GB2383294A

GB2383294A - A sawing machine for contouring foamed plastics

Info

Publication number: GB2383294A
Application number: GB0130811A
Authority: GB
Inventors: Martin Hayes; Jack O'leary; Kevin Foley
Original assignee: VITA CORTEX TECHNOLOGIES Ltd
Current assignee: VITA CORTEX TECHNOLOGIES Ltd
Priority date: 2001-12-21
Filing date: 2001-12-21
Publication date: 2003-06-25
Anticipated expiration: 2021-12-21
Also published as: GB2383294B; GB0130811D0

Abstract

A contouring machine 3 for cutting a foam workpiece 51 into two sheets 55 and 56 having alternating complementary peaks and hollows comprises a pair of opposed meshing profiling rollers 31 and 32, a bandsaw 36 mounted in a transverse plane midway between the rollers 31 and 32, a conveyor 44 for removing the lower of the two sheets 56 and a height adjustable guide plate 40 projecting upwardly and away from the saw 36 to a position above the conveyor 44. The guide plate 40 guides the upper of the two sheets 55 and thereby ensures that the split workpiece is reconstituted (57, Fig. 1) after sawing with the sheets 55 and 56 accurately aligned. The contouring machine 3 also comprises means (41, Fig. 7) for sensing the position of the cutting edge of the saw 36 relative to the rollers 31 and 32 and means for moving the saw 36 towards and away from the rollers 31 and 32 in response to the sensed position. Workpieces are fed from a slab slitting machine (2, Fig. 1).

Description

"AfnalmMphtica matt*ria!fntouring machinea amh) jctrnduciSon The present invention relates to a compressible synthetic foamed plastics material contouring machine assembly.

Examples of such profiling machines have been described, for example, in PCT Patent Specification No. WO 98\05480 (Foamex LP.).'Further, there are many patent specifications for the cutting of such foamed plastics sheets which require that the two profiled sections be mated together to form. after having been split, a reconstituted sheet One well known way of profiling compressible synthetic foamed plastics material is to

compress a sheet of the material between two profiling rollers and then to use the rollers to push the compressed sheet against a cutting or splitting blade. This then is sliced along a mid point in its thickness into two sheets of equal thickness. When the two resulting sheets return to an uncompressed state, the two foam surfaces created by slicing the original slab or sheet expand to define similar surfaces with alternating peaks and depressions which are geomebically complementary to each other. A typical widely used configuration is the so-catled'egg cote convoluted sheer which provides a supporting surface which is dimpled with rounded peaks and depressions in a checker board pattern. The raised portions form peaks and the depressions hollows on the shaped foamed plastics sheet which correspond in mirror relationship to the raised portions and depressions on the rollers surfaces.

Various problems have been encountered with such machines and considerable concentration has been placed by machinery manufacturers on ensuring that the two rollers are driven precisely and accurately relative to each other so that they always mesh correctly as any mismatch in speed between the rollers would cause considerable distortion of the profiled section, if not tearing of the plastic sheets.

However, there are other problems that become apparent with the use of such profiling machines. Essentially, as explained already, the sheet is slit into two profiled

sheets which then usually have to be cut in some way for subsequent use. Thus, the two sheets split from the original sheet have to be reconstituted, as it were, into a further sheet so that that further reconstituted sheet can be easily cut to desired shapes.

This has led to a considerable amount of difficulty in practice and on many of these machines, up to four people have been required to take off the sheets as they are formed and then reconstitute them into sheets. Unfortunately, as with all manual operations, it is not particularly efficiently done and in any case, even when efficiently done, is very time consuming and costly. Further, it leads to unacceptable waste when incorrectly done.

A further problem is that there is a need to ensure that the actual sheet from which the sheets are to be split and profiled is correctly formed and delivered to the profiling rollers in the correct way.

The present invention is directed to overcoming these problemsClwpmbntn nf InMwnHnn According to the invention there is provided a compressible synthetic foamed plastics material contouring machine assembly comprising a rectangular sheet slitting machine feeding a contouring machine, the contouring machine comprising :a support structure ; a pair of opposed meshing profiling rollers for selectively compressing therebetween a rectangular sheet of foamed plastics material a feed-in table for the sheet adjacent the rollers ; a splitter blade comprising an endless bandsaw mounted in a transverse plane midway between the rollers to s ! ice the compressed sheet as it progresses through the rollers whereby on exiting the rollers, there are two

sheets, namely, an upper sheet and a bottom sheet respectively above and below the splitter blade, which sheets expand to form similar surfaces with alternating mutually complementary peaks and hollows ; a sheet take-off conveyor for leading the bottom sheet away from the splitter blade ; a height adjustable guide plate projecting upwardly and away from the splitter

blade to a position above the take-off. conveyor to deposit the upper sheet onto the bottom sheet in mating relationship with their side edges coinciding and the peaks of-one engaging the hollows'of the other to form a reconstituted sheet ;

.. means for sensing the position of the cutting edge. of the bandsaw relative to the profiling rollers ; and means for moving the bandsaw tongitudinatty towards and away from the rollers in response to the relative positions of the bandsaw and the profiling rollers.

By having the guide plate adjustable, it is possible to adjust the guide for various thicknesses of slab and sheet so that the upper sheet win always coincide with the bottom sheet ensuring they will mate accurately together. In practice, it has been found that it is only necessary to adjust the guide plate infrequently and indeed it has been found that for relatively wide ranges of sheet thickness, there is no need to adjust the plate- However, the great advantages are that now the reconstituted slab is correctly reconstituted and the entire assembly can be operated by one person, thus requiring less supervision- Further, the assembly requires less factory space.

In one embodiment of the invention, the assembly further includes- a support framework ; a cutting blade assembly mounted on a height adjustable carriage on the

support framework ; a reciprocable work piece in-feed table for the cutting blade on the support framework ; a sheet take-off conveyor for the cutting blade having a tail portion connected to the carriage for movement therewith and having a head portion for delivery to the feed-in table for the sheet of foamed plastics material.

The great advantage of this is that there is now delivered to the profiling rohem a. homogeneous sheet which can be accurately worked.

With this latter construction of sheet slitting machine, a sheet take-off conveyor is mounted on an upright support frame terminating in rollers for engagement with a pair of spaced-apart parallel ground engaging tracks. This allows the conveyor to accommodate to the raising and lowering of the tail portion which is connected to the carriage.

In one embodiment of the invention, the splitter blade is mounted in a substantial V- shaped cowling having an exit slot adjacent its apex through which the cutting blade projects and in which the means for moving the bandsaw longitudinally comprises double acting pneumatic rams mounting pusher plates for engaging the non-cutting

edge of the splitter blade, some of the rams being mounted within the cowing. This has the great advantage of allowing the rams to be separated from the foamed plastics material, to avoid contamination and further, to avoid the foam plastics material causing the rams to operate incorrectly.

Ideally, the guide plate forms an extension of the cowting. This is a very suitable construction as the guide plate now provides two functions, firstly of protecting the rams and secondly, its main function of ensuring the upper sheet is deposited onto the bottom sheet in a close and accurate mating relationship.

Ideally, a blade sharpener is provided for continuous sharpening of the splitter blade

in use. Continuous sharpening of the splitter blade ensures that there will be no distortion of the foamed plastics contoured sheets manufactured in accordance with

the invention. This is very important if one is to ensure that subsequent cutting of the reconstituted sheets is carried out accurately.

Ideally, ihe sheet take-off conveyor feeds a final take-off conveyor pivotally mounted on the support structure adjacent the sheet take off conveyor and also mounted by

double acting rams. on the structure for height adjustment of its end remote from the sheet take-off conveyor.

Ideally, in this latter embodiment, control means are provided to raise the height of the end of the main take-off conveyor a distance substantially the same as the thickness of the reconstituted sheet. This ensure that each reconstituted sheet is laid coffecfly at the correct height for subsequent use and it avoids all possibility of the sheets forming the reconstituted sheet of disengaging.

11mf "ption of Inntion The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which :- Fig. 1 is a side view of a machine assembly according to the invention, Fig. 2 is a perspective view of the machine assembly, Fig. 3 is an enlarged view of a rectangular sheet slitting part of the machine assembly as illustrated in Fig. 2, Fig-4 is an enlarged view of a contouring machine forming part of the assembly illustrated in Fig. 2 with portion removed, Fig. 5 is a sectional part diagrammatic view of portion of the contouring machine of Fig. 4,

Fig. 6 is an enlarged sectional view of portion of the assembly similar to Fig.

5, and Fig. 7 is a perspective diagrammatic view of a bandsaw forming part of the contouring machine of Fig. 4.

Referring to the drawings, there is illustrated a compressible synthetic foamed plastics material contouring machine assembly, indicated general by the reference numeral 1 and comprising effectively two machines connected together, name ! y a rectangular slab slitting machine, indicated generally by the reference numeral 2 and a contouring machine, -indicated generally by the reference numeral 3.

Referring now specifically to Fig. 3, the stab slitting machine 3 comprises a support framework 10 mounting a reciprocable work piece in-feed table 11 which is moved back and forth on the support framework 10 by motors and control gear (not shown).

Mounted on the support framework 10 is a height adjustable carriage 12 in which is mounted a bandsaw 15, only portion of which is shown. The carriage 12 can be raised and lowered on the framework 10. Mounted forward of the bandsaw 15 is a guide roller 16. There is provided a sheet take-off conveyor 20 which is adjustable up and down by various motors and rams (not shown). The adjustable sheet takeoff conveyor 20 works in tandem with the carriage 12. A controller 60 is provided to

control the operation of the slab slicing machine 2 and the contouring machine 3.

The sheet take-off conveyor 20 has a head portion 22 for delivery to the contouring machine 3. The sheet take-off conveyor 20 is mounted adjacent the head portion 22 on uprights 23 in turn terminating in rollers 24 mounted within parallel ground engaging tracks 25.

Refernng now to Figs. 4 to 7 inclusive, the contouring machine 3 comprises a support structure 30 carrying a pair of opposed profiting rollers, namely. an upper roller 31 and a lower roller 32 for selectively compressing therebetween a rectangular sheet of foamed plastics material. Mounted on the support structure 30 is a feed-in table 33 which is fed directly from the conveyor 20. An endless bandsaw 35 having a splitter blade 36 with a cutting edge 37, is mounted midway between the rollers 31 and 32 to

srlt a compressed sheet as it progresses through the rollers. The bandsaw 35 is driven by motors 38 and has means for moving the bandsaw into and out of the rollers 31,32, namely, pneumatic rams 39. Adjacent the rotters 31 and 32 is the splitter blade 36, in a substantial V-shaped cowling 40 which houses further rams

39. Adjacent where the edge 37 of the splitter blade 36 projects from the cowEng 40, there is mounted position sensors 41. A blade sharpener 43 is provided through which the splitter blade 36 travels as it is driven. A sheet take-off conveyor 44 is

provided. Mounted on the cowling 40 is a height adjustable guide plate 45, the adjustment for which is not shown. The guide plate 45 projects upwardly and away from the splitter blade 36 to a position above the sheet take-off conveyor 44. The sheet take-off conveyor 44 in turn feeds a final take-off conveyor 46 which is ovotagy mounted on the support structure 30 and is height adjusted by pneumatic rams 47 and may be controlled by a foot pedal 61. A dust and particle extraction unit 62 is provided with an extraction pipe 63 mounted adjacent the cutting blade 36.

In operation and referring particularly to Fig. 1, a block of compressible synthetic foamed plastics material, identified by the reference numeral 50. is placed on the reciprocable work piece in. feed table 11. Firstly. the height of the block 50 is sensed and. if necessary, a small portion of the block is first cut and then succeeding rectangular sheets are cut by passing the block 60 back and forth to the blade 15 where rectangular sheets 51 are cut and delIVered up the take-off conveyor 20 to the feed-in table 33 where each rectangular sheet 51 is successively delivered to the contouring rollers 31 and 32 where each sheet 51 is compressed therebetween and

delivered against the splitter blade 36 which cuts the sheet 51 into two sheets. namely, an upper sheet 55 and a bottom sheet 56. The upper sheet 55 carries across the guide plate 45, while the bottom sheet 66 is delivered onto the take-off conveyor 45. The upper sheet 55 then slides off the guide plate 45 to mate with the bottom sheet 56 as can be seen in Fig. 5. The sheets 55 and 56 are then in mating relationship with their side edges coinciding and the peaks of one engaging the hollows of the other to form a reconstituted sheet 57.

The guide plate 45, once set in position. generally does not have to be adjusted, even where the thickness of the foamed plastics material is anything from 2.5 to 10 cm. It has been found that with the present invention, there is no need as heretofore to

have a number of operatives, firstly in feeding material into the contouring machins or, even more importantly, removing the feed and aligning the split sheets. Needless to say, suitable control equipment, etc. is provided.

By having the position of the handsaw accurately controlled, as well as ensuring that it is always sharpened, a consistent product is obtained.

In the specification the tenns acomprise, comprises, comprised and comprising* or any variation thereof and the terms "include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation.

The invention is not limited to the embodiments hereinbefore described but may be variedin both construction and detail.

Claims

CUUMS 1. A compressible synthetic foamed plastics material contouring machine assembly comprising a rectangular stab slitting machine feeding a contouring machine, the contouring machine comprising.- a support structure ; a pair of opposed meshing profiting rollers for selectively compressing, therebetween a rectangular sheet of foamed plastics material ; a feed-in table for the sheet adjacent the rotters ; a splitter blade comprising an endtess bandsaw mounted in a transverse plane midway between the rollers to slice the compressed sheet as it progresses through the rollers whereby on exiting the rollers, there are two sheets, narnely, an upper sheet and a bottom sheet respectively above and below the splitter blade, which sheets expand to form similar surfaces with alternating mutually complementary peaks and hollows ; a sheet take-off conveyor for leading the bottom sheet away from the splitter blade ; a height adjustable guide plate projecting upwardly and away from the splitter blade to a position above the take-off conveyor to deposit the upper sheet onto the bottom sheet in mating relationship with their side edges coinciding and the peaks of one engaging the hollows of the other to form a reconstituted sheet; means for sensing the position of the cutting edge of the bandsaw relative to the profiling rollers ; and means for moving the bandsaw longitudinally towards and away from

<Desc/Clms Page number 10>

the rollers in response to the relative positions of the bandsaw and the profiling rollers.
2-An assembly as claimed in claim 1, in which the rectangular slab slitting machine comprises : a support framework : a cutting blade assembly mounted on a height adjustable carrigage on the support framework ; a reciprocal work piece in-feed table for the cutting blade on the support framework ; a sheet take-off conveyor for the cutting blade having a tail portion connected to the carnage for movement therewith and having a head portion for delivery to the feed-in table for the sheet of foamed plastics material.
3. An assembly as claimed in claim 2, in which the sheet take-off conveyor is mounted on an upright support frame terminating in rollers for engagement with a pair of spaced-apart parallel ground engaging tracks.
4. An assembly as claimed in any preceding daim, in which the splitter blade mounted In a substantially V-shaped cooling having an exit slot adjacent its apex through which the cutting blade projects and in which the means for moving the bandsaw longitudinally comprises double acting pneumatic rams mounting pusher plates for engaging the non-cutting edge of the splitter blade, some of the rams being mounted within the cowing.
5. An assembly as claimed in claim 4, in which the guide plate forms an extension of the cowing.
6. An assembly as claimed in any preceding claim, in which a blade sharpener

<Desc/Clms Page number 11>

is provided for continuous sharpening of the splitter blade in use.
7. An assembly as claimed in any preceding claim, in which the sheet take-off conveyor feeds a final take-off conveyor pivotally mounted on the support structure adjacent the sheet take off conveyor and also mounted by double

acting rams on the structure for height adjustment of its end remote from the sheet take-off conveyor.
8. An assembly as claimed in claim 7. in which control means are provided to raise the height of the end of the main take-off conveyor a distance substantiallythe same asthethicknessofthereconstitute sheet.
9. An assembly substantially as described herein With reference to and as illustrated in the accompanying drawing.
10. A contoured compressible foamed plastics material manufactured by the assembly of any preceding claim.