Abstract
The present disclosure relates to a container (1) for mixing paint comprising a paint cup (2) comprising a base portion (3) and sidewall portions (4) enclosing a receptacle volume (5), and having an opening (6) opposite to the base portion(3); a rotatable mixing element (17) disposed in the receptacle volume (5); and a coupling means (19) for operatively connecting the rotatable mixing element (17) to an actuator (30) configured to drive the rotatable mixing element (17). A paint mixing apparatus (26) comprising one or more ports (27) configured to accommodate such paint mixing container (1) and comprising an actuator (30) configured to drive the rotatable mixing element (17) and a process for mixing paint making use of such paint mixing container (1) are also disclosed.
Claims
1. A container for mixing paint comprising: a paint cup comprising a base portion and sidewall portions enclosing a receptacle volume, and having an opening opposite to the base portion, a rotatable mixing element disposed in the receptacle volume, and a coupling means for operatively connecting the rotatable mixing element to an actuator configured to drive the rotatable mixing element.
2. The container according to claim 1, wherein the rotatable mixing element comprises a propeller with one or more mixing blades, such as three or more mixing blades, optionally forming or provided with scraping elements, wherein the mixing blades can be symmetrically arranged around the axis of rotation of the mixing element.
3. The container according to any one of claim 1 or 2, wherein the paint cup has a rotation symmetrical shape, such as a cylindrical or a truncated conical shape.
4. The container according to claim 3, wherein the rotatable mixing element is disposed with its center of gravity along the rotation symmetry axis of the paint cup and/or in an orientation such that it rotates around an axis corresponding to or parallel to the rotation symmetry axis of the paint cup.
5. The container according to any one of claims 1 to 4, wherein the coupling means is at one end connected to the rotatable mixing element and has a coupling portion at the opposite end, which faces the outside of the paint cup and is shaped and configured to be engaged by a matching connecting part of the actuator.
6. The container according to any one of the preceding claims, further comprising a lid detachably connected to the paint cup to close the opening of the paint cup, wherein the lid preferably comprises an outlet for the paint, which can in particular be configured to allow for coupling to a paint applicator device, such as a spray gun, and wherein optionally a filter is installed inside the lid.
7. The container according to any one of the preceding claims, wherein the rotatable mixing element is mounted to the base portion of the paint cup, preferably in the center of the base portion, or is mounted to the lid, preferably in the center of the lid, for operatively connecting the rotatable mixing element to the actuator via the coupling means.
8. The container according to claim 7, wherein the base portion of the cup or the lid comprises a feedthrough as a mount for the coupling means.
9. The container according to any one of claims 1 to 8, further comprising a sealing member such as a rubber gasket for a leak tight operative connection of the rotatable mixing element to the actuator via the coupling means.
10. The container according to any one of the preceding claims having a receptacle volume in the range from 0.1 L to 2.0 L.
11. The container according to any one of the preceding claims, wherein the container or at least one component thereof is disposable and/or is made of a plastic material.
12. A paint mixing apparatus comprising one or more ports configured to accommodate a paint mixing container according to any one of claims 1 to 11 and comprising an actuator configured to drive the rotatable mixing element.
13. The paint mixing apparatus according to claim 12, wherein the actuator comprises an electrical or pneumatic drive and/or wherein the at least one port comprises means to retain the container during the mixing operation.
14. The paint mixing apparatus according to any one of claim 12 or 13, wherein the actuator comprises a connecting part arranged at the portion of the port facing the base portion or the opposite opening of the paint cup, respectively, and configured to releasably engage the coupling means.
15. A process for mixing paint comprising: Providing a container according to any one of claims 1 to 11, Introducing one or more paint components to be mixed into the paint cup in desired amounts, Optionally closing the opening of the paint cup with a lid, and Mixing the one or more paint components by driving the rotatable mixing element by operation of the actuator, for example using a paint mixing apparatus according to any one of claims 12 to 14.
Description
[0036] The present invention will be further illustrated in the following by reference to the appended drawings, wherein:
[0037] FIG. 1 represents a cross-sectional schematic view of an exemplary embodiment of a paint mixing container according to the present invention having integrated rotatable mixing means mounted to the base portion of a paint cup;
[0038] FIG. 2 represents a cross-sectional schematic view of a variant to the paint mixing container according to FIG. 1 having a snap lid with ventilation means;
[0039] FIG. 3 illustrates a paint mixing apparatus in accordance with the present invention with a paint mixing container as depicted in FIG. 1 mounted thereto, wherein the container and the portion of the apparatus receiving and coupling to the container are shown in cross-section;
[0040] FIG. 4 represents a cross-sectional schematic view of another exemplary embodiment of a paint mixing container according to the present invention with rotatable mixing means mounted to the lid of the paint cup;
[0041] FIG. 5 represents a cross-sectional schematic view of another exemplary embodiment of a paint mixing container according to the present invention with a liner-support assembly; and
[0042] FIG. 6A-E illustrates various exemplary configurations of a rotatable mixing element that can be used in paint mixing container according to the present invention.
[0043] In the drawings like reference numbers are used to designate corresponding features.
[0044] The paint mixing container 1 shown in FIG. 1 comprises a paint cup 2 with a truncated conical shape, which is symmetric with respect to the depicted central rotation axis R. The paint cup 2 has a flat circular base portion 3 and sidewall portions 4 extending therefrom to define a receptacle volume 5 in the interior of the cup 2. The receptacle volume 5 can for example have a volume in the range of 100 mL to 1000 mL, such as about 300 mL, 600 mL or 900 mL. The cup 2 is open at its top, i.e. opposite to the base portion, having a respective opening 6 through which the paint components to be mixed can be introduced into the receptacle volume 5. The sidewall portions 4 are provided with an external thread 7 at their upper end adjacent the opening 6.
[0045] The container 1 comprises moreover a lid 8 for closing the opening 6 of the paint cup 2. The lid 8 has for this purpose at its lower end a ring-shaped portion 9, which is provided on its internal surface with a thread 10 that matches the external thread 7 on the upper end of the sidewalls 4 of the cup 2 and can be engaged therewith. At the ring-shaped portion 9 furthermore a sealing lip 11 is formed, which engages with the interior surface of the sidewalls 4 of the cup 2 when the lid 8 is installed thereon to seal it. The lid 8 furthermore comprises a conical wall portion 12, which tapers from the ring-shaped portion 9 to a tubular outlet 13. The tubular outlet 13 may be provided with a thread 14, for example as shown on its external surface, to allow for coupling to a paint application device (not shown), either directly or indirectly via an appropriate adapter. A filter 15, for example in the form of a circular plastic sieve, can be fixed inside the lid 8, for example by being mounted or press fixed to an annular groove or matching receiving portion 16 in the conical wall portion 12. In the embodiment shown in FIG. 1 the lid 8 is likewise symmetric with respect to the central rotation axis R and has a height which corresponds to about half of the height of the paint cup 2.
[0046] The paint mixing container 1 furthermore contains a rotatable propeller-type mixing element 17, which is disposed in the receptacle volume 5 of the paint cup 2. The rotatable mixing element 17 has a plurality of (in the depicted example four) mixing blades 18, which extend radially from its center and are arranged symmetrically with a constant angle between each pair of adjacent blades. The mixing element 17 is mounted in the lower part of the paint cup 2, close to the base portion 3, in an orientation such that it rotates upon operation around the axis R. The rotatable mixing element is thus in a centrosymmetric arrangement with respect to the rotation symmetry axis R of the paint cup 2 and the lid 8. The mixing blades 18 herein rotate in a plane that is substantially perpendicular to the axis R. The mixing blades can each individually be oriented perpendicular (as depicted) or be inclined under an angle with respect to their rotational direction. Various different shapes, sizes and geometries of the rotatable mixing element can be used. For example, the mixing blades can have a spoon-like or oval shape and be spaced from the sidewalls 4 and the base portion 3 of the paint cup 2 as depicted in FIG. 1. The mixing blades may however also have another form such as for example a trapezoidal shape and/or be dimensioned such that they (almost) reach to or actually contact the adjacent sidewalls 4 and/or the base portion 3, as indicated by the dashed lines in FIG. 1. In such configuration the mixing blades may also act as scraping elements helping to avoid deposits that stick to the sidewall portions 4 or the base portion 4, respectively. As described beforehand, scraping elements may also be provided as separate components attached to the rotatable mixing element 17.
[0047] In the embodiment shown in FIG. 1 the rotatable mixing element 17 is mounted to the base portion 3 of the paint cup 2 by means of coupling means 19. The coupling means 19 comprises a rotary shaft, which is at its upper end connected to the rotatable mixing element 17 and has a coupling portion 20 at its opposite end. The rotary shaft extends with its long axis oriented along the axis R through a feedthrough 21 disposed in the center of the base portion 3. The feedthrough 21 serves as a mount for the coupling means 19 and comprises an annular sealing member 22 for a leak tight connection between the base portion 3 of the cup 2 and the coupling means 19 enabling rotation of the shaft by an external actuator without leakage of fluid material from the paint cup 2. The sealing member 22 can comprise a rubber gasket that can be affixed to the base portion 3, as part of the feedthrough 21, mechanically for example by clamping means or a groove or by an adhesive. The coupling portion 20 of the coupling means 19 is located outside of the paint cup 2. It is shaped and configured to be engaged by a matching connecting part of an actuator 30 configured to drive the rotatable mixing element 17 (cf. also FIG. 2). In the depicted embodiment the coupling portion 20 has a polygonal (e.g. square) cross-section which fits into a recess of matching shape and dimensions of a connecting sleeve 32 at the end of the drive shaft of an external actuator 30. The rotatable mixing element 17 is thus operatively connected to the actuator 30 via the coupling means 19 and may be actuated to rotate around rotation axis R when operating the external actuator 30.
[0048] The paint cup shown in FIG. 1 has a ring-shaped support 23 formed at the bottom of the base portion 3 to provide a stand by which the cup may rest on a ground. The ring-shaped support 23 may suspend the base portion 3 of the cup 2 at a distance above the ground and thereby form a recess 24 at the bottom of the cup 2. The coupling means 19 extending through the feedthrough 21 can be situated within the recess 24. The paint mixing container 1 shown in FIG. 1 comprises further a ventilation valve 25 disposed at a peripheral portion of the base portion within the recess 24. The ventilation valve 25 is typically closed when the paint mixing container is in its upright position resting with its ring-shaped support 23 on a ground, for example for adding paint components to the cup 2 or mixing the same, and is opened when using the container 1 in an upside-down orientation (i.e. with the base portion facing upward and the lid with the outlet at the bottom) to feed paint under the action of gravity to an applicator system such as a spray gun coupled to the outlet 13.
[0049] FIG. 2 shows a variant to the paint mixing container according to FIG. 1. In this variant the lid 8 is configured as a snap fit lid rather than as a threaded lid as shown in FIG. 1. The snap fit lid 8 can be removably installed to close the opening 6 of the paint cup 2 by pressing its ring-shaped portion 9 onto the matching rim formed by the upper end of the sidewalls 4 of the cup 2. The ring-shaped portion 9 is typically somewhat elastic such that it can engage the matching rim formed by the upper end of the sidewalls 4 of the cup 2 when force is applied to form a tight connection. Herein, the ring-shaped portion 9 may have a substantially U-shaped cross-section with an outer leg 36 and an inner leg 11 connected by a middle leg 37. The outer leg 36 and the inner leg 11 contact the outer surface or the interior surface of the rim formed by the upper end of the sidewalls 4 of the cup 2, respectively, when the lid 8 is installed to seal the paint cup 2. The outer leg 36 can have a retention element 38, for example a protrusion or bend portion, to retain the lid in its installed position by grasping the rim formed by the upper end of the sidewalls 4 of the cup 2. The lid 8 furthermore has a tab 39 formed at the ring-shaped portion 9 to extend radially outward therefrom. The tab 39 facilitates removing the lid 8 again from the paint cup 2 by pulling the lid 8 via the tab 39 upwards away from the cup 2.
[0050] In the embodiment shown in FIG. 2, the ventilation valve 25 is moreover provided on the lid 8 rather than at the base portion 3 of the paint cup 2. A hollow tube 40 may be connected to the valve 25 and extend into the receptacle volume 5 of the paint cup 2. The position and length of the tube 40 is selected such that the tube does not interfere with the rotatable mixing means 17 and that its free end is above typical fill levels when the container is used in an upside-down orientation. Thus, an efficient pressure equilibration without the risk of paint leakage can be achieved when the paint container 1 is used in an upside-down configuration.
[0051] FIG. 3 illustrates a paint mixing container 1 according to FIG. 1 as discussed above with paint components P provided in the receptacle volume 5 and lid 8 installed to close the opening 6 of the cup mounted to an exemplary paint mixing apparatus 26 according to the present invention. The paint mixing apparatus 26 comprises a port 27 to accommodate the paint mixing container 1. The port 27 can in particular have a basically complementary shape to the container 1 or a portion thereof to form a seat to which the container may be introduced for example from the top. For the sake of a clearer illustration the container and the portions of the apparatus 26 that receive and couple to the container are shown in cross-section in FIG. 3. As depicted, the port may be configured such that the container when properly installed rests in a basically upright orientation. The port may comprise an annular groove 28, which matches with the ring-shaped support 23 such that the latter fits inside the groove 28. The port 27 may optionally comprise further means to fix or retain the container during the mixing operation. For example, resilient or spring biased retention elements 29 can be provided on the port structure, e.g. laterally on the inside thereof, to exert a holding force on the container installed in the port 27.
[0052] The paint mixing apparatus 26 furthermore comprises an actuator 30 configured to drive the rotatable mixing element. The actuator 30 may in particular comprise an electrical or pneumatic drive or motor disposed in a housing 31. A drive shaft which is oriented with its long axis along the axis R is connected to the drive. At the free end of the drive shaft the actuator 30 comprises a connecting part 32 having a shape and dimensions configured to releasably engage the coupling portion 20 of the coupling means of the container 1 as described above. In the depicted configuration the connecting part 32 is disposed at the bottom of the port 27 to operatively couple the actuator 30 to the rotatable mixing element 17 inside the paint cup 2 via the coupling means 19 which extend through the feedthrough 21 at the base portion of the paint cup 2. Operation of the actuator 30 thus rotates the drive shaft, which by means of the afore-mentioned coupling ultimately drives the rotatable mixing element 17 disposed in the receptacle volume 5 of the container 1 around rotational axis R to thereby mix the contained paint components P. The paint mixing apparatus 26 may comprise control means 33 such as adjustment knobs to set the rotational speed and the duration of the mixing process. A display 34 can be provided on the housing 31 to provide status information and/or to facilitate user interaction. Support feet 35 for example made of a vibration-dampening material can be provided at the bottom of the apparatus 26. The paint mixing apparatus 26 may likewise be used with a paint mixing container as depicted in FIG. 2.
[0053] FIG. 4 shows a cross-sectional view of another exemplary paint mixing container 1 in accordance with the present invention, with the lid 8 in installed position on the cup 2. The embodiment shown in FIG. 4 corresponds to the container described above with reference to FIG. 1, however, in this case the rotatable propeller-type mixing element 17 is mounted to the lid 8 rather than to the base portion 3 of the cup 2. More specifically, the rotatable propeller-type mixing element 17 is mounted to the lid 8 via coupling means 19, which comprise a shaft that extends through a feedthrough 21 with sealing members 22 provided in the center at the top of the lid 8. In the depicted configuration the tubular outlet 13 with the external thread 14 for coupling to an external applicator device is disposed laterally on the conical wall portion 12, close to the top of the lid 8. The filter 15 may be provided at or within the outlet 13 for avoiding interference with the rotation mechanism.
[0054] FIG. 5 represents a cross-sectional schematic view of another exemplary embodiment of a paint mixing container 1 according to the present invention, wherein the rotatable propeller-type mixing element 17 is mounted to the lid 8
[0055] analogous to the embodiment of FIG. 4. However, in case of the embodiment shown in FIG. 5 the paint cup 2 comprises an outer support cup 41 and an interior liner 42. Both the support cup 41 and the liner 42 have a truncated conical shape, which is symmetric with respect to the depicted central rotation axis R, and have a flat circular base portion 3, and sidewall portions 4 extending therefrom to define an interior volume 5. The end opposite to the base portion is open. The liner 42 has slightly smaller dimensions than the support cup 41 such that it can be inserted into the support cup 41, forming a nested configuration. The liner 42 has a circumferential flange 43 at its open end 6, which rests on the upper rim 44 of the support cup 41 in the nested configuration. The lid 8 is has a shape and dimensions such that it fits on the liner 42 to close its opening 6. For example, the bottom end of the lid 8 can have a ring-shaped portion 9 having a basically L-shaped cross-section which rests on the flange 43 when the lid is installed on the liner 42. A leak-tight connection of the assembly of the lid 8, the liner 41 and the support cup 42 can be achieved by means of a sleeve nut-like connector 45, having a ring shape with a basically L-shaped cross-section, provided with an internal thread 46, which matches with an external thread 47 provided on the outside of the rim 44 of the support cup 41. By tightening the connector 45 via the thread connection on the support cup 41 a compressive force is exerted by which the ring-shaped portion 9 of the lid 8, the flange 9 of the liner 42 and the rim 44 of the support cup are pressed together to form a leak tight connection. In the embodiment according to FIG. 5 the interior volume of the liner 42 forms the receptacle volume 5 wherein the paint components to be mixed are received. The receptacle volume 5 can for example have a volume in the range of 100 mL to 1000 mL, such as about 300 mL, 600 mL or 900 mL. The rotatable mixing element 17 is disposed in the receptacle volume 5 being mounted to the lid 8 via coupling means 19, which comprise a shaft that extends through a feedthrough 21 with sealing members 22 provided in the center at the top of the lid 8. The rotatable mixing element depicted in FIG. 5 has mixing blades in a form of C-shaped brackets at the free end of the shaft. Various other configurations of the rotatable mixing element can though be used as described herein.
[0056] In case of a support-liner assembly as for example illustrated in FIG. 5 the liner 42 and lid 8 would typically be disposable, while the support cup 41 and the connector 45 can be used recurrently as they do not come into contact with the paint components. The liner 42 may in particular be made of a flexible material, for example an elastic plastic material, that allows for an adaptation when subjected to a pressure differential upon withdrawal of mixed paint from the container. The support cup 41 and the connector 45 as well as the lid are typically made on the contrary from a rigid material. The lid 8 can be configured to have an outlet 13 for the paint analogous to the embodiment shown in FIG. 4. Alternatively, the lid 8 with the mounted rotatable mixing means 17 can be replaced by another lid 8 having an outlet 13 for the paint after mixing of the paint components for subsequent use with an applicator device such as a spray gun.
[0057] The paint mixing containers 1 shown in FIGS. 4 and 5 may be used in an analogous manner as described above for FIG. 1 with the difference that the actuator then couples to the coupling means 19 from the top of the container 1.
[0058] As already mentioned above, the rotatable mixing element 17 used in the paint mixing containers according to the present invention such as those shown in FIGS. 1,2, 4 and 5 can have various different configurations. This includes all kinds of shapes and geometries that are common in the art for mixing or stirring paints.
[0059] FIGS. 6A to 6E illustrate some non-limiting exemplary configurations of the rotatable mixing element that can be used according to the present invention. As shown in FIGS. 6A and 6B the rotatable mixing element 17 can for example have a disc or ring-shaped element at the free end of the rotatable shaft. Arcuate, tortuous or spiral-shaped members may extend from the shaft to the disc or ring-shaped element at the free end of the rotatable shaft, such as three tortuous members in case of FIG. 6A or two arcuate members in case of FIG. 6B. FIG. 6C illustrates another configuration, wherein the mixing element comprises a plurality (such as two) C-shaped brackets extending radially at the free end of the shaft to each enclose a rectangular opening. FIG. 6D illustrates further a propeller-type configuration, wherein three spoon-like mixing blades, which are inclined under an angle with respect to the rotation direction, extend radially from the rotation shaft and are arranged symmetrically thereto. The shape, arrangement and number of mixing blades in such configurations can be varied widely. For example, FIG. 6E illustrates another configuration, wherein a plurality (such as six) of in this case inclined rectangular mixing blades extend radially from the rotation shaft in a symmetric manner. As shown in FIGS. 6D and 6E the mixing blades can be solid or have one or more openings.
[0060] The paint mixing containers 1 as shown in FIGS. 1, 2 and 4 and 5 and the components thereof such as the cup 2, the lid 8, the rotatable mixing element 17 and the coupling means 19 can in particular be made from a plastic material, preferably a recyclable or biodegradable plastic material, such as any of the materials mentioned previously, for example by injection molding. The sealing member(s) 22 are typically made of an elastic abrasion resistant material such as rubber and can be incorporated in-situ during formation of the plastic body to which they shall be attached (i.e. the cup 2 or the lid 8) or be affixed after the plastic body has been formed. The illustrated exemplary paint mixing containers may in particular be disposable.
[0061] Although exemplary specific variants may have been described in the present disclosure above for illustrative purposes, it is to be understood that the present invention is to be construed over the entire scope of the appended claims including any variations thereof under the doctrine of equivalents.
