GB2403446A

GB2403446A - Panel cutting apparatus

Info

Publication number: GB2403446A
Application number: GB0314094A
Authority: GB
Inventors: Wayne Lawson
Original assignee: MOLAN
Current assignee: MOLAN
Priority date: 2003-06-18
Filing date: 2003-06-18
Publication date: 2005-01-05
Also published as: GB0314094D0

Abstract

Apparatus for cutting a plurality of panels from a workpiece of sheet material comprises a bed 1 for supporting the workpiece, the bed having a substantially flat support surface, carriage means 2, and cutting means 24 for cutting the workpiece. The cutting means 24 is mounted on the carriage means 2, which is operable to move the cutting means relative to the support surface so as to produce cuts in a workpiece supported on the surface to define edges of panels. The apparatus further comprises pushing means 31, for engaging an edge of a workpiece supported on the surface, and drive means 4 operable to drive the pushing means relative to the bed, in a direction substantially parallel to the support surface, whereby panels may be cut in a workpiece and the workpiece may then be pushed at least partially off the bed for further processing.

Description

PANEL CUTTING APPARATUS

Field of the Invention

The present invention relates to apparatus for cutting a plurality of panels from a workplace of sheet material, and in particular, although not exlusively, to apparatus for cutting panels from sheets of polycarbonate multi-wall material, for use in conservatory roofs.

Background to the Invention

Multi-wall polycarbonate sheet is a material commonly used for conservatory roof panels. It is typically supplied in large rectangular sheets, having widths and lengths of a few metres, and thicknesses in the region of 1 to a few centimetres. The roof panel or panels for a particular conservatory design are cut from such stock sheets. Various cutting methods may be used, and one known technique is to use an angled blade mounted on a moveable carriage. The stock sheet is first placed on a cutting table, which is also known as a bed. The bed has a perforated surface, and a layer of porous material, such as felt, lies on top of this perforated surface. The stock sheet, (workpiece) sits on top of the felt layer. Thus, the upper surface of the felt is the surface actually supporting and in contact with the workpiece. When the stock sheet is positioned correctly, suction is provided via the perforations and porous layer to hold the workpiece in place. Then, a carriage is con- trolled to move relative to the bed, to push the cutting blade into the sheet material and make a plurality of line cuts in the stock sheet. Those line cuts define the edges of the panels. The carriage typically comprises means for moving the blade up and down relative to the bed, and takes the form of a gantry, moveable along the bed, and a shuttle assem- bly mounted on the gantry for moving the blade backwards and forwards across the bed.

The movement of the blade is typically controlled by a computer, which is supplied with a respective date file for each stock sheet. This date file determines the shapes, sizes, and positions of the panels to be cut from the particular stock sheet.

Specification MOLANU K P11 45.GBA 2003-06-1 6.doc In the past, after the cutting process had been completed, the workpiece was pulled manually onto another bed or table where the cut panels would be separated from the redundant, waste material in the stock sheet. With typical panel lengths in the region of a few metres, this transfer process was a two- person job, with one person pulling at each end of one long side of the stock sheet. Two people were needed as, with the sepa- rating table positioned up against the side of the cutting table, the centre point of one long edge could not be reached, and if a single person were to pull the sheet from one end only, this would simply result in rotation of the sheet about a centre point, rather than translation on to the separating table.

Embodiments of the present invention therefore aim to provide improved panel cutting apparatus.

Summary of the Invention

According to the present invention, there is provided apparatus for cutting a plu- rality of panels from a workpiece of sheet material, the apparatus being as defined by claim 1.

The drive means may be operated by a single operator to transfer a cut sheet onto an adjacent separating table.

Preferably, the pushing means extends along a length of the bed so that it can en- gage an edge of the workpiece at a plurality of positions along that edge. Thus, rather than driving the workpiece at a single position, the pushing means can engage it in such a way so as to translate the workpiece towards a separting table without imparting rotation to the workpiece.

Preferably, the pushing means comprises a plurality of pushing members spaced apart along a length of the bed (and hence along the support surface) to engage the workpiece edge at different respective positions along the edge's length.

Specification NOLAN U K P 114 5.G BA 2003-06-1 6. doc Preferably, the drive means is arranged to drive the pushing members in syn- chrony, i.e. to drive them in the same direction at the same time.

Preferably the pushing means comprises a beam which extends a long a length of the support surface, and hence along the bed. More preferably, the beam extends beyond both ends of the support surface. Thus, the beam can provide a pushing edge which can engage with a workpiece edge along the entire length of that edge, and so maintain the orientation of the workplace as it is translated over the bed surface.

Typically, the bed and support surface are generally rectangular, and the beam may extend along a direction substantially parallel to an edge of the support surface. The drive means may be arranged to drive the beam in a direction perpendicular to the length of the beam, across at least a portion of the width of the support surface.

Preferably the beam is supported such that it is spaced from and is parallel to the support surface. It may be spaced above the surface. Advantageously, the apparatus may comprise at least one roller, attached to the beam, and arranged to roll over the support surface and support the beam at an intermediate position, i.e. a position somewhere be tween the beam's ends. For long beams, a plurality of rollers may be used, for example 2, 3 or more.

Preferably, the apparatus comprises a plurality of spacer members, spaced apart along an edge of the beam. These spacer members should be arranged on the "leading" edge of the beam, and extend from that leading edge in a direction generally parallel to the support surface.

Preferably, the spacer members may comprise nylon fingers. Other forms of spacer members may be used, such as blocks of resilient material.

In certain preferred embodiments, the beam is steel, and the spacer members provide the advantage that they separate the workplace from the steel and so prevent

Specification MOLANUKPl 145.GBA 2003-06-1 6.doc r

damage of the cutting means (typically a blade) when cuts are made close to the edges of the workplace and when cuts slightly over-shoot the edges of the workpiece. The spacer members are preferably removably mounted on the beam, i.e. they are preferably repla- cable items.

Advantageously, the carriage means comprises a gantry which extends across a width of the bed and is controllable to move to and fro along a length of the bed to carry the cutting means over a length of the support surface. The beam in certain preferred embodiments is arranged under the gantry.

Preferably, the pushing means comprises an extension, which is attached to the beam and extends from a leading edge of the beam in a direction substantially parallel to the support surface and substantially perpendicular to the length of the beam. The beam and extension may thus define a corner in which to locate a corresponding corner of a workpiece. As with the beam itself, the extension may carry at least one spacer member, for example for engaging an end edge of the workpiece.

Preferably, the beam has an "L" shaped cross-section. This "L" shaped cross- section preferably comprises an elongate horizontal portion, and a shorter vertical sec tion, extending upwards from a trailing edge of the horizontal portion. This cross-section has been found to provide good rigidity along the length of the beam, whilst retaining a relatively low profile such that the beam can be accommodated under the gantry of the carriage means.

Preferably the drive means comprises a actuator arranged to drive one end of the beam. Thus the actuator may be connected to one end, or may be connected close to one end of the beam. Preferably the actuator is a linear actuator, and may be pneumatic.

Preferably the drive means comprises a linking drive mechanism, which links one end of the beam to the other, and is arranged such that movement of the end driven by Specification MOLANU K P11 45.GBA 2003-06-1 6.doc r 5 the actuator is communicated to the other end. Thus, the combination of actuator and linking drive mechanism may move the beam across the cutting table, maintaining its alignment with respect to one edge of the table.

The linking drive mechanism may conveniently employ chains, sprockets, and an axle, although other linking mechanisms may be used.

Preferably the drive means is operable to position the pushing means to define a reference position relative to the support surface for at least one edge of a workpiece.

Thus, the pushing means may perform two functions. It can be used as a location device for locating the workpiece prior to the cutting operations. It can then be used to urge the cut workpiece off the cutting bed, onto a separation table for example.

Preferably, the drive means is further operable to withdraw the pushing means away from the reference position after locating a workpiece on the bed. Thus, the push ing means can be used to locate the workpiece. Suction may then be used to hold the workpiece in that position, and the pushing means is withdrawn such that it is not dam aged by the cutting means when cuts are made close to the edge of the workpiece or in deed when the cuts overshoot those edges. Furthermore, by withdrawing the pushing means during the cutting operation, damage to the cutting means itself, e.g. cutting blade, can also be avoided.

Brief Description of the Drawings

Embodiments of the present invention will now be described with reference to the accompanying drawings, of which; Fig 1 is a schematic representation of cutting apparatus embodying the present in vention;

Specification MOLANUKP1145.GBA2003-06-16.doc r - 6

Fig 2 is a schematic cross section of part of an embodiment; Fig 3 is a schematic perspective view of part of the pushing means of a further embodiment; and Fig 4 is a schematic end view of some components of yet another enbodiment.

Detailed Description of the Preferred Embodiments

Referring now to Fig 1, a first embodiment of the invention comprises a support bed 1 (cutting table). Cutting means in the form of a blade 24 is mounted on a carriage 2.

The carriage comprises a gantry 21 which is moveable along a length of the bed 1 in the direction shown by arrows 26. Mounted on the gantry 21 is a shuttle assembly 22 which is operable to move to and fro along the gantry 21, i.e. across the width of the bed 1. The shuttle assembly 22 itself carries the blade support mechanism 23. This mechanism is op erable to move the blade up and down relative to the bed 1 so that it can be inserted in to a workpiece to make cuts. The blade support 23 is also operable to adjust the orientation of the blade edge (it can rotate the blade about a vertical axis, as indicated by arrow 25).

Control means (not shown in the figure) has been used to move the blade 24 relative to the bed 1 to produce a plurality of cuts in a workpiece 9. Those cuts define a plurality of panels 93 in the workplace 9. The apparatus further comprises pushing means 3 which includes a beam portion 31 which extends along the bed 1. In this embodiment the beam 31 extends beyond both, opposite ends of the cutting table 1. The beam 31 is supported parallel to and above the support surface of the table 1. Cylindrical rollers 34 are located in respective windows 35 in the beam 31, and rotate about shafts 36 which are con nected to the beam. These rollers rest on the surface of the cutting table which supports the workpiece 9 and support the beam 31 at intermediate positions and so maintain its generally parallel relationship with the bed 1. Resilient spacers 33 are connected to a lead ing edge of the beam 31, and butt up against a side edge 91 of the workpiece 9. An ex tension portion 32 is connected to the beam 31 and extends in a direction generally paral Specificabon MOLANUKP1 145.GBA2003-06-1 6.doc - 7 lel to the support bed 1 and in a direction generally perpendicular to the length of the beam 31. Attached to the extension portion 32 is another spacer element 33. This spacer element mounted on the extension engages a top edge 92 of the workplace 9. Thus, the beam 31 and extension 32 together define a corner into which the corresponding corner of the workpiece is located.

In this example, the bed 1 is horizontal. One end of the beam 31 is connected to the drive head 41 of a linear actuator 4. In this example, the actuator 4 is a pneumatic actuator, and movement of the drive head 41 is controlled by appropriate control of air supplied to hoses 42. The actuator is operable to move its drive head 41 to and fro (i.e. to the left and to the right in the figure) to push the cut workpiece 9 from the bed 1. The actuator is operated to move the drive head 41 in the direction shown by arrow A. This directly drives one end of the beam 31, to which the drive head 41 is coupled (by means not shown in the figure). This driven end of the beam 31 is also connected via connector plate 43 to a first chain 44. This chain 44 runs around first sprockets 45. Movement of the drive head 41 in the direction shown by arrow A causes the chain to move in the di rection shown by arrow B. which in turn causes rotation of the sprockets 45. One of these sprockets is coupled to a shaft or axle 46, which is rotated in the direction shown by arrow C. The drive shaft 46 extends from one end of the bed 1 to the other, where it drives one of a second pair of sprockets 47. This in turn causes movement of a second chain 48 in the direction shown by arrow D. This second chain motion is communicated via coupling plate 49 to a second end of the beam 31. Thus, the initial movement A of the actuator head 41 causes the beam 31 to move in the direction shown by arrows F. main taining the orientation of the beam 31 substantially parallel to the long edge of the cutting table 1. As the beam 31 is driven across the table, spacers 33 engage and drive the work piece off the bed 1.

Also shown in Fig 1 are adjustable stops 5 which limit movement of the beam in one di rection. The intersection between an edge of the extension portion 32 and the leading edge of the beam 31 defines an origin X. Before the cutting process begins on a work

Specification MOLANUKP1145.GBA2003-06-16.doc - 8

piece, the drive means is controllable to move the beam 31 so that this origin occupies position P1. The workpiece 9 is then located against the spacers 33 and the workpiece is then at the correct position for the start of the cutting process. Suction is then applied to hold the piece in this position during the cutting operation. The drive means is adapted, in this embodiment, then to withdraw the beam 31 such that the intersection X occupies position P2. This is to prevent damage of the pushing means by the cutting means, and vice versa.

Moving on to Fig 2, this shows a schematic cross section of part of a further embodiment.

The cutting table comprises a perforated bed surface covered by a porous layer of felt 12.

The upper surface of the felt 12 thus defines the support surface 10 of the cutting table.

Resting on the support surface 10 is a workpiece 9 in the form of a sheet of multi-wall polycarbonate material. Part of a pusher assembly is shown driving the workpiece 9 along the support surface 10. The pusher assembly comprises a steel beam 31 having a window 35 in which is mounted a nylon roller 34 on a shaft 36. The roller engages the support surface 10 and maintains the beam 31 in parallel relationship with the bed, slightly above and separated from the felt layer 12. The beam 31 is "L" shaped in cross-section, having an elongate horizontal portion 31 and a vertically extending rear wall 310. This shape gives a low profile, suitable for passing under a gantry 21, yet retains a good degree of rigidity along the beam's length. A support pin 311 extends from a leading edge of the beam 31, and on that pin is mounted a nylon finger 330. It is this finger 330 which di- rectly engages the edge of the workpiece 9. If damaged by the cutting means, the nylon finger can easily be replaced.

Moving on to Fig 3, this shows part of the pushing means of yet another embodiment.

Again, the beam 31 is generally "L" shaped, having a vertical rear (trailing) wall. An ex- tension portion 32 extends perpendicularly from the leading edge of the beam 31 and carries a plurality of nylon fingers 330 which are spaced apart in a direction which corre- sponds to the width of the cutting table. A further plurality of nylon fingers 330 extends

Specification MOLANUKP11 45.GBA 2003-06-1 6.doc - 9 -

from the leading edge of the beam 31. The tips of the array of fingers can thus locate and engage the corner edges of a work piece.

Moving now to Fig 4, in this embodiment the pushing means again comprises a generally "L" shaped beam 31, having a vertical rear wall 310. The beam 31 is mounted slightly above and parallel to the upper surface 10 of the support bed. An end of the beam 31 is connected to a rigid bracket 430 by means of bolts 99. This bracket is welded to a plate 43. The bracket and plate are themselves bolted to the drive head 41 of a linear pneu matic actuator 4. This actuator comprises a cover strip 40 which prevents the ingress of contaminants into the cylinder and piston arrangement housed within the actuator 4. The plate 43 is connected via a series of pins to a drive chain 44, which runs around sprockets 45. One of the sprockets is coupled via a drive shaft to a drive chain at the opposite end of the cutting table. In this embodiment, the sprockets rotate about axes which are horizontal.

Specification MOLANUK PA 1 45.GBA 2003-06-1 6.doc - 1 0

Claims

Claims 1. Apparatus for cutting a plurality of panels from a workpiece of

sheet material, the apparatus comprising: a bed for supporting the workpiece, the bed having a substantially flat support sur face; carriage means; and cutting means for cutting the workpiece, the cutting means being mounted on the carriage means and the carriage means being operable to move the cutting means relative to the support surface so as to produce cuts in a workpiece supported on the surface to define edges of panels, the apparatus fur ther comprising: pushing means, for engaging an edge of a workpiece supported on the surface; and drive means operable to drive the pushing means relative to the bed, in a direction substantially parallel to the support surface, whereby panels may be cut in a workpiece and the workpiece may then be pushed at least partially off the bed for further processing.
2. Apparatus in accordance with claim 1, wherein the pushing means extends along a length of the support surface, whereby the pushing means can engage said edge at a plu rality of positions along said edge.
3. Apparatus in accordance with any preceding claim, wherein the pushing means comprises a plurality of pushing members spaced apart along a length of the support sur- face to engage a workpiece edge at different respective positions along the edge's length.
4. Apparatus in accordance with claim 3 wherein the drive means is arranged to drive the pushing members in synchrony.

Specification MOLANUKP11 45.GBA 2003-06-1 6.doc - 1 1
5. Apparatus in accordance with any proceeding claim, wherein the pushing means comprises a beam extending along a length of the support surface.
6. Apparatus in accordance with claim 5 wherein the beam extends beyond ends of the support surface.
7. Apparatus in accordance with claim 5 or claim 6, wherein the support surface is generally rectangular, and the beam extends along a direction substantially parallel to an edge of the support surface.
8. Apparatus in accordance with any one of claims 5 to 7, wherein the drive means is arranged to drive the beam in a direction perpendicular to the length of the beam, across at least a portion of the width of the support surface.
9. Apparatus in accordance with any one of claims 5 to 8, wherein the beam is sup- ported such that it is spaced from and parallel to the support surface.
10. Apparatus in accordance with any one of claims 5 to 9, and comprising at least one roller, attached to the beam, and arranged to roll over the support surface and sup- port the beam at a position between the beam's ends.
11. Apparatus in accordance with any one of claims 5 to 10 and further comprising a plurality of spacer members, spaced apart along a leading edge of the beam.
12. Apparatus in accordance with claim 11 wherein the spacer members comprise nylon fingers.
13. Apparatus in accordance with any one of claims 5 to 12, wherein the carrigae means comprises a gantry, extending across a width of the bed and moveable to and fro

Specification MOLANUKP11 45.GBA 2003-06-1 6.doc - 1 2

along a length of the bed to carry the cutting means over a length of the support surface, the beam being arranged to extend under the gantry.
14. Apparatus in accordance with any one of claims 5 to 13, wherein the pushing means comprises an extension, attached to the beam and extending from a leading edge of the beam in a direction substantially parallel to the support surface and substantially perpendicular to the length of the beam, the beam and extension defining a corner to lo- cate a corner of a workpiece.
15. Apparatus in accordance with claim 14, comprising at least one spacer member attached to the extension, for engaging an edge of a workpiece on the bed.
16. Apparatus in accordance with any one of claims 5 to 15, wherein the beam has an "L" shaped cross section.
17. Apparatus in accordance with any one of claims 5 to 16, wherein the drive means comprises an actuator, arranged to drive one end of the beam.
18. Apparatus in accordance with claim 17 wherein the actuator is a linear actuator.
19. Apparatus in accordance with claim 17 or claim 18, wherein the drive means comprises a linking drive mechanism, linking one end of the beam to the other, and ar- ranged such that movement of said one end of the beam driven by the actuator is com- municated to the other end.
20. Apparatus in accordance with claim 19, wherein the linking drive mechanism com- prises a first chain, connected to the driven end of the beam, a first sprocket rotated by the first chain, axle means communicating rotation of the first sprocket to a second sprocket, and a second chain, connected to the second end of the beam and engaging the second sprocket.

Specification MOLANUKP1 145.GBA2003-06-1 6.doc - 1 3
21. Apparatus in accordance with claim 20 wherein the first and second chains are arranged at opposite ends of the bed, and the axle means extends fron one end of the bed to the other.
22. Apparatus in accordance with any preceding chain wherein the drive means is operable to position the pushing means to define a reference position relative to the support surface for at least one edge of a workpiece.
23. Apparatus in accordance with claim 22, wherein the drive means is further oper- able to withdraw the pushing means away from the reference position after locating a
24. Apparatus substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.

Specification MOLANUKP11 45.GBA 2003-06-1 6.doc