The present invention relates to an ink supply of the type having a diaphragm pump that is actuated by an actuator for providing ink to a printhead. The diaphragm pump includes a diaphragm and a chassis. The diaphragm has an integral pressure plate portion formed therein. The chassis and the diaphragm define a variable volume chamber. The chassis has a bias portion disposed therein for engaging the integral pressure plate portion to urge the pressure plate in a direction away from the chassis. The pressure plate urges the diaphragm away from the chassis to expand the variable volume chamber.