Patent ID: 8043077

Claim:
A micropump comprising: a tube frame including an elastic tube, and a tube guide groove for attachment of the tube in the form of an arc; a cam drive wheel whose rotation center is the same as an arc center of the tube guide groove, and moves in response to a motor that can be rotated in forward and reverse directions; a first cam that is axially fixed to a center axis of the cam drive wheel, and is provided with a finger depression section at a circumferential portion thereof; a second cam that is pivotally supported by the center axis of the cam drive wheel to be able to rotate, and is provided with a finger depression section at a circumferential portion thereof; and a plurality of fingers provided between the tube and the respective finger depression sections of the first and second cams radially from the rotation center, wherein the micropump can be in a first state of continuously feeding a fluid by, when the first cam is rotated in the forward direction, the first cam pushing and rotating the second cam in the same direction, by the finger depression sections of the first and second cams respectively depressing the fingers one by one, and by the fingers sequentially closing and opening the tube repeatedly from a fluid inflow side to a fluid outflow side, a second state of rotating only the first cam in the reverse direction at a time of, in the first state, a detection of a position where the finger depression section of the second cam releases the tube from depression by the fingers, and a third state of stopping the first cam from rotating at a time of, in the second state, a detection of a position where the first cam releases the tube from depression by the fingers, and the first state is retained by a drive command coming from the micropump being in the third state.