US2302985A - Method of making footballs - Google Patents

Description

Nov. 24,1942. w. J. von' Erm. ,3

amaon or IAKIHG roo'mms Filed Sept. 3. 1940 ii Patented Nov. 2 1942v UNITED STATE 5 PAT-EN T ome METHOD OF MAKING FOOTBALLS I William J. Volt, Los Angeles, and Leltli C. Welmer, Southgate, Calm; said Weimer assignor to said Volt Application September a, 1940, Serial No. 355,176 7 Claims. (CL 154-16) present undulations-interfering with the proper This invention relates to a method of making footballs and ,other hollow inflatable athletic play balls.

innermost layer isadapted to receive and retain the air of inflation. An outermost layer is The walls of athletic play balls of this type are. usually built up of a number of layers, each layer 7 being adapted to fulfill a distinctive purpose. An

adapted to resist wear and abrasion caused by contact of the ball with external objects, and an.

intermediate layer or layers are adapted to provide additional material to resist puncture and to strengthen the ball against enlargement in diameter under the pressure of inflation. All of the several layers by their composition and in their relationship toeach other are adapted to give the ball the requisite play qualities as to resiliency and inother respects.

A layer of wound stranded material, such as fibrous thread or cord, has been found to be effective 'to serve as an intermediate reinforcing .layer between the air retaining innermost layer and the outermost protective covering layer.

. Sometimes this stranded material is wound upon the ball in great circles, or near great circles, the crossing points of the circles being scattered and rather generally distributed over the surface of the balL, In other cases the stranded'material is spirally wound about an axis of the ball as a center, the winding beginning at or adjacent one pole of this axis and terminating at the other pole thereof. In the manufacture of footballs, a spiral winding of this character is about the long axis of the football, it being obviously impractical to wind stranded material in elliptisigned to feed the stranded material at a uniform tension to the ball. But unless the wall of the ball to which the stranded material is being fed is substantially rigid, it will be temporarily depressed and furrowed by the stranded material at the point of winding contact with the result performance of the ball when placed in use.

It has been the practice to attain the desired rigidity of the wall of the ball upon which the stranded material is wound, by building the ball upon a form of solid material; This form is later removed through an opening in the ball which must be left in the layer or envelope ofwvound,-

stranded material as well as in any layers of the ball beneath the-winding. Either provision is madefor lacing this opening, or the opening is permanently closed at later stages ofmanufacture of the ball. The method of employing a rigid form to ensure even winding of the stranded material upon the ball obviously presents several difilculties, and the resultant product has disadvantages no matter which methodof closing the opening for the form is used.

that the wound ball will be misshapen and will as It is one object of this invention'to provide rigidity in the foundation wall upon which stranded material isto be wound,.in summer which shall obviate the difilculties and disadvantages attendant upon the use of a solid re-' movable form.

It is another object to afford arapid inexpensive and simple method of winding at even 4 tension a stranded material upon a ball core or foundation.

It is another object to provide a method of manufacturinga ball which will produce a ball which will not lose its original shape or size, which will be durable, and which will have the requisite play characteristics.

The invention is herein described in connec- .tion with the manufacture of a football. In some respects the invention is, applicable to the manufacture of hollow, inflatable athletic footballs of other than the'ellipsoidal'shape of th' standard football. 1

In the drawingi Fig. l is a vertical, sectional view of a disposed within a curing mold.

Fig. 2 is an elevational view illustrating sthe manner in which a reinforcing wall is applied to the bladder.

l 'lg. 3 is a vertical section taken along the line I 3-3 of Fig. 2. v

Flg. 4 is an elevational view illustrating the manner in which stranded material is next wound upon the ball.

Fig. 5 shows the completed ball with resisting cover applied thereto. I The first step in the manufacture of the football is the making' of the air-retaining innermost a wearlayer of the ball, commonly called the bladder.

bladder.

bladder ll through the valve which may be rubberized, are then,

2 This may be made in any suitable manner, but preferably pieces of relatively thin sheeted rubber or otherrubber-like material are secured together along their marginal edges in the shape of a football to form an air-retaining bladder l I. An inflation valve 12 of a suitable character is securedin place in the bladder ll. preferably at a place midway of the ends it and ll of the bladder; The bladder is then placed in a mold l5 provided with air-conveying means l6, by which air may be forced into the interior of the [2. The bladder is then inflated and while under inflation is subjected to a heat cure, which hardens the rubber material ofthe bladder and gives it the deflnite form ofa standard football. I

, Air pressure in the bladder is removed; the bladder is taken from the mold and reinflated to a size somewhat less than that desired for the completed football. Pieces ll of woven fabric,

adhesively applied to the inflated bladder preferably with lapped marginal joints. These pieces may be of any number and configuration, but it has been found satisfactory to cover the entire surface of the bladder with at least four similarly shaped and equally dimensioned pieces ILeach extending from the end "to the end I of the football.

In applying the pieces II to the bladder, the

bladder may be. initially dipped in latex or similar material, or rubber cement may be applied to the under surface of the pieces "before application to the bladder.

The fabric covered bladder is next placed in a mold of slightly larger dimensions than the mold IE, but otherwise similar thereto. In this mold the ball is inflated by air at a relatively high pressure, for example 90 to 100 pounds, which forces the wall of the ball into intimate contact with the inner surface of the mold, stretching the fabric material of the pieces l'l. While thus inflated and while the pieces H are in stretched condition, the ball is given a heat-cure, which fixes it in shape and size.

The ball is now deflated sufliciently for removal from the mold and again inflated to a relatively high pressure. When thus inflated it presents at all points a hard unyielding surface, which can only be dented by the application of a very heavy inward thrusting stress. The ball is now placed in a winding machine and thread or cord, -or other stranded material I8 is spirally wound upon it, beginning at a point the ball and terminating at-a point near the other end or pole ll of the ball. This cord is preferably rubberized.

End caps 2i and- 22, consisting of small concave-convex pieces of rubber or rubberized fab- |9 near the pole IQ of .properly cured. It is to the cover flowed into the space between the ball and the mold, and vulcanizingly united to the ball in the usual manner.

The mold for this last vulcanization may be formed with impressions to cast in the surface of the rubbercover of the ball any desired markings such as simulations 24 of the lacing of a leather ball, these markings facilitating the handling of the ball by the players as well as improving the appearance of the ball.

Or, a leather cover may be given the ball by adhesively' applying to the cord-wound carcass a plurality of leather panels, and thereafter preferably giving the leather covered ball a pressure treatment in a mold preferably at a low temperature.

The process is subject to a number of variations without departing from the spirit of the invention. While, as described above, the ball is given a vulcanizing cure after each application of material thereto, one or more of these vulcanizing steps may be omitted from the process, provided that when the ball is completed the rubber material of all of its parts has been be preferred, however, that the bladder be at least partially cured before the application of the pieces of fabric, and it is also preferable that the fabric covered ball be enlarged somewhat by internal air pressure and that the rubber material of the fabric be cured while the fibers thereof are in their stretched condition. The word rubber as herein used is meant to include not only natural rubber but synthetic materials having the reprising: making a ric, are adhesively applied to the ball at its rell. These polar caps have thickness as the diameter of the stranded material I! if the latter is wound upon the ball in a single ply, or as the total thickness of the layer of cord windings, if there is more than one ply of windings.

The cord wound ball may now be given a heatcure in a mold and afterward provided with a wean-resisting cover, or it may be provided with the cover without an intermediate molding cure. The wear-resisting cover may be a one-piece rubber envelope 23 formed by vulcanizing in place upon the ball a plurality of pieces of rubberg or the ball may be mounted within a mold and in spaced relationship with the internal surface of the mold and a spective ends I! and substantially the same liquid rubber material for silient character of rubber such as materials classed as "synthetic rubber.

We claim as our invention:

l. A method of making an athletic ball, comvalved air-retaining bladder of rubber-like material; inflating said bladder to a relatively low pressure .and to a size slightly smaller than that of the completed ball; bondin to said inflatedbladder an envelope of fabric woven material highly resistant to tensile stresses; inflating said enveloped bladder without substantial enlargement to a substantially higher pressure sumcient to substantially resist the inwardly directed stresses applied thereto during the operation of winding at a substantial tension a reinforcing layer of stranded material thereon; winding stranded material at a substantial tension on and bonding it to said inflated bladder to form a reinforcing layer; and applying and bonding a wear-resisting cover to said ball.

2. A method of making an athletic ball, comprising: making a valved air-retaining bladder of rubber-like material; inflating said bladder to a relatively low pressure and to a size slightly smaller than that of the completed bail; bonding to said inflated bladder an envelope of fabric woven material highly resistant to tensile stresses; inflating said enveloped bladder without substantial enlargement to a substantially higher pressure suflicient'to substantially resist the inwardly directed stresses applied thereto during the operation of winding at a substantial tension a. reinforcing layer of stranded material thereon; spirally winding stranded material at a substantial tension on and bonding it to said inflated enveloped bladder between opposite poles to form 'a reinforcing layer; and applying and bonding a wear-resisting cover to said ball.

3. A method of making an ellipsoidal football, comprising: making a relatively thin walled incured pieces of fabric material highly resistant to tensile stresses; inflating said fabric covered bladder without substantial enlargement to a substantially higher pressure suflicient to render inwardly it locally substantially unyieldable when subjected to the stresses arising from winding thereon stranded material at a substantial feed tension adequate for properly forming a reinforcing envelope of stranded material;

subiected to the stresses arising from winding thereon stranded material at a substantial feed tension adequate for properly forming a reinforcing envelope of stranded-material; spirally winding on the inflated fabric covered ball rubberized stranded material at substantial tension and about the long axis of the ball; applying a wear-resisting, rubber cover to the ball; and giv ing the ball a vulcanizing cure in a mold.

6. A method of making an ellipsoidal football,

comprising: making a relatively thin walled mflatable bladder of rubber material having an inflation valve, and in the shape of the completed article; inflating said bladder to a relaspirally winding stranded material on the inflated fabric covered bladder at a substantial tension and about the long axis of-the bladder; applying a wear-resisting covering envelope to the ball; and giving the ball a vulcanizing cure in a mold.

4. A method of making an ellipsoidal football,

comprising: making a relatively thin walled inflatable bladder of cured rubber material having an inflation valve, and in the shape of the completed article; inflating said bladder to a relatively low pressure and to a size slightly smaller than that of the completed ball; applying there- 'to with a vulcanizable rubber adhesive an envelope of marginally secured, lune-shaped pieces of rubberized fabric material highly resistant to tensile stresses; inflating said fabric covered bladder without substantial enlargement to a substantially higher pressure sufficient to render it locally substantially unyieldable inwardly when subjected to the stresses arising from winding thereon stranded material at a. substantial feed tension adequate for properly forming a reinforcing envelope of stranded material; spirally winding on the inflated fabric covered bladder rubberized stranded material at a substantial tension and about the long axis of the bladder; curing the ball in a mold; and applying a wear-resisting cover to the ball.

5. A method of making an ellipsoidal football, comprising: making a relatively thin walled inflatable ball of cured rubber material having an inflation valve, and in the shape of the completed article; inflating said ball to a relatively low pressure and to a size slightly smaller than that of the completed ball; applying thereto' with a vulcanizable rubber adhesive an envelope of marginally secured, lune-shaped pieces of rubberized fabric material highly resistant to tensile stresses; inflating said fabriccovered ball without substantial enlargement to a substantially higher pressure sufllcient to render it 10- cally substantially unyieldable inwardly when tively low pressure and to a size slightly smaller than that of the completed ball; applying thereto, with a vulcanizable rubber adhesive, an envelope of marginally secured pieces of rubberized fabric material highly resistant to tensile stresses; vulcanizing said envelope and bladder; I

inflating said fabric covered. bladder without substantial enlargement to a substantially higher pressure suflicient to render it locally substantially, unyieldable inwardly when subjected to the stresses arising from winding thereon stranded material at a substantial feed tension adequate for properly forming a reinforcing envelope of stranded material; spirally winding on the inflated fabric covered bladder rubberized stranded material at a substantial tension and about the long axis of the bladder; curing the ball in a mold; and applying a wear-resisting cover to the ball.

7. A method of making an ellipsoidal football, comprising: making a relatively thin walled inflatable bladder of rubber material having an inflation valve, and in the shape of the com-- pleted article; inflating said bladder to a relatively low pressure and to a size slightly smaller than that of the completed ball; applying thereto by means ofvulcanizable rubber adhesive and withmarginally lapped joints, pieces of fabric material highly resistant to tensile stresses to form an envelope; inflating said fabric covered bladder without substantial enlargement to a substantially higher pressuressuflicient to render it locally substantially unyieldable inwardly when subjected to the stresses arising from winding thereon stranded material at a substantial feed tension adequate for properly forming a reinforcing envelope of stranded material; spirally'windlng stranded material on the inflated fabric covered bladder at a substantial tension and-about the long axis of the bladder;

applying a wear-resisting covering envelope tothe ball; and giving the ball a vulcanizing cure in a mold.

WILLIAM J. VOIT. LEI'II-I C. WEHMER.

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