An inflatable sport ball, such as a basketball, a football, a soccer ball, a
volleyball
or a playground ball, is provided with a self-contained inflation mechanism, or
multiple self-contained inflation mechanisms, for inflating or more likely adding
pressure to the ball. The pump additionally contains an integral pressure relief
device to release air and relieve the pressure of the ball and/or a pressure-indicating
device to determine the relative pressure of the ball. The mechanism is a pump
which is inside of the ball and which is operable from outside of the ball to pump
ambient air into the ball.