EP0899021A1

EP0899021A1 - Painting device

Info

Publication number: EP0899021A1
Application number: EP98202517A
Authority: EP
Inventors: Leopold Vanhauwaert
Original assignee: Makova NV
Current assignee: Makova NV
Priority date: 1997-07-30
Filing date: 1998-07-27
Publication date: 1999-03-03
Also published as: BE1011306A5

Abstract

This invention relates to a painting device comprising a paint spraying installation provided with at least one spraying element and a rotation installation (12), (13) provided with at least one means of rotation (25) disposed under the spraying level of the spraying element which through a drive mechanism (14), (15) disposed principally above this spraying level is drivable in order to rotate in relation to the spraying element a product to be painted, so that various parts of the product are brought within the spraying range of the spraying element.
According to this invention the aforementioned means of rotation is provided for raising and supporting the product during the rotation thereof. Because of this is possible to enable the feeding and removal of products to take place over one continuous conveyor surface. Because of this the device is less complex, fully automatic and especially well suited to heavy products.

Description

This invention relates to a painting device comprising a paint spraying installation provided with at least one spraying element and a rotation installation provided with at least one means of rotation disposed under the spraying level of the spraying element which through a drive mechanism disposed principally above this spraying level is drivable in order to rotate in relation to the spraying element a product to be painted, so that various parts of the product are brought within the spraying range of the spraying element.
This invention relates in particular to such a painting device for painting products with a principally cylindrical shape. An important field of application for these types of devices is painting metal drums with principally cylindrical shape.
Devices exist for painting metal drums with the characteristics mentioned in the first paragraph of this specification. These devices comprise a supporting structure on which the spraying installation and the rotation installation are provided. The drums are brought in an upright position to the rotation installation. The rotation installation comprises four rollers which can be rotated by a drive device and can be brought into contact with the cylindrical side wall of a drum in order to hold this drum clamped between the rollers and in order to rotate the drum through the rotation of the rollers. At various heights next to the rotation installation several sideways directed spray guns are provided for painting the side wall of the drums. Furthermore on top a downwardly directed spray gun is provided for painting the top of the drums, and underneath an upwardly directed spray gun is provided for painting the underside of the drums. Usually there are also provisions for circumscribing the paint spraying area during painting by means of a water curtain in order in as far as possible to prevent the paint from falling next to the painting device and from adversely influencing the working conditions in the vicinity of this device. The known devices can be operated in order to paint several drums one after the other automatically. On the supporting structure a conveyor means is provided for automatically feeding drums to be painted to the rotation installation and for automatically removing the painted drums.
With these known painting devices the drive device for the rotation installation is always mounted on a lower part of the supporting structure, so that the distance between the drive mechanism and the rollers driven by it is minimal.
A great disadvantage of the known devices is that a considerable part of the paint which does not reach the drums falls on to this drive device, so that this device has to be cleaned frequently. With normal use of the painting device this cleaning has to be carried out daily. This is furthermore very time-consuming work. Because of the fact that the paint removed from this drive device cannot be reused every cleaning operation produces an amount of environmentally damaging waste.
From the American patent US-1 742 393 a device is known with a turntable for rotating cylindrical drums in relation to a spraying installation. The turntable is drivable by means of a mechanism whose drive shaft is above the spraying installation. The feeding of the drums is effected on a feed band conveyor, from on which the drums have to be manually placed on the still standing turntable. The removal of the drums is effected on a removal band conveyor on which the finished drums likewise have to be placed through the intervention of an operator.
This device however has a series of considerable disadvantages. A first disadvantage is that this device is not fully automatic. The device is furthermore also not suitable for painting rather heavy products since a manual movement of the products has to occur. Also the drive mechanism of the turntable is rather complex, and fouling of the parts disposed above the spraying level is not excluded.
The purpose of this invention is to provide a painting device with which the above mentioned disadvantages are remedied.
This purpose is achieved according to this invention by providing a painting device with the characteristics mentioned in the first paragraph of this specification, of which the means of rotation is provided for raising and supporting the product during the rotation thereof.
Because of this it is possible to carry out on the one hand the feeding of products to be painted to the rotation installation and on the other hand the removal of painted products over one continuous surface or with one continuous means of conveyance (e.g. a band conveyor). The means of rotation can indeed raise the products off the surface or means of conveyance in order to rotate them. This is especially advantageous where relatively heavy products are concerned, such as for example metal drums. A fully automatic device is also thus obtained, which is less complex than existing devices.
Through the disposition of the drive mechanism the amount of paint which falls on the drive mechanism is greatly reduced, so that the time-consuming and environmentally damaging cleaning operations are no longer needed, or certainly no longer have to be carried out so frequently as with the known devices.
Furthermore in the lower part of the painting device room can also be made free in order to provide means for the recyclable collection of the fallen paint. Such means can for example consist of a water tank extending under each spraying element which delimits the painting device underneath. During use of the painting device a considerable amount of paint will fall into the water provided in this water tank. Non-water-soluble thinner-based paint types can be recovered from this water and be used again. Because of this, use of the painting device is far less environmentally damaging while a saving in paint consumption is furthermore achieved.
The aforementioned means of rotation is preferably a revolvable roller, which is provided in order through its rotation in contact with a product to be painted, to achieve a rotation of the product.
A very advantageous embodiment is obtained according to this invention if at least one roller is revolvable round an almost vertical axis of rotation and terminates underneath with a conical part whose diameter increases in downward direction, while this roller is movable in sideways direction so that a product is brought upwards by an inclined flank of the conical part of the roller, and while the product resting on this flank can be rotated by the roller.
As a result of one and the same sideways movement of the roller the roller is brought into contact with the object to be painted in order to rotate this object and the object is raised. For the raising of an object consequently no upwardly moving parts are required so that the rotation device can be constructed with rather simple means. Furthermore during its rotation the object is supported by the conical roller part, so that the rotating of heavy products can occur without any problem.
The rotation device preferably comprises at least three rollers, which are movable between a first position whereby they are not in contact with a product placed between the rollers and a second position whereby they are in contact with an outer wall of the product in order to hold and rotate the product clamped between the rollers.
Such a rotation device works very efficiently, in particular for rotating relatively heavy cylindrical objects, such as for example metal drums.
A very advantageous embodiment is obtained if each roller is mounted on a respective rotary shaft, which extends to above the spraying level of each spraying element and can be rotated by the aforementioned drive mechanism. Because of this another disadvantage of the device known from US-1 742 393 is remedied. This device namely has a drive belt which runs both over a turntable disposed under the turntable and over a roller drivable by the drive shaft - above the spraying level, so that every part of the belt in every revolution comes successively under and over the spraying level and can thus foul the parts disposed above the spraying level. By making use of drive shafts, this is remedied and a device is obtained whereby any fouling of parts above the spraying level is excluded.
With another very preferred embodiment of the painting device according to this invention each rotary shaft is connected to a swivel arm provided above the spraying level of each spraying element which is rotatably mounted so that the rotary shaft can be moved by the rotation of the swivel arm between a first position whereby the roller mounted thereon is not in contact with a product placed opposite the roller and a second position whereby this roller is namely in contact with the product.
The painting device according to this invention in a most preferred embodiment comprises a conveyor device which can be operated in order to feed products to be painted automatically one after the other to the rotation installation, and in order to remove automatically each product there from after painting, while the drive mechanism can be operated in order to place each swivel arm successively in the aforementioned first position during the feeding of a product to be painted, to place it in the aforementioned second position in order rotate a fed product, and to place it back in the first position during the removal of the painted product.
In order to achieve an optimum paint recovery and therefore a reduced paint consumption this device is provided with a water tank extending under each spraying element, which underneath circumscribes the device.
This invention will now be further explained hereafter in the following detailed specification of a painting device according to this invention. This specification can in no way be considered as restrictive for the scope of the protection claimed for this invention in the claims. In this invention reference is made to the figures attached hereto, of which
Figure 1 represents a view from above of a painting device with two spraying installations according to this invention,
Figure 2 represents an enlarged view from above of a part of a drive device of a rotation installation of the painting device in figure 1,
Figure 3 represents a side view of a part of the painting device shown in figure 1, and
Figure 4 represents a front view of a part of the painting device shown in figure 1.
A preferred embodiment of the painting device comprises, as can readily be seen in figures 3 and 4, a supporting structure (1) constructed out of metal sections (2), (3). The supporting structure (1) comprises sections (2) which extend in two parallel vertical planes, and sections (3) which form a horizontal connection between the tops of a number of the first mentioned sections (2) so that a tunnel-shaped construction is obtained with a horizontal passage room (4) circumscribed by sections (2), (3).
In the lower part of the passage room (4) a number of parallel guiding slats (5) are provided extending over the full length of the passage room (4) in a horizontal plane (see figure 1), while a conveyor device (6), principally consisting of a chain or band (9) running over two horizontally disposed rollers (7), (8) with engaging means, with which drums can be slidingly moved over the guiding slats (5) through the passage room (4).
The painting device comprises a spraying installation with two spraying stations (10), (11), respectively provided with spray guns disposed along the passage room (4) for painting the side wall, top and bottom of a drum rotating in the passage room (4) and in the spraying station (10), (11). The spray guns provided, their location and method of arrangement and the other parts of the spraying installation are generally known in this field. Consequently no parts of the spraying installation have been represented in the drawings.
The painting device further also comprises a rotation installation (12), (13) near each spraying station (10), (11). Each rotation installation (12), (13) comprises a drive device (14), (15) which is disposed above the horizontal running sections (3) of the supporting structure (1), and therefore above the passage room (4).
Each drive device (14), (15) comprises (see figure 2) four horizontal swivel arms (16) which are mounted on a fixed part of the painting device rotatable round respective vertical shafts (17). The swivel arms (16) are disposed in twos on both sides of a vertical plane of symmetry (18) in the longitudinal direction of the passage room (4) and support vertical rotary shafts (19) which extend downwards in the passage room (4). In figure 2 the swivel arms (16) along the left-hand side of the plane of symmetry (18) are not represented in full, and the left-hand rotary shafts (19) and rollers (25) are not represented.
Toothed wheels (not represented in the figures) are provided on the vertical shafts (17) of the swivel arms (16). The toothed wheels on the shafts (17) of each pair of swivel arms (16) provided along the same side of the plane of symmetry (18) so work together that a rotation of one swivel arm (16) in the direction of the plane of symmetry brings about one and the same rotation of the other swivel arm (16) in the same direction.
Round both shafts (17) of the swivel arms (16) of the left-hand pair (see figure 2), and on a shaft (17) of one of the swivel arms (16) of the right-hand pair rods (20), (21), (22) are respectively attached.
The rod (22) on the shaft (17) of one of the right-hand swivel arms (16) and the rod (20) on the shaft (17) of one of the left-hand swivel arms (16) are connected to each other by means of a bar (23). The rod (21) on the shaft (17) of the other left-hand swivel arm (16) is connected to the movable part (23) of a hydraulic cylinder (24), whose fixed part is rotatably connected to a fixed part of the painting device.
By means of the hydraulic cylinder (24) one of the left-hand swivel arms (16) can be rotated. Through toothed wheels working together on the shafts (17) of the two left-hand swivel arms (16), the other left-hand swivel arm (16) gets a corresponding rotation which by means of the bar (23) is transmitted to one of the right-hand swivel arms (16). Through the toothed wheels working together on the shafts (17) of the two right-hand swivel arms (16) the other right-hand swivel arm (16) also gets a corresponding rotation.
By operating the hydraulic cylinder (24) all swivel arms (16) can therefore be rotated either towards the plane of symmetry (18), or away from the plane of symmetry (18).
On the four downwardly extending rotary shafts (19), approximately at the level of the guiding slats (5), respective rollers (25) are mounted. The rotary shafts can be rotated above the passage room (4) by means of hydraulic motors (not represented in the figures). The rotary shafts (19) are in tubes (26).
Each roller (25) has an upper cylindrical part (26) and a lower conical part (27) whose diameter increases downwards (see figure 4).
The conveyor device (6) can be operated in order to bring a drum to be painted automatically into the first spraying station (10) in order to paint a part of the drum with paint of a first colour, in order to bring the drum after the first painting operation automatically to the second spraying station (11) in order to paint another part of the drum with a paint of a second colour, and in order to remove the drum automatically after this second painting operation to the end point of the conveyor device (6).
The fact that the two colours are applied in two consecutive spraying stations (10), (11), and not in one and the same spraying station has the effect that the paint from the first painting operation can dry during the conveyance of the drum to the second spraying station (11). Because of this the capacity of the painting device is increased.
Each time a drum to be painted is brought into a spraying station (10), (11), the hydraulic cylinder (24) of the drive device (14), (15) of the rotation installation (12), (13) provided for this spraying station is operated in order to rotate the swivel arm (16) in the direction of the plane of symmetry (18). Moreover each roller (25) is pushed with the conical part (27) under the bottom surface of the drum, so that the drum is raised and is supported by the conical parts of the four rollers (25) and no longer rests on the guiding slats (5).
The cylindrical parts (26) of the rollers (25) are then against the side wall of the drum. The hydraulic motors are subsequently operated in order to rotate the rotary shafts (19) with the rollers (25), so that the drum is also rotated. Meanwhile the spraying installation is operated in order to spray paint out of the spray guns, so that the rotating drum is painted.
When the drum has been painted, the hydraulic motors are stopped so that the rotation of the drum is discontinued and the pneumatic cylinder (24) is operated in order to turn the swivel arms (16) away from the plane of symmetry (18) so that the drum is again deposited on the guiding slats (5) and can be taken along by the conveyor device (6).
Because of the fact that the drive devices (14), (15) are above the spraying level of the spray guns, these are no longer fouled by the paint. The time-consuming and environmentally damaging cleaning operations are therefore no longer necessary with this painting device.
Preferably a water tank is provided under the conveyor device (6) in order to make the recovery of dripping paint possible. Because of this savings are made on the consumption of paint and the amount of environmentally damaging waste is reduced.

Claims

Painting device comprising a paint spraying installation provided with at least one spraying element and a rotation installation (12), (13) provided with at least one means of rotation (25) disposed under the spraying level of the spraying element which through a drive mechanism (14), (15) disposed principally above this spraying level is drivable in order to rotate in relation to the spraying element a product to be painted, so that various parts of the product are brought within the spraying range of the spraying element, characterised in that the means of rotation (25) is provided in order to raise and support the product during the rotation thereof.
Painting device according to claim 1 characterised in that the means of rotation is a revolvable roller (25), which is provided in order through its rotation in contact with a product to be painted, to achieve a rotation of the product.
Painting device according to claim 2 characterised in that at least one roller (25) is revolvable round an almost vertical axis of rotation and terminates underneath with a conical part whose diameter increases in downward direction, that this roller (25) is movable in sideways direction so that a product is brought upwards by an inclined flank of the conical part of the roller (25), and that the product resting on this flank can be rotated by the roller (25).
Painting device according to claim 2 or 3 characterised in that the rotation installation (12), (13) comprises at least three rollers (25), which are movable between a first position whereby they are not in contact with a product placed between the rollers (25) and a second position whereby they are in contact with an outer wall of the product in order to hold and rotate the product clamped between the rollers (25).
Painting device according to any of the preceding claims characterised in that each roller (25) is mounted on a respective rotary shaft (19), which extends to above the spraying level of each spraying element and can be rotated by the aforementioned drive mechanism (14), (15).
Painting device according to claim 5 characterised in that each rotary shaft (19) is connected to a swivel arm (16) provided above the spraying level of each spraying element which is rotatably mounted so that the rotary shaft (19) can be moved by the rotation of the swivel arm (16) between a first position whereby the roller (25) mounted thereon is not in contact with a product placed opposite the roller and a second position whereby this roller is namely in contact with the product.
Painting device according to claim 6 characterised in that the device comprises a conveyor device (6) which can be operated in order to feed products to be painted automatically one after the other to the rotation installation (12), (13), and in order to remove automatically each product there from after painting, that the drive mechanism (14), (15) can be operated in order to place each swivel arm (16) successively in the aforementioned first position during the feeding of a product to be painted, to place it in the aforementioned second position in order rotate a fed product, and to place it back in the first position during the removal of the painted product.
Painting device according to any of the preceding claims characterised in that this device is circumscribed underneath by a water tank extending under each spraying element.
Painting device according to any of the preceding claims characterised in that this device is provided for painting metal drums with a principally cylindrical shape.