GB2154529A - Apparatus for the mechanical treatment of workpieces by a jet or beam - Google Patents

Abstract

A driven conveying apparatus (1) is provided with interchangeable supports (3) arranged at uniform intervals from one another. Each support (3) comprises an angled metal sheet which is suspended between two conveyor belts (2). A plurality of such supports (3) form a grid on which the workpiece to be treated rests. Edge (8) of the support (3) is bevelled, and the tip is rounded. The supports (3) are angled in such a way that scattered beams or jets are deflected in a desired direction, where they cannot do any damage. In a modification the supports are disposed in a holder which is particularly suitable for work preparation, outside the apparatus. The apparatus is used particularly advantageously for cutting by laser beams. <IMAGE>

Description

SPECIFICATION Apparatus for the mechanical treatment of workpieces by a jet or beam The invention relates to an apparatus for the mecha nicaltreatmentofworkpieces by a jet, beam or the like and particularly but not exclusively to treatment by a laser.

In the case of the treatment of workpieces by means of laser beams, water jets etc, it is known to deliver continuously the workpieces to be treated on a conveyor belt to a cutting tool. In this connexion the bed on which the workpiece rests is subjected to considerable wear and must frequently be replaced.

Damage occurs very quickly when cutting with beams, in particular with laser beams, which on account of the high intensities in a very small space are used for drilling, cutting and welding in very small sizes. On account of the extremely high energy densities in the order of magnitude of some 1013 W/cm2, the safety requirements for the operating personnel must also be set at a high level in order to prevent injuries due to scattering of the beams or jets.

It is already known to intercept, on grounds of safety, the scattered rays, which occur during welding with laser beams, by means of a ray tray which comprises a cooled chamber blacked-out on all sides (European Application 0 094 346).

According to the invention, interchangeable supports are mounted in suspension on the conveying apparatus.

The supports may be directly suspended from the conveyor apparatus at uniform intervals from one another or contained in a holder itself suspended from the conveying apparatus.

"Cutting" as used herein means any type of material removal, and includes removal of material such as by burning, friction or abrasion.

It is thus possible to largely prevent destruction of the supports or the conveying devices for the workpieces to be machined. In addition, the safety of the operating personnel can be increased to a considerable degree.

The use of a holder permits a desired work preparation, in particular when treating parts which cannot be delivered in the form of a strip or plate. In addition, the stoppage time of the plant can thus be reduced.

It is advantageous to provide at least two conveyor belts. The latter are provided with suspension appar atus for the replaceable supports. The suspension apparatus can comprise hooks which are secured to hinges for example. However, any other suspension apparatus, which permits rapid replacement of the supports, can also be provided.

It is advantageous to manufacture the supports at least partly from metal and preferably from a metal which can be easily worked by bending or deformation.

It is advantageous to produce the metal sheet of the support as a vertical component in the region of its support edge and to bend the central and lower part in such a way that the residual energy of the treatment jets or beams is deflected downwards by reflexion, for example into a box in the machine. The bend in the metal part gives the support the necessary transverse stability.

In accordance with a preferred embodiment, all angles a' and a" are between 200 and 400.

It is advantageous to bevel the edge which comes into contact with the workpiece and which represents the vertical part of the support. In this connexion the bevel can be provided on one side to form a sloping surface or on both sides as a taper. The tips are preferably flattened to approximately 0.5 mm in width or diameter. The angle of inclination a amounts to between 200 and 40 , preferably 300.

It is advantageous to use aluminium or copper as the material for the support. Both metals permit an economical manufacture of the supports on a bending press and ensure good heat dissipation. Sheet strips of aluminium have proved to be best for radiation machining.

It is recommended to use metal sheets for supports with a constant wall thickness. In this connexion wall thicknesses of from 2 to 5 mm, preferably of 3 mm, have proved to be best.

The support may be constructed in such a way that it can be used in a double-ended manner. This has the advantage that over a period of time, during which wear has possibly occurred, it is merely necessary to rotate the support through 1800. In this way the service life can be doubled.

Advantageously, a base, which collects waste material and cuttings, is provided in the cartridge.

The cartridge can be emptied after machining in a simple manner, outside the machine.

The modification, according to claim 12, is likewise used for the effective removal of material, but, on account of the gas deflexion and/or suction provided, for example also by means of a double base, it can be used for the recovery of cutting and/or protection gases.

The apparatus is preferably used for cutting by means of laser beams: the protection gas can pass without difficulty through the individual supports.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an overall view of one embodiment of apparatus according to the invention; Figure 2 is a view of one side of a support lamella of the conveying apparatus of Figure 1; Figure 3 is a section through the support lamella of Figure 2 in the vicinity of its suspension; Figure 4 shows a modified support lamella which can be used in a double-ended manner, and Figure 5 is a perspective view of a holder or cartridge with a support lamella therein.

Conveying apparatus 1, which comprises at least two conveyor belts 2 (only one shown), is shown diagrammatically in Figure 1. The conveyor belts 2 are in the form of chains each of which is driven by a first sprocket wheel 4 and is reversed by a further sprocket wheel 5. Hinges (not shown), by which lamellar supports 3 are detachably suspended, are provided on the insides of the conveyor belts 2.

Workpieces 6, 6', 6" are carried on the upper runs of the conveying apparatus by the supports 3, the workpiece 6" being shown disposed below a cutting apparatus 7.

Referring now to Figures 2 and 3 the support 3 shown therein has a bevelled support edge 8 which leads into a vertical portion 11, having openings 10, preferably in the form of eyelets, for suspension on the hinges (not shown) of the conveyor belts 2. The portion 11 leads into an angled central portion 12 and the central portion 12 leads into an angled lower portion 13.

Figure 4 shows a support 3 which can be used with either and uppermost. In addition to the common portion 13 a support edge 8' with a bevelled portion 9' is provided at each end of the support in a mirror-inverted manner. The bevelled portions 9' are formed on both sides of the support to form a taper, the tip of the taper being rounded, for example to form a curved surface of 0.5 mm in diameter.

If necessary, a vertical portion 11' and an angled central portion 12' have the same function as the portions 11 and 12. The angles a, a' and a" are each between 20 and 40 , and are preferably 30 .

The holder or cartridge 14, illustrated in Figure 5 and in its simplest form comprising a frame of angled section, likewise is provided with supports 3 as described above. The holder 14 has lugs 16 on its longitudinal sides for suspending the holder in the conveying direction.

The preferred embodiment illustrated has a base 15 formed obliquely to a suction bore 17. The supports 3, suspended at irregular intervals matching the shape of the workpiece, likewise in the form described above, have edges 8, as already illustrated in Figure 3.

Instead of suspended supports 3, the latter can be firmly secured to the frame of the holder, while the entire holder is suspended in the conveying apparatus.

A particularly favourable recovery of the protective gas can be achieved by way of the suction bore 17 when using a double base 15 and/or baffle plates and/or collector for the waste material.

The apparatus according to the invention represents an economical and simple solution to the conveying of workpieces to a cutting apparatus. It makes it possible to work without destroying the support bearing the workpiece to be treated and substantially meets the safety requirements for the operating personnel for radiation cutting apparatus of all types. The cutting apparatus can include those using jets of liquids, for example water, or solids such as sand. The apparatus has proved successful when used in laser cutting plants.

Claims (14)

1. Apparatus for the treatment of workpieces by a jet, a beam, or the like, comprising a cutting apparatus and a driven conveying apparatus, wherein interchangeable supports are mounted in suspension to the conveying apparatus at uniform intervals from one another.

2. Apparatus for the treatment of workpieces, by a jet, a beam or the like, comprising a cutting apparatus and a driven conveying apparatus, wherein supports are mounted on the conveying apparatus in a holder or cartridge.

3. Apparatus according to claim 1, wherein the conveying apparatus comprises at least two conveyor belts provided with means for suspending the supports.

4. Apparatus according to anyone of claims 1 to 3, wherein the supports consist at least partly of a metal sheet.

5. Apparatus according to claim 4, wherein the metal sheet of the support consists of at least one vertical portion with a support edge, a central portion inclined at a first angle to the vertical portion and a lower portion inclined at a second angle to the vertical portion.

6. Apparatus according to claim 5, wherein the first and second angles are between 20 and 40 .

7. Apparatus according to claim 5 or claim 6, wherein each support has at least one bevel at the free edge of its vertical portion.

8. Apparatus according to any one of claims 4 to 7, wherein the metal sheet comprises at least one support of aluminium or copper.

9. Apparatus according to anyone of claims 1 to 8, wherein each support has a constant wall thickness.

10. Apparatus according to anyone of claims 1 to 9, and constructed in such a way that it can be used with either end uppermost.

11. Apparatus according to claim 2, wherein the holder or cartridge has at least one base.

12. Apparatus according to claim 11, wherein a material and/or gas deflexion and/or suction means is provided in the vicinity of the base.

13. Apparatus according to anyone of claims 1 to 12, when used for cutting by means of a laser beam, which is coaxially surrounded by an inert or reactive gas in the vicinity of its focal surface.

14. Apparatus for the mechanical treatment of workpieces, substantially as hereinbefore described with reference to, and as shown in Figures 1-3, or Figure 4, or Figure 5 of the accompanying drawings.