Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
  • F04B43/1253—Machines, pumps, or pumping installations having flexible working members having peristaltic action by using two or more rollers as squeezing elements, the rollers moving on an arc of a circle during squeezing
  • F04B43/1276—Means for pushing the rollers against the tubular flexible member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action

Definitions

• the present invention relates to a peristaltic pump cassette making the final occlusion of its tube during the first introduction of the motor axis.
• Peristaltic pumps allow obtaining a regular and controllable flow. They are commonly used, in particular in the medical field, for example for controlling injections.
• Peristaltic pumps often include a cassette intended to cooperate with the axis of a motor which produces the friction drive of the mobile elements.
• Such a cassette includes a housing, a deformable tube and rotating rollers.
• the deformable tube forms a loop in a plane, applied to a bearing surface of the housing by rotary rollers.
• FR-A-2,644,212 relates to a cassette for peristaltic pump with deformable tube and the pump provided with such a cassette.
• the cassette has a housing which comprises, in the vicinity of each of its ends, a cylindrical raceway against which are applied and roll satellites which crush the deformable tube located between the two raceways.
• the cassette described and illustrated is of a simple and robust construction.
• French patent application FR-A-2,644,522 relates to a peristaltic pump with a deformable tube comprising, inside the casing, independent deformable tube arcs, which ensures a reduction in the fluctuations of the instantaneous flow rate.
• the pump has a small footprint.
• a cassette released from its engine block, is capable of allowing the flow of a liquid in the tube which passes through it, which can in certain cases present risks.
• an infusion liquid can then be injected under uncontrolled conditions, no longer corresponding to the prescription.
• peristaltic pump cassettes in which the deformable tube is placed in compression and obliterated as soon as the pump is assembled.
• this compression of the tube at a determined point, throughout the period of time elapsing between assembly and use of the pump, is liable to cause permanent deformation of the tube prejudicial to its subsequent use.
• the object of the present invention is therefore to propose a peristaltic pump cassette in which the tube is permanently obliterated after first use, regardless of its subsequent configuration and its location in relation to the engine block.
• the invention relates to a peristaltic pump cassette intended to cooperate, during its use, with an engine block by a drive shaft comprising: - a housing having a tube bearing surface,
• the rollers before the first use, have a radial position in which the tube is not closed; during the first use, they are radially displaced by an introduction of the drive axis, closing the tube; after use, the rollers are held in a radial position ensuring the obturation of the tube.
• the housing contains blocking means preventing the removal of at least part of the drive shaft after its first introduction;
• the cassette comprises an elastic member linked to the housing, released by the introduction of the drive axis and maintaining at least one of the rollers in a radial position ensuring the obturation of the tube;
• the rollers are free and each have a drive revolution surface delimited by two bases, and each comprise at least one cylinder on one of their bases;
• the housing comprises a disc, approximately perpendicular to the drive axis, in the vicinity of the rollers, this disc having an elastic finger supported on the base of the cylinder of one of the rollers before the first introduction of the axis drive, released during the introduction of this axis, and coming to bear against the surface of revolution of the cylinder, maintaining at least one roller in a radial position ensuring the obturation of the tube;
• the disc is a plastic disc in which the elastic finger is formed
• the elastic finger carries a concentric stop of the drive axis capable of cooperating with the roller cylinder;
• the stopper covers an angle greater than 120 °
• the stopper covers an angle of approximately 132 °;
• the rollers have hubs
• the cassette includes separators on which the rollers are fixed by their hubs, said separators having first housings in which the hubs are placed before the first introduction of the drive axis, and second housings more eccentric than the first, and separated from them by an elastic stop, the first introduction of the motor axis into the cassette producing irreversible displacement of the hubs from the first housings to the second.
• FIG. 1 is a general representation of a peristaltic pump cassette in the position of use on an engine block, seen in perspective;
• - Figure 2 is the representation of the same assembly seen from above;
• - Figure 3 is a top view representation of a cassette according to the invention without its cover before any use;
• FIG. 4 is the sectional representation AA of the cassette of Figure 3;
• FIG. 5 and 6 are the representations corresponding to Figures 3 and 4, when the cassette cooperates with the drive axis;
• FIG. 9 represents the implementation of the invention in a cassette comprising separators before the first use
• the cassette 1 is placed, during its use, on the engine block 2 which has a housing provided for this purpose.
• the buttons 6 and 7 allow the dissociation of the cassette 1 from the engine block 2 and contribute to the safety necessary for this operation.
• the tubes 8 and 9 are respectively the inlet and outlet tubes of the pump.
• the tube 8 can, for example, be connected to an infusion reservoir, while the tube 9 is connected to an injection needle.
• the deformable tube 11 forms an approximately planar loop, supported by its outer surface on a bearing surface 12 provided for this purpose in the housing 13 of the cassette 1 of the peristaltic pump.
• rollers 14, of variable number, represented here three in number, have a shape of axis revolution 21 and are placed inside the loop formed by the deformable tube 11.
• the drive axis 15 parallel to the axis of revolution of the rollers, spreads them when it is introduced between them, causes them to compress the deformable tube 11 against the bearing surface 12 and ensures their drive by friction.
• a roller has an axis of revolution 21, two cylindrical surfaces 22, 23 in contact with the axis 30 and allowing the drive of the rollers 14 by this axis 30.
• a bearing surface 24 of axis 21, preferably in the shape of a barrel, that is to say with a convexity facing outwards, is intended to ensure compression on the deformable tube 11.
• the central element 25 results from the method of manufacturing the roller 14 and does not intervene directly in the device and the operation described here.
• the roller 14 is provided, at each of its ends, with a cylinder 26, 27, also of axis 21, of diameter smaller than the cylinders 22 and 23.
• the axis 21 of the rollers is of course parallel to the drive axis 30.
• the radial distance of the rollers is distance r, respectively designated by ri, r2, r3 in the various Figures.
• the peristaltic pump cassette has a housing
• the deformable tube 11 When the pump is mounted, the deformable tube 11 is connected to a tube guide 42, on which it is fixed by means of the male elements 43 and 44.
• the deformable tube 11 thus forms a loop, approximately planar, which is positioned inside the housing 40 and comes to bear on the bearing surface 12.
• the rollers 14 are then introduced inside the closed loop. Due to their diameter, they come into contact with each other and produce a slight deformation of the tube 11. By elasticity, the tube 11 pushes the rollers towards the center and produces their contact with each other.
• the tube 11 In the absence of the drive axis, the tube 11, as shown in section in Figure 4, is only partially deformed. Indeed, the respective dimensions of the housing and the rollers are determined in such a way that this tube 11 is not closed or obliterated.
• This compression causes the complete obstruction or obliteration of the tubing.
• this compression exerts an elastic force applying the rollers 14, more particularly their cylindrical zones 22, 23 on the drive axis 30.
• the pipe 11 Since the pipe 11 is no longer obliterated, it is capable of allowing the liquid it contains to circulate, for example when a pressure difference exists between the inlet pipe 8 and the outlet pipe 9.
• the housing 40 of the cassette comprises an elastic element, not shown, cooperating with the axis of rotation 30, so that the latter, once introduced in position in the cassette , can no longer be checked out. It may be, for example, an elastic finger fixed to the bottom of the housing and cooperating with a groove formed on the drive axis 30.
• the elastic tube 11 is definitively obliterated by the introduction of the axis of rotation 30 which is itself final.
• the drive axis 30 must be changed each time the cassette is changed.
• the motor shaft 32 integral with the engine block 2, then comprises a coupling member 31 ensuring the junction with the drive shaft 30.
• the housing 40 is equipped with a disk 50, positioned relative to the latter by notches 51, 52, and comprising an elastic finger 53, optionally equipped with a stop
• a flange 55 provided on the disc 50 contributes to its positioning relative to the housing 40.
• the stop 54 is concentric with the drive axis 30.
• rollers 14 are pushed, as indicated above, towards the outside of the cassette and allow the engagement of the stop 54 at the cylindrical part 27 roller 14, as shown in Figure 6.
• the cassette of the invention has only one disc placed in the vicinity of one of the roller bases 14.
• the angular dimension of the stop 54 is determined in such a way that, whatever the position of the rollers inside the cassette, at least one of them is supported on this stop and ensures, with the best security, the obliteration of the tube 11. This result is obtained with an angular stop 54 extending over an angle of at least 120 ° and preferably equal to approximately 132 °.
• the rollers are positioned at a distance ri from the drive axis 30.
• their radial position becomes r2 and when the latter is removed, the radial positio of the rollers 14 becomes r3.
• r2 is greater than ri e the displacement of the rollers in this position produces the complete obliteration of the deformable tube 11.
• r3 are also greater than ri and when the rollers 14 occupy the corresponding position, complete obliteration of the tube 11 is also carried out.
• r3 is slightly less than r2.
• Another embodiment of the invention is proposed in the case where the rollers have hubs 6 and are held by separators 61.
• the separator 61 then comprises, for each of the rollers 14, a first housing 62 corresponding to a first radial position r5 of the rollers, and a second housing 63 corresponding to a second radial position r6 of the rollers.
• first housings 62 and second housings 6 are separated by stops 64, 65 forming between them a space of dimension smaller than the diameter of the hub 60.
• This first and second housings thus form an end element of each arm 66 of the separator 61 deformabl when pressure is exerted by the hub 60. This deformation allows passage of the hub 60 from the first housing 62 to the second housing 63.
• the radial distance r6 of the second housing 63 is greater than the radial distance r5 of the first housing 62.
• the hubs 60 e rollers 14 When mounting the cassette, the hubs 60 e rollers 14 are placed in the first housings. During the introduction of the drive axis 3 between the rollers, it exerts a pressing force on the hubs 60, imposing their passage by elastic deformation from the end of the arms 66 to the second housings 63. During from the extraction of the drive axis 30, the elastic return force exerted by the deformable tube 11 is insufficient to produce the return of the hubs in the first housings 62.
• the drive axis 30 denotes the drive axis of the rollers as a material element, but also as defining its theoretical position, including when the pump is dissociated from its engine block, therefore that the axis is not physically present.

Applications Claiming Priority (3)

Publications (2)

Family

ID=9450028

Family Applications (1)

Country Status (8)

Families Citing this family (40)

Family Cites Families (8)

• 1993
  • 1993-08-06 FR FR9309749A patent/FR2708675B1/fr not_active Expired - Fee Related
• 1994
  • 1994-08-03 AU AU73873/94A patent/AU7387394A/en not_active Abandoned
  • 1994-08-03 EP EP94923774A patent/EP0712465B1/de not_active Expired - Lifetime
  • 1994-08-03 WO PCT/FR1994/000976 patent/WO1995004886A1/fr active IP Right Grant
  • 1994-08-03 DE DE69402428T patent/DE69402428T2/de not_active Expired - Fee Related
  • 1994-08-03 US US08/591,541 patent/US5655897A/en not_active Expired - Fee Related
  • 1994-08-03 JP JP7506249A patent/JP2723363B2/ja not_active Expired - Lifetime
  • 1994-08-03 CA CA002168854A patent/CA2168854A1/fr not_active Abandoned

Non-Patent Citations (1)

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