Device for mixing of paints and toners

Abstract

A device for mixing cans of different sizes for paints, said device comprising a pedestal and a frame rotatably mounted on said frame around a first axis. The frame is supporting a disc for a can to be mixed rotatably around a second axis perpendicular to said first axis. The device is provided with driving means for rotating said frame and said disc around said axis. A transmission means is coupled to rotate said disc selectively with at least two different speeds, a lower speed for a larger can and a higher speed for a smaller can.

Description

The subject of the present invention is a device for mixing cans of different sizes for paint in particular paints and toners, which device comprises a pedestal a frame mounted on said pedestal rotatably around a first axis, a first pulley or equivalent fastened to said frame for rotation thereof, a disc supported by said frame for fastening a can of paint to said frame, said disc being rotatably mounted around a second axis extending transversely with respect to said first axis, a second pulley or equivalent fastened to said pedestal coaxially with said first pulley and power means connected to said first pulley for rotation thereof, said second pulley being connected to said disc by driving means for rotation of said disc upon rotation of said first pulley.

For mixing paints and their toners, a method and equipment are previously known in which the mixing can is vibrated to and fro. In retail stores for paints, in which the paints sold are mixed in accordance with the customer's choice out of basic tones and various toners, devices are in use to which the paint can is fastened after addition of the toners and which vibrate the paint can to and fro. In these devices it is possible to detach the paint can during mixing, to turn it upside down and to repeat the mixing in order that the mixing should take place uniformly. A drawback with these known devices is the vibration, which causes disturbing noise in the air of the space of location of the device and, moreover, the vibration is transmitted along the building skeleton as a disturbing noise into the surrounding rooms. Another drawback is the length of the mixing period, which is about 3 to 5 min. with the above mixing device for paints. Another drawback is that vibrating of the mixing can to and fro causes high strains on the can, and when using known devices, ruptures of the paint can have taken place when the seams of the cans have been broken. Even though high accelerations of the mixing can have been used in the vibrator devices, perfectly satisfactory mixing results have not been obtained in all cases.

From the German patent publication No. 1,080,072, a mixing device is previously known by means of which the mixing can is rotated at the same time around two axis which are perpendicular to each other. Said patent publication contains no mentioning of mixing of paints and their toners. To conclude from the embodiments presented in the patent publication, the device is intended to be a laboratory appliance, and as such it is not suitable for mixing paints and their toners.

A mixing method is also earlier known according to which a mixing container, such as paint can, having a substantially cylindrical or conical jacket, is rotated around the center axis of its jacket at an angular speed that is at least three, preferably four times as high as the angular speed of the rotation taking place around a second transverse axis, the number of revolutions of the rotation around the latter axis being at least 120 rpm, preferably 160 to 180 rpm. In said earlier known method, the purpose has been that all sizes of paint cans (0.25 litres to 10 litres) are during mixing rotated with the same number of revolutions. The consequence from this has been that the power of the motor operating the device has to be dimensioned in accordance with the largest size (10 litres) of paint can and, therefore, as relatively high power. In tests carried out it has been noticed that, for a satisfactory mixing result within a desired short, preferably constant, mixing duration, larger can sizes or the largest can size (10 litres) permit the use of lower speeds of rotation than do the smaller can sizes. This observation has been one of the starting points of the present invention.

A purpose of the present invention is to produce a mixing device of simple construction and use and reliable operation, in which motor powers smaller than before are sufficient and which causes strains lower than before on the mixing container so that earlier obvious risk of rupture of the largest can size should not appear. This purpose is obtained by means of a device which is characterized by transmission means coupled between said disc and said driving means, said disc being axially displaceably supported by said frame, said transmission means changing the number of revolutions of said disc around said second axis when said disc is displaced axially, so that when said disc is at a position corresponding to the largest paint can size, the number of revolutions is lower than when said disc is in a position corresponding to a smaller paint can size.

Below, the invention will be described in detail with reference to an embodiment of the invention, shown in the figures of the drawing, to which embodiment the invention is by no means restricted.

FIG. 1 shows a mixing device as a partial cross-section as viewed from the side and with the largest paint can size being fastened to the device,

FIG. 2 shows the same as a front view,

FIG. 3 shows an axial section of the transmission system arranged in connection with the rotation disc for paint can in the position corresponding to the largest paint can size, and

FIG. 4 shows the same transmission system as FIG. 3 in a position corresponding to a smaller paint can size.

The equipment shown in the drawings substantially comprises a support pedestal 1 and a frame 2 rotably mounted thereon. The pedestal 1 comprises a horizontal part 3, which supports an electric motor 4, and a vertical part 5. At the top of part 5 of the pedestal, a vertically positioned disc 6, shaped as a pulley, has been fastened rigidly, and to this disc a horizontal bearing bushing 7 has been fastened centrally. In the bearing bushing 7, by means of bearings 8, a shaft 9 has been mounted rotably, which shaft has been rigidly and centrally fastened to a vertically positioned support disc 10, shaped as a pulley and belonging to the frame 2. The support disc by means of a transversal beam 10a supports a bearing housing 11, whose construction will be described more closely below. In the bearing housing, a vertical shaft 12 is rotably mounted, which shaft is rigidly fastened to a horizontal rotation table 13, on which the mixing container 14, such as a paint can, is intended to be positioned.

On the support disc 10, shaped as a pulley and belonging to the frame 2, on the side opposite to the bearing housing 11, supports 16 have been fastened, on which supports pulleys 17 and 18, respectively, have been mounted as freely rotating, by means of shafts 19, 20 carried by the supports. The shafts are placed in a plane perpendicular to the shaft 9. Moreover, a third pulley 21 has been fastened to the support disc 10 by means of a support 15, which pulley is mounted as freely rotating on the said support by means of a shaft 22. This shaft is likewise placed in a plane perpendicular to the shaft 9, but its direction forms an angle with the direction of the shafts 19, 20. For the pulley 21, a corresponding opening 23 has been formed in the support disc 10.

In the bearing housing 11, a pulley 24 of a larger diameter and positioned higher has been mounted rotably, and coaxially with it a pulley 25 of a smaller diameter and positioned lower, as will be described more closely below.

The arrangement is now such that an endless belt 26 can be conducted around the pulley 6, the pulley 17 operating as the turning disc, and around the pulley 24 of the bearing housing 11 and from there further around the pulley 21 and the other pulley 25 of the bearing housing 11 and finally over the pulley 18 operating as the turning disc back to the pulley 6. A separate endless belt 28 has been placed around the pulley 10 belonging to the frame and the pulley 27 of the electric motor 4.

When the electric motor goes round, the belt 28 under these circumstances rotates the pulley 10 and all the components fastened to same, such as the pulleys 17, 18 and 21 as well as the bearing housing 11 and the rotation table 13, around the center axis B--B of the shaft 9. Since the pulley 6 is stationary a tractive force is produced in the belt 26 when the frame 2 rotates, which force causes rotation of the pulleys 24 and 25 and, consequently, rotation of the rotation table 13 around the center axis A--A of the bearing housing 11.

At the support disc 10 of the frame, two projections 29 have been fastened which, at their outer ends, support two mutually parallel slide rails 30, on which slide sleeves 31 have been placed. The slide sleeves are connected to each other by means of a beam 32, at whose middle a bearing 33 has been provided, at which one, freely rotating fastening disc 34 has been mounted. Due to the slide rails 30 and the sleeves 31, the fastening disc 34 can be shifted in the direction of the axis A--A so as to secure the can against the rotation disc 13. The position of the rotation disc 13 is preferably selected so that the center of gravity of the mixing container lies as close as possible to the intersection point C of the axis A--A and B--B. The construction of the shifting and locking device for the sleeves 31 and the beam 32 between them has not been shown. By changing the mutual relationship between the diameters of the pulleys 6 and 24, 25, the ratio of the rates of rotation around the axis A--A and B--B can be selected as suitable.

Below, with particular reference to FIGS. 3 and 4, a detailed description will be given of the transmission system, by means of which the movement of the belt 26 is transferred to the rotation disc 13 as a movement of rotation around the axis A--A.

The bearing housing 11 has bearings 36, in which the internal bushing 35 has been mounted. The shaft 12 of the rotation disc 13 runs through the bushing 35. The pulley 24 has been mounted separately on the bushing 35 by means of a bearing 36a. Also, the other pulley 25 has been mounted at the opposite end of the bushing 35 by means of a separate bearing 37. In accordance with FIG. 3, the rotation disc 13 has been shifted to the position corresponding to the largest size of paint can, and in this case the rotation disc 13 has been coupled by means of the peg 38 therein so as to operate the pulley 24, whereby, of course, the shaft 12 is disconnected from the other pulley 25. In accordance with FIG. 3, the pulley 24 has a hole 39, into which the peg 38 is inserted when the rotation disc 13 is pressed against the end of the bushing 35. To the bushing 35, a transversal peg 40 has been fastened which extends through an axial groove 41 in the shaft 12. The groove 41 extends towards the rotation disc 13 far enough so that the rotation disc 13 is permitted to be pressed to the position in accordance with FIG. 3.

When it is desired to alter the size of paint can and/or the number of revolutions of the rotation around the axis A--A, the rotation disc 13 is raised from the position shown in FIG. 3, whereby the shaft 12 rises while the peg 40 moves in relation to the groove 41. When the rotation disc has been raised to the upper position, the rotation disc is turned slightly so that the peg 40 enters the extended groove 42, constituting an extension of the groove 41, whereby the rotation disc 13 is locked in connection with the bushing 35. At the same time the locking lever 43, which was previously inside the shaft in a pivoted position, can pivot around its shaft 44 by the effect of its spring 45 to the position in accordance with FIG. 4, in which position the locking lever 43 is pressed into the grooves 46 at the end of the bushing 35 and the pulley 25. In this way the pulley 25, the bushing 35, the shaft 12, and the rotation disc 13 become firmly connected with each other, and the rotation disc 13 becomes operated by the smaller pulley 25 while the other pulley 24 rotates freely. The shaft 44 of the locking lever 43 as well as one end of its spring 45 are fastened to a component 47 inside the shaft 12, which component is, on the other hand, fastened to the bushing 35 by means of the peg 40.

When it is desired to move the rotation disc 13 from the position shown in FIG. 4 to the position shown in FIG. 3, the rotation disc 13 is raised slightly so that the peg 40 becomes free from the groove 42, and when the rotation disc 13 is turned, the peg comes at the groove 41 and the rotation disc 13 can be lowered to the position shown in FIG. 3. At the same time the end of the shaft 12 turns the locking lever 43 inside the shaft 12, whereby the coupling between the shaft 12 and the pulley 25 is uncoupled.

It is natural that the movement of rotation around the axis A--A can be produced, still remaining within the scope of the invention, even in other ways besides by means of the single-belt system shown in FIG. 1, but this system has proved highly reliable in operation. In stead of the single-belt system it would be possible to use two separate belts or various gear or friction-wheel transmissions.

The invention has been tested by means of a prototype in accordance with the figures, in which the mixing revolution numbers were the following: R = number of revolutions of the rotation around the axis B--B = 173 rpm; r.sub.1 = number of revolutions of the rotation by means of the pulley 25 around the axis A--A (smaller, i.e. 0.25 to 3 litre paint cans) = 640 rpm; r.sub.2 = rotation produced by means of the pulley 24 = 320 rpm (for the largest, i.e. 10 litre can size).

It is natural that there can also be more than two speeds of rotation around the axis A--A, for example three or even more.

One of the most important advantages of the present invention is that, when the rotation disc 13 is shifted and the can size changed, at the same time the transmission ratio of the described transmission system is also changed into the correct one by one single operation.

Claims

What I claim is:

1. An improved device for mixing cans of different sizes for paints, in particular paints and toners, which device comprises a pedestal, a frame mounted on said pedestal to rotate around a first axis, a first rotary drive element fastened to said frame to bring about rotation thereof, a disc supported by said frame for fastening a can of paint to said frame, said disc being mounted to rotate around a second axis extending transversely with respect to said first axis, a second rotary drive element fastened to said pedestal coaxially with said first rotary drive element, power means connected to said first rotary drive element to bring about rotation thereof, and driving means connecting said second rotary drive element to said disc to bring about rotation of said disc upon rotation of said first rotary drive element, the improvement consisting in that said disc is axially displaceably supported by said frame, and in that transmission means are coupled between said disc and said driving means, said transmission means being effective to change the number of revolutions of said disc around said second axis when said disc is displaced axially, so that when said disc is at a position corresponding to the largest paint can size, the number of revolutions is lower than when said disc is in a position corresponding to a smaller paint can size.

2. A mixing device according to claim 1, wherein the transmission means comprise a plurality of coaxial rotary drive elements of different respective sizes rotatably mounted to a rotable support, each rotary drive element of said plurality being coupled to said driving means and being selectively coupled in driving engagement with said disc while each other rotary drive element of said plurality is disconnected from engagement with said disc.

3. A mixing device according to claim 2, wherein said driving means comprise a belt and said second rotary drive element and said plurality of rotary drive elements comprise respective pulleys, the belt being trained around said pulleys and around an idler pulley mounted to said frame.

4. A mixing device as claimed in claim 2, comprising peg and hole means coupling said disc to one of said plurality of rotary drive elements.

5. A mixing device according to claim 2, wherein said disc is provided with a tubular shaft and a locking lever provided with a spring is pivotably mounted inside said shaft, said lever pivoting to a coupling position when the shaft is axially displaced to a first position, thus locking one rotary drive element of said plurality in engagement with said shaft, while engagement between each other rotary drive element of said plurality and said disc is disconnected, and pivoting to a releasing position when the shaft is axially displaced to a second position, thus disconnecting said one rotary drive element from engagement with said shaft, while engagement between another rotary drive element of said plurality and said disc is established owing to the axial displacement of said shaft.