Apparatus for re-orientating sheets

Abstract

 A conveyor apparatus for conveying sheets in a first direction and then in a second direction substantially perpendicular to the first direction has means (23, 24) for receiving sheets conveyed by a first conveying means (22) and for supplying said sheets conveyed by said first conveying means (22) to a second conveying means (31), said means for receiving and supplying including: a star wheel having an axially elongated hub (23), having a plurality of arms (24) extending radially from said hub and spaced circumferentially about said hub, said star wheel being mounted at a longitudinal end of said first conveyor means (22), a longitudinal axis of said hub being disposed substantially transverse to said first direction so as to receive sheets from said first conveying means between circumferentially successive arms (24) of said star wheel, said star wheel further being disposed at a first longitudinal end of said second conveying means (31) such that said longitudinal axis of said hub is substantially parallel to said second direction; means for rotating said star wheel about said longitudinal axis of said hub; and reciprocable means (29) for displacing sheets from said star wheel on to said second conveying means (31) in a direction substantially parallel to said longitudinal axis of said hub (23).

Description

[0001] This invention relates to apparatus for re-orientating sheets, e.g. of paper. This is a divisional Application divided out from EP-A-0194008 which relates to the trimming of paper webs and sheets, particularly in the production of paper in sheet or web form, more especially writing paper, with decorative, non-rectilinear edges, e.g. of a deckled nature.

[0002] EP-A-0194008 discloses a first trimming process practised on a web of paper to remove opposed longitudinally running edge portions therefrom. Following this, the web is separated into sheets. It is then desired to re-orientated those sheets with respect to their direction of conveyance to allow trimming of their newly generated edges.

[0003] To this end, the present invention provides a conveyor apparatus comprising: a first conveyor means for conveying sheets in a first direction; a second conveyor means for conveying sheets in a second direction substantially perpendicular to said first direction; and means for receiving sheets conveyed by said first conveying means and for supplying said sheets conveyed by said first conveying means to said second conveying means, said means for receiving and supplying including: a star wheel having an axially elongated hub, having a plurality of arms extending radially from said hub and spaced circumferentially about said hub, said star wheel being mounted at a longitudinal end of said first conveyor means, a longitudinal axis of said hub being disposed substantially transverse to said first direction so as to receive sheets from said first conveying means between circumferentially successive arms of said star wheel, said star wheel further being disposed at a first longitudinal end of said second conveying means such that said longitudinal axis of said hub is substantially parallel to said second direction; means for rotating said star wheel about said longitudinal axis of said hub; and reciprocable means for displacing sheets from said star wheel on to said second conveying means in a direction substantially parallel to said longitudinal axis of said hub.

[0004] Preferably, said star wheel has a plurality of circumferentially spaced groups of radially extending arms, the arms in each said group being spaced axially along said hub and substantially mutually parallel to one another, said first conveying means including a plurality of parallel conveyor units interdigitating with the arms of each said group as said star wheel rotates about said axis.

[0005] Preferably, said first and second conveying means convey sheets substantially horizontally.

[0006] Preferably, said first and second conveyor means convey sheets in substantially co-incident horizontal planes.

[0007] The change in travel direction may thus be accomplished by depositing each sheet between radial arms of a star wheel comprising a hub and a plurality of radial arms extending therefrom, the arms being suitably provided by coplanar sets of rods, each sheet being deposited in a radial direction with respect to said hub, and removing each sheet from said star wheel in a direction parallel to the axis of said hub.

[0008] The sheets may be received from a first trimming station by apparatus according to the invention and then may be conveyed in their new travel orientation to a second trimming station for the trimming of one or both edges.

[0009] The invention will be illustrated by the following description of a preferred embodiment with reference to the accompanying drawings in which:-

Figure 1a is a schematic side elvation of an upstream part of apparatus according to the invention; and

Figure 1b is a side elevation of the downstream part of the apparatus of Figure 1a.

[0010] In the first place, a general description of the function of the machine will be given. A paper web 2 which is slightly wider than the desired width of the finished sheet is reeled off a magazine roll 1 and is passed over a deflection roller 3. Since the paper web 2, which is stored on the roll acquires a tendency to curl up, the paper web 2 is drawn through a so-called decurling device 25 consisting of two pairs of rollers placed at a distance from each other and of bars or guide surfaces arranged between them which are vertically adjustable and over which the web is led. Owing to the web 2 being drawn over the said bars of guide surfaces, which are set in such a manner that the web obtains a tendency to curve in a direction opposite to its curling, the web will be substantially plane when it has passed through the decurling unit. The web 2 is passed subsequently over a deflection roller 4 and up on to a matrix cylinder 5 whose function is to grind a water mark like pattern on to the web at intervals or to produce other features as described below. The web 2 is passed over the matrix cylinder 5 and down over a further deflection roller 7. Adjoining the matrix cylinder 5, a rapidly rotating grinding cylinder 6 is arranged with the help of which selected parts of the web 2 are ground off, so that weakening lines, folding lines, perforations or figured marks of the type of water marks are formed, which is made possible by the grinding being carried out at varying depth on portions adjoining each other.

[0011] The grinding is not a precondition for the function of the machine and the grinding unit may be disengaged, e.g. by removing and disconnecting the grinding cylinder 6.

[0012] The web 2 subsequently is passed over the deflection roller 8 whereupon it is advanced to the edge tearing unit which substantially consists of an endless belt 14 which runs over the deflection rollers 11, 12 and 13 and over a tearing pulley 10 which is adjustable in its position. The tearing is carried out so that the web 2 is conveyed over a supporting member 26, the edge zones of the web 2 intended for tearing off being covered by the tearing belts 14 along the area 27 between the deflection roller 12 and the tearing pulley 10. The central zone of the web is held down by a hold-down member 46. Outwardly of the central zone, rollers 12 act as hold down members and the belts 14 pass beneath them. The said edge zones which are held fast between the belts 14 and the tearing pulleys 10 will be pulled along with the belts as these move down towards the deflection rollers 11, the edge zones being torn off as strips which are collected in, and sucked away through, a tubing 55. The edge zones of the web 2, as a result of the tearing, have obtained an uneven, decorative edge which, however, does not have a defined, matched, transverse dimension, since certain edge portions may jut out in front of the others. Since it is important that there should be an exact transverse dimension on the finished sheets, the uneven edge is trimmed with the help of cutting rollers 15 which cut away the tops of the uneven edge so that an exact transverse dimension on the web 2 is achieved. As the longitudinal edges of the web are now finish-torn and trimmed, the web will be divided up into sheets, the transverse zones of which also have to be torn so as to obtain a decorative edge structure, and subsequently be trimmed, so that the sheet obtains a specified longitudinal dimension.

[0013] In the case where the sheet has been provided with water marks, which may be so-called true water marks, produced already in conjunction with the paper manufacture or marks provided in the web 2 by means of grinding, these water marks or other marks must be located in such a manner on the paper sheets that they reappear again at a certain specified place on each sheet. In order to achieve this it is necessary that the division of the web 2 into sheets should take place bearing in mind the placing of the said marks, that is to say the division into sheets has to take place in register with the placing of the marks. For this purpose, a reading device is arranged, preferably a photocell device 16, which, e.g. by transillumination of, or reflective radiation against, the web, detects and reads the said mark in its position, and as a function of the reading result delivers a pulse to a controller by means of which a pair of cylinders 17 provided with compression tools 18 is made to engage with the web in order to carry out a linear pressing down of the paper material across the web 2 so as to crush the paper fibres and weaken the web along the said compression zone across the longitudinal direction of the web. This compression arrangement 17 may be substituted in principal by a perforation device and in both cases it is the intention to weaken the strength of the paper web 2 along the processing zone. By controlling the working cycle of the processing cylinders 17 by the photocell device 16, the paper web, which normally passes freely between the cylinders 17, can be compresssed in the manner indicated above in a linear zone across the web 2, the said linear compression zone always having a matched position in relation to the marks read by the photocell device 16.

[0014] The web 2, thus provided with transverse weakening lines, is introduced between two cylinders 19, the upper of which cylinders is rubber-covered whereas the other one is a steel cylinder. The cylinders 19 rest against each other under a certain adjustable spring force so that the paper web 2 can be introduced and pass between the cylinders 19 as they rotate whilst being held fast at the same time between the cylinders so that any actual sliding betweeen the paper web 2 and the cylinders 19 cannot occur. The cylinders 19 are driven at a constant speed which corresponds to the speed of the web 2 in all the foregoing operations. After it has passed the pair of cylinders 19, the paper web 2 is introduced between a second pair of cylinders 21 which in principle is the same as the pair of cylinders 19, that is to say the driven cylinder has a rubber covering 20 whereas the other cylinder is a steel cylinder. However, the cylinders in the pair of cylinders 21 are not at a constant driving speed and their mean speed is a little higher than the speed of the pair of cylinders 19 with the help of a planetary gear train which is driven by a cam, coupled to the driving device for the compression cylinders 17. With the help of the planetary gear train which is controlled by the said cam the driving speed of the cylinders 21 can be increased or diminished owing to the planetary gear train providing a periodical additional contribution to, or a reduction of, the driving speed of the cylinders 21. In principle the arrangement functions in such a manner that the web 2 advanced between the cylinders 19 is fed in between the pair of cylinders 21. The pair of cylinders 21, however, moves in this part of the working cycle at a lower speed than the pair of cylinders 19, which means that the pair of cylinders 19 advances more of the web 2 than is taken up between the pair of cylinders 21.

[0015] This means that the said "slack" on the web 2 is not only compensated, but that the web 2 is pulled away so that rupture takes place in the previously mentioned weakened zones across the web 2, which were produced with the help of the compression tool 18 which is located on the cylinders 17. The front part of the web 2 pulled away is advanced at a higher speed that the remainder of the web which is controlled by the pair of cylinders 19 and the separated part of the web is delivered on to a conveyor 22 (constituting the first conveyor means of the invention) consisting of a number of parallel endless belts, this conveyor being driven synchronously with a take-up star wheel 56.

[0016] When the separated sheets have been delivered on to the conveyor 22 they will be collected by rodlike arms 24 which are adapted to move in between the belts of the conveyor 22. The said rodlike arms 24 are arranged in several sections parallel with one another on a joint stepwise indexed centre 23, the rate of indexing of which is adapted to the rate of feed of the sheets. The separated sheets which are delivered onto the conveyor 22 are thus captured and lifted off the conveyor by the said rodlike arms 24.

[0017] In Fig. 1b is shown a continuation of the machine which is set at an angle of 90° to the machine shown in Fig. 1a. In the part of the machine shown in Fig. 1b, the tearing of the short sides of the separated sheets is performed so that a decorative edge zone is formed whereupon the said edge zone is trimmed to the exact longitudinal dimension of the individual sheets.

[0018] As mentioned earlier, the separated sheets are transported with the help of the stepwise rotating star wheel arrangement 56 in such a manner that the sheets are turned by 180°. When the sheets have been brought into position I in Fig. 1a which is shown in the left part of Fig. 1b, the sheets are displaced to the right off the star wheel 56 by means of a reciprocating finger 29 which is controlled by a pneumatic or hydraulic cylinder 28 so that the sheets 43 can be inserted between two endless travelling bands 30 and 31, these bands capturing and transporting the sheets 43 between them.

[0019] The upper band 30 runs between deflection rollers 32 and the lower band 31 runs between deflection rollers 33 and slides over a fixed base 41. The bands 30 and 31 can be pressed towards each other with the help of rollers 34 which act against the inside of the band 30 in the region where the two bands lie adjoining each other. The width of the bands 30 and 31 is less than the length of the sheet 43 so that the edge zones of the sheets 43 project beyond the bands 30 and 31. On introduction between the bands 30 and 31 the sheets 43 are adjusted carefully in lateral direction so that the position of the projecting edge zones is accurately controlled. The individual sheets 43 are transported between the bands 31 and 30 with the said edge zones of the sheets being guided in over a belt 38 of an edge tearing device provided on each side of the apparatus. The edge zones of the sheets 43 will be pressed against the belts 38, one belt whereof is arranged on either side of the machine. Tearing pulleys 36 overlie each belt 38 and the edge portions of the sheets. When the edge zones of the sheets 43 approach the tearing pulleys 36 the edge zones will be taken up between the tearing pulleys 36 and the tearing belts 38 and when the tearing belts 38 are led upwards the edge zone will be torn off, whereupon the waste strip is removed by being sucked up through a tube 35. The tearing belts 38 are endless belts which are passed over deflection rollers 37. After the edge tearing operation the sheets 43, now having torn edges, are conveyed past cutting discs 42 set at an accurate distance from each other, by means of which the tops of the torn edges which project beyond the nominal longitudinal dimension of the sheets 43 are cut off. The sheets 43 are conveyed further between the belts 30 and 31 and are deposited in a collecting device 40.

[0020] Whilst the invention has been described with reference to particular preferred characteristics of the illustrated embodiment, it will be appreciated that many modifications and variations thereof are possible within the scope of the invention.

Claims

1. A conveyor apparatus comprising: a first conveyor means (22) for conveying sheets in a first direction; a second conveyor means (31) for conveying sheets in a second direction substantially perpendicular to said first direction; and means (23, 24) for receiving sheets conveyed by said first conveying means (22) and for supplying said sheets conveyed by said first conveying means (22) to said second conveying means (31), said means for receiving and supplying including: a star wheel having an axially elongated hub (23), having a plurality of arms (24) extending radially from said hub and spaced circumferentially about said hub, said star wheel being mounted at a longitudinal end of said first conveyor means (22), a longitudinal axis of said hub being disposed substantially transverse to said first direction so as to receive sheets from said first conveying means between circumferentially successive arms (24) of said star wheel, said star wheel further being disposed at a first longitudinal end of said second conveying means (31) such that said longitudinal axis of said hub is substantially parallel to said second direction; means for rotating said star wheel about said longitudinal axis of said hub; and reciprocable means (29) for displacing sheets from said star wheel on to said second conveying means (31) in a direction substantially parallel to said longitudinal axis of said hub (23).

2. An apparatus as claimed in Claim 1 wherein said star wheel has a plurality of circumferentially spaced groups of radially extending arms (24), the arms in each said group being spaced axially along said hub (23) and substantially mutually parallel to one another, said first conveying means (22) including a plurality of parallel conveyor units interdigitating with the arms of each said group as said star wheel rotates about said axis.

3. An apparatus as claimed in Claim 1 or Claim 2, wherein said first and second conveying means (22, 31) convey sheets substantially horizontally.

4. An apparatus as claimed in Claim 3, wherein said first and second conveying means convey (22, 31) sheets in substantially conincident horizontal planes.

Drawing