AU673087B2

AU673087B2 - Fume extraction device

Info

Publication number: AU673087B2
Application number: AU68769/94A
Authority: AU
Inventors: David Osborne
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-06-26
Filing date: 1994-07-27
Publication date: 1996-10-24
Anticipated expiration: 2011-06-21
Also published as: AU6876994A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): DAVID OSBORNE Invention Title: FUME EXTRACTION DEVICE The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 FUME EXTRACTION DEVICE This invention relates to a fume extraction device and, in particular, to a fume extraction device for use with welding equipment such as a MIG welder.

Fume extraction devices are known for use with welders to remove fumes which are created during welding so that the person using the welder does not breathe those fumes. However, conventional fume extraction equipment is very expensive and is also very bulky utilizing a considerable number of moving parts. Thus, in view of the expensive conventional equipment and their bulky nature which makes them difficult to move and use, they are not used as often as they should be or if used, are used with some difficulty.

The object of this invention is to provide a fume extraction device which overcomes the above problems.

The invention provides a fume extraction device for a welder which has a hand piece and a torch, the extraction device including: an inlet conduit having an inlet opening and an outlet for location relative to the torch so that the inlet opening is adjacent the torch and the outlet is remote from the torch; a second conduit coupled to the inlet conduit 25 between the inlet opening and the outlet, the second conduit being for connection to a source of compressed air; an electrically operated valve for selectively allowing and preventing flow of air through the second conduit; a control means for providing a signal to the valve to selectively open or close the valve; and wherein when compressed air is supplied to the second conduit, the compressed air flows along the second conduit and into the first conduit to the outlet to create a suction through the inlet opening to extract fumes, stafffida/keepspec/68769.94 22.8.96 3 created during a welding operation, away from the hand piece and torch of the welder.

The invention also provides a welder including: a hand piece; a torch coupled to the hand piece for performing a welding operation on a workpiece; an inlet conduit having an inlet opening and an outlet, the inlet opening being adjacent the torch and the outlet being positionable at a remote location with respect to the torch; a second conduit coupled to the first conduit between the inlet opening and the outlet, the second conduit being for connection to a source of compressed air; an electrically operated valve for selectively allowing and preventing flow of air through the second conduit; control means for providing a signal to the valve to selectively open or close the valve; and wherein during a welding operation, compressed 20 air is supplied through the second conduit to create suction in the first conduit so that fumes created during welding are extracted through the inlet opening into the inlet conduit and drawn to the outlet at the remote 2 location.

25 Since the device utilizes a flow of pressurized fluid to create the suction, moving parts are not required in the apparatus and the apparatus is simple and light.

Thus, it can be easily used in conjunction with a welding torch or the like to extract fumes created during welding.

Furthermore, in view of the simple nature of the device it is relatively inexpensive compared to conventional equipment.

Preferably, control means is a timer and the valve is a solenoid valve which is controlled by the timer such that said valve remains open to allow the suction to be maintained through the inlet to the first conduit for a statfridafkeep/spec/68769.94 22.8.96 3a predetermined amount of time after the activity which creates the fumes ceases to ensure that fumes are sucked into the device after the activity ceases.

Preferably the second conduit also includes a regulator for regulating the amount of fluid flow through the second conduit and therefore into the first conduit.

Preferably the first conduit includes a venturitype transducer to which the second conduit is coupled to cause the pressurized fluid to flow through the transducer to create the suction in the first conduit.

Preferably, said device is used in conjunction with a welder and said first conduit includes attachment means for attaching the first conduit to a welding torch of the welder so that the inlet to the first conduit is in proximity to the tip of the welding torch, said timer comprising a timer within the welder for producing a signal to open said solenoid when the welding torch is activated and to maintain the solenoid open for a predetermined time after the welding torch is deactivated.

20 In some embodiments, it may be desirable for the "timer to open the solenoid a predetermined time after welding commences to ensure that an arc and shielding gas

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stafffidafeep/spec/68769.94 22.8.96 4 is established before suction commences. However, tests have shown that in normal applications it is quite adequate for the suction to commence at the same time as the torch is activated to strike the arc.

The invention also includes a welder having a fume extraction device as described above.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a schematic diagram of the device embodying the invention; and Figure 2 is a more detailed view of part of the device of figure 1.

With reference to figure 1, a MIG welder 10 is shown which has a welding torch 12 which includes a handpiece 14 and a trigger 16. The handpiece 14 is connected to the welder 10 by a hose 18 through which shielding gas such as carbon dioxide or argon is supplied from a source (not shown) to the tip of the torch 12 and also through which wire 20 extends and is driven.

The preferred embodiment of the invention includes a conduit 30 which is in the form of a flexible hose. The conduit 30 has an inlet 32 and includes suitable attachment clips 34 for coupling the conduit 30 to the 25 torch 12. Preferably the attachments couple the conduit to the pipe 15 which extends between the handpiece 14 and the tip 17. Attachment of the coupling clips 34 to this part of the torch enables the conduit 32 to easily pivot or swing about the pipe 15 so that it does not interfere with a person's grip on the handpiece 14 or the welding operation and at the the same time always ensuring that the inlet 32 is in close proximity to the tip 17 for fume extraction.

A second conduit 40 communicates with the iconduit 30 at a location remote from the tip 32. The first conduit 40 is coupled to a compressor 50 and includes a solenoid 52 and a regulator 54. The solenoid 52 and regulator 54 may be attached to the MIG welder 10 and are shown separate from the MIG welder 10 in the drawing simply for clarity purposes. The conduit 30 includes a Va. 0.

I\A' b ~u venturi-type transducer 60 to which the conduit 40 is coupled. The transducer 60 is best shown in figure 2 and is of known design and generally includes t=nd flanges 62 which support O-rings 64 for sealing the transducer within the sleeve 63 inserted into the conduit 30. The transducer has a reduced diameter section 66 which flares outwardly to a wider body portion 68. Holes 70 are provided in the portion of the transducer 60 between the reduced diameter section 66 and the larger diameter section 68. An annular space 70 is created around the reduced diameter section 66 and the second conduit 40 communicates with that space.

When compressed air is supplied through the conduit 40 it is forced throngh the holes 70 as shown by the arrows in figure 2 and creates a suction in the direction of arrows 15 A. This creates a suction through the inlet 32 to therefore draw fumes created during welding into the conduit 30 so that they can be discharged through an outlet 35 of the first conduit 30 which may be provided with ero suitable filters or the like to clean the flow of air before it is discharged to atmosphere.

The solenoid 52 is controlled via a timer "which preferably is part of the MIG welder Conventionally, MIG welders 10 include a burn back timer which is used to set a predetermined time for maintaining the wire 20 running after the trigger 16 is depressed. The delay time may be half a second so that the solenoid valve 52 is therefore provided with power to maintain it open for a period of half a second after the trigger 16 is released.

This, of course, maintains the flow of pressurized fluid from the compressor 50 through the first conduit 40 and into the transducer 60 for half a second after the trigger 16 is released and welding stops to maintain the suction in conduit 30 to ensure that fumes created after welding ceases are also drawn into the conduit Thus, in order to use the device, it is simply clipped onto the welding torch 12 and may swing about the welding torch 12 by virtue of the attachments 34 so that the person using the equipment can easily grip the handgrip and ensure that the conduit 30 does not interfere with the workpiece being welded whilst at the same time ensuring 6 that the inlet 32 is still in close proximity to the tip 17 of the welding torch. In order to commence welding, the trigger 16 is depressed which operates the timer to start the wire 20 running, supply current to the wire for striking an arc and also commences the supply of shielding gas to the tip 17. The output from the timer 80 on the line 90 also opens the solenoid 52 so that the compressor supplies compressed air through the conduit 40 into the transducer 60 to create the suction in the conduit 30 for drawing fumes into the conduit 30. Thus, during welding the fumes which are created are drawn into the conduit and do not contaminate the working environment and are therefore not breathed by an operator. When welding is to cease the trigger 16 is released and this shuts off the 15 supply of power and shielding gas. The timer 80 ensures that power is still supplied to the mechanism which keeps the wire 20 running to ensure that a supply of power is maintained at the tip 17 and also supplies power on line to the solenoid 52 to maintain the solenoid 52 open for the short amount of time to maintain the flow of gas through the conduit 40 and therefore the suction in the conduit so that the fumes which continue slightly after welding ceases are also sucked into the conduit 30. After the delay time of, for example, half a second the timer 25 shuts off power supply to the solenoid 52 so that it is closed to shut off the flow of gas through the conduit and into the venturi-type transducer In some embodiments, a second timer or the timer can delay the supply of power to the solenoid 52 so that suction through the conduit 30 does not commence for a short time after welding commences to ensure that the supply of shielding gas is properly established before suction commences. However, tests have shown that for most applications it is not detrimental to commence the suction through the conduit 30 at the same time as the trigger is depressed to start the welding operation.

If desired, the conduit 30 could be arranged such that the hose 18 enters the conduit 30 through a sealed opening to run through the conduit 30 back to the MIG welder 10 to reduce the number of conduits or hoses in the 7 workplace and to make the device more tidy and compact. In other embodiments the conduit 30 could be arranged such that it surrounds the tip 17 and is generally integral or a part of the torch 12.

Since most workshops or other establishments which operate welding equipment normally include a compressor, the device can be purchased very inexpensively and also is reliable and compact.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

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Claims

3. The fume extraction device according to any one of the proceeding claims including a regulator in the second conduit between the first conduit and the valve for regulating the amount of air flow through the second O S/ conduit. j tV// >2.9 A 3, staf/ida/keepspec68769.94 22.8.96 9
4. The fume extractor according to any one of the preceding claims wherein the second conduit is coupled to the first conduit by a venturi transducer. A welder including: a hand piece; a torch coupled to the hand piece for performing a welding operation on a workpiece; an inlet conduit having an inlet opening and an outlet, the inlet opening being adjacent the torch and the outlet being positionable at a remote location with respect to the torch; a second conduit coupled to the first conduit between the inlet opening and the outlet, the second conduit being for connection to a source of compressed air; an electrically operated valve for selectively allowing and preventing flow of air through the second conduit; control means for providing a signal to the valve to selectively cpen or close the valve; and wherein during a welding operation, compressed air is supplied through the second conduit to create suction in the first conduit so that fumes created during welding are extracted through the inlet opening into the inlet conduit and drawn to the outlet at the remote .go. location.
6. The welder according to claim 5 wherein the control means is a timer maintains the valve open for a predetermined time period, after power supply to the torch of the welder ceases, so as to maintain the flow of compressed air through the second conduit and into the first conduit to extract fumes created after welding ceases.
7. The welder according to any one of the proceeding stafldalkeop/spec/68769.94 22.8.96 10 claims including a regulator in the second conduit between the first conduit and the valve for regulating the amount of air flow through the second conduit.
8. The welder according to any one of the preceding claims wherein the second conduit is coupled to the first conduit by a venturi transducer. Dated this 22nd day of August 1996 David OSBORNE By his Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. 0 0 0 a a 0 2 staffidafleeplspod68769.94 22.8.8 ABSTRACT A fume extraction device 3 isclosed for use with a welder and for extracting fumus created during welding. The device comprises a conduit (30) having an inlet Conduit (30) also includes a transducer which is coupled to a second conduit (40) for supplying compressed air to the transducer Supply of compressed air to the transducer (60) creates a suction through the conduit (30) so that fumes are drawn into the conduit A solenoid valve (52) is provided in the conduit (40) for selectively shutting off supply of s. compressed air from the compressor (50) and the solenoid valve (52) may be controlled by a timer (80) in the welder. a. *eo