US 2127487 A
Description (OCR text may contain errors)
Aug. 16, 1938. w. .1. von
I METHOD OF MAKING BALLS Original Filed Jan. 7, 1936 INVENTOR M/lLL/AM BY 7 dl/ T ATTORNEK ,Patented 'Aug. 16, 1938 UNITED STATES PATENT OFFlCE. I
2.127,? t METHOD OF MAKING BALLS William J. Volt, Los Angeles, Calif.
January 7, 1936, Divided M315 otgisis application August 8 Claims. (01. 154-13) Original application 57,907. 10, 1936, Serial No.
compacted fibrous material.
the cooperating leather pieces, such edges being generally secured together by the use of a characteristic back-and-forth stitch which has come to be known as the "baseball stitch. The technique of games played-with these balls has been in some measure developed around the characterlsticsof the balls. For example, a leather covered ball having a filled center has certain characteristics of rebound, flight, and handling. When struckwith a bat with a given force, the standard leather covered baseball will be impelled at a speed determined by or corresponding to its characteristics of weight, resilience, and external formation. In view of the known characteristics of commonly used baseballs, the playing field, or
diamond, and the rules of play have been given a desired relationship to the characteristics of the ball with which the game is played. The presence of the seam, and its stitches, has a definite influence on the action of the ball during flight and on the ability of the player or thrower to control the same, and accordingly it may be said that the manner of preparing the external surface of the ball has become a part of the game.
It is an object of'my present invention to provide 'a method for making a ball of the general character set forth .hereinabove, which ball may be used in the place of a standard leather covered ball in the playing of a game of ball without changing the manner of playing or technique of the game. My new ball is characterized by being more durable and by the ability to keep its spherical shape longer than the standard leather covered ball, but has the same characteristics of flight and handling as a leather covered ball which it replaces, these characteristics being accomplished by giving the surface of the ball the same gen'eral form as found on the surface of a leather covered ball, namely, the same seams and stitching, and the same character of surface finish between the seams.
It is a further object of the invention to prov acter and being missus) Serial No.
vide a method of making a game ball having a center of suitable composition of fibrous charequipped with a rubber cover, molded in place and having thesurface form set forth in the preceding paragraph, which game ball'will outlast or outwear leather covered balls in the place of which its use is intended.
This application is a division of my pending appication Serial No. 57,907, filed January 7, 1936, for Ball and method of making the same.
Further objects and advantages of the invention will be made evident throughout the following part of the specification.
Referring to the drawing, which is for illustrativepurposes only,
Fig. 1 is a partly sectioned view showing the manner in which a mold for making my new ball may be produced. Fig. 2 is a view showing the mold divided. Fig. '3 is a view showing the mold reinforced and provided with aligning means."
Fig. 4 is a view in cross section showing a center which may be used in the making of the new ball.
Fig. 5 is a view showing the rubber pieces which are to be applied to the surface of the center.
Fig. 6 is a sectional view showing a manner in which the rubber pieces may be applied to the center.
Fig. 7 is a sectional view showing the ball in the mold.
Fig. 8 is a partly sectioned view of a preferred embodiment of my new game ball.
The first step in the practice of my invention is to form a ball Ill having a leather cover of conventional stitches l 4 are formed passes intermittently under the edges of the pieces H and I2, the seams l3 are given a raised effect on the surface of the ball iii.
The leather with metal so as to produce a metal shell i6 covering the entire ball ill to a desired thickness. The shell l6, as shown in Fig. 2, is then divided on a medial plane, and the ball II] is removed cooperating mold parts I! covered ball in is then sprayed thereto by the ball II a the result of coating the produced by which has been placed on the surface of the cen- -metal fills all of the spaces or ball III with metal in sucha manner that the depressions in the surface of the ball. Accordingly, the surfaces I! of themold parts i1 and I. are pebbled, as indicated at 2|, in accordance with the grain surface. of the leather pieces II and I2 of the ball II, and the seams and stitches l2 and II of the original ball I! are represented by matrices 22 formed in the surfaces ll of the parts "and I6.
The surfaces I! are in fact negative representa tions of the cooperating halves of the ball "I.
As shown in Fig. 3, the mold parts l1 and i6 dividing the shell l6 are mounted in metal bodies 23 and '24 so as to form a mold of separable character, and dowels 25 may be provided for the purpose of aligning the halves of the mold indicated in toto by the numeral 26.
A ball core or center is then formed. One form of such center, as shown in Fig. 4, consists of a body 26 of fibrous material, such as kapok, wool, cotton waste, etc., with a surface layer of yarn 29 wound thereon, thereby producing a ball core or center 60 nearly as large as the original ball l0. To insure the adherence of the surface portion of the center '36 to the rubber cover to be subsequently applied, a coating 21 of rubber cement is applied to the winding of yarn 29, a portion of this cement penetrating into the'yarn so that it will act to bind the separate turns of yarn together as well as to cement the surface turns of the yarn to the rubber cover.
As shown in Figs. and 6, rubber pieces ii and 22 are placed upon the center Iii so as to cornpletely cover the same. With relation to the volume of the center 36, the. volume of the rubber constituting the rubber pieces 3i and 22 is such that the uncured ball shown in Fig. 6 will have a volume at least as great as, but preferably slightly greater than, the volume of the space within the mold so that when the mold is closed around the uncured ball, both the center 3|! and the rubber constituting the pieces 3| and 32 will be placed under compression, thereby assuring that the rubber cover of the ball will be tight upon the filler or center an. To make it possible to place the uncured ball shown in Fig. 6 in .the mold 26 without shearing or injuring the rubber ter 26, the center 36 is deformed to elliptical or egg-shaped form, so that the smallest diameter of the uncured ball will be, as indicated by D in Fig. 6, slightly less than the diameter of the spherical cavity of the mold. The rubber pieces 6i and 22 are made compound, and the piece 3! is preferably in the form of a strip which may be wound centrally around the center 26, as shown in Fig. 6, the pieces 22 being preferably in the form of discs adapted to be cupped over the exposed portions of the center, as shown at 22a in Fig. 6, the pieces ii and 22 being of such size that the edges thereof will overlap as indicated at 33.
' of the two The ball in its partly finished condition, as shown in Fig. 6, is then placed within the mold 26 with its equatorial plane of least diameter D coinciding with the plane of the abutting faces halves 22 and 26 of the mold 26, as shown inFig. '1. As the two halves 23 and 24 of the mold 26 are brought together, the center thereof, which was previously deformed to elongated or egg-shaped form, is pressed by the mold to spherical form, and in the preferred practice of the invention the closing of the mold 26 places the uncured ball under compression. To gain leased therefrom from a vulcanizable rubber best results, the volume of the unfinished bail shown in Fig. 6, that is, the volume of the center 30 with the rubber pieces 3i and 32 thereon, should be at least as great as the volume .of the interior space of the mold 26, or preferably slightly greater than the volume of the interior space of the mold, the result being that the center 20 will an outward force tending to hold the uncured rubber tightly against the inner faces I! of the be compressed and will exert mold during the curing process. I also contem- I plate in the practice of my invention the use of a gas pressure within the ball to assure that the rubber cover will be properly extended against the mold surfaces. To compensate for any slight defects in the shape of the center 30, internal gas pressure may be produced in any of the known manners now employed in the manufacture of hollow rubber goods. Before removal of the ball from the mold, the gas pressure is renormal temperature or by puncturing it with a bleeder needle. Illustrative of the step of bleeding gas pressure from the interior of the ball prior to its removal from the mold 26, I have in Fig. '7 shown a needle 40, of the character of a hypodermic needle, projecting through an opening ll in the wall of the mold part 24 and also through the rubber cover of the ball. die 40 is shown with a valve 42 associated therewith. Not only may the needle Mi be em'ployed for relieving gas pressure within the ball before removing it. from the I old, but it may be also employed as a means for initially creating a gas pressure within the ball. For example, after the uncured ball is placed in the mold 26, air under pressure may be delivered into the interior of the uncured ball through the needle 40 so as to provide the auxiliary gas pressure within the ball which the rubber which have not already been forced outwardly by the center into positive engagement withthe interior walls of the mold 26.
In Fig. 8, I show the finished ball 34 which now. has a continuous spherical rubber cover molded in place on the center 30 andcemento the center til. Under the heat of curing to which it is subjected within the mold 26, the vulcanizable rubber of the pieces 3! and 52 is formed into a continuous homogeneous layer. The rubber cover 35 has no actual seams, but due to the curing of the same in the mold previously described herein,
, is a replica of the surface of the original ball ii; that is, it has replicas i311 of the seams l3, has replicas Ha of the stitches H or the threads which formed the original stitches ll, and in addition thereto has a surface 2la exposed between the replicas Ila of the seams pebbled or grained in exact duplicate of the surfaces of the leather pieces ii and I2 of the originalball ll. ception that it has a one-piece molded rubber cover and is in this respect superior to a leather covered ball, has all of the characteristics of the standard or conventional approved leather covered ball, and may be used in games requiring the use of an approved leather covered ball. It will in no manner change the playing of the game, but will have the added advantage of retaining its shape for a maximum period of time and resisting skinning or scuffing of its surface. Having no sewed seams'to be broken by severe usage or to become opened by the wearing of the either by cooling the ball to,
a surface is This ball a, with the exthreads, the ball willlast for a much longer pletely surrounds said core, injecting air under a desired pressure through said rubber into said air-pervious core to thereby force said rubber into intimate contact with said mold, applying heat to vulcanize said rubber while maintaining said presthe steps of: forming a ball-center comprising compressible air-pervious material, placing rubber cover material about said ball-center, inserting said ball-center and rubber in a mold so that rubber while maintaining said pressure; relieving said pressure after vulcanization:
and removing the finished ball from said mold.
3. A method of making a substantially solid ball including the steps of: forming a core from withdrawing said needle from said said mold and removing the said mold.
pressure after vulcanization,
5. A method of making a substantially solid athletic ball including the steps of: taking a completed ball-center comprising material permold, ing pressure in said ball-center to force said rubher into intimate contact with said mold, applysaid ball-center while said pressure is effective, relieving said pressure, and removing the finished ball from said mold.
6. A method of making a rubber covered substantially solid article, including the steps of: forming a core comprising air-pervious' mateished ball from said mold.
8. A method, of making a substantially solid athletic wmmAM J'. vorr.