GB2025822A - An improved Device for Guiding Pairs of Rolled Members to be Connected by Welding - Google Patents

Abstract

A device capable of guiding simultaneously two pairs of metal members prior to welding, which comprises a pair of vertical axis outer tightening rollers suitable to tighten together a horizontal core member and either a single or two vertical members respectively, of a single or double T section to be produced by welding; between said pair of outer tightening rollers there being arranged a pair of vertical axis inner tightening rollers (21, 22), biased away from each other with forces which are opposed and equal to the tightening force of the respective outer roller; said pair of inner rollers being freely movable together in either direction transversally of the longitudinal direction of the sections. Preferably, the inner rollers are vertically adjustable, and may be swung away so that a single larger size core section may be held between the two outer rollers. <IMAGE>

Description

SPECIFICATION An Improved Device for Guiding Pairs of Rolled Sections to be Connected by Welding The present invention relates to an improved device for guiding and supporting pairs of sections to be connected by welding.

It is known that beyond certain sizes, steel sections used in civil and naval constructions are not manufactured as rolled sections, but as sections connected by welding.

Recently, this method has been extended also to the range of smaller size sections, giving rise to a problem of adjusting the multiple head welding lines to cope with the smaller size sections.

In general, the welding lines for connected sections, usually to form T or double-T bars, require that the section core is fed by means of a vertical axis roller system and that two flat bands are fed, also by a roller system, continuously through a welding station.

At the welding station, a suitable number of welding heads effect simultaneously two opposed angle welds if a single flat band is provided (T sections) or four angle weldings, opposed two by two, when two flat bands are provided (double-T sections).

Near said welding station, the known devices usually comprise two vertical axis rollers with their vertical axes arranged outside the section, one of said rollers being stationary, while the other is movable perpendicular to the longitudinal axis of the section in order to adjust within suitable limits, for sections of different heights.

The roller traversal relative to the longitudinal axis of the connected section is directed, usually by a hydraulic cylinder, towards the other vertical axis outer roller, so as to keep adherent the core section and the flatband or flatbands during the welding operation.

Said tightening force on the sections is required because the section core is not cut straight; in thie way, deformation due to welding shrinkage is compensated by the initial deformation of the core.

The necessity of tightening together the core and flat-band during the welding operation, must be considered when instead of one section at a time, two sets of sections are to be fed to the welding line, e.g. to form two T bars of such a size as to be positioned with cores on the same plane in the welding device (see for example Figs 12 to 14).

In such a case according to the known art, the two cores of the two bars to be welded simultaneously are fastened by clamps, which at the end of the welding operation are loosened and brought back to the start of the line for reuse.

This procedure is expensive in both workmanship and material, as said clamps had to be replaced after a given number of uses.

An object of some embodiments of the present invention is to remove this inconvenience in a very simple manner, avoiding any requirement that the elements of the invention may require to be removed as soon as the device is to be used again for welding single large size bars.

The present invention provides a device for guiding sections to be connected by welding, which comprises a pair of vertical axis outer tightening rollers suitable to tighten together a horizontal core section and vertical flatband section or sections of a bar to be produced by welding; between said pair of outer tightening rollers there being arranged a pair of vertical axis inner tightening rollers, biased away from each other with forces which are opposed and equal to the tightening force of the respective outer roller; said pair of inner rollers, being freely movable in either direction transversally of the longitudinal direction of the sections.

The pair of inner rollers may be tilted downwards, so as to be removed out of the area passed through by cores of larger size sections being welded one by one.

Said pair of inner rollers may be adjustable vertically so as to match to the various shapes of sections to be connected.

Embodiments of the invention will be described with reference to the accompanying drawings: wherein Figure 1 is a diagrammatic cross-section of a prior art welding device; Figure 2 is a section similar to the one of Fig. 1, with the difference that the section is a T-section and not a double-T section as shown in Fig. 1; Figures 3 and 4 are a top and cross-section view of a pair of sheet strips adjacent but not yet welded, cut straight; Figures 5 and 6 are views similar to those of Figs. 3 and 4, showing the section after the welding; Figures 7 and 9 to 11 (there is no Figure 8) are similar to Figs 3 to 6 but relating to the case when the sheet strips are not cut straight so as to compensate the deformation effect caused by shrinkage; Figure 12, similar to Figs. 1 and 2, shows the welding device when two composed T sections are to be welded simultaneously;; Figure 13 is similar to Fig. 12 but shows a device according to the invention; Figure 14 is similar to Fig. 13, though relating to the case when the sections to be welded are doubleT sections; Figure 15 is a top view showing the starting position of the sheet the two composed sections shown in Fig. 13 consist of; Figure 16 is a top view showing the same sections after welding together; Figure 17 is a diagrammatic top view of the device according to the invention in operation on a pair of sections to be welded of the type shown in Figs, 15 and 16; Figure 18 shows a control apparatus for controlling the displacement of the inner rollers of the device according to the invention; Figure 19 shows along a transverse plane the welding device according to the invention with particular reference to the guide and control elements for the inner rollers;; Figure 20 is a view similar to the one of Fig.

19, along a vertical plane perpendicular to the previous one.

Obviously, Figs. 18, 19, 20 refer to nonlimiting constructive solutions of the invention With particular reference to Figs. 1 to 7 and 9 to 1 there are known welding device for c connecting sheet strips so as to obtain sections or bars by welding.

Such obtained bars may be double-T bars, as those shown in Fig. 1, or T bars, as those shown in Fig. 2, which are particularly suitable for naval use, as in this case the second flat-band of the bar will be represented by a ship's plating.

Known multiple head welding devices are usually provided with a pair of pressure rollers, or stop rollers, whose vertical axis is arranged outside the section to be connected. Such outer rollers are denoted by numerals 1 and 2. The section usually comprises a core 3 and one or two flatbands 4 and 5. Core 3 is supported and guided by two pairs of horizontal axis rollers 6 and 7, while said flatbands 4 and 5 are supported and guided in known manner by other pairs of rollers, not shown in the drawings, acting on their side edges.

The whole constituted by the sheet strips representing the core and the flatband or flatbands of the section connected by welding are kept in contact to each other during the welding operation, by the roller pairs 1 and 2 which push towards each other the sheet strips to be welded.

The need for such a force to keep in contact the various sheet strips the final section consists of is shown in Figs 3 to 7 and 9 to 11.

The sheet strips 3 and 4-intended to form the core and the flatband respectively of a T section, in this case with a symmetric flatband-cannot be cut with straight sides, as shown in Fig. 3, as in this case after welding the bar prouced would have a curve of the kind shown in Fig. 5 due to the known phenomena of shrinking.

To this end, it is known to cut the sheet 3 intended to form the section core with a suitable curve, as shown in Fig. 7 in such a way that the shrinking phenomenum will straighten up the sheet strip constituting the core in the way shown in Fig. 10.

However, when sheet strips shaped as shown in Fig. 7 are to be welded, it is obvious that during welding said flatband 4 and core 3 are to be pressed against each other, and rollers 1 and 2 are provided for this purpose. In Fig. 1 arrows 10 show diagrammatically the electrodes of said welding heads.

When instead of a single bar formed by a core 3 and one or two flatbands 4 and 5, the device has to weld simultaneously two bars, the relevant cores 103,203 (Fig. 12) are made integral to each other, so that the tightening force of the two rollers 1 and 2 may be transmitted from one bar to the other.

In known way, it is usual to make integral the cores 103, 203 of two bars mounted simultaneously on the welding device by the use of clamps which, as already said, have to be continuously removed from pairs of already welded bars and transferred to the other end of the device with a considerable loss of time.

As shown in Figures 13 and 14, instead of making integral the cores 103,203 of the pairs of bars to be welded simultaneously in the same apparatus, two additional inner stop rollers are arranged between said cores 103,203 together with a pair of welded cross bars 81,82 (Figures 15 and 16) which are then removed by cutting the bar ends along lines 83, 84.

Obviously said rollers 21,22 are pushed outwards with a force F equal to the force F exerted by said outer stop roller 2, balanced by an equal reaction force exerted by said roller 1.

Usually roller 1 is stationary, while roller 2 is movable transversally to the longitudinal axis of the bars to be welded by means of a hydraulic jack developing said force F.

Fig.13 also shows diagrammatically a hydraulic apparatus able to generate, through jacks 2' 1, 23, 24 whose pistons are operative on the rotation axes of rollers 2, 21, 22, forces F which are equal in absolute value by means of a single pump F. Said hydraulic apparatus is actually more complex than before but may be easily realised by any technician in the art.

The present invention provides not only said rollers 21, 22 but also their support and adjustment device allowing, as shown in details in Figs. 18 and 20, to bring said rollers 21, 22 to the working position or to the rest one and to adjust their vertical position as a function of the kind of sections to be produced.

According to the preferred embodiment shown in Figs. 1 9, 20 each of the intermediate stop rollers 21,22 is mounted on a corresponding slide 23', 24' mounted on a support 30.

The two hydraulic cylinders 23, 24 whose piston rods 25, 26 are rigidly connected to flanges 27, 28 projecting below said slides 23', 24', are positioned inside the support 30. In such a way, the motion of pistons 25', 26', is transmitted to slides 23', 24' through the piston rods 25, 26 and said flanges 27, 28.

In order to accompany the motion of slides 23', 24' in a correct way, said flanges 27, 28 have associated guide bars 31,32 fastened on one side to the respective flanges 27, 28 and freely slidable on the other side in calibrated holes of said support 30.

Said pistons 25', 26' are actuated in any suitable way by a hydraulic pressure controlled in such a way that the force exerted by the intermediate stopollers 21,22 is equal to the one exerted by the outer rollers 1, 2.

As said pistons 25', 26' may freely move inside the respective cylinders under the action of the hydraulic pressure, it is necessary that the displacement of said two pistons may be made symmetric with respect to a symmetry plane denoted by (A) in Fig. 19.

To this end a mechanical device controlling the displacement of pistons 25', 26' or slides 23', 24' may be provided.

Figure 18 shows two racks 41,42 associated stationarily to said two slides 23', 24' engaging a single idle toothed wheel 43, whereby movement in either direction of said two slides will always have an opposite sign and equal absolute value.

However a chain device not shown may be useful as well.

Said support 30, shown in Fig. 19, is movable vertically being mounted on a bracket 33 (Fig. 20) in order to position said intermediate rollers 21, 22 exactly corresponding to the inner edges of the cores 103, 203 of said two sections to be welded.

To this end, bracket 33 is articulated to the upper end of a hydraulic jack 34 which is fastened in articulated manner at its lower end to the base of a frame 50.

In order to accompany in a suitable manner the upwards or downwards motion of said bracket 33 and support 30, the former is provided with two pairs of guise wheels, with opposed horizontal axes, moving on two vertical guides 36 fastened on said frame 50.

Said wheels are grooved and thus prevent bracket 33 from tilting either around an axis perpendicular to the drawing plane of Fig. 19, or around an axis perpendicular to the drawing plane of Fig. 20.

Frame 50 is in the form of an inverted U with the open end directed downwards; that is it is formed by a vertical plane 51 on whose outer face said guides 36 are mounted, and on whose outer lower end is mounted in articulated manner the lower end of said jack 34. Further, said frame 50 comprises an upper cross bar 52 and a second vertical element 53.

The lower end of said element 53 is fastened in articulated manner at 54 on a slide 60. A pin 55 connects said frame 50 to the slide 60, preventing it from tilting to the direction shown by a dotted line in Fig. 19.

Said slide 60 is freely movable on two guides 61,62 perpendicular to the longitudinal direction of the bars 103,203 to be welded. Guide 61 comprises a longitudinal groove in form of an upward open V receiving slidably two wheels 63 bearing the weight of said slide 60. Guide 61 rests in turn on a suitable bearing structure 70 of said frame. Guide 62 of said slide 60 consists of a tubular profile parallel to said guide 61 and arranged above the latter.

a pair of vertical axis opposed wheels 64, 65 slide freely on said tubular profile, and at least a third wheel 66 bearing on the lower face of said tubular profile slides on the same lower face.

In this way, guide 61 bears the weight of slide 60, while guide 62 by pair of wheels 64, 65 prevents said slide from tilting around an axis perpendicular to the drawing plane of Fig, 20.

Wheel 66 avoids any undesired lifting of slide 60 from guide 61. In these circumstances, it is obvious that piston 34 allows the intermediate stop rollers 21, 22 to be positioned exactly at the level of the inner edge of cores 103, 203 of the pair of bars to be welded.

Rollers 21, 22 may freely approach each other (upto the minimum position denoted by 21 22') and move away from each other under control of pistons 25' 26'. in the respective cylinders 23, 24 is maintained, in a manner known per se, such a pressure that the outward directed force exerted by rollers 21. 22 is exactly equal to the inward directed force exerted by rollers 1,2.

Further, thanks to said slide 60, the whole comprising the intermediate stop rollers 21,22 may move together in either direction.

Pin 55 functions to allow the whole consisting of rollers 21, 22, support 30 and frame 50 to tilt to the position shown by a dotted line in Fig. 20.

In such a position, said whole is below the plane of said core 3 to allow a section of such width as to occupy the entire width of the device to be welded, as shown in Figs, 1 and 2.

Therefore, it is possible to change quickly from the welding of a single section to the welding of a pair of sections.

It is to be appreciated that correct positioning of said frame 50 in its operating position is obtained by means of a stop tooth 70 resting on the edge of said slide 60.

Obviously, the movement of said bracket 33 and said slide 60 might be obtained in an alternative manner with respect to that shown in detail in Figs. 19 and 20.

Claims (12)

Claims

1. A device for guiding sections to be connected by welding, which comprises a pair of vertical axis outer tightening rollers suitable to tighten together a horizontal core section and vertical flatband section or sections of a bar to be produced by welding; between said pair of outer tightening rollers there being arranged a pair of vertical axis inner tightening rollers, biased away from each other with forces which are opposed and equal to the tightening force of the respective outer roller; said pair of inner rollers being freely movable in either direction transversally of the longitudinal direction of the sections.

2. A device as claimed in claim 1, wherein said vertical axis inner rollers are mounted on a pair of slides movable transversally to the longitudinal direction of the sections, each of said slides being connected to the piston axis of a hydraulic cylinder biased outwards by a force equal to the tightening force of said two outer tightening rollers.

3. A device as claimed in claim 2, wherein said slides are mounted on a support which carries the cylinders actuating said slides, said support being movable vertically under control with respect to a base frame, so as to allow adjustment of the vertical height of said inner rollers.

4. A device as claimed in claim 3, further comprising means for keeping equidistant the two inner rollers from the intermediate line of the support; said means consisting of a gear means.

5. A device as claimed in claim 3 or 4, wherein vertical displacement of said support with respect to the frame is achieved by means of a hydraulic cylinder.

6. A device as claimed in claim 5, wherein said frame comprises a pair of vertical guide rails engaged by stop wheels mounted on said support to allow relative motion between the support and the frame.

7. A device as claimed in claim 6, wherein said frame has substantially the form of an inverted U whose branches respectively constitute a first vertical upright, a second upright parallel to the first and an upper cross bar connecting said uprights; the guide rails for the relative displacement between frame and support being arranged on the outer face of said first upright; and wherein said frame may tilt around an articulation pin provided at the base of said second upright, until the whole of said frame and support is below the laying plane of core sections to be welded so as to allow a single core to be disposed between the outer rollers.

8. A device as claimed in claim 7, wherein in order to connect the frame in its operating position with the two vertical uprights, at least one locking pin for locking the frame in its operating position is provided.

9. A device as claimed in claim 7 or 8, wherein said frame is supported, is said articulated manner by a slide movable transversally of the longitudinal direction of the sections to be welded.

10. A device as claimed in any of claims 3 to 9, wherein said frame is movable on a pair of superposed guides-the lower of which comprises a longitudinal groove to receive a pair of aligned wheels, while the second offers a sliding surface to a pair of vertical axis wheels mounted on said frame so as to bear against the two opposite sides of said second guide; and wherein said frame carries a horizontal axis wheel rolling on the downward directed surface of said second guide.

11. A device as claimed in claim 10, wherein stop means are provided between said frame and the guids supporting it, in order to define operating and resting positions.

12. A device for guiding sections to be connected by welding substantially as described with reference to and as shown in any of Figures 13,14and 17to20.