Patent Publication Number: US-2023160380-A1

Title: Peristaltic pump

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a peristaltic pump as well as a pump system comprising the peristaltic pump and a method for pumping a fluid by the pump system. 
     TECHNICAL BACKGROUND 
     Peristaltic pumps are commonly known in the prior art. They are used for an accurate delivery of small amounts of liquids. Therefore, the peristaltic pump comprises a rotary body with a plurality of squeeze sections (typically rollers or wipers) arranged circularly distributed and moveable about a central rotation axis. A tube is partially wound around this rotary body so that some of the squeeze sections are in engagement with the so arranged flexible tube to squeeze corresponding sections of the tube. During rotational movement of the rotary body, the squeeze sections move/roll along the part of the flexible tube wound about the rotary body to thus deliver a correspondingly small amount of liquid between the squeezed sections and further downstream the tube after the squeeze sections again disengage from the flexible tube. 
     There is always one of the squeeze sections in engagement with the flexible tube to deliver the corresponding amount of liquid via the peristaltic pump. Hence, for cleaning purposes of the peristaltic pump and particularly the flexible tube or in case of an occlusion in the flexible tube, the flexible tube needs to be demounted from the peristaltic pump and either be replaced or cleaned separately, which requires a quite long stop of the peristaltic pump and adequate efforts by a trained person. Also, demounting of the flexible tube always bears the risk of contamination of an inside of the tube and thus the liquid to be delivered therein. 
     SUMMARY OF THE INVENTION 
     It is thus an object of the present invention to provide a peristaltic pump, which allows for an easy cleaning of the same preferably without demounting of any parts. 
     According to a first aspect, the present invention is thus directed to a peristaltic pump comprising a rotary body with a plurality of squeeze sections or elements (preferably comprising rollers, shoes, wipers, or lobes) arranged circularly distributed and moveable about a rotational axis. The peristaltic pump further comprises a tube carrier for carrying a flexible tube along an arcuate engagement section arcuately surrounding the rotary body. The peristaltic pump further comprises an actuator for selectively moving the tube carrier relative to the rotary body between a pump position in which a flexible tube carried by the tube carrier be—preferably irrespective of the rotational position of the rotary body about the rotational axis—positioned in engagement between the engagement section and at least one, preferably at least two of the squeeze sections, respectively, to allow for a pumping action when moving the rotary body about the rotation axis, and a release position in which the flexible tube carried by the tube carrier be disengaged/released from the plurality of squeeze sections to allow for free flow through the flexible tube. 
     In the present invention, the term “free flow” means that the flexible tube is in a condition to allow for (unpressurized or pressurized) fluid/liquid to flow through the flexible tube without rotational movement of the rotary body/squeeze sections; i.e. the latter being sufficiently released from the flexible tube. Preferably, the flexible tube is in a less squeezed or even unsqueezed condition compared to the pumping condition (i.e. pump position) in which the flexible tube is correspondingly squeezed between the engagement section and the respective squeeze section(s) for allowing a pumping action by rotation of the rotary body/squeeze sections. 
     Due to the integrated release function by a corresponding actuator, the peristaltic pump can be easily brought by only a dedicated or minor movement from a commonly known pump position to a position in which the flexible tube is released from the squeeze sections so that the tube is open for free flow. In this position, a cleaning fluid or liquid can be delivered through the peristaltic pump to thus clean, sanitize or release the pump from any occlusions inside the flexible tube. Therefore, the peristaltic pump can be integrated in a pump system (described in more detail herein below) in which the inlet of the peristaltic pump is connected to both a product supply as well as a sanitizing liquid supply (which can be identical, e.g., in case of (hot) water to be delivered). The former (i.e. product supply) can, for instance, be a beverage ingredient or product or a medical product to be delivered via the rotation of the peristaltic pump. The latter (i.e. sanitizing liquid supply) can be, for instance, a water supply which preferably comprises a heater to heat up the water which allows for an effective sanitizing effect when delivering the hot water through the peristaltic pump in the release position. The sanitizing liquid may also be a chemically based sanitizing liquid. 
     The beverage ingredient or product may be carried in a container (e.g. a bag-in-box or a tetra based container, etc.), which can be selectively connected to an upstream end of the flexible tube. The beverage ingredient or product can be a liquid beverage product base as well as any type of additive. As non-exhaustive examples, the liquid beverage product base can be water, soda, lemonade, soup, and so on. The term “additive” mainly relates to a liquid component, or to a liquid component comprising small solid particles. However, the product supply can also be used for dissolving a solid, e.g. powdered, beverage ingredient as an additive carried in a container for delivering the so dissolved beverage ingredient by action of the peristaltic pump. Additive may preferably be understood as designating a liquid in an amount up to 5%, preferably 0.05% to 1%, preferably 0.1% to 0.5% by volume, of the main liquid material in a final beverage product. As non-exhaustive examples, additive can be a flavour or aroma (for example orange, peach, lemon, etc.) like an edible flavouring concentrate, a tea or coffee extract, a fruit juice, a minerals mother solution, etc. The additive can be a mineral liquid concentrate, or a so-called “functional” concentrate or enhancer such as an additive comprising a vitamin, caffeine or another coffee extract. The expression “functional concentrate” refers to a product that has an effect on the consumer, such as a product that is probiotic, prophylactic, etc. 
     The peristaltic pump can be integrated in a partially or full automatic pump system (e.g. a beverage preparation device) so that, for instance, cleaning and sanitizing cycles can be performed between pumping processes automatically (e.g. at defined intervals, after completion of each or a defined number of pumping or beverage production actions or at defined times of the day, e.g. by night) and/or on demand. 
     The actuator is preferably functionally connected to the tube carrier to allow for the movement of the tube carrier relative to the rotary body, preferably by a lifting cylinder and/or a gear drive. The functional connection is preferably of a physical nature. However, the actuator can also be functionally connected to the tube carrier, e.g. by a pneumatic function, wherein the corresponding pneumatic actuator features are then of course provided between the actuator and the tube carrier. Also, a magnetic drive or any other type of actuator is possible. Hence, the actuator may comprise an electric motor, a magnetic drive, a pneumatic actuator and/or hydraulic actuator. Of course, any other type of actuators suitable for the given function are possible to be used as well. The mentioned actuators are simple in structure and can thus be easily provided. 
     The movement of the tube carrier relative to the rotary body is preferably a rotational movement and/or a translational movement. The movement preferably depends on the given structure and layout of the peristaltic pump. Also, the movement depends on the actuator used for performing the movement of the tube carrier as well as the given transfer of corresponding movement directions. 
     The tube carrier and the plurality of squeeze sections are preferably configured such that, in the pump position, there are always at least two squeeze sections in functional position with respect to the arcuate engagement section to allow for the engagement of the flexible tube  5  there between. Hence, a secure and reliable pump function can always be ensured. 
     Preferably, in the pump position, the arcuate engagement section is coaxially positioned with respect to the rotation axis. Hence, the relative position of the squeeze sections and the arcuate engagement section can be clearly defined thus insuring the squeeze sections getting into sufficient engagement with the flexible tube to squeeze the latter for allowing the pump function of the peristaltic pump. 
     Preferably, in the release position, the arcuate engagement section is radially and/or axially offset from the squeeze sections with respect to the rotation axis compared to their relative position in the pump position. Hence, a secure release of the flexible tube from the engagement between the squeeze sections and the engagement section can be ensured. 
     The squeeze sections are preferably (each) axially biased away from the rotation axis. Hence, an engagement of the flexible tube between the respective squeeze section and the engagement section can be ensured irrespective of the dimensions and wall thickness or even variations of these factors of a flexible tube. 
     The tube carrier can be biased towards the release position. Hence, secure disengagement of the flexible tube via the tube carrier can be facilitated. The tube carrier may preferably comprise a lock element for locking the tube carrier in the pump position, e.g. in connection with a corresponding lock element on another part of the peristaltic pump, like a housing thereof. Hence, the flexible tube be kept in secure engagement with the squeeze sections can be ensured. 
     According to another aspect, the present invention is further directed to a pump system comprising a peristaltic pump according to the present invention, a flexible tube be functionally carried by the tube carrier, a product supply be fluidly connected to an upstream end of the flexible tube, and a product discharge section be fluidly connected to a downstream end of the flexible tube. 
     The peristaltic pump can thus be integrated in a corresponding pump system, like a beverage preparation device, in which the described easy cleaning and sanitization function can then be used; thus reducing the risk of viral or bacterial contamination and in turn severely reducing the risk of microbiological growth. Furthermore, as the cleaning/sanitization does not require a demounting of the flexible tube, maintenance time can be minimized. 
     The product supply may comprise a product container, preferably a beverage ingredient container and/or a sanitizing liquid container. Hence, a corresponding product and/or sanitizing liquid can be easily provided and the liquid carried therein be easily delivered by action of the peristaltic pump. Alternatively or additionally, the product supply may comprise a liquid supply, preferably a water supply and more preferred a hot water supply. The liquid supply can be a liquid storage to keep a desired amount of liquid and/or a liquid (e.g. water) connection for attaching an external water source like a water conduit for endless liquid delivery. For heating the liquid to provide a hot liquid (i.e. above ambient), the liquid supply may comprise a heater or boiler or any other type of heating element. A water or sanitizing liquid supply may be provided in line with and upstream a beverage ingredient supply so that the water or sanitizing liquid may be used along the whole delivery path for cleaning/sanitizing the same. Also, the water can then be used for supporting delivery of the beverage ingredient, e.g. carried in a container. 
     The pump system may further comprise an air supply being fluidly connected to the upstream end of the flexible tube. Hence, the delivery path and particularly the flexible tube can be evacuated when the tube carrier is in the release position; i.e. preferably after cleaning/sanitization of the peristaltic pump. Hence, residues of beverage ingredients or sanitizing liquid can be securely avoided. The air supply may deliver any type of gas, preferably air. The air supply may also comprise a heater for providing a heated gas or air to accelerate an evacuation and cleaning of the peristaltic pump, i.e. the flexible tube, and preferably the overall delivery path. The air supply may comprise a pump or compressor for delivery of the gas through the pump system (i.e. the delivery path). 
     The product discharge section can comprise a discharge opening, like a discharge nozzle, and may also comprise a mixing chamber, e.g., for mixing a final beverage product from a number of beverage ingredients—at least some of which be delivered to the mixing chamber by a peristaltic pump according to the present invention—before being dispensed. 
     According to another aspect, the present invention is directed to a method for pumping a fluid by (use of) a pump system according to the present invention, the method comprising the steps of (after having provided the pump system):
         for product delivery, positioning the tube carrier in the pump position, and pumping a liquid product from the product supply by pumping action of the peristaltic pump by rotational movement of the rotary body about the rotation axis towards the product discharge section, and   for cleaning and/or sanitization, moving the tube carrier in the release position, and delivering, preferably pumping, a fluid from the product supply, preferably the sanitizing liquid container and/or the liquid or water supply, through the peristaltic pump towards the product discharge section.       

     The method according to the present invention allows for an easy switching between a product delivery mode and a cleaning/sanitization mode thus minimizing a maintenance time while severely reducing the risk of a viral or bacterial contamination. 
     In the cleaning and/or sanitization step, after the fluid has been pumped through the pump system, evacuating and/or drying the pump system by pumping gas (e.g. air), preferably hot air, from the air supply via the peristaltic pump towards the product discharge section. Hence, evacuation of the fluidic or delivery path of the system can be accelerated and thus maintenance time even be further reduced. Also, residues of beverage products or sanitizing liquids within the system can be eliminated. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Further features, details and advantages of the present application will now be described with respect to the drawings of the enclosed Figures. 
         FIG.  1    shows a perspective view of a peristaltic pump according to an embodiment of the present invention; (A) in a pump position, and (B) in a release position, 
         FIG.  2    shows a cross-sectional side view of the peristaltic pump according to  FIG.  1   ; (A) in the pump position, and (B) in the release position, 
         FIG.  3    shows a cross-sectional top view of the peristaltic pump; (A) in the pump position and along lines A-A of  FIG.  2 A , and (B) in the release position along lines B-B of  FIG.  2 B , 
         FIG.  4    shows a schematic detail of the actuator of the peristaltic pump according to  FIG.  1   ; (A) in the pump position, and (B) in the release position, and 
         FIG.  5    shows a schematic view of a pump system with a peristaltic pump according to  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The FIGURES show a peristaltic pump  1  according to the present invention. The addition (A) to the FIGURES refers to the peristaltic pump  1  in the pump position, while the addition (B) refers to the peristaltic pump  1  in the release position. 
     The peristaltic pump  1  comprises a rotary body  2  with a plurality of squeeze sections or elements  3  arranged circularly distributed and moveable about a rotation axis A. Here, the rotary body  2  carries a total of eight squeeze sections  3 , while the number of squeeze sections  3  is not limited by the present invention. Preferably, the squeeze sections  3  are evenly distributed about the rotation axis A. In the shown embodiment, the squeeze section or element  3  comprises rollers. However, the squeeze sections  3  may also comprise shoes, wipers, lobes and the like. In the shown embodiment, the rotary body  2  is attached to a base  13  or housing  14  of the peristaltic pump  1 . 
     The peristaltic pump  1  further comprises a tube carrier  4  for carrying a flexible tube  5  along an arcuate engagement section  6  arcuately surrounding the rotary body  2 ; preferably about an angle of between 60 and 120 degrees, more preferred 90 degrees. 
     Moreover, the peristaltic pump  1  comprises an actuator  7  for selectively moving the tube carrier  4  relative to the rotary body  2  (i.e., if present, to the base  13  or housing  14  to which the rotary body  2  may be attached to) between a pump position (see  FIG.  1 A to  4 A ) in which the flexible tube  5  carried by the tube carrier  4  is positioned in engagement between the engagement section  6  and at least one, preferably at least two of the squeeze sections  3 , respectively, to allow for a pumping action when moving the rotary body  2  about the rotation axis A, and a release position (see  FIGS.  1 B to  4 B ) in which the flexible tube  5  carried by the tube carrier  4  is disengaged from the plurality of squeeze sections  3  to allow for free flow through the flexible tube  5 . The rotary body  2 , preferably via the housing  14 , as well as the actuator  7  may be attached to the same element of the peristaltic pump  1 , e.g. to the base  13  thereof. 
     The tube carrier  4  may comprise a cover section  15  for covering the functional elements of the peristaltic pump  1 , like the rotary body  2  and the engagement section  6 . The tube carrier  4  be preferably moveable relative to the rotary body  2  by a guide rail connection being provided directly or indirectly between these two elements, preferably between side walls  16  of the tube carrier  4  and the base  13  or the housing  14 . 
     In the pump position show in the Figures denoted with “A”, the arcuate engagement section  6  is here coaxially positioned with respect to the rotation axis A, which allows for a most efficient connection between the squeeze sections  3  and the engagement section  6  to squeeze a flexible tube  5  there between to allow for a sufficient pumping action. 
     The tube carrier  4  and the plurality of squeeze sections  3  are preferably configured such that, in the pump position, there are always at least two squeeze sections in functional position with respect to the arcuate engagement section  6  to allow for the engagement of the flexible tube  5  when being carried correspondingly by the tube carrier  4 . 
     To ensure a sufficient squeezing of the flexible tube  5  between the squeeze sections  3  and the corresponding arcuate engagement section  6 , the squeeze sections  3  can be axially biased outwards, i.e. away from the rotation axis or towards the arcuate engagement section  6  when facing the same. Hence, the peristaltic pump  1  allows for a sufficient and effective engagement of the flexible tube  5  between the respective squeeze section(s)  3  and engagement section  6  in the pump position, irrespective of the type and layout of the flexible tube  5  being used. 
     The tube carrier  4  can be biased towards the release position to thus ensure the flexible tube  5  in the release position be positioned such that it securely allows for a corresponding free flow. Preferably, the tube carrier  4  may comprise a lock element for locking the tube carrier  4  in the pump position so that, e.g. irrespective of the tube carrier  4  be biased towards release position, it can be securely held in the pump position to keep up the engagement of the flexible tube  5  between the respective squeeze sections  3  and the engagement section  6 . The lock element can then be released correspondingly when the tube carrier  4  needs to be moved from the pump position to the release position. The cooperating locking partner of the lock element can be position on another part of the peristaltic pump  1 , preferably the housing  14  or the base  13 . 
     The actuator  7  is preferably functionally connected (e.g. directly structurally connected) to the tube carrier  4  to allow for the movement of the tube carrier  4  relative to the rotary body  2 . This is preferably done by a lifting cylinder and/or a gear drive  75 , the latter being shown in detail in  FIGS.  4 A and  4 B . In the shown embodiment, the actuator  7  comprises a rotational shaft  70  at the end of which a gear  71  is provided. This gear  71  is in engagement with another gear section  72  of the gear drive  75 . The gear section  72  is rotatably connected to be moved about a second rotation axis B. A pin element  73  is provided at the gear section  72  and thus moved along an arcuate path upon rotational movement of the gear section  72  about the second rotation axis B. The pin element  73  is engaged with and guided within an engagement grove  74  of the tube carrier  4 . By operational action of the actuator  7 , the rotational shaft  70  is rotated, which rotational action is transferred to gear  71  and then further to gear section  72  which in turn moves the pin element  73  along the arcuate path. Due to engagement of the pin element  73  in the engagement grove  74 , the tube carrier  4  is lifted as is shown in the comparison of  FIG.  3 A to  3 B  to be thus moved from the pump position to the release position in which the flexible tube  5  is released to allow free flow. Preferably, the actuator  7  is moved in a reverse direction to move the tube carrier  4  from the release position back into the pump position. According to the shown embodiment, the actuator  7  comprises an electric motor  76  but may also comprise a magnetic drive, a pneumatic actuator and/or a hydraulic actuator or any other kind of actuators known in the prior art. 
     As is shown in the embodiment of  FIGS.  1  to  4   , the movement of the tube carrier  4  relative to the rotary body  2  here is a translational movement. In the shown embodiment, the tube carrier  4  is moved along an up/down direction. However, the transalational movement can also be along another direction alternatively or additionally. Also, the movement can comprise a rotational movement, if desired, dependent on the actuator  7  be used. 
     As can be seen from  FIG.  4 C , the arcuate engagement section  6  can be radially offset from the squeeze sections  3  with respect to the rotation axis A in the release position compared to their relative position in the pump position, the latter being exemplarily shown in  FIG.  3 A . Alternatively or additionally, the arcuate engagement section  6  can also be axially offset from the squeeze sections  3  with respect to the rotation axis A in the release position compared to their relative position in the pump position. 
     The peristaltic pump  1  as described herein above may be used in a pump system  100 , which is schematically shown in  FIG.  5   . The pump system  100  comprises the peristaltic pump  1  according to the present invention. Further, a flexible tube  5  is provided and functionally carried by the tube carrier  4 . Moreover, a product supply  8  is fluidly connected to an upstream end  50  of the flexible tube  5 ; here via a first connection section  17  of the peristaltic pump  1 . A product discharge section  9  is fluidly connected to a downstream end  51  of the flexible tube  5  (here via a second connection section  18  of the peristaltic pump  1 ) to thus allow for a product flow from the product supply  8  to the product discharge section  9  via the peristaltic pump  1 . The product discharge section  9  can, for instance, comprise a discharge opening or element  22 , like a nozzle, and may also comprise a mixing chamber  23  for mixing a number of beverage ingredients to produce a final beverage product to be dispensed via the product discharge section  9 , e.g., in a consumer&#39;s recipient R (e.g. cup, mug, bottle, etc.). 
     The product supply  8  may comprise a product container C or any other means for carrying a corresponding product, like a beverage ingredient or product (e.g. additives like flavours, minerals, caffeine and the like) and/or a sanitizing liquid. Alternatively or additionally, the product supply  8  may also comprise a liquid supply  10 , preferably a water supply and more preferred a hot water supply. The liquid supply  10  can be a liquid storage or an liquid connection for attachment of or connection to an external liquid source, like a water conduit. For heating up the liquid to be delivered, a heater or boiler  11  may be provided. A pump  20  may be provided to deliver a sanitizing liquid (e.g. hot water or a chemically based liquid) through the pump system  100  (i.e. its fluidic path) and particularly through the peristaltic pump  1  particularly when the tube carrier  4  is in the release position. 
     Additionally, an air supply  12  may be provided, which is preferably fluidly connected to the upstream end  50  of the flexible tube  5  for delivering gas like air through the pump system  100  (i.e. its fluidic path) and particularly through the peristaltic pump  1  particularly when the tube carrier  4  is in the release positon to evacuate the fluidic path or at least peristaltic pump  1 , preferably after a cleaning or sanitizing process. The gas may be delivered by a compressor  21  or any other type of pump. The gas be delivered may be a heated gas be heated by a heater  19 . 
     In the following, a method for pumping a fluid by the pump system  100  according to the present invention is described. 
     For product delivery, the tube carrier  4  is positioned or moved in the pump position. Then, a liquid product is pumped from the product supply  8  (e.g. the beverage ingredient container C and/or the liquid/water supply  10 ) by pumping action of the peristaltic pump  1  by rotational movement of the rotary body  2  about the rotation axis A towards the product discharge section  9 . 
     For sanitization, the tube carrier  4  is positioned or moved in the release position. Then, a fluid or liquid is delivered or pumped from the product supply ( 8 ) (e.g. the liquid/water supply and/or the air supply, if present) through the peristaltic pump  1 , i.e. the flexible tube  5 , towards the product discharge section  9 . Hence, the peristaltic pump  1  and in particular the flexible tube  5  can be cleaned/sanitized. Therefore, preferably hot water can be used from the water supply  10 . 
     To allow for a secure cleaning/sanitization, a subsequent evacuation and/or drying step may be performed by delivering gas (e.g. air) through the flexible tube  5  in the release position of the tube carrier  4  by use of the air supply  12 . Hence, in the cleaning/sanitization step, after the fluid has been pumped through the system  100 , the evacuation and/or drying step may be followed by pumping gas/air, preferably hot air, from the air supply  12  via the peristaltic pump  1  towards the product discharge section  9 . In a most preferred embodiment, the product discharge section  9  is cleaned/sanitized by the cleaning/sanitization step as well. Any sanitization liquid or gas for evacuating/drying can be further transferred to a drainage downstream the product discharge section  9 . 
     The present invention is not limited by the embodiment described hereinabove as long as being covered by the appended claims.