EP0484717B1 - Hose pump - Google Patents

Hose pump Download PDF

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Publication number
EP0484717B1
EP0484717B1 EP91117858A EP91117858A EP0484717B1 EP 0484717 B1 EP0484717 B1 EP 0484717B1 EP 91117858 A EP91117858 A EP 91117858A EP 91117858 A EP91117858 A EP 91117858A EP 0484717 B1 EP0484717 B1 EP 0484717B1
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EP
European Patent Office
Prior art keywords
hose
pump
slide
slides
return stroke
Prior art date
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Expired - Lifetime
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EP91117858A
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German (de)
French (fr)
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EP0484717A1 (en
Inventor
Hans Gerlach
Reinhard Knuth
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B Braun Melsungen AG
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B Braun Melsungen AG
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Publication of EP0484717A1 publication Critical patent/EP0484717A1/en
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    • 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
    • F04B43/08—Machines, pumps, or pumping installations having flexible working members having tubular flexible members
    • F04B43/082—Machines, pumps, or pumping installations having flexible working members having tubular flexible members the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism

Definitions

  • the invention relates to a hose pump of the type specified in the preamble of claim 1.
  • linear peristaltic pumps are often used as infusion pumps to deliver liquid from a reservoir to a patient's body.
  • the peristaltic pump has a tube that is inserted into the pump housing as an inexpensive, sterile, disposable item.
  • the hose is pressed off by a squeezing device, which has numerous sliders driven by a camshaft, which act cyclically on the pump hose in different phases and squeeze it out.
  • the hose has a resilience so that it widens again at this point when a slide is withdrawn.
  • a problem with such peristaltic pumps is that they cause a retraction phase in the medium on the return stroke of the last slide. This effect is caused by the fact that after the last slide is withdrawn, the inner volume of the hose that is now free is greater than the volume of media that has been added at this point in time. The widening hose creates suction and thus backflow. This withdrawal is particularly disadvantageous in the case of low delivery rates and increased back pressure, since there is a clear return delivery for a certain period of time. In the case of medical peristaltic pumps, this return delivery can have fatal consequences because blood can be drawn into the cannula through which the medication is to be delivered to the patient.
  • DE 31 04 873 A1 describes a device with which pulsations can be prevented in a peristaltic pump.
  • this device in addition to the pump slides, there are two further slides driven by the camshaft, the drive cams of which differ from those of the other slides.
  • the additional spools are controlled to produce an out-of-phase pulsation and build up pressure at times when the normal spools would cause reflux.
  • the media pressures, which are generated by the normal pump slide and the additional slide complement each other in such a way that an almost constant delivery pressure is achieved.
  • it is disadvantageous that a considerable amount of additional components is required, that the pump is enlarged in its structural dimensions and that there is also increased friction.
  • a finger pump is known from US Pat. No. 4,952,124, with which the problem of backflow is to be avoided or reduced by controlling at least two of the fingers provided in the central region of the pump length in such a way that the effective area becomes wider than the other fingers. This complicates the mechanical structure of the pump or requires a larger number of fingers.
  • additional slides are provided as gate valves.
  • the invention has for its object to provide a simple, effective and the pumping system not hindering or stressful measure to reduce the pulsation or withdrawal in a peristaltic pump.
  • the last slide in the conveying direction is controlled in such a way that it keeps the hose partially compressed even in the retracted state. While the remaining slides release the hose in the retracted position, so that the hose cross section can at least approximately return to the original state, the last slider is only between the closed position and a partial open position of the hose moved. The return stroke of the slide takes place only to such an extent that the hose cross section is opened to such an extent that there are no aerodynamic disadvantages. Because the last slide is only partially retracted, the volume released when the pump cycle begins again at the end of the pump area of the hose is reduced. The ratio between the volume released and the volume conveyed per unit of time is significantly reduced, ie improved, by this measure.
  • the delivery volume per pump cycle is not affected by the narrowing of the pump hose.
  • the delivery volume of the pump is defined during the time in which the first and the last slide compress the hose (at the same time). The volume in the hose is then driven forward and conveyed.
  • a return stroke limiting device which advantageously consists of a stop fixed to the housing, acts on the last slide.
  • Another advantage is that the control cam of the last slide can be designed in the same way as the control cam of the other slides. Of course, all of the camshaft control cams must be circumferentially offset from one another.
  • the peristaltic pump can therefore generally be constructed with the components of conventional peristaltic pumps, only a slot possibly having to be provided in the last slide, which allows the associated control cam of the camshaft to continue to rotate while this slide is held by the stop forming the return stroke limiting device .
  • the peristaltic pump 10 is mounted in a recess 12 in a front housing wall 11 of the housing of an infusion device. It consists of the rigid frame 13 with the counter bearing 14, the squeezing device 15 and the pressing device 16.
  • the frame 13 has a base part 17 and four rods 18 projecting therefrom.
  • the counter bearing 14 is attached via a joint, which is designed as a hinged door and can be attached to the other two rods 18 with a quick release.
  • a drive motor (not shown), which is fastened to the pump housing 21, drives via a reduction gear the camshaft 22 mounted in the pump housing 21.
  • the camshaft 22 consists of a shaft 23 with a hexagonal profile and cam disks 24 seated on this shaft, each of which has a hexagonal opening and thereby sits on the shaft 23 in a rotationally fixed manner.
  • Two cam disks 24 each form a double cam disk. Adjacent cam disks are circumferentially offset from one another by 30 ° on the shaft 23 and have an eccentricity of 2.5 mm, which results in a stroke of 5 mm with a full rotation of the cam disk.
  • Each of the cam disks 24 drives a slide 25.
  • the slides are guided in the pump housing 27 so that they can be moved longitudinally in lateral grooves and they run through slots 26 in the wall of the pump housing facing the counter bearing 14, a thickened head 27 being arranged at the end of each slide 25 .
  • the bearing play of the guide grooves for the slider 25 is selected so that the heads of adjacent slides just touch, but that tolerances of the slider or the heads do not add up.
  • the heads 27 of the slide are covered by a membrane 28 which is attached to the pump housing 21.
  • the pump housing 21 also has flanges 29 with which it is fastened to the housing wall 11 of the device housing.
  • the pump housing 21 is guided with sliding bushes along the rods 18, so that the frame 13 relative to the pump housing 21 or the crimping device 15 in Longitudinal direction of the rods can be moved.
  • the counter bearing 14 When the counter bearing 14 is in the closed position, it is a rigid component of the frame 13 and can be moved horizontally with the latter relative to the housing wall 11 or to the crimping device 15 fastened therein.
  • a spring device 33 consisting of at least one compression spring is supported on the rear side of the pump housing 21.
  • the spring device 33 is contained in a tube 34 which is connected to the pump housing 21 and which telescopically plunges into a tube 35 projecting rearward from the base part 17.
  • At the end of the tube 35 there is an adjusting device 36, which engages with a thread in an internal thread 37 of the tube 35 and presses with its end against the spring device 33.
  • the spring force of the pressing device 16 can be changed by rotating the adjusting device 36.
  • the spring device 33 engages centrally on the base part 17 and on the squeezing device 15, i.e. along the central axis of the crimping device.
  • a slider 38 is provided, which enables low-friction sliding of the two tubes 34 and 35 and which, together with the sliding bushes 32, ensures that the frame 13 is guided in a linearly displaceable manner without tilting relative to the squeezing device 15.
  • the hose 40 which runs vertically between the membrane 28 and the counterbearing 14, is squeezed out at least in every phase of the rotation of the camshaft 22 by at least one slide 25. Any tolerances of the pump and / or hose are compensated for by the pressing device 16, which causes the frame 13 together with the thrust bearing 14 against the squeezing device by the spring device 33 15, and thus driven against the slide 25.
  • a push button 39 is slidably arranged on the pump housing 21, which pushes against the membrane 28 and against the outlet region of the pump hose.
  • the push button 39 is coupled to a sensor (not shown) which detects the position of the push button 39 and thereby determines the output pressure of the pump.
  • the camshaft 22 controls the slide 25 so that the hose 40 is continuously compressed and squeezed by the heads 27, the compression progressing in the conveying direction, that is to say from right to left in the drawings of this exemplary embodiment.
  • the sliders act on the pumping area of the tubing in a section that encompasses 360 ° of the pumping cycle, i.e. the first and the last slide are controlled in phase.
  • Fig. 3 the state is shown that the first in the conveying direction and the last in the conveying direction slide 25 are both in the outermost advanced state.
  • the intermediate slides 25 are withdrawn to a greater or lesser extent, so that the volume V F enclosed in this area by the hose 40 represents the delivery volume which is enclosed on all sides at this moment and which is advanced in the delivery direction.
  • the heads 27 In the retracted position of the slide, the heads 27 assume a position which enables the hose to assume the undeformed (round) state.
  • the hose itself has its own resilience.
  • the last slide 25a in the conveying direction is generally designed in the same way as the other slides 25 and the cam disk 24a controlling it has the same shape as the other cam disks 24. It is different that a return stroke limiting device is provided which does not allow the slide 25a, withdraw as far as the other slides 25.
  • This return stroke limiting device consists of a stop 42 which is provided on the housing 21 and against which the head 27a of the slider 25a abuts during the retraction movement. This stop 42 is arranged so that the slider 25a in the extreme retracted position, that is, when its head 27a abuts the stop 42, takes up half the hose diameter (or a little more), as can be seen from FIG. 4.
  • the tube volume V 1 is also shown hatched, which is excluded from the release during the retraction movement of the slide 25 a and which contributes to the reduction or elimination of the back suction. If the slide 25a were to move back as far as the other slides, then the hose widening in this area would cause a backward suction.
  • a gap 43 is provided in the slide 25a, in which the cam disk 24a moves and which permits a longitudinal movement of the cam disk 24a with respect to the slide 25a. This achieves the required play of the camshaft in relation to the slide 25a.
  • the slide 25a is designed in the same way as the slide 25 and the cam disk 24a is designed in the same way as the cam disks 24.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • External Artificial Organs (AREA)
  • Details Of Reciprocating Pumps (AREA)

Abstract

The hose pump has a plurality of slides (25), which are driven by a camshaft, constantly compressing a hose (40). The final slide (25a) in the delivery direction is controlled in such a way that even in the retracted state it still keeps the hose partially compressed, which is achieved by a stop (42) which represents a return stroke limitation. Due to this return stroke limitation the hose volume freed at the start of a new pump cycle, which would otherwise lead to return suction, is limited. <IMAGE>

Description

Die Erfindung betrifft eine Schlauchpumpe der im Oberbegriff des Patentanspruchs 1 angegebenen Art.The invention relates to a hose pump of the type specified in the preamble of claim 1.

Im medizinischen Bereich werden häufig lineare Schlauchpumpen als Infusionspumpen verwendet, um Flüssigkeit aus einem Vorratsbehälter dem Körper eines Patienten zuzuführen. Die Schlauchpumpe weist einen Schlauch auf, der als preisgünstiger steriler Einmalartikel in das Pumpengehäuse eingesetzt wird. Der Schlauch wird durch eine Quetschvorrichtung abgedrückt, die zahlreiche von einer Nockenwelle angetriebene Schieber aufweist, welche zyklisch in unterschiedlichen Phasenlagen auf den Pumpenschlauch einwirken und diesen abquetschen. Der Schlauch besitzt eine Rückstellfähigkeit, so daß er sich bei einem Rückzug eines Schiebers an dieser Stelle wieder aufweitet.In the medical field, linear peristaltic pumps are often used as infusion pumps to deliver liquid from a reservoir to a patient's body. The peristaltic pump has a tube that is inserted into the pump housing as an inexpensive, sterile, disposable item. The hose is pressed off by a squeezing device, which has numerous sliders driven by a camshaft, which act cyclically on the pump hose in different phases and squeeze it out. The hose has a resilience so that it widens again at this point when a slide is withdrawn.

Ein Problem bei derartigen Schlauchpumpen besteht darin, daß sie bei dem Rückhub des letzten Schiebers eine Rückzugsphase im Medium verursachen. Dieser Effekt wird dadurch hervorgerufen, daß nach dem Zurückziehen des letzten Schiebers das jetzt freiwerdende Schlauchinnenvolumen größer ist als das zu diesem Zeitpunkt nachgeförderte Medienvolumen. Durch den sich wieder aufweitenden Schlauch entsteht ein Sog und somit ein Rückfluß. Dieser Rückzug ist besonders bei kleinen Förderraten und erhöhtem Gegendruck nachteilig, da für einen gewissen Zeitraum eine deutliche Rückförderung erfolgt. Bei medizinischen Schlauchpumpen kann diese Rückförderung verhängnisvolle Folgen haben, weil Blut in die Kanüle eingesaugt werden kann, durch die das Medikament dem Patienten zugeführt werden soll.A problem with such peristaltic pumps is that they cause a retraction phase in the medium on the return stroke of the last slide. This effect is caused by the fact that after the last slide is withdrawn, the inner volume of the hose that is now free is greater than the volume of media that has been added at this point in time. The widening hose creates suction and thus backflow. This withdrawal is particularly disadvantageous in the case of low delivery rates and increased back pressure, since there is a clear return delivery for a certain period of time. In the case of medical peristaltic pumps, this return delivery can have fatal consequences because blood can be drawn into the cannula through which the medication is to be delivered to the patient.

DE 31 04 873 A1 beschreibt eine Vorrichtung, mit der bei einer Schlauchpumpe Pulsationen verhindert werden können. Bei dieser Vorrichtung sind zusätzlich zu den Pumpenschiebern zwei weitere von der Nockenwelle angetriebene Schieber vorhanden, deren Antriebsnocken sich von denjenigen der anderen Schieber unterscheiden. Die zusätzlichen Schieber sind so gesteuert, daß sie eine gegenphasige Pulsation erzeugen und in denjenigen Zeiten, in denen die normalen Schieber einen Rückfluß verursachen würden, einen Druck aufbauen. Die Mediendrücke, die durch die normalen Pumpenschieber und die zusätzlichen Schieber erzeugt werden, ergänzen sich gegenseitig in der Weise, daß ein nahezu konstanter Förderdruck erreicht wird. Nachteilig ist jedoch, daß ein erheblicher Aufwand an zusätzlichen Bauelementen erforderlich ist, daß die Pumpe in ihren baulichen Abmessungen vergrößert wird und daß auch eine erhöhte Reibung auftritt.DE 31 04 873 A1 describes a device with which pulsations can be prevented in a peristaltic pump. In this device, in addition to the pump slides, there are two further slides driven by the camshaft, the drive cams of which differ from those of the other slides. The additional spools are controlled to produce an out-of-phase pulsation and build up pressure at times when the normal spools would cause reflux. The media pressures, which are generated by the normal pump slide and the additional slide, complement each other in such a way that an almost constant delivery pressure is achieved. However, it is disadvantageous that a considerable amount of additional components is required, that the pump is enlarged in its structural dimensions and that there is also increased friction.

Aus US 4 952 124 ist eine Fingerpumpe bekannt, mit der das Problem des Rückflusses vermieden oder vermindert werden soll, indem mindestens zwei der im mittleren Bereich der Pumpenlänge vorgesehenen Finger derart zusammen gesteuert werden, daß die Wirkfläche gegenüber den übrigen Fingern breiter wird. Dadurch wird der mechanische Aufbau der Pumpe komplizierter bzw. wird eine größere Anzahl von Fingern benötigt. In US 4 952 124 sind zusätzliche Schieber als Absperrschieber vorgesehen.A finger pump is known from US Pat. No. 4,952,124, with which the problem of backflow is to be avoided or reduced by controlling at least two of the fingers provided in the central region of the pump length in such a way that the effective area becomes wider than the other fingers. This complicates the mechanical structure of the pump or requires a larger number of fingers. In US 4 952 124 additional slides are provided as gate valves.

Eine mögliche Lösung des Problems würde darin bestehen, in dem Schlauch-Überleitungssystem ein Rückschlagventil anzuordnen. Hierdurch würde jedoch das Überleitungssystem, das aus Einmalartikeln besteht, verteuert werden. Es würden sich hohe Betriebsfolgekosten ergeben.One possible solution to the problem would be to place a check valve in the hose transfer system. However, this would make the transfer system, which consists of disposable items, more expensive. There would be high follow-up costs.

Der Erfindung liegt die Aufgabe zugrunde, eine einfache, wirkungsvolle und das Pumpsystem nicht behindernde oder belastende Maßnahme zur Verminderung der Pulsation bzw. des Rückzuges bei einer Schlauchpumpe anzugeben.The invention has for its object to provide a simple, effective and the pumping system not hindering or stressful measure to reduce the pulsation or withdrawal in a peristaltic pump.

Die Lösung dieser Aufgabe erfolgt erfindungsgemäß mit den im Patentanspruch 1 angegebenen Merkmalen.This object is achieved according to the invention with the features specified in claim 1.

Bei der erfindungsgemäßen Schlauchpumpe ist der in Förderrichtung letzte Schieber derart gesteuert, daß er auch im zurückgezogenen Zustand den Schlauch noch teilweise zusammengedrückt hält. Während die übrigen Schieber den Schlauch in der Rückzugsposition jeweils freigeben, so daß der Schlauchquerschnitt sich wenigstens annähernd auf den Ursprungszustand zurückstellen kann, wird der letzte Schieber nur zwischen der Schließposition und einer teilweisen Öffnungsstellung des Schlauchs bewegt. Der Rückhub des Schiebers erfolgt lediglich so weit, daß der Schlauchquerschnitt in einem Maße geöffnet wird, daß keine strömungstechnischen Nachteile auftreten. Dadurch, daß der letzte Schieber nur teilweise zurückgezogen wird, verkleinert sich das bei Neubeginn des Pumpzyklus am Ende des Pumpenbereichs des Schlauchs freiwerdende Volumen. Das Verhältnis zwischen freiwerdendem Volumen und nachgefördertem Volumen pro Zeiteinheit wird durch diese Maßnahme wesentlich verringert, d.h. verbessert. Ein weiterer Vorteil besteht darin, daß das Fördervolumen pro Pumpzyklus durch die Einengung des Pumpenschlauchs nicht beeinflußt wird. Das Fördervolumen der Pumpe wird während der Zeit definiert, in welcher der erste und der letzte Schieber den Schlauch (gleichzeitig) zusammendrücken. Das dann im Schlauch befindliche Volumen wird nachfolgend vorgetrieben und gefördert.In the hose pump according to the invention, the last slide in the conveying direction is controlled in such a way that it keeps the hose partially compressed even in the retracted state. While the remaining slides release the hose in the retracted position, so that the hose cross section can at least approximately return to the original state, the last slider is only between the closed position and a partial open position of the hose moved. The return stroke of the slide takes place only to such an extent that the hose cross section is opened to such an extent that there are no aerodynamic disadvantages. Because the last slide is only partially retracted, the volume released when the pump cycle begins again at the end of the pump area of the hose is reduced. The ratio between the volume released and the volume conveyed per unit of time is significantly reduced, ie improved, by this measure. Another advantage is that the delivery volume per pump cycle is not affected by the narrowing of the pump hose. The delivery volume of the pump is defined during the time in which the first and the last slide compress the hose (at the same time). The volume in the hose is then driven forward and conveyed.

Vorzugsweise wirkt auf den letzten Schieber eine Rückhubbegrenzungseinrichtung ein, die zweckmäßigerweise aus einem gehäusefesten Anschlag besteht. Dies hat den Vorteil einer sehr einfachen Ausführungsform, die keinerlei zusätzliche Bauteile oder Komponenten erfordert. Ein weiterer Vorteil besteht darin, daß der Steuernocken des letzten Schiebers in gleicher Weise ausgebildet sein kann wie die Steuernocken der übrigen Schieber. Natürlich müssen sämtliche Steuernocken der Nockenwelle umfangsmäßig gegeneinander versetzt sein. Die Schlauchpumpe kann daher generell mit den Komponenten üblicher Schlauchpumpen aufgebaut werden, wobei lediglich in dem letzten Schieber ggf. ein Schlitz vorzusehen ist, der es zuläßt, daß der zugehörige Steuernocken der Nockenwelle sich weiterdreht, während dieser Schieber durch den die Rückhubbegrenzungseinrichtung bildenden Anschlag festgehalten wird.A return stroke limiting device, which advantageously consists of a stop fixed to the housing, acts on the last slide. This has the advantage of a very simple embodiment that does not require any additional parts or components. Another advantage is that the control cam of the last slide can be designed in the same way as the control cam of the other slides. Of course, all of the camshaft control cams must be circumferentially offset from one another. The peristaltic pump can therefore generally be constructed with the components of conventional peristaltic pumps, only a slot possibly having to be provided in the last slide, which allows the associated control cam of the camshaft to continue to rotate while this slide is held by the stop forming the return stroke limiting device .

Im folgenden wird ein Ausführungsbeispiel der Erfindung unter Bezugnahme auf die Zeichnungen näher erläutert.An exemplary embodiment of the invention is explained in more detail below with reference to the drawings.

Es zeigen:

Fig. 1
einen Schnitt durch die Schlauchpumpe,
Fig. 2
in vergrößertem Maßstab die Einzelheit II aus Fig. 1,
Fig. 3
in gleicher Darstellung wie Fig. 1 den Zustand des gleichzeitigen Abquetschens des Schlauchs am vorderen und hinteren Ende des Pumpbereichs zur Verdeutlichung des abgegrenzten Fördervolumens und
Fig. 4
eine schematische Darstellung des durch den letzten Schieber in der Rückzugsposition verdrängten Volumens, das für den Rückzug des Fördermediums nicht mehr zur Verfügung steht.
Show it:
Fig. 1
a section through the peristaltic pump,
Fig. 2
on an enlarged scale the detail II from FIG. 1,
Fig. 3
in the same representation as FIG. 1, the state of simultaneous squeezing of the hose at the front and rear end of the pump area to illustrate the delimited delivery volume and
Fig. 4
a schematic representation of the volume displaced by the last slide in the retracted position, which is no longer available for the retraction of the medium.

Die Schlauchpumpe 10 ist in einer frontseitigen Gehäusewand 11 des Gehäuses eines Infusionsgerätes in einer Aussparung 12 montiert. Sie besteht aus dem starren Rahmen 13 mit dem Gegenlager 14, der Quetschvorrichtung 15 und der Andrückvorrichtung 16. Der Rahmen 13 weist ein Basisteil 17 und vier davon abstehende Stangen 18 auf. An zwei der Stangen 18 ist über ein Gelenk das Gegenlager 14 angebracht, das als aufklappbare Tür ausgebildet ist und an den beiden anderen Stangen 18 mit einem Schnellverschluß befestigt werden kann.The peristaltic pump 10 is mounted in a recess 12 in a front housing wall 11 of the housing of an infusion device. It consists of the rigid frame 13 with the counter bearing 14, the squeezing device 15 and the pressing device 16. The frame 13 has a base part 17 and four rods 18 projecting therefrom. On two of the rods 18, the counter bearing 14 is attached via a joint, which is designed as a hinged door and can be attached to the other two rods 18 with a quick release.

Ein (nicht dargestellter) Antriebsmotor, der an dem Pumpengehäuse 21 befestigt ist, treibt über ein Untersetzungsgetriebe die in dem Pumpengehäuse 21 gelagerte Nockenwelle 22. Die Nockenwelle 22 besteht aus einer Welle 23 mit Sechskantprofil und auf dieser Welle sitzenden Nockenscheiben 24, die jeweils eine Sechskantöffnung aufweisen und dadurch drehfest auf der Welle 23 sitzen. Je zwei Nockenscheiben 24 bilden eine Doppelnockenscheibe. Benachbarte Nockenscheiben sind umfangsmäßig um 30° zueinander versetzt auf der Welle 23 angeordnet und haben eine Exzentrizität von 2,5 mm, wodurch sich bei einer vollen Umdrehung der Nockenscheibe ein Hub von 5 mm ergibt.A drive motor (not shown), which is fastened to the pump housing 21, drives via a reduction gear the camshaft 22 mounted in the pump housing 21. The camshaft 22 consists of a shaft 23 with a hexagonal profile and cam disks 24 seated on this shaft, each of which has a hexagonal opening and thereby sits on the shaft 23 in a rotationally fixed manner. Two cam disks 24 each form a double cam disk. Adjacent cam disks are circumferentially offset from one another by 30 ° on the shaft 23 and have an eccentricity of 2.5 mm, which results in a stroke of 5 mm with a full rotation of the cam disk.

Jede der Nockenscheiben 24 treibt einen Schieber 25. Die Schieber sind in dem Pumpengehäuse 27 in seitlichen Nuten längsverschiebbar geführt und sie verlaufen durch Schlitze 26 der dem Gegenlager 14 zugewandten Wand des Pumpengehäuse hindurch, wobei am Ende eines jeden Schiebers 25 ein verdickter Kopf 27 angeordnet ist. Das Lagerspiel der Führungsnuten für die Schieber 25 ist so gewählt, daß sich die Köpfe benachbarter Schieber gerade berühren, daß sich jedoch Toleranzen der Schieber bzw. der Köpfe nicht addieren.Each of the cam disks 24 drives a slide 25. The slides are guided in the pump housing 27 so that they can be moved longitudinally in lateral grooves and they run through slots 26 in the wall of the pump housing facing the counter bearing 14, a thickened head 27 being arranged at the end of each slide 25 . The bearing play of the guide grooves for the slider 25 is selected so that the heads of adjacent slides just touch, but that tolerances of the slider or the heads do not add up.

Die Köpfe 27 der Schieber sind von einer Membran 28 bedeckt, die an dem Pumpengehäuse 21 befestigt ist. Das Pumpengehäuse 21 weist ferner Flansche 29 auf, mit denen es an der Gehäusewand 11 des Gerätegehäuses befestigt ist. Ein Blendrahmen 30, der bündig und abdichtend in die Öffnung 12 der Gehäusewand 11 eingesetzt ist, bildet den äußeren Abschluß des Pumpengehäuses. Dieser Blendrahmen umschließt die Membran 28.The heads 27 of the slide are covered by a membrane 28 which is attached to the pump housing 21. The pump housing 21 also has flanges 29 with which it is fastened to the housing wall 11 of the device housing. A frame 30, which is inserted flush and sealing in the opening 12 of the housing wall 11, forms the outer end of the pump housing. This frame encloses the membrane 28.

Das Pumpengehäuse 21 ist mit Gleitbuchsen längs der Stangen 18 geführt, so daß der Rahmen 13 relativ zu dem Pumpengehäuse 21 bzw. zur Quetschvorrichtung 15 in Längsrichtung der Stangen bewegt werden kann. Wenn das Gegenlager 14 sich in der Schließstellung befindet, ist es starrer Bestandteil des Rahmens 13 und kann mit diesem relativ zur Gehäusewand 11 bzw. zu der darin befestigten Quetschvorrichtung 15 horizontal verschoben werden.The pump housing 21 is guided with sliding bushes along the rods 18, so that the frame 13 relative to the pump housing 21 or the crimping device 15 in Longitudinal direction of the rods can be moved. When the counter bearing 14 is in the closed position, it is a rigid component of the frame 13 and can be moved horizontally with the latter relative to the housing wall 11 or to the crimping device 15 fastened therein.

An der Rückseite des Pumpengehäuses 21 ist eine aus mindestens einer Druckfeder bestehende Federvorrichtung 33 abgestützt. Die Federvorrichtung 33 ist in einem mit dem Pumpengehäuse 21 verbundenen Rohr 34 enthalten, das teleskopisch in ein von dem Basisteil 17 nach hinten abstehendes Rohr 35 eintaucht. Am Ende des Rohres 35 befindet sich eine Stellvorrichtung 36, die mit einem Gewinde in ein Innengewinde 37 des Rohres 35 eingreift und mit ihrem Ende gegen die Federvorrichtung 33 drückt. Durch Drehen der Stellvorrichtung 36 kann die Federkraft der Andrückvorrichtung 16 verändert werden. Die Federvorrichtung 33 greift an dem Basisteil 17 und an der Quetschvorrichtung 15 zentrisch an, d.h. entlang der Mittelachse der Quetschvorrichtung. Am Rohr 34 ist ein Gleitstück 38 vorgesehen, das ein reibungsarmes Gleiten der beiden Rohre 34 und 35 ermöglicht und das zusammen mit den Gleitbuchsen 32 dafür sorgt, daß der Rahmen 13 in Bezug auf die Quetschvorrichtung 15 verkantungsfrei linear verschiebbar geführt ist.A spring device 33 consisting of at least one compression spring is supported on the rear side of the pump housing 21. The spring device 33 is contained in a tube 34 which is connected to the pump housing 21 and which telescopically plunges into a tube 35 projecting rearward from the base part 17. At the end of the tube 35 there is an adjusting device 36, which engages with a thread in an internal thread 37 of the tube 35 and presses with its end against the spring device 33. The spring force of the pressing device 16 can be changed by rotating the adjusting device 36. The spring device 33 engages centrally on the base part 17 and on the squeezing device 15, i.e. along the central axis of the crimping device. On the tube 34, a slider 38 is provided, which enables low-friction sliding of the two tubes 34 and 35 and which, together with the sliding bushes 32, ensures that the frame 13 is guided in a linearly displaceable manner without tilting relative to the squeezing device 15.

Im Betrieb wird der Schlauch 40, der zwischen der Membran 28 und dem Gegenlager 14 vertikal verläuft, in jeder Phase der Umdrehung der Nockenwelle 22 durch mindestens einen Schieber 25 okklusiv abgequetscht. Etwaige Toleranzen von Pumpe und/oder Schlauch werden durch die Andrückvorrichtung 16 ausgeglichen, die durch die Federvorrichtung 33 bewirkt, daß der Rahmen 13 zusammen mit dem Gegenlager 14 gegen die Quetschvorrichtung 15, und somit auch gegen die Schieber 25 getrieben wird.In operation, the hose 40, which runs vertically between the membrane 28 and the counterbearing 14, is squeezed out at least in every phase of the rotation of the camshaft 22 by at least one slide 25. Any tolerances of the pump and / or hose are compensated for by the pressing device 16, which causes the frame 13 together with the thrust bearing 14 against the squeezing device by the spring device 33 15, and thus driven against the slide 25.

Auf der Auslaßseite der Schlauchpumpe ist am Pumpengehäuse 21 ein Drucktaster 39 verschiebbar angeordnet, der gegen die Membran 28 und gegen den Auslaßbereich des Pumpenschlauchs drückt. Der Drucktaster 39 ist mit einem (nicht dargestellten) Sensor gekoppelt, der die Stellung des Drucktasters 39 feststellt und dadurch den Ausgangsdruck der Pumpe ermittelt.On the outlet side of the peristaltic pump, a push button 39 is slidably arranged on the pump housing 21, which pushes against the membrane 28 and against the outlet region of the pump hose. The push button 39 is coupled to a sensor (not shown) which detects the position of the push button 39 and thereby determines the output pressure of the pump.

Beim Betrieb der Schlauchpumpe steuert die Nockenwelle 22 die Schieber 25 so, daß der Schlauch 40 fortlaufend von den Köpfen 27 zusammengedrückt und abgequetscht wird, wobei das Zusammendrücken in Förderrichtung fortschreitet, also in den Zeichnungen dieses Ausführungsbeispieles von rechts nach links. Die Schieber wirken auf den Pumpbereich des Schlauchs in einem Abschnitt, der 360° des Pumpzyklus umfaßt, d.h. der erste und der letzte Schieber sind gleichphasig gesteuert.During operation of the hose pump, the camshaft 22 controls the slide 25 so that the hose 40 is continuously compressed and squeezed by the heads 27, the compression progressing in the conveying direction, that is to say from right to left in the drawings of this exemplary embodiment. The sliders act on the pumping area of the tubing in a section that encompasses 360 ° of the pumping cycle, i.e. the first and the last slide are controlled in phase.

In Fig. 3 ist der Zustand dargestellt, daß der in Förderrichtung erste und der in Förderrichtung letzte Schieber 25 beide im äußersten vorgeschobenen Zustand sind. Die dazwischenliegenden Schieber 25 sind mehr oder weniger weit zurückgezogen, so daß das in diesem Bereich vom Schlauch 40 eingeschlossene Volumen VF das Fördervolumen darstellt, das in diesem Augenblick allseitig umschlossen ist und das in Förderrichtung vorgeschoben wird. In der Rückzugsstellung der Schieber nehmen die Köpfe 27 eine Position ein, die es dem Schlauch ermöglicht, den unverformten (runden) Zustand anzunehmen. Der Schlauch selbst hat eine eigene Rückstellfähigkeit.In Fig. 3 the state is shown that the first in the conveying direction and the last in the conveying direction slide 25 are both in the outermost advanced state. The intermediate slides 25 are withdrawn to a greater or lesser extent, so that the volume V F enclosed in this area by the hose 40 represents the delivery volume which is enclosed on all sides at this moment and which is advanced in the delivery direction. In the retracted position of the slide, the heads 27 assume a position which enables the hose to assume the undeformed (round) state. The hose itself has its own resilience.

Der in Förderrichtung letzte Schieber 25a ist generell in gleicher Weise ausgebildet wie die übrigen Schieber 25 und die ihn steuernde Nockenscheibe 24a hat die gleiche Form wie die übrigen Nockenscheiben 24. Unterschiedlich ist, daß eine Rückhubbegrenzungseinrichtung vorgesehen ist, die es dem Schieber 25a nicht erlaubt, sich soweit zurückzuziehen wie die übrigen Schieber 25. Diese Rückhubbegrenzungseinrichtung besteht aus einem Anschlag 42 der am Gehäuse 21 vorgesehen ist und gegen den der Kopf 27a des Schiebers 25a bei der Rückzugsbewegung stößt. Dieser Anschlag 42 ist so angeordnet, daß der Schieber 25a in der äußersten Rückzugsstellung, also wenn sein Kopf 27a gegen den Anschlag 42 stößt, die Hälfte des Schlauchdurchmessers (oder etwas mehr) einnimmt, so wie dies aus Fig. 4 zu ersehen ist. In dieser Darstellung ist außerdem schraffiert das Schlauchvolumen V₁ dargestellt, das bei der Rückzugsbewegung des Schiebers 25a von der Freigabe ausgeschlossen wird und das zur Verkleinerung oder Eliminierung des Rücksoges beiträgt. Würde der Schieber 25a sich so weit zurückbewegen wie die übrigen Schieber, dann würde durch den sich in diesem Bereich aufweitenden Schlauch ein Rücksog auftreten.The last slide 25a in the conveying direction is generally designed in the same way as the other slides 25 and the cam disk 24a controlling it has the same shape as the other cam disks 24. It is different that a return stroke limiting device is provided which does not allow the slide 25a, withdraw as far as the other slides 25. This return stroke limiting device consists of a stop 42 which is provided on the housing 21 and against which the head 27a of the slider 25a abuts during the retraction movement. This stop 42 is arranged so that the slider 25a in the extreme retracted position, that is, when its head 27a abuts the stop 42, takes up half the hose diameter (or a little more), as can be seen from FIG. 4. In this illustration, the tube volume V 1 is also shown hatched, which is excluded from the release during the retraction movement of the slide 25 a and which contributes to the reduction or elimination of the back suction. If the slide 25a were to move back as far as the other slides, then the hose widening in this area would cause a backward suction.

Damit die Steuerung der Nockenscheibe 24a nicht mit der durch den Anschlag 42 bewirkten Rückhubbegrenzung kollidiert, ist in dem Schieber 25a ein Spalt 43 vorgesehen, in dem sich die Nockenscheibe 24a bewegt und der eine Längsbewegung der Nockenscheibe 24a in Bezug auf den Schieber 25a zuläßt. Dadurch wird das erforderliche Bewegungsspiel der Nockenwelle in Bezug auf den Schieber 25a erreicht. Im übrigen ist der Schieber 25a in gleicher Weise ausgebildet wie die Schieber 25 und die Nockenscheibe 24a ist in gleicher Weise ausgebildet wie die Nockenscheiben 24.So that the control of the cam disk 24a does not collide with the return stroke limitation caused by the stop 42, a gap 43 is provided in the slide 25a, in which the cam disk 24a moves and which permits a longitudinal movement of the cam disk 24a with respect to the slide 25a. This achieves the required play of the camshaft in relation to the slide 25a. Otherwise, the slide 25a is designed in the same way as the slide 25 and the cam disk 24a is designed in the same way as the cam disks 24.

Claims (3)

  1. A hose pump comprising a plurality of slides (25) peristaltically compressing a hose (40), said slides being driven by a cam shaft (22) and performing strokes against said hose (40),
    characterised in
    that the last slide (25a) in the direction of discharge is controlled such that, even when in the retracted state, it compresses said hose (40) at least partly.
  2. The hose pump of claim 1, characterised in that said last slide (25a) is acted upon by a return stroke limiting means.
  3. The hose pump of claim 2, characterised in that said return stroke limiting means is a stop (42) integral with the housing, and that said last slide (25a) has a gap (43) allowing for a play with respect to the cam shaft (22).
EP91117858A 1990-11-06 1991-10-19 Hose pump Expired - Lifetime EP0484717B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4035182A DE4035182C1 (en) 1990-11-06 1990-11-06
DE4035182 1990-11-06

Publications (2)

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EP0484717A1 EP0484717A1 (en) 1992-05-13
EP0484717B1 true EP0484717B1 (en) 1994-09-07

Family

ID=6417698

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91117858A Expired - Lifetime EP0484717B1 (en) 1990-11-06 1991-10-19 Hose pump

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EP (1) EP0484717B1 (en)
AT (1) ATE111189T1 (en)
DE (2) DE4035182C1 (en)

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Publication number Priority date Publication date Assignee Title
EP4310332A1 (en) 2022-07-21 2024-01-24 B. Braun Melsungen AG Displacement unit for a medical peristaltic pump and a medical peristaltic pump

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GR1001179B (en) * 1992-03-10 1993-06-07 Micrel Kentron Efarmogon Mikro Portable linear peristaltic pump.
DE29706606U1 (en) 1997-04-12 1997-08-21 Kammerer, Rolf, 75196 Remchingen Rotary displacement pump
DE20210502U1 (en) 2002-07-06 2003-11-20 B. Braun Melsungen Ag, 34212 Melsungen Peristaltic peristaltic pump
FR2908165A1 (en) * 2006-11-08 2008-05-09 Fresenius Vial Soc Par Actions METHOD FOR CONTROLLING THE FLOW OF A PERISTALTIC PUMP AND PERISTALTIC PUMP
DE202009001865U1 (en) 2009-02-11 2010-07-22 Krauss, Gunter Pump, in particular peristaltic pump
US9163623B2 (en) 2011-12-08 2015-10-20 Carefusion 303, Inc. System and method for improved flow uniformity in a peristaltic pump mechanism
DE202018003997U1 (en) 2018-08-28 2019-12-04 Gunter Krauss Pump, especially peristaltic pump
US20230349374A1 (en) * 2020-05-04 2023-11-02 The Board of Regents for the Oklahoma Agricultural and Mechanical Colleges Peristaltic compressor

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US4322201A (en) * 1979-03-09 1982-03-30 Avi, Inc. IV Pump with back pressure control
JPS56113084A (en) * 1980-02-12 1981-09-05 Terumo Corp Pulsation preventing method and device for peristaltic finger pump
JPS61228872A (en) * 1985-04-01 1986-10-13 シャープ株式会社 Liquid drug injection apparatus
US4781548A (en) * 1987-04-10 1988-11-01 Alderson Richard K Infusion pump system and conduit therefor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4310332A1 (en) 2022-07-21 2024-01-24 B. Braun Melsungen AG Displacement unit for a medical peristaltic pump and a medical peristaltic pump
DE102022118250A1 (en) 2022-07-21 2024-02-01 B. Braun Melsungen Aktiengesellschaft Displacement unit for a medical peristaltic pump and medical peristaltic pump

Also Published As

Publication number Publication date
DE4035182C1 (en) 1992-01-02
DE59102830D1 (en) 1994-10-13
EP0484717A1 (en) 1992-05-13
ATE111189T1 (en) 1994-09-15

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