WO2010028645A1

WO2010028645A1 - A welding torch and a method of adjusting the position of the gooseneck relative to the handle

Info

Publication number: WO2010028645A1
Application number: PCT/DK2009/000191
Authority: WO
Inventors: Peter Theodosiussen; Kjeld Johansson
Original assignee: Svejsemaskinefabrikken Migatronic A/S
Priority date: 2008-09-11
Filing date: 2009-08-27
Publication date: 2010-03-18
Also published as: DE112009003684T5; CN102149504B; DE112009003684B4; DK200801274A; CN102149504A; DK176936B1

Abstract

When, according to the invention, the handle (2) and the connecting element (5) on a welding torch (1 ) are equipped with a toothed rim (13, 14) each or segments (15, 16) of a toothed rim, and these are configured so as to be capable of engaging each other, and the handle is simultaneously equipped with a locking mechanism (11 ), it is ensured that it is possible to perform an adjustment of the position between handle and gooseneck, thereby allowing an optimum welding position to be selected. The invention moreover ensures that all problems of leaky gaskets are avoided.

Description

A WELDING TORCH AND A METHOD OF ADJUSTING THE POSITION OF THE GOOSENECK RELATIVE TO THE HANDLE

The invention relates to a welding torch, in particular for MIG/MAG welding machines, said welding torch being connected with a welding machine by a welding hose and comprising a handle formed by two shell parts, in which a connecting element for wire, gas, cooling air or cooling water is arranged, and wherein a gooseneck equipped with a nozzle arrangement is additionally connected, and wherein the handle moreover comprises a rotatable member through which the welding hose is passed into the handle to the connecting element, as well as a control current switch.

The invention also relates to a method of adjusting the position of the gooseneck relative to the handle.

The prior art

For a good welding result to be achieved, there are several factors which have to be considered. Not only is it necessary to select the correct welding technique, the correct current strength, wire and amount of gas, but also the welding position plays an important part for the result and not least for the working environment for the welder.

Welding tasks frequently present the problem that the welds have to be placed on faces which may be oriented spatially differently. In case of difficult welding positions, the welder will therefore wish to be able to rotate the gooseneck relative to the handle in order to get a better working position and improved ergonomics and thereby relief of wrist joints, elbow joints and shoulder joints.

Through many years it has been possible to buy welding torches in which a rotatable member is inserted on the gooseneck outside the handle. The rotatable member is made of two coupling parts having a complicated configuration, which is to ensure that the channels for gas and water remain intact upon rotation of the gooseneck. Seals for both gas and water are in- traduced internally in the rotatable member.

This welding torch has a number of drawbacks. It is relatively heavy compared with a welding torch without a rotatable member. The seals are made with a set of O-rings, which means that the seals have to be checked fre- quently for wear, as a leakage will result in a weld which is defective. This type of welding torch is expensive, and, therefore, it has only been used to a limited extent. However, user surveys show that the need is present, and that the function is in request.

The document EP0917923 A2 relates to a welding torch which comprises a handle formed by two shell parts, in which a connecting element for wire, gas, cooling air or cooling water is arranged, and to which a gooseneck equipped with a nozzle arrangement is additionally connected, as well as a control current switch.

The gooseneck may be rotated up to 360 degrees relative to the rest of the handle. Therefore, the front holder is equipped with distribution holes for gas and cooling water, and a rubber gasket is inserted between this holder and the gooseneck as a sealing element. Therefore, this structure is vitiated by problems of wear and leakages.

The object of the invention

It is the object of the invention to remedy these many defects, and this is achieved in that each of the handle and the connecting element is equipped with a toothed rim or segments of a toothed rim configured to engage each other, and that the engagement is locked by a locking mechanism arranged on the handle.

When a toothed rim is introduced, as stated, it is advantageously ensured that the position between the handle and the gooseneck may be adjusted merely by releasing the locking mechanism. Further, it is ensured that this function may be provided by a few and simple adaptations of already existing components, and problems of leaky gaskets are avoided. As a result, the cost price is kept at a level which is comparable with a standard welding torch. The function does not involve any considerable increase in weight or size either relative to known torches.

When, as stated in claim 2, the connecting element is configured as a cylindrical member comprising one or more segments of an external toothed rim, said segments extending around the cylindrical member over a portion of the circumference of the member, and each segment contains at least one tooth, a connecting element is achieved, which is adapted to operate in connection with a toothed rim on a handle and is capable of rotating inside the handle when the toothed rims or the segments are disengaged.

When, as stated in claim 3, the extent of the toothed rim corresponds to the circumference of the connecting element, a connecting member is achieved, which has a great degree of freedom.

When, as stated in claim 4, each of the shell parts of the handle is configured with one half of a toothed rim or with a segment of a toothed rim, and each segment contains at least one tooth, it is ensured that the shell parts will be capable of operating in connection with a toothed rim on a connecting element, and that it is possible to select the amount of adjustment be- tween the handle and the gooseneck freely. It is moreover advantageous, as stated in claims 5 and 6, to configure the toothed rims or segments of the toothed rims with a pitch corresponding to seven teeth on a circular sector of ninety degrees, and to configure the teeth such that they are at least three millimetres. It is ensured hereby that the need of adjustment is met.

When, as stated in claim 7, the locking mechanism comprises a union made of a flexible material and having inwardly facing bosses as well as outwardly facing frictional locks on the handle, which extend partly trans- versely and partly obliquely relative to the centre line of the handle, said locking bosses and said frictional locks being configured to engage each other, it is ensured that it is possible to maintain a selected position between the handle and the gooseneck with the union in a locked position, and to release the frictional locks with a smaller rotation of the union.

Finally, it is expedient, as stated in claim 8, that the toothed rims are kept in engagement with each other by a spring or a rubber ring, e.g. an O-ring, which is confined between the union and the connecting element.

It is moreover advantageous, as stated in claims 9 and 10, that the oblique extent of the frictional lock gives at least an axial displacement of the order of three millimetres with a partial rotation of the union, and that the rotation is at least 15 degrees.

When the welding torch is constructed as stated in each of claims 1 - 10, an adjustment of the position between the gooseneck and the handle may be performed and as stated in claim 11.

The drawing

Preferred exemplary embodiments will be described more fully below with reference to the drawing, in which

Fig. 1 shows the welding torch according to the invention in perspective,

Fig. 2 shows a section of a lateral view of the welding torch,

Fig. 3 shows an enlarged section of the locking mechanism of the welding torch,

Fig. 4 shows the connecting element with an external toothed rim in perspective,

Fig. 4a shows a view of a detail of the toothed rim on the connecting element,

Fig. 5 shows the front part of the handle with an internal toothed rim and with a portion of the locking mechanism, in perspective, and

Fig. 6 shows a view of the union in perspective.

Description of the exemplary embodiments

Exemplary embodiments shown in figs. 1 to 6 will be described below.

Fig. 1 shows a view of the welding torch 1 seen in perspective. The welding torch is shown with a handle 2, which is formed by an upper shell part 3 and a lower shell part 4. The gooseneck 6 extends from the front edge of the handle and is terminated by a nozzle arrangement 7. The rear edge of the handle is equipped with a rotatable member 8, which directs a welding hose (not shown) into the handle. A locking mechanism 11 , of which only the union 10 is visible in the figure, is mounted on the front edge of the handle. A control current switch 9 is arranged below the handle.

Welding torches of the type shown may be adapted for water cooling or air cooling.

The interior of the handle 2 is shown in fig. 2 and fig. 3. It will be seen there how the connecting element 5 is mounted, and that it is firmly connected with the gooseneck 6. The welding hose (not shown) is passed into the handle via the rotatable member 8, which is arranged rearwardly on the handle, to the connecting element 5 via a plurality of couplings provided for wire, gas, cooling air or cooling water.

The sectional view in fig. 3 shows the locking mechanism 11 with the union 10, the bearing 22 and the cavity 12. A spring or a rubber ring, e.g. an O- ring (not shown) is arranged in the cavity to absorb production tolerances, if any, between the parts in the locking mechanism. The spring or the rubber ring ensures that pressure will always be present between the union 10 and the connecting element 5, which will urge the connecting element 5 rear- wards inside the handle.

Fig. 4 shows a perspective view of the connecting element 5. It will be seen there how the connecting element is configured as a cylindrical member which is capable of rotating inside the handle. It will moreover be seen that, at one end, it is equipped with a toothed rim 13, 15 which extends around the cylindrical member in the entire extent of the circumference. However, the toothed rim may also be divided into a plurality of segments 15 having an arbitrary number of teeth.

The toothed rim 13 or the segment 15 is advantageously configured with a pitch D (see fig. 4a) which corresponds to seven teeth on a circular sector of ninety degrees. This ensures that there is a sufficient number of adjustment positions to satisfy all practical adjustment wishes.

The length of the teeth from top to bottom is selected such that the length is at least three millimetres, it being possible, however, to select another length.

Fig. 5 shows the structure of the front part of the handle 2 in perspective. The lower shell part 4 is shown here with one half of a toothed rim 14 or a segment of a toothed rim 16. The upper shell part 3 is likewise equipped with one half of a toothed rim 14 or a segment of a toothed rim 16. The teeth are made with a pitch D which corresponds to seven teeth on a circular sector of ninety degrees. This ensures that there is a sufficient number of adjustment positions to satisfy all practical adjustment wishes.

The teeth of both toothed rims 13, 14 are configured with uniform tooth profiles so as to fit exactly in each other. However, they may also be configured with a profile where the flanks of the teeth do not have exactly the same inclination, so that the teeth are wedged together just before a tooth top and a tooth base touch each other when the toothed rims are pressed together. This results in a firm coupling without play.

The toothed rim 14 or the toothed rim segment 16 is configured such that the teeth are directed forwardly toward the front edge 21 of the handle. The toothed rim 13 and the toothed rim segment 15 of the coupling element 5 is configured such that the teeth are directed rearwardly and away from the gooseneck 6. This ensures that it is possible to pull the coupling element and the handle out of engagement with each other, and that the coupling element may be rotated one or more positions.

For the engagement to be removed, it is necessary to release the locking mechanism 11 first.

The locking mechanism is composed of an outwardly facing frictional lock 19 on the shell parts 3, 4 of the handle. The frictional lock extends partly transversely and partly obliquely relative to the centre line of the handle. On the transverse part, the frictional lock is equipped with at least one rib 20 which locks the union in the operating position. The oblique part is terminated by a boss 23, which prevents the union from falling off. Both shell parts 3, 4 are equipped with an outwardly facing frictional lock 19.

Further, as shown in fig. 6, the locking mechanism comprises a union 10, which is equipped with inwardly facing locking bosses 18 configured so as to be capable of engaging the frictional lock 19 on the handle.

The union 10 is made of a flexible material, so that rotation of the union is allowed in that the union is deformed slightly when the bosses 18 are moved past the ribs 20 in the frictional lock 19.

When the union 10 is rotated, the locking mechanism 11 is opened, and the oblique extent of the frictional lock ensures that the union is displaced axi- ally at a small rotation, so as to make room for pulling the toothed rims out of engagement with each other. In an advantageous embodiment, the displacement assumes the value of at least three millimetres at a rotation of at least fifteen degrees, it being possible, however, to select other values such as e.g. five millimetres at a rotation of seventeen degrees.

Claims

PATENT CLAIMS

1. A welding torch (1), in particular for MIG/MAG welding machines, said welding torch being connected with a welding machine by a welding hose and comprising a handle (2) formed by two shell parts (3, 4), in which a connecting element (5) for wire, gas, cooling air or cooling water is arranged, and to which a gooseneck (6) equipped with a nozzle arrangement (7) is additionally connected, and wherein the handle moreover comprises a rotatable member (8) through which the welding hose is passed into the handle to the connecting element, as well as a control current switch (9), c h a r a c t e r i z e d in that each of the handle and the connecting element is equipped with a toothed rim (13, 14) or segments (15, 16) of a toothed rim configured to engage each other, and that the engagement is lockable by a locking mechanism (11) arranged on the handle.

2. A welding torch according to claim 1, c h a ra cte rize d in that the connecting element (5) is configured as a cylindrical member comprising one or more segments (15) of an external toothed rim (13), said segments extending around the cylindrical member over a portion of the circumfer- ence of the member, and that each segment contains at least one tooth (17).

3. A welding torch according to claim 1 or 2, ch a ra cte ri zed in that the extent of the toothed rim (13) corresponds to the circumference of the connecting element.

4. A welding torch according to claim 1, ch a racte rized in that each of the shell parts (3, 4) of the handle (2) is configured with one half of a toothed rim (14) or with a segment (16) of a toothed rim (14), and that each segment contains at least one tooth (17).

5. A welding torch according to any one of claims 1 -4, c h a ra ct e ri zed in that the toothed rims (13, 14) and the segments (15, 16) are configured with a pitch (D) corresponding to seven teeth on a circular sector of ninety degrees.

6. A welding torch according to any one of claims 1 -5, ch a ra cte rized in that the teeth (17) of the toothed rims are at least three millimetres deep.

7. A welding torch according to claim 1, c h a ra cte ri ze d in that the locking mechanism (11) comprises a union (10) made of a flexible material and having inwardly facing locking bosses (18) as well as outwardly facing frictional locks (19) on the handle, which extend partly transversely and partly obliquely relative to the centre line of the handle, said locking bosses and said frictional locks being configured to engage each other.

8. A welding torch according to claim 1 or 7, ch a ra cte ri zed in that the toothed rims (13, 14) are kept in engagement with each other by a spring or a rubber ring, which is confined in the cavity (12) between the bearing (22) and the connecting element (5).

9. A welding torch according to claim 7, ch a ra cte ri zed in that the oblique extent of the frictional locks give an axial displacement of the order of three millimetres at a partial rotation of the union.

10. A welding torch according to claim 9, ch a racte rized in that the rotation is at least fifteen degrees.

11. A method of adjusting the position of the gooseneck relative to the handle on a welding torch according to any one of the preceding claims, ch a ra cterized in that the union is rotated partly and displaced axially so that the locking mechanism is opened,

that the gooseneck is pulled forwards and out of engagement with the toothed rim in the handle,

that the gooseneck is rotated to a desired position,

that the gooseneck is pushed back into engagement with the toothed rim in the handle, and

that the union is rotated back to is starting position.