The Football (Soccer Ball)
2. The football bladder
Charles Goodyear was granted US Patent 3633 in 1844 for a method for vulcanising rubber. The patented process consists in mixing natural rubber with sulphur, making the rubber waterproof and resistant to changes in temperature, and thus suitable for a large range of applications.
Figure 2: Football with rubber bladder and rubber case (GB 1886-4359 A).
Rubber is also largely airtight and can be used for football bladders instead of the earlier pig bladders. This offers the following advantages: rubber is elastic and can be produced in any shape, allowing to largely avoid irregularities in the casing; it will not become porous or prone to cracks at low temperatures and has significantly better air retention properties. We do not know the exact date when a football was first equipped with a vulcanised rubber bladder.
The invention of the rubber football in 1886 was also based on the described findings. This football consisted of a very thin inner rubber ball which served as bladder, and a stronger outer rubber case (GB 1866-4359 A). The figure shows how the bladder is inserted into the case. The case a, pressed flat, has two reinforced apertures c. Bladder d is pulled through the apertures by means of inflation tube e. When pressure on the cover is reduced the bladder slides into the expanding inner chamber of the case while the tube is being retained. The bladder can then be inflated.
The development of pure rubber footballs will not be further explained in the following chapters.
Patent GB 1886-15726 shows a rubber bladder with a suitable valve for inflating the bladder. The valve is directly glued into a small aperture of the bladder as a stopper. Another early "valve" is obtained by means of pockets inside the bladder whose openings are self-closing due to the inner pressure (DE-PS 48317, 1888).
Figure 3: Chambered football bladder from DE 39 18 038 A1.
Only very few innovative concepts for bladder designs were developed in the following decades. One innovation concerned the division of the bladder into several bladder chambers, separated by elastic partition walls for increased stability (DE 39 18 038 A1, Figure). Another proposal related to the balancing of the bladder by means of opposite valves (WO 01/10512 A1).
Figure 4: Classical air pump for inflating footballs (GB 1887-12290 A).
Incidentally, according to GB 2 318 739 A (1998), a rubber bladder might be replaced by a bladder made of thin sheet metal, manufactured utilising aluminium-can manufacturing technology.
Likewise, air pumps and other tools for inflating the bladder did not develop significantly over the last 120 years. Inflators and the design of inflation tubes have not changed much since 1887 (GB 1887-12290 A). This can be seen from the figure showing a cross-sectional and a top view of an air pump for inflating footballs.
The only notable innovation concerns a self-contained inflating mechanism for sport balls (US 2003/0 130 076 A1), where a pump is provided in the interior of the ball.
Another new idea is to provide a bladder with two valves that can also be used to attach elastic cords for an electronic component to measure the speed, location, acceleration and trajectory of the ball (EP 3 287 175 A1).
Much more efforts were devoted to the shape and the protection of the bladder against forces occurring in the game and the inflation process. The same is true for valve technology and the positioning of the valve on the ball.
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| US 2003/0 130 076 A1 | 2003 | Sport ball with energy absorbing foam at varying locations | Self-inflating mechanism for footballs |
| WO 01/10512 A1 | 2001 | Balanced bladder for inflatable balls | Balancing a football by mounting two opposite valves |
| GB 2 318 739 A | 1998 | Metal inflatable ball | Football with sheet metal bladder |
| DE 39 18 038 A1 | 1989 | Ball, insbesondere Fußball | Bladder divided into several bladder chambers by means of elastic partition walls |
| DE-PS 48317 | 1888 | Elastische Ventile zum beliebigen Aufblasen und Entleeren von Gummibällen | Valve-like self-closing pockets provided inside a football bladder |
| GB 1887-12290 A | 1887 | A football inflator | Classical air pump for inflating footballs |
| GB 1886-15726 A | 1886 | Improvements in football bladders | A "genuine" valve glued into a rubber football bladder |
| GB 1886-4359 A | 1886 | Improvements in the construction of footballs | Football with rubber bladder and rubber case |
| US 3633 A | 1844 | Improvement in India-rubber fabrics | Method for vulcanising india-rubber |
| EP 3 287 175 A1 | 2018 | An inflatable ball bladder with two dual function valves and a wired rechargeable electronic component | Aufblasbare Ballblase mit zwei Doppelfunktionsventilen und einer drahtgebundenen wiederaufladbaren elektronischen Komponente |