GB2102504A

GB2102504A - Peristaltic pump

Info

Publication number: GB2102504A
Application number: GB08135448A
Authority: GB
Inventors: Norman David Leaman; Thomas John Mcneel Robertson
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-06-18
Filing date: 1981-11-25
Publication date: 1983-02-02
Also published as: GB2102504B

Abstract

The pump comprises a pumping tube 1 wound helically on a drum 2, which may be hollow (as shown), the tube being compressed by a roller(s) 4 on a rotating arm(s) 5 driven by a spindle 7. The rollers may be connected to the spindle by toothed gears, Figure 2 (not shown), and may be resilient, Figure 3 (not shown). The tube may be flanged to facilitate fixing thereof to the drum, Figure 4 (not shown). <IMAGE>

Description

SPECIFICATION Peristaltic pump It is known that a peristaltic pump can comprise: resilient tubing as a duct; and at least one pressure surface for compressing successive localities on the exterior of that tubing so as to compress transversely the flow way in said tubing, any said compressed locality relaxing to recover at least part of its precompressed state, after said pressure surface is removed from that compressed locality. The succession of compressed localities and corresponding relaxations thereof cause fluid to be pumped along said flow way. The succession of compressed localities can be regarded as a transverse wave travelling in the required direction of flow of pumped fluid.

The present invention provides a peristaltic pump, comprising: at least one peristaltic duct comprising at least one compressible flow way; carrier means supporting said at least one duct, said duct being in a spiral path extending in at least one direction relative to the configuration of said carrier means; and pressure means comprising at least one pressure application surface for applying pressure to successive localities on the exterior of at least one said supported duct so as to compress transversely the flow way therein and thereby provide peristaltic pumping of fluid, e.g. gas, liquid, fluidised solid, or any mixture chosen from those examples of fluids.

When not compressed, the flow way in any duct can have any suitable cross-sectional configuration, preferably a curved configuration, e.g. at least partly circular. It will be appreciated that the words "duct" and "tubing" can be regarded as synonomous.

Preferably, the cross-sectional configuration of the uncompressed flow way is uniform along the uncompressed operative length of the duct. The flow way at the inlet or outlet of the duct need not necessarily have the same cross-sectional configuration as the flow way at any other portion of the duct.

Any said duct can be constituted by at least one material, e.g. by natural and/or synthetic material, for instance natural rubber, synthetic rubber, or a polyalkene (for instance polythene also known as polyethylene). Any wall of the duct can be heterogenous (e.g. a portion not the whole of the duct can be compressible) or homogenous (e.g. the whole of the duct be compressible).

The exterior of any duct can be adapted to facilitate cooperation between that duct and said carrier means, e.g. the duct can have at least one flat, and/or at least one flange, and/or key. Any said flange can comprise at least one aperture for receiving fastening means for fastening the duct to said carrier means, e.g. at least one fastener lace (for instance a wire) can be laced through a row of said apertures.

At least one limitation means can be provided to limit at least partly one dimension of any duct. At least one first limitation means can limit at least a portion of the longitudinal configuration of the duct.

At least one second said limitation means can limit at least a portion of the cross-sectional configuration of the duct. A single or different limitation means can constitute a said first and a said second limitation means. For example, at least one filament can constitute at least one said limitation means. Any said filament can comprise at least one material, e.g.

cotton, jute, linen, nylon, rayon, or metal. Preferably, any said filament is incorporated in the material of the duct at the time of manufacture of the duct. At least one said limitation means can stabilise at least one property of the duct, e.g. bursting pressure or resilience of the duct.

The carrier means can be constituted in any suitable way, e.g. comprise at least one periphery of revolution preferably of uniform radius (for instance, the periphery of a barrel, disc, drum, frame, or wheel). Preferably, said carrier means is adapted so that during successive contractions of any duct, the radial compressions undergone by the duct are substantially the same. For that purpose, the periphery of said carrier means is preferably of substantially uniform cross-sectional configuration along the path of the supported duct. However, that cross-sectional configuration could vary along said path so as to enable at least one differential in said radial compressions. Preferably, the carrier means enables said path to be a spiral configuration having a minimum of 1 turn and a fraction of 1 turn, and any suitable helix angle(s).

At least one fastener means can be provided to fasten any duct to said carrier means, e.g. a said fastener lace, adhesive, bolts, key means, rivets, screws, or any combination chosen therefrom.

At least a portion of any said pressure application surface can be position fixed or position adjustale in at least one dimension and/or direction. For example, position adjustability can be constituted by resiliency of material of any pressure application surface, and/or by any adjustment means, for instance an adjustable arm or other means to which a pressure application surface can be mounted. A pressure application surface could be mounted to a non-adjustable arm. Any adjustable or nonadjustable arm that can rotate is a generator of a notional periphery of revolution. Thus, any said arm can be replaced by a corresponding equivalent, e.g.

disc, frame, or the like. At least one said adjustment means can comprise at least one bias means (e.g.

spring means) to bias at least one said pressure application surface in at least one direction. When there is a plurality of said pressure application surfaces, a plurality of the same or different said adjustment means can be provided for compensating or reducing irregularity(s) of operation between at least two said pressure application surfaces, preferably so as to assist and/or enable those surfaces to provide substantially the same applied pressures on any duct. Any suitable resiliency of those surfaces can assist that purpose. The areas of contact of a plurality of pressure application surfaces with any duct can be of any size(s) and in any distribution or pattern with respect to each other.It will be appreciated that by apropriate locating, loading, and sizing of the pressure application surfaces, various components of motion can be applied to fluid within the duct, e.g. to provide continuous or pulsing flow, preferably non rotational, continuous flow.

The pump can comprise at least one drive means for giving at least one component of motion to at least one said pressure application surface. Motion of a said pressure application surface can be adapted to resist any tendency of the peristaltic duct to move longitudinally in the pumping direction of the fluid.

Preferably, at least one said pressure application surface will move in a path that preferably does not change in at least one plane. At least one said pressure application surface can be driven whether or not any further pressure application surface is not driven. At least one said drive means can be adapted to compensate or relieve any motional mismatch between at least two said pressure application surfaces. For example a said drive means can be adapted to be operative disengaged for that purpose, e.g periodically to enable a pressure application surface to be motionally free, e.g. freewheel. At least one said drive means can have at least one degree of freedom of motion (preferably with a centralising bias) so that when a said disengagable drive means is re-engaged, at least one drive means will reorientate itself sufficiently to relieve a said mismatch.Re-engagement can be at different times during said free motion, for instance a toothed gear can be re-engaged on different teeth at different times for at least a portion of a cycle of rotation.

Preferably, at least one said pressure application surface is the surface of a pressure application roller that can move in at least one path, e.g. orbit in a closed figure. Examples of said drive means are: electrical drives means (e.g. an electric roller mounted in orto a pressure application roller); hydraulic drive means; mechanical drive means; pneumatic drive means. Any said drive means can utilise any convenient mechanical devices, e.g. belts, chains, clutches, differential mechanisms, gears (e.g.

toothed or threaded gears, racks, sprockets, or worms), or rotating shafts; or any combinations chosen therefrom.

Said pressure means can be adapted so that, for at least one given time, at least one said pressure application surface will compress at least one portion of only one turn of said spiral configuration.

Said pressure means can be adapted so that, for at least one given time, at least one said pressure application surface will compress at least one portion of each turn of a plurality (e.g. 2 turns) of a plurality of said turns.

The peristaltic pump can comprise guide means for guiding the peristaltic duct in at least one path.

Preferably, said carrier means comprises at least one said guid means, e.g. as a relieved and/or projecting portion of said carrier means, against which said duct can abut or in which said duct can be seated.

The present invention will now be illustrated by way of example with reference to the accompanying drawings, in which: Figure 1 schematically shows one embodiment of a peristaltic pump.

Figure 2 schematically shows another embodiment of a perstaltic pump, which is a modification of the pump of Fig. 1.

Figure 3 schematically shows the construction of one pressure application roller.

Figure 4 schematically shows the construction of one peristaltic tube.

In Figure 1, polymeric peristaltictubing 1 is in a spiral configuration on a cylindrical drum 2 provided with guides in the form of half-sectional tubes 3 in which tubing 1 is seated. Opposite ends of tubing 1 project into the hollow interior of drum 2 so as to provide inlet and outlet ends for tubing 1. The exterior of a freely rotatable, pressure application roller 4 can orbit and act to compress successive localities on the exterior of tubing 1, so as to contract radially the flow way in that tubing and thereby provide peristaltic pumping of e.g. water. Roller 4 is rotatably mounted to a rotatable arm 5. Roller 4 is also rotatably mounted to a rotatable arm 6, the arms 5 and 6 being at opposite ends of the drum 2.

Only one of arms 5, 6 can be provided if desired. The arms 5, 6 are rotatably mounted to a spindle 7 concentric with the axis of the drum 2. The spindle 7 can be driven by any suitable means, e.g. an electric motor. If desired, roller 4 can be provided with a direct drive (e.g. an electric motor) or reduction gearing or other coupling. Drive can be via a shaft concentric with spindle 7, power take off from that shaft being provided by any suitable means.

In Figure 2, at opposite ends of drum 1 are respectively a first set of diametrically opposite arms, 25, 25' and a second set of corresponding arms 26,26'. Arms 25,26 support therebetween a pressure application roller 24. Arms 25' and 26' support therebetween a further pressure application roller 24'. A power driven spindle 27 is supported with a hollow shaft 28. At one end of spindle 27 is a worm 29 engaging pinions 30,31 which are respectively mounted to shafts 32 and 33 so as to transmit rotation to those shafts. At the other ends of shafts 32,33 are pinions 34 and 35 which respectively engage bevel gears 36 ad 37 mounted to respective ends of rollers 24, 24' so as to transmit rotation to those roller, and thereby enable those rollers to travel around and compress successive locations on the exterior of tubing 1.Rotation of driven shaft 27 can be by any suitable means, e.g. an electric motor.

It will be appreciated with reference to Figure 2 that undesirable strains might be produced after a period of operation if there is inequality in the diameters of rollers 24, 24'. This inequality can be relieved by incorporating differential gear mechanism that will continuously relieve any rotational mismatch between the rollers 24, 24'. This would be relatively easy for the two driven pressure applica- tion rollers but would lead to considerable complication if there were more than two said rollers. One preferred alternative which would be suitable for any plurality of rollers would be periodically to diengage the power drive to one roller at a time. During the disengagement, the relevant roller and its associated drive mechanism will freewheel while the remaing roilers(s) is being driven. If, in addition to disengagement of drive the roller drive mechanisms have some free movement (preferably with a centralising bias), those mechanisms will reorientate themselves slightly with respect to the power input spindle and relieve said mismatch by re-engaging on a different pinion tooth from time to time after a number of periods of freewheeling. In the case of Figure 2, worm 29 can have an interruption in the thread thereof so that for each revolution of the worm 29, the pinions 30,31 disengage for a shorttime.

Inaccuracy in manufacture of the drums 2 of Figs.

1 and 2 (e.g. lack of concentricity between drum 2 and the centre rotation of any said arm, or ovality of drum 2) might result in undesirable pressure on tubing 1. Thus, to alow for minor departures from theoretical geometry, it is preferable to incorporate some compensating mechanism to ensure that pressure application rollers maintain sunstantially the same pressures on tubing 1. This compensation can be provided by incorporating a telescopic section in any said arm. However, to maintain mechanical rigidity of an arm, it is preferred to constitute its pressure application roller with a pressure compensating device(s), e.g. by providing the roller with a resiiient surface and/or biased-loaded movement between the exterior of the roller and its axis of rotation.

In Figure 3, springy, curved plates 19 (e.g. of tempered steel or manganese bronze) are mounted to the hub 20 of a said roller. The exterior of the roller is a cylinder 21 positioned over plates 19, which then act as spokes to locate resiliently that cylinder.

In Figure 4, tubing 1 has a flat 42 from opposite edges of which extend flanges 43 and 44 each provided with a row of holes 45 for enabling at least one wire to lace the tubing 1 to drum 2. The longitudinal dimension of the tubing 1 is reinforced by means of filaments 46. Although not shown, further reinforcing filaments could be provided around the wall of the flow way in tubing 1.

Preferably the helix angle of the tubing 1 will be chosen (e.g. by utilising guide channels 3 of Figure 1) so that gradual change in configuration of tubing 1 will be imparted such that the pressure application rollers will during their motions progressively compress and release tubing 1 and thereby enable preferred impact loads of those rollers on tubing 1.

It will be apreciated that the embodiments shown in the accompanying drawings can be modified in accordance with the above description given before the description of those drawings. For example, the arms 26 and 26' are optional and need not have been provided in Figure 2's embodiment. In general, the present invention includes any equivalent or modification within the scope of the claims of the present application.

CLAIMS (Filed 16 June 1982) 1. A peristaltic pump, comprising: at least one peristaltic duct comprising at least one compressible flow way; carrier means supporting said at least one duct, said duct being in a spiral path extending in at least one direction relative to the configuration of said carrier means; and pressure application means comprising at least one pressure application surface for applying pressure to successive localities on the exterior of at least one said supported duct so as to compress transversely the flow way therein and thereby provide peristaltic pumping of fluid.

2. A pump as claimed in claim 1,wherein uncompressed flow way in at least one said duct has a curved cross-sectional configuration.

3. A pump as claimed in claim 2, wherein said cross-section configuration is at least partly circular.

4. A pump as claimed in any one of claims 1 to 3, wherein cross-sectional configuration of uncompressed flow way in at least one said duct is substantially uniform along uncompressed operative length of the duct.

5. A pump as claimed in any one of claims 1 to 4, wherein there is at least one tubular said duct.

6. A pump as claimed in any one of claims 1 to 5, wherein the exterior of at least one said duct is adapted to facilitate cooperation between that duct and said carrier means.

7. A pump as claimed in claim 6, wherein the exterior of at least one said duct has at least one flat, and/or at least one flange, and/or at least one key.

8. A pump as claimed in claim 7, wherein at least one said flange comprises at least one aperture for receiving fastener means for fastening the duct to said carrier means.

9. A pump as claimed in any one of claims 1 to 8, comprising at least one limitation means for limiting at least partly one dimension of at least one said duct.

10. A pump as claimed in claim 9, wherein at least one said limitation means limits at least a portion of longitudinal configuration of a said duct.

11. A pump as claimed in claim 9 or 10, wherein at least one said limitation means limits at least a portion of cross-sectional configuration of a said duct.

12. A pump as claimed in any one of claims 9 to 11, wherein at least one filament constitutes at least one said limitation means.

13. A pump as claimed in claim 12, wherein at least one said filament in incorporated in material of a said duct at the time of manufacture of that duct.

14. A pump as claimed in any one of claims 1 to 13, wherein said carrier means comprises at least one periphery of revolution.

15. A pump as claimed in claim 14, wherein said periphery of revolution is substantially of uniform radius.

16. A pump as claimed in claim 14 or 15, wherein said periphery of revolution is constituted by a barrel, disc, drum, frame or wheel.

17. A pump as claimed in ay one of clams 1 to 16, wherein said carrier means is adapted so that during successive contractions of at least one said duct, radial compressions undergone by the duct are substantially the same.

18. A pump as claimed in any one of claims 1 to 17, wherein said carrier means enables said spiral path to be a spiral configuration having a minimum of 1 turn and a fraction of 1 turn.

19. A pump as claimed in any one of claims 1 to 18, comprising at least one fastener means for fastening at least one said duct to said carrier means.

20. A pump as claimed in claim 19, wherein at least one said fastener means comprises: fastener

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. pinion tooth from time to time after a number of periods of freewheeling. In the case of Figure 2, worm 29 can have an interruption in the thread thereof so that for each revolution of the worm 29, the pinions 30,31 disengage for a shorttime. Inaccuracy in manufacture of the drums 2 of Figs.

lace(s); adhesive(s); bolts(s); key means; rivet(s); or screw(s); or any combination chosen therefrom.

21. A pump as claimed in ay one of claims 1 to 20, wherein at least one said pressure application surface is position fixed.

22. A pump as claimed in any one of claims 1 to 21, wherein at least one said pressure application surface is position adjustable in at least one dimension and /or at least one direction.

23. A pump as claimed in claim 22, wherein at least one said pressure application surface is movable in at least one path.

24. A pump as claimed in any one of claims 1 to 23, wherein at least one said pressure application surface is surface of a pressure application roller.

25. A pump as claimed in any one of claims 1 to 24, wherein said pump comprises at least one adjustment means for position adjustability in at least one said pressure application surface.

26. A pump as claimed in any one of claims 1 to 25, comprising means for assisting and/or enabling a plurality of said pressure application surfaces to provide substantially the same applied pressures on at least one said duct.

27. A pump as claimed in any one of claims 1 to 26, comprising means for compensating and/or relieving motional mismatch between at least two said pressure application surfaces.

28. A pump as claimed in any one of claims 1 to 27, comprising at least one drive means for giving at least one component of motion to at least one said pressure application means.

29. A pump as claimed in claim 28, wherein at least one said drive means is adapted to compensate or relieve motional mismatch between at least two said pressure application surfaces.

30. A pump as claimed in claim 29, wherein at least one said drive means is operatively disengagable for compensating and/or relieving motional mismatch between at least two said pressure application surfaces.

31. A pump as claimed in claim 30, wherein at least one said drive means has at least one degree of freedom of motion so that when a said disengagable drive means is re-engaged, at least one drive means will reorientate itself sufficiently to relieve motional mismatch between at least two said pressure application surfaces.

32. A pump as claimed in claim 30 or 31, wherein at least one said drive means comprises toothed gear re-engagable on different teeth at different times for at least a portion of a cycle of rotation thereof.

33. A pump as claimed in any one of claims 28 to 32, wherein at least one said drive means comprises: electrical drive means; hydraulic drive means; mechanical drive means; or pneumatic drive means.

34. A pump as claimed in any one of claims 1 to 33, comprising at least one guide means for guiding at least one said duct.

35. A pump as claimed in claim 34, wherein said carrier means comprises at least one said guide means.

36. A pump as claimed in claim 35, wherein said carrier means has a relieved and/or projecting portion thereof, against which at least one said duct abuts or in which at least one said duct is seated.

37. A pump as claimed in claim 1, substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.

38. A pump as claimed in claim 1, substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.

39. A pump as claimed in claim 1, substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.

40. A pump as claimed in claim 1, substantially as herein before described with reference to and as shown in Figure 4 of the accompanying drawings.

41. A method of pumping fluid, comprising effecting said pumping with at least one peristaltic pump as claimed in any one of claims 1 to 40.

42. A method as claimed in claim 41, wherein said fluid comprises gas.

43. A method as claimed in claim 41 or 42, wherein said fluid comprises liquid.