Patent ID: 6948918
Filing Date: 2005-09-27
Classification: A61M,F04B,F16K

Abstract:
1. A pump device comprising: a pump housing, a pump cavity formed within the housing, the pump cavity comprising a first wall portion and an opposed second wall portion, the first wall portion having a generally hollow configuration and the second wall portion having a generally raised configuration relative to the pump cavity, a pump membrane comprising a first membrane surface and a second membrane surface, the pump membrane being arranged within the pump cavity, a pump chamber defined between the first wall portion and the first membrane surface, an actuation chamber defined between the second wall portion and the second membrane surface, inlet means in fluid communication with the pump chamber, outlet means in fluid communication with the pump chamber, wherein the pump membrane has a maximum volume position in which the second membrane surface in a stretched state abuts and substantially conforms to the general configuration of the second wall portion, and a drained volume position in which the first membrane surface in a stretched state abuts and substantially conforms to the general configuration of the first wall portion, and actuating means for periodically shifting the pump membrane between the maximum volume position and the drained volume position, whereby metering accuracy of the pump device is determined by the first and second wall portions.