EP3879104B1 - Hose pump - Google Patents

Description

The invention relates to a hose pump according to the preamble of claim 1 and to a method for threading a hose into a hose bed of a hose pump.

Such peristaltic pumps are, for example, from U.S. 2009/263256 A1 , the U.S. 2013/045122 A1 , the DE 20 2016 101 907 U1 and the EP 2 924 288 A2 known. These known hose pumps have a hose bed into which a hose section of a hose bent in the shape of a loop can be inserted. The known peristaltic pumps also include a counter bearing and a carrier disk which can be rotated relative to the counter bearing and on the upper side of which a plurality of squeezing rollers and a plurality of guide rollers are arranged. Both the squeezing rollers and the guide rollers are arranged equidistant from one another in the radially outer region of the carrier disk and in the circumferential direction of the carrier disk, with one guide roller being arranged between two successive squeezing rollers in the circumferential direction of the carrier disk. In one exemplary embodiment of the known peristaltic pumps, three squeezing rollers and three guide rollers are provided, each of which has an angular spacing of 60° from the adjacent squeezing roller or guide roller in the circumferential direction of the carrier disk. The squeezing rollers have a smooth outer circumference and, when the carrier disk rotates in a conveying direction, press a hose placed in the hose bed while squeezing the hose against the counter bearing in order to transport a fluid in the hose in the conveying direction. The cylindrical guide rollers have a circumferential guide groove on their outer circumference for receiving the radially inner hose half of the hose section and ensure exact positioning and guidance of the hose in the hose bed both when threading the hose section into the hose bed and during pumping operation.

From the DE 21 62 998 A1 a peristaltic hose pump with several successive pressure rollers and guide rollers is known, the guide rollers having a profile whose contours ensure smooth guidance starting from the diameter of the hose used up to its greatest squeezed width, with the guide rollers being designed for two peristaltic hoses in one embodiment and for this have two circumferential guide grooves on its outer circumference, in each of which a hose can be guided.

A motor-driven device with a worm spindle can be used for automatically threading the hose section in and out of the hose bed, as is the case, for example, in EP 2 542 781 A1 is described. However, such a motor-operated device for threading the hose in and out is expensive. As an alternative to this, the tube section can also be pressed with a hold-down device against a support surface at the entrance of the tube bed for threading into the tube bed and, with the carrier disk rotating, gripped by one of the guide rollers and thereby pulled into the tube bed, with the radially inner area of the tube section being received in the guide groove of the guide roller and being pressed downwards in the axial direction onto a support surface in the tube bed. Problems can arise if the hose section is too short or too long. If the hose section is too short, there is a risk that the hose section will be stretched too much when it is threaded in and it will slip out of the guide groove of the guide roller. If the hose section is too long, problems can arise both when threading the hose into the hose bed and when operating the hose pump, because the hose section at the outlet of the hose bed forms a loop that protrudes over the bearing surface of the hose bed and is therefore not guided cleanly in the hose bed. During operation of the peristaltic pump, particularly at very high pump pressures, which can reach up to 20 bar during normal operation, the downstream end of a hose section that is too long can slip out of the guide groove of the guide rollers and thereby lift off the contact surface of the hose bed. This can lead to the hose section automatically and unintentionally threading out during operation of the hose pump and becoming tangled in the process. This can block the peristaltic pump.

Furthermore, it has been shown that the problems described when threading the hose also depend very strongly on the mechanical properties of the hose, in particular on its extensibility and friction properties. The mechanical properties of the hose depend on many different factors, such as the material composition, the age and the pre-treatment of the hose, e.g. cleaning and sterilization. The material properties of the hose can also change in the Change over time during storage, e.g. due to the escape of material components, in particular the plasticizers contained in the plastic composition. The behavior of a hose when threading it in and out can therefore be very different, which makes it considerably more difficult to thread in and thread out different hoses correctly.

Proceeding from this, the invention is based on the object of further developing a hose pump of the generic type in such a way that hose sections of different pump hoses, in particular different pump hoses with different material compositions and different material properties, can be reliably threaded in and out.

In particular, a secure threading in and out of a hose section of the hose in the hose bed of the hose pump should also be ensured if the hose section is a little too short or too long compared to the inner circumference of the counter bearing. Furthermore, it should be prevented that during operation of the peristaltic pump, in particular at high pump pressures, the inserted hose section does not unthread itself and that the hose pump cannot become blocked if the hose is accidentally unthreaded during the threading-in process or during pump operation.

These objects are achieved with a hose pump having the features of claim 1 and with the method of claim 12. Preferred embodiments of the hose pump and the method can be found in the dependent claims.

The hose pump according to the invention has a hose bed for inserting a hose section of a pump hose, an abutment, a carrier disk which can be rotated relative to the abutment, a plurality of squeezing rollers which are preferably arranged equidistantly from one another in the circumferential direction on the carrier disk and a plurality of guide rollers which are preferably arranged equidistant from one another in the circumferential direction on the carrier disk and have a guide groove running around their outer circumference in the circumferential direction, which forms a first guide plane facing the carrier disk. According to the invention, each guide roller has one of the above the guide groove Carrier disc facing away from the guide cylinder for the initial guidance of the hose when threading into the hose bed and / or when unthreading from the hose bed.

The guide cylinder of the guide rollers is used when threading the hose into the hose bed for the initial guidance of the hose and, when the carrier disk rotates in a conveying direction, enables the hose to be reliably guided initially and reliably inserted into the guide grooves of the guide rollers, which face the carrier disk and ensure that the hose is guided in the hose bed in a precisely positioned manner during operation of the hose pump when the carrier disk is rotating in a conveying direction.

To thread the hose into the hose bed of the peristaltic pump, the hose is first placed in a second guide plane formed by the guide cylinders of the guide rollers, facing away from the carrier disk, and then the carrier disk is rotated in the conveying direction. In this case, the hose is brought from the second guide level in the axial direction towards the carrier disc into the first guide level defined by the guide grooves. The hose section that was initially placed in the second guidance level can be pressed down in the direction of the surface of the carrier disk when it is being threaded into an area at the entrance to the hose bed, either manually by an operator or by means of a mechanical hold-down device on the hose pump, in order to ensure that when the carrier disk rotates, the hose section that has been inserted is gripped by (at least) one guide roller and transferred from the upper second guidance level down to the first guidance level.

The squeezing rollers of the hose pump according to the invention are expediently at least essentially cylindrical and have a smooth outer surface, with the outer circumference of the cylindrical squeezing rollers pressing the hose against the counter bearing in order to transport fluid in the hose in the conveying direction.

The guide groove running around the outer circumference of the guide rollers is preferably adapted to the shape of the hose and the guide groove can have an at least essentially semicircular cross section, in particular for a hose with a circular cross section. Due to the semicircular shape of the guide groove on the outer circumference of the guide rollers, these nestle against the hose pump during operation surface of the hose without squeezing it. This ensures that the hose is guided safely and consistently in the hose bed when the hose pump is running.

According to the invention, an annular flange running around the outer circumference of the guide roller is arranged on each guide roller between the guide groove and the guide cylinder arranged above the guide groove. This annular flange separates the guide groove from the guide cylinder of the respective guide roller and thereby defines the first guide plane facing the carrier disc in the area of the guide grooves and the second guide plane facing away from the carrier disc in the area of the guide cylinders of the guide rollers. The second management level is offset axially to the first management level and is arranged above the first management level. When we speak here of above or above, this means a direction that is perpendicular to the surface of the carrier disk, which forms a guide surface for a hose placed in the hose bed. There are no restrictions with regard to the orientation of the peristaltic pump, because it can be operated both in a horizontal and in a vertical position of the carrier disk.

The formation of an upper, second guide level facing away from the carrier disk enables the operator of the hose pump to initially insert the hose section to be threaded easily and without hindrance into the upper, second guide level when threading in the hose, with the hose section inserted therein being guided initially. The guide cylinder around which the inserted hose section is placed exerts a prestress on the hose in its longitudinal direction, as a result of which the hose is stretched slightly, depending on the stretching properties. To thread the inserted tube section into the tube bed, the carrier disk is then rotated in the conveying direction, with a first guide roller gripping the tube section at an inlet of the tube bed. Due to the pretensioning of the hose, when the carrier disk is rotated, it is pulled from the upper, second guide level downwards towards the carrier disk into the lower, first guide level (while slightly stretching the hose) until the area of the inserted hose section at the entrance to the hose bed engages in the guide groove of the first guide roller. With further rotation of the carrier disk in the conveying direction, the inserted tube section is in this way over the entire circumference of the carrier disk brought from the upper, second management level to the lower, first management level, until the inserted tube section comes to rest neatly in the guide groove of all guide rollers and is thus inserted in the tube bed ready for operation.

The pretension exerted by the guide cylinders of the guide rollers on the inserted hose section ensures that the hose has as little contact as possible with the counter bearing when being threaded in. This prevents the hose from rubbing against the counter bearing and the different friction properties of different hoses from having a (negative) influence on the threading of the hose. This means that the threading process is largely independent of the mechanical properties of the hose. This enables the same and safe threading of different hoses with possibly different material parameters as well as a material-friendly threading of the hose.

A particularly reliable initial guidance of the hose when threading in is achieved if the second guide level includes a half-groove running around the outer circumference of the guide roller, because the inserted hose section can nestle well against the preferred half-groove shape of the second guide level. The half-groove design of the second guide level, which in particular has a quarter-circle cross-section, also enables a simple and unimpeded insertion of a hose section to be threaded into the upper, second guide level.

The height of the guide cylinders of the guide rollers, ie the distance between the front top side of the guide cylinder and the annular flange, is preferably at least as great as the diameter of the hose for each guide roller. This also ensures good initial guidance of the hose in the second guidance level when threading in, because the hose is guided over its entire diameter by the guide cylinder.

The squeezing rollers are preferably at least essentially cylindrical with a flat upper side, with the guide cylinders of the guide rollers preferably being located above the upper side of the squeezing rollers in the axial direction. This prevents the inserted hose section from getting tangled up when threading in or during operation of the hose pump and thereby blocking the hose pump. Furthermore This arrangement enables a hose section to be threaded into the hose bed to be inserted into the second guide level without hindrance.

The hose pump according to the invention is designed for operation with a single hose. Correspondingly, for the operation of the peristaltic pump (only) one hose is inserted into the hose bed, so that the squeezing rollers press the hose against the counter bearing with the rotating carrier disk while squeezing the hose in order to transport any fluid in the hose in the conveying direction.

In a preferred embodiment of the peristaltic pump, the annular flange between the guide groove and the guide cylinder is arranged axially offset upwards away from the carrier disk in at least one guide roller of the plurality of guide rollers compared to the annular flange of the other guide rollers. When the hose is threaded in while the carrier disk is rotated, this ensures that the hose section placed in the upper, second guide level is securely caught by this guide roller with an annular flange that is offset axially upwards, because the annular flange that is offset somewhat upwards creates an enlargement of the insertion cross-section of the guide groove of this guide roller, thereby enabling the hose section to be gripped more easily at the entrance to the hose bed. This ensures that the hose section placed in the upper, second guide level is always caught by this guide roller with the annular flange offset axially upwards when the carrier disc rotates and is pulled down into the lower, first guide level, even if the guide rollers that may be upstream in the conveying direction have not properly gripped the hose and pulled it down into the first guide level. At the same time, unhindered threading out of the tube is ensured when the carrier disk rotates counter to the conveying direction, which will be explained in detail further below.

As already mentioned above, a hose section threaded into the hose bed is reliably guided during operation of the hose pump if the guide groove of at least one or each guide roller has at least a partially circular, in particular a semicircular, cross section. The cross-section of the guide roller with the annular flange offset axially upwards can also expediently deviate from a partial or semi-circular cross-section form an enlarged introduction cross-section in the area of the lower, first management level.

Due to the axial offset, the guide roller with the annular flange offset axially upwards has an enlarged insertion cross-section in the area of the lower, first guide level compared to the other guide rollers and therefore makes it easier to transfer the hose from the upper, second guide level to the lower, first guide level than the other guide rollers. The other guide rollers, on the other hand, ensure that when the hose is being fed out (which occurs when the carrier disc is rotated counter to the conveying direction), the annular flange, which is axially offset somewhat downwards towards the carrier disc, can run under the hose section in the area of the outlet of the hose bed during the feed-out process and thus lift it from the lower, first guide level to the upper, second guide level.

In order to support the annular flange of at least one of the guide rollers when the hose is being fed out while the carrier disk is rotated counter to the conveying direction, the hose section inserted in the hose bed is driven under by the annular flange of at least one of the guide rollers.

In order to prevent a hose section from being able to lie in a radially inner area (seen in relation to the carrier disk) of the outer circumference of the guide rollers when the hose is being threaded in and therefore not being correctly caught by this guide roller and being inserted into the hose bed between the outer circumference of the guide roller and the counter bearing, a cover lying on top of the guide rollers and covering the guide rollers is expediently provided. The cover is preferably designed in the shape of a cross or a star and has indentations, in particular in the area between two adjacent guide rollers, which in particular can be shaped in a convex or part-circular manner. The indentations are used for manually gripping the cover, so that an operator can grip the cover in an ergonomically optimized manner and manually set the carrier disk in rotation by exerting a torque on the cover and via the guide rollers attached thereto. This allows manual rotation of the carrier disc when threading the hose in or out without having to use the pump's motor. The lid can instead of Indentations also have bulges, which in particular can be convex or part-circular. Furthermore, openings can also be provided in the cover, into which an operator can insert one or more fingers (in the manner of a dial) to manually turn the carrier disk.

In order to rotate the carrier disk during operation of the pump, the carrier disk is preferably connected to a shaft which is coupled to a motor and can be rotated by the motor. The guide rollers and the squeezing rollers are preferably rotatably mounted on the carrier disk in order to enable friction-free rolling on the surface of the tube. However, they can also each be connected to the carrier disk in a rotationally fixed manner. The axis of rotation of the carrier disc (axis of the shaft) and the axes of the pinch rollers and the guide rollers run parallel to one another. If the guide rollers and the squeezing rollers are rotatably mounted on the carrier disc, they can be rotated by the motor (possibly via a gear). However, the guide rollers and the squeezing rollers can also be rotatably mounted on the carrier disk without being coupled to a drive (passively).

If the guide rollers, which are arranged rotatably on the carrier disc, are actively rotated by the motor, the hose can be safely transferred from the upper, second guide level to the lower, first guide level during threading if the annular flange is simultaneously inclined in the conveying direction in a helical manner in the direction of the carrier disc. In such an embodiment, the hose section inserted into the second guide level is brought from the upper, second guide level to the lower, first guide level by the downwardly spiraled annular flange when the carrier disk rotates and the guide rollers simultaneously rotate actively in relation to the carrier disk.

In a preferred arrangement, a guide roller is arranged between two successive squeezing rollers in the circumferential direction on the carrier disk, with the squeezing rollers pressing a hose (or hose section) placed in the hose bed (or hose section) placed in the hose bed while squeezing the hose against the counter bearing in order to transport a fluid located in the hose in the conveying direction. This preferred arrangement ensures that the hose is guided cleanly over the entire circumference of the carrier disk when the hose pump is in operation.

It is advantageous if the distance between the pinch and guide rollers is not equidistant (that is, asymmetrical) over the circumference of the carrier disk. In a preferred embodiment of the peristaltic pump according to the invention, the guide rollers are each set back in relation to the squeezing rollers that follow them in the conveying direction (direction of rotation of the carrier disk during pump operation of the peristaltic pump), i.e. the angular distance (δ) between a guide roller and the squeezing roller that follows this guide roller in the conveying direction is smaller than the angular distance (Δ) between this guide roller and the squeezing roller that precedes this guide roller in the conveying direction. This arrangement of the rolling troke and the guide rolls on the carrier disc when threading the hose into the hose bed prevents the current -up -to -power section of the hose from the guide groove from the guide groove of a guide role, because the guide roller when the carrier disc is turned directly, i.e. with only slight angular distance δ, follows the troke that is controlled against the tube. Ager presses and thereby fixes the position of the section of the hose already inserted into the hose bed in the hose bed.

During pumping operation of the peristaltic pump, the preferred asymmetrical arrangement of the pinch rollers and the guide rollers on the carrier disc prevents the hose from being unthreaded unintentionally, because each pinch roller is immediately preceded by a guide roller when the carrier disc is rotated, i.e. at only a small angular distance δ, which holds the downstream section of the hose securely in the hose bed even at high pump pressures and prevents the downstream end of the hose from bulging into a loop at the outlet of the hose bed , while the section of the hose lying somewhat further back, viewed in the conveying direction, is pressed by the squeezing roller against the counter bearing.

The magnitude of the relative angular difference (Δ−δ/Δ+δ) between the angular distance Δ between a guide roller and the squeezing roller preceding this guide roller in the conveying direction and the angular distance δ between this guide roller and the squeezing roller following this guide roller in the conveying direction is in the range from 0.2 to 0.5.

The guide rollers and the squeezing rollers are expediently distributed rotationally symmetrically (with respect to the axis of rotation of the carrier disk as the center of symmetry) on the carrier disk, the angle of symmetry being 360°/n when n is the number of guide rollers or squeezing rollers.

In a preferred embodiment, the hose pump according to the invention has three or more squeezing rollers and an equal number of guide rollers, which are arranged on the radially outer edge of the carrier disk in such a way that the angular distance (δ) between each guide roller and the squeezing roller following a guide roller in the conveying direction is less than 60° and in particular - with three guide rollers and three squeezing rollers - is preferably 45°. Correspondingly, the angular distance (Δ) between a guide roller and the squeezing roller preceding this guide roller in the conveying direction is greater than 60° and is in particular at least 75°. In this arrangement with three pinch rollers and three guide rollers, the magnitude of the relative angle difference is preferably Δ−δ/Δ+δ=0.25. In an alternative arrangement with four pinch rollers and four guide rollers, the magnitude of the relative angle difference is preferably Δ−δ/Δ+δ=0.33.

The hose pump according to the invention preferably comprises a device for monitoring the threading process when threading a hose into the hose bed. A device for monitoring the threading process that is particularly easy to implement includes a device for detecting the torque acting on the carrier disk. By detecting the torque acting on the carrier disk, it can be determined in a simple and reliable manner whether the hose is properly threaded. When the hose is properly threaded, the torque on the carrier disk increases because the motor that rotates the carrier disk runs against a higher rotational resistance.

To indicate that the threading process has been completed properly, a signal generator is preferably provided, which outputs a first signal when a torque threshold value is exceeded. In order to indicate faulty or improper threading, the signal transmitter can also be set up such that a second signal is output after a specified period of time has elapsed if the torque threshold value has not been reached or exceeded within this period of time. In this way he gets The operator of the hose pump according to the invention expediently receives information about the state of the hose pump or the status of the threading process during each threading process.

The status of the threading process determined by the device for monitoring the threading process can also be used to control an automatic threading routine, for example by automatically starting another threading process after a failed threading process. The same preferably also applies to the unthreading of the hose, in which case it is concluded that the hose has been successfully unthreaded if the torque falls below a threshold value.

• Figur 1 : Perspektivische Darstellung einer erfindungsgemäßen Schlauchpumpe mit darin eingelegtem Schlauch, wobei der Schlauch in einer Parkposition vor dem Einfädeln oder nach dem Ausfädeln gezeigt ist;
• Figur 2 : Querschnitt der Schlauchpumpe von Figur 1 (Schnittebene mittig durch eine untere Führungsebene der Führungsrollen);
• Figur 3 : Detaildarstellung der Trägerscheibe mit den darauf angeordneten Quetsch- und Führungsrollen der Schlauchpumpe von Figur 1 in einer perspektivischen Ansicht;
• Figur 4 : Seitenansicht der Trägerscheibe mit den darauf angeordneten Quetsch- und Führungsrollen der Schlauchpumpe von Figur 1;
• Figuren 5 bis 8 : Darstellung der Schritte eines Einfädelvorgangs zum Einfädeln des Schlauchs in das Schlauchbett der Schlauchpumpe von Figur 1;
• Figur 9 : Darstellung eines Ausfädelvorgangs zum Ausfädeln des Schlauchs aus dem Schlauchbett der Schlauchpumpe von Figur 1;

These and other advantages and features of the hose pump according to the invention result from the exemplary embodiment described in more detail below with reference to the accompanying drawings. The drawings show:

• figure 1 : Perspective view of a hose pump according to the invention with a hose inserted therein, the hose being shown in a parked position before threading in or after threading out;
• figure 2 : Cross section of the peristaltic pump from figure 1 (Sectional plane centered through a lower management level of the guide rollers);
• figure 3 : Detailed view of the carrier disc with the squeezing and guide rollers of the peristaltic pump from figure 1 in a perspective view;
• figure 4 : Side view of the carrier disk with the squeezing and guide rollers of the peristaltic pump arranged on it figure 1 ;
• Figures 5 to 8 : Representation of the steps of a threading process for threading the hose into the hose bed of the hose pump from figure 1 ;
• figure 9 : Representation of a process of threading out the hose from the hose bed of the hose pump from figure 1 ;

In figure 1 and figure 2 is an embodiment of a hose pump according to the invention for conveying a fluid guided in a hose 16, in a perspective view ( figure 1 , with inserted tube 16) or in a sectional view ( figure 2 , shown with a sectional plane centered through a lower guide level of the guide rollers). The hose pump is used, for example, to convey an injection liquid for a medical injection, in particular an intravenous injection, with the injection liquid being fed from a reservoir into a patient hose which is in particular connected intravenously to the patient. The peristaltic pump is arranged in a pump housing 14 to which a housing cover, not shown here for the sake of clarity, is pivoted by means of a fastening device 18 . A hold-down device is expediently formed on the housing cover.

The pump housing 14 contains a cassette receptacle 13 ( figure 2 ) for inserting a removable cartridge 15 ( figure 1 ). In the figure 1 Cassette 15, partially shown, comprises a cassette housing 15a in which a guide channel 15b is formed. The guide channel 15b serves to guide a fluid to be conveyed with the peristaltic pump. A loop-shaped or curved section of the tube 16 protrudes from the cassette housing 15a. On the upper side of the cassette housing 15a, which is not shown here, the cassette 15 is connected to a number of connecting hoses, which can be connected to storage containers for liquids (e.g. injection liquids). A connector 15c is arranged on the side of the cassette housing 15a to which, for example, a patient tube can be connected in order to connect it to the tube 16 .

The peristaltic pump comprises a carrier disk 1 which is coupled to a drive via a drive shaft 10 attached centrally to the carrier disk 1 . The drive is, for example, an electric motor. When the drive is running, the carrier disk 1 is set in rotation about an axis of rotation in the conveying direction (F) via the drive shaft 10, which is non-rotatably connected to the carrier disk 1. In the exemplary embodiment illustrated in the drawing, the conveying direction F (direction of rotation of the carrier disk in pump operation) runs clockwise.

The hose pump also includes a hose bed 2 with a hose inlet 2a and a hose outlet 2b, and a counter bearing 4. The counter bearing 4 is on the inner circumference of a circle segment, which is open in the region of the hose inlet 2a and the hose outlet 2b of the hose bed 2 for the introduction of a hose 16. The tube bed 2 serves to accommodate a tube section of a pump tube (the tube section is also referred to in general as tube 16 below), a fluid (for example an injection liquid for intravenous injection into the bloodstream of a patient) being guided in the tube. A tube 16 laid in the tube bed 2 rests on a guide surface formed by the surface of the carrier disc 1 . In the area of the hose outlet 2b of the hose bed 2, the counter bearing 4 runs out tangentially to the outside, as can be seen from the figures.

At the hose outlet 2b there is a threading-out device with an elevation 8 projecting over the surface of the carrier disk 1, as in FIG EP 2 924 288 A2 described.

A plurality of pinch rollers 3 are rotatably mounted about an axis perpendicular to the carrier disk 1 in the radially outer section (near its outer circumference) on the surface of the carrier disk 1 . The axes of the squeezing rollers 3 lie on a circular path (dashed line in Fig figure 2 ). In the exemplary embodiment of the peristaltic pump according to the invention shown here in the drawing, three such squeezing rollers 3a, 3b, 3c are provided and distributed evenly over the circumference of the carrier disk 1. When reference is made below to the identically designed squeezing rollers 3a, 3b, 3c, this is done with the reference numeral 3. The squeezing rollers 3 are at least essentially cylindrical with a smooth lateral surface and have a flat upper side 23 at the front.

A guide roller 5 is arranged on the carrier disc 1 between adjacent pinch rollers 3 . In the exemplary embodiment of the peristaltic pump according to the invention shown here in the drawing, three such guide rollers 5a, 5b, 5c are provided and distributed evenly over the circumference of the carrier disk 1 (or on the dashed circular path). When reference is made below to the at least essentially identically designed guide rollers 5a, 5b, 5c, this is done with reference number 5. The guide rollers 5 are rotatably mounted on the carrier disk 1, the axes of the guide rollers 5, like the axes of the pinch rollers 3, being parallel to the drive shaft 10 and also on the circular path (dashed circle in figure 2 ) lay.

The squeezing rollers 3 and the guide rollers 5 can either be freely rotatably mounted on the carrier disk 1 or also be coupled to the drive of the peristaltic pump via a clutch. If the squeezing rollers 3 and/or the guide rollers 5 are coupled to the drive via a clutch, they are rotated by the drive in the opposite direction to the carrier disk 1 when the drive is running.

The squeezing rollers 3a, 3b, 3c and the guide rollers 5a, 5b, 5c are arranged on the radially outer edge of the carrier disk 1 in such a way that the angular distance δ between each guide roller and the squeezing roller that follows a guide roller in the conveying direction is less than 60° and - as in the exemplary embodiment shown figures 1 and 2 - is in particular 45 °. Correspondingly, the angular distance Δ between a guide roller and the squeezing roller preceding this guide roller in the conveying direction is greater than 60° and is 75° in the exemplary embodiment shown. In the in the figures 1 and 2 In the exemplary embodiment shown, the angular distance δ between the guide roller 5a and the squeezing roller (3a) following this guide roller 5a in the conveying direction F is δ=45°. This preferred arrangement of the pinch and guide rollers is in EP 3 232 059 A2 described.

From the detail view of Figures 3 and 4 the structure of the guide rollers 5 can be seen. The guide rollers 5 essentially have a cylindrical basic shape and on their outer circumference (on the cylinder jacket) a guide groove 25 running in the circumferential direction. The guide grooves 25 of the guide rollers 5 form a first guide level 25 in which a hose 16 laid in the hose bed 2 is guided through the guide rollers 5 when the hose pump is in operation, with the carrier disk 1 being set in rotation by the drive when the pump is running and the hose 16 engaging in the guide grooves 25 of the guide rollers 5 and thereby being held on the guide surface of the hose bed 2.

Above the guide groove 25, each guide roller 5 has a guide cylinder 26, as shown in FIG figure 3 apparent. The guide cylinder 26 of each guide roller 5 faces away from the carrier disc 1 and the guide cylinder 26 of the guide rollers 5 form one upper, second management plane B, which is arranged offset to the first management plane A axially upwards (that is, pointing away from the carrier disc 1). The second guide level B is separated from the first guide level A by an annular flange 20 running around the outer circumference of each guide roller 5 . The underside of the annular flange 20 forms the upper section of the guide groove 25 for each guide roller 5 and the top of the annular flange 20 merges into a semi-groove 21 with an approximately quarter-circle cross section, which is part of the second guide level B. The height of the guide cylinders 26 of the guide rollers 5 is adapted to the diameter of the hose 16 to be inserted into the hose bed and corresponds at least to the hose diameter. The height of the guide cylinders 26 is preferably (slightly) greater than the hose diameter.

The second management level B, which is formed by the guide cylinders 26 of the guide rollers 5 and the annular flange 20, lies above the flat upper side 23 of the pinch rollers 3, as can be seen from the side view of FIG figure 4 evident. A cover 22 connecting and covering the guide rollers 5 is arranged on the upper side 24 of the cylinder formed by the end faces of the guide cylinders 26 (the cover 22 is shown in FIG figure 2 omitted). The cover 22 is star-shaped here and has a central opening and a number of convex indentations 27 .

In the embodiment of the peristaltic pump shown in the drawings, one of the guide rollers 5 (here the guide roller 5a) has the annular flange 20 between the guide groove 25 and the guide cylinder 26 arranged above it, in comparison to the annular flange 20 of the other guide rollers (here the guide rollers 5b and 5c) arranged axially offset upwards away from the carrier disk 1. This is over figure 4 by comparing the shape of the guide rollers 5a and 5c shown there. Compared to the other guide rollers (5b and 5c), this guide roller 5a with the annular flange 20 offset axially upwards has a slightly modified cross-sectional shape of the guide groove 25 with a slightly enlarged cross section in the upper section. The cross-sectional shape of the guide groove 25 of the guide roller 5a with the annular flange 20 offset axially upwards therefore deviates somewhat from the shape of a semicircular groove, as shown in FIG figure 4 evident.

For the operation of the peristaltic pump, the section of the pump hose 16 protruding from the cassette housing 15a is threaded into the hose bed 2, as described below with reference to FIG Figures 5 to 8 explained:

First, an operator inserts a cassette 15 into the receptacle 13 provided for it on the pump housing 14 . After inserting the cassette 15 into the receptacle 13 provided for this purpose, the operator manually places the section of the hose 16 protruding from the cassette housing 15a around the guide cylinders 26 of the guide rollers 5, as shown in FIG figure 5 shown. The hose 16 is then located in the second guide plane B defined by the guide cylinders 26 of the guide rollers 25. The length of the section of the hose 16 protruding from the cassette housing 15a is adapted to the geometry of the peristaltic pump in such a way that when the hose 16 is placed around the guide cylinders 26 of the guide rollers 5, the hose 16 is placed under a slight pretension and is thereby slightly stretched in its longitudinal direction.

To thread the hose 16 into the hose bed 2 , the area of the hose 16 which is located at the hose inlet 2a of the hose bed 2 is pressed down in the direction of the carrier disk 1 . This can be done manually by the operator using a finger, as in figure 6 implied. However, the hose 16 can also be pressed down in the area of the hose inlet 2a of the hose bed 2 in an automated manner by a mechanical hold-down device. The mechanical hold-down device can be, for example, a lever arranged movably on the pump housing 14 . However, the hold-down device can also be arranged on the inside of the cover of the pump housing 14, which is pivoted to the pump housing 14 by means of the fastening device 18 (for reasons of clarity, the housing cover is not shown in the drawings). The hold-down device is expediently arranged on the inside of the housing cover in such a way that when the housing cover is closed, the hold-down device automatically presses the hose 16 laid around the guide rollers 5 in the area of the hose inlet 2a of the hose bed 2 down to the carrier disk 1.

At the same time as the tube 16 is pressed down in the region of the tube inlet 2a of the tube bed 2, the carrier disk 1 is rotated in the conveying direction (clockwise in the exemplary embodiment shown). This rotation can be done either manually by the operator or automatically by the drive of the peristaltic pump, which is coupled to the carrier disk 1. To turn the carrier disk 1 manually, the operator can apply a torque to the carrier disk 1 with one hand via the cover 22 exercise The carrier disc 1 is rotated (either manually by the operator or automatically by the drive of the hose pump) in the conveying direction until the hose 16 engages in the guide groove 25 of a guide roller 5 (in figure 7 this is the guide groove 5c). By pressing down the tube 16 in the area of the tube inlet 2a of the tube bed 2, the tube 16 is brought into the lower, first guide level A in this area, in which the guide grooves 25 of the guide rollers 5 are located. When one of the guide rollers 5 runs past the hose inlet 2a in the conveying direction due to the rotation of the carrier disk 1 (here the guide groove 5c, as in figure 7 shown), the section of the hose 16 located in the lower, first guide plane A will therefore engage in the guide groove 25 of the relevant guide roller (here: the guide roller 5c). With further rotation of the carrier disk 1 in the conveying direction, the entire tube 16 is pulled over the entire circumference of the tube bed 2 due to the guidance in the guide groove 25 of this guide roller 5c downwards towards the carrier disk 1 from the upper guide level B to the lower, first guide level A. In the process, the tube 16 is stretched further slightly due to a slightly larger angle of wrap in the first guide plane A compared to the angle of wrap in the second guide plane B. Due to the pretensioning of the hose 16 that is already present, the hose is also pulled radially inwards, which is why the hose 16 has hardly any contact with the counter bearing 14 of the hose pump during the threading process. This minimizes friction of the hose 16 on the counter bearing 4 when the hose is threaded in, which is why any differences in the mechanical properties and in particular in relation to the sliding friction of the hose during the threading-in process have no effect. For this reason, with the hose pump according to the invention, different hoses, in particular hoses made of different materials and with different coefficients of friction, can always be threaded into the hose bed 2 with the same exact fit and reliably.

As soon as the carrier disk 1 has completed a complete rotation (i.e. by 360°) during the threading process, the hose 16 is completely in the lower, first guide level A, as in figure 8 shown, and is thereby fully inserted in the tube bed 2. The peristaltic pump is now ready for operation to deliver a fluid located in the hose 16 .

After the section of the hose 16 protruding from the cassette has been threaded into the hose bed 2 in the manner described above, the pump can be operated in its conveying direction F to convey the fluid located in the hose. For this purpose, the carrier disc 1 in the embodiment shown in the drawing is set in rotation by the drive in the conveying direction (here: clockwise), as a result of which the pinch rollers 3 intermittently press the hose against the counter bearing 4 while squeezing it, thereby transporting the fluid in the hose in the conveying direction. The guide rollers 5 ensure a secure and constant positioning of the section of the hose 16 in the hose bed 2, in that the hose engages in the guide grooves 25 of the guide rollers 5 and is guided thereby.

When the hose 16 has been correctly threaded into the hose bed 2, it is guided through the guide groove 25 of the guide rollers 5 and runs at a small distance and essentially parallel to the surface of the carrier disk 1 and between the outer circumference of the squeezing rollers 3 and the counter bearing 4. The (radial) distance between the outer circumference of the squeezing rollers 3 is selected to be smaller than the diameter of the hose 16, so that the hose between the outer circumference of the squeezing rollers 3 and the counter bearing 4 is below crushing of the flexible hose is pinched.

If, during the threading process, the section of hose 16 pressed down in the hose entry area 2a is not pulled by a guide roller 5 (in figure 7 the guide roller 5c) should be caught in its guide groove 25, the carrier disc 1 is rotated further in the conveying direction until the guide roller (in figure 7 the guide roller 5b) passes the hose inlet 2a. If necessary, this can be repeated until the tube 16 engages in a guide groove 25 of one of the guide rollers 5 .

As explained above, in comparison to the other guide rollers 5b, 5c, the guide roller 5a has an annular flange 20 that is offset upwards and, as a result, has an enlarged insertion cross section in the area of its guide groove 25. The enlarged insertion cross section of the guide roller 5a can ensure that the section of the hose 16 pressed down in the area of the hose inlet 2a is always caught by the guide groove 25 of this guide roller 5a and thereby by the upper, second Management level B is pulled into the lower, first management level A. At the latest when the guide roller 5a with the annular flange 20 offset upwards enters the area of the hose inlet 2a, the hose is gripped by the guide groove 25 of this guide roller 5c and, with further rotation of the carrier disk, is pulled down into the lower, first guide level A.

A corresponding device is expediently provided in the peristaltic pump to monitor the threading process. This device for monitoring the threading process can, for example, comprise a device for detecting the torque acting on the carrier disk 1 . As soon as the hose has been brought completely into the lower, first guide level A during the threading process, the rotational resistance of the carrier disk 1 increases, which is why the drive of the hose pump has to apply a higher torque for further rotation of the carrier disk 1 (at the same rotational speed). By detecting the torque acting on the carrier disk 1, it is therefore possible to draw conclusions about the status of the threading process. As soon as the torque acting on the carrier disk 1 exceeds a predetermined torque threshold value, a signal generator emits a signal which indicates to the operator that the tube 16 has been correctly inserted into the tube bed 2 .

In the event that a threading process could not be completed properly, despite multiple attempts, it can be provided that the signal generator emits a second signal after a specified period of time has elapsed if the specified torque threshold value has not been reached or exceeded within this period of time. When the signal transmitter issues the second signal, the operator receives the information that the threading process was unsuccessful. In this case, the operator can insert another cassette 15 into the receptacle 13 provided on the peristaltic pump and start a new threading process.

If the hose pump is blocked during a threading process, for example due to the hose 16 becoming tangled, this is also detected by the device for monitoring the threading process and the signal transmitter can output a corresponding signal. In the event of a pump blockage, the threading process is blocked and the operator is prompted to insert a new cassette 15 .

The signals can be output in the form of an acoustic signal or in the form of an indication on a display, for example.

After the end of the operation of the hose pump, the hose 16 can be unthreaded from the hose bed 2 via an automatic unthreading routine. For this purpose, the carrier disc 1 is rotated by the drive of the peristaltic pump in the opposite direction to the conveying direction (that is to say counterclockwise in the exemplary embodiment shown). To unthread the hose, the hose outlet 2b of the hose bed 2 is arranged and removed figure 9 visible survey 8 used. The elevation 8 protrudes above the surface of the carrier disc 1 and lifts the hose 16 slightly from the surface of the carrier disc 1 in the area of the hose outlet 2a. When the carrier disc 1 rotates against the conveying direction (counterclockwise), the guide roller 5c, which moves past the hose outlet 2a as a result of the rotation of the carrier disc 1, grips the hose 16 with its annular flange 20 and thereby lifts it from the lower, first guide level A to the upper, second guide level B, as shown in FIG figure 9 shown. Upon further rotation of the carrier disc 1 counter to the conveying direction, the hose 16 is lifted over the entire circumference of the hose bed 2 from the lower, first guidance level A to the upper, second guidance plane B until, after a complete rotation of the carrier disc 1 (by 360°) counter to the conveying direction, the hose 16 is located completely and over the entire circumference of the hose bed 2 in the upper, second guidance plane B (according to the figure 5 shown position). In this position, the hose 16 can be pulled upwards by the operator from the guide rollers 5 and removed together with the cassette 15 from the hose pump.

The device for monitoring the threading process is preferably coupled to a control device of the peristaltic pump. This enables the execution of programmed threading-in and threading-out routines by the control device, with the device for monitoring the threading-in process detecting the status of the threading-in process and, if necessary, restarting the threading-in process if the tube could not be successfully threaded in, or terminating the threading-in process if the tube could be successfully threaded in. The same applies to the unthreading process.

The invention is not limited to the embodiment illustrated here in the drawing. For example, the number of pinch rollers 3 and guide rollers 5 can be selected differently. However, it is expedient to provide the same number of guide rollers and squeezing rollers, so that each squeezing roller 3 is assigned a guide roller 5 . Four squeezing rollers 3 and four guide rollers 5, for example, can be provided, which are arranged in alternating sequence on the carrier disk 1 such that their axes lie on a circular path running concentrically around the axis of rotation A of the carrier disk 1. The angular distances between the squeezing rollers and between the guide rollers are equidistant. With four guide and pinch rollers, this distance between the guide and pinch rollers is 90°. The angular distance between the squeezing rollers 3 and the guide rollers 5 can expediently be different, as described above, or even equidistant.

Instead of the cover 22 (or in addition to it), a central cylinder that protrudes above the surface of the carrier disk 1 can be arranged in the center of the carrier disk 1 coaxially to its axis of rotation. There is (as little as possible) a distance between the outer circumference of the central cylinder and the outer circumference of the pinch rollers and the guide rollers. The central cylinder can be designed as a hollow cylinder or also as a solid cylinder and is expediently connected to the carrier disk 1 in a rotationally fixed manner. When threading in the hose, the central cylinder prevents it from coming to rest on the side of the guide rollers 5 pointing radially inwards and therefore cannot be properly threaded into the hose bed 2 between the outer circumference of the pinch rollers 3 and the counter bearing 4 . For this purpose, the radial distance between the lateral surface of the cylinder and the outer circumference of the guide rollers should be smaller than the diameter of the hose to be inserted into the hose bed. The height of the central cylinder (in the axial direction) is expediently adapted to the height of the guide rollers and has at least the same height as the guide rollers.

Claims (13)

1. Peristaltic pump for conveying a fluid guided in a hose, comprising a hose bed (2) having an abutment (4) for receiving the hose, a carrier disc (1) rotatable relative to the abutment (2), a plurality of squeeze rollers (3) arranged on the carrier disc (1) in the circumferential direction, and a plurality of guide rollers (5) arranged on the carrier disc (1) in the circumferential direction and having a guide groove (25) running around their outer circumference in the circumferential direction, which forms a first guide plane (A) facing the carrier disc (1), characterized in that each guide roller (5) has, above the guide groove (25), a guide cylinder (26) for guiding the hose during threading into the hose bed (2) and/or during threading out of the hose bed (2), as well as an annular flange (20) running around the outer circumference of the guide roller (5) between the guide groove (25) and the guide cylinder (26), wherein the guide cylinder (26) together with the annular flange (20) forms a second guide plane (B) arranged axially offset to the first guide plane (A).
2. Peristaltic pump according to claim 1, characterised in that in at least one guide roller (5a) of the plurality of guide rollers (5) the annular flange (20) between the guide groove (25) and the guide cylinder (26) is offset away from the carrier disc (1) in comparison with the annular flange (20) of the remaining guide rollers (5b, 5c).
3. Peristaltic pump according to claim 1, characterised in that the first guide plane (A) and the second guide plane (B) are separated from each other by an annular flange (20) running around the outer circumference of each guide roller (5), wherein the annular flange (20) can be inclined parallel to the guide groove (25) or in a helical manner in the conveying direction (F) in the direction of the carrier disc (1).
4. Peristaltic pump according to one of the claims 1 to 3 , characterised in that the second guide plane (B) comprises a half groove (21) running around the outer circumference of the guide roller (5).
5. Peristaltic pump according to one of the preceding claims, characterised in that the height of the guide cylinder (26) at each guide roller (5) is at least as great as the diameter of the hose.
6. Peristaltic pump according to one of the preceding claims, characterised in that the squeeze rollers (3) are formed at least substantially cylindrically and with a flat upper side (23), the guide cylinders (26) of the guide rollers (5) lying above the upper side (23) of the squeeze rollers (3) in the axial direction.
7. Peristaltic pump according to one of the preceding claims, characterised in that each guide roller (5) has an upper side (24) formed by the end face of the guide cylinder (25) and in that a cover (22) connecting the guide rollers (5) is arranged on the upper side (24) of each guide roller (5).
8. Peristaltic pump according to claim 7, characterised in that the cover (22) is cross-shaped or star-shaped and preferably has indentations (27) in the region between two adjacent guide rollers (5), wherein the indentations (27) can be in particular convex, rectangular or part-circular.
9. Peristaltic pump according to one of the preceding claims, characterised in that the guide groove (25) of at least one guide roller (5) has at least substantially a part-circular, in particular a semicircular cross-section and/or in that the second guide plane (B) of each guide roller (5) is formed by a half-groove (21) which has in particular a quarter-circular cross-section.
10. Peristaltic pump according to one of the preceding claims, characterised in that a single hose is inserted into the hose bed (2) and the squeezing rollers (3) press the hose against the counter bearing (4) while the carrier disc (1) rotates, in order to transport a fluid in the hose in the conveying direction.
11. Method for threading a hose into a hose bed (2) of a peristaltic pump according to one of the preceding claims, characterized in that, for threading the hose into the hose bed (2), the hose is first inserted into the second guide plane (B) of the guide rollers (5) facing away from the carrier disc (1), the carrier disc (1) is then rotated in the conveying direction and thereby the hose is brought from the second guide plane (B) in the axial direction towards the carrier disc (1) into the first guide plane (A).
12. Method according to claim 11, wherein a pre-tension is generated on the hose when the hose is inserted into the second guide plane (B) of the guide rollers (5).
13. Method according to claim 11 or 12, characterised in that the torque acting on the carrier disc (1) is detected at least during threading of the hose and, if a torque threshold value is exceeded, a first signal and, additionally or alternatively, a second signal are output if the torque threshold value has not been reached or exceeded after a predetermined period of time has elapsed.

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