An information distribution system which, even when the number of participating terminal apparatuses increases, can easily manage an operating history of each terminal apparatus. The requester then sends a request to the grantor of the computer for an increase in the computer performance. A biasing unit biases the pressing unit to move relative to the mounting seat so as to press the follower unit of the pressing unit against the camming element of the wheel seat, thereby turning the camming element toward a central position. The gas duct plate has a multiplicity of through-holes, a gas duct and a multiplicity of gas duct holes extending from the gas duct to the functional plate and the functional plate has a multiplicity of through-holes and depressions open to the gas duct plate. The present invention ensures that an operator does not disable one of the two switches such as by taping it closed.