A PAINT TONING MACHINE

Abstract: A paint toning machine comprising a plurality of colour paste containers (1); a pump (2) for each paste container (1) for pumping colour paste (3) for the dispensing and circulation thereof; and a dispensing valve (11) for each pump (2) for dispensing a desired amount of colour paste. For the elimination of the problems caused by leaks occurring in the dispensing valve and the pipe connections thereof, the dispensing valve (11) according to the invention is arranged in the paste container (1) in the vicinity of a bottom (4) thereof essentially below the surface of the colour paste (3) contained in the container.

Description: A paint toning machine This invention relates to a paint toning m chine comprising a plurality of colour paste co tainers, a pump for each paste container for pumpi colour paste for the dispensing and circulation ther of, and a dispensing valve attached to each pump f dispensing a desired amount of colour paste. A paint toning machine of the above type i known e.g. from Australian Patent Specification 162 212. Therein the dispensing valves are positione on the circumference of a semicircle so that the de sired dispensing valve can be turned above a paint po containing paint to be toned for dispensing. Thus th dispensing valve is positioned relatively far from th dispensing pump positioned in the vicinity of the col our paste container, wherefore it has to be provide with rather long hose connections for a colour past dispensing conduit and a return conduit. The colou paste normally circulates in the dispensing and retur conduits so that it is mixed and stays homogeneous and the dispensing is carried out by controlling th dispensing valve, whereby the colour paste can b passed from the dispensing conduit to the dispensin nozzle. A problem with this kind of arrangement, how ever, is that the couplings of the hose connections t the dispensing valves as well as the structure of th dispensing valve itself are liable to leakage, espe cially in cases where the colour paste is solvent-di luted, whereby it penetrates extremely easily eve through minor gaps. Such leaks may result in operatio nal disturbances in the dispensing valve, and they ma even cause the colour paste to be dried either in th valve or in the dispensing and return conduits at tached thereto so that the conduits may clog. The object of the present invention is to elim inate the problems possibly caused by such leaks. paint toning machine according to the invention b means of which this object can be achieved is charac terized in that the dispensing valve is arranged i the paste container in the vicinity of the botto thereof essentially below the surface of the colou paste contained in the container. By immersing the dispensing valve in the colou paste, problems caused by possible leaks in the valv can be fully eliminated. The immersion of the valve i the colour paste is preferably carried out in such manner that a drive shaft of the dispensing valve pro jects outside the paste container preferably through gas-tight through hole formed in the cover of th paste container. In this way, the operating means o the dispensing valve can be positioned outside th paste container, so that it can be completely conven tional in structure. In a preferred embodiment of the invention, th dispensing valve comprises a valve spindle having first conical surface for closing a paste circulatio conduit and a second conical surface for closing paste dispensing conduit, whereby a counter surfac for the first conical surface is formed in a floo positioned above the bottom of the paste container and a counter surface for the second conical surfac of the spindle is formed in the bottom of the past container, whereby a paste feeding conduit connecte to the dispensing valve is positioned between the bot tom and the floor. In this way the dispensing valv and the paste dispensing and circulation conduits at tached thereto can be formed by means of the past container and other structural parts which are simpl and inexpensive to manufacture. The drive shaft of th dispensing valve is vertical and so positioned that goes through the floor via the paste circulating co duit. Thus the dispensing valve merely requires short to-and-fro movement for the operation thereo and this can be effected simply by means of e.g. magnetic operating means provided with a retu spring. In the following the paint toning machine a cording to the invention will be described in more d tail with reference to the attached drawing, wherein Figure 1 shows a cross-section of one pas container of the paint toning machine according to t invention, and Figure 2 shows a section of the paste co tainer of Figure 1 along the line A-A shown in t same figure. Figure 1 shows one of a plurality of paste co tainers comprised in the paint toning machine accor ing to the invention; this container is indicated wit the reference numeral 1. A gear-type pump 2 is i mersed in the colour paste contained in the paste con tainer, and a drive shaft 5 of the pump goes through cover 6 of the container through a gas-tight throug hole 7. The cover 6 of the container is arranged o the container 1 as tightly as possible. Suction an pressure conduits 8 and 9 for the pump 2 are formed b means of a floor 10 positioned above a container bot tom 4. The floor 10 also forms a structural part of dispensing valve 11 attached to the colour paste con tainer 1 in such a manner that it forms a counter sur face for an upper conical surface 13 of a spindle 1 of the dispensing valve 11. The spindle 12 of th valve 11 also comprises a lower conical surface 2 which closes a colour paste dispensing conduit 1 going through the bottom 4 of the paste container when the spindle 12 of the dispensing valve is in the position shown in Figure 1. Thereby the upper conical surface 13 of the valve is not positioned against the counter surface thereof so that it leaves open the es- sentially vertical colour paste circulation conduit 14 going through the floor 10. The colour paste 3 thereby circulates in the container 1 along a path shown b the dark arrows when the pump 2 is on. Colour paste is thereby sucked from the container 1 through the suc- tion conduit 8 of the pump 2 and it enters the circu¬ lation conduit 14 through the feeding conduit 9 past the conical surface 13 of the spindle 12 of the dis¬ pensing valve 11, and then returns to the container 1. This circulation keeps the colour paste homogeneous in the container. A drive shaft 16 of the dispensing valve 11 extends from the spindle 12 of the valve through the circulation conduit 14 and further through the cover 6 of the colour paste container 1 through a gas-tight through hole 21 to a valve operating means 15, the operating means comprising a magnet coil 23 and a return spring 24. When the magnet coil 23 is magnetized, the drive shaft 16 rises upwards so that the conical surface 13 of the valve spindle 12 closes the colour paste circulation conduit 14, and the pres- sure conduit 9 from the pump 2 joins the colour paste dispensing conduit 17, going past the conical surface 22 of the valve spindle 12 and further to a colour paste dispensing nozzle (not shown). When the current to the magnet coil 23 is switched off, the return spring 24 returns the drive shaft 16 to the lower position, thus closing the colour paste dispensing conduit 17 and opening the colour paste circulation conduit 14. Figure 2 shows a section of the colour paste container of Figure 1 along the line A-A shown in Figure 1. It appears from Figure 2 that the pump 2 a gear-type pump comprising a primary gearwheel 18 a tached to the drive shaft 5 and a secondary gear whe 20 attached to a support shaft 19. As is to be seen i Figure 2, the colour paste container 1 is essentiall round in shape with the exception of a projectio formed for the dispensing valve. The paint toning machine according to the in vention and especially the dispensing valve immerse in the colour paste contained in the paste containe have been described above only by way of example b means of a specific embodiment. It is to be understoo that the idea according to the invention concernin the immersion of the dispensing valve in the colou paste could also be realized with a separate dis pensing valve of a more conventional structure, where by the operating means thereof, of course, have to b suitable for such immersion. As the dispensing valv and the pipe connections thereof would be wholly i mersed in the colour paste in this kind of applica tions, too, the same advantages as described above ca be achieved also in this case concerning leaks in th dispensing valve or its connections. Of course, othe modifications, such as the leading of the drive shaf of the dispensing valve either through the side o through the bottom of the container, and the leadin of the dispensing conduit through the side of the con tainer, are also possible, without, however, deviatin from the scope of protection defined in the attache claims.

Claims: Claims : 1. A paint toning machine comprising - a plurality of colour paste containers (1), - a pump (2) for each paste container (1) for pumping colour paste (3) for the dispensing and circu¬ lation thereof, and - a dispensing valve (11) attached to each pump (2) for dispensing a desired amount of colour paste, c h a r a c t e r i z e d in that the dispensing valve (11) is arranged in the paste container (1) in the vicinity of a bottom (4) thereof essentially below the surface of the colour paste (3) contained in the container. 2. A paint toning machine according to claim 1, c h a r a c t e r i z e d in that the dispensing valve (11) comprises a drive shaft (16) which projects outside the paste container (1) through a gas-tight through hole (21). 3. A paint toning machine according to claim 2, c h a r a c t e r i z e d in that the dispensing valve (16) comprises a valve spindle (12) having a first conical surface (13) for closing a paste circu¬ lating conduit (14) and a second conical surface (22) for closing a paste dispensing conduit (17); that a counter surface for the first conical surface (13) of the spindle (12) is formed in a floor (10) positioned above the paste container bottom (4) , and counter sur¬ face for the second conical surface (22) of the spindle is formed in the paste container bottom (4), a paste feeding conduit (9) to the dispensing valve (11) being positioned between the bottom (4) and the floor (10). 4. A paint toning machine according to claim 3, c h a r a c t e r i z e d in that the drive shaft (16) of the valve (11) goes through the floor (10) v the paste circulating conduit (14).

Inventors: AIRAKSINEN PENTTI, AIRAKSINEN, PENTTI
Applicants: CIMCORP OY
Application year: 1988
Main classification: B44D3
IPC codes: B44D3