GB2323069A

GB2323069A - Conveying apparatus for use in the deposition of paints

Info

Publication number: GB2323069A
Application number: GB9802509A
Authority: GB
Inventors: Patrick Mccormick
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-03-10
Filing date: 1998-02-05
Publication date: 1998-09-16
Anticipated expiration: 2018-02-05
Also published as: GB9802509D0; IE970170A1; GB2323069B

Abstract

Conveying apparatus (1) for conveying components through degreasing station (5), a painting station (3) and a drying station (4) comprises a main conveyor (10) which conveys the components through the stations (5,3,4), the main conveyor (10) includes a main overhead track and a main conveying chain suspended from the overhead track, the main conveyor (10) having an inclined leg 45, for conveying the components through the painting station 3 to the drying station 4, the main conveyor (10) further includes a tensioning unit (63) for tensioning the main conveying chain for accommodation thermal expansion thereof. An input conveyor (11) conveys components to an input station (13) where components are manually transferred from a transfer leg (52) of the input conveyor (11) to a first transfer leg (50) of the main conveyor (10). An output conveyor (12) conveys components away from the main conveyor (10), and a receiving leg (53) of the output conveyor (12) passes adjacent an output station (14) for facilitating manual transfer of components from a second transfer leg (51) of the main conveyor (10) to the receiving leg (53) of the output conveyor (12).

Description

"Conveying apparatus" The present invention relates to a conveying apparatus for conveying components through a painting station and a drying station, and the invention also relates to a method for conveying the components through the painting and drying station using the apparatus according to the invention.

In the manufacture of mechanical components, such as, for example, parts for agricultural machinery, such as, pick-up hitches and the like for tractors, problems arise in the handling, inspecting and painting of such components. Because such parts tend to be relatively large, bulky and heavy, handling of such components tends to be relatively labour intensive. In particular, such components do not lend themselves easily to stacking between the various inspecting and painting operations, and there is a considerable risk of damage to the paint finish of such components during handling and stacking. Additionally, painting of such components, particularly relatively large cumbersome components, can be quite time consuming, and in many cases, it is difficult to achieve an acceptable finish.

There is therefore a need for a conveying apparatus for conveying relatively large cumbersome and heavy components, and in particular for conveying such components through a painting station and a drying station, and for facilitating inspection of such components which overcomes the problems of known apparatus.

The present invention is directed towards providing such conveying apparatus, and the invention is also directed towards providing a method for using the apparatus in the conveying, painting and drying of the components. The invention is also directed to components which have been painted using the conveying apparatus and the method.

According to the invention, there is provided a conveying apparatus comprising a main conveyor for conveying components from an input station through a painting station and a drying station to an output station, the drying station being located at a level higher than the painting station, the main conveyor comprising a main overhead track and a main conveying chain carried on the main overhead track and suspended therefrom, the main conveyor having an inclined leg for conveying the components through the painting station for facilitating painting thereof in the painting station at more than one level, and for conveying the components upwardly through the painting station to the drying station, a tensioning means for tensioning the main conveying chain for accommodating thermal expansion thereof, and a main drive means for driving the main conveying chain.

In one embodiment of the invention the main drive means drives the main conveying chain through a transmission means. Preferably, the transmission means comprises a slipping clutch for preventing sudden stopping and starting of the main conveying chain. Advantageously, the transmission means comprises a means for preventing backward movement of the main conveying chain under the weight of the components when the main drive means is deactivated. Ideally, the means for preventing backward movement of the main conveying chain comprises a worm and gear drive through which drive from the main drive means is transmitted to the main conveying chain.

In one embodiment of the invention a pair of main drive means are provided, each main drive means driving the main conveying chain through respective transmission means. Advantageously, each drive means comprises an electrically powered motor.

In another embodiment of the invention the main overhead track adjacent the tensioning means comprises an arcuate segment forming a 1800 bend in the main conveyor, the arcuate segment having an input end and an output end, and the main overhead track comprises a pair of parallel spaced apart first and second transfer segments for carrying the main conveying chain onto the input end of the arcuate segment, and for receiving the main conveying chain from the output end of the arcuate segment, respectively, the arcuate segment being movable relative to the first and second segments in a direction parallel to the first and second transfer segments, and the tensioning means comprises a means for urging the arcuate segment away from the first and second transfer segments. Preferably, the means for urging the arcuate segment from the first and second transfer segments comprises a spring urging means.

Advantageously, the arcuate segment is slidably mounted relative to the first and second transfer segments.

Preferably, the arcuate segment is carried on a carrier member. Ideally, the carrier member is an elongated member extending parallel to the first and second transfer segments, and ideally the carrier member is horizontally disposed.

In a further embodiment of the invention the conveying chain is passed around a carrier sprocket adjacent the arcuate segment, the carrier sprocket defining a rotational axis which coincides with the axis of generation of the arcuate segment.

In another embodiment of the invention the main overhead track comprises at least one elongated member having an upstanding web, and a pair of sidewardly extending webs extending on opposite sides of the upstanding web for rollably carrying respective rollers from which the main conveying chain is suspended.

Preferably, the side webs extend at the lower end of the upstanding web. Advantageously, one of the side webs of each of the input and output ends of the arcuate segment of the main overhead track overlaps a corresponding portion of the adjacent first or second transfer segment for facilitating transfer of the rollers of a corresponding pair of rollers between the respective first and second transfer and arcuate segments, and preferably, one of the side webs of each of the first and second transfer segments overlaps an adjacent corresponding portion of the input or output ends of the arcuate segment for facilitating transfer of the rollers of a corresponding pair of rollers between the respective first and second transfer and arcuate segments.

Preferably, the arcuate segment is connected to the first and second transfer segments by respective guide means for guiding the movement of the arcuate segment relative to the first and second transfer segments.

In one embodiment of the invention the main conveyor conveys the components through a degreasing station prior to entering the painting station. Preferably, the main conveyor is an endless conveyor.

In another embodiment of the invention the main conveyor comprises two elongated legs extending through the drying station.

Preferably, the direction of movement of the main conveying chain on one of the legs of the main conveyor through the drying station is opposite to the direction of movement of the main conveying chain on the other of the legs through the drying station.

In a further embodiment of the invention an input conveyor is provided for conveying components to the input station for transfer to the main conveyor, the input conveyor comprising an input overhead track and an input conveying chain carried on the input overhead track, and suspended therefrom, and the input conveyor having an elongated transfer leg located adjacent the input station for facilitating transfer of the components from the input conveyor to the main conveyor. Preferably, the transfer leg of the input conveyor extends substantially parallel to a corresponding first transfer leg of the main conveyor, the respective transfer legs of the main and input conveyors being spaced apart from each other.

Advantageously, the input conveying chain moves along the transfer leg of the input conveyor in a direction opposite to the direction of movement of the main conveying chain along the first transfer leg of the main conveyor, for facilitating transfer of components from the input conveyor to the main conveyor.

Preferably, the input conveyor is an endless conveyor.

Ideally, the input conveyor is a relatively long conveyor for facilitating inspection of components being conveyed on the input conveyor.

In a further embodiment of the invention an output conveyor is provided for conveying components from the main conveyor at the output station, the output conveyor comprising an output overhead track and an output conveying chain carried on the output overhead track, and suspended therefrom, and the output conveyor having an elongated receiving leg located adjacent the output station for facilitating transfer of the components from the main conveyor to the output conveyor.

Preferably, the receiving leg of the output conveyor extends substantially parallel to a corresponding second transfer leg of the main conveyor, the receiving leg and the second transfer leg of the main conveyor being spaced apart from each other.

Advantageously, the output conveying chain moves along the receiving leg of the output conveyor in a direction opposite to the direction of movement of the main conveying chain along the second transfer leg of the main conveyor, for facilitating transfer of components from the main conveyor to the output conveyor.

Preferably, the output conveyor is an endless conveyor.

Advantageously, the output conveyor is a relatively long conveyor for facilitating inspection of components being conveyed on the output conveyor.

The invention also provides a method for conveying components through a painting station and a drying station comprising the conveying apparatus according to the invention, the method comprises the steps of placing the components on the main conveyor at the input station, and passing the components through the painting station and the drying station on the main conveyor, and removing the components from the main conveyor at the output station.

In one embodiment of the invention the method further comprises returning the components on the main conveyor to the painting station and the drying station for facilitating further painting and drying of the components.

In another embodiment of the invention the first time the components are passed through the painting station the components are not painted, and are dried on being passed through the drying station for the first time.

Preferably, the method further comprises the step of transferring the components from the input conveyor to the main conveyor at the input station.

In another embodiment of the invention the method further comprises the step of transferring the components from the main conveyor to the output conveyor at the output station.

In a still further embodiment of the invention the method further comprises the step of painting the components as they are passed through the painting station.

In some aspects of the invention the components are degreased as they are conveyed through the degreasing station prior to being conveyed through the painting station.

Preferably, the method further comprises the step of inspecting the components for painting faults on the output conveyor. Advantageously, the components are subjected to an incoming inspection on the input conveyor prior to being transferred to the main conveyor.

The invention also provides a component painted using the conveying apparatus according to the invention.

Further, the invention provides a component painted using the apparatus according to the invention and the method according to the invention.

The invention will be more clearly understood from the following description of a preferred embodiment thereof, which is given by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a schematic perspective view of conveying apparatus according to the invention, Fig. 2 is a schematic plan view of the apparatus of Fig. 1, Fig. 3 is a side elevational view of a portion of the apparatus of Fig. 1, Fig. 4 is a side elevational view of another portion of the apparatus of Fig. 1, Fig. 5 is an underneath plan view of a detail of a portion of the apparatus of Fig. 1, Fig. 6 is a side elevational view of another portion of the apparatus of Fig. 1, Fig. 7 is a sectional end view of the portion of the apparatus of Fig. 6, Fig. 8 is a perspective view of another portion of the apparatus of Fig. 1, Fig. 9 is a perspective view of a detail of the portion of the apparatus of Fig. 8, Fig. 10 is an underneath plan view of another detail of the portion of Fig 8 of the apparatus of Fig. 1, Fig. 11 is an end elevational view of a further portion of the apparatus of Fig. 1, and Fig. 12 is a perspective view of the portion of Fig. 11.

Referring to the drawings, there is illustrated a conveying apparatus according to the invention which is indicated generally by the reference numeral 1 for conveying components, which are indicated by the reference numeral 2, through a paint station 3, a drying station 4, a degreasing station 5 and a flash off station 6. The components 2 are sequentially passed through the stations in the following order.

Initially, the components 2 are passed through the degreasing station 5 for removing grease and the like therefrom. The components 2 then pass through the paint station 3 where they are painted, and onto the flash off station 6 where volatiles are flashed off from the paint and removed. The components 2 then pass through the drying station 4 for drying. The conveying apparatus 1 also facilitates inspection of the components 2 prior to and subsequent to painting as will be described below. In this embodiment of the invention, the components 2 are relatively large cumbersome components, which in this case are parts of agricultural machinery, for example, parts for pick-up hitches of tractors and other such components. For convenience, the components 2 are illustrated in block representation only.

The apparatus 1 comprises three endless conveyors, namely, a main conveyor 10 for conveying the components 2 through the degreasing station 5 and the painting and drying stations 3 and 4 and the flash off station 6, an input conveyor 11 for conveying the components 2 to the main conveyor 10 for transfer thereto at an input station 13, and an output conveyor 12 for conveying components from the main conveyor 10 at an output station 14. Each of the conveyors 10, 11 and 12 comprise an overhead track, the main conveyor 10 comprising a main overhead track 15, the input conveyor 11 comprising an input overhead track 16, and the output conveyor 12 comprising an output overhead track 17. The tracks 15, 16 and 17 are identical and only the main overhead track 15 is illustrated in detail in Figs. 5 to 9. A main conveying chain 20 is carried on and suspended from the main overhead track 15 for conveying the components through the degreasing station 5, the painting station 3, the drying station 4 and the flash off station 6. An input conveying chain 21 which is identical to the main conveying chain 20 is carried on the input overhead track 16 and suspended therefrom for conveying the components to the main conveyor 10.

An output conveying chain 22 which is also identical to the main conveying chain 20 is carried on and suspended from the output overhead track 17 for conveying the components from the main conveyor 10.

Each overhead track 15, 16 and 17 is formed by a plurality of rolled steel joists 25 of I-cross-section which are joined together by welding or otherwise, as will be described below. Lower sidewardly extending side webs 26 which extend from an upstanding central web 27 of the joists 25 rollably carry pairs of rollers 28 which are in turn rotatably mounted on roller carriers 29 from which the corresponding conveying chains 20 are suspended. Component carrying hooks 30 are suspended from and extend downwardly from the roller carriers 29 for carrying the components 2.

Rigid carrier members 31 of steel are welded to and extend upwardly from the joists 25 at spaced apart locations for suspending and carrying the joists 25 from an overhead framework (not shown), which may be a framework constructed specifically for carrying the joists 25, or may be provided by the roof of a building in which the conveying apparatus 1 is located.

The main conveying chain 20 and the input and output conveying chains 21 and 22 are driven by drive means, namely, drive motors 55 through driven sprockets 35 which are located adjacent arcuate bends in the corresponding overhead tracks 15, 16 and 17 where the tracks turn through 1800. The driven sprockets 35 are located adjacent the arcuate bends with the rotational axes of the sprockets 35 coinciding with the corresponding axis of generation of the arcuate bend of the track 15, 16 and 17 for ensuring smooth rolling of the rollers 28 on the side webs 26 of the joists 25 adjacent the respective arcuate bends, see in particular Figs. 11 and 12.

Before describing the input conveyor 11 and the output conveyor 12 in further detail, the main conveyor 10 will first be described as well as its operation through the paint and drying stations 3 and 4, the degreasing station 5 and the flash off station 6. The main conveyor 10 operates at two levels, and comprises a pair of lower legs 38 and 39, and four upper legs 40, 41, 42 and 43. The lower legs 38 and 39 pass through the degreasing station 5 and carry the components 2 therethrough. The upper leg 40 and part of the upper leg 41 pass through the drying station 4, which is at a higher level than the painting station 3 for conveying the components through the drying station 4 for drying thereof. An upwardly inclined leg 45 joins the lower leg 39 with the upper leg 40 and passes through the painting station 3 for conveying the components 2 through the painting station 3 forwardly and upwardly for facilitating painting of the components 2 at more than one level, typically at two or three levels, for painting the top and bottom halves of the component, and in certain cases, for facilitating painting the components at three levels, namely, a top third, a bottom third, and an intermediate third. Platforms (not shown) at varying levels may be provided in the painting station 3 for painters for facilitating the painters to operate at respective different levels within the painting station. A platform (not shown) at an inlet end 47 of the painting station 3, which is adjacent the degreasing station 5 would be located at the lowest level, and a platform (not shown) at the outlet end 48 of the painting station 3 which is adjacent the flash off station 6 would be located at the highest level. The platforms (not shown) may be adjustable.

A downwardly inclined leg 49 of the main conveyor 10 connects the upper leg 43 to the lower leg 38. The upper leg 43 forms a first transfer leg 50 and a second transfer leg 51, which pass by the input station 13 and the output station 14, respectively, and which are located as will be described below parallel to and spaced apart from a transfer leg 52 of the input conveyor 11 for facilitating transfer of components from the input conveyor 11 onto the main conveyor 10, and a receiving leg 53 of the output conveyor 12 for likewise facilitating transfer of components from the main conveyor 10 to the output conveyor 12.

The drive motors 55 for driving the main conveying chain 20 are carried on corresponding subframeworks 56 which are in turn mounted above the rolled steel joists 25 of the main conveyor 10. The drive motors 55 drive the corresponding driven sprockets 35 through corresponding transmission means, namely, slipping clutches 58 and worm and wheel gearboxes 59 for driving the main conveying chain 20. Each worm and wheel gearbox 59 is mounted on the corresponding subframework 56, and the corresponding slipping clutch 58 is located on a corresponding drive shaft 60 between the corresponding gearbox 59 and the driven sprocket 35.

The provision of the slipping clutches 58 prevent sudden stopping and starting of the main conveying chain 20 for avoiding any danger of the components 2 being conveyed on the main conveying chain 20 hitting against each other. Additionally, the slipping clutches 58 prevent overloading of either of the drive motors 55, should the other of the drive motors 55 fail. In which case, the slipping clutch 58 corresponding to the drive motor 55 still operational slips in the event of an overload condition, thereby preventing damage to the operational motor 55. The worm and wheel gearboxes 59 prevent the main conveying chain 20 moving backwards under the weight of components 2 in the event of the motors 55 being deactivated.

A tensioning means for tensioning the main conveying chain 20 for accommodating thermal expansion thereof resulting from the heat of the drying station 4 comprises a tensioning assembly 63 which is located between the legs 41 and 42 of the main conveyor 10.

The tensioning assembly 63 comprises an arcuate segment 64 which is formed by one of the rolled steel joists 25 of the main track 15, and which is bent through 1800.

The arcuate segment 64 terminates at one end in an input end 65, and at the other end in an output end 66.

A pair of adjacent parallel spaced apart first and second transfer segments 68 and 69, respectively, also formed by the rolled steel joists 25 of the legs 41 and 42, respectively, of the main track 15 are located adjacent the arcuate segment 64. The first transfer segment 68 is aligned with the input end 65 for facilitating transfer of the rollers 28 onto the input end 65 of the arcuate segment 64, and the second transfer segment 69 is located adjacent the output end 66 of the arcuate segment 64 for facilitating transfer of the rollers 28 from the output end 66 of the arcuate segment 64 onto the segment 69.

The arcuate segment 64 is slidably carried on a horizontal carrier member 70 provided by a rolled steel joist which extends parallel to the first and second transfer segments 68 and 69. A bracket 71 extending upwardly from the arcuate segment 64 carries a roller 72 which rollably engages the carrier member 70 for facilitating sliding movement of the arcuate segment 64 towards and away from the segments 68 and 69 for accommodating expansion and contraction of the main conveying chain 20.

A pair of guide means, namely, a pair of guide rods 74 extend from the input and output ends 65 and 66 of the arcuate segment 64 and slidably engage corresponding bores 75 in corresponding guide members 76 which are welded to the segments 68 and 69 for guiding the arcuate segment 64 to move parallel to the first and second transfer segments 68 and 69 in the direction of the arrows A and B. Mounting members 77 welded to the arcuate segment 64 carry the guide rods 74. The carrier member 70 is carried on a carrier framework 78 which is secured to the first and second transfer segments 68 and 69 by a subframework (not shown). A tension spring 80 anchored to the carrier framework 78 and arcuate segment 64 urges the arcuate segment 64 in the direction of the arrow A away from the first and second transfer segments 68 and 69 for inducing tension in the main conveying chain 20.

A portion 82 of one of the side webs 26 extends from the respective input and output ends 65 and 66 of the arcuate segment 64 for overlapping a portion of the corresponding first and second transfer segments 68 and 69. A portion 83 of one of the side members 26 of each of the first and second transfer segments 68 and 69 overlap the input and output ends 65 and 66 of the arcuate segment 64. This facilitates smooth transfer of the rollers 28 on each roller carrier 29 between the arcuate segment 64 and the first and second transfer segments 68 and 69 in the event that the spacing between the arcuate segments 64 and the first and second transfer segments 68 and 69 is relatively large due to movement of the arcuate segment 64 in the direction of the arrow A.

The input conveyor 11 comprises four legs, namely legs 87, 88, 89 and 90. Arcuate segments 91 formed by rolled steel joists 25 join the corresponding legs 87, 88, 89 and 90 together. Two drive motors 55 which are mounted on subframeworks (not shown but which are similar to the subframework 56) drive the input conveying chain 21 of the input conveyor 11 through the driven sprockets 35 in similar fashion as the main conveying chain 20 is driven. The drive motors 55 drive the driven sprockets 35 of the input conveyor 11 through input transmission means, which are substantially similar to the main transmission means of the main conveyor 10 and each comprise a slipping clutch 96 and a worm and wheel gearbox 97, which are similar to the slipping clutch 58 and gearbox 59 already described with reference to the main input conveyor 10. The transfer leg 52 is formed by part of the leg 90 of the input conveyor 11, and as can be seen, passes adjacent the input station 13, and is spaced apart and extends parallel to the first transfer leg 50 of the main conveyor 10 for facilitating transfer of components to be painted from the input conveyor 11 to the main conveyor 10. Additionally, for further facilitating transfer of the components from the input conveyor 11 to the main conveyor 10, the direction of movement of the input conveying chain (not shown) is directly opposite in the direction of movement of the main conveying chain 20 of the main conveyor 10 adjacent the input station 13. This facilitates direct manual transfer of the components from the input conveyor 11 to the main conveyor 10 by the operator. The main conveying chain moves in the direction of the arrow C, while the input conveying chain moves in the direction of the arrow D.

Upwardly and downwardly inclined intermediate legs 99 formed in the respective legs 90 and 89 connect higher portions of the input conveyor 16 to lower portions thereof. The transfer leg 52 of the input conveyor 11 and the corresponding part of the leg 89 of the input conveyor 11 are at a high level corresponding to the level of the transfer leg 43 of the main conveyor 10 at the input station 13. The legs 87 and 88 are at a lower level so that components 2 to be conveyed by the input conveyor 11 can be attached to the legs 87 and 88 at floor level, and additionally, may be inspected at floor level, prior to being transferred to the main conveyor 10.

Turning now to the output conveyor 12, the output conveyor 12 comprises the receiving leg 53 and a leg 100, both of which are at a higher level to a plurality of legs 101. The legs 53 and 100 are joined to the legs 101 by upwardly and downwardly inclined legs 103 and 104, respectively. A leg 106 joins the leg 103 to the legs 101, and a leg 107 joins the leg 104 to the receiving leg 53. The output conveying chain 22 of the output conveyor 12 is driven in similar fashion as the main conveying chain 20 of the main conveyor 10 by the drive motor 55 through a worm and wheel gearbox 110, a slipping clutch 109 and the driven sprocket 35. The receiving leg 53 of the output conveyor 12 is spaced apart from and extends parallel to the transfer leg 43 of the input conveyor 10 adjacent the output station 14 for facilitating manual transfer of painted components from the main conveyor 10 to the output conveyor 12.

The receiving leg 53 is at the same level as the second transfer leg 51 of the main conveyor 10. Additionally, to further facilitate manual transfer of the components 2 from the main conveyor 10 to the output conveyor 12, the output conveying chain 22 moves in the direction of the arrow E which is opposite to the direction of movement C of the main conveying chain 20 of the main conveyor 10.

The legs 101 of the output conveyor 12 are at a level above the floor for facilitating removal of components from the output conveyor 12 at floor level, and also for facilitating inspection and other quality control operations at floor level of the finished painted components 2 prior to their removal from the output conveyor 12. Additionally by virtue of the number and relatively long length of the legs 101, the legs 101 of the output conveyor 12 effectively act as a buffer store for components as they are being conveyed on the output conveyor 12.

In use, components to be painted are initially manually attached to the legs 87 and 88 of the input conveyor 11 at floor level. The components are manually transferred by an operator from the transfer leg 52 of the input conveyor 11 to the first transfer leg 50 of the main conveyor 10 at the input station 13. The components are then conveyed on the main conveyor through the degreasing station 5, where the components are degreased, the painting station 3 for painting of the components, the flash off station 6 where volatiles released from the paint on the components 2 are drawn off, and the drying station 4 for drying of the components. The finished painted components are then manually transferred by an operator at the output station 14 from the second transfer leg 51 of the main conveyor 10 to the receiving leg 53 of the output conveyor 12. Inspection and other quality control operations are carried out on the finished components on the legs 101 of the output conveyor 12, and then the components are manually removed from the legs 101 of the output conveyor 12 for subsequent assembly and packaging.

In certain cases, components may require shot blasting, and the shot blasting operation is carried out on the components on the leg 88 of the input conveyor 11.

Some of the components for various reasons may not require degreasing, and in which case the degreasing station is deactivated while the components are being conveyed therethrough on the main conveyor 10.

Initially, the components are primed with a suitable primer paint in the pain components are allowed to remain on the main conveyor 10 for a second pass through the degreasing station 5, and the painting and drying stations 3 and 4. On the second pass, the degreasing station 5 is deactivated, and the primed components are sprayed with a finishing coat in the painting station 3 which is in turn cured in the drying station 4. Provided the components require no further painting, they are then transferred from the second transfer leg 51 of the main conveyor 10 at the output station 14 onto the receiving leg 53 of the output conveyor 12. In cases where more than one finishing coat, or more than one priming coat are required, the components remain on the main conveyor 10 for the appropriate number of passes, so that the appropriate number of coats of paint or primer may be applied to the components.

The advantages of the invention are many. One of the main advantages of the invention is that once the components are attached to the input conveyor, no further storing of the components between various operations is required until the components are finished and ready for subsequent assembly and packaging when they are removed from the output conveyor. This is a particularly important advantage where the components are relatively large, cumbersome and heavy, since the storage of such components can be difficult, requires a lot of space, and also may result in causing damage to the components. Additionally, by virtue of the fact that the main, input and output conveyors operate at two levels, significant saving of space is provided. Furthermore, by virtue of the fact that the drying station is at a level above the painting station, and the components transfer directly from the painting station through the flash off station into the drying station, emission of fumes from the painting station can more easily be controlled, and the working environment in the painting station is significantly improved.

By virtue of the fact that the conveying chains of the main, input and output conveyors are driven through slipping clutches, there is no danger of sudden starts and stops in the conveyors, and thereby the danger of adjacent components on the conveyors banging into each other and being damaged is virtually eliminated.

Furthermore, by virtue of the fact that the conveying chains of the main, input and output conveyors are driven through worm and wheel gearboxes, in the event of a drive motor failing or being deactivated, there is no danger of the corresponding conveying chain moving backwards as a result of the weight of the components on an inclined leg of the conveyor.

A further advantage of the invention is that by providing the inclined leg of the main conveyor extending through the painting station, the components may be sprayed at a number of different levels in the painting stations, this is a particular advantage where relatively large, and in particular relatively long components from top to bottom are being conveyed through the painting station.

Claims

1. A conveying apparatus comprising a main conveyor for conveying components from an input station through a painting station and a drying station to an output station, the drying station being located at a level higher than the painting station, the main conveyor comprising a main overhead track and a main conveying chain carried on the main overhead track and suspended therefrom, the main conveyor having an inclined leg for conveying the components through the painting station for facilitating painting thereof in the painting station at more than one level, and for conveying the components upwardly through the painting station to the drying station, a tensioning means for tensioning the main conveying chain for accommodating thermal expansion thereof, and a main drive means for driving the main conveying chain.

2. A conveying apparatus as claimed in Claim 1 in which the main drive means drives the main conveying chain through a transmission means.

3. A conveying apparatus as claimed in Claim 2 in which the transmission means comprises a slipping clutch for preventing sudden stopping and starting of the main conveying chain.

4. A conveying apparatus as claimed in Claim 2 or 3 in which the transmission means comprises a means for preventing backward movement of the main conveying chain under the weight of the components when the main drive means is deactivated.

5. A conveying apparatus as claimed in Claim 4 in which the means for preventing backward movement of the main conveying chain comprises a worm and gear drive through which drive from the main drive means is transmitted to the main conveying chain.

6. A conveying apparatus as claimed in any of Claims 2 to 5 in which a pair of main drive means are provided, each main drive means driving the main conveying chain through respective transmission means.

7. A conveying apparatus as claimed in any preceding claim in which each main drive means comprises an electrically powered motor.

8. A conveying apparatus as claimed in any preceding claim in which the main overhead track adjacent the tensioning means comprises an arcuate segment forming a 1800 bend in the main conveyor, the arcuate segment having an input end and an output end, and the main overhead track comprises a pair of parallel spaced apart first and second transfer segments for carrying the main conveying chain onto the input end of the arcuate segment, and for receiving the main conveying chain from the output end of the arcuate segment, respectively, the arcuate segment being movable relative to the first and second segments in a direction parallel to the first and second transfer segments, and the tensioning means comprises a means for urging the arcuate segment away from the first and second transfer segments.

9. A conveying apparatus as claimed in Claim 8 in which the means for urging the arcuate segment from the first and second transfer segments comprises a spring urging means.

10. A conveying apparatus as claimed in Claim 8 or 9 in which the arcuate segment is slidably mounted relative to the first and second transfer segments.

11. A conveying apparatus as claimed in any of Claims 8 to 10 in which the arcuate segment is carried on a carrier member.

12. A conveying apparatus as claimed in Claim 11 in which the carrier member is an elongated member extending parallel to the first and second transfer segments.

13. A conveying apparatus as claimed in Claim 11 or 12 in which the carrier member is horizontally disposed.

14. A conveying apparatus as claimed in any of Claims 8 to 13 in which the main overhead track comprises at least one elongated member having an upstanding web, and a pair of sidewardly extending webs extending on opposite sides of the upstanding web for rollably carrying respective rollers from which the main conveying chain is suspended.

15. A conveying apparatus as claimed in Claim 14 in which the side webs extend at the lower end of the upstanding web.

16. A conveying apparatus as claimed in Claim 14 or 15 in which one of the side webs of each of the input and output ends of the arcuate segment of the main overhead track overlaps a corresponding portion of the adjacent first or second transfer segment for facilitating transfer of the rollers of a corresponding pair of rollers between the respective first and second transfer and arcuate segments.

17. A conveying apparatus as claimed in any of Claims 14 to 16 in which one of the side webs of each of the first and second transfer segments overlaps an adjacent corresponding portion of the input or output ends of the arcuate segment for facilitating transfer of the rollers of a corresponding pair of rollers between the respective first and second transfer and arcuate segments.

18. A conveying apparatus as claimed in any of Claims 8 to 17 in which the arcuate segment is connected to the first and second transfer segments by respective guide means for guiding the movement of the arcuate segment relative to the first and second transfer segments.

19. A conveying apparatus as claimed in any preceding claim in which the main conveyor conveys the components through a degreasing station prior to entering the painting station.

20. A conveying apparatus as claimed in any preceding claim in which the main conveyor is an endless conveyor.

21. A conveying apparatus as claimed in any preceding claim in which the main conveyor comprises two elongated legs extending through the drying station.

22. A conveying apparatus as claimed in Claim 21 in which the direction of movement of the main conveying chain on one of the legs of the main conveyor through the drying station is opposite to the direction of movement of the main conveying chain on the other of the legs through the drying station.

23. A conveying apparatus as claimed in any preceding claim in which an input conveyor is provided for conveying components to the input station for transfer to the main conveyor, the input conveyor comprising an input overhead track and an input conveying chain carried on the input overhead track, and suspended therefrom, and the input conveyor having an elongated transfer leg located adjacent the input station for facilitating transfer of the components from the input conveyor to the main conveyor.

24. A conveying apparatus as claimed in Claim 23 in which the transfer leg of the input conveyor extends substantially parallel to a corresponding first transfer leg of the main conveyor, the respective transfer legs of the main and input conveyors being spaced apart from each other.

25. A conveying apparatus as claimed in Claim 24 in which the input conveying chain moves along the transfer leg of the input conveyor in a direction opposite to the direction of movement of the main conveying chain along the first transfer leg of the main conveyor, for facilitating transfer of components from the input conveyor to the main conveyor.

26. A conveying apparatus as claimed in any of Claims 23 to 25 in which the input conveyor is an endless conveyor.

27. A conveying apparatus as claimed in any of Claims 23 to 26 in which the input conveyor is a relatively long conveyor for facilitating inspection of components being conveyed on the input conveyor.

28. A conveying apparatus as claimed in any preceding claim in which an output conveyor is provided for conveying components from the main conveyor at the output station, the output conveyor comprising an output overhead track and an output conveying chain carried on the output overhead track, and suspended therefrom, and the output conveyor having an elongated receiving leg located adjacent the output station for facilitating transfer of the components from the main conveyor to the output conveyor.

29. A conveying apparatus as claimed in Claim 28 in which the receiving leg of the output conveyor extends substantially parallel to a corresponding second transfer leg of the main conveyor, the receiving leg and the second transfer leg of the main conveyor being spaced apart from each other.

30. A conveying apparatus as claimed in Claim 28 or 29 in which the output conveying chain moves along the receiving leg of the output conveyor in a direction opposite to the direction of movement of the main conveying chain along the second transfer leg of the main conveyor, for facilitating transfer of components from the main conveyor to the output conveyor.

31. A conveying apparatus as claimed in any of Claims 28 to 30 in which the output conveyor is an endless conveyor.

32. A conveying apparatus as claimed in any of Claims 28 to 31 in which the output conveyor is a relatively long conveyor for facilitating inspection of components being conveyed on the output conveyor.

33. A conveying apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.

34. A method for conveying components through a painting station and a drying station comprising the conveying apparatus as claimed in any preceding claim in which the method comprises the steps of placing the components on the main conveyor at the input station, and passing the components through the painting station and the drying station on the main conveyor, and removing the components from the main conveyor at the output station.

35. A method as claimed in Claim 34 in which the method further comprises returning the components on the main conveyor to the painting station and the drying station for facilitating further painting and drying of the components.

36. A method as claimed in Claim 34 or 35 in which the first time the components are passed through the painting station the components are not painted, and are dried on being passed through the drying station for the first time.

37. A method as claimed in any of Claims 34 to 36 in which the method further comprises the step of transferring the components from the input conveyor to the main conveyor at the input station.

38. A method as claimed in any of Claims 34 to 37 in which the method further comprises the step of transferring the components from the main conveyor to the output conveyor at the output station.

39. A method as claimed in any of Claims 34 to 38 in which the method further comprises the step of painting the components as they are passed through the painting station.

40. A method as claimed in any of Claims 34 to 39 in which the components are degreased as they are conveyed through the degreasing station prior to being conveyed through the painting station.

41. A method as claimed in any of Claims 34 to 40 in which the method further comprises the step of inspecting the components for painting faults on the output conveyor.

42. A method as claimed in any of Claims 34 to 41 in which the components are subjected to an incoming inspection on the input conveyor prior to being transferred to the main conveyor.

43. A method for conveying components through a painting station and a drying station, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.

44. A component painted using the conveying apparatus as claimed in any of Claims 1 to 33.

45. A component painted using the apparatus as claimed in any of Claims 1 to 33 and the method as claimed in any of Claims 34 to 43.