US736229A - Method of making hollow balls. - Google Patents

Description

No. 736,229. PATENTED AUG. 11, 17903.

' 0. DAVIS.

METHOD OF MAKING HOLLOW BALLS. 7 APPLICATION FILED APR. 11. 1902. 80 MODEL.

3mm addild 1762 4115,

:%W;'E T v I NITED STATES Patented August 11, 1903 ATENT FFICE.

CLELAND DAVIS, OF THE UNITED STATES NAVY, ASSIGNOR TO CAMBRIDGE MANUFACTURING, COMPANY, OF WILMINGTON, DELAWARE, A CORPO- RATION OF DELAWARE.

METHOD OF MAKING HOLLOW BALLS.

SPECIFICATION-forming part of Letters Patent No. 736,229, dated August 11, 1903.

Application filed April 11, 1902.

T0 aZZ whom it may concern.-

Be it known that I, OLELAND DAVIS, lieu tenant United States Navy, acitizen of the United States,stationed atWashingtomin the District of: Columbia, have invented certain new and useful Improvements in Methods of Making Hollow Balls, (Case E and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in the method of making elastic balls.

The object of my invention is to provide a method for easily and quickly making hollow elastic balls, commonly intended to be used as golf-balls, although, of.course, said balls may be used for other purposes.

In the accompanying drawings,which ill ustrate the way in which the invention is performed, Figure 1 representsa section through amold containing the ball. Fig 2 is a section through a modified form of ball as made byI my method and illustrates the ball before the plug is inserted; and Figs. 3 and -l are ,isections of other forms of finished ball, the

/ ball shown in Fig. 3 being of the same construction as that shown in Fig. 1.

The mold A is made of two separable members in the ordinary way.- The material to be molded into the form of a hollow ball is placed in the spherical cavity A in the mold,

and inclosed in the center of the mass is an inflatable bagB, of rubber, gold-beaters skin, or other suitable material, which bag is provided with a neck Z), through which water or other suitable fluid may be forced under pressure. Ordinarily I prefer to use an inelastic fluid, such as water, because a high pressure is more easily obtained. The inner walls of the mold A may be indented, if desired, to form projections 011 the ball such as are common in golf-balls. Various kinds of materials may be used in forming the shell of the ball. In Fig. 1 I have shown surrounding the inflatable bag B a hollow rubber core 0, which in turn is surrounded by a casing D, made of celluloid or some similar nitrocellulose compound. In the form shown in. Fig. 2

Serial No. 102,447. (No model.)

the ball consists of a single hollow shell of rubber, gutta-percha, or nitrocellulose com- 'passing outward through the tube 19. After the bag is filled with water and distended to the proper size it is placed within the mold A and the materialto be molded is placed around it. If desired,the mold may be slightly heated. ater under pressure is then forced into the bag 13 until the required pressure, which is something in the neighborhood of two thousand five hundred pounds, is produced, which pressure is sufficient to properly mold the ma terial, whether nitrocellulose, rubber, gutta percha, or other equivalent materials, into the desired shape and form. The ball is then removed from the mold and the water drained out. Air orother gas is then pumped in untila considerable pressure is obtained within the bag B. The cork E is then drawn up into the inner end of the tube 1), where it is firmly held by the air-pressure. The ball is then removed from the mold and the tube 1) is either cut off, if it is made of metal, or else folded back within the opening 0, as shown in Figs. 3 and 4, and the plug F, of suitable material, is inserted. Then the outer part or shell of the ball is made of a nitrocellulose compound,

this plug F may be made of the same compound and dipped in a suitable solvent, the result being that when the plug F is placed in position the parts will mold themselves together. The final result is a hollow elastic low hemispheres or other spherical segments and the contiguous edges may be welded together by heating, by the use of a suitable solvent, or in any other convenient way.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

i 1. The method of making hollow elastic balls, which consists in forcing an inelastic fluid into a hollow inflatable bag until said bag has assumed the proper size and shape, placing around said bag the material to be molded, inserting said bag and said covering material into a mold, forcing an inelastic fluid into said bag under pressure, thereby causing the outer material to assume the proper size and shape, removing the inelastic fluid from said bag, forcing an elastic fluid into said bag and finally sealing the orifice leading into said inflatable bag.

2. The method of making hollow elastic balls, which consists in forcing an inelastic fluid into a hollow inflatable bag until the latter has assumed the proper size and shape, placing around said bag the material to be molded, heating a mold, inserting the bag and covering material into said mold, forcing an inelastic fluid under pressure into said mold, thereby causing the covering material to be molded into the proper size andshape, removing said inelastic fluid from said bag, forcing an elastic fluid into said bag and finally elos ing the orifice through which said fluids were forced into said bag, in such a way as to make a homogeneous outside.

In testimony whereof I afflx my signature in presence of two witnesses.

CLELAND DAVIS.

W'itnesses: v

FRED W. ENGLERT, J. STEPHEN GIUsTA.

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