Assembly and method for dispensing liquid

Abstract

An assembly (3) for dispensing a liquid, in particular a colorant for paints, comprising a container (4) for containing the liquid, a pump (5), a valve (6), at least one dispensing opening (23, 24), and comprising or being associated with a controller (7) arranged to operate the pump (5) and the valve (6) to draw liquid from the container (4) and to dispense liquid via the opening (23, 24), and to operate the pump (5) and the valve (6) to dispense liquid via the dispensing opening (23, 24). 24) flushes the liquid from the pump (5) to the container (4).

Description

[0001] The present application is a divisional application of patent application No. 201580049378.3 (PCT / EP2015 / 071375) filed by the applicant on September 17, 2015 and entitled “Components and methods for dispensing liquids”. Technical Field

[0002] The present invention relates to an assembly and method for dispensing a liquid, particularly a paint colorant. Background Art

[0003] EP 1 492 970 relates to a valve assembly for a fluid dispenser, comprising a housing having at least a first opening and a second opening, a valve member mounted in the housing, the valve member being rotatable about an axis and comprising a first channel extending along the axis and communicating with the first opening in the housing, and at least two outlet channels extending radially from the first channel to the periphery of the valve member, wherein each radially extending outlet channel can be aligned with the second opening by rotating the valve member.

[0004] EP 1 688 652 relates to a similar valve assembly, wherein at least one of the housing and the valve member is made of a synthetic material, and the assembly further comprises a spring which urges the valve member towards or to the inner wall of the housing.

[0005] US 2,985,339 relates to a dispenser for metering a predetermined amount, comprising a valve member (indicated by reference numeral 36 in the figure of US 2,985,339). Figure 6 The valve member 36 shown in the normal rest position has a recess 36a in its outer cylindrical surface opposite the discharge opening 35. … The valve member 36 has two radial valve passages 54 which are at right angles to each other and intersect at the axis of the valve member. ”

[0006] US2012 / 250451 relates to a method for homogenizing a liquid, in particular a colorant for a paint, in a container, comprising the steps of extracting the liquid from the container at a first flow rate (S1) and then returning the liquid to the container at a second flow rate (S2) higher than the first flow rate (S1).

[0007] In colorant dispensers, e.g. for paints, purging, i.e. dispensing a small amount of colorant to clean the dispensing opening and thus reduce the risk of so-called mistints due to nozzle blockage (e.g. caused by colorant drying at the dispensing opening), is a common and effective practice. However, purging means a waste of colorant.

[0008] It is an object of the present invention to provide effective cleaning of the dispensing opening and also to reduce or prevent this waste. Summary of the invention

[0009] The present invention relates to an assembly comprising a container for containing a liquid, a pump, a valve, at least one dispensing opening, i.e. an opening which is connected to the outside of the pump at least during dispensing to dispense liquid from the assembly into, for example, a vessel, and comprises or is associated with a controller which is arranged to operate the pump and the valve to draw liquid from the container to dispense the liquid via the opening and to operate the pump and the valve to purge the liquid from the pump to the container via the dispensing opening.

[0010] In one embodiment, the assembly comprises at least one further dispensing opening, e.g. having a diameter different from that of the first dispensing opening, e.g. smaller to allow more precise dispensing or larger to allow faster dispensing, and wherein the controller is arranged to operate the pump and the valve to flush the liquid from the pump to the container via the at least one further dispensing opening, preferably via all dispensing openings in sequence. In another embodiment, the valve connects the container to the pump in a first position and connects the pump to the dispensing opening or openings in a second or further position.

[0011] In another embodiment, the valve comprises a rotatable valve member, such as a valve ball, a cartridge or a disc, and the dispensing opening or openings are defined in the valve member, for example, as a channel or channels extending radially or axially in the valve member, respectively. Thus, the liquid is dispensed directly from the valve member, for example, through a larger opening in the valve, for example in the housing of the valve, preferably preventing the liquid from contacting the larger opening.

[0012] With the present invention, the dispensing opening can be cleaned by flushing with the colorant itself, however, since the flushed colorant is returned to the container, waste is reduced or completely prevented.

[0013] In a refinement, the openings are all located within 120° of a rotation of the valve member relative to each other, preferably within 110°. Thus, the total rotation required to flush all openings is limited and operation is facilitated.

[0014] The controller may be integrated with or associated with other parts of the assembly, for example, positioned in the dispensing position and connected to the other components when the other components are in the dispensing position.

[0015] In another embodiment, which may be used outside the context of flushing as described above, in one position of the valve, at least the pump is off and the controller is arranged to determine whether and if so, to what extent the medium contains air, preferably by measuring the compressibility or expansibility of the medium, for example by measuring the resistance or stroke of the pump. In a refinement, in one position of the valve, all aspiration and dispensing openings and routes are closed.

[0016] If the liquid within the pump allows more compression or expansion than the liquid itself, this is an indication that the liquid contains air. Liquids can contain air as a result of, for example, production or mixing of liquids or leaking seals in empty containers, refill containers or components. The extent of the displacement provides an indication of the root cause. The pump status and / or container filling condition can be recorded and communicated to an operator and / or service representative, for example by means of a signal and / or log.

[0017] In another embodiment, the valve comprises a variable opening and / or a plurality of different openings, and the controller is arranged to determine whether there is resistance to flow of the liquid over the openings. This can be achieved, for example, by precisely controlling the valve and / or shaping the openings, such as ovals, diamonds or ellipses, to vary the overlap between the internal openings and / or to provide two or more channels with different diameters and / or different effective cross-sections, thereby setting the resistance to flow.

[0018] This provides a means for determining the condition of the liquid, for example by measuring the resistance to flow, for example at different openings or overlaps, from the control of the motor driving the pump. The overlap and / or shape and / or surface and / or length (in the direction of flow) of the openings will affect the shear in the liquid, and for example for shear thinning and / or shear thickening liquids this will provide information whether a certain viscosity yield value is still present, which can be used as an indication of the condition of the liquid.

[0019] The measurement of (an indicative parameter of) compressibility, expandability or resistance to flow may be performed automatically, for example, periodically and / or outside of operating hours, and a signal generated to notify an operator or service representative.

[0020] In other embodiments, the controller is arranged to automatically flush the dispensing opening and perform said measurements, for example periodically and / or outside of operating hours.

[0021] In another embodiment, the pump is a positive displacement pump, preferably a reciprocating pump, preferably a piston pump.

[0022] The invention also relates to a method for dispensing a liquid, in particular a colorant for a paint, from an assembly comprising a container for holding the liquid, a pump, a valve and at least one dispensing opening, comprising the steps of drawing the liquid from the container and dispensing the liquid from the dispensing opening, and is characterized in that the liquid is flushed from the pump into the container via the dispensing opening.

[0023] In one embodiment, the assembly comprises a further dispensing opening and wherein the liquid is flushed from the pump to the container via the further dispensing opening.

[0024] In another embodiment, the pump is closed by means of a valve and the degree of compressibility or expansibility of the liquid in the pump is determined.

[0025] In another embodiment, the method includes varying the openings, for example between a pump and a container, generating a flow of liquid through the different openings, and determining the flow resistance in the liquid over the different openings.

[0026] In the framework of the present invention, the term "liquid" is defined as any flowable material comprising a liquid phase, thus including suspensions and emulsions. Colorants usually contain high density pigments or particles suspended in a (unstable) liquid binder / solvent solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The disclosed invention will be further explained with reference to the accompanying drawings, in which currently preferred embodiments of the invention are schematically shown.

[0028] Figure 1 is a perspective view of a portion of the disclosed device for dispensing viscous liquids.

[0029] Figure 2 Is applicable to Figure 1 A cross-sectional side view of a disclosed valve assembly in a device.

[0030] Figure 3 yes Figure 2 A detailed view of a portion of a valve assembly.

[0031] Figure 4 Yes Figure 3 A cross-sectional front view of a valve assembly is shown.

[0032] Figure 5A and 5B The valve is shown in different positions with Figure 3 Same details.

[0033] Figure 6 A portion of another embodiment is shown including different valves at seven positions. DETAILED DESCRIPTION

[0034] Figure 1 The main parts of an example of a device 1 for dispensing viscous liquids such as colorants or dyes are shown. This particular dispensing device includes a turntable 2 rotatable about a vertical axis by a drive (not shown) to rotate the turntable 2 between discrete positions. A plurality of assemblies 3 are mounted on the turntable 2, each of which includes a container 4 for containing a liquid, a pump 5 and a valve 6. Further details of the device and the turntable are disclosed in U.S. Pat. No. 6,273,298, the contents of which are incorporated herein by reference.

[0035] Figures 2 to 4A cross section of a pump 5 and a valve 6 is shown. The pump 5 is a piston pump and comprises a piston rod 5A equipped with a piston 5B, which is positioned in a cylinder 5C of the pump 5, and an upper flange 5D. The flange 5D can be engaged by a controller 7, which comprises an actuator (not shown) adapted to move the piston rod 5A and the piston 5B upwards during an intake stroke, and downwards during a dispensing stroke, and an actuator (not shown) operating the valve 6.

[0036] The controller 7 and the actuator are stationary and are arranged to position one of the assemblies 3 in line with the actuator so as to be able to actuate the pump 5 and the valve 6. The cylinder 5C is mounted on top of the pump housing 9, defines a cavity 10, and also includes an inlet passage 11 which is separate from the cavity 10 and is adapted to be in fluid communication with the container 4, such as Figure 1 shown.

[0037] The valve housing 12, including a cover 12A, is attached to the lower part of the pump housing 9 by respective flanges 13, 14. The valve member, in this example a ball 15, is assembled in the housing 12 by means of two annular bearings 16A, 16B made of, for example, a polymer material, such as PTFE (Teflon). The valve member 15 is provided with a rod 17, by means of which the valve member 15 can be rotated about the axis A by means of a corresponding actuator. The valve housing 12 also defines a chamber 18, which is defined in its upper part by a first opening 19, through which the chamber 18 communicates with the chamber 10 of the pump housing 9. The valve housing 12 also includes a second opening 20 at its bottom and a third opening 21 communicating with the inlet channel 11 in the pump housing 9. The valve member 15 includes a first channel 22, which extends along the axis A and communicates with the first opening 19 in the housing 12. It also comprises at least two dispensing openings, in this example in the form of outlet channels 23, 24, and an inlet channel 25, both of which extend radially from the first channel 22 to the circumference of the valve member 15. In this particular embodiment, the diameter of one of the outlet channels 23 is smaller than the diameter of the other 24, and the diameters of both outlet channels 23, 24 are smaller than the diameter of the inlet channel 25. Furthermore, both diameters are smaller than the diameter of the outlet opening 20 in the housing 12, and the central axes of the channels 23-25 ​​are all located on the same cross-sectional plane through the valve member 15, and are respectively separated by, for example, 30° and 100°.

[0038] Figures 2 to 4The entry position of the valve member is shown, wherein the inlet channel 25 of the valve member 15 is aligned with the third opening 21 of the valve housing 12 and, therefore, with the inlet channel 11. In other words, the container is in communication with the chamber 10 and the cylinder 7 in the pump housing 9. In this position, the chamber 10 and the cylinder 7 can now be filled with a desired amount of liquid from the container by moving the piston 6 upwards by a desired or predetermined length. It should be noted that in this position, the inlet channel 22 temporarily serves as an outlet channel.

[0039] Once the appropriate amount of liquid is aspirated, the valve member 15 can be rotated to the desired dispensing position, i.e., until the desired dispensing passages 23, 24 are aligned with the opening 20 in the housing, and the piston 6 can be moved downward to dispense the desired or predetermined amount from the opening 20. If the amount of liquid is relatively small and / or the dosage should be precise, a relatively narrow output passage 23 is appropriate, and if the amount is relatively large and / or should be dispensed quickly, a relatively wide output passage 24 is appropriate. Thus, the valve assembly can be customized and, if desired, dispense viscous liquids accurately and / or quickly without having to replace the valve assembly or parts of the valve assembly.

[0040] During the flushing period, Figure 5A and 5B As shown, the valve member 15 is rotated until the desired dispensing channel to be flushed is Figure 5A The larger diameter channels and Figure 5B The smaller diameter channel in the housing 12 is aligned with the third opening 22 in the housing 12, which is connected to the container 4. In these positions, the piston 6 moves downward to flush a predetermined amount of liquid back to the container 4 through the dispensing channel.

[0041] Figure 6 Another embodiment of a valve according to the invention in seven positions is shown. In this embodiment, the radial dispensing channels 23, 24 are separated by 108°, and the inlet channel 25 is positioned between the dispensing channels. These positions are, in order, entry or return of liquid via the inlet channel 25, flushing of the larger diameter dispensing channel 24 by returning liquid to the container, flushing of the smaller diameter dispensing channel 23 by returning liquid to the container, closing all suction and dispensing openings of the pump and routing fluid, dispensing via the smaller diameter dispensing channel 23, dispensing via the larger diameter dispensing channel 24, and dispensing via the inlet channel 25.

[0042] Of course, the invention is not limited to the embodiments disclosed above but can be varied in many ways within the scope of the claims.

Claims

1. A device (1) for dispensing a colorant for a paint, comprising a plurality of components (3), each component comprising a container (4) for containing a liquid, a pump (5), a valve (6), at least one dispensing opening (23, 24), and a controller (7), the controller (7) being arranged to operate the pump (5) and the valve (6) to extract the liquid from the container (4) and to dispense the liquid via the dispensing opening (23, 24), and to operate the pump (5) and the valve (6) to flush the liquid from the pump (5) to the container (4) via the dispensing opening (23, 24), characterized in that The valve (6) closes at least the pump (5) in another position, and wherein the controller (7) is arranged to determine whether the liquid in the pump (5) is compressible or expandable.

2. A device (1) as claimed in claim 1, each component comprising at least one further dispensing opening (24), for example, having a diameter different from the diameter of the first dispensing opening (23), and wherein the controller (7) is arranged to operate the pump (5) and the valve (6) to flush the liquid from the pump (5) to the container (4) via the at least one further dispensing opening (24), preferably via all dispensing openings (23, 24).

3. A device (1) as claimed in claim 1 or 2, wherein the valve (6) connects the container (4) to the pump (5) in a first position and connects the pump (5) to the dispensing opening (23, 24) or a dispensing opening (23, 24) in a second position or another position.

4. The device (1) according to any one of the preceding claims, wherein the valve (6) comprises a rotatable valve member (15) and the dispensing opening (23) or the plurality of dispensing openings (23, 24) are defined in the valve member (15).

5. The device (1) as claimed in claim 4, wherein the openings (23, 24) are both located within 120°, preferably within 110°, of a rotation of the valve member (15) relative to each other.

6. A device (1) as claimed in any of the preceding claims, wherein the valve (6) comprises a plurality of different openings (23, 24) and / or a variable opening, and wherein the controller (7) is arranged to determine whether there is a flow resistance in the liquid at the openings (23, 24).

7. The device (1) according to any of the preceding claims, wherein the controller (7) is arranged to automatically flush the dispensing opening (23, 24) and / or to determine the compressibility, expandability and / or flow resistance.

8. The device (1) according to any of the preceding claims, wherein the pump is a positive displacement pump, preferably a reciprocating pump, preferably a piston pump (5).

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