GB2560734A

GB2560734A - Fluid delivery apparatus

Info

Publication number: GB2560734A
Application number: GB1704548.5A
Authority: GB
Inventors: Tiago De Lima Rodrigues Rui; Jaramillo Rosales Alfonso
Original assignee: University of Warwick
Current assignee: University of Warwick
Priority date: 2017-03-22
Filing date: 2017-03-22
Publication date: 2018-09-26
Also published as: GB201704548D0

Abstract

A fluid delivery apparatus comprises a plurality of deformable fluid conduits 12, 14, 16, 18 and a plurality of respective pressing members 20, 22, 24, 26 for selectively closing the fluid conduits by deforming a wall of the fluid conduits. An actuator 38 moves the pressing members between a first position in which the fluid conduits are at least partially open to permit fluid flow therethrough, and a second position in which the pressing members hold the fluid conduits in a fully closed condition. The pressing members apply pressure to the fluid conduits in the first position such that the fluid conduits are pre-stressed or partially deformed.

Description

(54) Title of the Invention: Fluid delivery apparatus Abstract Title: Fluid delivery apparatus (57) A fluid delivery apparatus comprises a plurality of deformable fluid conduits 12, 14, 16, 18 and a plurality of respective pressing members 20, 22, 24, 26 for selectively closing the fluid conduits by deforming a wall of the fluid conduits. An actuator 38 moves the pressing members between a first position in which the fluid conduits are at least partially open to permit fluid flow therethrough, and a second position in which the pressing members hold the fluid conduits in a fully closed condition. The pressing members apply pressure to the fluid conduits in the first position such that the fluid conduits are pre-stressed or partially deformed.

Figure 1

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Figure 10(b)

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TITLE - Fluid Delivery Apparatus

The present invention relates to fluid delivery apparatus, and more particularly, although not exclusively, to millifluidic delivery apparatus.

Millifluidics is a field which encompasses the design and construction of fluid transport systems and devices capable of providing millilitre flow volumes.

Commercial valves used at the millifluidic scale have limitations concerning the number of sections of tubing controlled (typically one or two sections of tubing), or the nature of the control of the valve, and may also rely on wetting of the component used to stop flow. Furthermore, the acquisition cost of commercial valves used at the millifluidic scale is usually high, which results in complex fluid control becoming expensive to realise. Control of commercially available valves also requires a good working knowledge of electronics, especially when a large number of components are to be used, and this may result in systems being overly complex and inaccessible to a range of potential users.

The energy consumption of commercially available solenoid valve systems can also be problematic. Energising solenoid valves, e.g. to close a tube or maintain a closed tube condition, generates unwanted heat, which may - depending on the nature of the fluids within the system - need to be dissipated to minimise heat transfer to the fluid.

There has now been devised fluid delivery apparatus which overcomes or substantially mitigates the aforementioned and/or other disadvantages associated with the prior art.

According to a first aspect of the present invention there is provided fluid delivery apparatus comprising at least one deformable fluid conduit, at least one pressing member for selectively closing the at least one fluid conduit by deforming a wall of the fluid conduit, and an actuator for actuating the at least one pressing member between a first position in which the at least one pressing member holds the at least one fluid conduit in a partially closed condition, and a second position in which the at least one pressing member holds the at least one fluid conduit in a fully closed condition, wherein the first and second positions represent extreme positions of the pressing member.

The first and second positions may correspond to respective at-rest and actuated positions of the at least one pressing member, or vice versa.

The fluid delivery apparatus according to the first aspect of the present invention may be advantageous principally as the at least one pressing member may hold the at least one fluid conduit in a partially-closed or pre-stressed condition even when the pressing member is in a first, e.g. at-rest or unactuated, condition. When actuated to the second position, the at least one pressing member may deform/press the at least one fluid conduit into a fully closed/occluded condition. The first position being an extreme position of the at least one pressing member may mean that the at least one fluid conduit is always held in at least a partially closed condition (ie the at least one fluid conduit may never be in a fully open condition). The first and second positions may represent opposing extreme positions of the pressing member (e.g. such that the freedom/range of movement of the pressing member is only between said positions).

The invention may reduce the force or torque needed to place the at least one conduit in a fully closed condition, ie a condition in which fluid flow is prevented through the at least one fluid conduit. This may beneficially reduce the effort expended by the actuator in closing the conduit.

A reduction in the force or torque needed to close the at least one fluid conduit may reduce the stresses placed on the at least one fluid conduit during use, and may also reduce the level of heat generated during operation of the apparatus. A reduction in the level of heat generated may reduce or remove the need for additional heat dissipation components, thereby reducing the cost and/or decreasing the complexity of manufacture of the fluid delivery apparatus.

The at least one pressing member may be movable between the first and second positions. The at least one pressing member may be linearly movable along a single axis between the first and second positions. The at least one pressing member may be slidable between the first and second position. The position of the at least one fluid conduit may be fixed relative to the at least one pressing member, such that movement of the at least one pressing member between the first and second positions closes the at least one fluid conduit.

The partially closed or pre-stressed condition may comprise a condition in which fluid flow is enabled through the at least one fluid conduit.

The partially closed condition may comprise a condition in which an internal dimension of the at least one fluid conduit is reduced, for example along at least one axis, relative to an internal dimension of the at least one fluid conduit in a fully open condition. The partially closed condition may comprise a condition in which an internal dimension of the at least one fluid conduit in a region held by the at least one pressing member is reduced, for example along at least one axis, relative to an internal dimension of the at least one fluid conduit in a region that is not held by the at least one pressing member.

An internal dimension (e.g. height/width) of the at least one fluid conduit in the partially closed condition may be reduced by at least 1 %, at least 5 %, at least 10%, at least 15%, at least 20%, at least 25%, at least 50%, or at least 70% relative to an internal dimension of the at least one fluid conduit in a fully open condition, for example relative to a maximum internal diameter of the at least one fluid conduit in a fully open condition.

The fully closed condition may comprise a condition in which fluid flow is prevented through the at least one fluid conduit.

The fully closed condition may comprise a condition in which an internal height of the at least one fluid conduit is zero, for example a condition in which opposing wall portions of the at least one fluid conduit in a region held by the at least one pressing member are in contact. The fully closed condition may comprise a condition in which opposing points located on the perimeter of an internal lumen of the at least one fluid conduit touch, for example opposing points located on the perimeter of an internal lumen in a region held by the at least one pressing member. The opposing points may be diametrically opposed, for example located on opposing ends of an internal diameter of the at least one fluid conduit.

The first and second positions may correspond to extreme positions of the at least one pressing member.

The actuator may be configured to prevent actuation of the at least one pressing member beyond the first and second positions. The actuator may be configured to prevent movement of the at least one pressing member in at least one direction of motion in the first and second positions, for example to prevent movement of the at least one pressing member in at least one direction of motion along a linear axis of motion in the first and second positions. The actuator may be configured to prevent the at least one fluid conduit from reaching a fully-open condition, for example a condition in which the at least one fluid conduit has a constant internal width or diameter around its perimeter.

The actuator may be incapable of actuating the at least one pressing member beyond the second position. For example, the maximum extent of motion of the at least one pressing member which may be achieved by the actuator may be the second position. Thus the at least one pressing member may be prevented from applying too much force to the at least one fluid conduit in use.

The actuator may comprise at least one stopping member for preventing movement of the at least one pressing member beyond the first/second position. The at least one stopping member may comprise an abutment or cam surface which prevents movement of the at least one pressing member beyond the first position. The at least one stopping member may comprise a coupling member for coupling the at least one pressing member to a motor of an actuator. The at least one stopping member may be defined by a coupling member, for example by an external surface of a coupling member. The at least one stopping member may comprise a barrier beyond which the at least one pressing member cannot pass. Thus the at least one fluid conduit may never reach a fully open condition when the at least one conduit is held by the at least one pressing member.

The at least one pressing member may comprise a projection and/or aperture for engaging the fluid conduit, for example for engaging an external surface of the fluid conduit. The projection or aperture may be curved/rounded in form.

The pressing member may comprise an aperture for receiving the fluid conduit. The fluid conduit may be held within the aperture of the pressing member, for example by frictional engagement between an outer surface of the fluid conduit and a wall defining the aperture.

The aperture may comprise a cross-sectional shape having at least one width/diameter which is less than a maximum external diameter of the at least one fluid conduit, for example a cross-sectional shape taken orthogonally relative to a longitudinal axis of the at least one fluid conduit when the at least one fluid conduit is held within the aperture. The aperture may comprise a cross-sectional shape having a variable diameter, for example a diameter which varies about the perimeter of the cross-sectional shape.

The aperture may comprise a non-circular cross-sectional shape. The perimeter of the aperture may comprise an inwardly projecting region, for example a region which projects radially inwardly toward the centre of the aperture. The inwardly projecting region may comprise a convex profile in the plane of the aperture, for example such that the aperture has a shape substantially corresponding to a crescent shape. The convex profile may reduce the stress applied to an external surface of the at least one fluid conduit by the at least one pressing member in use.

The pressing member may be movable between the first and second positions such that the shape of the aperture closes the fluid conduit in the second position.

The pressing member may comprise a projection for engaging an external surface of the fluid conduit.

The projection may comprise a convex profile, e.g. at its tip. The projection may be formed at an end of pressing member. The projection may exert a force on the external surface of the fluid conduit in the first position, for example a radial force toward a centre point of the fluid conduit.

The pressing member (e.g. the projection or aperture thereof) may be shaped and/or dimensioned to reduce the force needed to move the at least one fluid conduit to a fully closed condition. It may be shaped and/or dimensioned to reduce the variation in stress applied to an external surface of the at least one fluid conduit in use.

The actuator may comprise a motor for driving the at least one pressing member between the first and second positions. The motor may be capable of achieving a continuous range of motion, or may be capable of achieving a discrete range of motion. The motor may, for example, comprise a stepper motor.

The actuator may comprise a coupling member for selectively coupling the motor to the at least one pressing member. The coupling member may be rotatable, and may, for example, be rotatable about an axis disposed orthogonally relative to a linear axis of motion of the at least one pressing member. The coupling member may be rotatable whilst the at least one pressing member is movable, for example slidable, along a linear axis. Thus the at least one coupling member may convert torque from the motor into linear motion of the at least one pressing member in use.

The coupling member may be selectively engageable with the at least one pressing member in use. The coupling member may be shaped to selectively engage the at least one pressing member in use, for example shaped to selectively move the at least one pressing member between the first and second positions in use.

The coupling member may comprise at least one engagement surface, which may, for example, project outwardly, e.g. radially outwardly, from a main body of the coupling member. The at least one engagement surface may project outwardly from a main body of the coupling member in a direction which is substantially orthogonal to an axis of rotation of the coupling member.

The at least one engagement surface may be integrally formed with the coupling member, for example such that the at least one engagement surface represents a region of the coupling member comprising an increased width or diameter relative to the remainder of the main body of the coupling member.

The coupling member may be eccentric and/or may or may not comprise one or more lobes. The coupling member may comprise a series of peaks and troughs around its perimeter, e.g. corresponding to the first and second positions of the pressing member.

The at least one engagement surface may be defined by channels formed either side thereof, for example by regions of reduced width or diameter either side of the engagement surface. The at least one engagement surface may be defined by a region of the coupling member between adjacent channels formed in an outer surface of the coupling member. Pairs of adjacent engagement surfaces may be separated by a channel, for example by a region of reduced width or diameter relative to the width or diameter of the engagement surfaces. The at least one coupling member may comprise channels for receiving the at least one pressing member in the first position, and/or may comprise at least one engagement surface for actuating the at least one pressing member into the second position.

The at least one engagement surface may extend only partially about the perimeter of the main body of the coupling member, for example only partially about the circumference of the main body of the coupling member, such that the coupling member comprises a region of increased width or diameter in the region of the at least one engagement surface relative to the remainder of the main body of the coupling member.

The at least one engagement surface may be selectively engageable with the at least one pressing member, for example by rotation of the coupling member to selectively actuate the at least one pressing member between the first and second positions.

The at least one engagement surface may extend from the main body of the coupling member by a distance corresponding to the distance between the first and second positions. The depth of a groove or channel formed in an outer surface of the coupling member may correspond to the distance between the first and second positions. Since the distance by which the at least one engagement surface extends from the main body of the coupling member corresponds to the distance between the first and second positions of the at least one pressing member, the at least one pressing member may be prevented from moving beyond the second position in use.

The at least one engagement surface may contact the at least one pressing member when there is alignment, e.g. rotational/angular alignment, there-between.

The at least one engagement surface may be ramped or sloped, e.g. may extend gradually from the main body of the coupling member, for example such that there is a gradual transition between the first and second positions.

The motor may be configured to stop where the at least one pressing member lies at any position between the first and second positions. This may enable accurate control of the flow volume through the at least one fluid conduit in use.

The coupling member may comprise a plurality or multiple lobes/engagement surfaces. Two or more engagement surfaces/lobes may be of different length, e.g.

in a circumferential direction. The coupling member may be multiply eccentrically shaped.

The coupling member may comprise three or more engagement surfaces, e.g. four engagement surfaces.

The coupling member may comprise a plate-like member, e.g. having opposing major/flat surfaces and a minor/peripheral surface extending therebetween. The peripheral surface may comprise the engagement surface.

A plurality of coupling members may be provided in a side-by-side (e.g. stacked) arrangement. The plurality of coupling members may be driven by a single/common actuator.

In an alternative embodiment, the actuator may comprise a linear actuator, and may, for example, comprise a single solenoid valve. The solenoid valve may be lockable, for example by mechanical engagement, in the first and second positions.

The at least one fluid conduit may be resiliently deformable. The at least one fluid conduit may comprise an internal diameter of less than 10 mm or 7 mm. For example <1 /16” (< 1.6 mm) for microfluidics, or 1 /16” (1.6 mm) to W (6.35 mm) for millifluidics.

The fluid delivery apparatus may comprise milli- or micro-fluidic delivery apparatus, for example apparatus allowing millilitre or microliter flow rates through the at least one fluid conduit in use.

The fluid delivery apparatus may be beneficial in any of the following applications: cell growth apparatus; High Performance Liquid Chromatography (HPLC); chemical production; hydroponics; plant growth.

The fluid delivery apparatus may define a valve assembly. For example, the at least one pressing member may comprise a valve member which selectively allows the passage of fluid along the at least one fluid conduit in use.

The apparatus may comprise a controller for controlling operation of the actuator, for example for automatically controlling operation of the actuator. The controller may be pre-programmed to control operation of the fluid delivery apparatus, for example according to a set fluid delivery regimen. The apparatus may comprise a user interface for enabling input of a desired fluid delivery regimen by a user. The apparatus may comprise a sensor for sensing a position of the at least one pressing member. The sensor may provide feedback to the controller to allow for automatic adjustment of the position of the at least one pressing member in use.

The fluid delivery apparatus may comprise a plurality of pressing members, each for selectively closing a corresponding fluid conduit. Each of the plurality of pressing members may comprise a first position in which the pressing member holds a corresponding fluid conduit in a partially closed condition, and a second position in which the pressing member holds a corresponding fluid conduit in a fully closed condition, wherein the first and second positions correspond to extreme positions of the pressing members.

A single actuator or coupling member may act on a plurality of pressing members and/or conduits, e.g. concurrently.

Where the fluid delivery apparatus comprises a plurality of pressing members, the coupling member may comprise a plurality of engagement surfaces, each or which may be capable of selectively engaging any of the plurality of pressing members, thereby moving the pressing member that is engaged between the first and second positions.

The plurality of engagement surfaces may be regularly or irregularly spaced about the perimeter or circumference of the coupling member, for example depending on a desired operating configuration of the fluid delivery apparatus.

The spacing between adjacent engagement surfaces may be chosen such that during operation of the fluid delivery apparatus all of the pressing members are in the first position and/or all of the pressing members are in the second position and/or at least one of the pressing members is in the first position whilst at least one other of the pressing members is in the second position.

The fluid delivery apparatus may comprise a first configuration in which a first pressing member and a second pressing member are both in the first condition. The fluid delivery apparatus may comprise a second configuration in which a first pressing member and a second pressing member are both in the second condition. The fluid delivery apparatus may comprise a third configuration in which a first pressing member is in the first position and a second pressing member is in the second position.

According to a further aspect of the present invention there is provided fluid delivery apparatus comprising first and second deformable fluid conduits, first and second pressing members for selectively deforming and thereby closing a corresponding one of the first and second fluid conduits, and a common actuator for actuating the first and second pressing members between first positions in which the first and second pressing members hold the first and second fluid conduits in an at least partially open condition, and second positions in which the first and second pressing members hold the first and second fluid conduits in a fully closed condition, wherein the actuator has at least the following configurations:

• a first configuration in which the first pressing member and the second pressing member are both in the first condition;

• a second configuration in which the first pressing member and the second pressing member are both in the second condition; and • a third configuration in which the first pressing member is in the first position and the second pressing member is in the second position.

This aspect of the present invention may be advantageous principally as the apparatus has at least the first, second and third configurations defined above. These configurations may allow a larger variety of control options than known commercially available fluid delivery apparatus, which may provide greater control over fluid delivery regimens, and may reduce the number of components required and/or the complexity of control required to obtain complex fluid delivery regimens.

It will be appreciated that optional features of aspects of the present invention can be used interchangeably between aspects, where appropriate.

A practicable embodiment of the invention is described in further detail below with reference to the accompanying drawings, of which:

Figure 1 is a schematic top plan view of a first embodiment of fluid delivery apparatus according to the present invention in a first configuration;

Figure 2 is a schematic top plan view of the fluid delivery apparatus of Figure 1 in a second configuration;

Figure 3 is a schematic side view of a pressing tab for use with fluid delivery apparatus according to the present invention;

Figure 4 is a schematic top plan view of a coupling member for use in the fluid delivery apparatus of Figures 1 and 2;

Figure 5 is a schematic perspective view of a valve housing body for use with fluid delivery apparatus of the present invention;

Figure 6 is a schematic perspective view of a motor assembly for use with fluid delivery apparatus of the present invention;

Figure 7 is a schematic perspective view illustrating attachment of a coupling member as shown in Figure 4 to the motor assembly of Figure 6;

Figure 8 is a schematic perspective view illustrating attachment of the valve body housing of Figure 5 to the combined coupling member and motor assembly shown in Figure 7;

Figure 9 is a schematic perspective view illustrating assembly of the component parts of the fluid delivery apparatus of Figure 1;

Figure 10(a) is a schematic top plan view of a second embodiment of fluid delivery apparatus according to the present invention in a first configuration;

Figure 10(b) is a schematic top plan view of the fluid delivery apparatus of Figure 10(a) in a second configuration;

Figure 10(c) is a schematic top plan view of the fluid delivery apparatus of Figure 10(a) in a third configuration;

Figure 10(d) is a schematic top plan view of the fluid delivery apparatus of Figure 10(a) in a fourth configuration; and

Figure 10(e) is a schematic top plan view of the fluid delivery apparatus of Figure 10(a) in a fifth configuration.

The fluid delivery apparatus disclosed herein may be used for milli and microfluidic applications, e.g. for controlling fluid flow for applications such as reagent control, cell growth/cultures, high-performance liquid chromatography, hydroponics, etc. Particular examples of applications for which the apparatus may be beneficial concern complex mixing of reagents/ingredients in defined order and/or precise amounts.

A first embodiment of fluid delivery apparatus according to the present invention, generally designated 10, is described with reference to Figures 1 to 9.

The apparatus 10 comprises first 12, second 14, third 16, and fourth 18, fluid conduits, first 20, second 22, third 24, and fourth 26 pressing tabs, a coupling member 28 a valve body housing 30, and a motor assembly 32.

The fluid conduits 12,14,16,18 are resiliently deformable fluid conduits, and for millifluidic applications typically have diameters in the region of 1/16” (1.59 mm) to ¹/₄” (6.35 mm).

The pressing tabs 20-26 act as pinch valves in use such that closing of the fluid conduits is made possible from the tube exterior. Thus the interior of the tube can be simply maintained in a sterile or other controlled condition since it does not need to be in fluid communication with the valve itself.

The pressing tabs 20,22,24,26 are shown schematically in Figure 3, and are blocklike - i.e. generally cuboid - in form. Each pressing tab 20,22,24,26 has an aperture 34 for receiving a corresponding fluid conduit 12,14,16,18 with a friction fit. The apertures 34 are substantially crescent shaped in form in this example and the fluid conduits 12,14,16,18 are held within the respective pressing tabs 20,22,24,26 in a partially closed condition, ie in a configuration having a reduced diameter relative to a diameter in a fully open condition. A curved internal surface/edge of the aperture has been found to be beneficial, although other aperture shapes could be considered, such as rectangular openings, e.g. in the form of a letter-box opening.

The height of each aperture 34 is less than the external diameter of the conduit therein. Thus the conduit is deformed at the section held within the aperture 34.

The coupling member 28 is shown schematically in Figures 4 and 7. The coupling member 28 has a substantially cylindrical global form, but comprises a plurality of channels 36 formed in its outer surface so as to define a plurality of engagement members 38. The number and spacing of the channels 36, and hence the engagement members 38, is chosen depending on the desired configurations of the apparatus 10 that are available during use.

The coupling member 28 has a recess (not shown) which allows the coupling member 28 to fit to a corresponding projection 56 of a motor 50 of the motor assembly 32 in use. The projection form part of the rotor of the motor, which thereby turns the coupling member in use between different angular orientations for selective actuation of the pressing tabs.

The valve body housing 30 is shown schematically in Figure 5. The valve body housing comprises a main body portion 40 and a plurality of fixing structures 42. The main body portion 40 is substantially cylindrical in form, and has a central cylindrical aperture 44 which receives the coupling member 28 when the fluid delivery apparatus 10 is assembled.

The main body portion has conduit receiving apertures 46 and pressing tab receiving slots 48. The conduit receiving apertures 46 are dimensioned to hold the fluid conduits 12,14,16,18 with a close/friction fit, whilst the pressing tab receiving slots 48 are dimensioned to allow the pressing tabs 20,22,24,26 to slide within the slots 48 in use.

According to various examples of the invention the conduit receiving apertures are arranged to hold the conduits in a tangential orientation relative to the axis of rotation of the coupling member. The orientation of the conduits lies in a plane that is perpendicular to the axis of rotation of the coupling member in this example. The apertures may each have an axis that extends in a tangential direction and/or may be tubular in form, wherein the tube extends in the tangential direction.

In this example, e.g. as shown in Figs. 1 and 2, up to four conduits can be accommodated by a single coupling member, with each conduit extending in a generally perpendicular direction to its adjacent conduit(s) when viewed in plan. Opposing conduits may be arranged in a parallel arrangement. The set of four conduits thus makes up a generally rectangular array in use.

The motor assembly 32 is shown schematically in Figure 6, and comprises a stepper motor 50, and upper 52 and lower 54 base components. The stepper motor allows angular adjustment and control of the angular orientation of the rotor at least at a resolution sufficient to distinguish between the different projections and recesses of the coupling member 28. The motor comprises an upstanding projection 56, i.e. an extension of the rotor/output shaft of the motor, which is received by a recess of the coupling member 28, such that the motor 50 can rotatably drive the coupling member 28 in use.

The upper 52 and lower 54 base components comprise respective fixing structures 58,60, which allow the fixing structures 42 of the valve body housing 30 to be secured to the motor assembly 32, as shown schematically in Figure 8.

When the fluid delivery apparatus 10 is assembled, the upper 52 and lower 54 base components, the motor 52, and the valve body housing 30 are aligned, such that screws can be passed through the fixing structures 42,58,60 to attach the various components of the fluid delivery apparatus, along with a lid 62 having a bearing 64, as shown in Figure 9. The coupling member 28 is located within the cylindrical aperture 44 of the valve body housing 30.

The pressing tabs 20,22,24,26 are located within their respective pressing tab receiving slots 48, such that the pressing tabs 20,22,24,26 are slidable within the slots 48. The fluid conduits 12,14,16,18 are located within their respective conduit receiving apertures 46, such that the conduits 12,14,16,18 are fixed within the apertures 46 by frictional engagement.

In use, the motor 52 is actuated to rotate the coupling member 28 within the cylindrical aperture 44. Where the channels 36 of the coupling member 28 are in alignment with the pressing tabs 20,22,24,26, the fluid conduits 12,14,16,18 are held in a partially closed configuration, such that fluid flow is allowed through the fluid conduits 12,14,16,18. Where the engagement portions 38 of the coupling member 28 are in alignment with the pressing tabs 20,22,24,26, the pressing tabs 20,22,24,26 are moved within their slots 48. As the conduits 12,14,16,18 remain fixed whilst their respective pressing tabs 20,22,24,26 slide, the movement of the pressing tabs 20,22,24,26 acts to close the fluid conduits 12,14,16,18, thereby preventing fluid flow through the fluid conduits 12,14,16,18.

By varying the number and spacing of the channels 36 and engagement portions 38, different combinations of the conduits 12,14,16,18 can be placed in (partially) open and closed conditions.

For example, in Figure 1, the first 20 and third 24 pressing tabs are engaged by engagement portions 38, whilst the second 22 and fourth 26 pressing tabs are received within channels 36 of the coupling member 28. This leads to the first 12 and third 16 fluid conduits being closed, whilst the second 14 and fourth 18 fluid conduits are held in a partially closed condition (whilst still allowing fluid flow therethrough).

By rotating the coupling member 28 anticlockwise, to a position as shown in Figure 2, the second 22 and fourth 26 pressing tabs are engaged by engagement portions 38, whilst the first 20 and third 24 pressing tabs are received within channels 36 of the coupling member 28. This leads to the second 14 and fourth 18 fluid conduits being closed, whilst the first 12 and third 16 fluid conduits are held in a partially closed condition (whilst still allowing fluid flow therethrough).

An example of more complex control is shown with reference to the second embodiment of fluid delivery apparatus 100 shown in Figures 10(a)-(e). The embodiment of Figures 10(a)-(e) differs from the embodiment of Figure 8 only in the number and spacing of channels 136 and engagement portions 138 of the coupling member 128, and hence reference numerals remain the same for other components.

In Figure 10(a), the first 20 and third 24 pressing tabs are engaged by engagement portions 138, whilst the second 22 and fourth 26 pressing tabs are received within channels 136 of the coupling member 28. This leads to the first 12 and third 16 fluid conduits being closed, whilst the second 14 and fourth 18 fluid conduits are held in a partially closed condition (whilst still allowing fluid flow therethrough).

By rotating the coupling member 28 anticlockwise, to a position as shown in Figure 10(b), the first 20 and fourth 26 pressing tabs are engaged by engagement portions 138, whilst the second 22 and third 24 pressing tabs are received within channels 136 of the coupling member 28. This leads to the first 12 and fourth 18 fluid conduits being closed, whilst the second 14 and third 16 fluid conduits are held in a partially closed condition (whilst still allowing fluid flow therethrough).

By rotating the coupling member anticlockwise, to a position as shown in Figure 10(c), the first 20, third 24 and fourth 26 pressing tabs are engaged by engagement portions 138, whilst the second 22 pressing tab is received within a channel 136 of the coupling member 128. This leads to the first 12, third 16, and fourth 18 fluid conduits being closed, whilst the second 14 fluid conduit is held in a partially closed condition (whilst still allowing fluid flow therethrough).

By rotating the coupling member anticlockwise, to a position as shown in Figure 10(d), the first 20, second 22, and third 24 pressing tabs are engaged by engagement portions 138, whilst the fourth 26 pressing tab is received within a channel 136 of the coupling member 128. This leads to the first 12, second 14, and third 16 fluid conduits being closed, whilst the fourth 18 fluid conduit is held in a partially closed condition (whilst still allowing fluid flow therethrough).

By rotating the coupling member anticlockwise, to a position as shown in Figure 10(e), the second 22 and fourth 28 pressing tabs are engaged by engagement portions 138, whilst the first 20 and third 24 pressing tabs are received within channels 136 of the coupling member 128. This leads to the second 14 and fourth 18 fluid conduits being closed, whilst the first 12 and third 16 fluid conduits are held in a partially closed condition (whilst still allowing fluid flow therethrough).

In different examples of the invention, the coupling member may have regularly or irregularly arranged engagement portions. The engagement portions may be of equal or varying spacing around the circumference of the coupling member (e.g. varying angular spacing. Additionally or alternatively, the engagement portions may be of the same or different length in a circumferential direction.

Using the above described principles, each angular orientation of the coupling member can be assigned an associated combination of conditions of the pressing members (i.e. the pressing tabs being actuated or unactuated by the engagement portions of the coupling member). Simple control of the angular orientation of the coupling member can therefore be used to control which conduit, or combination of conduits, is open to allow fluid flow, and which conduit, or combination of conduits, is closed.

A controller, such as a programmable chip or programmable logic controller, can be provided with suitable machine readable instructions in the form of one or more module of code to receive angular position information of the motor and to control angular position adjustments as required. Each pressing tab may have associated therewith a status sensor so as to provide positive verification of the tab actuation status. That data may be fed to the controller, i.e. as part of a feedback control loop. Additionally or alternatively, flow in each conduit could be sensed and the readings provided to the controller.

Routines for different sequences of conduit opening and closing can be entered by a user such that control of the system can be automated thereafter by the controller.

One benefit of the system apparatus described herein is that the motor can be adjusted a relatively small amount to affect the condition of a plurality of fluid conduits at concurrently. When the desired condition is reached, the motor can be de-energised such that no power is needed to maintain a current position of the coupling member. The coupling member position can be held simply by the friction inherent in the motor. Additionally or alternatively, a latching mechanism could be put in place to positively retain the coupling member in its set position. Thus the system is energy efficient and simple to set up and program as required by a user.

In other examples, the coupling member and associated pressing tab and valve housing components can be stacked such that a single motor can operate a plurality of coupling members to control flow through respective sets of fluid conduits at once. In various embodiments stacks of two or three or more coupling members have been achieved to create a compact apparatus for controlling up to twelve or more fluid conduit pinch valves at once with a single motor.

When stacked the precise configuration/shape of each coupling member may or may not be identical. Similarly the angular orientation of the mounting of each coupling member to the motor could be the same or different. Thus the stacked arrangement offers significant flexibility in setting up bespoke flow control regimes for the user. The modular nature of the assembly means that setup is simplified and the cost of implementing a flow control solution is reduced compared to the more complex solenoid-based solutions that are currently commercially available.

Claims

Claims:

1. Fluid delivery apparatus comprising: at least one deformable fluid conduit, at least one pressing member for selectively closing the at least one fluid conduit by deforming a wall of the fluid conduit, and an actuator for actuating the at least one pressing member between a first position in which the at least one fluid conduit is at least partially open to permit fluid flow therethrough, and a second position in which the at least one pressing member holds the at least one fluid conduit in a fully closed condition, wherein the pressing member applies pressure to the fluid conduit in the first position such that the fluid conduit is pre-stressed or partially deformed.

2. The fluid delivery apparatus of claim 1, wherein the pressing member is at rest in the first condition.

3. The fluid delivery apparatus of claim 1 or 2, wherein the first and second positions represent opposing extreme positions of the pressing member, such that the available range of movement of the pressing member is only between said positions.

4. The fluid delivery apparatus of any preceding claim, wherein the actuator comprises a rotor.

5. The fluid delivery apparatus of claim 4, wherein the at least one pressing member is linearly movable between the first and second positions in a radial direction relative to the axis of rotation of the rotor.

6. The fluid delivery apparatus of claim 4 or 5, wherein the at least one fluid conduit is oriented in a tangential direction relative to the rotor.

7. The fluid delivery apparatus of any preceding claim wherein the actuator comprises at least one abutment formation for preventing movement of the at least one pressing member beyond the first and/or second position.

8. The fluid delivery apparatus of any preceding claim wherein the at least one pressing member comprises a projection and/or aperture for engaging the fluid conduit, the projection or aperture being curved in form.

9. The fluid delivery apparatus of any preceding claim, wherein the at least one pressing member comprises an aperture of height smaller than the diameter of the conduit and through which the conduit passes in order to maintain the prestressed or partially closed condition of the conduit passing therethrough.

10. The fluid delivery apparatus of claim 8 or 9, wherein the aperture is crescent shaped.

11. The fluid delivery apparatus of any preceding claim, wherein the actuator comprises an electric motor.

12. The fluid delivery apparatus of claim 11, wherein the actuator comprises a rotatable coupling member shaped to selectively actuate the at least one pressing member according to the angular orientation of the coupling member.

13. The fluid delivery apparatus of claim 12, wherein coupling member is selectively engageable with the at least one pressing member.

14. The fluid delivery apparatus of claim 12 or 13, wherein the coupling member comprises a plurality of engagement surfaces, which project outwardly from a main body of the coupling member, wherein the engagement surfaces are angularly spaced about the axis of rotation of the coupling member.

15. The fluid delivery apparatus of any one of claims 12-14, wherein the coupling member is eccentric.

16. The fluid delivery apparatus of any one of claims 12-15, wherein the coupling member comprises a series of peaks and troughs around its perimeter, the height difference between said peaks and troughs corresponding to the actuation distance between the first and second positions of the pressing member.

17. The fluid delivery apparatus of any one of claims 12-16, wherein the engagement surfaces are integrally formed with the coupling member.

18. The fluid delivery apparatus of any one of claims 12-17, wherein at least one engagement surface is sloped.

19. The fluid delivery apparatus of any one of claims 12-18, comprising a controller arranged to control the angular orientation of the coupling member to achieve alignment between the coupling member and one or more pressing member in use so as to actuate the one or more pressing member when said alignment is achieved.

20. The fluid delivery apparatus of any one of claims 12-19, wherein the coupling member comprises three or more engagement surfaces.

21. The fluid delivery apparatus of claim 20, wherein the engagement surfaces are of different length and/or angular spacing.

22. The fluid delivery apparatus of any one of claims 12-21, comprising a plurality of coupling members aligned on a common axis of rotation.

23. The fluid delivery apparatus of claim 22, wherein the coupling members are driven by a common actuator.

24. The fluid delivery apparatus of any preceding claim comprising a controller for controlling operation of the actuator automatically according to a predetermined fluid delivery regimen set by a user.

25. The fluid delivery apparatus of claim 24, comprising a sensor for sensing a position of the at least one pressing member and providing the sensor reading to the controller.

26. The fluid delivery apparatus of any preceding claim comprising a plurality of pressing members, each for selectively closing a corresponding fluid conduit.

27. The fluid delivery apparatus of claim 26, comprising three or more pressing members.

28. The fluid delivery apparatus of any preceding claim comprising three or more fluid conduits arranged at different angular orientations relative to the actuator.

29. Fluid delivery apparatus comprising first and second deformable fluid conduits, first and second pressing members for selectively deforming and thereby closing a corresponding one of the first and second fluid conduits, and a common actuator for actuating the first and second pressing members between first positions in which the first and second pressing members hold the first and second fluid conduits in an at least partially open condition, and second positions in which the first and second pressing members hold the first and second fluid conduits in a fully closed condition, wherein the actuator has at least the following configurations:

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