GB1562462A - Flame cutting machine - Google Patents

Description

(54) FLAME CUTTING MACHINE (71) We, MESSER GRIESHEIM GmbH, a Company organised under the laws of the Federal Republic of Germany, of Hanauer Landstrasse 330, D-6000 Frankfurt/M, Federal Republic of Germany, do hereby the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a flame cutting machine having at least one multi-torch unit, some of the torches of which are adjustable relative to one another and relative to the workpiece to be cut.

Multi-torch units of the above-mentioned type have been known in the art for a long time; see, for example, United States Patent Specification No. 2665 900 and British Patent Specification No. 887 193.

Flame cutting machines equipped with these known multi-torch units are employed, for example, in the trimming of workpiece edges (sheets, panels) to prepare such edges preliminary to welding. These multi-torch units are particularly suitable for the preparation of the edges of flat workpieces, such as sheets, which are to be welded together.

It often happens, however, especially in the shipbuilding industry, that shaped workpieces have to be trimmed, for example Lbeams and T-beams, the beams having to be cut off to a certain length with simultaneous production of welding edges. Owing to the geometry of such workpieces it is necessary to start the cut at the web and direct it towards the flange. Now, when the first square cut has been made in this way (the square cut of the flange, running vertically, is made with a second multi-torch unit), the flame cutting machine or the workpiece being dealt with is conveyed into the new cutting position. However, to permit the making of symmetrical square cuts on such a workpiece (K-, Y-cuts) it is necessary, with known multi-torch units, to adjust the outer bevel torches afresh so that a symmetrical cut can be obtained as a result.

This angular adjustment is time-consuming and has to be carried out precisely again and again as otherwise there would be no symmetry between the two welding edges of the workpiece.

The problem of the present invention is to design the multi-torch unit in such a way that it can be used especially for trimming or cutting shaped workpieces and that the trimming operation (welding edges preparation) can be carried out rapidly, and without troublesome readjustment of the bevel torches, on the ends of the workpieces.

According to the present invention, there is provided a flame cutting machine having at least one multi-torch unit, some of the torches of which are adjustable relative to one another and relative to the workpiece to be cut, characterized in that the multitorch unit has five torches, a centre one of which is held in a stationary cutting position on the unit, whilst one pair of the remaining four torches is movable, alternately with the other pair of said four torches between a cutting position and a position of rest.

This arrangement of the torches on the multi-torch unit according to the invention, has the advantage that the first welding edge is produced by the one pair of torches that is in the cutting position, the second welding edge being produced by the second pair of torches which has been swung from its inoperative position into the cutting position, thereby at the same time swinging the first pair of torches back into its inoperative position, in accordance with a predetermined adjustment or setting of the cutting torches.

In one embodiment of the invention there is provided a swivel device comprising swivel links mounted on a shaft and having lever arms pivotally connected at one end to the ends of the swivel links, and at their other ends to the torches in such a way that the torches positioned respectively at the front or rear of a bracket or support on the torch unit can be swung in opposite directions by the swivel device. From this it follows that, in each case, the torches disposed diametrically opposite one another on the front and rear of the bracket or support can be swung in the same direction. Hence, be sides the stationary central torch, which remains continuously ignited, there is always one front and one rear bevel torch in the cutting position (or inoperative position) simultaneously and', depending on torch combinations, the trimming is effected along the left side and then along the right side of the workpiece, so that symmetrical welding edges result, as will be explained later in greater detail.

The invention provides further for an arm to be disposed on the shaft carrying the swivel links and a spring to act on the arm.

This spring ensures retention of the torch position selected at any given time i.e. the respective end positions of the swivel device.

Since, as has been mentioned already, there are always only two of the four bevel torches in the cutting position, the other two being in the inoperative position, it is advantageous if the supply of media i.e. gas etc. is also correspondingly controlled, that is to say the media is cut off to the "inoperative" torches and switched on for the "operative" torches. For this purpose it is proposed that a cam be provided to actuate a control valve for the media which is disposed on the bracket or support.

Further advantages of the invention will become apparent from the following description of the invention which is illustrated by way of example in the accompanying drawing in which: Figure 1 is a schematic view of a flame cutting machine; Figure 2 is a front elevation, on an enlarged scale, of a multi-torch unit according to the invention; Figure 3 is a side elevation as seen from the left of Figure 2; Figures 4 and 5 are schematic views of the two end position of the torch mountings, and Figure 6 shows the arrangement of the torches for the production of symmetrical welding edges.

Referring to the drawings, Figure 1 shows a flame cutting machine having two side parts 12 which are interconnected by a transverse track 14. Provided below the transverse track is a worktable 16 (roller conveyor) for a workpiece 18, for example an L-section, which is to be treated.

A multi-torch unit 20 is positioned on the transverse track 14 so as to be movable transversely, the unit also being provided for heightwise adjustment. At its lower end facing the workpiece the multi-torch unit 20 carries a plurality of cutting torches 22, the arrangement and manner of fixing on the torch unit will be described hereinafter.

It is obvious that instead of one single multi-torch unit it is also possible to provide two and more such units on the flame cutting machine.

In Figures 2 and 3 the multi-torch unit 20 according to the invention is shown on a larger scale.

At the lower end of a mounting support 24 for the multi-torch unit 20, two axles 26 are positioned in such a way that they project both at the front side 28 and also at the rear 30 of the support 24. Two adjusting devices 32, 34 and 36, 38 are hingedly mounted on the respective free ends of the axles. Each adjusting device has a frame 40 with a threaded spindle 42 extending axially therethrough. Rotation of the threaded spindle by means of a knob 44 effects movement of a vertical holder 46 carried by the threaded spindle. Each vertical holder 46 is in the form of a sliding head by means of which, again through knobs 48, one adjustable bevel cutting torch 22 (b-e) can be moved vertically relative to the horizontal adjusting device 32.

This permits adjustment of the torches in two planes.

Provided at the bottom end of the vertical holder 46 is a pin 50 about which a cutting bevel torch 22 (b-e) can be swung and thereafter fixed at a selected cutting angle by means of a clamping ring 52.

A further torch 22 is fixed centrally and stationarily to the mounting support 24 and on the vertical axis thereof. This central torch is always used with two of the bevel cutting torches 22 (b-e).

Angular adjustment of the bevel cutting torches 22 (b-c) or 22 (d-e) to obtain the required shape of the welding edge is effected by way of the adjusting devices 3238 (=horizontal adjustment), by way of the vertical holder 46 (adjustment for height), and by way of the clamp connection 50, 52 by which the setting of the cutting angle is carried out.

As can be seen from Figures 2 and 3, there is also a shaft 54 hingedly mounted at the top end of the mounting support 24.

Fxed to one of the shaft ends projecting from the front side 28 are a swivel link 56 and a lever 58.

Disposed on the other end of the shaft 54 associated with the rear 30 are a further swivel link 60 and also an arm 62. Pivotally connected to each of the two swivel links 56, 60 are two lever arms 64, 66 and 68, 70 respectively. Each of the four lever arms is connected to one of the adjusting devices as shown in the following table.

SWIVEL LINK 56: Lever arm 64 is connected with adjusting device 32 (torch 22b).

Lever arm 66 is connected with adjusting device 34 (torch 22e).

SWIVEL LINK 60: Lever arm 68 is connected with adjusting device 36 (torch 22d).

Lever arm 70 with adjusting device 38 (torch 22c).

From this association of lever arms and adjusting devices it will be understood that a "front" and a "rear" bevel cutting torch 22 always co-act with one another. As shown in Figure 2, these are the torch 22b (front left) and the torch 22c (rear right).

which are in a cutting position with the fixed central torch 22o The two remaining torches 22d and 22e are in their retracted or inoperative positions (the adjusting devices 36 and 34 being swung upwards).

One end of a tension spring 72 is attached to the arm 62 (see Figure 3), its other end being attached to a bracket 74 fixed to the mounting support 24. The purpose of this spring is to establish the two end positions of the swivel links 56, 60.

In this connection, reference is made to Figures 4 and 5 which show the two positions of the spring in a simplified manner.

As the lever 58 swings in the direction of the arrow, the lower attachment of the spring passes through under the central axis of the shaft 54 into the end position shown in Figure 5. In this position (and also in the spring position shown in Figure 4) a swinging force is exerted by the spring on the arm 62 which is effective in the direction of the arm 66. The swivel links 56, 60 are maintained by this spring force in their respective end positions shown in Figures 4 and 5 with the result that the torches 22b', c or 22d, e remain fixed in their adjusted positions.

Referring to Figures 4 to 6 the trimming (preparation of a welding seam) of workpieces 18 (an L-beam in Figure 4 and a Tbeam in Figure 5) by means of the multitorch unit 20 of this invention will now be described. As already mentioned, initially, it is essential that the welding edges to be produced (for example a K-cut) are sym- metrical with one another at both ends of the workpiece 18 (Figure 6). The welding edge which is on the right in Figure 6 is cut with the position of the swivel system 54- 74 as shown in Figure 4. In the torch adjustment provided for this cutting operation the central torch 22eft and also the left front torch 22b and the rear torch 22c are in the cutting positions.

The left rear torch 22d and the right front torch 22e are in the retracted or inoperative positions.

After the horizontally disposed web of the workpiece 18 has been cut through and simultaneously trimmed in the direction of the arrow "S" close to the vertical part 18a of the workpiece, the same process being applied to this part with a second multitorch unit (not shown), the unit 20 travels back into its starting position at the start of the web (in Figures 4 and 5 out of the plane of the drawing, that is to say in the opposite direction to the arrow "S"), while at the same time the flame cutting machine or the workpiece 18 is brought into the new cutting position.

Since a symmetrical welding edge (see the left hand side of Figure 6) is provided at the other end of the workpiece 18, the lever 58 is swung into its left end position (Figure 5).

Then the rear left torch 22d and the front right torch 22e (with the central torch 22a) come into the cutting position, while the torch 22h and the torch 22c are retracted into the inoperative position.

Then, with this cutting position of the multi-torch unit (torches 22a, 22d and 22e), a symmetrical welding edge is produced at the other end of the workpiece 18 (Figure 5 and Figure 6, left).

By means of the multi-torch unit according to the invention it is possible, advantageously, by rapid swivelling of the torch pairs 22b, 22c, or 22d, 22e, to move these quickly, and without additional adjustment of the torches, into the cutting or inoperative position, respectively, by way of the swivel system 54-74. The torches have to be adjusted only once in the required cutting angle and they continue to retain this angular setting irrespective of their position (inoperative or cutting position).

It is obvious, and still within the scope of the invention, that instead of effecting manual adjustment of the torches 22 (b-e) the swivel system may also operate hydaulically and/or pneumatically.

Since there are alternately always only two bevel torches 22b, 22c, or 22d, 22e in action together with the central torch 22a, it is advantageous to control the supply of gases and/or cooling water to the torches 22b22e in such a way that, at any given time, only those torches in the cutting position are supplied with the media. To this endas can be seen from Figure 3-there is a cam 76 fixed on the shaft 54 which cooperates with a switch 78 disposed on the mounting support 24. Depending on the turning motion of the shaft 54, the supply of media is opened up by the switch 78 for one pair of torches, for example 22b. 22c and simultaneously cut off from the other paid (22d, 22e) and vice versa. The pair of torches which is swung into its cutting position at any given time thereby ignites from the flame of the central torch 22a which may burn continuously.

WHAT WE CLAIM IS:- 1. A flame cutting machine having at least one multi-torch unit, some of the torches of which are adjustable relative to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. SWIVEL LINK 60: Lever arm 68 is connected with adjusting device 36 (torch 22d). Lever arm 70 with adjusting device 38 (torch 22c). From this association of lever arms and adjusting devices it will be understood that a "front" and a "rear" bevel cutting torch 22 always co-act with one another. As shown in Figure 2, these are the torch 22b (front left) and the torch 22c (rear right). which are in a cutting position with the fixed central torch 22o The two remaining torches 22d and 22e are in their retracted or inoperative positions (the adjusting devices 36 and 34 being swung upwards). One end of a tension spring 72 is attached to the arm 62 (see Figure 3), its other end being attached to a bracket 74 fixed to the mounting support 24. The purpose of this spring is to establish the two end positions of the swivel links 56, 60. In this connection, reference is made to Figures 4 and 5 which show the two positions of the spring in a simplified manner. As the lever 58 swings in the direction of the arrow, the lower attachment of the spring passes through under the central axis of the shaft 54 into the end position shown in Figure 5. In this position (and also in the spring position shown in Figure 4) a swinging force is exerted by the spring on the arm 62 which is effective in the direction of the arm 66. The swivel links 56, 60 are maintained by this spring force in their respective end positions shown in Figures 4 and 5 with the result that the torches 22b', c or 22d, e remain fixed in their adjusted positions. Referring to Figures 4 to 6 the trimming (preparation of a welding seam) of workpieces 18 (an L-beam in Figure 4 and a Tbeam in Figure 5) by means of the multitorch unit 20 of this invention will now be described. As already mentioned, initially, it is essential that the welding edges to be produced (for example a K-cut) are sym- metrical with one another at both ends of the workpiece 18 (Figure 6). The welding edge which is on the right in Figure 6 is cut with the position of the swivel system 54- 74 as shown in Figure 4. In the torch adjustment provided for this cutting operation the central torch 22eft and also the left front torch 22b and the rear torch 22c are in the cutting positions. The left rear torch 22d and the right front torch 22e are in the retracted or inoperative positions. After the horizontally disposed web of the workpiece 18 has been cut through and simultaneously trimmed in the direction of the arrow "S" close to the vertical part 18a of the workpiece, the same process being applied to this part with a second multitorch unit (not shown), the unit 20 travels back into its starting position at the start of the web (in Figures 4 and 5 out of the plane of the drawing, that is to say in the opposite direction to the arrow "S"), while at the same time the flame cutting machine or the workpiece 18 is brought into the new cutting position. Since a symmetrical welding edge (see the left hand side of Figure 6) is provided at the other end of the workpiece 18, the lever 58 is swung into its left end position (Figure 5). Then the rear left torch 22d and the front right torch 22e (with the central torch 22a) come into the cutting position, while the torch 22h and the torch 22c are retracted into the inoperative position. Then, with this cutting position of the multi-torch unit (torches 22a, 22d and 22e), a symmetrical welding edge is produced at the other end of the workpiece 18 (Figure 5 and Figure 6, left). By means of the multi-torch unit according to the invention it is possible, advantageously, by rapid swivelling of the torch pairs 22b, 22c, or 22d, 22e, to move these quickly, and without additional adjustment of the torches, into the cutting or inoperative position, respectively, by way of the swivel system 54-74. The torches have to be adjusted only once in the required cutting angle and they continue to retain this angular setting irrespective of their position (inoperative or cutting position). It is obvious, and still within the scope of the invention, that instead of effecting manual adjustment of the torches 22 (b-e) the swivel system may also operate hydaulically and/or pneumatically. Since there are alternately always only two bevel torches 22b, 22c, or 22d, 22e in action together with the central torch 22a, it is advantageous to control the supply of gases and/or cooling water to the torches 22b22e in such a way that, at any given time, only those torches in the cutting position are supplied with the media. To this endas can be seen from Figure 3-there is a cam 76 fixed on the shaft 54 which cooperates with a switch 78 disposed on the mounting support 24. Depending on the turning motion of the shaft 54, the supply of media is opened up by the switch 78 for one pair of torches, for example 22b. 22c and simultaneously cut off from the other paid (22d, 22e) and vice versa. The pair of torches which is swung into its cutting position at any given time thereby ignites from the flame of the central torch 22a which may burn continuously. WHAT WE CLAIM IS:-

1. A flame cutting machine having at least one multi-torch unit, some of the torches of which are adjustable relative to

one another and relative to the workpiece to be cut, characterized in that the multitorch unit has five torches, a central one of which is held in a stationary cutting position on the unit, whilst one pair of the remaining four torches is movable, alternately with the other pair of said four torches, between a cutting position and a position of rest.

2. A machine according to claim 1, wherein the movable torches are connected to adjusting devices which are angularly turnable about a common shaft mounted in a bracket or support on the torch unit.

3. A machine according to claim 2, wherein two of the movable torches are located on the front side of said bracket or support and two on a rear side of said bracket or support.

4. A machine according to claim 3 wherein a swivel device is provided on said bracket or support for facilitating angular displacement of the movable torches.

5. A machine according to claim 4, wherein the swivel device comprises annular collars carried by a shaft, and lever arms being pivotally connected at one end to the collars and at their other ends to the adjusting devices for the torches.

6. A machine according to claim 4 or claim 5, wherein the torches located respectively at the front and the rear of the bracket or support are capable of being swung in opposite directions by the swivel device.

7. A machine according to claim 4 or claim 5, wherein the torches located diametrically opposite one another on the front and the rear of the bracket or support, are capable of being swung in the same direction.

8. A machine according to any one of the claims 4 to 8, wherein the swivel device is actuated manually by way of a lever.

9. A machine according to any one of claims 5 to 8, wherein there is disposed on the shaft carrying the swivel collars an arm to which a spring is connected.

10. A machine according to any one of the claims 5 to 9, wherein a cam is provided on the shaft carrying the swivel collars, said cam actuating a control valve disposed on said bracket or support for controlling the supply of gas or other fuel to the torches, and by means of which the gas or other fuel is fed alternately to each pair of torches.

11. A flame cutting machine, substantially as hereinbefore described with reference td, or as shown in, the accompanying drawings.