A pump comprises a flexible diaphragm, a rigid member, an air seal formed between said diaphragm and said rigid member, a puller member attached to said flexible diaphragm, a drive member connected to said puller member which drive member is adapted to draw said puller member along with said diaphragm away from said rigid member, thereby creating a space between said diaphragm and said rigid member and forming a pressure region within said space, a motor drive mechanism including said drive member to reciprocate said puller member to first draw said puller member away from said rigid member and then move said puller member back toward said rigid member, an outlet in communication with said space between said diaphragm and said rigid member, and a vacuum regulator device on said rigid member for adjusting the level of negative pressure within said pressure region when said diaphragm is moved away from said rigid member.
