materials hereinbefore set forth, carbonyl iron may be used advantageously since it has the advantage of being magnetizable, and since it is of a generally small round shape so that the small particles thereof can roll upon each other. Com0 binations of pulverant material may be used.

Further, to insure a smooth flowing action between the pulverant particles and to prevent any frictional or abrasive action therebetween, the same may be given a light covering or film of 5 noncorrosive fluid; for example, glycerin may be used with iron and other pulverant materials. Carbon tetrachloride is also satisfactory as a lubricant for most of the pulverant materials. When such lubricant is used, or when certain θ pulverant materials are used which set up a corrosive action when associated with rubber, it is proposed to use neoprene or other of the now well-known noncorrosive or less corrosive rubber substitutes for the cores or as a lining for ₅ the cores. Glue and other antioxidant linings may also be used in any of the now well-known ways of lining or coating the inner surface of play balls.

Other variations and, modifications may be _B made within the scope of this invention, and portions of the improvements may be used without others.