Improved peristaltic pump and method for managing such a pump

Abstract

The invention relates to a peristaltic pump comprising a housing (11), a bearing surface (12) comprising an outer face, said bearing surface (12) having a deformable intermediate bearing surface from which rigid bearing arms (14, 15) extend on either side thereof, the free end of each of these lateral arms having at least one guide element (16), said housing having tracks (17) on which these guide elements are capable of sliding to constrain the displacement of the free ends of the rigid lateral arms so as to deform the intermediate bearing surface. According to the invention, said bearing surface (12) being made of plastic, said outer face having one or more recesses (18) extending in the pumping direction, at least one of these recesses having an anti-creep device to prevent deformation of said intermediate bearing surface. [Fig. 1]

Description

Title of the invention: Improved peristaltic pump and method for managing such a pump. Technical field

[0001] The technical field of the present invention is that of volumetric pumps, and more specifically of peristaltic pumps with deformable tube.

[0002] The present invention also relates to a method for managing such a peristaltic pump. Previous technique

[0003] Peristaltic pumps are well known and used in many technical fields, for example the chemical industry, the cosmetics industry, the petroleum industry, the food industry, and in medicine, particularly for transporting blood or other liquids administered by infusion, ...

[0004] A peristaltic pump consists of a frame on which is fixed a motor whose axis drives in rotation a cage comprising a plurality of rollers.

[0005] These rollers, free on their axis, successively crush a deformable tube until it is sealed.

[0006] The alternating pressure and release on the walls of the deformable tube creates a vacuum and a suction so that a fluid trapped between the rollers in the deformable tube is thus pushed along the length of the tube.

[0007] A fluid pumped at an open end of the deformable tube, called the inlet or upstream end, is thus discharged at the other end of the deformable tube, called the discharge or downstream end.

[0008] A main advantage of this peristaltic pump is that the fluid thus displaced remains intact during its transfer since it is never in contact with the rollers but only with the internal wall of the deformable tube.

[0009] The peristaltic pump therefore constitutes a particularly healthy pumping solution.

[0010] A large majority of peristaltic pumps include a casing having an internal cylindrical face, called the bearing surface, against which the deformable tube is crushed by the rollers to ensure the sealing of the tube.

[0011] This span can take the form of a metallic blade exhibiting a certain elasticity, this span having a unique predetermined shape.

[0012] Alternatively, this bearing surface can be made of a plastic material, for example by molding. An obvious advantage of this type of bearing surface is that it It is possible to give any desired shape to the inner face of this bearing surface, the face against which the deformable tube comes to rest when crushed by the rollers.

[0013] However, in peristaltic pumps equipped with such a plastic bearing, a progressive deformation of the latter is observed over time, this is the phenomenon known as "creep".

[0014] This creep can have several causes and result in particular from repeated mechanical actions exerted on the bearing surface, during the crushing of the deformable tube, but also from the thermal environment in which the peristaltic pump is immersed during its implementation.

[0015] The inner face of the bearing can then exhibit surface variations over time, which are likely to lead to a loss of sealing of the peristaltic pump.

[0016] There is therefore an urgent need for a peristaltic pump with a reach made of plastic, the original design of which makes it possible to overcome the disadvantages of the prior art described above. Object of the invention

[0017] The present invention aims to overcome the disadvantages of the prior art by proposing a peristaltic pump, simple in its design and in its operating method, whose internal bearing surface is not affected by creep-related deformations.

[0018] Another object of the present invention is such a peristaltic pump allowing an adjustment of the deformation of the intermediate bearing part obtained by displacement of the lateral bearing arms relative to the main axis of this peristaltic pump.

[0019] Another object of the present invention is such a peristaltic pump exhibiting a greater diversity of operation.

[0020] Another object of the present invention is a method for managing such a peristaltic pump, allowing the deformation of its span to be managed for specific needs. Description of the invention

[0021] To this end, the invention relates to a peristaltic pump comprising a housing, a bearing surface comprising an inner face and an outer face, said bearing surface having an intermediate bearing portion from which bearing arms extend on either side thereof, this intermediate bearing portion being deformable, the inner face of this intermediate bearing portion having semi-cylindrical symmetry about an axis coinciding with a principal axis of said pump, said bearing arms being rigid, the free end of each of these lateral arms comprising at least one guiding element, said housing comprising tracks on which these guide elements are capable of sliding to constrain the movement of the free ends of the rigid lateral arms so as to deform the intermediate bearing part, the radius of its inner face being modified while leaving the axis of the intermediate inner face in coincidence with the main axis of said pump. According to the invention, this bearing being made of a plastic material, the outer face of said bearing has one or more housings extending in the direction of pumping, at least one of these housings receiving an anti-creep device to prevent deformation of said intermediate part of bearing and / or said housing comprising two parts of housing body between which said bearing is placed, said pump includes at least one anti-creep device connecting said two parts of housing body bearing on the outer face of the bearing to prevent deformation of said intermediate part of bearing.

[0022] Advantageously, the original design of this peristaltic pump makes it possible to guarantee its optimal operation by maintaining the original shape of the inner face of the bearing over time.

[0023] When the outer face of the span includes one or more housings to receive one or more anti-creep devices, these housings are preferably formed by molding the span in plastic material. As an example, each housing extends in the direction of pumping, not only at the intermediate span section, but also along the rigid span arms, known as lateral arms.

[0024] According to one embodiment of this peristaltic pump, this or these housings are ribs. Advantageously, such ribs impart stiffness to the moving span (MS).

[0025] According to another embodiment of this peristaltic pump, said or at least one of said anti-creep devices is an elastic spring-forming element. Advantageously, this elastic element is an open elastic ring, which is received in a groove formed in the outer face of said bearing. For example, this open ring is made of spring steel. It has a straight circular cross-section. Alternatively, this elastic spring-like element could still be flat. For example, it could be a leaf spring.

[0026] More generally, this elastic spring-forming element has at its ends retaining or hooking devices to ensure that it is held in position in its housing.

[0027] This elastic spring-forming element is made of a material working in elastic deformation such as spring steel.

[0028] According to yet another embodiment of this peristaltic pump, said or at least one of said anti-finishing devices is a rigid rider bearing on the outer face of said bearing. More generally, this bracket must be rigid in the direction of the pump axis (separation of the housings). Its thickness can also be rigid, flexible, or even incorporate an elastic connection (spring / suspension). This rider, for example, is made of a plastic material.

[0029] Preferably, this rider is mounted in a removable manner to allow intervention on the span. As an example, each part of the housing includes an anchoring element that protrudes from the corresponding housing body to allow locking / unlocking in the jumper position.

[0030] This jumper connects the two housing parts by covering a portion of the outer surface of the intermediate carrying part.

[0031] The peristaltic pump may thus include one or more elastic elements and / or one or more riders.

[0032] According to yet another embodiment of this peristaltic pump, it includes at least one adjustment element to apply an adjustable constraint to the outer face of said intermediate bearing part and to ensure an adjustment of the deformation of the latter. Preferably, this anti-creep device being a rider, said rider carries a screw such as a micrometer screw, the free end of which, passing through the body of said rider, bears against the outer face of the intermediate bearing part.

[0033] Adjusting the position of the screw allows a variable stress to be exerted on this outer face of the intermediate bearing part.

[0034] Of course, and alternatively, the rider can be devoid of an adjustment element and thus provide a determined constraint.

[0035] According to yet another embodiment of this peristaltic pump, comprising a rotor rotating around said main axis of said pump, said peristaltic pump includes an electric motor to drive said rotor in rotation, this electric motor being chosen from a stepper motor, a direct current motor or an alternating current motor, possibly with epicyclic reducers.

[0036] According to yet another embodiment of this peristaltic pump, the moving part is removable and can be fixed to the housing by simply snapping the guide elements onto the corresponding tracks of the housing. The movable section can therefore be easily removed to allow for the installation or replacement of the deformable tube.

[0037] According to yet another embodiment of this peristaltic pump, when the outlet-side lateral rider is adjusted by the screw to increase the arm's displacement towards more clamping, the tube is more constrained, which increases the possibility of obtaining a higher pressure.

[0038] The present invention also relates to a method of managing a peristaltic pump as described above, an adjustment element exerting a constraint on the outer face of the intermediate bearing part by determining two portions of the intermediate bearing part on either side of this adjustment element, the guide element(s) placed at the free end of one of the rigid lateral arms of said bearing are slid along the corresponding tracks of the housing to deform the corresponding portion of the intermediate bearing part while leaving the other rigid bearing arm fixed so as to leave the other portion of the intermediate bearing part unchanged.

[0039] Of course, this movement of only one of the lateral reach arms can be carried out on both the intake and discharge sides of the peristaltic pump.

[0040] The adjusting element is thus arranged to exert a constraint on the outer face of the intermediate bearing portion, defining two independent portions of the intermediate bearing portion on either side of this adjusting element. For example, this adjusting element may be a bracket and / or the free end of a screw, such as a micrometer screw, carried by this bracket.

[0041] For purely illustrative purposes, it will be understood that the free end of a screw locally constrains the intermediate bearing part, the deformation of a portion of this intermediate bearing part, placed on one side of the free end of the screw in the pumping direction, by the displacement of the corresponding lateral bearing arm, does not propagate to the other portion of the intermediate bearing part placed on the other side of the free end of the screw.

[0042] According to one embodiment of this method of managing a peristaltic pump, this adjustment element is placed at the apex of said peristaltic pump to determine two portions of intermediate part of substantially equal span on either side of this adjustment element.

[0043] According to another embodiment of this method of managing a peristaltic pump, detecting a depression on the intake side of said pump, the guide element(s) placed at the free end of the single rigid lateral arm, placed at the inlet of the pump, i.e. on the intake side, are slid so as to eliminate the sealing of the portion of the deformable tube placed on the intake side, when it is crushed by the rollers of said pump, during the duration of this depression.

[0044] According to yet another embodiment of this method for managing a peristaltic pump, the deformable tube is chosen beforehand so that its hardness is higher or lower than the range of hardness values ​​required to ensure the nominal sealing rating of said pump

[0045] As an example, the hardness of the tube being greater than the maximum hardness value provided by the manufacturer to ensure the nominal sealing dimension of the pump, this deformable tube exerts a counter-force allowing an adjustment of the crushing applied to this deformable tube.

[0046] The present invention further relates to a computer-readable medium comprising a set of software instructions which, when executed by a processor, allow certain steps of the peristaltic pump management process to be implemented as described above. Of course, the term "computer" refers to any programmable device.

[0047] Alternatively, it could still be a computer program that could be downloaded from a communication network and / or recorded on a computer-readable medium and / or is executable by a processor such as a processor embedded on said peristaltic pump, the movement of said micrometer screw and / or the ends of said rigid lateral arms along said tracks being motorized.

[0048] Furthermore, the movable reach (MR) of the invention advantageously allows the use of deformable tubes having different diameters. It adapts naturally to the deformable tube mounted in the peristaltic pump. Brief description of the drawings

[0049] Other advantages, purposes and special features of the present invention will become apparent from the following description, given for explanatory purposes and in no way as a limitation, with reference to the accompanying drawings, in which: Fig. 1

[0050] [Fig.1] is a schematic representation of a peristaltic pump according to a first embodiment of the present invention; Fig. 2

[0051] [Fig.2] is an enlarged and partial view of the peristaltic pump of [Fig.1] showing the apex of this pump with the positioning of the rider and the micrometer screw; Fig. 3

[0052] [Fig.3] is a top view of the peristaltic pump of [Fig.1] showing the received bearing between the two body parts of the housing, the elastic open ring housed in a groove of the outer surface of the bearing and the rider and its micrometric screw; Fig. 4

[0053] [Fig.4] is a bottom and perspective view of the reach of the peristaltic pump of [Fig.1]; Fig. 5

[0054] [Fig.5] is a schematic representation of a peristaltic pump according to a second embodiment of the present invention; Description of the implementation methods

[0055] The drawings and description below contain, essentially, elements of a definite nature. They may therefore not only serve to better understand the present invention, but also contribute to its definition, if necessary.

[0056] First of all, it should be noted that the figures are not to scale.

[0057] Figures 1 to 4 schematically illustrate a peristaltic pump 10 according to a first embodiment of the present invention.

[0058] This peristaltic pump 10 comprises a housing 11 which is formed by two housing body parts assembled together by defining a space to receive a movable bearing 12. These housing body parts 11 are here obtained by molding a plastic material.

[0059] It also includes a deformable tube (not shown) for transporting a liquid. This deformable tube is made of an elastomer material.

[0060] The peristaltic pump 10 comprises a rotor carrying three freely rotating rollers, the rotor being driven in rotation by an epicyclic geared motor (not shown). These rollers are regularly distributed around the periphery of the rotor, each roller being thus angularly spaced from its neighbor by an angle of 120°.

[0061] The inner face of the movable bearing 12 forms a support against which the deformable tube is crushed by the rollers to ensure the sealing of this tube and to ensure the movement of the liquid received in it.

[0062] This movable span 12 made in one piece from a plastic material, thus comprises an inner face 13 and an outer face, an intermediate span part from which rigid span arms 14, 15 extend on either side of it.

[0063] When the movable bearing 12 is in position on the frame of the peristaltic pump, these rigid bearing arms 14, 15 are placed laterally to a main axis of the pump determined by the motor shaft so that these bearing arms 14, 15 are usually called "lateral bearing arms".

[0064] These lateral arms of reach 14, 15 are here straight but they could of course take any other shape such as bent, in particular to take account of the space available in the pump frame.

[0065] Since this intermediate bearing part is deformable, the inner face 13 of this intermediate bearing part has a semi-cylindrical symmetry around an axis coinciding with the main axis of this pump.

[0066] The free end of each of these lateral arms of reach 14, 15 has bosses 16 extending laterally from them, which are able to slide along corresponding guide tracks 17 provided on the housing body 11.

[0067] Since the movements of the free ends of the lateral arms 14, 15 along these upstream and downstream guide tracks 17 are thus constrained, the intermediate part of the bearing is deformed. More specifically, the radius of its inner face 13 of the movable bearing 12 is modified while leaving the axis of the intermediate inner face 13 coincident with the main axis of the peristaltic pump 10.

[0068] The outer face of the movable bearing 12 has grooves 18 extending in the pumping direction, in one of which is placed an open elastic ring 19 bearing on the movable bearing 12 not only in its intermediate part but also on a part of the lateral arms 14, 15 of the bearing. This open elastic ring 19 is made of spring steel.

[0069] The peristaltic pump 10 also includes a rider 20 carrying a micrometer screw 21 whose shank can pass through the body of the rider so that the free end of this screw is placed in projection from the inner face of the rider 20. This rider / screw assembly is disposed at the apex of the peristaltic pump.

[0070] The body of the jumper 20 has a U-shaped form whose arms are bent so that the ends of the jumper 20 come into contact with projections 22 formed on the outer faces of the two parts of the housing body 11 for locking the jumper in position.

[0071] The lower face of the rider 20 which spans the space separating the two parts of the housing body 11 in which the movable bearing 12 is placed, thus comes to rest on the outer face of the intermediate part of the bearing, also constraining the latter.

[0072] The purpose of the rider 20 and the open elastic ring 19 is to prevent deformation of the intermediate bearing portion in order to preserve the seal of the deformable tube when it is crushed by the rotor rollers

[0073] In addition, the free end of the micrometer screw 21 can be advantageously moved to bear against the outer face of the intermediate bearing part and by further movements allow a fine adjustment, or even adjustable, of the stress applied to this outer face of the intermediate bearing part.

[0074] Thus, not only can the inner surface of the intermediate span be deformed by the displacement of the ends of the lateral span arms 14, 15 along the tracks 17 upstream and downstream of the housing, but it can also be deformed in a finer way, by moving the micrometer screw 21 towards the main axis of the peristaltic pump.

[0075] Fig. 5 is a schematic representation of a peristaltic pump 50 according to a second embodiment of the present invention.

[0076] The elements of the peristaltic pump 50 illustrated in [Fig.5] and bearing the same references as those illustrated in [Fig.1] to 4, represent the same objects, which will not be described again below.

[0077] The peristaltic pump 50 of [Fig.5] differs from that illustrated in [Fig.1] to 4 in that it has two assemblies of rider / screw 20, 21 mounted on the housing at the ends of the lateral arms 14, 15 of reach to act directly on these lateral arms.

[0078] Adjusting the constraint applied by each of these assemblies on the moving span allows the arms of span 14, 15 upstream and downstream, or even intake and discharge sides, to be decoupled, in order to manage the sealing differently between the intake and discharge ends of the peristaltic pump 50.

Claims

Demands

1. A peristaltic pump comprising a housing (11), a bearing surface (12) comprising an inner face and an outer face, said bearing surface (12) comprising an intermediate bearing surface from which bearing arms (14, 15) extend on either side thereof, this intermediate bearing surface being deformable, the inner face of this intermediate bearing surface having semi-cylindrical symmetry about an axis coinciding with a principal axis of said pump, said bearing arms (14, 15) being rigid, the free end of each of these lateral arms (14, 15) comprising at least one guide element (16), said housing comprising tracks (17) on which these guide elements are capable of sliding to constrain the displacement of the free ends of the rigid lateral arms so as to deform the intermediate bearing surface,the radius of its inner face being thus modified while leaving the axis of the intermediate inner face in coincidence with the main axis of said pump, characterized in that said bearing surface (12) being made of a plastic material, the outer face of said bearing surface (12) comprising one or more housings (18) extending in the pumping direction, at least one of these housings receiving an anti-creep device to prevent deformation of said intermediate bearing surface and / or said housing (11) comprising two housing body parts (11) between which said bearing surface is placed, said pump comprising at least one anti-creep device connecting said two housing body parts (11) bearing on the outer face of the bearing surface (12) to prevent deformation of said intermediate bearing surface.

2. Peristaltic pump according to claim 1, characterized in that said or at least one of said anti-creep devices is an elastic spring-forming element.

3. Peristaltic pump according to claim 2, characterized in that said elastic element is an open elastic ring (19), which is received in a groove (18) formed in the outer face of said bearing (12).

4. Peristaltic pump according to any one of claims 1 to 3, characterized in that said or at least one of said anti- devices finage is a rigid bracket (20) bearing on the outer face of said span (12).

5. Peristaltic pump according to claim 4, characterized in that said jumper (20) connects said two housing parts (11) by covering a portion of the outer surface of said intermediate bearing part.

6. Peristaltic pump according to any one of claims 1 to 5, characterized in that it comprises at least one adjustment element for applying an adjustable constraint to the outer face of said intermediate bearing part and ensuring an adjustment of the deformation of the latter.

7. Peristaltic pump according to claim 6, characterized in that said anti-creep device being a rider (20), said rider (20) carries a screw (21) whose free end passing through said rider (20) comes to bear against the outer face of the intermediate bearing part.

8. Peristaltic pump according to any one of the preceding claims, characterized in that, comprising a rotor rotating about said main axis of said pump, said peristaltic pump comprises an electric motor for driving said rotor in rotation, this electric motor being selected from a stepper motor, a DC motor or an AC motor, optionally with epicyclic reducers.

9. A method for managing a peristaltic pump according to any one of claims 4 to 8, characterized in that an adjustment element (20, 21) exerting a constraint on the outer face of the intermediate bearing portion by determining two portions of the intermediate bearing portion placed on either side of this adjustment element, the guide element(s) (16) placed at the free end of one of the rigid lateral arms of said bearing (12) are slid along the corresponding tracks (17) of the housing (11) to deform the corresponding portion of the intermediate bearing portion while leaving the other rigid bearing arm fixed so as to leave the other portion of the intermediate bearing portion unchanged.

10. A method for managing a peristaltic pump according to claim 9, characterized in that this adjustment element is placed at the apex of said peristaltic pump to determine two portions of intermediate of substantially equal range on both sides of this adjustment element.

11. A method for managing a peristaltic pump according to claim 9 or 10, characterized in that, upon detecting a depression on the inlet side of said pump, the guide element(s) placed at the free end of the single rigid lateral arm, located at the inlet of the pump, i.e. on the inlet side, are slid so as to remove the seal of said deformable tube located on the inlet side, when this portion of the tube is crushed by the rollers of said pump, during the duration of this depression.

12. A management method according to any one of claims 9 to 11, characterized in that said deformable tube is pre-selected so that its hardness is higher or lower than the range of hardness values ​​intended to ensure the nominal sealing rating of said pump.

13. A computer-readable medium comprising a set of software instructions which, when executed by a processor, enable the implementation of the method for managing a peristaltic pump according to any one of claims 9 to 12.