FR2871858A1 - PERISTALTIC PUMP COMPRISING A LOCKABLE REMOVABLE CASSETTE - Google Patents

Abstract

The peristaltic pump (2) comprises: - at least one cassette (6); and a support; It is arranged to allow the cassette to be unlocked from the support by pressing (90) on a main body (20) of the cassette.

Description

The invention relates to peristaltic pumps.

  Peristaltic pumps have the advantage of allowing the entrainment of a liquid through a conduit without a piece of the pump comes into contact with the liquid. It is thus possible to move sensitive liquids such as blood.

  EP-0 339 857 discloses a peristaltic pump comprising a support and cassettes removably mountable on the support next to each other. Each cassette comprises in particular a liquid transport pipe and locking means which hold the cassette firmly in position on the support knowing that the pump comprises movable rollers which generate indirectly on the cassette relatively high loads.

  To install the cassette, it is first engaged by one of its two branches with a support rod, then the cassette is rotated to engage the other branch with the other rod. Locking is exerted by pressing down on the cassette. Conversely, to unlock the cassette in order to remove, it solicits in rotation a flexible part, which allows to release the engagement of the cassette with respect to the second rod for its release.

  However, this mode of unlocking involves the user a movement rather unnatural and uncomfortable.

  An object of the invention is to facilitate the unlocking of the casette by the user.

  For this purpose, there is provided according to the invention a peristaltic pump comprising: - at least one cassette; and - a support; the pump being arranged to enable the cassette of the support to be unlocked by pressure on a main body of the cassette.

  Thus, the unlocking of the cassette is effected by simply pressing on it, which makes this unlocking particularly simple and fast to execute by the user. It is also a natural movement.

  The pump according to the invention may also have at least any of the following characteristics: the pressure is exerted in the same direction and the same direction as placing the cassette on the support, preferably towards the low; - It is arranged to allow to lock the cassette on the support by pressure on the body; it is arranged so that the pressure for locking and the pressure for unlocking are exerted in the same direction and in the same direction; it comprises a ramp and a follower arranged to lock and unlock the cassette according to the position of the follower on the ramp; - the follower is mobile in a dwelling and permanently retained in the dwelling; - The follower is movable to slide in a housing; - The follower is rotatable in a housing; the follower is rotatable in a housing around an axis perpendicular to a direction of sliding of the follower; it includes means for returning the follower; - It is arranged so that the ramp can be traveled in one direction by the follower; the ramp has a non-constant depth in a direction perpendicular to a path of the follower; the ramp has a locking zone arranged to extend under the follower in the vertical direction; the ramp has an arrival zone and a departure zone respectively extending upstream and downstream of the locking zone with reference to a path of the follower, and having different depths in a direction perpendicular to the path of the follower; it is arranged so that one and the same zone of the ramp serves as input and output for the follower; the ramp and the follower extend on lateral faces of the cassette and the support; - The ramp is part of the cassette and the follower is part of the support; and the cassette comprises a first part able to be engaged on a first part of the support and a second part able to be brought closer to a second part of the support at the end of the engagement.

  It is also provided according to the invention a method for unlocking a cassette of a support in a peristaltic pump in which pressure is exerted on a body of the cassette.

  Other features and advantages of the invention will become apparent in the following description of a preferred embodiment given by way of non-limiting example with reference to the accompanying drawings in which: FIGS. 1 and 2 are perspective views of FIG. a pump according to a preferred embodiment of the invention respectively illustrating the cassette in the disassembled state and in the assembled state; - Figure 3 is an axial sectional view along the III-III plane of the pump of Figure 2; FIG. 4 is a perspective view illustrating the cassette of FIG. 2 and the parts of the head which retain it; FIG. 5 is a perspective view of the cassette of FIG. 4; FIG. 6 is a view on a larger scale of the ramp of the cassette of FIG. 5; - Figures 7 to 11 are partial perspective views illustrating the different phases of the locking and unlocking at the follower and the ramp in the pump of Figure 2; and - Figures 12 and 13 are two side views showing the longitudinal displacement of the follower.

  FIGS. 1 to 13 show a preferred embodiment of a pump according to the invention. The peristaltic pump 2 comprises a pump head 4 and several cassettes 6. Only one cassette has been shown in the figures. The different cassettes are identical to each other.

  The head comprises two main front walls 8 and rear 10 each having a rectangular shape and extending parallel to one another, facing one another and at a distance from one another. The two walls form between them a space 12 serving as a receptacle for the cassettes extending parallel to each other, as will be seen below. The pump head comprises a rotating body 14 carrying rollers or rollers 16 which are here in number of 8. The rollers are uniformly and symmetrically arranged around a central axis 18 of the crew which constitutes its axis of rotation. The axes of the rollers are located on the same circle.

  The cassette comprises a main body 20 and a hose or flexible conduit 22. The body includes two branches 24 giving it a general shape of U reversed. In the free end regions of the branches are provided notches 26 in which are received two sections of the pipe 22. A median portion of the pipe extending between these two sections bears against a median lower edge of the cassette. This lower edge has a curved hollow shape. This portion of the pipe 22 is intended to bear on the rollers 16 during the rotation thereof. Following the principle of a peristaltic pump, when the crew 14 is rotated, the rollers exert a pressure on the pipe during their movement along it to cause pumping of the liquid through the pipe at level of its median section.

  The cassette 6 comprises in the present example a support piece 30 whose lower edge constitutes the aforementioned edge against which the pipe 22 extends. This part is better visible in FIG. 3 where a part of a wall of the cassette has been removed. The support 30 is slidably movable in the body 20 in the vertical direction and is biased down towards the pipe by return means such as a spring 32. Means are provided for adjusting the return force thus exercised, means which comprise for example a control button 34 emerging from an upper edge of the body 20. It is therefore possible to adjust the pressure exerted by the spring 32 on the pipe, which is itself supported on the rollers .

  Naturally, we only describe here the pump head knowing that the pump itself comprises other members, such as crew drive means 14, control means, etc. which are of a classical type.

  The head 4 comprises means for supporting the cassettes in the receptacle 12. These means comprise two longitudinal members 40, 42 extending from one to the other of the walls 8, 10 parallel to the axis 18. This axis is interposed between the two longitudinal members. The two longitudinal members extend in the same plane as the axis 18.

  As seen particularly in Figures 3 to 5, one of the two branches 24 of the cassette 6 has its end shaped as a hook 44 having a lug extending on the outer side face of the branch. The spar 42 comprises for each cassette location 6 an orifice 46 extending on an inner side face of the spar. The orifice 46 is intended to receive the hook 44 so as to retain the corresponding branch against its upward movement. The body 20 of the cassette 6 is also supported against a vertex of the spar by means of a shoulder 48 of the same branch.

  To mount the cassette on the head 4, the cassette 6 is brought vertically downwards into the receptacle 12, but with care to incline it so as to be able to introduce the hook 44 into the orifice 46. Once this commitment has been made, In this case, the cassette 6 is tilted so as to bring the other leg 24 closer to the corresponding spar 40. The cassette 6 is then locked in position by means of the elements which will now be described.

  For each of the cassette locations, the spar 40 comprises a follower 50 and a ramp 52 intended to cooperate with the follower 50.

  The follower 50 is in particular represented in elevation in FIGS. 7 to 13. It essentially comprises an elongate body of cylindrical shape, the median portion 51, however, having a rectangular parallelepipedal shape whose four peripheral faces are perpendicular to one another and parallel to each other. to the main axis of the follower 50. The follower 50 has an outer end 54 extending out of the spar 40. It also has an inner end 56 extending inside the spar 40. This end has a shape of half ball, the equatorial plane of the sphere constituting the inner face of the head being contiguous to the body. The outer face of the head thus has a hemisphere shape.

  The spar 40 comprises for each follower 50 a housing 60 of elongate shape. This housing 60 is provided so that the follower 50 is free to slide in the housing 60 in the longitudinal direction of the follower 50. The spar 42, however, comprises a retaining piece 63 having a flat shape with a cut open fork upwards in which is engaged the portion of the body extending between the portion 51 and the head 56 to form for the latter a stop preventing the total output of the follower 50 out of the housing 60.

  The housing 60 is also shaped so that the follower 50 is free to rotate in the housing about an axis 64 illustrated in particular in Figures 11 and 13 and extending in the vertical direction. This axis is therefore in particular perpendicular to the sliding direction of the follower 50. This axis extends in the plane of the part 61 at the fork being defined by the latter. The middle portion 51 of the follower 50 guides the latter during its movements in its housing 60.

  The spar 40 further comprises a return piece arranged in this case in the form of a flat elastic lamella 66 extending opposite the head and urging the spherical face thereof to push the follower 50 out of its housing , that is to say in the direction of the cassette. In the present example, the blade 66 is rotatable about a lower axis 62 perpendicular to the axis 64 and the longitudinal direction of the follower 50, as well as the plane of the drawing in Figure 12. In this example , the retaining piece 63 and the strip 66 are formed by cutting and folding a sheet. They therefore form a single piece.

  With reference to FIGS. 5 and 6 in particular, the ramp 52 extends on an external face of the branch 24 of the cassette intended to come opposite the follower 50. This face is hollowed out so that the ramp 52 is intended to guide and to urge the outer end 54 of the follower 50 as well by means of the faces of the ramp facing the follower 50 and visible in particular in elevation in FIG. 6 by means of the faces perpendicular to the latter and having generatrices for the essential parallel to the longitudinal direction of the follower.

  With reference to FIG. 6, the ramp comprises a zone 70 which acts as both an entry zone and an exit zone for the follower 50. This zone is contiguous with the lower end 72 of the branch 24.

  Above a median portion of this zone, extends a relief 74, projecting from this zone 70 in the direction of the follower.

  The ramp 52 comprises on the right of the relief 74 and above the zone 70 in Figure 6 an inlet duct 76 extending in the vertical direction.

  The ramp 52 has, following this conduit, an arrival curve 78 to the left including a downwardly facing bearing face 80 in the form of a cylinder sector.

  In the ramp 52 follows this turn a locking or retaining zone 82 extending above the relief 74 and comprising in particular a bearing surface 84 in the form of an upwardly facing cylinder sector.

  Following the zone 84, the ramp comprises a departure turn 86 to the left having in elevation in FIG. 6 the same shape as the arrival curve 78. This turn is also associated with a bearing face 88 in cylinder sector and facing down.

  The centers of curvature of the faces 80 and 88 are located below these faces, unlike that of the face 84 which is located above the face.

  Following the departure turn, there is an outlet duct 90 which forms the junction between this turn and the exit zone 70.

  The relief 74 has a lower bearing face 92 oriented downwards and to the right in FIG. 6. This flat face extends above the follower 50 in the rest position and tends to orient it towards the duct. input 76 when this face comes into contact with the follower.

  In addition, the inlet duct 76 has a bottom face extending opposite the follower 50 of flat shape and oriented slightly downwards. Thus, when the follower traverses this face, it is pushed into its housing towards the strip 66. This inclination is particularly visible in Figure 8.

  The bottom face of the arrival curve 78 is flat and vertical. The leading edge of this face 78 has a depth offset with respect to the output edge of the bottom face of the inlet duct 76 so as to prevent the follower 50 from passing from the arrival curve 78 to the duct Similarly, there is a depth offset between the holding zone and the arrival turn 78 so that the follower 50 can pass from the arrival bend to the holding zone without being able to follow the opposite path. Finally, there is a similar gap between the bottom face of the holding zone 82 and the bottom face of the starting turn 86 so that the follower 50 can pass from the holding zone to the starting turn without being able to follow the opposite path .

  These three offsets are visible in particular in FIG.

  It will be noted that the two downwardly facing cylindrical faces 80 and 88 of the entry and exit turns are joined by one of their edges so as to form an edge. This ridge, in cooperation with the depth offset between the arrival turn 78 and the holding zone 82, guides the follower from the holding zone to the starting turn 86.

  The bottom faces of the arrival turn 78, the holding zone 82 and the starting turn 86 are therefore arranged in terms of depth in the manner of steps that the end 54 of the follower 50 can descend in passing. from turn 78 to the holding zone 82 and then to the turn 86. The inlet conduit 76 allows the follower in the zone 70 to arrive directly at the highest step constituted by the arrival curve 78.

  With reference to FIGS. 7 to 11, the operation of the mechanism for locking and unlocking is therefore the following.

  When the cassette is in the position of FIG. 4, in order to proceed with locking, the user biases the body of the cassette, for example from its upper face, in the vertical direction downwards by exerting a pressure 90. This action has the effect of bringing the face 92 of the relief 74 into contact with the follower 50. It follows that the follower 50 which initially extends under and away from this face 92 is guided in the direction of the inlet duct 76.

  FIG. 7 illustrates the support and the cassette when the follower having left the zone 70 traverses the inlet duct 76. It is therefore urged by the latter towards the strip 66 against this latter. .

  In addition, in order to follow the inlet conduit 76, the follower 50 has rotated slightly to the right.

  As the pressure of the user continues on the cassette, the follower leaves the inlet duct 76 and arrives in the arrival curve 78, as illustrated in FIG. 2. The face 80 then forms a stop for the follower which marks for the user the end of the race towards the bottom of the cassette.

  Intuitively, the user then releases his pressure 90 on the cassette. Knowing that this pressure was exerted against the pipe 22 resting on the rollers, the elasticity of the pipe tends to move the branch 24 upwards. This has the effect, given the configuration of the ramp, to accommodate the follower 50 in the holding zone 82 and to bear against the face 84. With this support, the cassette is limited in its race to the top. It is then in locked operational position.

  To unlock the cassette, the user performs the same actions, which however have different effects. Thus exerting a new pressure 90 on the top of the cassette, this pressure has the effect of moving the follower 50 from the retaining zone 82 to the starting curve 86. The bearing of the follower against the face 88 marks the limit of run of the cassette down for the user, which intuitively releases its pressure.

  The elasticity of the pipe, again, then tends to raise the cassette, causing the follower to move towards the outlet duct 90 and then the zone 70.

  The user can then rotate the unlatched cassette away from the spar 42 branch 24 and released, then separate the hook 44 of the spar 42 to remove the cassette support.

  It will be observed that during its movement in the zones 78, 82 and 86, the follower 50 gradually slides out of its housing to go from the configuration of FIG. 12, which is essentially retracted, to the configuration of FIG. . Similarly, during the same movement, the follower rotates about the axis 64. When it is housed in the retaining zone 82, the follower is in the upright position, that is to say parallel to the pipe. When it arrives in the turn 86, the follower 50 has made a rotation to the left which it keeps until exiting the outlet duct 90. It resumes a straight position once arrived in the zone 70.

  The invention therefore allows the user to lock the cassette on the support by means of a simple pressure on the top of the cassette. The same action then allows the user to unlock the cassette. These actions can therefore be performed simply and quickly and, if necessary, following one another or even simultaneously for several cassettes of the pump. Note that these operations are performed without any contact of the user with the tube. These locking and unlocking actions which involve the elasticity of the pipe nevertheless define stroke limits which avoid over-stressing the pipe, both during maneuvers and when the cassette is in the operating position on the pump head. In particular, there is no risk that the pipe undergoes excessive stress during these maneuvers. This is particularly important since the service life of these hoses, which are strongly affected by the operation of the pump, can be considerably reduced when subjected to excessive stress.

  Of course, we can provide many modifications of the invention without departing from the scope thereof.

  In particular, it will be possible to modify the configuration of the ramp and the follower. It can be provided that the follower extends on the cassette and the ramp on the support.

Claims (19)

  A peristaltic pump (2) comprising: - at least one cassette (6); and a support (4); characterized in that it is arranged to unlock the pressure support cassette (90) on a main body (20) of the cassette.   2. Pump according to the preceding claim, characterized in that it is arranged so that the pressure (90) is exerted in the same direction and the same direction as placing the cassette (6) on the support, preferably down.   3. Pump according to any one of the preceding claims, characterized in that it is arranged to allow locking the cassette (6) on the support by pressure (90) on the body (20).   4. Pump according to the preceding claim, characterized in that it is arranged so that the pressure (90) for locking and the pressure (90) for unlocking are exerted in the same direction and in the same direction.   5. Pump according to any one of the preceding claims, characterized in that it comprises a ramp (52) and a follower (50) arranged to lock and unlock the cassette (6) depending on the position of the follower on the ramp .   6. Pump according to the preceding claim, characterized in that the follower (50) is movable in a housing (60) and permanently retained in the housing.   7. Pump according to any one of claims 5 or 6, characterized in that the follower (50) is slidably movable in a housing (60).   8. Pump according to any one of claims 5 to 7, characterized in that the follower (50) is rotatable in a housing (60).   9. Pump according to any one of claims 5 to 8, characterized in that the follower (50) is rotatable in a housing (60) about an axis (64) perpendicular to a direction of sliding of the follower ( 50).   10. Pump according to any one of claims 5 to 9, characterized in that it comprises means (66) for returning the follower (50).   11. Pump according to any one of claims 5 to 10, characterized in that it is arranged so that the ramp (52) can be traversed in one direction by the follower (50).   Pump according to any one of claims 5 to 11, characterized in that the ramp (52) has a non-constant depth in a direction perpendicular to a path of the follower (50).   13. Pump according to any one of claims 5 to 12, characterized in that the ramp (52) has a locking zone (82, 84) arranged to extend under the follower (50) in the vertical direction.   14. Pump according to any one of claims 5 to 13, characterized in that the ramp (52) has an arrival zone (78) and a departure zone (86) respectively extending upstream and downstream of the locking zone (82) with reference to a path of the follower (50), and having different depths in a direction perpendicular to the path of the follower (50).   15. Pump according to any one of claims 5 to 14, characterized in that it is arranged so that a same zone of the ramp (70) serves as input and output for the follower.   16. Pump according to any one of claims 5 to 15, characterized in that the ramp (52) and the follower (50) extend on side faces of the cassette (6) and the support (4).   17. Pump according to any one of claims 5 to 16, characterized in that the ramp (52) is part of the cassette (6) and the follower (50) is part of the support (4).   18. Pump according to any one of the preceding claims, characterized in that the cassette (6) comprises a first portion (44) adapted to be engaged on a first portion (42) of the support, and a second portion (52) apt to be brought closer to a second part (40) of the support at the end of the engagement.   19. A method for unlocking a cassette (6) of a support (4) in a peristaltic pump (2), characterized in that a pressure (90) is exerted on a body (20) of the cassette (6).