REGISTERING DEVICE IN A LAMINATING MACHINE

Abstract: A registering device in a laminating machine for applying a cover sheet (13) which is fed obliquely downwards from above against a base sheet (11) in a substantially horizontal feeding path, the cover sheet being pasted to the base sheet. The device comprises a rotatably mounted registering roller (20) which is mounted without play at the free end of an arm (16) pivotally mounted for vertical movement. The arm is yieldingly biased for pressing the registering roller against the engagement member.

Description: REGISTERING DEVICE IN A LAMINATING MACHINE The invention relates to a registering device in a laminating machine for applying a cover sheet which is fed obliquely downwards from above against a base sheet in a substantially horizontal feeding path, the cover sheet being pasted to the base sheet, said device comprising a rotatably mounted registering roller which can move vertically and is spring-biased against a stationary engagement member. Such lamination is effected in. order to produce a multilayer sheet wherein the several individual sheets are adapted to fulfil a predetermined function in the multilayer sheet. For example in the operation concerned, a. sheet of corrugated cardboard, whic shall be included as a construction element in a cardboard box, may be provided with a thinner sheet which has or later on is to be provided with proper printing. Then, the adjustment of the sheets, the registering, is important not only in order to impart to the product made from the multilayer sheet an acceptable appearance but also because it may follow from improper adjustment of the sheets that the surface coated with the paste, usually the upper side of the base sheet, may not be completely covered by the cover sheet at one edge or the other. As a consequence thereof the paste may be transferred by existing press and feed drums in the laminating machine to the thinner cover sheet and accordingly the appearance thereof may be unacceptable or the processing of the sheets in the machine may be seriously disturbed. In some cases, the adjustment of the sheets should be such that the sheets are disposed edge to edge, and in other cases, it is desired in order to facilitate further processing of the multilayer sheet, to have the thinner cover sheet projecting beyond the edge of the thicker base sheet so that the cover sheet can be utilized to adjust and fix the multilayer sheet, e.g. in a printing machine. There is a risk of misadjustment if the registering device does not operate reliably and accurately but also if the registering device allows the cover sheet to slide on the paste-coated and thus slippy surface of the base sheet. It is desired that the registering device comprises a small number of operating elements and can be built into the laminating machine without substantially increasing the construction length thereof or making the constructive embodiment thereof too complicated. This requirement is satisfied by a prior art registering device which forms part of the laminating machine according to SE-B-8102774-0 (publication No. 433,926). The registering device described therein comprises a registering roller which is rotatably mounted with play in the bearings on a cross shaft mounted for linear vertical movement over an adjustable distance towards and away from a stationary engagement member formed by a plate which extends upwards inclined to the feeding plane for the base sheets. The registering roller is spring-biased against the stationary engagement member. A laminating machine having this registering device operates substantially satisfactorily, but it has been found that the registering device limits the operating speed of the machine. The registering roller mounted with play in the bearings does not take exactly the same position on the cross shaft- each time a sheet passes over said roller? this means that the angular position of the bearing play varies from time to time. As a consequence thereof the precision of the registering will be jeopardized particularly when the operating speed of the laminating machine is increased. Moreover, the registering roller and the cross shaft on which said roller is mounted are exposed to exceptionally great wear due to the existing bearing play, which also contributes to decreasing the accuracy of the registering. From the decreased accuracy of the registering it follows that the continued processing of the multilayer sheet will be more difficult. In order to satisfy the demand for accuracy in the registering when using a simple and reliable registering device which can be built into a laminating machine in a compact manner, the device according to the invention has obtained the characteristics appearing from claim 1. As a consequence thereof the registering roller will always take a distinct position in each phase of the registering operation, and this very fact contributes to the registering taking place at great accuracy. However, there is also attained the further advantage that the registering roller can be located in an axial gap in the press and feed drums which are usually arranged immediately after the registering device to presa together and advance the laminated cover and base sheets, which provides further safety for a , high precision being maintained in the registering, because the cover sheet will get no possibility of sliding on the base sheet after registering before the laminated sheets after the registering having been effected, are gripped by the press and feed drums. In order to explain the invention in more detail reference is made to the accompanying drawings in which FIG. 1 is a vertical sectional view of a registering device according to the invention in one embodiment thereof disposed in a laminating machine shown fragmentarily only, FIG. 2 is a corresponding view of another embodiment of the registering device of the invention, FIG. 3 is a corresponding view of a third embodiment of the registering device of the invention, FIG. 4 is a side view of an embodiment of a plate 5 provided as engagement member for the roller, FIGS. 5 and 6 are corresponding side views of two other embodiments of the engagement plate,' and FIG. 7 is a diagrammatic side view of a conveyor for feeding.sheets through the laminating machine. 10 Referring first to FIG. 1, there is shown therein only a few parts of the laminating machine wherein the registering device of the invention may be provided. Thus, a substantially horizontal flat plate 10 is shown for supporting a base sheet 11 which is shown to be made 15 of corrugated cardboard. The base sheet is advanced on the plate 10 by means of feed drums from a lower feeder which contains a supply of base sheets 11 supplied one at a time to be fed through the laminating machine. The sheets are fed via a paste applying unit by means of 20 which the the base sheet 11 receives paste on the upper side thereof. The laminating machine also comprises a flat plate 12 which extends from above obliquely downwards towards the plate 10 and the purpose of which is to support a thinner cover sheet 13. The cover sheet 25 can be supplied from an upper feeder by means of feed drums, but is is also conceivable to place manually the cover sheets one at a time on the plate 12. The plates 10 and 12 besides can be constructed as conveyors with conveyor belts, conveyor ropes or driven conveyor 30 rollers. The laminating machine as far as the parts described are concerned, can be of a conventional construction. On ' a cross bar 14 in the frame of the laminating machine there is clamped or mounted in another way a 35 block 15 on which a bell crank 16 is mounted for r ' ^) swinging movement about a shaft 17. Between one arm of the bell crank and the block a pressure spring 18 is engaged to bias the bell crank in the counter-clockwise direction as seen in FIG. 1. The other arm of the bell crank supports at the free end thereof a cross shaft 19 on which a registering roller 20 is rotatably mounted. The registering roller is mounted without bearing play, and preferably the registering roller consists of the outer ball race of a ball bearing, the inner ball race being fixed to the shaft 19. In a preferred embodiment, several ball bearings are arranged in an array axially one beside the other on the shaft 19 either at each side of a single bell crank 16 or between two bell cranks. However, it should be noted that any other constructive embodiment can be adhered to, which satisfies the requirement of a bearing-free mounting of the registering roller. Under the bias of the spring 18, the registering roller 20 is pressed against a registering plate 21 which is mounted to the plate 10 and is flat and horizontal as is said latter plate. Preferably, the registering plate 21 is mounted such that it can be displaced horizontally towards and away from the registering roller 20 in order that the angular position of the engagement location of the roller on the registering plate 21 can be changed. An alternative position has been indicated by dot and dash lines in FIG. 1 wherein the registering plate 21 is displaced towards the right, which means that the registering roller then is swung to a somewhat lower position under the bias of the spring 18. The adjusted position of the registering plate 21 then determines the adjustment between the cover sheet 13 and the base sheet 11, i.e. it can be achieved by the adjustment of the registering plate 21 that the cover sheet 13 and the base sheet 11 will be positioned edge to edge or that the cover sheet 13 projects more or less beyond the leading edge of the base sheet 11. In FIG. 1, two press and feed drums 22 forming part of the laminating machine are shown, the upper drum being movable in a known manner towards and away from the lower drum and being spring-biased against the lower drum. The purpose of the press and feed drums is at one hand to press the cover sheet and the base sheet against each other so that the cover sheet will be " pasted to the upper ' side of the base sheet, coated with paste, and at the other hand to advance the multilayer sheet thus obtained through the laminating machine to a discharge unit. In the present case, the press and feed drums are made in sections w th, axial gaps between adjacent sections, and the registering roller 20 is disposed in such a gap. For satisfactory registering, several registering rollers should be provided mutually spaced laterally of the laminating machine, and these rollers are disposed each, in one of the gaps of the press and feed drums. By such an arrangement it is achieved that the laminating machine can be made very compact, particularly that the constructive length thereof can be kept short. However, as far as the operation of the registering device is concerned, this device can also be located completely outside the press and feed drums. When the cover sheet 13 has been fed downwards along the plate 12 until it is stopped at the leading edge thereof in the nip between the registering roller 20 and the registering plate 21, i.e. in the position shown in FIG. 1, the base sheet 11 is advanced towards the cover sheet and further against the registering roller 20, said roller being lifted against the bias of the spring 18 and the two sheets continue to move under the registering roller between this roller and the registering plate 21 to arrive later at the nip between the press and feed drums so as to be transferred through the laminating machine while the cover sheet 13 with the adjustment defined by the adjustment of the registering plate 21 is overlaid to the base sheet 11 and is pasted against the upper side thereof coated by paste, when the sheets laid one upon the other pass between the press and feed drums 22. Instead of the registering plate 21 being adjustable the shaft 17 can be adjustable horizontally in the lateral direction thereof for the same purpose while the registering plate 21 in that case is stationary. In the embodiment of the invention shown in FIG. 2, the registering plate 21 is replaced by a lower registering roller 23 which is rotatably mounted to an arm 24 which is supported by a cross shaft 25 in the laminating machine. In this case, the adjustment between the cover and base sheets is controlled by displacing the shaft 14 horizontally laterally of the shaft as mentioned in connection with FIG. 1, but also the shaft 25 can be correspondingly displaceable for the same purpose. In the embodiment of FIG. 2, the registering rollers 20 and 23 are arranged in a gap between sections of the press and feed drums 22. The embodiment of FIG. 2 operates principally in the same manner as the embodiment of FIG. 1. FIG. 3 discloses an embodiment wherein the registering roller 20 is arranged as the lower registering roller and is engaged with the roller 23, arranged as the upper registering roller, the shaft 26 of which in this case can be mounted directly in the laminating machine, because the two registering rollers are disposed outside the press and feed drums 22 which in the embodiment of FIG. 3 need not be arranged in sections but can extend without interruption over the width of the laminating machine. The longer transfer distance between the registering roller 20, 23 and the press and feed drums 22 in the embodiment of FIG. 3, however, can cause sliding between the cover and base sheets and thus inaccuracy in the registering, and therefore it is preferred that the registering rollers be mounted in the manner shown in FIGS. 1 and 2. However, principally, the embodiment of FIG. 3 operates in the same manner as the embodiments of FIGS. 1 and 2. Instead of biasing the registering roller by means of a spring as in the embodiments described, this roller can be biased by a weight. Important is that the registering roller is yieldingly biased. In order to take into account varying character and quality of the material the registering plate can be constructed as shown in any of FIGS. 4 to 6. Then, the registering plate forms a shallow groove 27, FIG. 4, a shallow recess 28, FIG. 5, or a rib 29, FIG. 6, so that the registering roller 23 can be brought to take different positions in dependence on the displaced relative position of the registering roller and the registering plate as indicated by dot and dash lines. As mentioned above, the plates 10 and 12 can be constructed as conveyors, and FIG. 7 discloses such an embodiment. Rollers 30 are provided as end rollers for an endless belt 31 or several endless belts, and this belt or these belts engage support rollers 32. Between the rollers there are provided for the upper part of the belt or belts support plates 33 which are located below the level of the support and friction spots 34 on the roller 32. One or several of the rollers can be driven and the others be idling.

Claims: CLAIMS 1. Registering device in a laminating machine for applying a cover sheet (13) which is fed obliquely downwards from above against a base sheet (11) in a substantially horizontal feeding path, the cover sheet being pasted to the base sheet, said device comprising a rotatably mounted registering roller (20) which can move vertically and is spring-biased against a stationary engagement member (21; 23), c h a r a c t e r i z e d in that the registering roller (20) is mounted without play at the free end of an arm (16) pivotally mounted, which is yieldingly biased to press the registering roller against the engagement member. 2. Registering device as claimed in claim 1, c h a r a c t e r i z e d in that the registering roller (20) comprises the outer race of an anti-friction bearing or several anti-friction bearings mounted axially one beside the other. 3. Registering device as claimed in claim 1, c h a r a c t e r i z e d in that the engagement member comprises a substantially horizontally disposed plate (21). 4. Registering device as claimed in claim 3, c h a r a c t e r i z e d in that the plate (21A, 21B, 21C) is profiled to form grooves and/or raised portions which extend in parallel to the axis of the registering roller (23) and that the registering roller and the plate are relatively displaceable horizontally in the lateral direction of the axis of the registering roller. 5. Registering device as claimed in claim 3, c h a r a c t e r i z e d in that the registering roller (20) and the plate (21) are relatively displaceable horizontally in the transverse direction of the axis of the registering roller to change the angular position of the engagement spot between the registering roller and the plate on the periphery of the registering roller. 6. Registering device as claimed in claim 1, c h a r a c t e r i z e d in that the engagement member comprises a roller (23) rotatably mounted. 7. Registering device as claimed in claim 6, c h a r a c t e r i z e d in that the registering roller (20) and the roller (23) provided as the engagement member, are relatively displaceable horizontally in the lateral direction of the axis of the rollers to change the angular position of the engagement spot between the rollers. 8. Registering device as claimed in claim 1, c h a r a c t e r i z e d in that the registering roller (20) and the engagement member (21; 23) are arranged in an axial gap in a pair of drums (22) for pressing th'e cover and base sheets (13, 11) against each other after registering and following advancement of the composite sheet.

Inventors: LUNDING BO, LUNDING THORKILD, LUNDING, BO, LUNDING, THORKILD
Applicants: LUNDING BO, LUNDING THORKILD, LUNDING, BO, LUNDING, THORKILD
Application year: 1985
Main classification: B32B31
IPC codes: B65H39