WO2000058187A1

WO2000058187A1 - Machine for treatment of plate-shaped objects

Info

Publication number: WO2000058187A1
Application number: PCT/SE2000/000564
Authority: WO
Inventors: Stig Larsson; Rolf Nilsson
Original assignee: Sigma Holding Ab
Priority date: 1999-03-26
Filing date: 2000-03-23
Publication date: 2000-10-05
Also published as: SE9901109L; SE513770C2; AU4157600A; SE9901109D0

Abstract

A machine for treating panels with chemicals for forming an electrophoretic resist comprises receptacles (10) for the treatment media, a vertical-carriage (11) for each receptacle (10), transportation brackets (29) with horizontalcarriages (30) for moving a transportation bracket between the verticalcarriages and panel brackets (28). Feeding and transport devices form a transport loop between the loading and unloading stations (5, 6). Each panel carrier has first holding members (37) and second holding members (38) for holding the panel, respectively, by its upper edge and two lateral edges.

Description

Machine for treatment of plate-shaped objects

The present invention relates to a machine for treating panel-like plate-shaped objects, containing electrically conductive material, with different mediums which comprise a chemical solution for electro deposition of an electrophoretic resistant coating on at least one side of the panel, which machine comprises an inlet end, an outlet end, a plurality of receptacles for said treatment mediums, a vertical-carriage arranged in connection with each receptacle for movement up and down, a plurality of transportation brackets with horizontal-carriages for moving a transportation bracket from one vertical-carriage to an immediately following vertical-carriage, a plurality of panel carriers arranged to be carried by the transportation brackets for carrying one or several panels, and a plurality of transportation lines combined in a transportation loop for moving the transportation brackets in a circuit .

Machines for manufacturing electrophoretic resistant coatings on electrically conductive panels, out of which printed circuit boards are to be manufactured, are known, for instance through SE-C2-509 419. In the known machines, the panels are handled manually to fasten the panels to the panel carriers at the loading end of the machine and to detach the treated panels from the panel carriers at the unloading end of the machine . Such a machine therefore requires considerable manual attendance during operation and has low capacity due to the panels having to be handled manually one by one. The panels are suspended from the panel carriers by way of clamps on the upper edge of the panels . This entails that the panels can easily be deflected from their vertical plane under the influence of the liquids and air with which the panels are treated, partly by way of currents in these mediums and partly by way of the automotion to which the panels are intentionally subjected to increase the effect of the treatment. Neither is it possible to utilize such a known machine for coating very thin panels having a thickness as small as 0.035-0.05 mm since the panels are not fixed in their plane.

The object of the present invention is to eliminate the above-mentioned problems and to provide a machine which is loaded and unloaded at the inlet and outlet ends in an automatic way and which can also be utilized for very thin panels.

The machine in accordance with the invention is characterized in that the machine, which is protected from external light, comprises a loading station for automatic loading of panels and an unloading station for automatic unloading of treated panels; in that the loading station comprises a feeding device and a transfer device, which devices co-operate with each other to feed and transfer a panel or several separate panels to said transportation loop, which transfer device comprises

- a vertical-carriage, movable along a vertical part of said transportation loop and arranged to be moved to a lower transfer position whilst carrying a transportation bracket with panel carriers, and

- a transfer table, pivotably journalled for setting in a horizontal position and in a vertical position and arranged to be moved in a vertical position with panels to said transfer position of the vertical-carriage to transfer the panels to the panel carriers of the same; in that the unloading station comprises a transfer device and a feeding out device, which devices co-operate with each other to transfer and feed out a panel or several separate panels from said transportation loop, which transfer device comprises

- a vertical-carriage, movable along part of said transportation loop and arranged to be moved to a lower transfer position whilst carrying a transportation bracket with panel carriers, and

- a transfer table, pivotably journalled for setting in a horizontal position and in a vertical position and arranged to be moved in a vertical position with panels from said transfer position of the vertical-carriage to transfer the panels from the panel carriers of the same to the feeding out device; and in that each panel carrier is provided with first holding members, for detachably holding each panel by its upper edge section and for forming electrical connection points, and second holding members for detachably holding each panel by its two lateral edge sections.

The invention is further described in the following with reference to the drawings .

Figure 1 shows schematically in a side view and partially in X-ray view a machine in accordance with a currently preferred embodiment of the invention.

Figure 2 is a side view of an upstream part of the machine .

Figure 3 is an end view of the inlet end of the machine.

Figure 4 is an enlarged end view of parts of the inlet end of the machine in accordance with Figure 3.

Figure 5 is a cross section of part of an electro depositing station in the machine.

Figure 6 is a sectional view of the machine and shows a blowing station.

Figure 7 shows the blowing station in accordance with Figure 6 from one side of the machine. Figure 8 is a sectional view of the machine and shows a drying station.

Figure 9 shows the drying station in accordance with Figure 8 from one side of the machine with the front sections removed.

Figure 10 is a side view of a downstream part of the machine.

Figure 11 is an end view of the outlet end of the machine .

Figure 1 shows schematically a machine for fully- automatic manufacturing of an electrophoretic coating on a panel-like plate-shaped object 1, which is electrically conductive. Electro deposition of a photoresist is an electrochemical process consisting of three distinct steps, namely electrophoresis, electrolysis and electro osmosis. The panels can consist of a laminate having a non-conductive carrier layer and a copper foil on one or both sides of the carrier layer. A conductive pattern is created on the panels by etching, after a so-called resist has been deposited onto the copper foil, which resist constitutes a coating resistant to the etching liquid, to obtain a desired conductive pattern, which is exposed after the etching by removing the resist . By depositing a resist film by electrophoretic means, it is possible to make the width of the conductors and the spaces between the conductive parts in the conductive pattern considerably smaller than by using a method in which a film of light-sensitive resist material is rolled onto the copper foil. In the machine in accordance with the invention, the panel serves as an electrode in an electrically conductive bath containing the light-sensitive resist material in ion form. Accordingly, the machine is enclosed in a room, which is protected from external light, which room is defined by suitable walls and ceiling. The machine has a synchronized transportation system and a computerized control and surveillance system, which is linked to the transportation system, to sequentially move groups of several panels through the machine with pre-determined dwell times for the different treatment procedures.

The machine comprises an elongate stand 2 with an inlet end 3 and an outlet end 4. A loading station 5 for automatic loading of untreated panels is located at the inlet end 3 and an unloading station 6 for automatic unloading of the treated panels at the outlet end 4. A treatment line, along which the panels are subjected to a series of different treatments, extends between the loading station 5 and the unloading station 6. The treatment line comprises a first treatment section 7, a second treatment section 8 and a third treatment section 9. The panels are moved in groups, with three panels in each group in the embodiment of the machine shown, the panels in each group assuming a vertical position and extending in one and the same plane, which is perpendicular to the machine direction.

The first and third treatment sections 7, 9 comprise a plurality of equiform, elongate receptacles 10 that are placed closely adjacent to each other and are upwardly open. The receptacles 10 extend across the machine direction. Thanks to the position of the panels during movement, i.e. in a common vertical plane across the machine direction, the receptacles can be made relatively narrow with consequent reduced machine length. A vertical-carriage 11, which is movable upwards and downwards, is located behind each receptacle 10. The vertical-carriage 11 has a flat plate 12 with wheels 13, running in vertical guide rails 14 that are fixedly mounted on the machine stand 2. A pair of vertically arranged power cylinders are connected to back side of the plate 12 of the vertical-carriage 11 to move the vertical -carriage 11 up and down and to lock the vertical-carriage in desired positions, a pneumatic cylinder 15 being responsible for said movement and a hydraulic cylinder (not shown) being responsible for the locking. The plate 12 of the vertical-carriage 11 is provided with a support and suspension device 16 (see Figure 2) , which is fixedly mounted on the upper end section of the front side of the plate 12, the front side facing the receptacle 10. The support and suspension device 16 comprises an upper horizontal angle rail 17 and a support rail 22 below the same. The vertical-carriage 11 is moved with the aid of the pneumatic cylinder 15 between an upper end position and a lower end position to be set in these end positions and certain determined positions therebetween with the aid of said hydraulic cylinder (not shown) . In the upper end position of the vertical-carriage 11, said angle rail 17 forms part of a first horizontal transportation route or transportation line, extending within each of the first, second and third treatment sections 7, 8, 9 and, as regards these, at the same level. In the locality of the second treatment section 8, a continuous angle rail 109 constitutes part of said transportation line, the angle rail 109 being fixedly mounted on a plate, which is in turn fixedly mounted on the machine stand and which is also provided with a support rail 110, having the same function as the support rails 22 of the vertical-carriages 11. A horizontal beam 18 is mounted on the machine stand 2, immediately above this horizontal transportation line, and supports a movable rod 19. The rod 19 is journalled in the beam 18 for reciprocating motion and carries a plurality of pushers 20 corresponding to the number of vertical-carriages 11. Each pusher 20 is arranged in the locality of its respective vertical -carriage 11. The movement of the rod 19 with pushers 20 is effected with the aid of an actuator 21, suitably a motor-driven ball screw.

The machine comprises a plurality of panel carriers 28 (see Figure 3) and a corresponding number of transportation brackets 29, in the embodiment shown 20, which are horizontally movable and arranged to be suspended in the support and suspension devices 16 of the vertical-carriages 11 that are vertically movable. Each transportation bracket 29 is for this purpose provided with a horizontal -carriage 30 with upper and lower, carrying and supporting sets of wheels 31, 32 which co-operate with, respectively, the horizontal angle rail 17 on its vertical inside and the horizontal support rail 22 of the vertical -carriage 11. The transportation bracket 29 has a lower, horizontal suspension arm 33, provided with a plurality of angular suspension hooks 34, which are fixedly mounted on the suspension arm 33 and extend downwards from its underside to a position along a common horizontal line. The transportation bracket 29 further has an upper sloping brace 35 to support the suspension arm 33, which brace 35 is fixedly mounted to the horizontal-carriage 30 and the suspension arm 33.

A transportation bracket 29 is pulled across from one vertical-carriage 11 to the immediately following vertical-carriage 11, with the aid of said pushers 20 on the horizontal rod 19, when the angle rails 17 of the two vertical-carriages 11 are aligned with each other and, consequently, the vertical-carriages 11 are in their upper end positions. This horizontal movement is thus made possible with the aid of the horizontal-carriage 30 of the transportation bracket 29.

In the proximity of each vertical -carriage 11 and centred on the same, there is a position transducer 53 for detecting the presence of a transportation bracket 29, when the same has been transferred from the immediately preceding vertical-carriage 11. The transportation bracket 29 with its carriage is retained in the desired position on the vertical-carriage 11 with the aid of a suitable friction brake (not shown) .

In the first treatment section 7, the following treatments are executed in the sequentially arranged receptacles 10: cleaning of the panels 1 with suitable cleaning fluid; rinsing in two receptacles; micro-etching; rinsing in two receptacles; pre-wetting of the panels with a solution for electro deposition; precipitation from a solution for electro deposition of an electrophoretic resistant coating on the panels and any void walls in the panels; rinsing in two receptacles with a special rinsing solution; rinsing in two receptacles; and air-blowing. In the second treatment section 8, the panels are dried along a distance corresponding to the length of six receptacles in the first treatment section 7. In the third treatment section 9, the panels are cooled with surrounding air in two receptacles to a desired temperature.

Said first horizontal transportation line is located in the lower part of the machine. The machine also has an upper part or floor, having a second transportation line of the same length as the first one. In the area of the loading and unloading stations 5, 6, the first and second transportation lines are connected with each other by vertical transportation lines, which four transportation lines form a closed loop for transporting the transportation brackets 29 with panel carriers 28 in a circuit. Each vertical transportation line is formed by vertical guide rails 90 and 91, respectively (Figure 1) , extending from the base of the machine to its top, and by a vertical-carriage 23 and 24, respectively, of the same design as the vertical-carriages 11 described above, which vertical-carriage 23, 24 runs in the guide rails 90, 91. A pair of vertically arranged power cylinders are connected to the rear side of the plate of the vertical-carriage 23, 24 to move the vertical-carriage 23, 24 up and down and to lock the same in desired positions. A motor-driven ball screw 92 effects said movement, its motor being provided with a brake. The upper floor accommodates a reconditioning section for the panel carriers 28, comprising four elongate receptacles

93 that are placed closely adjacent to each other and are upwardly open. The receptacles 93 extend across the machine direction. Behind each receptacle 93 there is a vertical-carriage 94 of substantially the same design and arranged in substantially the same way as the vertical-carriages 11 located in the lower part of the machine. In the upper end position of the vertical-carriage 94, its angle rail 95 (Figure 3) forms part of said second horizontal transportation line. Immediately above the same, a horizontal beam is mounted on the machine stand 2 and supports a movable rod 97. The rod 97 is journalled in the beam for reciprocating motion and carries a plurality of pushers 98 arranged in the locality of the vertical-carriages 94 and upstream of the same. The rod 97 with pushers 98 is moved with the aid of an actuator, suitably a motor-driven ball screw. The transportation line before and after the vertical-carriages 94 is formed by continuous angle rails. Downstream of the vertical-carriages 94, the reconditioned panel carriers and transportation brackets are moved forward with the aid of a motor-driven linear unit 99 with a cogged belt.

The panel carriers 28 comprise a horizontal yoke 36 having a straight, elongate shape and a square cross section, which yoke 36 can be freely suspended from the suspension hooks 34 of the transportation bracket 29 enabling easy receipt and release from the yoke 36 at different locations in the machine. The yoke 36 is turned about its longitudinal axis in such a way that its long sides form an angle of 45° with the horizontal plane. The suspension hooks 34 have two inner support surfaces that are correspondingly angled to receive the yoke 36. The suspension of the panel carriers 28 is thereby efficiently stabilized against oscillation. Further, the panel carrier 28 comprises a first holding member 37, which is electrically conductive, and a second holding member 38 for efficient holding of each panel 1 to be carried by the panel carrier. The holding members 37, 38 are designed to be able to hold thin panels (0.035-0.05 mm) as well as thick panels and, moreover, panels of different sizes. The first holding member 37 is arranged to hold a panel by its upper, horizontal edge portion. In the embodiment shown, the first holding member 37 comprises three tongs-like top clamps 39 (see Figures 2, 3 and 7) that are fixedly and rigidly mounted on the yoke 36, via individual mounting plates 40. Each top clamp 39 has two co-operating jaws 41, 42, of which the one jaw 41 is fixedly and rigidly connected to said mounting plate 40 and extends vertically downwards, whilst the other jaw 42 is pivotably journalled to the fixed jaw 41 about a horizontal pin 43. The top clamp 39 is kept in a closed position by means of a spring (not shown), acting between the upper, i.e. the rear end sections of the jaws 41, 42. At their lower ends, the jaws 41, 42 are provided with special contact elements 45, which form between them a gap that is opened when the pivotable jaw 42 is influenced by an external force, applied to the upper end of the jaw 42 and overcoming the spring load. The contact elements 45 have edge-like ridges, the apexes of which are brought into engagement with the panel 1 to secure efficient current-carrying connection between panel 1 and contact element 45. The second holding member 38 is arranged to hold the panel 1 by its two vertical edge sections. In the embodiment shown, the second holding members 38 comprises four vertical, equidistantly arranged mounting legs 46 (see Figures 4 and 7) that are fixedly and rigidly connected to said mounting plate 40. For each panel 1, there are four lateral clamps 47, arranged in pairs for each vertical lateral edge of the panel. The lateral clamps 47 are fixedly arranged on said mounting leg 46 and have their individual clamping arms fixedly connected to a vertical, pivotably journalled rod 48. At its upper end, each rod 48, which thus is rigidly connected to two clamping arms, carries a small toothed wheel, which is in toothed engagement with a horizontal rack 105 (see Figure 7) in a spring-loaded mechanism 49 for opening and closing the lateral clamps 47, the rack 105 having a free impact head 50 to be influenced by an external force. In their closed positions, the clamping arms of the lateral clamps 47 clamp the vertical lateral edges of the panel 1 to the fixed support parts of the lateral clamps 47, which support parts are fixedly arranged on the mounting legs 46. The combination of top and lateral clamps 39, 47 results in a very stable holding of each panel so that the same is maintained in a vertical position throughout and without being deflected under the influence of the mediums with which the panel is being treated in the different sections.

The loading station 5 comprises a feeding device and a transfer device, which devices co-operate with each other. The feeding device has a horizontal feeding table 54 (see Figures 2, 3, 4), on which untreated panels are automatically placed from, for instance, a hopper or from a conveyor belt in a preceding machine of a different kind. The transfer device has a pivotable and horizontally displaceable transfer table 55. The horizontal feeding table 54 is telescopically extendible in its feeding direction to form an extended inserted part 56, arranged to assume a position immediately above the transfer table 55 when a panel is being loaded. The feeding table 54 consists of a belt conveyor. The transfer table 55 extends across the machine direction and has a length suited to a pre-determined number of panels 1 placed next to each other. In the embodiment shown, the transfer table 55 is designed to carry three panels placed horizontally one after the other. The feeding device further comprises a transverse conveyor 57, which has a vertically adjustable carrying plate 58 with a plurality of downwardly-facing suction cups 59 and is movable along the transfer table 55. The carrying plate 58 is raised and lowered by means of four pneumatic cylinders 52. The transverse conveyor 57 is journalled to slide on a horizontal rail 108 and is moved back and forth along the same by means of a belt 100, which is driven by a motor 101 (Figure 4) . When a panel is loaded and rests on the extended belt-conveyor part, the carrying plate 58 is lowered, by means of the pneumatic cylinders 52, towards the panel and seizes the same with the aid of the suction cups 59. The carrying plate 58 lifts the panel up, whereupon the transverse conveyor 57 moves this first panel to the furthest position on the transfer table 55. A second loaded panel is then placed adjacent to the first panel, while the third loaded panel keeps its position as loaded and is placed on the transfer table 55 after the panel has been lifted by the carrying plate 58 with suction cups 59 and the extended belt-conveyor part 56 has been moved back to an initial position beyond the transfer table 55. The transfer table 55 is provided with a plurality of clamping devices 60 that can be set in an open position and in a closed position, in which closed position they press against support surfaces on the transfer table 55 with a certain clamping force. The clamping devices 60, which are actuated by pneumatic cylinders 61, are arranged at the upstream end of the transfer table 55 and are retracted from its plane during the loading procedure to be activated in due succession after each panel has been lowered to clamp the three panels 1 to the transfer table 55. The transfer table 55 is carried at both its ends by stands 62, provided with carriages 64 running along horizontal rails 65. The rails 65 are arranged on both sides of the machine and extend up to a point aligned with said vertical-carriage 23, which forms part of the transfer device. The carriages 64 with appurtenant stands 62 and transfer table 55 are moved back and forth along the rails by means of motor-driven belts 102. The transfer table 55 is pivotably journalled at its ends on the stands 62 about horizontal shafts 103, extending across the machine direction (Figure 2) , and is manipulated by two pneumatic cylinders 104 to be pivoted between a horizontal position and a downward-turned, vertical position. (Both these positions are shown in Figure 2) . When the three panels have been clamped to the transfer table 55 with the aid of the clamping devices

60, the transfer table 55 with the panels is pivoted down to a vertical position and moved along the rails 65 to a position aligned with the vertical-carriage 23, which is now located in its lowest position with its panel carriers 28 in an open receiving position to receive the panels 1 from the transfer table 55, i.e. all top and lateral clamps 39, 47 are turned to opened positions. For this purpose, the transfer device has an opening-and-closing mechanism 66 , arranged to open and close the top clamps 39 and the lateral clamps 47. The mechanism 66 comprises two or more pneumatic cylinders 67, the piston-rods of which carry a first impact member 68 in the shape of a bent sheet-metal section to influence the opposite, contact-forming top clamps 39 and a plurality of other impact members 69 to influence the impact heads 50 of the racks 105, which in turn influence the lateral clamps 47 via the shafts 48. The second impact members 69 are fixedly mounted on the first impact member 68. On activation of the first and second impact members 68, 69, which takes place when the panel holder 28 is in its lowest position to receive the panels 1 from the transfer table 55, the top and lateral clamps 39, 47 are caused to open. The transfer table 55 assumes a lower position when it reaches the vertical-carriage 23 so that the panels at this stage are free from lateral contact with the top clamps 39. When these have been opened, the transfer table 55 is raised a short distance by means of pneumatic cylinders (not shown) so that the top edges of the panels become located inside the gaps of the opened top clamps 39. When the impact members 68, 69 of the pneumatic cylinders 67 are returned to their inactive initial position, the top and lateral clamps 39, 47 are closed so that the panels are clamped at their top and lateral edges. Thus, the panels cannot be deflected in a horizontal direction when they are subjected to lateral forces from the gases and liquids used in the subsequent treatment sections 7, 8, 9, but will preserve their flat shape in a favourable way to obtain optimal treatment results throughout the process line. The vertical-carriage 23 is then moved to a waiting position to transfer the transportation bracket 29 and its panel carriers 28 with untreated panels to the first vertical-carriage 11. The transfer table 55 is simultaneously returned to the feeding device for a fresh load of three panels.

The first treatment section 7 has an electro deposition station 70 (see Figure 5) for precipitating an electrophoretic resistant coating on both sides of the panel, which electro deposition station 70 comprises a device 71 for transmitting motion (see Figure 1) , on which the yoke 36 of a panel carrier 28 is placed, whilst the suspension hooks 34 of the transportation bracket 29 are removed from engagement with the yoke 36. The motion-transmitting device 71 is insulated at the point of contact with the yoke 36 and is arranged to give the yoke 36 a horizontal reciprocating motion in the machine direction so that the panels, when located in the electro depositing bath, acquire a corresponding motion. The motion-transmitting device 71 is simultaneously arranged to oscillate the yoke 36 so that the panels also acquire an oscillating motion. Several of the other treatment stations can also be provided with similar devices for transmitting motion to give the panels a reciprocating motion when they are submerged in the respective receptacles 10. In the receptacle 10 in the electro deposition station 70, each panel acts as an electrode, usually an anode, the other electrode being formed by electrically conductive plates 96, arranged on both sides of the panels in the receptacle 10. The electrodes 1, 96 are connected to a suitable power source .

The first treatment section 7 further has a blowing station 72 (see Figures 6 and 7) , comprising a blowing device, arranged in the receptacle 10 and having a stand 73, which is movable across the machine direction and which, via a guided connection element 74, is carried by a piston-rod of a pneumatic cylinder 75, fixedly mounted on the bottom of the receptacle 10. The stand 73 comprises three upright pairs of arms 76, carrying blowing nozzles 77, connected to a compressed-air source (not shown) for a supply of clean, oil-free air. The arms 76 in each pair of arms define between them a space for receiving a panel. The vertical-carriage 11 located in the blowing station 72 is arranged to lift the panels out of the receptacle 10 in a slow smooth movement, while the blowing nozzles 77 are simultaneously moved to and fro in a slow movement. When the panels 1 are lifted completely out of the receptacle 10, air has been blown against both sides of each panel in a comprehensive way so that the panels are free of liquid. Blowing can take place, additionally or instead, when the panels are lowered into the receptacle, if so desired.

The second treatment section 8 comprises a drying chamber 25 (see Figures 8 and 9) with a closable inlet opening 26 and a closable outlet opening 27, which inlet and outlet openings 26, 27 are closable by means of controllable louvres 78, 79, which are connected via cords 80 to individual pneumatic cylinders 81 for raising the controllable louvres 78, 79 independently of each other, when a panel carrier 28 is being loaded into or out of the drying chamber 25, which can take place at different times. The drying chamber 25 is provided with a lower system of ducts 82 for blowing warm air into the drying chamber 25 and an upper system of ducts 83 for extracting air therefrom. The systems of ducts 82, 83 are connected to an outer system of pipes 106 for supplying warm, dry air and removing used air. The ducts of at least the system of ducts for blowing air into the drying chamber 25 have individually controllable adjustment members (not shown) for regulating the supply of air through each duct to secure optimal treatment of the panels in a comprehensive and uniform way. A panel-carrier transporter 84 extends through the drying chamber 25 and comprises a plurality of pushers 85 for advancing the panel carriers 28 step by step from a fetching point beyond and upstream of the drying chamber 25 to a delivery point beyond and downstream of the drying chamber 25. The pushers 85 are journalled for rocking on a reciprocating rod 86 on each side of the machine, which rod 86 is connected to and driven by an actuator 87, suitably a motor-driven ball screw. The yokes 36 of the panel carriers 28 are supported by and slide on suitable parallel sliding rails 88, while advancing through the drying chamber 25, as well as shortly before and after the same. At its upstream end, the panel-carrier transporter 84 has a rearward-facing pusher 89, which, like the first pusher 85, is pivotably journalled on the rod 86, a special plate 107 pivoting the pusher 89 to release the same during advancement, which pivoting is carried out with a pneumatic cylinder 111. The rearward-facing pusher 89 is arranged to move the yoke 36 rearwardly to provide free space for the suspension hooks 34 to move upwards during connection of the vertical-carriage 11. During the advancement movement of the rod 86, the rearward-facing pusher 89 is tilted down to an inactive position. When a panel carrier 28 has been delivered from a transportation bracket 29, the latter is lifted up by the vertical-carriage 11 to its upper position, from which the now empty transportation bracket 29 is advanced step by step to the downstream side of the drying chamber 25, where the vertical-carriage 11 receives the transportation bracket 29 and lowers the same to receive, yet again, its panel carrier 28, which in the meanwhile has passed through the drying chamber 25.

The unloading station 6 (see Figures 10 and 11) is in essence similar to the loading station 5 in structural respects, but operates in the reverse order. The unloading station 6 comprises a transfer device and a feeding out device. The feeding out device has a horizontal feeding out table 154, on which treated panels are received for delivery to a subsequent treatment unit (not shown) for exposure and development of the panels. The transfer device has a pivotable and horizontally displaceable transfer table 155. The feeding out table

154 is telescopically extendible in its machine direction to form an extended inserted part 156, arranged to assume a position immediately above the transfer table 155, when a panel is to be removed. The feeding out table 154 consists of a belt conveyor. The transfer table 155 is of the same length as the one in the loading station 5. The feeding out device further has a transverse conveyor 157 with a vertically adjustable carrying plate 158 and suction cups 159 facing downwards from the same. The carrying plate 158 is raised and lowered by means of four pneumatic cylinders 152. The transverse conveyor 157 is journalled to slide on a rail 208 and is moved back and forth along the same by means of a belt 200, which is driven by a motor 201. The transfer table 155 is provided with a plurality of clamping devices 160 that can be set in an open position and in a closed position, in which closed position they press against support surfaces on the transfer table 155 with a certain clamping force. The clamping devices 160, which are actuated by pneumatic cylinders 161, are arranged at the upstream end of the transfer table 155 and are retracted from its plane during the feeding out procedure. The transfer table 155 is carried at both its ends by stands 162 provided with carriages 164 running along horizontal rails 165. The rails 165 are arranged on both sides of the machine and extend up to a point beneath said vertical-carriage 24, which forms part of the transfer device. The carriages 164 with appurtenant stands 162 and transfer table 155 are moved back and forth along the rails by means of motor-driven belts 202. The transfer table 155 is pivotably journalled at its ends on the stands 162 about horizontal rods 203, extending across the machine direction, and is manipulated by two pneumatic cylinders 204 to be pivoted between a horizontal position and a downwardly-turned, vertical position. The transfer device has an opening-and-closing mechanism 166, arranged to open and close the top clamps 39 and the lateral clamps 47. The mechanism 166 comprises two or more pneumatic cylinders 167, the piston-rods of which carry a first impact member 168 in the shape of a bent sheet-metal section to influence the opposite top clamps 39 and a plurality of other impact members 169 to influence the impact heads 50 of the racks 105, which in turn influence the lateral clamps 47 via the rods 48. The second impact members 169 are fixedly mounted on the first impact member 168. On activation of the first and second impact members 168, 169, which takes place when the panel carrier 28 is in its lowest position to release the panels 1, the top and lateral clamps 39, 47 are caused to open. The vertical-carriage 24 with panel carriers 28 is moved down to its lowest position, where, at this stage, the downwardly-turned transfer table 155 is located to receive the three treated panels. The clamping devices 160 are activated to clamp the panels against the transfer table 155, whereupon said mechanisms 166 are activated to open the top and lateral clamps 39, 47 so that the transfer table 155, with now held panels, can be lowered a short distance so that the top edges of the panels are positioned beneath the top clamps 39. The transfer table 155 is then pivoted up to a horizontal position and moved to the feeding out device, where the first panel is fed out by the belt conveyor 154, after the clamping devices 160 have been deactivated and the panel has been lifted up to allow for the extension of the belt conveyor 154 to its fetching position beneath the panel, which is then lowered again to be received by the extended belt-conveyor part 156. The transverse conveyor 157 then fetches the other two panels in due succession.

Claims

C L A I M S

1. A machine for treating panel-like plate-shaped objects (1), containing electrically conductive material, with different mediums which comprise a chemical solution for electro deposition of an electrophoretic resistant coating on at least one side of the panel, which machine comprises an inlet end (3) , an outlet end (4) , a plurality of receptacles (10) for said treatment mediums, a vertical-carriage (11) arranged in connection with each receptacle (10) for movement up and down, a plurality of transportation brackets (29) with horizontal-carriages (30) for moving a transportation bracket (29) from one vertical-carriage (11) to an immediately following vertical-carriage (11) , a plurality of panel carriers (28) arranged to be carried by the transportation brackets (29) for carrying one or several panels (1) , and a plurality of transportation lines combined in a transportation loop for moving the transportation brackets (29) in a circuit: characterized in that the machine, which is protected from external light, comprises a loading station (5) for automatic loading of panels and an unloading station (6) for automatic unloading of treated panels; in that the loading station (5) comprises a feeding device and a transfer device, which devices co-operate with each other to feed and transfer a panel or several separate panels to said transportation loop, which transfer device comprises

- a vertical-carriage (23) , movable along a vertical part of said transportation loop and arranged to be moved to a lower transfer position whilst carrying a transportation bracket (29) with panel carriers (28) , and

- a transfer table (55) , pivotably journalled for setting in a horizontal position and in a vertical position and arranged to be moved in a vertical position with panels to said transfer position of the vertical-carriage (23) to transfer the panels to the panel carriers (28) of the same; in that the unloading station (6) comprises a transfer device and a feeding out device, which devices co-operate with each other to transfer and feed out a panel or several separate panels from said transportation loop, which transfer device comprises

- a vertical-carriage (24) , movable along a part of said transportation loop and arranged to be moved to a lower transfer position whilst carrying a transportation bracket (29) with panel carriers (28) , and - a transfer table (155) , pivotably journalled for setting in a horizontal position and in a vertical position and arranged to be moved in a vertical position with panels from said transfer position of the vertical-carriage (24) to transfer the panels from the panel carriers (28) of the same to the feeding out device; and in that each panel carrier (28) is provided with first holding members (37) for detachably holding each panel by its upper edge section and for forming electrical connection points, and second holding members (38) , for detachably holding each panel by its two lateral edge sections.

2. A machine as claimed in claim 1, characterized in that the panel carrier (28) comprises a horizontal yoke (36) , the first and second holding members (37, 38) being fixedly and rigidly mounted on the yoke (36) via mounting plates (40) .

3. A machine as claimed in claim 2, characterized in that the first holding member comprises a plurality of downwardly-directed, spring-loaded, tongs-like top clamps (39) with two co-operating jaws (41, 42) , the one jaw (41) being fixedly and rigidly attached to said mounting plate (40) and the other jaw (42) being pivotably journalled to the first fixed jaw (41) , which jaws (41, 42) are provided at their lower ends with electrically conductive contact elements (45) , forming between them a gap that can be opened to receive the upper edge of a panel (1) .

4. A machine as claimed in any one of claims 2 and 3, characterized in that the second holding member (38) comprises a plurality of vertical mounting legs (46) that are fixedly and rigidly attached to said mounting plate (40) ; at least one lateral clamp (47) for each vertical side of each panel (1) , which clamp has a fixed support part, fixedly mounted on the mounting leg (46) , and a movable clamping arm, fixedly attached to a pivotably journalled, vertical bar (48) ; and a spring-loaded mechanism (49) for opening and closing the lateral clamp (47) , via said bar (48) , through the influence of an external force and the removal of such an external force, respectively.

5. A machine as claimed in claim 4, characterized in that the spring-loaded mechanism (49) has a toothed wheel, carried by said bar (48) at its upper end, and a horizontal rack (105) , in toothed engagement with said toothed wheel, which rack (105) has a free impact head (50) to be influenced by said external force.

6. A machine as claimed in any one of claims 1-5, characterized in that the feeding device has a horizontal feeding table (54) ; in that the transfer table (55) extends across the machine direction and is of a length suited to a pre-determined number of panels placed next to each other; in that the feeding table (54) is telescopically extendible in its feeding direction, which coincides with the machine direction, to form an extended inserted part (56) , arranged to assume a position immediately above the transfer table (55) during the loading of a panel; and in that the feeding device comprises a transverse conveyor (57) having a vertically adjustable carrying plate (58) with a plurality of downwardly-facing suction cups (59) and being arranged to be moved relative to the transfer table (55) to place panels, retained by the suction cups (59), along the transfer table (55) .

7. A machine as claimed in claim 6, characterized in that the transfer table (55) is provided with a plurality of clamping devices (60) that can be set in an open position and in a closed position, in which closed position the clamping devices (60) are arranged to press against support surfaces on the transfer table (55) to clamp the panels therebetween; and in that the transfer table (55) is arranged to be pivotably carried at both its ends by stands (62) , provided with driven carriages (64) , which run along horizontal rails (65) extending in the machine direction up to a position aligned with said vertical-carriage (23) of the transfer device.

8. A machine as claimed in any one of claims 1-7, characterized in that the transfer device comprises an opening-and-closing mechanism (66) , arranged to open and close the holding member (37, 38) of a panel carrier (28) , carried by the vertical-carriage (23) , in its lowered position, to receive and thereafter hold the panels.

9. A machine as claimed in claim 8 in combination with any one of claims 4 and 5, characterized in that the opening-and-closing mechanism (66) comprises actuators (67) , carrying at least one first impact member (68) to influence the opposite top clamps (39) and at least one second impact member (69) to influence the impact heads (50) of said racks (105) , which in turn influence the lateral clamps (47) , which first and second impact members (68, 69) are arranged to be activated to open the top and lateral clamps (39, 47) when the panel carrier (28) is in its lowest position for receiving the panels from the transfer table (55) , the clamping devices (60) of which being arranged to be opened to release the panels .

10. A machine as claimed in any one of claims 6-9, characterized in that the feeding out device has a horizontal feeding out table (154) ; in that the transfer table (155) extends across the machine direction and is of a length suited to a pre-determined number of panels placed next to each other; in that the feeding out table (154) is telescopically extendible in its feeding direction, which coincides with the machine direction, to form an extended inserted part (156) , arranged to assume a position immediately above the transfer table (155) during the feeding out of a panel; and in that the feeding out device comprises a transverse conveyor (157) having a vertically adjustable carrying plate (158) with a plurality of downwardly-facing suction cups (159) and being arranged to be moved relative to the transfer table (155) to fetch treated panels, retained by the suction cups (159) , along the transfer table (155) .

11. A machine as claimed in claim 10, characterized in that the transfer table (155) is provided with a plurality of clamping devices (160) that can be set in an open position and in a closed position, in which closed position the clamping devices (160) are arranged to press against support surfaces on the transfer table (155) to clamp the panels therebetween; and in that the transfer table (155) is arranged to be pivotably carried at both its ends by stands (162) , provided with driven carriages (164) , which run along horizontal rails (165) extending in the machine direction from a position aligned with said vertical-carriage (24) of the transfer device.

12. A machine as claimed in any one of claims 10 and 11, characterized in that the transfer device comprises an opening-and-closing mechanism (166) , arranged to open and close the holding member (37, 38) of a panel carrier (28) , carried by the vertical-carriage (24) , in its lowered position, to deliver the panels to the transfer table (155) .

13. A machine as claimed in claim 12, characterized in that the opening-and-closing mechanism (166) comprises actuators (167) , carrying at least one first impact member (168) to influence the opposite top clamps (39) and at least one second impact member (169) to influence the impact heads (50) of said racks (105) , which in turn influence the lateral clamps (47) , which first and second impact members (168, 169) are arranged to be activated to open the top and lateral clamps (39, 47) when the panel carrier (28) is in its lowest position for delivering the panels to the transfer table (155) , the clamping devices (160) of which being arranged to be closed to hold the panels.

14. A machine as claimed in any one of claims 1-13, characterized in that it has a first treatment section

(7) with a blowing station (72) , which is arranged downstream of an electro deposition station (70) and comprises a blowing device, having a stand (73) that is movable across the machine direction and carries blowing nozzles (77) for treating the panels (1) on both sides with air, which blowing nozzles (77) are arranged to be moved horizontally to and fro by means of the movable stand, the vertical-carriage being arranged to be moved simultaneously in a vertical direction so that the sides of the panels are treated with air in a comprehensive way.

15. A machine as claimed in claim 14, characterized in that it has a second treatment station (8) with a drying chamber (25) for drying the panels (1) with warm air, which drying chamber (25) has inlet and outlet openings (26, 27) that can be closed by controllable louvres (78, 79), arranged to be raised and lowered independently of each other to admit and discharge panel carriers into and from the drying chamber (25) ; and in that the drying chamber (25) has systems of ducts (82, 83) for blowing in and extracting air, the ducts of at least the system of ducts (82) for blowing in air having individually controllable adjustment members for regulating the supply of air through each duct.

16. A machine as claimed in claim 15, characterized in that the drying chamber (25) is provided with a conveyor (84) for the panel carriers (28) that comprises two sliding rails (88) , arranged parallel to each other on the long sides of the machine to carry the ends of a yoke (36) on each panel carrier (28) , and a reciprocating bar (86) on each long side of the machine, carrying a plurality of rocker pushers (85) for advancing the panel carriers (28) step by step through the drying chamber (25) .

17. A machine as claimed in any one of claims 1-16, characterized in that the vertical -carriage (11) is provided with a support and suspension device (16) , comprising an upper horizontal angle rail (17) and a support rail (22) below the same, said angle rail (17) being arranged to form part of a first horizontal transportation line in said transportation loop when the vertical-carriage (11) is located in an upper end position; and in that a reciprocating rod (19) is arranged immediately above said first transportation line, which rod (19) carries a plurality of pushers (20) , each arranged in the locality of a vertical-carriage (11) for moving the transportation brackets (29) horizontally as aforesaid.

18. A machine as claimed in claim 17, characterized in that each transportation bracket (29) is provided with a horizontal -carriage (30) with upper and lower, carrying and supporting sets of wheels (31, 32) for co-operating with the angle rail (17) and the support rail (22) , respectively, of said support and suspension device (16) .

19. A machine as claimed in any one of claims 1-18, characterized in that each transportation bracket (29) , which extends across the machine direction, has a lower horizontal suspension arm (33) , provided with a plurality of suspension hooks (34) for carrying a panel carrier (28) in a freely raisable condition.

20. A machine as claimed in any one of claims 2-19, characterized in that the yoke (36) consists of an elongate square section and is turned about its longitudinal axis in such a way that its two downwardly-facing long sides form an angle of 45° with the horizontal; and in that the suspension hooks have two inner upwardly-facing support surfaces that are correspondingly angled to receive and carry the yoke (36) in a stable way without oscillation.