Says Jim Graham, the gentleman that put the original together, "I built this ball-filler some years ago, and ever since, neighbourhood kids (my son included) have been using it to keep their footballs, their soccer balls and beach balls fully inflated."
Combining a portable "air pig" or "air hog" (a small air tank that you fill from a home or gas station compressor to take compressed air with you), and some simple compressed air plumbing, Jim has created a ball filler to take with you to the ball game, beach or what have you, and it's ready to bring any inflatable ball up to pressure fast!
Insert the fill-probe (item 4) through the rubber gasket into the ball. It is attached to a very flexible and soft polyurethane tube, making it convenient to reach the rubber fill-gasket on the ball.
As soon as the fill-probe is inserted through the rubber fill-gasket into the ball (and, as you may recall, the time honored way to seal the probe into the ball is with some saliva) the existing air pressure that is in the ball can be read on the large gauge (item 3).
Toggle the lever on the air valve (item 1) to start compressed air flow through the needle valve (item 2), along the polyurethane tube and into the ball through the rubber fill-gasket.
As the air pressure inside the ball increases, the air pressure can be monitored on the gauge.
When the ball is filled to a satisfactory pressure level, use the valve leaver to turn off the valve, remove the fill-probe from the balls rubber fill-gasket.
Any air pressure left in the fill line will now bleed to atmosphere through the tip of the fill-probe, so it might hiss a bit. That is normal.
If you are building this ball-filler you could consider using a spring-return valve which would shut off the air flow simply by letting go of the lever. That might even be a safer way to go, as letting go of the valve would immediately shut off flow to the ball.
Since compressed air flows very quickly, item (2) is an in-line needle valve which is used to control the air flow and reduce it to the minimum needed. This will help ensure that the ball isn't accidentally over inflated (and blown to bits by too much air). Use the needle valve to reduce the flow to a trickle, and you can have complete control over the speed with which any ball is filled.
Once you have set the needle valve to the flow you want, consider removing the adjusting knob from the needle valve to help ensure that "little fingers" don't dial the flow higher when you aren't around, in case the kids use the appliance in your absence.
Item (3) is a large-dial air gauge showing 0-10 PSI pressure range. This gage shows the pressure in the ball before the air valve is opened, and shows the increasing pressure as the ball is filled. Therefore, you want to get yourself a large, low range pressure gauge like this for the system you build. Of course, any compressed air gauge could be used. A small range, larger dial gauge makes reading the ball pressure easier.
Item (4) is the fill-probe, and in this photo it is sitting on top of the fitting. The fill probe is a standard one available from any sports store.
The fill-probe is attached to the air supply in the tank via a polyurethane tube. Polyurethane is very flexible, even in cooler temperatures. You can use polyethylene tube too, though it tends to kink if bent sharply and gets quite hard to bend when it's cold. Tube is available from any big-box hardware store, along with most of the fittings you will need for your ball filler.
Item (5) in the photo is a mini-filter regulator which filters the air supply before it gets to the ball-filler apparatus. It includes a regulator, and this regulator setting should be "dialed down" far enough to help eliminate ball over-pressurization. If you wish, please see the page the regulators page on this site for more info about compressed air regulators.
Once the correct pressure level is set, see if you can remove the regulator adjusting knob, to prevent further adjustment.
When built and set up properly, Jim Graham's ball-filler apparatus can easily and safely inflate sports balls to keep them in the optimum inflated condition, making the kid's games more fun to play.
In order to ensure safe operation I recommend that the use of the ball filler be overseen by an adult comfortable with compressed air and compressed air equipment.
Thanks to friend and mentor Mr. Jim Graham for this home-use application for compressed air.