Patent ID: 7537575

Claim:
An apparatus for generating air pressure and air pressure pulses in an enclosure comprising: a casing having an air pulsing chamber and an opening, a diaphragm mounted on the casing closing the opening, means having a passage adapted to connect the casing to the enclosure for carrying air and air pressure pulses to the enclosure, a cover located over and spaced from the diaphragm having a pumping chamber, means securing the cover and diaphragm to the casing, said casing having an internal wall separating the pulsing chamber from a manifold chamber, said manifold chamber being in air communication with said pumping chamber, at least one valve mounted on the internal wall operable to allow air to flow from the manifold chamber into the pulsing chamber and prevent air to flow back from the pulsing chamber into the manifold chamber, an air flow regulator for restricting the flow of air into and out of the manifold chamber to control the pressure of the air in the manifold chamber, a drive mechanism connected to the diaphragm operable to reciprocate the diaphragm relative to the pumping chamber, said drive mechanism including a scotch yoke motion transmission including a yoke, a shuttle movably mounted on the yoke, an anti-lash assembly movably mounted on the yoke and engageable with the shuttle to retain the shuttle in continuous engagement with the yoke, and an eccentric rotatably mounted on the shuttle, a variable speed brushless dc motor connected to the eccentric whereby on operation of the motor the scotch yoke motion transmission reciprocates the diaphragm to pulse air in the pulsing chamber and cause air to flow from the manifold chamber into and out of the pumping chamber and increase the pressure of the air in the manifold chamber, said valve allowing air to flow from the manifold chamber into the pulsing chamber when the pressure of the air in the manifold chamber is greater than the pressure of the air in the pulsing chamber, and a programmable controller connected to the motor operable to vary the speed of the motor to regulate the reciprocating movement of the diaphragm thereby regulating the frequency of the air pulses in the pulsing chamber and enclosure.