Peristaltic pump with replaceable displacement element

Abstract

A peristaltic pump includes a casing having a bottom, cover and wall forming a pump chamber, a tube connecting a casing inlet to a casing outlet arranged within the pump chamber, and a displacement element having at least two displacement members. The tube is arranged between the casing wall and the displacement element in such a way that due to rotation of the rotor the displacement members roll on the tube so the tube is squashed together so that a medium to be conveyed which is in the tube is displaced in the direction of the casing outlet. The displacement element has a first part fixed to the rotor and a second part which can be reciprocated between an operative position and a change position.

Claims

1. A peristaltic pump comprising a casing which has a casing bottom, a casing cover and a casing wall extending from the casing bottom to the casing cover, which form a pump chamber, and a casing inlet and a casing outlet which respectively provide a communication with the pump chamber, a tube which connects the casing inlet to the casing outlet and is arranged within the pump chamber, and a displacement element which has at least two displacement members and is fixed to a rotor which is rotatable about a rotor axis so that in the rotary movement of the rotor each displacement member of the at least two displacement members performs a movement in an operative plane, wherein the tube is arranged between the casing wall and the displacement element in such a way that due to rotation of the rotor the displacement members slide or roll on the tube so that the tube is squashed together and a medium to be conveyed which is in the tube is displaced in the direction of the casing outlet, characterised in that the displacement element is of a two-part structure comprising a first part which is fixed to the rotor and a second part which has a displacement member of the at least two displacement members, wherein the second part of the displacement element in at least one position relative to the rotor and the first part of the displacement element can be reciprocated between an operative position in which the operative planes of the at least two displacement members are identical and a change position in which the operative planes of the two displacement members are arranged parallel to each other, and wherein the second part of the displacement element is fixed to the rotor in both the operative position and the change position.

2. The peristaltic pump according to claim 1 characterised in that at least one part of the casing cover is removable and the second part of the displacement element in at least one position of the rotor is releasable from the first part of the displacement element.

3. The peristaltic pump according to claim 2 characterised in that each part of the displacement element has at least a displacement member or the at least two displacement members, wherein there are provided at least two support members, wherein at least one support member of the at least two support members is provided at each part of the displacement element, wherein by virtue of rotation of the rotor the support members of the at least two support members slide or roll on the tube, wherein the support members of the at least two support members are so arranged that they do not displace any conveyed medium in the tube.

4. The peristaltic pump according to claim 2 characterised in that the rotor is of a non-circular cross-section, wherein the first part of the displacement element and the second part of the displacement element have a through opening, an internal contour of which is of a configuration corresponding to an external contour of the rotor, so that when the first and/or the second part of the displacement element is pushed with its through opening over the rotor a positively locking connection is produced between the rotor and the first or second part of the displacement element.

5. The peristaltic pump according to claim 2 characterised in that the first part and the second part of the displacement element are connected together by way of a groove-sliding block connection, wherein a groove of the groove-sliding block connection extends parallel to the rotor axis, wherein the groove of the groove-sliding block connection is of an undercut configuration and a sliding block of the groove-sliding block connection is of a configuration corresponding to the groove of the groove-sliding block connection.

6. The peristaltic pump according to claim 2 characterised in that the displacement element and the tube are so arranged in the casing that by rotation of the rotor each displacement member of the at least two displacement members can be moved into a position in which the displacement member is not in contact with the tube.

7. The peristaltic pump according to claim 1 characterised in that each part of the displacement element has at least a displacement member of the at least two displacement members, wherein there are provided at least two support members, wherein at least one support member of the at least two support members is provided at each part of the displacement element, wherein by virtue of rotation of the rotor the support members of the at least two support members slide or roll on the tube, wherein the support members of the at least two support members are so arranged that they do not displace any conveyed medium in the tube.

8. The peristaltic pump according to claim 7 characterised in that the rotor is of a non-circular cross-section, wherein the first part of the displacement element and the second part of the displacement element have a through opening, an internal contour of which is of a configuration corresponding to an external contour of the rotor, so that when the first and/or the second part of the displacement element is pushed with its through opening over the rotor a positively locking connection is produced between the rotor and the first or second part of the displacement element.

9. The peristaltic pump according to claim 7 characterised in that the first part and the second part of the displacement element are connected together by way of a groove-sliding block connection, wherein a groove of the groove-sliding block connection extends parallel to the rotor axis, wherein the groove of the groove-sliding block connection is of an undercut configuration and a sliding block of the groove-sliding block connection is of a configuration corresponding to the groove of the groove-sliding block connection.

10. The peristaltic pump according to claim 7 characterised in that the displacement element and the tube are so arranged in the casing that by rotation of the rotor each displacement member of the at least two displacement members can be moved into a position in which the displacement member is not in contact with the tube.

11. The peristaltic pump according to claim 1 characterised in that the rotor is of a non-circular cross-section, wherein the first part of the displacement element and the second part of the displacement element have a through opening, an internal contour of which is of a configuration corresponding to an external contour of the rotor, so that when the first and/or the second part of the displacement element is pushed with its through opening over the rotor a positively locking connection is produced between the rotor and the first or second part of the displacement element.

12. The peristaltic pump according to claim 11 characterised in that the first part and the second part of the displacement element are connected together by way of a groove-sliding block connection, wherein a groove of the groove-sliding block connection extends parallel to the rotor axis, wherein the groove of the groove-sliding block connection is of an undercut configuration and a sliding block of the groove-sliding block connection is of a configuration corresponding to the groove of the groove-sliding block connection.

13. The peristaltic pump according to claim 1 characterised in that the first part and the second part of the displacement element are connected together by way of a groove-sliding block connection, wherein a groove of the groove-sliding block connection extends parallel to the rotor axis, wherein the groove of the groove-sliding block connection is of an undercut configuration and a sliding block of the groove-sliding block connection is of a configuration corresponding to the groove.

14. The peristaltic pump according to claim 1 characterised in that the displacement element and the tube are so arranged in the casing that by rotation of the rotor each displacement member of the at least two displacement members can be moved into a position in which the displacement member of the at least two displacement members is not in contact with the tube.

Description

(1) Further advantages, features and possible applications of the present invention will be clearly apparent from the description hereinafter of a preferred embodiment and the accompanying Figures in which:

(2) FIG. 1a shows a plan view of an embodiment according to the invention of a peristaltic pump,

(3) FIG. 1b shows a plan view of the peristaltic pump of FIG. 1a with the housing cover opened,

(4) FIG. 2 shows a perspective view of the rotor with drive unit,

(5) FIG. 3 shows a perspective view of the displacement element,

(6) FIG. 4 shows a perspective view of the first part of the displacement element,

(7) FIG. 5 shows a perspective view of the second part of the displacement element, and

(8) FIG. 6 shows a perspective sectional view through the displacement element.

(9) FIG. 7a is a perspective view of the displacement element shown in a working position.

(10) FIG. 7b is a perspective view of the displacement element of FIG. 7a shown in a change position.

(11) FIG. 1a shows a plan view of an embodiment of the peristaltic pump 1 according to the invention. The peristaltic pump 1 has a casing 12 having a casing bottom (not shown) and a casing cover 13 as well as a casing wall 14 extending between the casing bottom and the casing cover 13. It is also possible to see a casing inlet 15 and a casing outlet 16.

(12) FIG. 1b shows a plan view of the peristaltic pump of FIG. 1a with the casing cover 13 opened. The casing inlet 15 and the casing outlet 16 are connected together by way of a tube 17. It is also possible to see a displacement element 4 fixed to a rotor 2. The displacement element 4 has two displacement members 8. When the displacement element 4 is rotated by means of the rotor 2 about the rotor axis the displacement members 8 roll against the tube 17 and mechanically deform it so that fluid to be conveyed which is disposed in the tube 17 is urged within the tube 17 from the casing inlet 15 to the casing outlet 16. The peristaltic pump 1 does not need any valve. It is also self-blocking as in any position of the rotor 2 a displacement member 8 is directly connected to the tube 17 in such a way that it is elastically deformed in such a fashion that no fluid to be conveyed can flow through the deformed portion.

(13) FIG. 2 shows a perspective view of the drive unit 3 with the rotor 2. The rotor 2 is of a non-circular cross-section and in the illustrated embodiment the cross-section is cross-shaped. A drive unit 3 is capable of rotating the rotor 2 about its longitudinal axis, the so-called rotor axis.

(14) FIG. 3 shows a perspective view of the displacement element 4. The displacement element 4 comprises two parts, namely the first part 6 and the second part 7. Two displacement members 8 in the form of rollers are arranged on the displacement element. In addition there are two guide members 9 which are also in the form of rollers. The displacement members 8 are provided to deform the tube portion with which they come into contact in such a way that the flow through that tube portion is prevented. The guide members 9 also roll against the tube without however deforming it in such a way that a flow therethrough is still possible. The guide members 9 therefore do not serve a pump function but only serve to guide the tube. The displacement element 4 has a through opening 5, the internal contour of which is adapted to the external contour of the rotor 2. When the displacement element 4 is fitted on to the rotor 2 the rotor 2 and the displacement element 4 are positively connected together in such a way that the displacement element 4 follows the rotary movement of the rotor 2.

(15) FIGS. 4 and 5 show a perspective view of the two parts 6 and 7 of the displacement element, wherein for illustration purposes the second part 7 shown in FIG. 5 has been rotated through 180°. The two parts 6 and 7 each have a respective displacement member 8 and a guide member 9. In addition both parts 6 and 7 have a through opening 5 adapted to the external contour of the rotor 2.

(16) FIG. 6 shows a perspective sectional view through the displacement element 4. The through openings 5 in the two parts 6 and 7 are aligned so that the rotor 2 can be fitted through both through openings 5. It will be seen that one of the parts 6, 7 has a groove 11 of an undercut configuration, into which engages a corresponding rib in the form of a sliding block 10. That provides a positively locking connection.

(17) FIG. 7a is a perspective view of the displacement element 4 shown in a closed or working position in which the operating planes of the first part 6 and the second part 7 are the same. FIG. 7b is a perspective view of the displacement dement 4 of FIG. 7a shown in an open or change position and in which the operating planes of the first part 6 and the second part 7 are spaced apart, but are parallel to each other.

(18) To change the tube it is only necessary for the second part 7 of the displacement element 4 to be moved in the direction of the rotor axis relative to the first part 6 of the displacement element so that the operative plane formed by the associated displacement element 8 is displaced with respect to the operative plane of the displacement element 8 of the first part 6.

(19) That is possible generally only when the associated displacement element 8 is not in engagement with the tube. Possibly therefore firstly the rotor 2 including the displacement element 4 has to be rotated until the displacement member 8 of the second part 7 of the displacement element 4 no longer comes into contact with the tube. Then the second part 7 of the displacement element 4 can be displaced parallel to the rotor axis relative to the first part 6.

(20) In the illustrated embodiment it is even possible for the second part to be removed from the first part. As soon as the second part has been displaced relative to the first part or has even been removed the displacement element 4 can be further rotated until the displacement member 8 of the remaining part comes out of engagement with the tube. In that position no displacement member 8 is in contact with the tube so that the peristaltic pump is no longer self-blocking for that moment.

(21) It will be noted however that it is now possible for the tube to be easily removed and replaced by a fresh tube. Assembly is then effected in the reverse sequence, that is to say after the tube has been fitted into the housing then firstly the displacement element 4 is again rotated through 180° so that the first part 6 or its displacement member 8 comes into engagement with the tube again. The second part 6 can then be pushed on to the rotor 2 again so that the sliding block 10 moves within the groove 11. As soon as the operative planes of the two displacement members 8 are again identical the peristaltic pump is again ready for operation. The housing cover is possibly to be closed.

LIST OF REFERENCES

(22) 1 peristaltic pump 2 rotor 3 drive unit 4 displacement element 5 through opening 6 first part of the displacement element 7 second part of the displacement element 8 displacement member 9 guide member 10 sliding block 11 undercut groove 12 casing 13 casing cover 14 casing wall 15 casing inlet 16 casing outlet 17 tube