The present invention relates to a method and related apparatus for cutting a product from a sheet material.
The cutting of predetermined shapes from a sheet material may be achieved by using a laser or fluid jet or similar. When using a fluid jet to cut such material is it very difficult to control the depth of cut accurately. Indeed normally the material is cut all the way through its entire thickness with the jet passing through the material from one side another. The sheet material is normally secured by a fixture which supports the sheet material to allow for the jet to pass from one side to the other without the jet being unnecessarily disbursed or impinging on other parts of the fixture. By way of example, a fixture may hold a sheet material above a water filled tank and from the other side of which the jet impinges onto the sheet to cut through the sheet thereafter being directed into the water filter tank to disburse any remaining jet energy.
When it comes to methods to hold the sheet material, limitations arise especially if the jet used to cut the material may, once passed through the material still has sufficient energy to cause damage to the portions of the fixture on the other side of the sheet material. Whilst the sheet material may be held at its perimeter region allowing for a clear passage of cutting fluid to pass through the sheet material and into the tank beneath, the product cut from the sheet material will subsequently fall into the tank of water from which it will need to be removed. The product cut from the sheet material floating around in the tank may become damaged from subsequent jet action being directed into the tank of water. For cutting of small squares or rectangles for example the method of fixing the sheet is of real concern as the jet needs to be able to pass freely through the sheet and then passed the fixture, into the water tank without damaging the fixture. The fixture must simultaneously be designed to support the parts once separated by the cutting action. Where the fixture is able to maintain support to the sheet by extending below and inwardly from the perimeter of the sheet, the cutting of a product from the sheet material is not a problem. However as soon as a product to be cut is to be generated entirely inwardly from the perimeter of the sheet, support by the fixture to that product to be removed from the sheet can no longer occur where the sheet and the fixture remain in a fixed relationship to each other during the cutting process.
Accordingly without providing a hole in the fixture about the product to be cut from the sheet, but to remain supported by the fixture the cutting process can not be performed without the jet also impinging on part of the fixture itself. To avoid the jet impinging on the fixture itself in such a relationship, a hole in the fixture of a greater size to the product to be cut from the sheet must be provided which, once the product is entirely cut from the sheet will result in the product from falling through and away from the fixture.
For certain cutting procedures it is also imperative that a high degree of accuracy of the items cut from a sheet is achieved to within very close tolerances. This is particularly so in relation to the cutting items from a sheet to be used in circuit board or other electronic type applications. Therefore in mounting a sheet for cutting it is desirable for the sheet to remain in a relationship to the cutting device wherein the relationship remains constant such that during a computer controlled cutting of the sheet, no margin of error can be introduced between the relative positioning of the cutting device and sheet as a result of for example the movement of the sheet between different cutting stations.
Accordingly it is an object of the present invention to provide a method and related apparatus for cutting a product from a sheet material which overcomes the abovementioned difficulties or which will at least provide the public with a useful choice.
In a further aspect the present invention consists in a method of cutting a product from a sheet material as herein described and with reference to the accompanying drawings.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
The present invention allows for a shape to be cut from a sheet material by using a line type cutting apparatus such as for example an abrasive fluid jet, laser, wire spark erosion, flame cutting or similar. With reference to
In order to cut objects from the sheet material where the entire perimeter of the cut object is within the boundaries of the sheet 1, a multi-step cutting process is employed by the present invention. In a first step, a first portion of the perimeter of the shape to be cut from the sheet is defined by cutting along the perimeter portion (whether 1 or more separate lines) by the jet when the sheet is supported by the support means in a first position. In this first position the slot 6 of the support means 2 extends to be commensurate with that portion of the perimeter of the shape to be cut by the jet. The sheet 1 is then moved to a second position where the blank then overlies a slot to be commensurate with the remaining portion of the perimeter of the shape to be cut from the sheet. In this subsequent position, the previously cut perimeter portion of the shape does not require to be commensurate with any slot of the second support region. Whilst in the most preferred form only two cutting steps are provided, first to define a first cut or cuts of a first portion of the perimeter and a second to define a subsequent cut or cuts to define the remaining perimeter portion of the shape to be cut from the blank, it is to be appreciated that more than two cutting steps may also achieve the same result. However for efficiency two cutting steps are sufficient.
In the most preferred form after the first cutting step the blank 1 is actually moved to a second support means, being a support table providing the slots to allow the jet to pass therethrough during the process of cutting the remainder of the perimeter of the shapes from the blank.
With reference to
In moving to cut along the four lines in the X direction, each cutting means 7 is firstly advanced along a feeder slot 10 extending in the Y direction. With reference to
With reference to
Alternative to using two different support means, the sheet may be repositioned on the same support means, utilising the same slots. In the example as shown in
By following the cutting pattern as for example shown in
The sheet may alternatively be supported during the first cutting process by a support means which need not necessarily provide slots beneath the lines to be cut in the sheet material, since the cuts provided during the first cutting process will not remove any of the product from the sheet material. However the support provided with commensurate slots during the cutting process, may reduce the vibrational effect by the cutting means transmitted to the sheet material. During the final cutting process the sheet material is preferably entirely supported by the supporting regions save for where the slots through the supporting means of the second supporting region are provided.
In
In use a sheet material is placed on the first support means 102A as for example shown in
During cutting of the sheet in the first cutting procedure, a path as for example shown in
In preparation for the second cutting procedure the support table 102b is moved to become positioned beneath the sheet material. However the sheet material still remains, and in addition, supported by the first support means 102a. The support table 102b merely positions itself to be located beneath the opening 150 of the first support means 102a. The support table is able to move in the X direction and in the Z direction so as to be positioned accordingly. The support table provides slots there through which are commensurate with the path to be cut by the cutting means through the sheet material in the second cutting procedure. The path to be cut during the second cutting procedure is as for example shown in
The benefit of maintaining the sheet material on the first support means for both the first and second cutting procedure is that no transfer of the sheet material is required to be made to a different support means. The support table merely positions itself to be relied upon in conjunction with the first support means for the second cutting procedure whilst the sheet material still remains in a fixed relationship relative to the first support means. With the provision of such location means as the support pins the sheet material can remain accurately positioned relative to the cutting means thereby ensuring that an accurate repeat of cut is able to be provided.
Number | Date | Country | Kind |
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PCT/SG02/00297 | Dec 2002 | SG | national |
200108105-8 | Dec 2001 | SG | national |
Number | Date | Country | |
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Parent | 10500273 | May 2005 | US |
Child | 11748010 | May 2007 | US |