US1551847A - Process and apparatus for making hollow elastic rubber balls - Google Patents

Description

' Sept. 1, 1925 R. E. RILEY PROCESS AND APPAIUXTUS FOR MAKING HOLLOW ELASTIC RUBBER BALLS Filed Oct. 31.

Patented Sept. 1, 1925.

UNITED STATES RALPH RILEY, OF

as, 01110, ASSIGNOR 'ro THE MILLER RUBBER COMPANY, or

AKRON, OHIO, A CORPORATION OF OHIO.

BRocnss AND APPARATUS FOR MAKING HoLLow'ELAsrIc RUBBER BALLS.

Application filed October 31, 1921. Serial- No. 511,720.

To all whom it may concern:

Be it known that I, RALPH E. RILnr, a citizen of the United States of America, residing at Akron, Ohio, have invented certain new and useful Improvements in Procasses and Apparatus for h-Ialnng Hollow Elastic Rubber Balls, of which the following is a specification.

'One object of the invent on 1s to provide a hollow playing ball having a decoration, design, picture or figure on its face which will be attractive and pleasing to the user, the ball being as elastic and as durable as an ordinary ball having no decoration thereon.

In carrying out the invention I a m to provide a construction which will avoid the use of objectionable paint or enamel, in providing the design or ornamentat on, and 1n which the elasticity of the ball Wlll be maintained indefinitely at approximately 1ts full degree throughout all its parts.

The invention concerns the process of producing the article, and means employed in its production.

In the accompanying drawmgs Figure 1 is an outside view of the ball.

Figure 2 is a sectional view.

Figure 3 is a view of an uncured ball and the inlay piece within an a plying devlce.

In these drawings 1 in icates the body material of the ball, and 2 the elastic sheet rubber piece providing the design. piece may assume various forms, and it may function in different ways, that is, it may be of the shape, in outline, of the figure, design, or picture, and being differently colored in respect to the balls body, it will of 1tse1f give an ornamental designer picture efiect, or, as shown, it is considered best to print on this piece the details of the picture or design.

This piece of rubber, for mstance,- may be white and the design may be prlnted thereon in red and black. The sheet rubber piece is trimmed to the outline of the design by means of cutting dies made to correspond to the outline of the printing form or plate.

In the production of the ball I take the two halves or blanks which make up the main body and cut them together with a blower and with entrapped air between, the resulting uncured article being of the shape indicated at 4 in'Figure 3. I then place the rubber piece or pieces 2 upon the uncured This ball body and because of the tacky condition the applying action, thereby dispensing with use of the pointed instrument. This consists preferably of a semi-spherical member of larger radius of curvature than the ball to be made. The sheet rubber design piece is placed 1n the applicator with its printed or design face against the inner side of the semi-spherical member, and then this applicator may be pressed by hand over the uncured ball body, or the application of the rubber piece to the uncured ball made in other ways, one of which will be referred to hereinafter. The sheet rubber piece is thus made to assume its proper shape to conform to thespherical shape of the ball and as above stated, owing to the tacky condition of arily attached thereto. 1

The applicator is now removed and the uncured ball with the thin sheet rubber'design piece attached thereto is now placed in a. mold and the heat of the mold generates gas from the blowerand softens thewubber so that the inlaying of the sheet rubber design member into the surface of the ball will be effected and the autogenous union between thls member and the body of the ball secured, while at the same time the ball is expanded to conform to the mold cavity.

I term this actiominlaying, as the sheet rubber piece is set into the surface of the ball flush therewith. This inlaying action takes place automatically when the heating in the mold and the generation of the gas from the blower takes place. The exterior of the completed ball is smooth and flush throughout, no joint being perceptible to the eye or touch where the edge of the design piece connects with the adjacent portion of the body of the the rubber the sheet rubber piece is temporor birds or human beings, all of which consist of a central body portion and limbs extending therefrom, are easy of application. Further, the material of the inlay piece being thin rubber, the tendency to buckle is slight. In the drawing it will be understood that the Mother Goose representation of a chicken in wearing apparel and carrying a basket consists of a rubber piece cut to the outline of chicken, basket, and wearing apparel and having its surface printed to complete the picture and this design presents the indented configuration well adapted for application to the ball without buckling.

Referring to Figure 3 the applicator may assume the form there shown at 3. This is approximately a semi-sphere of rigid-material slightly larger than the uncured ball which is indicated at 4. The rigid member 3 has sharp pins or bristles 5 set radially therein. The design or inlay piece is indicated at 2. This is laid on the pins by hand and the uncured ball is then placed in position and rocked in various directions and as the latter has a'tacky surface it will pick up the design piece, and the sharp points will cause the design to be tacked down at various points of its surface. Any tendency of the design to buckle is thereby obviated as the slack material will be divided up between the tacked points. The uncured ball. is then ready to be placed in the mold and when the ball expands the slack material between the tacked points will be stretched so as to conform to the ball. The portion of the surface of the uncured ball to which I apply the designs being that ortion which naturally would be slightly tiiinnedin stretching to conform to the mold, the designs applied to these points act to restore such portions to normal thickness so that the resulting article is uniform in thickness throughout. To make this clearer, reference is made to Fig. 3 where the shape of the uncured ball is substantially that of a prolate spheroid. The end portions will lie closer to the wall of the mold than the middle part of the wall of the uncured ball and therefore these latter portions will stretch to a greater degree when the gas from the blower expands the ball and this greater stretching of these wall portions will naturally thin them slightly 1n respect to the end wall portion. I therefore place the design pieces where they will add to the thinned portions and I preferably place a design member on each of the upper and lower wall portions of Fig. 3 so that the ball will be well balanced, and of equal resiliency at all points.

It will be understood that the design member is made of rub r considerably thinner than the wall of the ball, and it is found that the thickness of the composite wall portion of the ball where the inlay occurs is practically no thicker than the adjacent portions of the main wall of the ball. That is, the inlay adds no appreciable thickness at the point at which it is applied. A section of the ball out across the joint between the inlay and the main body wall reveals to the eye or touch no added thickness. There is no shoulder back of the joint but the interior appears as smooth and as free from any ribbed or shoulder eflect here as at the adjacent portions of the wall. This is doubtless due to the elasticity of the rubber and its capacity to stretch under the pressure of the gas.

The structure, therefore, is substantially of the same resilency at all parts.

The process described presents the advantages of quantity production at a cost that will enable marketing at a low price.

The sheet rubber piece is as elastic as the body of the ball, that is, all parts are elastic to about the same degree, and the ball will bounce approximately as high when the design portion hits the floor or other surface as when the main body of the ball hits.

It will be noticed that no cement is employed in uniting the sheet rubber piece to the ball, but the union is autogenous, and the ball, when fully cured, presents a perfect outer spherical surface, despite the fact that the design piece in the manufacture is laid onto the thickness of rubber constituting the body wall of the ball.

N o paint being used, the objection will be avoided of the design crazing, becoming chipped and dropping off. Where paint is used the rubber will deteriorate from the oil therein and its resiliency where the design is located will be lessened.

Figure 3 is of a-diagrammatic character, the uncured ball being represented in a conventional manner.

I claim:

1. The herein described method of making a decorated hollow elastic rubber ball which consists in printing an ornamental design upon a piece of thin uncured sheet rubber, attaching said thin uncured sheet to the tacky surface of an uncured hollow biscuit containing a gas forming medium, placing said biscuit with the attached decoration within a mold and subjecting the same to heat to cause the biscuit to be expanded and the decorated sheet to be inlaid in the surface of the biscuit and vulcanized thereto.

2. Means for applying a piece of sheet rubber to the tacky surface of an uncured rubber ballconsisting of a member of partly spherical shape of larger diameter than the uncured ball, and adapted to hold the sheet rubber, substantially as described.

3. Means for applying a piece of sheet rubber to the tacky surface of an uncured rubber ball consisting of a member of part- 1y spherical shape of larger diameter than projections upon which the sheet may be the uncured ball, said member having prolaid, and upon which the uncured ball may jections on its inner surface to receive the be rocked in various directions with the 10 rubber sheet, substantially as described; sheet rubber interposed.

6 4. Means. for applying a piece of sheet In testimony whereof, I afiix my signarubber to the tacky surface of an uncured ture. rubber ball consisting of a member having RALPH E. RILEY.

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