Peristaltic pump

A method of pumping comprising the steps of:

• orbiting a plurality of rollers about a drive shaft in a circular orbit;
• positioning each of a plurality of flexible tubes in a corresponding one of a plurality of tube supports against a corresponding cam surface wherein each of the tube supports has mounted to it a corresponding guide surface spaced a programmed distance from the cam surface;
• and
• resiliently mounting said guide surfaces against said rollers, wherein said tubes are compressed to a programmed degree along their lengths;
• the step of resiliently mounting including spring biasing two halves of the tube supports apart at pivotable hinge means.

A method of pumping comprising the steps of:

• orbiting a plurality of rollers about a drive shaft in a circular orbit;
• positioning each of a plurality of flexible tubes in a corresponding one of a plurality of tube supports against a corresponding cam surface wherein each of the tube supports has mounted to it a corresponding guide surface spaced a programmed distance from the cam surface;
• resiliently mounting said guide surfaces against said rollers, wherein said tubes are compressed to a programmed degree along their lengths;
• and
• positioning a guide surface with respect to said rollers so that the rollers are spaced apart at least one-quarter of the length of the shortest guide surface between an end and a hinged point and less than three-quarters of the total length whereby said tube is not compressed until just before it begins releasing the tube near said outlet end.

Apparatus comprising:

• a cassette for a peristaltic pump;
• said peristaltic pump having rollers;
• said cassette having means for receiving at least one peristaltic pump tube and being adapted to cooperate with other cassettes on the same peristaltic pump;
• said cassette including means for providing multiple degree of freedom of motion for the cassette with respect to the rollers and other cassettes on the pump while the peristaltic pump operates, whereby the cassette contacts multiple rollers regardless of small errors in the dimensions of the cassette and in the location of the rollers;
• and
• said means for providing multiple degrees of freedom of motion for the cassette including a hinge permitting flexing about a central location and spring means for resiliently mounting the ends of the cassette over the rollers.

A cassette for a peristaltic pump adapted to include at least one flexible tube through which fluid flows having rollers adapted to squeeze said at least one tube to cause pumping of a fluid therethrough, comprising:

• at least one tube-holding means for providing a controlled sequence of different degrees of squeezing of said at least one flexible tube by the rollers based on the position of the rollers with respect to the tube-holding means;
• said tube-holding means including spring means for biasing said cassette against said rollers;
• and at least first and second surfaces;
• one of said first and second surfaces spacing the other from said rollers;
• the other of said first and second surfaces being adapted to bear against a flexible tube;
• said spring means being releasable;
• said at least one tube-mounting means including first mounting and second mounting means;
• said first and second mounting means being pivoted at a central location;
• and
• said spring means including at least one biasing means for resiliently and releasably biasing said first and second mounting means against said rollers and at least a second biasing means for resiliently biasing said first and second mounting means apart.

A peristaltic pump comprising:

• a motor;
• a drive shaft for said motor having a drive shaft axis;
• first and second flanges mounted orthogonally to said drive shaft for rotataion therewith;
• a plurality of rollers rotatably mounted to said flanges for orbiting about the axis of said drive shaft while being free to rotate in said flanges about their axes;
• a tube holding means;
• said tube holding means having mounted to it a cam surface means having a cam surface adapted to receive a tube;
• spring means for mounting said tube holding means to said peristaltic pump;
• a guide surface means having a guide surface;
• said cam surface being spaced from said rollers by said guide surface;
• said guide surface means being connected to the cam surface means;
• a flexible tube having a length and a flexible wall;
• said tube corresponding in position along a portion of its length to the cam surface;
• said tube holding means including at least one inlet and outlet tube holding means and said spring means including at least one means for spring biasing said inlet and outlet tube holding means and at least one pivoted hinge means;
• said cam surface means including inlet cam means mounted to said inlet tube holding means and outlet cam means mounted to said outlet tube holding means;
• said guide surface and plurality of rollers having dimensions such that successive rollers contact at least one-quarter of the guide surface between one end of the guide surface and the pivoted hinged means and less than three-quarters of the total guide surface whereby said tube is not compressed by each of said successive rollers until just before said each of said successive rollers begins releasing the tube near said outlet end;
• and
• the distance between said cam surface and the corresponding location on said guide surface changing from a distance less than twice the thickness of said wall of said tube to the diameter of said tube.

A peristaltic pump for pumping fluids through a plurality of tubes comprising:

• a drive shaft;
• a plurality of rollers mounted to said drive shaft for orbiting thereabout;
• a plurality of tube holding means;
• a plurality of cam surface means each having a corresponding cam surface;
• each of such tube holding means having mounted to it a corresponding one of said cam surface means adapted to receive a corresponding tube of said plurality of tubes on a corresponding one of said cam surfaces;
• a plurality of spring means for mounting said tube holding means with at least some of said tube holding means being movable with respect to others of said tube holding means while said peristaltic pump is operating to pump fluids, whereby said cam surfaces are independently self-adjusting;
• a plurality of guide surface means each having a different one of a plurality of guide surfaces;
• each of said cam surfaces being spaced from said rollers by a corresponding one of said guide surfaces incorporated in the tube holding means, whereby the amount each of said tubes of said plurality of tubes is squeezed by said rollers depends upon the distance between its corresponding guide surface and cam surface;
• and
• said distance between corresponding guide surfaces and cam surfaces differing at different positions along the guide surfaces so as to provide a controlled sequence of degree of squeezing of the tubes by rollers based on the position of the rollers along corresponding guide surfaces.

A peristaltic pump for pumping fluids through a plurality of tubes comprising:

• a drive shaft;
• a plurality of rollers mounted to said drive shaft for orbiting thereabout;
• a plurality of tube holding means;
• a plurality of cam surface means each having a corresponding cam surface:
• each of said tube holding means having mounted to it a corresponding one of said cam surface means adapted to receive a corresponding tube of said plurality of tubes on a corresponding one of said cam surfaces;
• a plurality of spring means for mounting said tube holding means;
• a plurality of guide surface means each having a different one of a plurality of guide surfaces;
• and
• each of said cam surfaces being spaced from said rollers by a corresponding one of said guide surfaces incorporated in the tube holding means, whereby the amount each of said tubes of said plurality of tubes is squeezed by said rollers depends upon the distance between its corresponding guide surface and cam surfaces;
• said distance between corresponding guide surfaces and cam surfaces differing at different positions along the guides surface so as to provide a controlled sequence of degree of squeezing of the tubes by rollers based on the position of the rollers along corresponding guide surfaces;
• each of said spring means;
• including inlet and outlet spring biasing means for biasing said tube holding means toward said rollers;
• and spring-biased pivotable hinge means for biasing said tube holding means away from said rollers;
• said inlet and outlet spring biasing means including at least a first spring and said spring-biased pivotable hinge means including at least a second spring said first spring being stiffer than said second spring.