DE102017116398A1 - Volumetric pump - Google Patents

Abstract

The present invention relates to a volumetric pump (1) for conveying media through a flexible hose (2) with a housing (4) which can be closed by means of a door (3), a displacement device (5) for introducing a pressure force onto the flexible hose (2 ), an abutment portion (6) on which the flexible hose (2) is arranged and supported against the force introduced by the displacement means (5) and an adjustable biasing means (7), by means of which the displacement means (5) and / or the anvil (6) are mounted with an adjustable compliance or biased against each other to allow an adjustment of the hose (2) introduced or can be introduced pressure force. The displacement means (5), the abutment portion (6) and the biasing means (7) are arranged therein in the closed state of the housing (4) and the biasing means (7) is in the closed state of the housing (4) adjustable from the outside, without requiring the housing (4) must be opened.

Description

Technical area

The present invention relates to a volumetric pump for conveying media through a flexible hose with a closable by a door or flap housing, a displacement means for introducing a pressing force on the flexible hose, an abutment portion on which the flexible hose is arranged and on which the flexible hose pressed by the displacement device and an adjustable pretensioning device, by means of which the displacement device (eg slide peristaltic or pump rotor) and / or the counter bearing are mounted with an adjustable resilience or biased against each other, for adjusting the pressure applied to the hose or can be introduced enable.

State of the art

Various infusion hose pumps (squeeze pumps) are known from the prior art. These are used, for example, to promote an active substance with a certain delivery rate from a drug reservoir via an infusion tube to or into a patient. Infusion tube pumps are usually designed as volumetric pumps, which displace a volume in the infusion tube from the outside. This has the advantage that the displacement device (slide peristalsis / pump rotor) remains unaffected by the media carried in the hose or does not come into contact with the media. In such pumps, the pressure force of the peristaltic provides a significant contribution to the delivery accuracy It is therefore necessary to precisely adjust this pressure force, for example, to adjust them to the different elasticity of different tubes (disposable). There is a long felt need among those in the art to further improve the delivery accuracy and pressure stability of infusion tube pumps, for example, to deliver medicines at even more precise dosages.

Furthermore, there is the risk of uncontrolled failure in the adjusting device for the pressing force, for example. By the breakage of a spring in known solutions. In such a case, the peristaltic slides may lift off from their corresponding counter bearing, resulting in an uncontrolled amount of drug entering or exiting the patient.

Brief description of the invention

It is therefore an object of the present invention to provide means by which the delivery accuracy in a volumetric pump can be improved.

The above object is achieved by a device having the features of claim 1. Advantageous developments are the subject of the dependent claims.

• ein mittels einer Tür/Klappe/Deckel verschließbares Gehäuse,
• eine Verdrängungseinrichtung, insbesondere eine Schieberperistaltik oder ein Pumpenrotor, zum Auf-/Einbringen einer (längs des Schlauchs wandernden) Andruckkraft auf den flexiblen Schlauch,
• einen Gegenlagerabschnitt (Widerlager), an welchem der flexible Schlauch angeordnet und in Folge der durch die Verdrängungseinrichtung auf-/eingebrachten Andruckkraft abgestützt wird und
• eine justierbaren Vorspanneinrichtung, mittels welcher die Verdrängungseinrichtung und/oder der Gegenlagerabschnitt mit einer einstellbaren Nachgiebigkeit gelagert oder gegeneinander vorgespannt sind, wobei ein Justieren der (durch die Verdrängungseinrichtung) auf den Schlauch auf-/eingebrachten oder auf-/einbringbaren Andruckkraft ermöglicht ist.

Basically, a volumetric pump according to the invention for conveying media through a flexible hose has the following features / components:

• a closable by means of a door / flap / lid housing,
• a displacement device, in particular a slide peristaltic or a pump rotor, for mounting / bringing in a pressure force (traveling along the hose) on the flexible hose,
• an abutment portion (abutment) on which the flexible hose is arranged and supported as a result of the up / introduced by the displacement means pressure force and
• an adjustable biasing means, by means of which the displacement means and / or the abutment portion are mounted with an adjustable compliance or biased against each other, with an adjustment of the (by the displacement means) on the hose up / introduced or on / engageable Andruckkraft is possible.

According to the invention, the displacement means, the abutment portion and the biasing means are arranged within the same in the closed state of the housing and the biasing means is adjustable in the closed state of the housing from the outside, without requiring the housing must be opened. In other words, the volumetric pump according to the invention is designed to promote a certain amount of fluid / active agent / infusion solution by means of a displacement device (slide peristaltic / pump rotor) by the compression of a defined tube volume with a defined, set by a biasing device / introduced pressure force. The individual components of the displacement device (the pump mechanism) are designed in such a constructive manner and matched to the housing, that the pressure force of the displacement device generated by the biasing device from the outside and without a Disassembly or opening of the housing can be adjusted / adjusted.

In known solutions, it is quite possible to adjust the pressing force of the displacement device (peristaltic), but this is an opening or dismantling of the pump (the pump housing) required. Due to the reassembly of the pump and the resulting tolerances, this leads to inaccuracies or deviations and the achievable delivery accuracy is consequently limited. The arrangement according to the invention described above therefore not only offers ergonomic advantages for the user but also enables improved conveying accuracy, since the pressure force of the pretensioning device can be adjusted when the housing is closed and the dimensional deviations / tolerances during reassembly of the pump can be compensated.

According to a preferred aspect of the invention, the biasing means may be adapted to be adjusted purely mechanically. Preferably, the biasing means may comprise an adjusting spring, that is, a spring element whose biasing force can be adjusted by moving an actuator.

According to a preferred embodiment, the displacing means may comprise a number of peristaltic slides, e.g. in a fixed slide housing (in a sliding direction) are mounted linearly displaceable and driven by an eccentric shaft with a number of (angular offset) eccentric cam. In other words, the displacement device can be designed as a slide peristaltic. In such a slide peristalsis, the number of slides is preferably driven by the eccentric shaft in such a way that, displaced in succession, in a wave movement, they push a defined volume in the flexible hose in a conveying direction. The slider housing can either be a separate inner housing, which is arranged inside the (pump) housing or also be an integral section of the (pump) housing, on which the peristaltic slides are mounted linearly displaceable. Preferably, the peristaltic slides thus mounted have a single degree of freedom in the sliding direction. The eccentric shaft can preferably be mounted rotatably and can be driven to rotate, preferably by a motor.

In principle, however, it is also possible to equip the (squeezing) pump with a pump rotor, at the periphery of a number of angularly spaced pressure rollers is mounted, wherein the flexible hose is arcuately guided around the pump rotor and thereby against the also arcuate to the flexible hose (Around the pump rotor) formed abutment portion quasi applies as a hose guide.

In a preferred aspect, the pusher housing / rotor housing may be fixed to the (pump) housing to provide precise guidance of the peristaltic pusher / pressure rollers. In the prior art, the entire slide housing / rotor housing is biased towards the abutment portion for introducing the adjustable pressure force often. However, the resulting mobility of the storage of peristaltic shifter / pressure rollers is reflected in a less accurate promotion.

According to a preferred embodiment, the eccentric shaft or the pump rotor shaft relative to the slide housing may be resiliently mounted. Preferably, the biasing means bias the eccentric shaft / pump rotor shaft directly or indirectly toward the abutment portion, so as to generate the pressing force.

According to a further preferred aspect of the invention, the eccentric shaft (the slider peristaltic) can be pivotably mounted on the pendulum arm via a pendulum arm on the slide housing (fixed relative to the housing). The eccentric shaft itself is rotatably mounted on the pendulum arm in such an embodiment.

According to a preferred embodiment, the biasing device in the transverse direction to the sliding direction, in particular in the direction perpendicular to the sliding direction and perpendicular to the orientation of the tube inserted in the housing, act. This has the background that the housing of volumetric pumps in the sliding direction and in the tube insertion direction due to the space required in these directions usually larger dimensions / edge lengths than perpendicular to these two directions (usually the vertical direction). By aligning the biasing device perpendicular to the sliding direction and the tube loading direction so the distance of the biasing device can be reduced to the housing outer surface to facilitate an adjustability of the same from the outside. Particularly preferably, the eccentric shaft can be mounted on the pivotable relative to the slide housing pendulum and the biasing device can, for example. Via a cantilever arm of the pendulum, in the transverse direction to the sliding torque on the pendulum apply, which the torque generated by the pressing force of the slider peristalsis on the Pendulum counteracts.

• eine Einstellschraube;
• ein Federelement, welches axialverschiebbar und im Wesentlichen konzentrisch an der Einstellschraube angeordnet ist; und
• einen Federhalter, welcher axialverschiebbar und im Wesentlichen konzentrisch an der Einstellschraube angeordnet und dazu ausgebildet ist, ein axiales Ende des Federelements in einer bestimmten axialen Position relativ zur Einstellschraube zu halten,
• aufweisen.

According to a preferred embodiment, the biasing device

• an adjusting screw;
• a spring element, which is arranged axially displaceable and substantially concentric with the adjusting screw; and
• a spring holder which is axially displaceable and substantially concentric with the adjusting screw and adapted to hold an axial end of the spring element in a specific axial position relative to the adjusting screw,
• exhibit.

According to a further preferred aspect of the invention, the spring holder, in particular via a self-locking thread pairing, be so connected with adjusting screw that it moves forcibly guided due to a rotational movement of the Einstellschraub in the axial direction. In this way, the biasing device can be designed such that the pressing force can be adjusted by a simple rotational movement. A self-locking design of the thread pairing can prevent unwanted adjustment / procedure of the spring holder, for example. As a result of the biasing force applied.

According to a preferred embodiment, the spring holder on the housing or the slider housing, in particular by a positive connection, linearly displaceable and rotationally secured to be stored.

According to a preferred embodiment, the adjusting screw can be rotatably mounted on the housing and / or the slider housing and / or the pendulum arm. More preferably, the adjusting screw having a circumferential detent, by means of which the adjusting screw in a number of predetermined angular increments relative to the housing can be latched.

According to a further preferred aspect of the invention, the spring element may be formed as a compression spring. More preferably, the spring element may be formed as an axial wave spring. In this way, space can be saved in the axial direction of the spring element. Even more preferably, the spring element / the wave spring may be formed / shaped in such a way that it can not rotate after a break and retains the stored force. If the spring of the counterpressure bearing breaks, an uncontrolled flow occurs in both directions immediately (depending on the pressure level). The use of the wave spring is safe at this point, as in a fraction of a turn, the spring force is almost maintained.

According to a preferred embodiment, the volumetric pump may comprise a through-bore or recess in the housing and / or the slider housing which is formed corresponding to, in particular concentric with, the biasing means to provide accessibility thereto. It is advantageous if the through-bore / recess is sealed by a sealing device to prevent the entry of dirt into the housing interior.

The invention will be explained below with reference to preferred embodiments with reference to the accompanying figures. The figures are merely schematic in nature and are for the sole purpose of understanding the invention. The same elements are provided with the same reference numerals.

• 1 eine schematische Schnittansicht durch eine erfindungsgemäße volumetrische Pumpe gemäß einer bevorzugten Ausführungsform der Erfindung;
• 2 eine Explosionsansicht einer Verdrängungseinrichtung der volumetrischen Pumpe gemäß der bevorzugten Ausführungsform;
• 3 eine perspektivische Rückansicht der Verdrängungseinrichtung der volumetrischen Pumpe gemäß der bevorzugten Ausführungsform;
• 4 eine Detailansicht einer justierbaren Vorspanneinrichtung gemäß einer bevorzugten Ausführungsform;
• 5 ein Schema des Kräftegleichgewichts in der Verdrängungseinrichtung; und
• 6 eine schematische Ansicht einer weiteren bevorzugten Ausführungsform einer erfindungsgemäßen volumetrischen Pumpe der radialen Bauart.

Show it:

• 1 a schematic sectional view through a volumetric pump according to the invention according to a preferred embodiment of the invention;
• 2 an exploded view of a displacement device of the volumetric pump according to the preferred embodiment;
• 3 a rear perspective view of the displacement device of the volumetric pump according to the preferred embodiment;
• 4 a detailed view of an adjustable biasing device according to a preferred embodiment;
• 5 a diagram of the balance of power in the displacement device; and
• 6 a schematic view of another preferred embodiment of a volumetric pump according to the invention of the radial design.

In medical technology, the use of volumetric pumps is known. In such pumps, the pressure force of peristaltic makes a significant contribution to the delivery accuracy. It is therefore necessary to adjust the pressure force of the peristalsis as precisely as possible. In known pumps, such an adjustment of the pressure force of the peristaltic is possible only in a disassembled or opened state of the pump housing. Due to the assembly-related position tolerances of the individual components arising during reassembly of the pump, the achievable accuracy of adjustment of such pumps is limited. Object of the present invention is therefore to provide a pump mechanism with higher adjustment accuracy. This is especially true ensures that the individual components of the pump are designed in such a constructive manner that the adjustment of the pressure force of the peristaltic in the closed state of the pump housing (without disassembly of the pump) can be done.

In 1 is a volumetric pump 1 for conveying media through a flexible hose 2 represented according to a preferred embodiment of the invention. More specifically, it is an infusion tube pump, which can supply or supply a means of action from an agent reservoir (not shown) at a predetermined delivery rate via an infusion line to a patient. This is indicated by the volumetric pump 1 basically a means of a door 3 lockable housing 4 on. In operation, the flexible hose 2 between door 3 and housing 4 arranged. The hose 2 is in this arrangement between one in the housing 4 arranged displacement device 5 and one through the door 3 trained counter bearing section 6 provided, wherein the abutment portion 6 an abutment to one by the displacement device 5 generated pressure force forms.

The in the 2 and 3 shown displacement device 5 the volumetric pump 1 is designed as a slider peristalsis mechanics. As such, it has a number of (peristaltic) sliders 8th (here twelve), which in a slide housing 9 are mounted linearly movable. The sliders 8th be via an eccentric shaft 10 driven, which is about one of the number of slides 8th corresponding number of eccentric cams 10.1 each corresponding to a slider 8th are arranged. The eccentric cams 10.1 the illustrated eccentric shaft 10 are each about 30 ° relative to the or each adjacent eccentric cam 10.1 offset, so that, at one by a motor 11 driven rotation of the eccentric shaft 10 that, by the eccentric cam 10.1 in their linear motion positively driven slide 8th , Promote a volume in a conveying direction in a substantially sinusoidal displacement movement.

The slide housing 9 is fixed to the pump housing 4 arranged to guide the slider as accurately as possible 8th to enable. In the example shown, the slider housing 9 formed as a separate housing (inner body), which advantageously on the pump housing 4 (Outer body) is positively and / or non-positively attached. In the example shown, the attachment of the valve body 9 on the housing 4 by means of pressed-in pin. However, all conventional fastening methods are considered, for example by means of other fastening means such as screws, a positive connection or a press or welded connection. The slide housing 9 Can also be used as a one-piece section of the case 4 be educated.

Both slide housing 9 as well as the counter bearing section 6 So are in the illustrated volumetric pump with respect to the pump housing 4 established. The adjustable pressure force of the peristaltic slides 8th opposite the abutment section 6 is therefore on the storage of the eccentric shaft 10 realized. For this purpose, the eccentric shaft is relatively movable to the remaining components of the displacement device 5 stored. In the example shown, the eccentric shaft 10 over one, on a slider housing hinge 9.2 mounted, pendulum 9.1 relative to the valve body 9 pivotable. To generate the adjustable pressure, the pendulum arm 9.1 by means of the adjustable pretensioning device 7 biased so that the pendulum 9.1 rotatably mounted eccentric shaft 10 in the direction of the abutment portion 6 is urged (cf. 1 ). Accordingly experienced by the eccentric shaft 10 positively driven slide 8th a force application, corresponding to the biasing force of the biasing device 7 ,

To adjust the adjustability of the biasing device 7 To ensure force introduced into the peristaltic mechanism is the pretensioning device 7 formed in the illustrated preferred embodiment as (in this case, three-part) spring adjustment. The spring adjustment is in the illustrated displacement device 5 formed as an adjustable pressure-loaded spring, which between a boom 9.4 of the valve body 9 and a cantilever arm 9.5 of the pendulum arm 9.1 is tensioned to bias the eccentric shaft in the direction of the abutment portion.

How best that 2 and 3 can be seen, the biasing device is here substantially transverse to the sliding direction of the peristaltic valve 8th arranged. The pretensioner 7 thus generates a torque about the axis of rotation of the slider housing hinge 9.2 to which the pendulum arm 9.1 is pivotable, which by the pressure force of the peristaltic slide 8th generated torque is opposite. The vertical alignment of the biasing direction and the sliding direction of the peristaltic slides 8th relative to each other has the advantage that the distance to the pump housing 4 is shorter in the transverse direction to the sliding direction than in the sliding direction or in tube loading direction. This is because volumetric pump housings are generally cuboid and have the shortest edge length in a direction transverse to the sliding direction and to the tube loading direction (usually the vertical direction). In other words, the accessibility of the adjustable pretensioning device can be achieved by such a structural design 7 from outside the case 4 improve because a smaller distance must be bridged.

To adjust the adjustability of the pretensioner 7 in the assembled state of the housing 4 to provide, is in the pump shown a through hole 12 through the housing 4 and by the cantilever arm 9.4 of the valve body 9 provided, to which the biasing device 7 is arranged concentrically and through which the biasing means 7 is accessible. As 4 can be seen, the access to the spring adjustment in the example shown by a sealing device 13 (which here has a screw plug and a sealing ring) sealed to prevent ingress of dirt particles in the pump gearbox. Adjacent to the in 4 illustrated access to the adjustable biasing device 7 are also on the outside of the pump housing 4 marks 14 provided which indicate to the user the corresponding direction of rotation with increasing or decreasing the pressure force of the peristaltic.

In the illustrated preferred embodiment, the biasing device formed here as a spring adjustment 7 three-piece from an adjusting screw 7.1 , a spring element (wave spring) 7.2 and a penholder 7.3 (Retaining ring) constructed. The adjusting screw is as in 3 can be seen, rotatable on the boom 9.4 of the valve body 9 and the boom arm 9.5 of the pendulum arm 9.1 stored. The penholder 7.2 acts via an internal thread with an external thread of the adjusting screw 7.1 together and thus proceeds with a rotational movement of the adjusting screw 7.1 relative to this in the axial direction. For this purpose, the pen acts 7.2 additionally such a positive fit with the slide housing 9 together that this against twisting or turning with the adjusting screw 7.1 secured and yet mounted axially movable relative to the slide housing. This is achieved in the example shown in that the spring holder 7.3 forms an integral fork portion, which is a rib 9.3 of the valve body 9 positively receives. stop surfaces 9.6 on the slide housing 9 limit the possible compression of the spring element 7.2 ,

The spring element 7.2 is advantageously arranged such that it with their axial ends a shock with the spring holder 7.3 and the boom arm 9.4 of the pendulum arm 9.1 forms. In this way, the spring element 7.2 the on the pendulum arm 9.1 mounted eccentric shaft 10 in the direction of the abutment portion 6 Pretension. Turning the adjusting screw 7.1 triggers an axial procedure of the spring holder 7.3 as a result, the spring element 7.2 is compressed or relaxed. An adjustment of the pendulum arm 9.1 introduced biasing force is thus by simply turning the adjusting screw 7.1 allows, which through the through hole / recess 12 is accessible.

The spring element 7.2 is formed in the illustrated preferred embodiment as a wave spring. This has the advantage that wave springs require comparatively little space in the axial direction in order to apply the same force as many other types of springs. In addition, the wave spring - in contrast to conventional (spiral) compression springs - be designed such that at a fraction at a position of the spring element 7.2 , the two resulting from the fracture fragments can not rotate relative to each other. This is particularly advantageous for the present medical application, as in this way, even with a failure of the spring element 7.2 the prestressing force stored in the same can be securely maintained. If this were not the case, it could be at a failure of the spring element 7.2 to fluctuations in the delivery rate and thus to an uncontrolled drug delivery come.

The internal thread of the spring holder 7.3 and the external thread of the adjusting screw 7.1 are in the example shown as a self-locking thread (eg., As a trapezoidal thread) formed to prevent the axial position of the spring holder 7.3 changed as a result of the biasing force or to ensure that the contact pressure set by the user is maintained.

At the adjusting screw 7.2 is a circumferential crown-shaped detent 15 provided, which with a corresponding Rastungsabschnitt 16 (For example, a triangular profile-shaped locking lug) of the valve body 9 cooperates to prevent accidental adjustment of the adjustment screw 7.1 , (in addition to the self-locking thread) to prevent. The detent 15 . 16 gives the user also a better haptic and acoustic feedback when going through the angular steps, if this the pressure force by means of the biasing device 7 adjusted.

5 shows a schematic representation of a balance of forces within the illustrated displacement device 5 , The eccentric shaft 10 pushes the slider 8th towards the flexible hose 2 to effect a repression. This is from the fixed abutment section 6 held by a restoring force F _R arises, which on the eccentric shaft 10 and thus on the boom 9.1 (on which the eccentric shaft 10 rotatably mounted). As a result, torque is generated on the slider housing hinge 9.2 on which the pendulum arm 9.1 is pivotally mounted. A perpendicular to the main body of the pendulum arm 9.1 oriented boom 9.5 learns a preload force F _V by the spring element 7.2 which perpendicular to the restoring force F _R is aligned and by the restoring force F _R counteracts generated torque.

In 6 is an alternative embodiment of a volumetric pump according to the invention 1 shown, which is designed in this case not as Schieberperistaltikpumpe but as a radial peristaltic pump (peristaltic pump). According to the embodiment described above, also the radial peristaltic pump 1 one by means of a door 3 lockable housing 4 on. In the case 4 an insert recess is formed with a substantially arcuate outer edge, which the abutment portion 6 represents. The displacement device 5 is in the in 6 illustrated embodiment as a pump rotor 5 formed, which rotatable in the housing 4 is stored and a number (here three) of pressure rollers or sliding shoes 5.1 having. The pump rotor 5 is disposed within the recess so that it in conjunction with the part-circular edge of the same (ie the abutment portion 6 ) forms an arcuate gap into which the flexible hose 2 can be inserted or inserted. With a rotation of the pump rotor 5 the tube experiences 2 through the pressure rollers / sliding shoes 5.1 one in the axial direction of the hose (in the circumferential direction of the pump rotor 5 ) migratory pressure force which the hose 2 in cooperation with the anvil section 6 squeezes to a defined extent and pushes in this way a volume in a conveying direction / promotes. Also with the radial volumetric pump 1 , the pressure force is adjustable. In the example shown, the pump 1 for this purpose two separate adjusting springs 7 on, with which the abutment section 6 and the pump rotor 5 each biased against each other (towards each other). According to the invention are both Justierfedern 7 such in the housing 4 (For example, in a through hole in the same) arranged that they are adjustable from the outside, without the door 3 opened or the case 4 must be dismantled. The abutment section 6 In the example shown, it is opposite the rest of the housing 4 mounted relatively movable to bias it against the pump rotor 5 to enable. Preferably, the biasing force of the biasing means 7 which the biasing force on the pump rotor 5 applies and thus this in the direction of the abutment portion 6 urges, into the rotor axis 5.2 initiated. Of course, it is sufficient to implement the invention, a single biasing device 7 provide, which either the pump rotor 5 or the counter bearing section 6 towards the other component 5 . 6 biases.

In summary, the volumetric pump according to the invention 1 Thus, by various constructive measures (such as, the mutually perpendicular alignment of the sliding and the biasing direction or the use of an axial on pressure loaded wave spring) adapted to the pressure force of the displacement device (peristaltic mechanism) from the outside and without disassembly of the housing 4 can be adjusted. For the user, this means that the pressure force could even be adjusted without the hose 2 (Disposable) would have to be taken out.

LIST OF REFERENCE NUMBERS

1

volumetric pump;

2

flexible hose;

3

Door / pump flap;

4

Casing;

5

Displacement device;

5.1

Pressure rollers / guide shoes;

5.2

Rotor axis;

6

Thrust bearing portion;

7

adjustable pretensioner;

7.1

adjusting screw;

7.2

Spring element;

7.3

Pen holder;

8th

slide;

9

Slide housing;

9.1

pendulum;

9.2

Slide housing hinge;

9.3

Rib;

9.4

Cantilever arm of the valve body;

9.5

Cantilever arm of pendulum arm;

9.6

stop surfaces

10

eccentric shaft;

10.1

eccentric cam;

11

Engine;

12

Through-hole;

13

Seal means;

14

Mark;

15

detent;

16

Rastungsabschnitt.

Claims (10)

Volumetric pump (1), in particular infusion pump, for conveying media through a flexible hose (2) with - a housing (4) which can be closed by means of a door or flap (3); - A displacement device (5), in particular a slide peristalsis, for applying / introducing a pressing force on the flexible hose (2); - An abutment portion (6) on which the flexible hose (2) is arranged and on which the flexible hose (2) against the by the displacement means (5) introduced pressure force is supported; and - an adjustable biasing means (7) by means of which the displacement means (5) and / or the abutment portion (6) are biased at least partially biased or biased against each other with an adjustable biasing force to an adjustment of the hose (2) introduced or introduced To allow pressure force, characterized in that the displacement means (5), the abutment portion (6) and the biasing means (7) are arranged in the closed state of the housing (4) within the same such that the biasing means (7) in the closed state of the housing (4) is adjustable from the outside without for this purpose the housing (4) must be opened. Volumetric pump (1) according to Claim 1 , characterized in that the biasing means (7) as a purely mechanical spring adjustment (7.1, 7.2, 7.3) is formed, which is accessible from outside the housing (4). Volumetric pump (1) according to Claim 1 or 2 , characterized in that the displacement means (5) comprises a number of peristaltic slides (8) which are mounted linearly displaceable in a fixed slide housing (9) in a sliding direction and driven by an eccentric shaft (10), which in particular on a pendulum (9.1 ) and by means of the biasing means (7) relative to the slide housing (9) is resiliently mounted. Volumetric pump (1) according to one of Claims 1 to 3 , characterized in that the biasing means (7) introduces the biasing force via the eccentric shaft (10) into the displacing means (5). Volumetric pump (1) according to Claim 3 or 4 , characterized in that the biasing means (7) is formed such that the introduced by this biasing force is aligned transversely to the sliding direction of the peristaltic slide (8). Volumetric pump (1) according to one of Claims 1 to 5 , characterized in that the biasing means (7) comprises an adjusting screw (7.1); a spring element (7.2), in particular a wave spring, which is arranged axially displaceable and substantially concentric with the adjusting screw (7.1); and a spring holder (7.3), which is axially displaceable and substantially concentric with the adjusting screw (7.1) and is adapted to hold an axial end of the spring element (7.2) in a certain axial position relative to the adjusting screw (7.1). Volumetric pump (1) according to Claim 6 , characterized in that the spring holder (7.3), in particular via a self-locking thread pairing, so with adjusting screw (7.1) is connected, that it moves forcibly guided in the axial direction due to a rotational movement of the adjusting screw (7.1). Volumetric pump (1) according to Claim 6 or 7 , characterized in that the adjusting screw (7.1) is rotatably mounted on the housing (4) and / or the slide housing (9) and a detent (15), by means of which the adjusting screw (7.1) in a number of predetermined angular increments relative to the housing (4) and / or the slide housing (9) can be latched. Volumetric pump (1) according to one of Claims 6 to 8th , characterized in that the spring element (7.1) is designed as a wave spring and in its geometry such that it can not rotate after a break. Volumetric pump (1) according to one of the preceding claims, characterized by a through hole (12) or recess in the housing (4) and / or the slider housing (4) which is formed corresponding to, in particular concentric with, the biasing means (7) to provide accessibility to the same.

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