Apparatus for mixing liquid products to prepare coloring substances for paints and the like

Abstract: The present invention relates to an apparatus for mixing liquid products, in particular to prepare coloring substances for paints and the like. The apparatus comprises a base, supporting a substantially horizontal table, which supports, on the top face thereof, a plurality of vessels for the liquid products to be mixed. Inside each vessel is applied a stirring element which project, by its driving end portion, from the related vessel. The apparatus further comprises a coupling element for coupling the driving end portions of the several stirring elements to driving means, which can be actuated for simultaneously driving the stirring elements.

Description: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for mixing liquid products, in particular to prepare coloring substances for paints and the like. Such apparatuses are for example disclosed in DE-A-2 951 731 and in EP-A-0 065 498. As is known, one of the most important operations for preparing coloring substances for paints or the like, is that of properly mixing the coloring substances. In order to perform this operation, there are at present used mixing apparatus including stirring elements, arranged inside the vessels into which is introduced the coloring substance to be mixed. These prior apparatus have the drawback that they subject the coloring substances to a comparatively strong stirring force, thereby altering the pigment or dye materials of the coloring substances. This problem is very important in this field since, a possible alteration of the coloring substances can cause a consequent alteration of the color hue and/or a quick degradation of the coloring substance. SUMMARY OF THE INVENTION Accordingly, the aim of the present invention is to overcome the above mentioned problem, by providing an apparatus for mixing liquid products, in particular coloring substances for paints or the like, which does not cause any alterations of the pigment or dye materials contained in these products, in which the mixing apparatus has a comparatively simple construction and is very safe and reliable in operation. Within the scope of the above mentioned aim, a further object of the present invention is to provide such a mixing apparatus suitable to simultaneously mix several coloring substances contained in different related vessels, so as to assure a very homogeneous mixing of the contents of the mentioned vessels. Another object of the present invention is to provide such a mixing apparatus which is very competitive with respect to prior like commercially available apparatus. According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a mixing apparatus as defined in claim 1. BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of the apparatus according to the invention which is illustrated, by way of an indicative, but not limitative, example, in the figures of the accompanying drawings, where: Figure 1 is a schematic view illustrating a top plan view of the apparatus according to the present invention; and Figure 2 is an enlarged cross sectional view of the apparatus according to the present invention substantially taken along the section line II-II of Figure 1. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the number references of the above mentioned figures, the mixing apparatus according to the present invention, which has been generally indicated by the reference number 1, comprises an apparatus base or framework 2, supporting a substantially horizontal table 3 and which, in turn, supports, on the top face or surface thereof, a plurality of vessels 4, 5, having preferably a substantially cylindrical configuration and vertical axis, provided for holding therein liquid products to be mixed. Inside each vessel 4, 5 is arranged a stirring element 6 which projects, by a driving end portion 7 thereof, from the bottom of the related vessel and which is coupled, by a coupling element 9, to driving means, which can be controllably actuated in order to drive the several stirring elements 6 arranged in their respective vessels 4, 5. More specifically, each stirring element 6 comprises a blade which is connected to a shaft 8 which is rotatably supported about its rotation axis which substantially coincides with the axis of the vessel in which it is arranged. The bottom end portion of the shaft 8 projects at the bottom from the related vessel 4, 5 and comprises a crankshaft 7. The free end portion 7a of each crankshaft 7, which is substantially parallel to and spaced from that portion of the shaft 8 which extends inside the vessel 4, 5, is pivoted to the coupling element 9. The latter is suitably constituted by a star connecting rod, which is turned toward the top surface of the table 3 and being coupled to the driving means by a crank 10 which can turn about an axis spaced from the center of the star connecting rod. The driving means preferably comprise an electric motor-reducing unit 11, which is supported from the inside of the base 2 and has the vertical output shaft 12 thereof which is connected to the crank 10 which, in turn, is connected, by a pin 21, parallel to and spaced from the shaft 12 to the connecting rod 9, by the interposition of a bearing 22. As shown, for size considerations, the pin 21 is connected to a plate 13, which is rigid with the star connection rod 9 and is raised from the latter by means of columns 14. The output shaft 12 of the unit 11 is connected to the connecting rod 10 by unidirectional driving means, which advantageously comprise a free wheel 15. The latter is mounted about the output shaft 12 and is housed inside a suitable recess defined in the crank 10. The table 3 is supported by the base 2 through bearings 16, so as to turn about an axis which coincides with the axis of the shaft 12, i.e. with the turning axis of the crank 10. The star connecting rod 9 is coupled to the crankshafts 7, which project at the bottom from the related vessels 4, 5 by end portions, or by portions nearer to the center so as to allow to arrange, above the table 3, a high number of vessels 5 having their centers on two concentrical circumferences. Near the periphery of the table 3 there are arranged metering-dispensing devices 17, for example plunger devices of a known type, each being connected to a respective vessel through a duct 18 so that the coloring substance held in the vessels 4 and 5 can be supplied, in a metered manner, depending on requirements. The mixing apparatus according to the present invention operates as follows. The coloring substances to be mixed are introduced into the vessels 4 and 5. Then, the motor reducing unit 11 is actuated so as to rotate the crank 10 and, accordingly, the star connecting rod 9 about the axis of the output shaft 12 of said unit. Thus, the connecting rod will define, by the center thereof, a circumference about the axis of the output shaft 12. This motion of the star connecting rod will simultaneously operate all of the crankshafts 7 and, accordingly, all the mixing blades 6 provided in the related vessels 4 and 5. After having achieved a desired mixing degree, the unit 11 is stopped and, by exploiting the rotary capability of the table 3 about the axis of the output shaft 12, owing to the provision of the bearing 16, it will be possible to bring one or more metering-delivering devices 17 to a related vessel, arranged under the table 3 and provided for receiving a metered amount of the coloring substances held in the vessels. In particular, the table 3 can be rotated about the axis of the output shaft 12 either manually, or by an auxiliary motor, of any known types and not shown for simplicity, so as to cause the free wheel 15 to idly rotate with respect to the output shaft 12, so as not to further mix the coloring substances held in the vessels 4 and 5. From the above disclosure and from an observation of the figures of the accompanying drawings, it should be apparent that the invention fully achieves the intended aim and objects. In particular, the fact is to be pointed out that an apparatus has been provided which is adapted to simultaneously mix several liquid products, in particular coloring substances for paints and the like, held in several vessels, thereby providing a substantially homogeneous mixing inside said vessels.

Claims: An apparatus (1) for mixing liquid products, in particular for preparing coloring substances for paints and the like, comprising a base (2) supporting a horizontal table (3), which supports, on a top face thereof, a plurality of vessels (4, 5) for the liquid products to be mixed, inside each said vessel (4, 5) a stirring element (6) being arranged, which projects, by a driving end portion (7) thereof, from said vessel (4, 5), a coupling element (9) being moreover provided for coupling all of the driving end portions (7) of said stirring elements (6) to driving means (11) which can be controllably actuated to drive said stirring elements (6), said driving end portions (7) comprising crankshafts rotatably supported about a vertical axis by a related vessel (4, 5) and pivoted to said coupling element (9), characterized in that said coupling element comprises a star connecting rod, arranged on the table (3) and pivoted at the center of the connecting rod (9) to a crank (10), which can be rotatively driven by the driving means (11) about a vertical axis spaced from the center of said star connecting rod. An apparatus according to Claim 1, characterized in that said driving means (11) comprise a motor reducing unit (11), supported by said base (2) under said table (3) and coupled, by an output shaft (12) of the motor reducing unit (11), to said crank (10). An apparatus according to claim 2, characterized in that said output shaft (12) is coupled to said crank (10) through unidirectional transmission means (15). An apparatus according to Claim 3, characterized in that said unidirectional transmission means (15) comprise a free wheel, mounted about the output shaft (12) and coupled inside said crank (10). An apparatus according to one or more of the preceding claims, characterized in that said base (2) rotatably supports said table (3) about a vertical axis coinciding with the rotary axis of said crank (10). An apparatus according to one or more of the preceding claims, characterized in that said stirring elements (6) comprise each a blade, coupled to that portion of the related crankshaft (7) which vertically extends inside the related vessels (4, 5). An apparatus according to one or more of the preceding claims, characterized in that said vessels (4, 5) have a cylindrical configuration and that said crankshafts (7) are arranged with the rotary axes thereof coinciding with the axis of the related vessel. An apparatus according to one or more of the preceding claims, characterized in that each said vessel (4, 5) is coupled to a metering-delivering device (17) mounted at a peripheral portion of said table (3).

Inventors: NERI GIUSEPPE C O FAST S P A, NERI, GIUSEPPE, C/O FAST S.P.A.
Applicants: FAST SPA, FAST S.P.A.
Application year: 1995
Main classification: B01F13
IPC codes: B44D3, B01F13