Abstract:
A roller pump includes a stator with a pump bed formed therein, and a rotor for acting on a hose inserted into the pump bed in arcuate form. The ends of the hose are guided out of the pump bed in a crossed configuration.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a nationalization of PCT/EP05/005191 filed May 12, 2005 and published in German. 
   BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The invention relates to a roller pump having a stator with a pump bed formed therein and a rotor for acting on a hose inserted into the pump bed in arcuate form. 
   2. Description of The Prior Art 
   Roller pumps of this type are known, for example, from U.S. 4,545,744. They consist of a stator with a pump bed formed therein and a rotor for acting on a hose insertable into the pump bed in arcuate form. it is already proposed here to connect the pump hose segment, which is inserted into the pump bed of the roller pump, via a connector to an incoming and an outgoing liquid hose. This connector prevents a slipping of the pump hose segment during the pumping process. At the same time, it is avoided on the basis of an asymmetry in the connector that the pre-assembled hose segment is inserted in a laterally transposed manner. The pump hose segment is preshaped in an arcuate manner by the connector. The incoming and outgoing liquid hose is, in contrast, guided out of the connector in a parallel manner. This has the result that the incoming and outgoing liquid hose in each case requires a great deal of room outside the pump bed in order not to be kinked on a direction-changing hose guidance. A simple bending of the hoses outside the pump bed is not possible since otherwise the liquid flow would be interrupted. 
   SUMMARY OF THE INVENTION 
   It is the object of the invention to further develop the generic roller pump such that liquid-conducting hoses can be used in a particularly space-saving manner. 
   This object is solved in accordance with the invention by the combination of the features described herein. Accordingly, a roller pump consists of a stator having a pump bed formed therein and a rotor for acting on a hose inserted into the pump bed in arcuate form, with the ends of the hose guided out of the pump bed crossing directly after exiting the pump bed. A pump segment thus results in the form of a Greek alpha. The hoses can be guided further in a space-saving manner below or next to the roller pump due to this shape without there being any risk of kinking. 
   Further particularly preferred embodiment variants of the invention are as described herein. 
   The hose can advantageously be fixable in the roller pump by a connector. The hose inserted into the roller pump can be guidable through the connector and thus be made as a hose in one piece. Alternatively, however, a separate hose piece insertable into the pump bed and the infeeding and outgoing hose piece can also be connected in the connector. 
   The connector can advantageously be made as an adapter, with the adapter being insertable in the roller pump in corresponding reception recesses on the basis of its shape. Due to this respective shape matching, a coding can be realized which can also be supported by a corresponding coloring. The reception recesses of the adapter engage laterally into two clip receivers, preferably of different shape. The clipable adapter is matched to the corresponding shape of the clips. 
   In accordance with another advantageous aspect of the invention, a device, preferably a pimple, is arranged at the adapter and cooperates with a sensor integrated in the roller pump or in the housing forming the roller pump. The sensor confirms the functionally correct insertion of the adapter at the corresponding point. 
   The adapter particularly advantageously consists of a soft plastic, preferably soft PVC. 
   The advantages of the hose guidance in accordance with the invention result in a very particularly advantageous manner when the connector is arranged laterally at the pump bed with a horizontal alignment of the rotor axis. An optimum bleeding of the hose segment can be achieved by this arrangement in cooperation with a corresponding direction of rotation of the rotor. It is namely ensured that air which is in the inlet region rises upwardly due to the lifting force. The corresponding pressing rollers of the rotor engage into the hose segment disposed in the pump bed still during the rising and guarantee a compulsory conveying of the corresponding air bubbles. It is similar at the outlet of the hose segment. When the pressing rollers release the hose segment again, the air taken along is already in the rising region of the hose segment. There is thereby no force driving the air back into the pump. These advantages cannot be achieved either with a U-shaped arrangement or with an Ω-shaped arrangement of the hose segment in the pump bed such as were known in the prior art. 
   To achieve the optimum bleeding, the roller pump has a control unit which sets the corresponding rotary direction of the rotor in dependence on the lateral alignment of the connector. The rotor is thus rotated counterclockwise when the hoses cross on the right hand side and clockwise when the hoses cross on the left hand side. 
   The hose insertable into the roller pump can also be connected to a connector which is made as an integrated cassette. Finally, the invention also relates to a hose set having a connector such as was previously described as well as a hose to be inserted into the pump bed and connected to the connector. 
   The invention also relates to a connector which can be inserted into a roller pump in accordance with the invention. 

   
     BREIF DESCREPTION OF DRAWINGS 
     Further features, details and advantages of the invention result from embodiments shown in the drawing. 
     There are shown: 
       FIG. 1  a schematic view of a roller pump in accordance with a first embodiment of the invention; 
       FIG. 2 : a roller pump housing in different views; 
       FIG. 3 : an adapter piece in different views and sections which can be inserted into the roller pump in accordance with  FIG. 2 ; and 
       FIG. 4 : a schematic representation of the hose piece which can be inserted into a roller pump not shown in any more detail here and which is connected to a cassette. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
   In  FIG. 1 , a roller pump  10  is shown with a pump bed  22  and an inserted hose  12  which is connected to a connector  14  made as an adapter. An infeeding hose  16  and an outgoing hose  18  are also shown as a hose set at the connector  14 . The direction of the arrow indicates the direction of flow of the liquid inside the hose. The ends of the hose guided out of the pump bed cross in the connector  14  in this manner. 
   The flexible hose  12  is compressed continuously in the direction of the arrow A by a rotor  11  of the roller pump  10  with corresponding rollers  13  so that the corresponding pump effect for the liquid results. A space-saving infeed and outward guidance of the hose  12  or of the hose parts  16  and  18  is possible due to the crossing guidance of the hose  12  resulting from the representation in accordance with  FIG. 1  or due to the hose guidance formed by the hose parts  12 , 16  and  18  and the connector  14  directly next to the opening  24  of the pump bed  22 . The hose shape shown in  FIG. 1  can be described as an alpha shape in which the ends of the hose  12  guided out of the pump  22  are guided out tangentially and in a crossing manner from the pump bed  22 . The hose parts  16  and  18  can also be guided out of the pump directly laterally (not shown). 
   In  FIG. 2 , different views of a roller pump housing  20  made as an injection-molded part are shown. Only the stator of the roller pump  10  is shown here.  FIG. 2   a ) shows a plan view from above;  FIG. 2   b ) a side view;  FIG. 2   c ) a view from the front; and  FIG. 2   d ) a perspective view from above, whereas  FIG. 2   e ) shows a perspective view from below. A pump bed  22  is formed in the roller pump housing  20  and the arcuately shaped hose  12  can be inserted into it in a manner not shown in any more detail here. The pump bed  22  has an opening  24  toward one side. The lateral end regions of the opening  24  are formed by clip receivers  26  and  28  of different shape. As can be seen from  FIG. 2   d ), the clip receivers  26  and  28  are separable from the roller pump housing  20 . They are fastenable to the housing  20  with corresponding fastening pins  30  and are replaceable. The respective rotor with the corresponding rollers for acting on the hose  12  insertable into the pump bed in arcuate shape is not shown in any more detail here. 
     FIG. 3   a ) shows a plan view of an adapter piece  32  which can close the opening  24  of the housing  20  in accordance with  FIG. 2 . In  FIG. 3   b ), a corresponding sectional representation in accordance with the line of intersection IIIb-IIIB through  FIG. 3   a ) is shown. In  FIG. 3   c ), a corresponding sectional representation in accordance with the line of intersection IIIc-IIIc in  FIG. 3   a ) is shown. It can first be seen from  FIG. 3  that the adapter  32  has corresponding connection regions  36  or  38  for the hoses  16  and  18  and connection regions  34  for the hose  12 . When the corresponding hose pieces are connected, they can be clipped into the housing  20  together with the adapter  32 , with them being fixed by the corresponding clip receivers  26  and  28 . The corresponding recesses  40  and  42  in the adapter  32  are each matched to the shapes of the clip receivers  26  and  28 . A specific association of the hose  12  provided with the adapter  32  to a corresponding roller pump  10  can take place here by a corresponding association of the shape of the adapter  32  in the clip receivers  26  and  28 . To ensure a simple recognizability for the user here, the adapters  32  can be of different color to allow them to be associated more easily with the respective roller pump  10 . A pimple (not shown) is arranged at the lower side of the adapter  14  and cooperates with a sensor integrated in the roller pump to make the proper assembly of the connector or of the correspondingly pre-assembled hose set checkable by the control unit of the roller pump. Such a hose set can include a hose connected to the adapter and to be inserted into the pump bed as well as corresponding hoses leading away from the pump. 
     FIG. 4  shows a further embodiment of a roller pump  10  in accordance with the invention. Here, only the hose  12  is shown without a roller pump housing. The direction of rotation of the rotor  11  is indicated by the direction of the arrow A. An integrated cassette  50  in which different functional units can be realized is provided as the connector piece here. A pressure measuring device  52  is integrated here by way of example. The ends of the hose guided out of the pump bed also cross in the connector directly next to the rotor region of the pump, i.e. of the opening of the pump bed, in this embodiment. 
   In the liquid guidance shown here, an optimum bleeding of the hose segment  12  likewise results. Air which lies in the inlet region of the hose  12  rises upwardly due to the lifting force and is compulsorily guided within the rise by the pressure rollers of the rotor along the hose  12 . To the extent they arrive at the end region of the hose  12  (viewed in the direction of the arrow A), the air taken along is likewise located in the rising region of the hose  12  so that they rise further and are carried out through the hose  18 . This advantageous bleeding results when the crossing part of the hose is arranged on the right hand side and the rotor  11  simultaneously turns counterclockwise. Alternatively, the advantageous bleeding results for the case that the crossing part of the hose is on the left hand side when the rotor turns clockwise. 
   Generally, the structure in accordance with the invention of the roller pump also permits a more flexible and space-saving design of the fluid guidance with an integrated cassette. 
   As previously stated, the adapter  32  can be clipped into the housing  20 . As in particular results from  FIG. 2   b ), the clip receivers  26  and  28  have nose-like projections  51 ,  53  at the upper end. When the adapter  32  is inserted, it moves beneath these projections, which represents the actual clipping function. The right hand projection  51  forming one side of the clip receiver protrudes further over the margin of the recess of the inserted adapter than the projection  53  on the left hand side (e.g. approximately 1 mm versus some 10 ths mm). On the left hand side, the shape  42  of the adapter piece (cf.  FIG. 3 ) is roundish (approximated to an arc of a circle here), whereas it is angled at the right hand side (reference symbol  40  in  FIG. 3 ). This special geometric coding results in the advantage that the adapter  32  can be released more easily on the round side than on the angled side on the removal from the housing  20 . This is now ensured, on the one hand, by the different overlap of the projections  51 ,  53  (on the part of the housing  20 ) and, on the other hand, via the better resilience of the round side  42  over the angled side  40  (on the part of the adapter). 
   The ejection of the adapter takes place via a pin  54  (cf.  FIG. 2 ). The pin is made close to the round clip receiver  28  such that, on the corresponding actuation of the pin  54 , the adapter  34  is initially separated from the housing on the round contact side. The corresponding pin  54  can be moved out in a controlled manner not shown in any more detail here by the pump-side housing so that the round side  42  of the adapter  32  snaps out of the clip receiver. 
   A type of key/lock principle results by the design of the round recess  42 , on the one hand, in connection with the round projection  53  of the housing and the angled recess  40  in connection with the angled projection  51  of the housing, for which protection is claimed separately. 
   The tilt movement generated by the arrangement of the pin  54  on the ejection of the adapter has yet another advantage. The roller pump  10  is equipped with two radial pins such as is also described in U.S. Pat. No. 4,545,744. The two pins are attached on mutually oppositely disposed sides. When the left hand side of the adapter  32  is raised and the right hand side of the adapter  32  is not raised, the lower pin can move easily beneath the hose in the clockwise direction in order to raise this, whereas the upper pin can first extend without problem over the still inserted hose. With a simultaneous raising of both pins, a pin can catch in the pump hose system. This is prevented by the tilt movement on the ejection of the adapter  32 . 
   The adapter  32  is made such that it permits a cant-free connection between the pump hose segment  12  and the outer segments  16 ,  18  which, as can be seen, for example in  FIG. 1 , have different inner diameters. This can also be recognized in  FIGS. 3   b  and  3   c  in which the openings  34  have a first width and the openings  36  and  38  have a second, smaller width. A transition region directly adjoins this opening. The openings of the transition region correspond to the inner diameters of the hose segments to be inserted. The transition region is characterized in accordance with the invention by a constant transition of the inner diameter to achieve a homogeneous flow which is as blood-compatible as possible. 
   Furthermore, the crossing region of the two hose segments  16  and  18  is already disposed in a region in which the inner diameters of the two lines are substantially reduced. In accordance with the invention, this permits an alignment of the total pump loop which is as good and smooth as possible so that there is no excessive wear due to the hose guidance pins. 
   The pin  54  in accordance with  FIG. 2   a ) can simultaneously serve as a sensor for a pimple provided at the adapter  32 . The pin  54  is here displaced vertically in a manner not shown in any more detail by pressing in the pimple, which can be recognized by a light barrier likewise not shown in any more detail here. 
   It can be recognized in the section IIId-IIId, as it is shown in  FIG. 3   d , that the spacing at the round recess  42  and at the angled recess  40  of the adapter  32  reduces from top to bottom. This permits a better mold removability of the adapter in the manufacture. 
   A second projection, not shown in the Figures, which acts as an abutment for the tilting adapter  32  can be provided at the left hand clip receiver  28 . 
   The geometrical associations not shown in this embodiment with respect to the left hand side and the right hand side—namely those of the shape of the clip receivers, those of the projections  51 ,  53 , and also the arrangement of the pin  54 , as well as of the second projection—can be swapped as required. 
   It can be seen from  FIG. 1  that the lines continuing the hose segments  16  and  18  cross at right angles in the adapter. 
   The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims.