[ 001 ] The present invention relates to a pump, and in particular to a peristaltic pump, and a fluid delivery system comprising the pump .

[ 002 ] Peristaltic pumps are a type of positive displacement pump used for pumping a variety of fluids . A typical peristaltic pump comprises a flexible tube for conveying the fluid through compression of the tube in a peristaltic manner . Fluid is pushed or pulled through the tube by moving the region of compression along the length of the tube . Compression of the tube is typically achieved by mechanically driven rollers which pinch of f a section of the tube . A typical peristaltic pump thus comprises a plurality of rollers between which fluid is trapped : as the rollers rotate , the trapped fluid is transported through the tube towards the pump outlet . Peristaltic pumps are often used where the flow of fluid needs to be carefully metered, i . e . where small amounts of fluid need to be accurately delivered . Peristaltic pumps are thus widely used in medical applications , for example for delivering IV fluids to patients , and food and beverage applications .

[ 003 ] However, typical peristaltic pumps can suf fer from problems with the accuracy of fluid dosing . For example , some peristaltic pumps can suf fer from flat spots in fluid delivery, and pulsating fluid delivery .

[ 004 ] The present invention seeks to provide a peristaltic pump with improved accuracy of fluid delivery compared to prior art pumps . [ 005 ] Thus , according to the present invention there is provided a peristaltic pump comprising : a fluid inlet and outlet ; a carrier member having an outer surface ; flexible tubing for conveying a fluid which extends at least partially around the outer surface of the carrier member ; and a drivable compression roller ; wherein the carrier member and compression roller can be positioned adj acent one another to compress the flexible tubing therebetween, and the compression roller rotated about an axis of rotation to thereby cause the carrier member and flexible tubing to rotate about an axis of rotation, by which fluid within the flexible tubing can be conveyed along the flexible tubing between the inlet and outlet .

[ 006 ] The peristaltic pump of the present invention thus conveys fluid using the same principles as a conventional peristaltic pump, i . e . fluid is conveyed along flexible tubing by compressing the flexible tubing and moving the point of compression along the flexible tubing . However, in the peristaltic pump of the present invention, unlike a conventional peristaltic pump, rollers do not rotate about an internal central axis relative to flexible tubing which is fixed in position, for example within and relative to a housing or mani fold . Instead, in the pump of the present invention the flexible tubing moves relative to the compression roller, through rotation of the carrier member about its rotational axis , on which the flexible tubing is positioned, driven by rotation of the compression roller . Thus , in use when the compression roller and carrier member are positioned to convey fluid through the flexible tubing, with the flexible tubing compressed therebetween, the axis of rotation of the carrier member and the axis of rotation of the compression roller/ flexible tubing are in fixed positions relative to each other . In this way, greater accuracy of fluid delivery can be achieved compared to conventional peristaltic pumps . For example , the compression roller may have a circumference substantially smaller than that of the carrier member, meaning that rotation of the compression roller through a full 360 ° rotation corresponds to rotation of the carrier member, and hence the flexible tubing, through only a fraction ( arc ) of the circumference of the carrier member . For example , the ratio of the circumference of the compression roller to the carrier member may be from 1 : 10 to 1 : 15 or 1 : 20 , meaning that , for these ratios , a full 360 ° rotation of the compression roller would rotate the carrier member through 36 ° , 27 ° and 18 ° respectively . This arrangement allows for very accurate control of the amount of fluid being conveyed through the flexible tubing . However, the relative si zes of the compression roller and carrier member are not limited, and may be selected as desired according to the requirements of the pump .

[ 007 ] The peristaltic pump of the present invention thus comprises a carrier member having an outer surface on which the flexible tubing is positioned and extends at least partially around . The carrier member preferably takes the form of a rotatable wheel with the flexible tubing positioned around its outer circumference . For example , the carrier member may comprise circumferential flanges between which the flexible tubing may be positioned . The flanges may have a depth which is equal to or less than the thickness of the flexible tubing material . The flexible tubing preferably extends around the carrier member as a single turn coil .

[ 008 ] The flexible tubing used in the peristaltic pump of the present invention may be formed of any material which is suitable for the intended purpose of the pump, and in particular the fluid to be conveyed . For example , suitable materials may include polyvinyl chloride , silicone , polyurethane and natural rubber . For example , for delivery of a beverage or a beverage ingredient , a preferred material is silicone . The thickness of the tubing material may also be selected according to requirements , for example to be equal to or greater than the depth of circumferential flanges of the carrier member .

[ 009 ] In use , fluid enters the pump through the inlet from a fluid source , such as a fluid reservoir or container . Thus , the pump may comprise an inlet pipe or tube for insertion into a fluid reservoir through which fluid may be drawn into the pump through the flexible tubing .

[ 0010 ] As described herein, in use the flexible tubing moves relative to the rotational axis of the compression roller as the carrier member rotates , driven by the compression roller . Thus , in use the flexible tubing rotates with the carrier member about its rotational axis . To allow the flexible tubing to rotate in this way without twisting, the flexible tubing may be connected to the pump outlet via a fluid-tight movable j oint , such as a rotary j oint , to allow relative movement between the flexible tubing and the pump outlet .

Thus , in an embodiment of the pump of the present invention, the fluid flow path may comprise an inlet comprising a pipe or tube which in use is in fluid communication with a fluid source and also with the flexible tubing, and the flexible tubing extends from the inlet around the circumference of the carrier member to the pump outlet via a fluid-tight movable j oint , such as a rotary j oint . The flexible tubing may be connected to the pump inlet by a movable j oint , such as a rotary j oint .

[ 0011 ] The pump of the present invention further comprises a drivable compression roller positionable relative to the carrier member so as to compress the flexible tubing between the compression roller and carrier member . The compression roller is rotatable about an axis of rotation, and is preferably driven by a rotary drive , such as an electric motor . The compression roller is preferably rotatable in opposite directions , i . e . both forwards and backwards . In this way, the compression roller can be driven in a first direction to dispense fluid from the reservoir to a desired location through the flexible tubing, and can be driven in a second, opposite direction to allow fluid in the flexible tubing to be returned to the fluid reservoir . Driving the compression roller in the second direction also allows a cleaning fluid, such as water, to be drawn into the flexible tubing to clean the flexible tubing and thus help to prevent cross-contamination i f the pump i s being used to deliver a plurality of di f ferent fluids .

[ 0012 ] The compression roller preferably takes the form of a wheel or cylinder, and may have a circumference which is substantially smaller than the circumference of the carrier member . In this way, a full 360 ° rotation of the compression roller corresponds to rotation of the carrier member, and hence the flexible tubing, through only a small fraction ( arc ) of the circumference of the carrier member . The speci fic gearing, i . e . relative si zes of the compression roller and carrier member, to be used in a particular pump will depend upon the intended use of the pump . Thus , a smaller diameter compression roller relative to the carrier member will provide greater accuracy in fluid delivery, but will require a greater degree of or number of rotations to deliver the same amount of fluid as a compression roller having a greater diameter relative to the carrier member . The thickness/depth of the compression roller may be selected according to the corresponding dimensions and configuration of the carrier member and flexible tubing . For example , i f the carrier member comprises circumferential flanges to retain the flexible tubing in position then the compression roller may have a thickness/depth selected so the compression roller sits between the flanges to compress the flexible tubing . Alternatively, the compression roller may take the form of an elongate cylinder which can press against the flanges to compress the flexible tubing within the flanges , for example where the flexible tubing is formed from a material which has a thickness equal to or greater than the depth of the flanges . The pump of the present invention may comprise more than one compression roller, radially circumferentially spaced around the carrier member, according to the requirements of the pump . All , some , or only one of the compression rollers may be drivable , for example by an electric motor .

[ 0013 ] During operation of the pump it is possible that continuous flow of fluid through the flexible tubing may be interrupted due to gaps or "dead spots" in which fluid is absent from the flexible tubing. These dead spots may be more prevalent at points of greater curvature of the flexible tubing, for example where the flexible tubing first comes into contact with the carrier member downstream of the inlet, and where the flexible tubing leaves the carrier member going towards the outlet. To help ensure that the desired amount of fluid is delivered by the pump, the pump may be configured to recognize any dead spots, for example using a microswitch, and adjust the run of the motor accordingly to take the dead spot(s) into account.

[0014] The pump of the present invention may be used to accurately deliver small amounts of fluid in different applications, such as medical applications, or food and drink applications. For example, the pump may be used to dispense a beverage or beverage ingredient, such as a flavouring, vitamin, fibre, or caffeine. The pump may be configured to dispense the fluid, for example beverage or beverage additive, in a predetermined amount, for example by driving the compression roller for a predetermined length of time, preferably adjusted to take into account any interruptions in fluid flow due to dead spots, as discussed above.

[0015] The pump of the present invention may form part of a fluid delivery system for delivery of a fluid from a fluid reservoir to a desired location. For example, the pump may be located in a housing with a fitting for attachment to a fluid reservoir. Thus, a fluid delivery system may comprise a housing having a fitting to which a fluid reservoir may attached, such as by a screw- or push-fit. The housing may be openable and closable to allow for removal and replacement of a fluid reservoir . In embodiments , the carrier member of the pump may be formed integrally with a fitting for attachment to a fluid reservoir, which is removable from the fluid delivery system for replacement of the fluid reservoir . In these embodiments , the carrier member, fitting and/or fluid reservoir may all rotate together as a unit when the carrier member is rotated by the compression roller . The fluid delivery system preferably comprises a motor for driving the pump . The fluid delivery system preferably comprises a fluid inlet , such as a tube or pipe , attached to the flexible tubing inlet , which in use is inserted into the fluid in the fluid reservoir when the fluid reservoir is attached to the housing . The fluid delivery system preferably further comprises a fluid outlet , such as a noz zle , tap , dropper or mixer, attached to the flexible tubing outlet , for delivery of the fluid to the desired location . In embodiments , the fluid delivery system outlet may comprise mixing means by which di f ferent fluids from di f ferent fluid reservoirs may be mixed on delivery to a desired location . For delivery of a beverage or beverage ingredient , the fluid delivery system may comprise a platform on which a beverage receptacle , such as a glass or bottle , may be placed so as to be positioned directly below the fluid outlet for delivery of the fluid into the receptacle .

[ 0016 ] The fluid delivery system may comprise flow prevention means , for preventing flow of fluid from the system, for example when a fluid reservoir is being replaced . Unwanted flow of fluid may be messy and present hygiene issues . The flow prevention means may comprise a clamp for clamping or pinching the flexible tubing to prevent fluid from exiting . The flow prevention means may comprise a clamp for clamping or pinching the flexible tubing to prevent fluid from exiting. In embodiments where the fluid reservoir is replaced by opening the housing of the fluid delivery system, the flow prevention means may be activated whenever the housing is opened, thereby clamping or pinching the flexible tubing to prevent fluid flow whilst the housing is open, releasing the flexible tubing when the housing is closed.

[0017] The fluid delivery system may comprise a controller, such as a programmable computer, for controlling fluid delivery. For example, the controller may be pre-programmed to deliver a predetermined amount of fluid or may deliver fluid in an amount determined by a user input, for example via user input means such as a touchscreen. The controller may control fluid delivery based upon other inputs from the system, for example in response to sensor inputs recognizing dead spots in fluid flow, e.g. from a microswitch, and adjust the run of the motor accordingly to take the dead spot(s) into account. The controller may comprise a computer memory for storing different user profiles each having particular fluid delivery preferences for that user. The controller may comprise wireless technology, e.g. smart technology, so as to be controllable by a user remotely (e.g. a smartphone app) . The computer memory may be configured to store other information, such as the use history of the fluid delivery system, service history, and so forth.

[0018] The fluid delivery system may be useable with a plurality of fluid reservoirs simultaneously. Thus, for delivery of a beverage or beverage ingredient, the fluid delivery system may be able to deliver a plurality of different beverages or beverage ingredients, for example different flavourings, without a user needing to replace the fluid reservoir. The fluid delivery system may comprise a single pump according to the present invention which is in fluid communication with each of a plurality of fluid reservoirs, or may comprise a plurality of pumps. For example, the fluid delivery system may comprise a plurality of pumps each of which is for use with a separate fluid reservoir. The fluid delivery system outlet may comprise, for example, mixing means for allowing a plurality of different fluids from different fluid reservoirs to be delivered mixed together .

[0019] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

[0020] Figure 1 shows an embodiment of a pump, housing and fluid reservoir for use in a fluid delivery system according to the present invention;

[0021] Figure 2 shows the embodiment shown in Figure 1 with the housing removed;

[0022] Figure 3 shows the carrier member, flexible tubing and fluid reservoir of the embodiment shown in Figures 1 and 2;

[0023] Figure 4 shows an enlarged view of the carrier member and fitting of the embodiment shown in Figures 1 to 3;

[0024] Figure 5 shows the flexible tubing of the embodiment shown in Figures 1 to 4;

[0025] Figure 6 shows a cross-sectional view of Figure 4; [0026] Figure 7 shows an enlarged view of the flexible tubing of the embodiment shown in Figures 1 to 6;

[0027] Figure 8 shows an enlarged view of the pump and housing shown in Figure 1 with the housing closed;

[0028] Figure 9 shows an enlarged view of the pump and housing shown in Figure 8 with the housing opened;

[0029] Figure 10 shows an enlarged view of the pump and housing shown in Figures 8 and 9 with the fluid reservoir, carrier member and flexible tubing detached from the housing;

[0030] Figure 11 shows an embodiment of a fluid delivery system array incorporating a plurality of embodiments of a fluid delivery system according to the present invention features of which are shown in Figures 1 to 10;

[0031] Figure 12 shows an exploded view of the fluid delivery system array as shown in Figure 11; and

[0032] Figure 13 shows an embodiment of a mixer nozzle for use with the present invention.

[0033] Common reference numbers are used for the same features in each of the Figures. Not all features of the illustrated embodiments of the invention are shown in each of the Figures.

[0034] Referring to Figures 1 to 3, a pump (generally indicated by reference 1) according to the present invention is shown comprising a fluid inlet (not shown) and outlet 10. A further section of flexible tubing (not shown) will typically be attached to the outlet 10 to convey fluid from the pump 1 to the desired location. The pump 1 comprises a carrier member 12 and flexible tubing 14 extending around the outer surface of the carrier member 12 in a single turn . The pump 1 also comprises a drivable compression roller 16 which is shown in Figures 1 and 2 positioned against the carrier member 12 to compress the flexible tubing 14 therebetween . The compression roller 16 comprises an elongate cyl inder and is rotated by a motor 18 to thereby cause the carrier member 12 and flexible tubing 14 to rotate , by which fluid within the flexible tubing 14 can be conveyed along the flexible tubing 14 through peristaltic action . Also shown are a fluid reservoir 20 which attaches to the carrier member 12 through a fitting 22 , and a pump housing ( generally indicated by reference 24 without a cover ) . The carrier member 12 engages with the housing 24 through engagement member 13 , which proj ects from the upper surface of the carrier member 12 . The engagement member 13 engages with a slot 50 ( see Figures 9 and 10 ) in the underside of the housing 24 and is free to rotate within the slot 50 when the pump 1 is in use . In the embodiment shown in Figures 1 to 3 , the carrier member 12 , flexible tubing 14 , fitting 22 and fluid reservoir 20 form a single unit , as shown in Figure 3 , which is detachable from the pump housing 26 , as is more fully described below with reference to Figures 8 to 10 . Figure 1 also shows flow prevention means 26 , for clamping a section of flexible tubing downstream of the pump outlet 10 for preventing fluid flow from the pump 1 , for example when a fluid reservoir 20 is being replaced . The flow prevention means 26 is described further in more detail below with reference to Figures 8 to 10 .

[ 0035 ] The motor 18 is able to drive the compression roller

12 both forwards and backwards , to dispense fluid to a desired location in a first direction, and in the second, opposite direction to allow fluid in the flexible tubing 14 to be returned to the fluid reservoir 20 . Driving the compression roller 12 in the second direction also allows a cleaning fluid, such as water, to be drawn into the flexible tubing 14 to clean the flexible tubing 14 and thus help to prevent cross-contamination i f the pump 1 is being used to deliver a plurality of di f ferent fluids .

[ 0036 ] Figure 4 shows an enlarged view of the carrier member 12 and fitting 22 . Thus , the carrier member 12 is shown to have circumferential flanges 28 defining a circumferential channel 30 in which the flexible tubing 14 (not shown in Figure 4 ) is carried by the carrier member 12 . Figure 4 also shows an inlet tube 32 which extends within the fluid reservoir 20 (not shown in Figure 4 ) through which fluid enters the fluid delivery device .

[ 0037 ] Figures 5 to 7 show the connections between the inlet tube 32 , flexible tubing 14 , carrier member 12 and outlet 10 in more detail . Thus , the elongate inlet tube 32 has an inlet end 34 which extends within the fluid reservoir 20 (not shown) and an outlet end 36 which connects to the inlet of the flexible tubing 14 at inlet j unction 38 . The flexible tubing 14 extends in a single coil around the circumference of the carrier member 12 within channel 30 defined by flanges 28 . The flexible tubing outlet 40 connects to a movable rotary j oint 44 at outlet j unction 42 . The movable rotary j oint 44 is positioned within the engagement member 13 and is in fluid- tight communication with the pump outlet 10 through 0-ring 46 . The movable rotary j oint 44 allows for relative rotation between the flexible tubing 14 about the rotational axis of the carrier member 12 and the outlet 10 , to allow the outlet 10 to remain in a fixed position as the carrier member 12 rotates . Figure 6 also shows screw threads 48 by which the fitting 22 attaches to the fluid reservoir 20 (not shown in Figure 6 ) .

[ 0038 ] Figures 8 to 10 show how a fluid reservoir 20 may be detached from the housing 24 , for example to replace an empty reservoir 20 . Thus , Figure 8 shows the fluid reservoir 20 attached to the housing 24 , with the housing 24 in a closed position . Figure 9 shows the housing 24 in an open position, in which the outlet 10 is detached from the movable rotary j oint 44 within the carrier member 12 . Figure 9 shows the engagement member 13 held within the slot 50 on the underside of the housing 24 . When the housing 24 is in the open position, the engagement member 13 may be removed from the slot 50 and the unit comprising the carrier member 12 and fluid reservoir 20 may be removed as shown in Figure 10 .

[ 0039 ] Figures 8 to 10 also illustrate operation of the flow prevention means 26 . As shown, the flow prevention means comprises a clamp through which a further section of flexible tubing (not shown) for conveying fluid from the outlet 10 to the desired location would be held . When the housing 24 is in the closed position, as shown in Figure 8 , the flow prevention means is not activated and the flexible tubing is unconstricted within the flow prevention means 26 so that fluid can be conveyed therethrough . However, when the housing 24 is in the open position, as shown in Figures 9 and 10 , the flow prevention means moves upwards relative to the flexible tubing, which causes a constriction within the flexible tubing and thereby prevents fluid from flowing within the flexible tubing whilst the housing 24 is in the open position . When the housing 24 is returned to the closed position, as shown in Figure 8 , the flow prevention means 26 returns to the non-activated position, and fluid can once again flow through the flexible tubing .

[ 0040 ] Figures 11 and 12 show an array 100 of seven individual fluid delivery systems 102 according to the present invention, features of which are described with reference to Figures 1 to 10 . In this embodiment , each of the individual fluid delivery systems 102 is identical , and thus for ease of reference , reference numerals are provided in each Figure for one individual fluid delivery system 102 of the array 100 only . However, it will be understood that each of the individual fluid delivery systems 102 has the same features .

[ 0041 ] Thus , the illustrated embodiment of a fluid delivery system array 100 comprises seven individual fluid delivery systems 102 , each of which comprises a fluid reservoir 22 , a housing 24 and housing cover 52 , and pump 1 . However, it is to be understood that the fluid delivery systems 102 may be used individually, or in an array containing any desired number of fluid delivery systems 102 . The housings 24 are shown having covers 52 . The array 100 is held within a casing 56 which comprises a backplate 58 and a front plate 60 . The casing 56 also comprises platforms 54 upon which the fluid reservoirs 20 rest when the units comprising the carrier member 12 and fluid reservoirs 20 are attached to the housings 24 .

[ 0042 ] A fluid delivery system array 100 allows for a plurality of di f ferent fluids to be delivered to a desired location . For example , in the case of beverages , each of the fluid reservoirs 20 may contain a di f ferent beverage or beverage additive , such as a flavouring . Each fluid delivery system 102 is in fluid communication with an outlet for delivering fluid to a desired location, for example by flexible tubing . Each fluid delivery system 102 may be individually and separately in fluid communication with the outlet , or a plurality of fluid delivery systems may be commonly in fluid communication with the outlet , for example through a shared flexible tubing . As discussed herein, in the illustrated embodiment , each of the individual fluid delivery systems 102 of the array 100 has its own pump 1 , but a plurality of fluid delivery systems 102 may share a common pump 1 .

[ 0043 ] Figure 13 shows an embodiment of a mixer noz zle 200 for use with the present invention . The mixer noz zle 200 comprises a mixing chamber 204 having a plurality of chamber inlets 202 . The inlets 202 will typically be connected to one or more fluid delivery systems 102 , for example an array 100 , as described herein, for mixing di f ferent fluids . The mixer noz zle 200 further comprises an elongate outlet pipe 206 , which may be pos itioned at a desired location for delivery of the fluid, for example within a receptacle or bottle in the case of a beverage . The mixer noz zle 200 comprises an outlet 208 for delivery of the fluid .

[ 0044 ] It is to be understood that the various di f ferent individual features and aspects of the present invention may be used either individually with the general inventive concepts disclosed herein or in combination with any or all other features , and the Applicant reserves the right to claim any or all of said features either individually or in any combination .