NZ522758A

NZ522758A - Luminescent marking of piece to be cut or welded

Info

Publication number: NZ522758A
Application number: NZ522758A
Authority: NZ
Inventors: Dennis James O'connell
Original assignee: Dennis James O Connell
Priority date: 2000-04-26
Filing date: 2000-06-30
Publication date: 2004-09-24
Also published as: WO2001081037A1; AU2005100981A4; CA2445544A1; EP1294525A1

Abstract

Products for aiding welding or high temperature cutting operations comprise a work piece marker and a welding or cutting aid system. The marker includes a luminescent material which is excited by UV radiation generated during arc welding to emit light in the visible spectrum, e.g. orange light. The aid system includes a light filter matched to the visible emission wavelength of the marker interposed in the light path, adjacent the dark filter of a welder's mask. The marker is used to mark a weld or cutting path trace visible to the welder during the operation. A method of aiding a welding or cutting operation using the marker and matched light filter is also provided.

Description

New Zealand Paient Spedficaiion for Paient Number 522758 522 7 58 i AID FOR WELDING Field of the Invention This invention relates to products and methods for aiding welding.

Background of the invention Prior to welding operations, it is known to use chalk as a marker for creating markings on a workpiece, such as the path which the weld is to follow. However the mask which the operator interposes to protect the eyesight includes a dark filter to substantially attenuate the very intense electromagnetic radiation from the welding site. This can make it very difficult or impossible for the operator to see the chalk markings during the welding operation. As a result, the weld is frequently inaccurate and sometimes it is necessary for the operation to be performed again to achieve the required standard of accuracy or neatness. Also, the difficulty of seeing the chalk markings often means that the operator stops the operation, removes the mask to inspect the progress of the operation before resuming. These interruptions can significantly increase the time taken for the welding operation.

Object of the invention It is an object of the present invention to provide products and methods which can enable a person carrying out a welding operation to see markings on a workpiece during the welding operation.

Summary of the Invention According to a first aspect of the invention there is provided a welding aid system for aiding a welding operation, the system including: a workpiece marker which includes a luminescent material in a form or medium for application to a workpiece, the luminescent material having the property of enabling creation of markings on the workpiece and the welding operation generating exciting radiation to stimulate the luminescent material to emit visible radiation so that the markings are visible during the welding operation through eyesight protecting means of the operator, and 2 a light filter to be interposed in use between the workpiece and the operator's eyes, the light filter being translucent to frequencies which match the frequency or frequencies of visible light emission of the luminescent material of the marker, the light filter substantially attenuating radiation at frequencies spaced from said frequencies of visible light emission of the luminescent material.

According to a second aspect of the invention there is provided a method of aiding a welding operation being carried out on a workpiece, the method including the steps of: applying to the workpiece a luminescent material so as to create markings on the workpiece at locations intended to guide or inform an operator monitoring or controlling the welding operation, the luminescent material having the property of emitting visible radiation when excited during the welding operation, and conducting a welding operation on the workpiece while viewing the workpiece through an eyesight protector apparatus, the eyesight protector apparatus being translucent to frequencies which match the frequency or frequencies of visible light emission of the luminescent material and substantially attenuating radiation at frequencies spaced from said frequencies of visible light emission of the luminescent material, and controlling the welding operation in accordance with the visible markings of luminescent material on the workpiece.

Description of the Preferred Embodiments In the embodiments of the invention, preferably the luminescent material which enables creation of markings on the workpieces emits radiation in the visible spectrum upon excitation during the welding operation. In particular, it is preferable that the welding operation generates the exciting radiation which stimulates the luminescent material to emit the visible radiation.

The products and methods of the present invention are particularly applicable to arc welding including stick welding, TIG welding and MIG welding operations. It is possible f ' V that the principles of the invention may be applicable to other types of welding operations but the radiation generated in other types of welding and cutting may not be as readily amenable to stimulating or exciting a luminescent material to emit sufficient light in the visible part of the spectrum. In the preferred or expected principal field of use in which the welding 5 operation includes generation of an electric arc, the radiation being emitted by the arc preferably constitutes the exciting radiation which impinges on the luminescent material to stimulate it to emit the visible radiation. For example, the luminescent material may be excited by ultraviolet radiation emitted by the electric arc to emit the visible radiation. The luminescent material may be a fluorescent material, or may be a phosphorescent 10 material.

Preferably the luminescent material emits visible radiation in the middle or higher wavelengths of the visible spectrum, particularly in the yellow to orange to red regions of the visible spectrum. The luminescent material may for example emit light predominantly in the range of wavelengths from 580 nm to 660 nm, e.g. primarily at or around about 620 nm 15 (orange-red). The yellow to orange to red region of the visible spectrum is preferred since it is found that these colours are more readily visible in or through the fume or smoke created during the welding operations than colours towards the blue-violet end of the spectrum.

Suitable luminescent materials can be chosen from organic and inorganic materials, and from liquid or solid formulations, having the required excitation and emission properties. 20 Organic dyes known as "daylight fluorescent pigments" can provide suitable markers.

Rhodamine and fluorescein dyes may be suitable, although specific and optimum fluorescent materials have not been identified at this stage of development. It is expected however that an ordinarily skilled chemist could readily identify suitable materials by reference to published properties for luminescent materials or by routine empirical testing. 25 The workpiece marker preferably further includes a filler mixed with the luminescent material. The filler may be a solid material whereby the workpiece marker can be held by 4 hand and manipulated by a user to apply the markings to the workpiece. Preferably, the filler itself creates a marking on the workpiece which is visible in daylight or other illumination conditions enabling human visibility of the markings formed by the filler. The filler may comprise chalk in a particulate form mixed with the luminescent material. In the case of a 5 luminescent material in solid solution or suspended in a solid transparent material such as an organic resin, the chalk may be mixed in a proportion of 60% by weight with 40% by weight of the resin/luminescent material particles.

The workpiece marker may further include a binder which binds the luminescent material in a solid form which can be held and manipulated by a user to apply the markings 10 to the workpiece. The binder may comprise a resin material which is substantially translucent to the visible radiation emitted by the luminescent material making the markings on the workpiece visible during the welding operation. A suitable resin binder may be a thermosetting or thermoplastic resin binder. Melamine sulphonamide formaldehyde resin may be suitable as a carrier or medium for the luminescent material and/or as a binder for the 15 chalk and active material mixture.

The light filter preferably includes a panel of coloured light filter material to be interposed in use between the workpiece and the eyes of the operator, the panel being arranged to be mounted by the eyesight protecting means through which the operator views the welding operation. In the case of a conventional eyesight protecting means which 20 comprises a mask having a window through which the operator views the welding operation, the window is provided with a dark filter medium interposed in the light path to reduce the intensity of light from the welding operation reaching the operator's eyes, and is also provided with the light filter additionally interposed in the light path from the site of the welding operation to the operator's eyes. The dark filter may be the conventional dark glass 25 which cuts out ultraviolet and infrared radiation and substantially attenuates visible radiation so as to protect the operator's eyes. The light filter can be also a panel, e.g. of the standard "6 JULM f 180 mm by 50 mm size, to fit into the mountings provided by welder's masks for the dark filter. The light filter is desirably selected to pass light at frequencies or wavelengths which the dark filter also passes and also if desired to substantially attenuate UV and/or IR radiation. The frequencies that the light filter passes preferably match the visible emission 5 frequencies of the luminescent material. For example for luminescent material emitting at a wavelength of about 620 nm, an orange-red light filter would be preferred.

The light filter may be a lighting gel of the kind used for projecting coloured light such as in theatre stage lighting, the lighting gel having a characteristic colour substantially matched to the colour of visible light emission of the luminescent material. For the suggested orange-red 10 luminescent material emissions, an "Amber-rose No. 22" gel filter is suitable.

The light filter enhances the visibility of the markings on the workpiece by attenuating or cutting out other wavelengths and helping the operator's eyes be more sensitive to the wavelength of the emissions from the luminescent material.

Also as mentioned above in the summary of the invention, the second aspect of the 15 invention provides a method of aiding a welding operation being carried out on a workpiece, the method including the steps of: applying to the workpiece a luminescent material so as to create markings on the workpiece at locations intended to guide or inform an operator monitoring or controlling the welding operation, the luminescent material having the property of emitting visible radiation, when excited during the welding operation, and 20 conducting a welding operation on the workpiece while viewing the workpiece through an eyesight protector apparatus, the eyesight protector apparatus being translucent to frequencies which match the frequency or frequencies of visible light emission of the luminescent material, and controlling the welding operation in accordance with the visible markings of luminescent material on the workpiece.

The most common situation for application of the method of the invention would be where the visible markings applied to the workpiece define or at least include a welding nath ,nte^Rpr&perty ; - 6 JUL 2004 DCnr

Claims

which the welding operation is to follow. However, other marks such as prompts for the nature or location of the welds can also be used. In the preferred method the steps of applying the markings and conducting the welding operation comprises using an aid system according to the first aspect of the invention by application of markings to the workpiece using the workpiece marker of the aid system and interposing the light filter in the light path during the welding operation. It is to be understood that various alterations, modifications and/or additions may be made to the features of the possible and preferred embodiment(s) of the invention as herein described without departing from the spirit and scope of the invention as defined in the following claims. intellectual property office of n.z j -6 JUL 2004 RECEIVED CLAIMS

1. A welding aid system for aiding a welding operation, the system including: a workpiece marker which includes a luminescent material in a form or medium for application to a workpiece, the luminescent material having the property of enabling creation 5 of markings on the workpiece and the welding operation generating exciting radiation to stimulate the luminescent material to emit visible radiation so that the markings are visible during the welding operation through eyesight protecting means of the operator, and a light filter to be interposed in use between the workpiece and the operator's eyes, the light filter being translucent to frequencies which match the frequency or frequencies of 10 visible light emission of the luminescent material of the marker, the light filter substantially attenuating radiation at frequencies spaced from said frequencies of visible light emission of the luminescent material.

2. A system as claimed in claim 1 wherein the light filter includes a panel of coloured light filter material to be interposed in use between the workpiece and the eyes of the 15 operator, the panel being arranged to be mounted by the eyesight protecting means through which the operator views the welding operation.

3. A system as claimed in claim 2 wherein the eyesight protecting means comprises a mask having a window through which the operator views the welding operation, the window being provided with a dark filter medium interposed in the light path to reduce the intensity 20 of light from the welding operation reaching the operator's eyes, the light filter being additionally interposed in the light path from the site of the welding operation to the operator's eyes.

4. A system as claimed in claim 2 or 3 wherein the light filter is a lighting gel of the kind used for projecting coloured light such as in theatre stage lighting, the lighting gel 25 having a characteristic colour substantially matched to the colour of visible light emission of the luminescent material. intellectual property office of n.z - 6 JUL 2004 BBAC!h / r-r\ 8

5. A system as claimed in any one of claims 1 to 4 wherein the marker consists of a workpiece marker which includes a filler mixed with the luminescent material.

6. A system as claimed in claim 5 wherein the filler is a solid material whereby the workpiece marker can be held by hand and manipulated by a user to apply the markings to 5 the workpiece.

7. A system as claimed in claim 5 or 6 wherein the filler itself creates a marking on the workpiece which is visible in daylight or other illumination conditions enabling human visibility of the markings formed by the filler.

8. A system as claimed in any one of claims 5 to 7 wherein the filler comprises chalk in 10 a particulate form mixed with the luminescent material.

9. A system as claimed in any one of claims 5 to 8 and further including a binder which binds the luminescent material in a solid form which can be held and manipulated by a user to apply the markings to the workpiece.

10. A workpiece marker as claimed in claim 9 wherein the binder comprises a resin 15 material which is substantially translucent to the visible radiation emitted by the luminescent material making the markings on the workpiece visible during the welding operation.

11. A method of aiding a welding operation being carried out on a workpiece, the method including the steps of: applying to the workpiece a luminescent material so as to create markings on the 20 workpiece at locations intended to guide or inform an operator monitoring or controlling the welding operation, the luminescent material having the property of emitting visible radiation when excited during the welding operation, and conducting a welding operation on the workpiece while viewing the workpiece through an eyesight protector apparatus, the eyesight protector apparatus being translucent to 25 frequencies which match the frequency or frequencies of visible light emission of the intellectual property office of n.z - 6 JUL 2004 RECEIVED 9 luminescent material and substantially attenuating radiation at frequencies spaced from said frequencies of visible light emission of the luminescent material, and controlling the welding operation in accordance with the visible markings of luminescent material on the workpiece. 5

12. A method as claimed in claim 11 wherein the visible markings applied to the workpiece include a welding path which the welding or cutting operation is to follow.

13. A method as claimed in claim 11 or 12 wherein the steps of applying the markings and conducting the welding operation comprise using an aid system as claimed in any one of claims 1 to 10 by application of markings to the workpiece using the workpiece marker of the 10 aid system and interposing the light filter in the light path during the welding operation.