EP0008666B1 - Device for applying covering sheets to plates - Google Patents

Abstract

1. Apparatus for covering plates, in particular chipboard, plywood, fibre board and the like with covering sheets of paper, felt, plastics and the like, the covering sheets being taken from piles and laid together with the plates, with a discontinuous conveyor track for the plates, a stack of covering sheets arranged above the conveyor track before the break, in the conveying direction, and a stock of covering sheets arranged below the conveyor track in the region of the break, characterized by a device (20, 21), which can be moved in a reciprocating manner in the conveying direction in the region of the break (10) and above the latter, for gripping and individual covering sheet (8 or 13) with suction nozzles (22) which are movable perpendicular to the conveying direction and are movable relative to the device (20) in a plane parallel to the plate, and by a holding device (39) in the region of the conveyor track (5) following the break (10).

Description

The invention relates to a system for covering boards, in particular chipboard, plywood, fiberboard and the like, with lamination sheets made of paper, felt, plastic and the like, the lamination sheets being removed from stacks and folded together with the boards, with an interrupted transport path for the boards, one in the transport direction before the interruption above and a stack of laminating sheets arranged in the region of the interruption below the transport path.

In the course of the production of laminated panels, the panels are first folded together with laminating sheets and then pressed together with this, if necessary, using heat. When laminating smaller panels, the lamination material is often pulled off the reels, placed on the panels and then cut to the appropriate length. However, this leads to problems when laminating very large panels. Therefore, to laminate very large panels, the laminating sheets are first cut and stacked and then folded together with the panels. This is done on a system of the type described above. Because the lamination sheets are very bulky, damage or destruction of the lamination sheets cannot be ruled out during manipulation.

The invention is therefore based on the object of specifying a system of the type described at the outset which operates largely automatically and without problems.

This object is achieved with a system of the type described at the outset, which is characterized by a device which can be moved back and forth in the region of the interruption and beyond in the transport direction, for detecting a respective lamination sheet with suction nozzles movable perpendicular to the transport direction, which are relative to the device in one are movable to the plane parallel to the plane of the plate, and by a holding device in the region of the transport path behind the interruption.

The plates arriving on the transport path are first stopped before the interruption. The device is moved over the interruption and its suction nozzles are set down on the lamination sheet stack located below the transport path. The suction nozzles capture the front end of the uppermost lamination sheet and pull it away from the stack, the front end being simultaneously raised to the level of the transport path and placed on the transport path section following the interruption. There the front end of the laminating sheet coming from the lower stack is held with the holding device. Then the plate located on the transport path before the interruption is moved over the interruption to the subsequent transport path section into the area of the holding device, while at the same time or thereafter the device is moved over the stack located above the transport path. The device then uses the suction nozzles to pull the top lamination sheet off the top stack and guide it onto the top of the plate up to the area of the holding device. In order to avoid subsequent alignment of the lamination sheets after being folded together with the plate, the suction nozzles can be moved relative to the device in a plane parallel to the plate plane. This allows the liner sheets to be aligned with the device as they are pulled from the stack. When the plates are moved further, they take their upper and lower lamination sheets with them so that everything can then be pressed together.

The suction nozzles are advantageously arranged on a suction bar which has one or more drives for horizontal displacement in the transport plane. The drives of the suction bar can be spindle drives or pneumatic or hydraulic drives, the spindles being articulated on the suction bar and their drives possibly articulated on the device and the drive acting transversely to the direction of transport engaging an abutment in the area of the center of the suction bar and two each in the area of the squeegee ends, drives which act on them and act in the transport direction are provided.

The suction bar with the suction nozzles, which can be lowered down to the lamination sheet stack, can advantageously have air nozzles at their ends, the outlet jet of which is directed under the assigned edge of the lamination sheet which is respectively gripped by the suction bar. The squeegee only detects the front end of the respective lamination sheet, which can be raised with it. However, since adhesive forces act between the stacked lamination sheets, which can cause the lamination sheet captured by the suction nozzles to fall off again, an air jet is blown under the recorded lamination sheet by the air nozzles connected to the end of the suction strip, which forms an air cushion underneath which forms the adhesive forces between the stack and the top lamination sheet releases and supports the holding forces of the suction nozzles.

The lamination sheets are generally cut with small tolerances with regard to the plate size. In order to achieve precise alignment of the lamination sheet and plates, it can be two-fold if the drives of the squeegee are controlled automatically will. For this purpose, it is proposed according to the invention that at least three photocells with assigned light sources are attached to the device as signal detectors and are arranged such that they detect assigned edges of the laminating sheet, and that the signal detectors or the photocells are connected in a control circuit, the actuators of which drive the Suagleiste are. The arrangement of the signal detectors or the photocells can be adapted to the given circumstances. It is only necessary to ensure that an angular and positional alignment of the detected laminating sheet is possible. In particular, two signal detectors can be arranged so that they detect the front edge of the lamination sheet, while a third detects a side edge of the lamination sheet.

Because of the size of the lamination sheets, their strength is extremely small in relation to the length and width. For this reason, the lamination sheets easily follow all movements of the squeegee, particularly in the vertical direction. However, it can happen that the lamination sheets removed from the stack located above the transport path automatically slip off the stack when a certain partial length has been withdrawn from the stack. To prevent this, it is advisable to arrange a support plate with adjustable height and inclination below the path of movement of a lamination sheet pulled off the upper stack, which has a plurality of recesses connected to a vacuum source on its side facing the lamination sheet. Due to the negative pressure, the lamination sheet is sucked onto the support plate, which can optionally be curved following the path of movement, and is thereby braked. To increase the braking effect, the recesses can be covered with a textile web, which also filters the intake air and thereby protects the vacuum source.

The braking action of the support plate can also be controlled by connecting the recesses one behind the other in the direction of movement to form a group and connecting each group to the vacuum source via a separately adjustable control valve. If necessary, appropriate adjustment of the individual control valves can influence the alignment of the lamination sheet relative to the plate.

The holding device can be a clamping bar that can be lowered onto the transport path. In particular, it can be a pivotable clamping bar that is lowered onto the lamination sheet removed from the lower stack to hold it and clamps it between itself and the transport path, which can be a transport belt. In the lowered position, the clamping bar can also serve as a stop for the plate that has been moved over the interruption. When the front end of the lamination sheet removed from the upper stack is placed on the plate, the lamination sheet and plate can be pressed against the transport path with one or more pressure rollers which can be lowered independently of the suction bar, so that they can no longer shift relative to one another during further transport.

In addition, one or more movable eccentric brackets can be provided, which brake the lamination sheets before they are braked by the negative pressure acting on the support plate. These eccentric brackets can be controlled, optionally by the device with the suction bar.

• Fig. 1 in schematischer Darstellung teilweise ein Seitenansicht einer Anlage zum Belegen von Platten mit Kaschierbogen,
• Fig. 2 teilweise in Seitenansicht eine Vorrichtung zum Erfassen und Aufnehmen eines Kaschierbogens von einem Stapel,
• Fig. 3 schematische eine Draufsicht in Richtung 111 auf einen Teil des Gegenstandes nach Fig. 1,
• Fig. 4 schematische eine Ansicht in Richtung des Pfeils IV auf einen Teil des Gegenstandes nach Fig. 2,
• Fig. 5 eine Ansicht in Richtung des Pfeils V auf einen Teil des Gegenstandes nach Fig. 2,
• Fig. 6 eine andere Betriebsstellung des Gegenstandes nach Fig. 5,
• Fig. 7 teilweise den Gegenstand nach Fig. 1 nach dem Auflegen des unteren Kaschierbogens auf die weiterführende Transportbahn,
• Fig. 8 den Gegenstand nach Fig. 7 nach Heranführen der Platte,
• Fig. 9 den Gegenstand nach Fig. 8 mit der Vorichtung nach Fig. 2 nach dem Auflegen des oberen Kaschierbogens,
• Figure 10 den Gegenstand nach Fig. 9 in anderer Funktionsstellung.

In the following an embodiment of the invention shown in the drawing is explained; show it:

• 1 is a schematic representation of a partial side view of a system for covering panels with laminating sheets,
• 2 partially in side view a device for capturing and receiving a laminating sheet from a stack,
• 3 shows a schematic plan view in the direction 111 of a part of the object according to FIG. 1,
• 4 is a schematic view in the direction of arrow IV of a part of the object according to FIG. 2,
• 5 is a view in the direction of arrow V on part of the object of FIG. 2,
• 6 shows another operating position of the object according to FIG. 5,
• 7 partly the object according to FIG. 1 after the lower lamination sheet has been placed on the further transport path,
• 8 shows the object according to FIG. 7 after the plate has been brought up,
• 9 shows the object according to FIG. 8 with the device according to FIG. 2 after placing the upper laminating sheet,
• Figure 10 the object of FIG. 9 in a different functional position.

The system shown in the drawing is used for covering large-area panels on both sides, in particular chipboard, plywood panels, fiberboard and the like with cut laminating sheets made of paper, felt, plastic and the like. The system includes a conveyor belt 1 on which plates 2 are brought up to the area of the end 3 of the conveyor belt in the direction of transport 4. At a certain distance from the end 3 of the conveyor belt 1, a further conveyor belt 5 is arranged in the transport direction 4, on which the plates 2 covered with laminating sheets are transported further. Both conveyor belts 1 and 5 form an interrupted transport path.

Below the conveyor belt 1 there is a pallet 6 with a stack 7 of cut laminating sheets 8. The pallet 6 is arranged such that its front end 9 extends into the area below the interruption 10 the transport track protrudes. The underside of the plates 2 is to be covered with the laminating sheets 8 stacked on the lower pallet 6.

Above the transport track 1 there is another pallet 11 with a stack 12 of laminating sheets 13, with which the top side of the plates 2 is to be covered.

Rails 14 are arranged above the interruption 10 and extend over the entire length of the interruption 10 and over part of the conveyor belts 1 and 5. On the rails, a carriage 18 can be moved back and forth between stops 15, 16 with rollers 17, which carries a device with which the laminating sheets are guided from the stacks 7 and 12 to the corresponding sides of the plate 2.

The carriage 18 has vertical guides for lifting rods 19 which carry at their lower end a bearing body 20 which can be connected to a lifting device, not shown, e.g. a cable, a lifting cylinder or the like, relative to the carriage 18 can be raised and lowered. Under the bearing body 20 there is a suction bar 21 with a row of suction nozzles 22 which are connected via a suction line 23 to a blower 24 arranged on the carriage 18. The suction bar 21 is held under the bearing body 20 so that it can move in a plane parallel to the plane of the plate. This is readily apparent from a comparison of FIGS. 2 and 4. Drives are arranged under the bearing body 20 in the transport direction 4 behind the suction bar 21, with which the suction bar can be moved in its plane. It is a spindle motor 25, the spindle 26 of which is articulated to a support arm 27 connected to the suction bar 21. The support arm 27 is attached approximately in the middle of the suction bar 21. With the spindle motor 25, the suction bar 21 can be moved in the direction of arrow 28 transversely to the transport direction. In the area of the ends of the suction bar 21, spindles 29, 30 are connected to these in an articulated manner, the associated spindle motors 31, 32 of which are also held under the bearing body 20. By actuating the spindle motors 31, 32, the suction bar 21 can be adjusted and / or pivoted in the direction of the arrows 33 and 34, respectively. All spindle motors 25, 31 and 32 are held under the bearing body 20 so as to be movable about vertical axes. Skids 35 are located on the underside of the motors, so that when the lamination sheets 8 or 13 are picked up, they do not come into contact with the motors.

The spindle motors 25, 31, 32 are actuators of a control crane, the control variable of which are supplied by photocells 36, which have associated light sources, not shown. Specifically, two photocells 36 are arranged in the transport direction in front of the bearing body 20 in the illustrated embodiment, which detect the front edge of the laminating sheet 8 or 13 and control the orientation of this edge, while another photocell, not shown, in the area of a lateral edge of the laminating sheet is arranged and controls the alignment of this side edge together with the other photocells.

The system shown works as follows: First, a plate 2 is moved up on the conveyor belt 1 until the front edge of the plate has reached the area of the end 3. Then the device for covering is moved over the interruption 10 and the bearing body 20 with the suction bar 21 is lowered to the lower stack 7. There, the suction nozzles 22 of the suction bar 21 capture the uppermost lamination sheet 8 in the region of its front edge. So that the lamination sheet 8 gripped by the suction nozzles does not fall down again, the suction strip has at its ends air nozzles 37, 38 (FIGS. 5, 6) which are bent downward from the suction nozzle and so that the jet emerging from them falls below the grips the lateral edge of the detected lamination sheet, releases the adhesive forces between the uppermost lamination sheet and the one below, and supports the suction forces of the suction nozzles.

The suction bar 21 with the lamination sheet 8 is then lifted up into the transport plane and guided over the conveyor belt 5 adjoining the interruption 10. There the front edge of the lamination sheet 8 is deposited and held in place with a pivotably mounted clamping bar 39 which is lowered onto the front edge of the lamination sheet 8 located on the conveyor belt 5 (FIG. 7).

Then the plate 2 is advanced in the transport direction 4 until it abuts the terminal block 39. The bearing body 20 with the suction bar 21 has meanwhile been raised and moved over the upper stack 12. There, the suction bar 21 is lowered over the front edge of the top lamination sheet 13. The uppermost lamination sheet 13 is taken up in the same way as the lamination sheet 8 from the lower stack 7. The device is then moved in the transport direction 4 and lowered until the front edge of the taken-up lamination sheet 13 is above the transport belt 5 and above the front edge of the sheet held laminating sheet 8 is located (Fig. 9).

It goes without saying that when the lamination sheets 8 and 13 are picked up and transported, the above-described control loop functions, so that the lamination sheets 8 and 13 are oriented as desired when they are placed on the conveyor belt 5 or on the plate 2.

So that the lamination sheet 13 removed from the upper stack 12 does not perform any uncontrolled own movements while the suction bar 21 brings its front edge into the area of the conveyor belt 5, a support plate 40 is arranged above the end 3 of the conveyor belt 2, the shape of which is shown in FIG Transport direction 4 of the developing shape of the lamination sheet 13 is adapted (Fig. 1). The support plate 40 is adjustable with respect to its height relative to the conveyor belt 2 and with regard to its inclination. On the side facing the lamination sheet 13, the support plate 40 has a plurality of recesses 41, 42, 43 which are covered with a continuous textile web 44. The recesses 41, 42 and 43 are connected via lines 45, 46, 47 to a vacuum source, in the exemplary embodiment shown a blower 48. All recesses 41, 42 and 43 lying one behind the other in the transport direction 4 are combined to form a group, the associated lines 45, 46, 47 of which have separately actuable control valves 49, 50, 51. By adjusting the control valves differently, the suction power of the recesses can be adjusted so that the alignment of the lamination sheet 13 with the suction bar 21 is supported. In addition, the suction power on the recesses is set so that the friction between the underside of the lamination sheet 13 and the textile web 44 prevents undesirable and uncontrollable movements of the lamination sheet 13.

When the plate 2 and the lamination sheets 8 and 13 are folded together in the desired manner, i.e. if their respective front edges are above or on the conveyor belt 5 (FIG. 9), a pressure roller 53 held on the carriage 18 with guide rods 52 is first lowered onto the overlying lamination sheet 13 until the lamination sheet and the plate together on the one hand and on the other hand the conveyor belt 5 can be pressed. The drive for lowering the pressure roller 53 is not shown. The pressure roller 53 thus holds the plate and the lamination sheet in the present assignment, so that the bearing body 20 can be raised with the suction bar 21 (FIG. 10). Now the conveyor belt 5 can be set in motion and the plate 2 moved with the lamination sheets 8 or 13 in the transport direction 4 e.g. forwarded to a press.

It goes without saying that the carriage 18 carrying the device for documenting is driven and that its drives can be controlled automatically, so that the described documenting of the plate 2 is carried out fully automatically.

Claims (12)

1. Apparatus for covering plates, in particular chipboard, plywood, fibre board and the like with covering sheets of paper, felt, plastics and the like, the covering sheets being taken from piles and laid together with the plates, with a discontinuous conveyor track for the plates, a stack of covering sheets arranged above the conveyor track before the break, in the conveying direction, and a stock of covering sheets arranged below the conveyor track in the region of the break, characterised by a device (20, 21), which can be moved in a reciprocating manner in the conveying direction in the region of the break (10) and above the latter, for gripping and individual covering sheet (8 or 13) with suction nozzles (22) which are movable perpendicular to the conveying direction and are movable relative to the device (20) in a plane parallel to the plate plane, and by a holding device (39) in the region of the conveyor track (5) following the break (10).

2. Apparatus according to claim 1, characterised in that the suction nozzles (22) are arranged on a suction bar (21) which comprises one or more of drives (25, 31, 32) for horizontal displacement in the conveying plane.

3. Apparatus according to claim 1 or 2, characterised in that the drives of the suction bar are spindle drives (25, 31, 32) or pneumatic or hydraulic drives, the spindles (26, 29, 30) being coupled in an articulated manner to the suction strip (21) and their drives optionally being coupled in articulated manner to the device (20), and the drive (25) operating transversely to the conveying direction acts upon an abutment (27) in the region of the centre of the suction bar (21), and two drives (31, 32) are provided respectively in the region of the suction bar ends, acting upon the latter and operating in the conveying direction.

4. Apparatus according to one of claims 1 to 3, characterised in that air nozzles (37, 38) are arranged at the ends of the suction bar (21), the emergent jets from which nozzles are directed below the associated edge of the covering sheet (8 or 13) below the associated edge of the covering sheet (8 or 13) gripped by the suction bar (21).

5. Apparatus according to one or more of claims 1 to 4, characterised in that on the device (20), as a signal source at least three photo cells (36) with associated light sources are provided and are arranged in such a way that they detect the associated edges of the covering sheets (8, 13), and that the signal sources or photo cells (36) are connected in a control loop of which the final control elements are the drives (25, 31, 32) of the suction bar (21).

6. Apparatus according to one or more of claims 1 to 5, characterised in that, below the path of motion of a covering sheet (13) taken from the upper pile (12), a support plate (40) with adjustable height and inclination is arranged which on its side facing the covering sheet (13) comprises a plurality of openings (41, 42, 43) connected to a suction source (48).

7. Apparatus according to one or more of claims 1 to 6, characterised in that the openings (41, 42, 43) lying one behind another in the direction of motion are combined to form a respective group, and each group is connected by means of a separately adjustable control valve (49, 50, 51) to the suction source (48).

7. Apparatus according to one or more of claims 1 to 6, characterised in that the openings (41, 42, 43) lying one behind another in the direction of motion are combined to form a respective group, and each group is connected by means of a separately adjustable control valve (49, 50, 51) to the suction source (48).

8. Apparatus acceding to one or more of claims 1 to 7, characterised in that the openings (41, 42, 43) are covered by a textile web (44).

9. Apparatus according to one or more of claims 1 to 8, characterised in that the retaining device is a clamping bar (39) which can be lowered onto the conveyor track (5).

10. Apparatus according to one or more of claims 1 to 9, characterised by one or more pressure rollers (53) which can be lowered independently of the suction bar (21).

11. Apparatus according to one or more of claims 1 to 10 characterised by one or more movable eccentric straps to retard the covering sheets (8 or 13), the movement of the eccentric straps being controllable optionally by the device (20).

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