US20130045121A1

US20130045121A1 - Peristaltic Pump

Info

Publication number: US20130045121A1
Application number: US13/522,895
Authority: US
Inventors: Sergej Rodau; Martin Baecke; Uwe Schwerdtfeger
Original assignee: Ulrich GmbH and Co KG
Current assignee: Ulrich GmbH and Co KG
Priority date: 2010-03-01
Filing date: 2011-02-08
Publication date: 2013-02-21
Also published as: RU2012140061A; DE102010000594B4; BR112012022097B1; EP2542781B1; TW201144605A; DE102010000594A1; CN102782325A; RU2534648C2; KR20130025377A; WO2011107326A1; EP2542781A1; BR112012022097A2; ES2459308T3

Abstract

The invention relates to a peristaltic pump (1) for conveying a medium conducted in a hose, having a plurality of squeezing elements (3) which press the hose, so as to squeeze the hose, against a counter bearing (4) and thereby convey the medium in the hose onward in the conveying direction. To permit a simpler and faster insertion of a hose in a peristaltic pump of said type, it is provided according to the invention that the peristaltic pump has a threading device for inserting the hose between the squeezing elements (3) and the counter bearing (4).

Description

The invention pertains to a peristaltic pump according to the preamble of Claim 1.
Such peristaltic pumps are used in particular in medical engineering, for example, as an infusion pump or in injection and dialysis devices. Peristaltic pumps of the initially described type for use in contrast agent injection devices are described in EP 2 011 541 A2 and include a previously used injection device by the applicant that is available on the market under the designation “ulrich missouri/mississippi.” This known contrast agent injection device comprises a peristaltic pump of the initially described type with three squeezing elements that are realized in the form of squeezing rollers and serve for pressing a hose that is inserted into the peristaltic pump and carries the contrast agent or an NaCl rinsing solution against a pivotable counter bearing in order to squeeze the hose and thusly convey the medium in the hose onward in the conveying direction. In this case, the squeezing rollers are arranged on a rotatively driven carrier disk in a freely rotatable fashion. During the operation of the pump, the carrier disk rotates in the clockwise direction and the squeezing rollers arranged on the carrier disk rotate in the counterclockwise direction. The rotary motion of the carrier disk and the squeezing rollers is realized with the aid of a driving motor and a gear mechanism, to which the carrier disk and the squeezing rollers are coupled. The counter bearing is realized in two parts and consists of two counter bearing segments that have the shape of a segment of a circle and are respectively arranged on a pivoted flap. The two pivoted flaps can be pivoted relative to one another about a common pivoting axis. In order to insert a hose into the peristaltic pump, the two flaps are initially pivoted apart such that the hose can be manually inserted between the outer circumference of the squeezing rollers and the counter bearing segments that are pivoted away from the squeezing rollers together with the flaps. Before the hose is inserted, the pump is manually turned into a suitable position for the insertion of the hose such that the hose can be threaded between the outer circumference of the squeezing rollers and the outwardly pivoted counter bearing segments. After the hose has been inserted, the two flaps are once again pivoted together such that the two counter bearing segments are brought in contact with and press the hose against the outer circumference of the squeezing rollers. After the two pivoted flaps with the counter bearing segments arranged thereon have been pivoted inward, the two flaps are locked and the peristaltic pump can be set in rotation in order to convey the medium carried in the hose.
However, the insertion of the hose into the peristaltic proves complicated and time-consuming. Pivoting the two pivoted flaps apart and together and turning the pump into a suitable position for the insertion of the hose are particularly time-consuming procedures. In addition, the insertion of the hose requires a correspondingly skilled operator.
Based on these circumstances, the invention aims to additionally develop a peristaltic pump of the initially described type in such a way that a simpler and faster insertion of a hose into the peristaltic pump can be achieved.
This objective is attained with a peristaltic pump with the characteristics of Claim 1. Preferred embodiments of the peristaltic pump are disclosed in the dependent claims.
The inventive peristaltic pump features a threading device for threading the hose between the squeezing elements and the counter bearing. The hose is automatically inserted into the peristaltic pump with the threading device. The operator merely needs to place the hose that is bent in a loop-shaped fashion into the threading device and start the pump. The threading device is activated together with the peristaltic pump and automatically inserts the hose into the peristaltic pump between the squeezing elements and the counter bearing, wherein the hose is squeezed between the squeezing elements and the counter bearing and pulled further into the peristaltic pump in the conveying direction thereof due to the pump motion until the hose is completely pulled into the peristaltic pump.
The threading device preferably comprises a screw spindle that is arranged on a shaft. In this case, the shaft is rotatably supported in a housing part of the peristaltic pump and set in rotation by a spindle drive. The spindle drive is advantageously coupled to the driving motor of the peristaltic pump such that the spindle drive is set in motion together with the driving motor as soon as the peristaltic pump is switched on. When the peristaltic pump is switched on, the threading device initially guides a hose placed into the top flight of the screw spindle downward in the direction of the plane in which the squeezing rollers and the counter bearing are arranged, and then automatically threads the hose into the peristaltic pump between the squeezing elements and the counter bearing. Due to the motion of the peristaltic pump realized with the aid of the driving motor, the hose ultimately is completely pulled into the peristaltic pump along the entire length or the entire circumference of the counter bearing.
A fixing device for fixing the hose is advantageously provided in order to insert the hose into the threading device, wherein the fixing device preferably makes it possible to fix the hose at a first location on the intake side of the peristaltic pump and at least one second location on the output side of the peristaltic pump. After the insertion of the hose into the fixing device, the hose fixed at the two fixing points extends between these two fixing points in a loop-shaped fashion.
In a preferred exemplary embodiment, the peristaltic pump is realized in the form of a rotary peristaltic pump, wherein the squeezing elements consist of squeezing rollers that are rotatably supported on a carrier disk. During the operation of the pump, the carrier disk and the squeezing rollers are set in rotation by a driving motor. In this case, the motion of the driving motor is advantageously transmitted to the carrier disk and the squeezing rollers via an epicyclic gear such that the carrier disk, as well as the squeezing rollers rotatably supported therein, can also be set in rotation without an inserted hose. When the peristaltic pump is started, the carrier disk therefore is also set in rotation if the hose is not yet inserted. The threading device simultaneously threads the hose placed therein into the peristaltic pump by guiding the hose in the direction of a squeezing element (squeezing roller) situated adjacent to the threading device and a counter bearing situated opposite the squeezing element.
In order to promote the automatic threading of the hose into the peristaltic pump by means of the threading device, at least one guide roller is provided in addition to the squeezing rollers. It is preferred to provide several guide rollers that respectively are rotatably arranged on the carrier disk between adjacent squeezing rollers. On their outer circumference, the guide rollers feature a circumferential groove 34, into which the hose can engage. When the hose is guided downward in the direction of the carrier disk by the threading device, it engages into the groove on the outer circumference of the guide roller that currently lies adjacent to the threading device. The rotation of the carrier disk causes the guide roller arranged thereon to continue moving in the conveying direction of the pump such that it not only pulls the hose downward in the direction of the carrier disk, but also presses the hose radially outward against the counter bearing due to the positive fit. As the carrier disk continues to rotate, the guide roller pulls the hose further into the peristaltic pump along the inner circumference of the counter bearing with the shape of a segment of a circle due to the static friction on the hose surface and the frictional engagement in the groove on the outer circumference of the guide roller, namely until the carrier disk with the guide roller arranged thereon has carried out (nearly) one complete revolution and the hose is completely pulled into the peristaltic pump due to the further rotation of the carrier disk. The rotation of the carrier disk ultimately causes the hose to be squeezed against the counter bearing by the squeezing roller that follows the guide roller on the carrier disk such that it is clamped between the squeezing roller and the counter bearing.
In order to ensure that the carrier disk, as well as the squeezing rollers rotatably supported therein, can be set in rotation if the hose is not yet inserted, a gear mechanism with a sun wheel that is connected to a driveshaft of the drive in a rotationally rigid fashion and a first planetary wheel that is connected to the respective squeezing roller in a rotationally rigid fashion and an epicyclic gear are provided, wherein said epicyclic gear comprises the sun wheel and at least one planetary wheel for each squeezing roller that is coupled to the inner circumference of the pump housing that acts as a crown wheel. In this way, the torque transmitted from the driveshaft to the sun wheel is transmitted to the carrier disk by the sun wheel via the inner circumference of the stationary pump housing that acts as a crown wheel such that the carrier disk is also set in rotation without an inserted hose during the operation of the pump.

Other advantages and characteristics of the invention result from the exemplary embodiment described below with reference to the attached drawings. In these drawings:

FIG. 1 shows a top view of an injection device, in which an inventive peristaltic pump is used;

FIG. 2 shows a perspective representation of an inventive peristaltic pump;

FIG. 3 shows an exploded view of the peristaltic pump according to FIG. 2;

FIG. 4 a shows a section through the peristaltic pump according to FIG. 2 along the plane A-A;

FIG. 4 b shows a detail of a section through the peristaltic pump according to FIG. 2 in the region of the counter bearing and a guide roller situated opposite the counter bearing, and

FIG. 5 shows a perspective representation of the threading device of the peristaltic pump according to FIG. 2.

FIG. 1 shows the injection head of an injection device for injecting two different or identical contrast agents and a NaCl rinsing solution into the bloodstream of a patient, wherein an inventive peristaltic pump 1 is utilized in said injection device. Such injection devices are used, e.g., for injecting contrast agents while carrying out imaging processes such as computer-assisted tomography, ultrasonic examinations and magnetic resonance tomography (MRT). The injection device comprises the injection head 20 illustrated in FIG. 1, in which the peristaltic pump 1 is arranged. The injection head 20 comprises a plastic housing with two annular handles 21, 22. A panel 23 is arranged between the handles 21 and 22 and can be closed with a cover that is not illustrated in this figure. In its lower region, the panel 23 features a recess for accommodating the peristaltic pump 1. Channel- shaped recesses 24, 25, into which a branched hose arrangement (that is not illustrated in this figure) can be inserted, are situated above the aforementioned recess. The hose arrangement consists in particular, of a hose arrangement of the type described in detail in EP 2 011 541 A2. This hose arrangement comprises a total of three supply hoses, namely a first supply hose for a first contrast agent, a second supply hose for a second contrast agent and a third supply hose for a rinsing solution (particularly NaCl). The three supply hoses are connected to supply bottles for the contrast agent and the rinsing solution, which are also not illustrated in this figure, and are inserted into the branches 24 a, 24 b and 24 c of the recess 24 that are arranged in the upper region of the panel 23. A junction element inserted into the circular recess 24 d of the panel 23 combines the three supply hoses connected to the supply containers into one hose section that is routed to the peristaltic pump 1.
A threading device is provided for inserting the hose into the peristaltic pump 1. The function and the design of this threading device are described below. The hose is ultimately routed through the peristaltic pump 1 and placed into the recess 25 in the upper left part of the panel 23. The hose end is connected to a patient hose, through which the mediums carried in the hose can ultimately be injected into the bloodstream of the patient. A fixing device is provided for fixing the hose on the panel 23, wherein this fixing device makes it possible to fix the hose at a first location 39 on the intake side and at least one second location 40 on the output side of the peristaltic pump. Ultrasonic sensors for detecting air bubbles in the hose are advantageously arranged at the fixing points 39 and 40. Other fixing points for fixing the hose on the panel 23 can be provided and are described, e.g., in EP 2011541 A1.
In FIGS. 2 and 3, the peristaltic pump 1 is illustrated in detail in the form of a perspective representation, wherein FIG. 3 shows an exploded view. The peristaltic pump 1 comprises a lower pump unit with a driving motor 7, as well as an upper pump unit with a housing 2. The housing 2 is divided into a lower housing part 2 a and an upper housing part 2 b. The lower housing part 2 a and the upper housing part 2 b may be realized integrally or in the form of two separate parts.
The lower pump unit comprises the driving motor 7 with a driveshaft 10 that is coupled to the upper pump unit via a gear mechanism. The design of the upper pump unit is illustrated in the form of a sectional representation in FIG. 4. A gear mechanism 6 coupled to the driveshaft 10 of the driving motor 7 is arranged in the interior of the housing 2. The gear mechanism comprises a sun wheel 30 that is connected to the driveshaft 10 of the driving motor 7 in a rotationally rigid fashion. The upper end of the driveshaft 10 is rotatably supported in a carrier disk 8 by means of a bearing 43. Several squeezing elements 3 are arranged on the carrier disk 8. In the exemplary embodiment shown, the squeezing elements 3 consist of driven squeezing rollers 3, wherein three squeezing rollers 3 of this type are uniformly arranged on the outer circumference of the circular carrier disk 8. The squeezing rollers 3 are rotatably supported on the carrier disk 8. For this purpose, each of the three squeezing rollers 3 is placed on a shaft 9 with an axis 9′ and each shaft 9 is supported in a bore of the carrier disk 8 by means of a bearing 15. The shafts 9 and therefore the axes 9′ of the squeezing rollers 3 extend parallel to the driveshaft 10 of the driving motor 7. During the operation of the pump, the driving motor 7 sets the carrier disk 8 and the squeezing rollers 3 in rotation via the gear mechanism 6. The gear mechanism 6 comprises planetary wheels 16 in addition to the sun wheel 30, wherein such a planetary wheel 16 is assigned to each squeezing roller 3 and fixed on the shaft 9 in a rotationally rigid fashion. Each of the planetary wheels 16 is coupled to the sun wheel 30 of the epicyclic gear by means of a toothing. A friction wheel 31 is arranged on each shaft 9 adjacent to the planetary wheel 16, wherein the friction wheel 31 is fixed on the shaft 9 in a rotationally rigid fashion and at a distance from the planetary wheel 16. A circumferential groove 34 is arranged on the outer circumference of each friction wheel 31 and a rubber ring 32 (O-ring) is inserted into said groove. The friction wheel 31 is in contact with the inner circumference 2 c of the pump housing 2 via this rubber ring 32. The inner circumference 2 c of the housing 2 therefore acts as a crown wheel of the epicyclic gear. When the driveshaft 10 is set in rotation by the driving motor 7, this rotary motion is transmitted to the shaft 9 via the coupling between the planetary wheel 16 and the sun wheel 30 such that the shaft 9 and the squeezing roller 3 connected thereto in a rotationally rigid fashion are set in rotation. The friction wheel 31 simultaneously rolls on the inner circumference 2 c of the pump housing 2, whereby the carrier disk 8 likewise moves in rotation against the pump housing 2. Due to the friction wheels 31, the carrier disk 8 can also be set in rotation by the driving motor 7 if a hose is not yet inserted into the peristaltic pump.
Guide rollers 11 are also supported on the carrier disk 8 in addition to the squeezing rollers 3. The guide rollers 11 serve for guiding the hose between adjacent squeezing rollers 3 and are not driven. On their outer circumference, the guide rollers 11 feature a groove 34 of semicircular cross section, in which the hose is guided. The arrangement of the guide rollers 11 and the squeezing rollers 3 on the carrier disk 8 is illustrated in particular in the exploded view according to FIG. 3.
In order to insert the hose into the peristaltic pump, a threading device is provided that automatically threads the hose between the squeezing rollers 3 and the counter bearing 4. The threading device comprises a screw spindle 26 that is arranged outside the carrier disk 8. The screw spindle 26 is arranged on a shaft 27, wherein the shaft 27 extends parallel to the axis 9′ of the squeezing rollers 3. The shaft 27 is rotatably supported in a housing part 2 of the peristaltic pump and coupled to a spindle drive 28, by means of which the shaft 27 and the screw spindle 26 can be set in rotation in order to thread a hose placed into the screw spindle in the peristaltic pump. The upper flights of the screw spindle 26 protrude over the upper side of the squeezing rollers 3 and the guide rollers 11 in the longitudinal direction of the peristaltic pump (i.e., parallel to the axis of the respective shafts 10 and 27).
The counter bearing 4 is arranged on the upper end of the upper pump unit. The counter bearing 4 has the shape of a segment of a circle with a recess 38 and advantageously extends over an angular range of 200° to 300°. The screw spindle 26 is arranged in the region of the recess 38 of the counter bearing 4. The counter bearing 4 features an effective surface 4 a that lies opposite the outer circumference of the squeezing rollers 3 and is spaced apart from this outer circumference by a distance d. The hose is threaded into the gap between the effective surface 4 and the outer circumference of each squeezing roller 3.
In order to insert the hose into the peristaltic pump 1, the hose section to be inserted is initially fixed on the panel 23 at the two fixing points 39 and 40 by means of the fixing device. The hose section between the fixing devices 39 and 40 then has the shape of a loop (due to the natural twist of the hose section). The hose section is subsequently placed into the screw spindle 26. The pump is then set in motion such that the driving motor 7 rotates the carrier disk 8. The spindle drive 28 simultaneously sets the screw spindle 26 in rotation. For this purpose, the spindle drive 28 is coupled to the control of the driving motor 7. The rotation of the screw spindle 26 causes the screw spindle 26 to guide the hose downward in the direction of the carrier disk 8. Due to the rotation of the carrier disk, one of the guide rollers 11 is moved toward the hose and the hose engages into the groove 34 on the outer circumference of the guide rollers 11. As the carrier disk 8 continues to rotate, the guide roller 11 arranged thereon moves in the conveying direction of the pump and pulls the hose downward in the direction of the carrier disk 8 due to the frictional engagement in the groove 34 and simultaneously presses the hose radially outward against the counter bearing 4 due to the positive fit. As the rotation of the carrier disk 8 continues, the guide roller 11 pulls the hose further into the peristaltic pump along the inner circumference of the counter bearing 4 with the shape of a segment of a circle due to the static friction on the hose surface and the frictional engagement in the groove 34 on its outer circumference, namely until the carrier disk with the guide roller 11 arranged thereon has carried out (nearly) one complete revolution and the hose has been completely pulled into the peristaltic pump due to the continued rotation of the carrier disk. The rotation of the carrier disk ultimately causes the hose to be squeezed against the counter bearing 4 by the squeezing roller 3 that follows the guide roller 11 on the carrier disk 8. In this way, the hose is automatically inserted between the outer circumference of the squeezing rollers 3 and the counter bearing 4 and squeezed as the carrier disk 8 continues to rotate in order to convey the liquid carried therein.
Once the hose is completely inserted into the peristaltic pump, the squeezing rollers 3 press the hose against the effective surface 4 a of the counter bearing 4 during the operation of the peristaltic pump (i.e., when the carrier disk 8 rotates and the squeezing rollers 3 rotate) in order to squeeze the hose diameter and thusly convey the medium in the hose onward in the conveying direction (i.e., in the rotating direction of the carrier disk 8).
After the pumping operation is completed, the threading device can also be used for unthreading the used hose during a required hose change. For this purpose, the spindle drive 28 rotates in the opposite rotating direction during the operation of the peristaltic pump. Consequently, the screw spindle 26 pulls the hose section inserted into the peristaltic pump upward such that the hose is disengaged from the groove 34 of the guide rollers 11. After one complete revolution of the carrier disk, the hose is completely pulled out of the peristaltic pump, wherein the hose can be removed after loosening the fixing devices at the fixing points 39 and 40 and ultimately replaced with a new hose. A control routine for initiating the unthreading of the used hose is provided in the control of the spindle drive 28 and can be activated by the operator when a corresponding button is pushed.
In order to optimally adjust the distance between the counter bearing 4 and the squeezing rollers 3, the counter bearing with its effective surface 4 a is in one preferred exemplary embodiment arranged on the housing 2 such that it can be displaced relative to the squeezing rollers 3. For this purpose, the counter bearing 4 is connected to a thrust collar 13. The thrust collar 13 also consists of a ring with the shape of a segment of a circle. The counter element 4 features an adjustment surface 4 b that lies opposite the effective surface 4 a. It is realized in a conical or cone-shaped fashion. The arrangement consisting of the counter element 4 and the thrust collar 13 is arranged in the upper opening of the housing 2 in such a way that the conical adjustment surface 4 b of the counter element 4 is braced against a complementary (i.e., also conical or cone-shaped) support surface 5 on the housing 2, wherein the support surface 5 on the housing 2 conically widens (upper left side of FIG. 4) downward, (i.e., into the housing interior).
A mounting ring 36 with mounting flanges 37 that is fixed on the housing (and not illustrated in FIG. 3 in order to provide a better overview) is provided on the outer side of the housing 2 in order to mount the housing 2 on the panel 23 of the injection head 20. An adjustment ring 12 is furthermore arranged on the outer side of the housing 2 in the transition area between the lower housing part 2 a and the upper housing part 2 b. The adjustment ring 12 consists of a circular ring that features an internal thread on its inner circular surface. An external thread realized complementary to this internal thread is provided on the outer side of the housing 2. The adjustment ring is coupled to the housing 2 by means of this thread arrangement in such a way that the adjustment ring can be continuously displaced in the axial direction between an uppermost position and a lowermost position referred to the housing 2 by turning the adjustment ring 12 relative to the housing 2. In order to turn the adjustment ring 12 relative to the housing 2, the outer circumference of the adjustment ring 12 is provided with several bores 33, into which a pin can engage.
A displacement ring 14 adjoins the underside of the adjustment ring 12. The displacement ring 14 is composed of two semicircular ring segments 14 a and 14 b and connected to the thrust collar 13 by means of several bolts 29 (FIG. 3).
The distance d between the squeezing rollers 3 and the effective surface 4 a of the counter bearing 4 can be adjusted with the arrangement consisting of the counter bearing 4, the thrust collar 13, the displacement ring 14 and the adjustment ring 12.
In order to maximize the distance d between the outer circumference of the squeezing rollers 3 and the effective surface 4 a, the counter bearing 4 is moved into its first (uppermost) position. Based on this position, the distance d can be reduced by turning the adjustment ring 12 on the housing 2 in the direction of its lowermost position. This causes the adjustment ring 12 to be displaced downward from its uppermost position. Consequently, the displacement ring 14 that adjoins the underside of the adjustment ring 12 is also displaced downward relative to the housing. Since the displacement ring 14 is connected to the thrust collar 13 by means of the bolts 29, the thrust collar 13 with the counter bearing 4 fixed thereon is also displaced downward. The adjustment surface 4 b of the counter bearing 4 slides along the conical support surface 5 on the housing 2 in this case. During this motion, the counter bearing 4 with the shape of a segment of a circle slightly contracts and reduces its diameter such that the effective surface 4 a is pressed toward the squeezing rollers 3 and the guide rollers 11 in the radial direction. This motion causes the distance d between the effective surface 4 a and the outer circumference of the squeezing rollers 3 to be reduced. Once the adjustment ring 12 reaches its lowermost position, the underside of the thrust collar 13 rests on a base 31 of the housing 2. In this position, the minimum distance d between the effective surface 4 a and the respective outer circumference of the squeezing rollers 3 and the guide rollers 11 is adjusted.
Due to this arrangement of the counter bearing 4, the gap size (i.e., the distance d) between the effective surface 4 a and the outer circumference of the squeezing rollers 3 can be adjusted to an optimal value for the operation of the pump. This adjustment is initially carried out before the peristaltic pump is put into service. A gauge, the thickness of which corresponds to the gap size to be adjusted, is advantageously inserted between the effective surface 4 a and the outer circumference of the squeezing rollers 3 in order to adjust a desired distance d. Subsequently, the adjustment ring 12 is turned relative to the housing until the effective surface 4 a and the outer circumference of the squeezing rollers 3 adjoin the outer surfaces of the gauge. If so required, the gap size can be readjusted when the peristaltic pump is serviced.
The invention is not limited to the described exemplary embodiment. For example, the invention is not only suitable for use in radial peristaltic pumps, but also, e.g., in peristaltic pumps with a linearly acting system such as, for example, so-called linear peristaltic pumps or traveling-wave pumps. Furthermore, the inventive peristaltic pump is not only suitable for use in injection devices, but also in other pumping devices such as, e.g., infusion pumps. Instead of the screw spindle, the threading device may also feature a gripper with a linear drive, wherein the gripper takes hold of or encompasses the hose or the hose section placed into the threading device and the linear drive subsequently guides the hose downward in the direction of the carrier disk such that it can be carried along by the guide rollers in the above-described fashion and inserted into the peristaltic pump between the counter bearing and the squeezing rollers around the counter bearing. In this case, the linear drive may be realized in the form of a linear motor or a revolving cylinder engine with transmission gearing for converting the rotary motion into a linear motion. As an alternative to a motor drive, it would also be possible to use a bistable magnet for setting the threading device in motion and thusly insert the hose into the pump. Furthermore, holding fins may be used instead of guide rollers, wherein said holding fins are arranged on the carrier plate and press the hose section inserted into the pump by the threading device downward in the direction of the carrier disk and radially outward in the direction of the counter bearing.

Claims

1. A peristaltic pump for conveying a medium carried in a hose, comprising several squeezing elements that press the hose against a counter bearing to squeeze the hose and convey the medium in the hose onward in a conveying direction, wherein the peristaltic pump includes a threading device for automatically inserting the hose between the squeezing elements and the counter bearing, the threading device including a screw spindle.

2. The peristaltic pump according to claim 1, wherein the squeezing elements comprise squeezing rollers set in rotation by a driving motor via a gear mechanism.

3. The peristaltic pump according to claim 2, wherein the squeezing rollers are supported on a carrier disk, in which an axis of each squeezing roller extends parallel to a drive shaft of driving motor.

4. The peristaltic pump according to claim 3, wherein the carrier disk and the squeezing rollers rotatably supported therein are set in rotation by the driving motor via a gear mechanism during operation of the peristaltic pump.

5. The peristaltic pump according to claim 4, wherein a guide roller is respectively arranged between two adjacent squeezing rollers on the carrier disk.

6. The peristaltic pump according to claim 3, wherein the threading device is arranged outside the carrier disk.

7. The peristaltic pump according to claim 1, wherein the screw spindle can be rotatively driven by a spindle driver.

8. The peristaltic pump according to claim 7, wherein the spindle driver is coupled to the driving motor in such a way that the spindle driver sets the screw spindle in rotation as soon as the driving motor rotates the carrier disk.

9. The peristaltic pump according to claim 8, wherein the screw spindle is arranged on a shaft, the shaft rotationally rigid and extending parallel to axis of the squeezing rollers.

10. The peristaltic pump according to claim 9, wherein the shaft is rotatably supported in a housing part of the peristaltic pump.

11. The peristaltic pump according to claim 1, wherein the threading device automatically inserts the hose between the squeezing elements and the counter bearing during operation of the peristaltic pump.

12. The peristaltic pump according to claim 1, further comprising a fixing device for fixing the hose to a first location on an intake side of the peristaltic pump and to a second location on an output side of the peristaltic pump.

13. The peristaltic pump according to claim 1, wherein the counter bearing is formed as a ring in a shape of a segment of a circle with a recess and the screw spindle is arranged in a region of the recess.

14. The peristaltic pump according to claim 2, wherein the gear mechanism comprises a sun wheel and at least one planetary wheel connected to a respective squeezing roller in a rotationally rigid form and the carrier disk is set in rotation by the drive via an epicyclic gear including the sun wheel and at least one planetary wheel for each squeezing roller during operation of the peristaltic pump, wherein the at least one planetary wheel is coupled to an inner circumference of a housing that acts as a crown wheel.

15. The peristaltic pump according to claim 14, wherein the sun wheel is connected to a driveshaft of the drive in a rotationally rigid form and torque transmitted from the driveshaft to the sun wheel is transmitted to the carrier disk by the sun wheel via inner circumference of the housing that acts as a crown wheel, wherein the carrier disk is set in rotation without an inserted hose during operation of the peristaltic pump.