GB2219235A

GB2219235A - Method and apparatus for rounding-off the corners of piles of sheets

Info

Publication number: GB2219235A
Application number: GB8912873A
Authority: GB
Inventors: Siegmar Neubuser
Original assignee: ECH Will GmbH and Co
Current assignee: ECH Will GmbH and Co
Priority date: 1988-06-04
Filing date: 1989-06-05
Publication date: 1989-12-06
Anticipated expiration: 2009-06-05
Also published as: FR2632247B1; FR2632247A1; IT8920660A0; JPH0224098A; GB8912873D0; GB2219235B; IT1230213B; DE3819142A1

Description

41 2219235 METHOD OF AND APPARATUS FOR ROUNDING-OFF CORNERS The invention

relates to a method of and apparatus for rounding-off the corners of piles of sheets, for example of pads.

It is already known to round-of f piled-up sheet material at the corners. Thus, DE-AS 1 268 588 discloses a device for rounding the corners of sheet material, four cutters with a correspondingly circular cutter edge acting in the manner of a guillotine on the four corners of an aligned pile of sheets. An adjustment of the cutters to different sheet formats. is not provided in this case. Even if such a possibility of adjustment were available, then with this principle of the device, according to which all four corners of a pile are rounded at the same time by the four cutters, the positions of all four cutters with respect to each other would have to be varied. This necessitates high expenditure on adjustment work, which would be multiplied if such devices were provided on machines operating with multiple uses.

It is an object of the invention to obviate or mitigate the aforesaid disadvantage.

A method is therefore proposed according to the invention, which consists in that the piles of sheets are moved in succession along a conveying path and two adjacent piles of sheets in the conveying direction are respectively fixed at a definite spacing from each other in the operating region of punching tools and that respectively the rear corners of the leading pile of sheets and the front corners of the trailing pile of sheets are rounded off simultaneously.

A further feature of the method according to the invention consists in that after rounding of its front corners, the trailing pile of sheets is conveyed further by a distance which is equal to its. length plus the spacing of the punching tools, seen respectively in the conveying direction.

Furthermore it is provided that the trailing pile of sheets is held in fixed alignment as it is conveyed further, after rounding of its front corners.

For this purpose, an apparatus is characterised according to the invention by the fact that conveying means are provided for conveying the piles of sheets in succession along a conveying path, that means are provided for forming a definite spacing between a leading pile of sheets and a trailing pile of sheets respectively and for fixing these piles of sheets in this spacing in the operative region of the punching tools and that the punching tools are arranged at such a spacing from each other that simultaneously the rear corners of the leading pile of sheets and the front corners of the trailing pile of sheets respectively are punched. One feature of the invention also consists in that several punching tools respectively are disposed in tool units, so that these punching tools carry out a simultaneous and equal punching stroke. It is also provided according to the invention that two punching tools are respectively disposed in a tool unit, one acting on a rear corner 1 3 of the leading pile of sheets and one acting on a front corner of the trailing pile of sheets. Two such tool units respectively are required in the case of a single-station supply of the piles of sheets or also for the outer corners of the outer pile of sheets in the case of a multiple-station method of operation. Furthermore, in an advantageous embodiment it is provided according to the invention that with a multiple-station formation of the piles of sheets, four punching tools are respectively disposed in a tool unit, each one acting on one of the facing corners of two adjacent leading and two adjacent trailing piles of sheets. The invention also consists in that the conveying means comprise a supply conveyor for the new pile of sheets and a discharge conveyor for the finished pile of sheets. Furthermore, a stop for the trailing pile of sheets respectively is provided, which stop may be introduced into the conveying path of the piles of sheets. In this case, the stop is constructed to tilt in a controlled manner.

According to the invention, it is also proposed that disposed on the discharge side are tongs able to travel along the conveying path, for moving up a pile of sheets respectively to the said spacing with respect to the trailing pile of sheets. The said stop member and the said tongs thus together form the means for achieving the said definite spacing between a leading and a trailing pile of sheets.

A further feature according to the invention consists in that disposed on the tongs is an entrainment member able to be introduced in a controlled manner into the conveying path, for pushing out the finished, punched pile of sheets during moving up of the follow ing, half-finished pile of sheets.

According to the invention it is also provided that respectively associated with the tool units - 4 is an arrangement of counter-blades corresponding to the arrangement of their individual punching tools. Furthermore it is provided that the tool units contain holding and attachment means for the individual punching tools. Furthermore, it is proposed according to the invention that the tool units are movable relative to the counter-blades. In this case, according to a further feature of the invention, the tool units are securely connected to vertical guide rods, which are guided in guides of lower parts receiving the corresponding Counter-blades. In order to facilitate an adjustment of the apparatus to different formats of piles of sheets, it is provided according to the invention that for adjustment to another format width, the tool units with their punching tools as well as the lower parts with their counter-blades are able to move and to be locked at right angles to the conveying direction of the piles of sheets. For this purpose it is also proposed that for adjustment to another format length means are provided for varying the stroke of the tongs when moving-up the piles of sheets. A further feature of the invention consists in that drive means for the tool units are provided for carrying out a vertical punching movement.

As regards the said holding and attachment means for the punching tools, it is also provided according to the invention that each tool unit comprises a tool holder, which is provided with holding magnets for the punching tools. In addition, according to the invention, additional clamping means are provided for attaching the punching tools to the tool holder.

With a substantially reduced amount of adjustment work, the method according to the invention and the apparatus according to the invention facilitate a flexible manufacture of piles of sheets or pads with 1 tt rounded corners, that is to say the apparatus can be adjusted quickly and simply to the different sheet formats.

The invention will be described in detail hereafter with reference to one embodiment. In the drawings:

Figure 1 is a view of the apparatus according to the invention in simplified illustration, Figure 2 is a view of a tool unit and the stationary counter-blade co- operating therewith, partly in section, Figure 3 is the view X according to Figure 2, Figure 4 is the section IV-IV according to Figure 2, Figure 5 is the section V-V according to Figure 2 and Figure 6 is a diagrammatic illustration of the arrangement of several tool units with a multiple-station method of operation.

According to Figure 1, piles of sheets 1 are moved along a conveying path 2 in the direction of an arrow 3. In this case they pass a punching device 4, in which their corners are rounded-off, i.e. punched in a rounded manner. Conveying means are provided in the form of a rotating supply conveyor 6 for supplying new piles of sheets 1 to the punching device 4 and in the form of a rotating discharge conveyor 7 for discharging the finished piles of sheets 1 which have been rounded off at their corners. The supply conveyor 6 and the discharge conveyor 7 are constructed as belts revolving around rollers 6a respectively 7a to 7e, one of the said rollers in each case being driven. A stop able to be swung into the conveying path 2, which is attached to a rocking lever 8a able to tilt in -accordance with the double arrow 9, serves for the exact positioning of the respectively supplied pile of sheets 1 in the punching device 4. Furthermore tongs 11 are provided for moving up a pile of sheets 1 into a predetermined position within the punching device 4, so that a definite spacing a is adjusted between a leading pile of sheets la moved up by the tongs 11 and a trailing pile of sheets lb held back by the stop 8. This spacing a corresponds to the spacing of the punching tools 12 disposed in the punching device 4 to be described in detail at another point, so that at the time of a punching operation, the rear corners of the leading pile of sheets la and the front corners of the trailing pile of sheets lb respectively are rounded off simultaneously. The tongs 11 are able to travel at the discharge side along the conveling path 2, for which purpose they comprise a carriage 10 arranged to slide on a horizontal longitudinal guide 13. The tongs 11 comprise a lower jaw Ila and an upper jaw llb, which are each disposed on a cross-bar 15a and 15b extending at rig ht angles to the conveying direction. The lower cross-bar 15a with the lower jaw lla is securely connected- to the carriage 10. The upper jaw llb together with the upper cross-bar 15b is movable vertically relative to the lower jaw Ila. Due to this relative movement of the upper jaw llb with respect to the lower jaw lla, the opening and closing of the tongs 11 is brought about, for which purpose a rocking lever 14 arranged to tilt on the carriage 10 and a coupling 16 between the rocking lever 14 and the upper jaw llb or its upper cross-bar 15b are provided. The upper jaw llb comprises an entrainment member 17, which can be swung in a controlled manner into the conveying path 2, in order, when moving on a pile of sheets la, to push an already finished pile of sheets 1c, i.e. which has already 1 - 7 been rounded-off at all four corners, in the conveying direction of the discharge conveyor 7 and to bring it to the discharge speed. For introducing and removing the entrainment member 17 into and from the conveying path 2, a lever 19 is therefore located on the upper jaw llb of the tongs 11, which lever is able to tilt about a pivot 21 and is connected to the entrainment member 17, the lever being actuated by way of a controlled actuating member 18. For the said longitudinal movement of the tongs 11 in the direction of a double arrow 22, a toothed belt 26 extending over gears 23, 24 is provided, whereof the upper side 26a. is connected by connecting means 27 to the lower jaw lla of the tongs 11. The longitudinal movement of the tongs 11, i.e. their stroke defined by the format length of the pile of sheets 1 and the said spacing a is introduced into the lower side 26b of the toothed belt 26. For this purpose, the lower side 26b is connected by connecting means 28 to a carriage 29 adjusted to this stroke, which is movable on a guide 32 in the direction of a double arrow 31. This carriage 29 is connected by way of a two-armed lever 34, able to tilt about a pivot point 33, to a part 36 driven with a constant stroke by a control cam (not shown), which part 36 is guided on a guide 37. Due to a displacement of the lever pivot point 33 in the direction of a double arrow 38 along a path 39, it is possible to vary the stroke of the carriage 29 and thus the stroke of the tongs, which 'is necessary in the case of changes to the format length, whilst maintaining the said, definite spacing a between the leading and the trailing piles of sheets la and lb. The said path 39 may be for example a connecting link guide, in which a sliding block comprising the lever pivot point 33 is able to move. However, the path 39 may also be an adjusting spindle, on which an adjusting nut part 35 guided on guides 30a, 30be 8 provided with the lever pivot point 33, is able to move in the direction of the double arrow 38. The punching device 4 comprises a vertically movable upper part 4a, whic h receives a tool unit 4 1 formed from several punching tools 12 and a fixed lower part 4b. Drive means, for example a tie-rod 43 acted upon by way of a drive (not shown) by way of a lever 42, which tie-rod is- guided in a stationary guide 44, moves the upper part 4a with the tool unit 41 in the direction of the lower part 4b, the corners, i.e. the rear corners of the leading pile of sheets la and the front corners of the trailing pile of sheets lb, located in the line of action of the punching tools 12, being rounded-off.

Figures 2 to 5 now show the punching device 4 with its tool unit 41 located in the upper part 4a and its lower part 4b more clearly, the said drive means 42, 43 being omitted in this case. In this case, the tool unit 41 shown here is a unit for service in the case of a multi-station method of operation, piles of sheets 1 being conveyed in several rows one beside the other, as is apparent from Figure 6. According to Figures 2 to 4, the movable upper part 4a comprises a holding plate 46, to which the tool unit 41 is fastened by means of a screw connection 47. In this case, according to Figure 4, the tool unit 41 comprises a tool holder 48, which receives the individual punching tools 12, in this case four members. The tool holder 48 is provided with recesses 49, in which the punching tools 12 are inserted. Let into the bottom of the recesses 49 are holding magnets 51 for holding the punching tools 12. Furthermore, two clamping. members 52 are provided for the additional clamping respectively of two punching tools 12 to the tool holder 48. For this purpose, the clamping members 52 comprise clamping screws 53. The holding plate 46 with the 1 tool unit 41 attached thereto is connected by way of angle sections 54a, 54b to cross-bars 56a, 56b extending at right angles to the conveying direction (arrow 3 in Figure 1). Depending on how many stations are operated, a corresponding plurality of punching devices 4 with tool units 41 is disposed on the said cross-bars 56a, 56b and indeed so that by releasing or tightening screw connections 57a, 57b, they can be moved along the cross-bars 56a, 56b or locked. Thus a corresponding adjustment to different format widths of the piles of sheets 1 is possible. The upper part 4a also comprises guide rods 58a, 58b, by which the movable upper part 4a is guided in the stationary lower part 4b when carrying out its vertical movement (punching stroke). For this purpose, corresponding vertical ball-bearings 59a, 59b are provided in the lower part 4b. The guide rods 58a, 58b are sealed by dirt-repelling rings 61a, 61b at the inlet to the lower part 4b, so that.the ball-bearings 59a, 59b are protected from contamination, which occurs in the form of paper fibre particles, when punching paper. Also provided in the lower part 4b are counterblades 62 for the punching tools 2, in an arrangement which corresponds to the arrangement of the punching tools 12 (Figures 1 and 5). In the case of the said adjustment to another format width, in the same way as the upper part 4a, the lower part 4b is also moved in guides 63a, 63b at right angles to the conveying direction (arrow 3 in Figure 1). For this purpose.

corresponding screw connections 64a, 64b (Figure 5) are released and tightened again after moving the lower part 4b, so that the lower part 4b is fixed in its definite position. The waste material produced by punching may fall through an inner, central hollow area 66 of the lower part 4b into a collecting chamber 67 located therebelow.

-10 Figure 6 shows diagrammatically in plan view the supply of piles of sheets 1 in several stations and the corresponding arrangement of the punching devices 4. In the five-station method of operation shown here, four punching devices 4 of the type shown in Figures 2 to 5 with tool units 41 each consisting of four punching tools 12 are provided, by which the adjacent rear corners of two adjacent leading piles of sheets la and the adjacent front corners of two adjacent trailing piles of sheets lb are roundedoff. simultaneously. Two further punching devices 4 each with tool units 41 consisting of only two punching tools 12 are provided for the rounding-off of the outer rear corner of the leading outer pile of sheets la and of the outer front corner of the trailing outer pile of sheets lb.

As already described, the adjustment to another format length takes place by way of the variation of the stroke of the tongs and the adjustment to another format width takes place by way of the displacement of the punching devices 4 in the cross-bars 56a, 56b and in the guides 63a, 63b. In the format width adjustment, the tongs 11 are moved in a corresponding manner on the said cross-bars 15a, 15b. The tool units 41 remain unchanged as such, i.e. their individual punching tools 12 do not need to be moved. Therefore, it is essential that after each format adjustment, the spacing a between the leading and the trailing piles of sheets la and lb and the lateral spacing b between the piles of sheets la, lb is produced exactly, in order that the corners to be rounded lie exactly in the operative region of the punching tools 12 associated therewith.

11 1

Claims

A method of rounding-of f the corners of piles of sheets, for example of pads, characterised in that the piles of sheets are moved in succession along a conveying path and two respective adjacent piles of sheets in the conveying direction are fixed with a definite spacing from each other in the operating region of punching tools and that simultaneously the rear corners of the leading pile of sheets and the front corners of the trailing pile of sheets respectively are rounded off.
2. A method according to claim 1, characterised in that after the rounding-off of its front corners, the trailing pile of sheets is conveyed further by a distance which is equal to its length plus the spacing of the punching tools, seen respectively in the conveying direction.
3. A method according to claim 1 or 2, characterised in that the trailing pile of sheets is kept with a fixed alignment during further conveyance after rounding of its front corners.
4. Apparatus for rounding-off the corners of piles of sheets, for example of pads, by means of cutting tools provided with a curved cutting edge characterised in that the conveying means are provided for conveying the piles of sheets in succession along a conveying path, that means are provided for forming a definite spacing between a leading pile of sheets and a trailing pile of sheets respectively as well as for fixing these piles of sheets at this spacing in the operating region of the punching tools and that the punching tools are arranged with such a spacing from each other that simultaneously the rear corners of the leading pile of sheets and the front corners of the trailing pile of sheets are respectively punched.
5. Apparatus according to claim 4, characterised in that several punching tools are respectively disposed in tool units so that these punching tools carry out a simultaneous and equal punching stroke.
6. Apparatus according to claims 4 and 5, characterised in that two punching tools respectively are disposed in one tool unit, one respectively acting on a rear corner of the leading pile of sheets and one on a f ront corner of the trailing pile of sheets.
7. Apparatus according to claims 4 and 5, characterised in that with multi-station formation of the piles of sheets, f our punching tools are respectively disposed in a tool unit, each one acting on one of the facing corners of two adjacent leading and two adjacent trailing piles of sheets.
8. Apparatus according to claim 4, characterised in that the conveying means comprise a supply conveyor f or the new piles of sheets and a discharge conveyor for the f inished piles of sheets.
9. Apparatus according to claim 4, characterised in that a stop able to be introduced into the conveying path of the piles of sheets is provided for the respective trailing pile of sheets.
10. Apparatus according to claim 9, characterised in that the stop is constructed to tilt in a controlled manner.
11. Apparatus according to one or more of claims 4 to 10, characterised in that disposed at the discharge side are tongs able to move along the conveying path for moving up one pile of sheets respectively to the said spacing f rom the respective trailing pile of sheets.
12. Apparatus according to claim 11, characterised in that disposed on the tongs is an entrainment member able to be introduced in a controlled manner into the conveying path for pushing-out the finished punched pile of sheets during moving-up of the following, half-finished pile of sheets.

1
13. Apparatus according to claim 5, characterised in that associated respectively with the tool units is an arrangement of counter-blades corresponding to the arrangement of their individual punching tools.
14. Apparatus according to claim 5, characterised in that the tool units comprise holding and attachment means for the individual punching tools.
15. Apparatus according to claims 5, 13 and 14, characterised in that the tool units are movable relative to the counter-blades.
16. Apparatus according to claim 15, characterised in that the tool units are securely connected to vertical guide rods, which are guided in guides of lower parts receiving the corresponding counter-blades.
17. Apparatus according to one or more of claims 4 to 16, characterised in that for adjustment to another f ormat width, the tool units with their punching tools as well as the lower parts with their counter-blades can be moved and locked at, right angles to the conveying direction of the piles of sheets.
18. Apparatus according to one or more of claims 4 to 17, characterised in that f or adjustment to another format length, means are provided for varying the stroke of the tongs at the time of moving-up the piles of sheets.
19. Apparatus according to one or more of claims 4 to 18, characterised in that drive means for the tool units are provided for carrying out a vertical punching movement.
20. Apparatus according to claim 14, characterised in that each tool unit comprises a tool holder, which is provided with holding magnets for the punching tools.
21. Apparatus according to claims 14 and 20, characterised in that additional clamping means are provided for attaching the punching tools to the tool holder.
22. A method of rounding-of f the corners of piles of sheets, substantially as herein described with reference to the accompanying drawings.
23. Apparatus for rounding-off the corners of piles of sheets, substantially as herein described with reference to the accompanying drawings.

Published 1989 at The Patent Office. State House, 86,171 Ihgh Holborn, London WClR 4TP. Further copies imaybe obtained from The Patent Office. Wes Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary CrAY, Kent, COIL -1187 -1 k,