Peristaltic pump assembly and regulator therefor

1. A peristaltic pump assembly, comprising:

a pump body;

a cassette removably attached to the pump body, wherein the cassette includes a race configured to provide a compression surface for a tube supported by the cassette;

a roller assembly operatively connected to the pump body to rotate about an axis of rotation, wherein the roller assembly includes a plurality of rollers configured to apply a force to the tube, thereby compressing the tube against the race; and

a regulator disposed in the pump body and operatively connected to the cassette, wherein the regulator is configured to regulate the force applied to the tube;

wherein the regulator includes:

an L-shaped slide member having a first leg and a second leg perpendicular to the first leg, wherein the first leg and the second leg are non-rotatable relative to each other;

a pre-loading member, wherein the second leg of the slide member is mounted on the pre-loading member to permit the slide member to move as a unit in a linear direction relative to the pre-loading member;

a mounting pin carried by the first leg for rotatably mounting the cassette to the slide member, the mounting pin defining an axis of rotation of the cassette, wherein the mounting pin moves with the slide member in the linear direction;

a spring operatively connected to the second leg to apply a force in a direction orthogonal to the axis of rotation defined by the mounting pin.

2. The peristaltic pump assembly as defined in claim 1 wherein the pre-loading member engages the spring and extends through an opening in the second leg, wherein the pre-loading member is configured to apply an adjustable preload to the spring.

3. The peristaltic pump assembly as defined in claim 2 wherein the adjustable preload ranges from about 1.5 lbf to about 3 lbf.

4. The peristaltic pump assembly as defined in claim 2 wherein the pre-loading member is selected from shoulder bolts, screws, pegs, pins, shafts, or combinations thereof.

5. The peristaltic pump assembly as defined in claim 1 wherein, when the mounting pin moves with the slide member, the regulator regulates the force applied to the tube.

6. The peristaltic pump assembly as defined in claim 2 wherein the force applied to the tube, the preload to the spring, or combinations thereof are constant.

7. The peristaltic pump assembly as defined in claim 1 wherein the spring is selected from helical springs, clock springs, torsion springs, compression springs, extension springs, leaf springs, elastomeric bodies, or combinations thereof.

8. The peristaltic pump assembly as defined in claim 1 wherein the spring has a spring constant ranging from about 3 lbf/in to about 5 lbf/in.

9. A regulator for a peristaltic pump, the regulator comprising:

an L-shaped slide member having a first leg and a second leg perpendicular to the first leg, wherein the first leg and the second leg are non-rotatable relative to each other;

a pre-loading member, wherein the second leg of the slide member is mounted on the pre-loading member to permit the slide member to move as a unit in a linear direction relative to the pre-loading member;

a mounting pin carried by the first leg defining an axis of rotation, wherein the mounting pin moves with the slide member in the linear direction;

a spring operatively connected to the second leg to apply a force in a direction orthogonal to the axis of rotation defined by the mounting pin;

wherein the regulator regulates a force applied to a tube by a plurality of rollers of a roller assembly of the peristaltic pump.

10. The regulator as defined in claim 9 wherein when the mounting pin moves, the regulator regulates the force applied to the plurality of rollers.

11. A method of regulating a force applied to a tube by a plurality of rollers of a roller assembly in a peristaltic pump, thereby compressing the tube, the method comprising:

regulating the force applied to the tube using a regulator disposed in a pump body of the peristaltic pump and operatively connected to a cassette, the cassette being removably attached to the pump body, the cassette including a race configured to provide a compression surface for the tube;

wherein the regulator includes:

an L-shaped slide member having a first leg and a second leg perpendicular to the first leg, wherein the first leg and the second leg are non-rotatable relative to each other;

a pre-loading member, wherein the second leg of the slide member is mounted on the pre-loading member to permit the slide member to move as a unit in a linear direction relative to the pre-loading member;

a mounting pin carried by the first leg defining an axis of rotation, wherein the mounting pin moves with the slide member in the linear direction;

a spring operatively connected to the second leg to apply a force in a direction orthogonal to the axis of rotation defined by the mounting pin.

12. The method as defined in claim 11 wherein regulating the force applied to the tube is accomplished by moving the mounting pin.

13. The method as defined in claim 12 wherein moving the mounting pin is accomplished by:

compressing the spring upon mounting the cassette to the pump body; and

allowing the slide member including the mounting pin to move along a linear path.