Peristaltic pump with accommodating rollers

• US 4,095,923 A
• Filed: 08/16/1976
• Issued: 06/20/1978
• Est. Priority Date: 09/25/1975
• Status: Expired due to Term

• Current Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Original Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Inventors: Cullis, Herbert M.
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Ross, Thomas I.
• Application Number:
  US05/714,459
• Time in Patent Office: 673 Days
• Field of Search: 417/477, 417/476, 417/475, 417/474, 92/13.2, 308/184 R
• US Class Current: 417/475
• CPC Class Codes: F04B 43/1253 by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing

Abstract

The rollers of a peristaltic pump are provided with an unyielding surface, so as to insure uniform compression of the pumped tube. The rollers are mounted on their driving axles by means including yielding rubber bushings, whereby the rollers accommodate to varying diameters of pump tubing and do so without generating objectionable noise. Because the rollers yieldingly ride over the irregularities, two adjacent tubes of slightly differing diameters can simultaneously be contacted and stripped by one set of rollers.

Claims

1. A peristaltic pump which is capable of pumping two tubings of different diameter and which has an arcuate race;

one or more peristaltic pumping tubings disposed along the length of the race and having inlet and discharge portions;

a rotary shaft mounted to rotate about an axis coincident with the axis of said race;

a sweep arm;

means to adjustably mount said sweep arm on said rotary shaft;

a spindle fixedly mounted on said sweep arm in spaced relationship with said race, the constant distance between said spindle and said race being determined by the adjustment of the mounting of said sweep arm;

bearing means rotatable on said spindle;

a sleeve rotating about said spindle and supported by said bearing means;

annular elastomeric means supported by said sleeve; and

a rigid surface roller supported by said elastomeric means concentrically about said spindle;

said elastomeric means permitting skewing of the roller axis;

said rigid roller being of such size as to squeeze and substantially occlude said peristaltic tubing between the surface of said roller and the race at a given adjustment of said mounting of said sweep arm;

whereby, when said rotary shaft is rotated, the said rigid surface roller sweeps along the length of the one or more peristaltic pumping tubings in said race, thereby stripping said peristaltic pumping tubings and pumping fluid contained therein and forcing said fluid from said inlet portion to said discharge portion, and

whereby, when two peristaltic pumping tubings of different diameters are utilized, the rigid surface roller can be variably deflected as a result of deflection of the elastomeric support therefor by variable force applied to its rigid surface by two peristaltic pumping tubings, despite the said constant distance between said spindle and said race, determined by said adjustment of the mounting of said sweep arm.

2. The peristaltic pump of claim 1 in which the outer face of said roller is coated with a smooth coating of polytetrafluoroethylene.

3. The peristaltic pump of claim 1 in which the said arcuate race is a cylinder of revolution.

4. The peristaltic pump of claim 1 in combination with

guiding means, mounted on said rotary shaft and rotating therewith for guiding and confining the said one or more peristaltic pumping tubings to the portion of said race whereat it will be in operative relationship with said rigid surface roller.

5. The peristaltic pump of claim 4 in which said guiding means comprises guard arms which sweep along the race at the outer bounds of said portion of said race.

6. The peristaltic pump of claim 4 in which the said guiding means includes guiding rollers mounted on said guiding means for contacting said one or more peristaltic pumping tubings in its extreme position, at the edge of said portion of said race.

7. The peristaltic pump of claim 4 in which the said guiding means is located immediately ahead of said rigid surface roller, in the direction of its sweep, so as to contact said one or more peristaltic pumping tubings, when said tubing is in extreme position at the edge of said portion of said race;

whereby said guide means guides and confines said peristaltic pumping tubing immediately before it is squeezed and stripped by the said rigid surface roller.

15. The peristaltic pump of claim 1, wherein said annular elastomeric means comprise two spaced-apart annular rings of elastomeric material.

16. The peristaltic pump of claim 15, wherein each of said rings is spaced inwardly of one axial end of said roller.

17. The peristaltic pump of claim 15, wherein each of said rings has a radial thickness greater than its axial thickness.

8. For use in a peristaltic pump which is capable of pumping two tubings of different diameter and which has a race and has a spindle mounted on means to sweep along said race at a fixed distance therefrom;

a roller having rotational symmetry mounted concentrically on said spindle;

one or more peristaltic pumping tubings disposed along the length of the race and having inlet and discharge portions;

said roller being of such size as to suitably occlude said one or more peristaltic pumping tubings between a surface of the roller and the race;

the said surface of the roller being rigid and substantially unyielding to applied force;

bearing means mounted for free rotation about said spindle;

said roller being mounted on said bearing means for free rotation about the axis of said spindle;

a sleeve rotatable about said spindle and supported by said bearing means; and

annular elastomeric means between said sleeve and said roller for spacing the said surface of said roller from and for supporting said surface on said sleeve said elastomeric means permitting skewing of the roller axis;

whereby said rigid surface, as a whole, when two peristaltic pumping tubings of different diameters are utilized, can be deflected by pressure applied to any locale of said rigid surface by two peristaltic pumping tubings through deflection of said elastomeric means without appreciable local distortion of said rigid surface of said roller.

9. The roller of claim 8 having a layer of slick, low-friction material on said surface.

10. The roller of claim 9 in which the slick, low-friction material is polytetrafluoroethylene.

18. The peristaltic pump of claim 8, wherein said annular elastomeric bushing means comprise two spaced-apart annular rings of elastomeric material.

19. The peristaltic pump of claim 18, wherein each of said ring is spaced inwardly of one axial end of said sleeve.

20. The peristaltic pump of claim 18, wherein each of said rings has a radial thickness greater than its axial thickness.

11. A peristaltic pump which is capable of pumping two tubings of different diameter and which has a cylindrical race, a pump roller, and one or more peristaltic pump tubings having inlet and discharge portions occluded between said cylindrical race and said pump roller, forcing fluid from said inlet portion to said discharge portion;

a drive shaft rotating on the axis of said cylindrical race;

a sweep arm rotating synchronously about said axis and driven by said shaft;

bearings mounted on said sweep arm;

rotatable sleeve means mounted on said bearings;

annular elastomeric bushing means mounted on said sleeve means to spin freely in said sweep arm, and thereby defining a spin axis;

said spin axis being parallel to said axis of said cylindrical race; and

a hard-surface, rigid shell mounted on and supported by said bushing means and having an outer face which is concentric with the said spin axis;

said elastomeric bushing means permitting skewing of said shell axis;

whereby pressure applied to any locale of the said shell by said one or more peristaltic pump tubings does not locally distort said shell, but does distort the said elastomeric bushing and deflects the said shell as a whole without deflection of said synchronously rotating sweep arm, and whereby, when two peristaltic pumping tubings of different diameters are utilized, the rigid shell can be variably deflected as a result of the deflection of the elastomeric bushing means by variable force applied to the rigid shell by two peristaltic pumping tubings.

12. The peristaltic pump of claim 11 having a layer of polytetrafluoroethylene on the surface of said hard surface rigid shell.

21. The peristaltic pump of claim 11, wherein said annular elastomeric means comprise two spaced-apart annular rings of elastomeric material.

22. The peristaltic pump of claim 21, wherein each of said rings is spaced inwardly of one axial end of said shell.

23. The peristaltic pump of claim 21, wherein each of said rings has a radial thickness greater than its axial thickness.

13. A peristaltic pump which is capable of pumping two tubings of different diameter and which comprises:

a race having a central axis and an arcuate pumping face which is a figure of revolution about said central axis;

one or more peristaltic pumping tubings disposed along the length of the arcuate pumping face of the race;

a rotary shaft mounted to rotate about an axis coincident with the central axis of said race;

a sweep arm mounted on said rotary shaft;

bearing means mounted on said sweep arm in spaced relationship with the pumping face of said race;

said bearing means defining a planetary axis of rotation;

means to adjust the position of said bearing means with respect to said rotary shaft and thereby vary the spacing between said bearing means and the arcuate pumping face of said race;

an annular elastomeric roller support means, supported by said bearing means for rotation about said planetary axis; and

a rigid shell mounted on said elastomeric roller support means for rotation therewith about said planetary axis and having an exterior surface which is rotationally symmetric about said planetary axis;

said elastomeric roller support means permitting skewing of the shell axis;

said rigid shell being of such size as to squeeze and substantially occlude said one or more peristaltic tubings between the exterior surface of said rigid shell and the race at a given adjustment of said position of said bearing means;

whereby, when said rotary shaft is rotated, the said rigid shell sweeps along the length of the one or more peristaltic pumping tubings in said race, thereby stripping said one or more peristaltic pumping tubings and pumping fluid contained therein, and

whereby the rigid shell can be variably deflected by variable force applied to its rigid surface by two peristaltic pumping tubings of different diameter, despite fixed spatial relationship between said bearing means and said rotary shaft.

24. The peristaltic pump of claim 13, wherein said annular elastomeric means comprise two spaced-apart annular rings of elastomeric material.

25. The peristaltic pump of claim 24, wherein each of said rings is spaced inwardly of one axial end of said shell.

26. The peristaltic pump of claim 24, wherein each of said rings has a radial thickness greater than its axial thickness.

14. For use in a peristaltic pump which is capable of pumping two tubings of different diameter and which has an arcuate race symmetric about a central axis, one or more peristaltic pumping tubings disposed along the length of said arcuate race, and a rotary sweep arm rotating about said central axis and having bearing means for defining a planetary axis for mounting a peristaltic pumping roller of such size as to suitably occlude said one or more peristaltic pumping tubings between the surface of the said roller and the said arcuate race as said arm rotates about said central axis, to thereby pump fluid in said one or more peristaltic tubings;

the said roller having a surface which is rigid and substantially unyielding to locally applied force;

said roller being mounted on concentric bearing means for free rotation about said planetary axis; and

annular elastomeric means between said roller and said bearing means for spacing the rigid surface of said roller from and for supporting said rigid surface on said bearing means said elastomeric means permitting skewing of the roller axis;

whereby said rigid surface, as a whole, can be variably deflected by pressure applied to any locale of said rigid surface by two peristaltic pumping tubings of different diameters through deflection of said elastomeric means, without appreciable local distortion of said rigid surface of said roller.

27. The peristaltic pump of claim 14, wherein said annular elastomeric support means comprise two spaced-apart annular rings of elastomeric material.

28. The peristaltic pump of claim 27, wherein each of said rings is spaced inwardly of one axial end of said roller.

29. The peristaltic pump of claim 27, whrein each of said rings has a radial thickness greater than its axial thickness.