CA2358279A1 - High speed welding apparatus with interchangeable weld fixture capability - Google Patents

Abstract

An apparatus for welding two or more sets of workpieces including a welding station, a conveying transport apparatus to move individual sets of workpieces from a supply position to the welding station, and a component transport apparatus to convey the welded blank to an off feed position. The welding station includes a welding assembly, and at least one workpiece support fixture used to support the sets of parts in a desired position for welding. The workpiece support fixture includes a clamping assembly to releasably secure the set of workpieces and a modular base which permits the simplified removal and/or insertion of each support fixture into the welding station. The welding assembly includes a laterally movable weld head base to which the weld head is mounted, and a weld head support which enables the weld head to be moved in at least one direction substantially over all of the workpieces retained by the workpiece support fixture. The welding assembly may thus be used to weld together a set of workpieces retained in either of the support fixtures in the production of component blanks.

Description

HIGH SPEED WELDING APPARATUS WITH INTERCHANGEABLE
WELD FIXTURE CAPABILITY
SCOPE OF THE INVENTION
The present invention relates to a welding apparatus adapted for the high speed welding of component workpieces to form a component or blank, and more particularly a high speed welding apparatus which is configured for the concurrent manufacture of two or more component blanks, and which further may be rapidly and easily reconfigured to weld together component workpieces having different configurations.
BACKGROUND OF THE INVENTION
Current manufacturing systems used in the production of components such as tailored blanks typically include a laser, plasma or other welding fixture which is used to weld together two, three or more individual workpieces or parts along abutting weld seams.
For example, in the manufacture of vehicle and aircraft bodies, tailored component blanks used to make door and body panels are formed by butt welding together a number of sheet metal workpieces of different thicknesses. Following welding, the blanks may be oiled or dimpled, and the tailored blanks are thereafter press molded and trimmed to remove any waste stock, providing the finished part.
To reduce manufacturing time and achieve increased manufacturing efficiencies, various welding apparatus have been proposed for the automated qualification and welding together of the individual component workpieces. For example, commonly owned United States Patent No.
6,011,240 to Bishop et al, which issued on January 4, 2000, describes a production line for the automated manufacture of component blanks, in which the component parts or workpieces are moved longitudinally through a welding station by means of elongated magnetic conveyors.
Conventional automated welding apparatus, however, suffer a disadvantage in that the speed of blank manufacture is reduced as a result of increased times needed to sequentially convey the sheet workpieces to be joined to the welding station, to qualify and clamp the workpieces in the desired welding orientation, to then weld the workpieces along weld seams to form the component blank, and thereafter convey the finished component blank to an off loading site.
Conventional welding apparatus further suffer the disadvantage in that the reconfiguration of the assembly line to produce different component blanks is typically time consuming, and may require the welding apparatus to be shut down for several hours or even days. For example, in the production of tailored blanks used in automobile manufacture, it is the industry practice to first manufacture a production run consisting solely of left or right side vehicle parts, and thereafter produce only parts for the other opposite vehicle side. To enable the production of the corresponding right or left side part or, for that matter to produce a completely different component blank, necessitates that the manufacturing line be shut down, the clamping fixtures for the sheet workpieces be reconfigured to best support the new parts, and the weld head fixture movement reprogrammed.
A further disadvantage with conventional manufacturing systems exists in that they are typically of a large physical size, often extending thirty metres or more in length, requiring extensive production facilities.
SUMMARY OF THE INVENTION
To at least partially overcome some of the difficulties of prior art automated welding apparatus, the present invention provides for a high speed welding apparatus which may be used to concurrently manufacture two, three or more component blanks. The present system operates to position, align and clamp into place one set of component workpieces to be joined, while another set of component workpieces is welded together along adjacent edge portions, and the completed blank is conveyed to an off feed site for further processing.
Another object of the invention is to provide an apparatus for the production of vehicle, locomotive, ship, boat, railcar and/or aircraft parts, and which may be rapidly and easily reconfigured to produce different types of parts with minimal disruption and loss in production time.
Another object of the invention is to provide an apparatus used to concurrently manufacture two, three or more tailored blanks for use in vehicle or aircraft manufacturing, and which is configured to perform the positioning of sets of workpiece sheets to be joined in a welding station substantially simultaneously with the off loading of a completed blank therefrom.
Another object of the invention is to provide an automated component assembly line useful for the efficient welding of steel, aluminum or other metal sheets of equal or different thicknesses, to form tailored blanks.
A further object of the invention is to provide a welding system which has a number of interchangeable workpiece support fixtures, each configured to retain a given set of component workpieces or parts to be joined in a desired orientation of welding, and wherein the workpiece support fixtures may be removed from or inserted into the welding system as a modular component, depending upon the configuration of the component parts and desired blank to be formed.
Another object of the invention is to provide an apparatus used to weld two or more sets of sheet metal component workpieces, and which includes two or more modular workpiece support fixtures which carry a positioning mechanism used to position and secure the workpiece sheets in the desired orientation during welding, and which are adapted for simplified removal and/or insertion into the apparatus.
Another object of the invention is to provide an apparatus used in the production of tailored blanks, and which includes a workpiece support fixture which permits simplified and accurate qualification or positioning and clamping of a set of two or more component workpiece sheets in a desired orientation for welding.

Another object of the invention is to provide an apparatus for use in welding adjacent edge portions of component workpiece sheets made from steel, steel alloy, aluminum, aluminum alloy, titanium and/or other metals along a seamline, and which is characterized by at least one and more preferably two or more component fixtures which include a magnetic clamping mechanism used to releasably secure the sheets in a desired position during welding.
A further object of the invention is to provide high speed welding apparatus which may be easily and inexpensively modified to concurrently manufacture two tailored blanks having different configurations and/or weld characteristics.
To achieve at least some of the foregoing objects, the present invention provides an apparatus for use in welding together at least one, and preferably two or more sets of workpieces in the production of an associated component. The apparatus includes a welding station, a workpiece transport apparatus and a component transport apparatus. The workpiece transport apparatus is adapted to move each individual set of workpieces which are used to form an associated component blank from a supply position to the welding station, and may for example, comprise a vacuum or magnetic lift, a conveyor or a shuttle. Similarly, the component transport apparatus may comprise a lift, a conveyor or other suitable mechanism used to convey the completed blank to an off feed position following welding.
The welding station includes one or more welding assemblies each having one or more corresponding weld heads and at least one and preferably two, three or more workpiece support fixtures which are each used to support an individual set of parts in a desired position for welding. The workpiece support fixtures preferably each include a clamping assembly for releasably securing the set of workpieces to be joined in the welding orientation during welding operations. Each weld head is adapted to emit a weld beam, such as a plasma beam or coherent light source, along adjacent portions of the workpieces to be joined, to form a weld seam.

Although not essential, the workpiece support fixtures most preferably also include a modular base which permits the simplified removal and/or insertion of each support fixture into the welding station. The use of a modular base advantageously enables the removal of a support fixture which is adapted to support and clamp a set of workpieces used to form a component, such as a tailored blank having a first configuration, and the substitution therefor with a support fixture having a positioning and clamping arrangement which is adapted to clamp a second set of workpieces used to form a different component blank.
Most preferably, a pair of support fixtures are disposed in the welding station in a side-by-side arrangement, laterally adjacent each other, with the welding assembly further including a laterally movable weld head base or support to which the weld head is mounted.
The weld head support enables the weld head to be moved in at least one direction across at least part, and more preferably substantially all of the workpieces retained by either workpiece support fixture. The welding assembly may thus be used to weld together a set of workpieces retained in either of the support fixtures in the production of component blanks.
Although not essential, in a simplified embodiment, the workpiece transport apparatus and component transport apparatus comprise longitudinally spaced vacuum lifts which are configured for simultaneous movement in the longitudinal direction. In one such construction, each of the lift apparatus may also be independently movable in a lateral direction, as for example on an associated transverse support which is carried by an overhead gantry.
In a preferred embodiment, each welding assembly includes a laser welding head adapted to emit a single or multiple coherent light source beam from a yttrium aluminum garnet (YAG), Nd. YAG, COZ or other laser. Where a YAG laser is provided, the welding station may also includes an enclosure wall which extends about the periphery of the welding station, and which is constructed so as to substantially optically isolate the emitted coherent light source beam.
Most preferably, the welding head is mounted for three axis movement in each of the x and y horizontal axis, as well as the vertical z axis. Optionally, for decreased production time, a pair of welding assemblies may be included, oriented so as to locate a welding head on opposing sides of the workpiece support fixtures, and which are configured for simultaneous operation.
The support fixtures preferably also include a part positioning system configured to assist in qualifying or locating the individual workpieces of each workpiece set in an optimum welding position thereon. Suitable locating mechanisms may include the use of fixed stops or retractable locating pins, such as those disclosed in United States Patent No. 6,011,240, the disclosure of which is incorporated herein by reference. Most preferably, however, the positioning system includes one or more locating rods which are movable on a sliding pneumatic, electric or hydraulic cylinder, and which engage a side portion of at least one workpiece to slide the workpiece until it achieves a desired position. In a simplified construction, the locating rod may consist of a round or oval steel or metal pin which is adapted to engage a complementary sized edge or groove, and more preferably an inwardly extending V-shaped groove formed in a peripheral or waste-stock portion of a given workpiece.
In use of the welding apparatus, the workpiece lift assembly is used to move a set of workpieces to be joined longitudinally into the welding station from the component workpiece supply stack, and onto a first one of the support fixtures. Although not essential, most preferably simultaneously with the movement of the set of workpieces from the workpiece component supply stack, the component lift apparatus is used to lift the completed blank from the support fixture and convey it from the welding station to an outfeed position, as for example onto a pallet or a magnetic conveyor for movement through post weld inspection, grinding and/or oiling stations. It is to be appreciated that for increased production speed, the longitudinal movement and positioning of each set of workpieces and the movement of the finished blank to and from one support fixture may occur simultaneously with the operation of the welding assembly to weld together workpieces secured positioned on the second other support fixture.
Accordingly, in one aspect the invention resides in an apparatus for joining proximal edge portions of at least two workpieces along a weld seam to form a component including, a welding station comprising, a plurality of support fixtures, at least one of said support fixtures being removable from said welding station and operable to releasably retain said workpieces in a welding position thereon with the proximal edge portion of a first one of said workpieces in substantially abutting contact with the proximal edge portion of a second other workpiece, a welding assembly including a weld head selectively operable to emit a welding beam at said edge portions to form said weld seam and a support for said weld head, said support movably supporting said weld head for movement therewith along at least part of said weld seam, and a controller for controlling the operation of the weld head to emit said welding beam in response to the edge configuration of the workpieces retained in the welding position.
In another aspect, the present invention resides in an apparatus for the concurrent manufacture of at least two component blanks by joining proximal edge portions of first and second associated pairs of workpieces along a weld seam, the apparatus including, a welding station comprising, a first support fixture for releasably retaining said first associated pair of workpieces in an orientation with their proximal edge portions in substantially abutting contact, a second support fixture for releasably retaining said second associated pair of workpieces in an orientation with their proximal edge portions in substantially abutting contact, the second support fixture being disposed substantially laterally adjacent to said first support fixture, a laser welder having a first welding head for emitting a coherent light source, the welder being selectively movable between a first position adjacent said first support fixture to weld at least a portion of said proximal edge portions of at least one of said first pair of associated workpieces to form a first blank, and a second position adjacent said second other support fixture to weld said second pair of associated workpieces to form a second blank, a conveying apparatus comprising, a workpiece lift operable to move an associated pair of workpieces from a supply position to one of the first or second support fixtures, and a component lift operable to move a component blank from one of the first or second support fixtures to an offload position.
In a further aspect, the present invention resides in an apparatus for the concurrent manufacture of two or more tailored blanks by joining the abutting edge portions of first and second associated pairs of sheet metal workpieces along a weld seam, the apparatus including, a welding station comprising, a first support fixture for releasably retaining said first associated pair of workpieces in a welding position with their proximal edge portions in substantially abutting contact, the second support fixture being disposed substantially laterally adjacent to said first support fixture, a laser welding apparatus having a welding head for emitting a coherent light source, the welding head being selectively movable in a lateral direction between a first position adjacent said first support fixture where said welding head is operable to weld at least a portion of said edge portions of said first pair of associated workpieces to form a first blank and a second position adjacent said second other support fixture where said welding head is operable to weld at least part of said edge portions of said second pair of associated workpieces to form a second blank, each of said first and second support fixtures having a modular base adapted for selective positioning within or removed from said welding station, a conveying apparatus comprising, a workpiece lift selectively operable to move at least one of said associated pairs of workpieces from a supply position to a selected one of the first or second support fixtures, and a component lift selectively operable to move at least one of said blanks from a selected one of the first or second support fixtures to an offload position.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be had to the detailed description taken together with the accompanying drawings in which:
Figure 1 shows a schematic plan view of a high speed welding apparatus in accordance with a preferred embodiment of the invention;
Figure 2 shows a partially cut away perspective view of the welding apparatus of Figure l;
Figure 3 shows a schematic side view of the welding apparatus of Figure 2;
Figure 4 shows a plan view of a supply pallet for storing sets of individual component workpiece pans used in the welding apparatus of Figure 1;
Figure ~ shows an enlarged perspective view of a suction lift used to convey a set of workpieces in the apparatus of Figure l;
Figure 6 shows an enlarged perspective view of a modular workpiece support fixture for use in the apparatus of Figure l;
Figure 7 shows a partial plan view of a support fixture for use with the apparatus of Figure 1;
Figure 8 shows an enlarged partial exploded view of a telescoping positioning rod used in the alignment of the workpiece parts on a support fixture;
Figures 9a and 9b show the sequential positioning of the component workpieces on the support fixture for use with the present invention;
Figure 10 shows a partial schematic side view of the apparatus of Figure 1 with the workpiece and component lift apparatus moved to an upstream position; and Figure 11 shows a schematic side view of the apparatus of Figure 9 with the workpiece and component lift apparatus moved to a downstream position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Figures 1 to 3 illustrate a high speed welding apparatus 10 which is adapted for the concurrent positioning and/or welding of two discrete sets of component workpieces 12a, 12b in the manufacture of corresponding associated tailored blanks 14 to be used in the manufacture of vehicle body panels. Figure 2 shows best the apparatus 10 as consisting of a workpiece supply station 16, a welding station 18, a tailored blank off feed station 20.
Optionally, the welding apparatus 10 may be provided with additional processing stations for the further modification of the welded blanks 14. By way of non-limiting example, the blanks 14 may be moved longitudinally from the off feed station 20 by means of a vacuum conveyor, or when welding ferrous materials, a magnetic conveyor 22 through one or more of a post weld inspection apparatus 24, a dimpling press 26, and an oiling station 28. Following any additional processing, the blanks 14 are moved by a turn-over robot 30 and ultimately depending on whether the weld seams formed in the blank 14 fall within acceptable tolerances, positioned on either a desired shipping pallet 34a,34b, or a reject pile 36 by the use of an off loading robot 38.
Figure 4 shows best the two sets of workpieces 12a,12b as each consisting of 5 separate individual component workpieces or parts 40a,40b,40c,40d,40e. The component parts 40a-a of the workpiece set 12a are identical to the respective component parts 40a-a of the workpiece set 12b, with the result that when joined, the component parts 40a-a of each workpiece set 12a,12b form the identical tailored blank. The component parts 40a-a consist of substantially flat steel, steel alloy, aluminum or other metal or alloy sheets which most preferably have differing thicknesses, depending upon the strength requirements of the corresponding portion of the tailored blank 14 to be formed. The component parts 40a-a are further characterized by a peripheral waste portion (shown in phantom as 15 in Figure 4a), which, following the welding of the individual parts 40a-a to form the tailored blank 14, is ultimately removed or otherwise does not interfere with the final production of the vehicle part during subsequent processing of the blank 14.
As will be described hereafter, the welding apparatus 10 includes an overhead gantry 42 which is configured to move either set of workpieces 12a,12b in the longitudinal direction of axis A-A1 (Figure 1 ) from the workpiece supply station 16 into the welding station 18; and following the welding of the parts 40a-e, thereafter move the tailored blank 14 to the off feed station 20.
Figures 1 and 2 show best the overhead gantry 42 as being movable on a pair of longitudinally extending parallel horizontal support rails 44a,44b which extend the entire longitudinal length of at least the supply station 16, welding station 18 and off feed station 20.
Figure 2 shows best the horizontal support rails 44a,44b as being suspended vertically a distance of between about 2 and 6 metres above the floor 46 on a series of vertical support beams 48. In a simplified construction, the gantry 42 has a generally square frame construction and includes a pair of parallel transversely oriented frame members 50,52 which extend normal to the axis A-A,, and which are joined at each end by a connecting slide frame member 54,56. A slide motor 58 is coupled to the connecting frame member 56 and engages a track 59 which extends longitudinally along the support rail 44B. The motor 58 may be selectively actuated to reciprocally slide the frame members 50,52,54,56, as a unit, longitudinally along the support rails 44a,44b between an upstream position with the frame member 50 is moved directly above the supply station 16 and the frame member 52 located directly above the welding station 18, and a downstream position where the frame member 50 moves over the welding station 18 and the frame member 52 is moved to the position shown in phantom in Figure 1, directly over the off feed station 20.
The workpiece supply station 16 is shown at an upstream end of the welding apparatus 10. A pair of parallel spaced steel rails 60 extend in the lateral direction into and more preferably across the supply station 16. The rails 60 are positioned under the support rails 44a,44b extending from respective loading positions on each lateral side of the apparatus 10. A
pair of wheeled sleds 62a,62b are adapted to be selectively moved along the rails 60 into a supply position (shown by sled 62b in Figure 1 ) approximately beneath an upstream positioned frame member 50. Figure 4b shows best each sled 62a,62b as movably supporting a workpiece supply pallet 64 used in the supply and positioning of a number of sets of workpieces 12a,12b at the supply position. A series of cylindrical cone locators 66 extend upwardly from the base 68 of each pallet 64. The cone locators 66 assist in positioning the individual component workpieces 40a-a in approximately the same orientation as the workpieces 40a-a assume during welding to form the associated tailored blank 14.
Figure 1 shows the workpiece supply station 16 as having a preferred lateral width selected to permit the simultaneous positioning of both wheeled sleds 62 with supply pallets 64 thereon beneath the frame member SO in a supply position. It is to be appreciated that although not essential to the invention, this configuration advantageously permits an empty supply pallet 64 to be replaced on one wheeled sled 62, while the second wheeled sled remains in the supply position, reducing any downtime which could otherwise be necessitated by the substitution of supply pallets. It is to be appreciated that in a simplified embodiment, supply pallets are moved by a fork lift 70 onto a sled 62 which has been rolled along the rail 60 laterally from beneath the gantry 42 to the loading position of sled 62a shown in Figure 1. The movement of the wheeled sled 62 along the rails 60 may be achieved in a number of possible manners including by way of a direct drive motor, by the use of a winch or pulley drive, or even by the manual positioning of the sleds 62. In either a supply or loading position, the sleds 62 may be secured in place by locking the drive, or for additional safety, either by the use of a locking brake (not shown) or by a releasable pin or bolt coupling.
Figure 2 shows best a workpiece lift apparatus 76 and a component blank lift apparatus 78 as being carried on a transverse frame member 50,52, respectively, for reciprocal movement longitudinally together with the gantry 42.
The workpiece lift apparatus 76 is movable laterally along the upstream transverse frame member 50. The lift apparatus 76 includes a drive motor 80 which engages an elongated laterally extending slide 82 secured to the frame member 50. The motor 80 is operable to selectively move the lift apparatus 76 in the lateral direction along the frame member 50. In particular, the operation of the motor 80 is controlled by means of a CPU 100 (Figure 1 ) to selectively move the lift apparatus 76 along the frame member 50 between laterally spaced positions above a desired sled 62 which has been moved into a supply position.
The lift apparatus 76 further includes a suction lift 84 (Figure 5) which is secured to the lowermost end of a vertical slide 86. The slide 86 is operable by means of CPU 100 to raise and lower the suction lift 84. The workpiece suction lift 84 is thus movable in the lateral direction along the frame member 50 between laterally spaced positions generally corresponding to the positioning of supply pallets 64 when in the supply position. It is to be appreciated that the distance of vertical movement of the slide 86 is selected to enable the suction lift 84 to be lowered against a selected set of workpieces 12 on one of the supply pallets 64, and raised therefrom to a sufficient height to enable any set of workpieces 12 retained thereby to be moved to the welding station 18.
Figure 5 shows best the suction lift 84 as including a generally H-shaped aluminum extrusion frame 90 and a series of vacuum caps 92. The vacuum caps 92 are spaced about the frame 90 in an orientation selected so as to engage all of the individual workpieces 40a,40b,40c,40d,40e when the lift 84 is lowered against the pallet 64. The vacuum caps 92 are selected so that when operated under a high vacuum pressure, a sufficient suction force is supplied to fixedly retain the individual parts 40a-a thereto, for both vertical and horizontal movement together with the lift 84.
Figure 5 further shows the suction lift 84 as also including a series of spring biased push down rollers 94, extending downwardly from the lower surface of the extrusion frame 90. The push down rollers 94 consist of a roller wheel 95 which is mounted to the end of a hingely movable arm 96 and biased downwardly by a compression spring 97. The arm 96 is configured so that when unbiased, the wheel 95 extends downwardly a marginal extent below that of the vacuum caps 92. The force of spring 97 biasing the wheel 95 and lower extent of the arm 96 is selected so as not to interfere with the coupling of the individual workpieces 40 to the vacuum caps 92 when the suction lift 84 is operated under a high vacuum pressure, while still applying a downward force on the individual workpiece part 40. As will be described, the incorporation of spring biased push down rollers 94 in the suction lift 84 provides an economical mechanism to ensure that the individual workpieces 40 are maintained in a substantially flat orientation during their final positioning or qualification immediately prior to welding.
Figure 2 shows best the component lift apparatus 78 as movably secured to the downstream frame member 52. Like the workpiece lift robot 76, the component lift apparatus 78 also includes a drive motor 80, a vertical slide 82 and a suction lift 84. The drive motor 80 of the component lift apparatus 78 engages an elongated slide 82 secured to the downstreammost transverse frame member 52, with the operation of the motor 80 and slide 82 also controlled by the CPU 100 to selectively move the lift apparatus 78 in the lateral direction along the frame member 52.
The suction lift 84 of the component lift apparatus 78 includes an extruded frame 90 and a series of vacuum caps 92 which are substantially identical to those of the suction lift 84 of the workpiece lift apparatus 76. The suction lift 84 of the component lift apparatus 78 is secured to the lowermost end of the vertical slide 86. The slide 84 of apparatus 78 is selected to enable the suction lift 84 to be lowered into contact with a completed tailored blank 14 positioned in the welding station 18, and raised therefrom to a sufficient height to enable its movement from the welding station 18 to the off feed station 20. More preferably, the suction lift 84 is controlled by the CPU 100 and is selectively operable to produce a sufficient vacuum force through the vacuum caps 92 to fixedly retain a completed tailored blank 14 for movement both vertically and horizontally therewith.
Figures 1 and 2 show best the assembly welding station 18 as including a peripherally extending optically opaque enclosure wall 106. The enclosure wall 106 extends upwardly from the floor 46 about the periphery of the welding station 18 to a height of approximately two meters. It is to be appreciated that the vertical slides 84 of the lift apparatus 76,78 are adapted to move in the vertical direction so as to permit the workpiece sets 12 component blanks 14, respectively, to be raised vertically above the uppermost edge of the optical enclosure wall 106 when moving into or from the welding station 18.

Within the enclosure walls 106 are housed a pair of identical interchangeable workpiece support fixtures 108a,108b and a pair of elongated welding assemblies 110a,11 Ob. Figure 1 shows best the support fixtures 108a as being mounted on, and selectively movable laterally along a pair of parallel steel rails 120. Figure 1 shows best the support fixtures 108a,108b as being positioned on the rails 120 laterally immediately adjacent to each other. The rails 120 extend from outside the apparatus 10 laterally across the middle of the welding station 18. As will be described, the support fixtures 108a,108b are selectively movable along the rails 120 to enable their removal from and/or substitution into the welding station 18 as a modular component. A movable access door 122 (Figure 2) is provided through one side of the enclosure 106 at the rails 120. The door 122 may be opened to permit the substitution of different support fixtures 108 when, for example, the welding assembly 10 is to be reconfigured for welding different blanks 14 and/or types of components.
The welding assemblies 11 Oa, l l Ob are positioned on respective downstream and upstream sides of the rails 120 and support fixtures 108a,108b. The welding fixtures 11 Oa, l l Ob have the identical construction and are adapted to deliver laser energy from a respective YAG
laser 124a,124b (Figure 1 ) to workpiece parts which are moved to a welding position on the support fixtures 108a,108b. Laser energy is preferably provided by a pair of four kilowatt YAG
lasers 124a.124b, however, lasers of other types and/or power may also be used. As seen best in Figure 3, each welding assembly 110 includes a laser head 128, a supporting girder 130 used to support the laser head 128 over the workpiece parts 40a-e, and a laterally movable base 132.
Most preferably, the laser head 128 of each fixture 11 Oa, l l Ob is coupled to a respective YAG
laser 124a,124b by means of a fibre optic cable 134 (Figure 1 ) and further is adapted to emit a twin spot coherent light source along the abutting edge portions of the parts 40a-a to be joined.
The support girder 130 consists of a reinforced metal frame which is elongated in the direction of axis A-A,. The girder 130 is slidably coupled to the base 132 in a cantilevered arrangement by means of a motor driven horizontal slide 138 (Figure 1) which permits movement in the longitudinal direction of axis A-A,. Preferably, the motor driven slide 138 of each welding assembly 110 is also controlled by the CPU 100, whereby the slide 138 is moved along a predetermined path. Figure 3 shows best the laser head 128 as being mounted to an endmost portion of the girder 130 for sliding movement in the longitudinal x direction, substantially across a set of workpieces 12 secured in at least one, and preferably both, of the support fixtures 108a,108b positioned within the welding station 18. The girder 130 and laser head 128 are movable horizontally in the lateral y direction together with the base 132 along an associated slide frame 140 (Figure 1 ) which extend substantially the lateral width of the welding station 18.
A CPU 100 controlled rack and pinion, screw or linear motor 142 is disposed within the base 132 and engages the slide frame 140 to move each laser head 128 the desired distance in the y direction. It is to be appreciated, that by laterally moving the girder 130 in either the x or y direction, the laser head 128 may be selectively moved across either workpiece support fixture 108a,108b to perform welding operations on the parts 40a-a positioned thereon.
Most preferably, the laser head 128 is preferably also coupled to the girder 130 by means of a CPU 100 controlled vertical slide 144 (Figure 3) which enables movement of the laser head 128 in the vertical z axis, so as to permit adjustment of the emitted coherent light source spot diameter. Figure 3 shows best each welding assembly 110 as further including a welding shroud 146 for use in containing emitted YAG laser energy. The welding shroud 146 most preferably consists of an optically opaque light barrier which partially encases the laser head 128 and is carried by the support girder 130. The shroud 146 covers and extends completely about the top and periphery of the laser welding head 128 and is open at the bottom, so as not to interfere with the delivery of the coherent light beam to the parts 40a-a to be joined.
Preferably, the lowermost edge of the shroud 146 is raised a distance above the workpiece parts 40a-a positioned on a support fixture 108 by a distance selected so that any emitted YAG light energy is not reflected above the uppermost edge of the surrounding enclosure wall 106.
Although Figures 1 and 2 illustrate the invention as including a pair of identical welding assemblies 11 Oa, l l Ob, the invention is not so limited. In a more economical and slower version, a single welding assembly 110 could be provided for forming all of the weld seams. Similarly, where increased welding speeds are desired, each welding assembly 110 could be provided with two separate laser welding heads 128, each coupled to its own girder 130 and base 132, and permanently positioned immediately adjacent to a corresponding workpiece support fixture 108a,108b.
Figures 2, 6 and 7 show best the modular support fixture 108a used with the present invention, the second other support fixture 108b having the identical construction with like reference numerals used to identify like components. The support fixture 108a includes a tubular base 150 which is mounted on two opposing pairs of wheels 152 which have a size and spacing selected so as to enable the movement of the fixture 108a through the door 122 and along the pair of parallel spaced rails 120 to assume a desired operating position within the welding station 18. A series of associated pairs of elongated electrically cyclable permanent magnets 154a,154b are removably secured to the upper surface of the base by a series of bolts (not shown) or other fasteners. The magnets 154a,154b each present substantially flat upper surfaces 156a,156b having height and size selected to support the abutting edge portions of one or more workpiece parts 40 where weld seams are to be formed. An elongated copper-lined trough 158 (Figure 7) extends longitudinally between each associated magnet 154a,154b. The trough 158 serves as an energy dump for coherent light source energy during welding. The number and arrangement of magnets 154a,154b are secured on the base 150 in an orientation so that the position of one trough 158 generally corresponds to the orientation of each abutting portions of the component workpieces 40a-a which are to be joined along the weld seams.
Figure 6 further shows best the support fixtures 108 as including a series of horizontal supports 160, as well as fixed positioning rods 162 and movable positioning rods 164. The horizontal supports 160 consist of a steel, aluminum or other metal posts which extend upwardly from the base 150 substantially the same height as the upper surfaces 156a,156b of the magnets 154a,154b. It is to be appreciated that the horizontal supports 160 are used to support the underside of the individual workpiece parts 40a-a in the desired horizontal orientation during welding. Although not essential, the horizontal supports 160 are preferably removably coupled to the base 150 and may, for example, be adjustable in height to permit a greater flexibility of the welding apparatus 10.

The positioning rods 162,164 (Figures 7 and 8) operate to guide the individual workpiece parts 40a-a in the desired orientation on the support fixtures 108 during welding. In particular, the positioning rods 162,164 are each provided with a generally cross-sectional circular profile with a radius selected at between about 0.5 to 3.0 cm. The cylindrical shaft portion of each positioning rod 162,164 has a vertical height which is selected so as to extend above the horizontal supports 160 and upper surface 156 of each elongated magnet 154a,154b. With this configuration, the positioning rods 162,164 extend into engagement with the peripheral waste edge portion 15 of one or more of the workpiece parts 40a-e. Preferably, the individual workpieces 40a-a are formed having one or more V-shaped locating grooves 168 in the waste portion 15. The locating grooves 168 extend inwardly from the peripheral edge of the workpiece to a central bite 176.
As shown best in Figures 7 and 8, the movable locating rods 164 are secured to one end of a horizontally movable pneumatic slide 170, and may in turn be mounted for movement on a pneumatic sliding sub-frame 172. Figure 8 shows best the sub-frame as consisting of a rigid bar 180, which spatially connects an opposing pair of locating rods 162,164. The bar 180 is coupled to a telescoping member 182 at a pivot 184 for horizontal pivoting movement in the direction of arrow 204. The telescoping member 182 is activated in movement by a pneumatic cylinder 188, and is further positioned for sliding movement in a direction generally normal to that of the pneumatic slide 170.
In operation, the horizontal slide 170 moves the rod 164 in the direction of arrow 200 (Figure 8) against the part 40a. The positioning rods 162,164 are positioned so as to locate at least approximately within an associated locating groove 168 formed in a component workpiece 40a-e, at pre-selected positions depending on the blank 14 configuration. Most preferably, the movable positioning rods 164 are provided either paired with a fixed positioning rod 162 or with an associated movable positioning rod 164 on opposing peripheral portions of the workpiece part 40. As a result of the circular cross-section of the rods 162,164, as the workpiece 40a-a and locating rod 162,164 move together relative to each other, the individual workpiece 40 tends to slide on the surface 156 of the magnets 154. In particular, as the locating rod 162 or 164 moves inwardly towards the bite 176 of the groove, at least one of the sides of the groove 168 will engage the circumferential surface of the rod 162,164 until it assumes an orientation fully seated adjacent the groove bite 176. It is to be appreciated that as the movable rod 164 engages the sides of the locating groove 168, the component workpiece 40 is slid not only relative to the movable rod 164, but also relative to the opposing fixed or movable positioning rod 162,164 or previously positioned part 40. The movement of the workpiece 40 against an opposing rod or part 40 causes the sliding adjustment in the lateral orientation of the workpiece part 40 relative to the rods 162,164 to assume a desired orientation over at least one of the magnets 154. It is to be appreciated that once a first workpiece part 40e is secured in the desired position, the underlying magnet 154 is activated to fixedly retain it in place. Thereafter, the edge portion of the secured workpiece 40e, which is proximate the edge portion of the next workpiece 40b, may be used in conjunction with other fixed and movable positioning rods 162,164 to assist in orienting the next workpiece 40d in the desired abutting relationship over the second other underlying magnet 154b in a like manner. To draw one workpiece 40d into contact with a next adjacent workpiece 40e, the pneumatic cylinder 188 of the sub-frame 172 is then activated to draw the part 40d in the direction of arrow 202 (Figure 8).
The push down rollers 94 are used in the final positioning of the workpieces 40 on a support fixture 108 to prevent one workpiece 40d from riding overtop of the adjacent workpiece 40e as the abutting edge portions are moved together. In particular, the downward force applied by the spring 97 ensures that the edge portions of the workpieces 40d,40e are maintained flat against the magnet surfaces 156a,156b as the edges of the workpieces 40d,40e are moved into dabutting contact. While Figure 5 shows a roller 94 arrangement for the workpieces, it is to be appreciated that other mechanisms for maintaining downward pressure on the workpiece parts 40 are also possible, including without restriction the use of a 360°
rotatable roller ball, suction hold-down tables or pressure pads or the like.
The individual support fixtures 108a,108b may be temporarily secured within the welding station 18 during its operation by a number of conventional manner. For example, it is possible to secure the support fixtures 108a, l OSb in the desired operating position by the use of removable bolts or pins (not shown), or by the use of a locking motor or manual brake.
With the present invention, the support fixtures 108a,108b,108c,108d (Figure 1 ) each have the identical base 150 structure, permitting the support fixtures 108c,108d to be interchanged for the support fixtures 108a,108b in a modular fashion. In particular, by using modular support bases 150 having the identical construction, and reconfiguring the position of the magnets 154, horizontal supports 160 and positioning rods 162,164, it is possible to substitute a different support fixture configuration which is adapted to secure different shaped workpiece parts during welding. Furthermore, the modular wheeled nature of the support fixtures 108 allows the welding apparatus 10 to be rapidly and easily re-configured for different part manufacture. In particular, to reconfigure the welding apparatus 10, the pins or bolts used to secure the support fixture 108a,108b in the operating position within the enclosure 106 are removed, and the access door 122 through the enclosure wall is opened. The support fixtures 108a,108b are thereafter wheeled laterally from the welding station 18 along the rails 120 for maintenance, storage and/or reconfiguration. Substitute support fixtures 108c,108d are thereafter positioned on the rails 120 by the use of a forklift 70 or other means, wheeled into the welding station 18 and secured in place in the opposite manner. It is to be appreciated that the modular nature of the support fixtures 108 allows substitute support fixtures 108c,108d to be readied while the welding apparatus 10 is operated to produce a first component blank 14 product run.
Furthermore, the CPU 100 is more preferably pre-programmed to control movement of the lifts 76,78, lasers 124a,124b and welding slide frames 138,144 to move the emitted weld beam along a pre-selected series of movements, depending upon the configuration of a given support fixture 108 and workpiece set 12 which has been secured within the welding station 18.
In use of the apparatus, the sets of workpieces 12a, 12b and component blanks 14 are conveyed longitudinally in the direction of axis A-A, from supply positions at the supply station 16, through the welding station 18, and then subsequently onto the conveyor 22 at the off feed station 20 for movement past the post weld inspection robot 24, dimpling press 26, oiling station 28 and then to output stacks on the pallets 34a,34b.

Initially, a supply pallet 64 having a number of sets of workpieces 12 positioned thereon is moved onto the respective sled 62b by means of a forklift 70. The sled 62b is then rolled laterally along the rails 60 to the supply position shown in Figure 1 between the support rails 44a,44b. It is to be appreciated that to avoid any lapse in production time, while workpiece sets 12b are removed from the pallet 64b in a supply position, a second supply pallet 64a may be loaded on the second other sled 62a for movement into the apparatus 10.
Initially, as shown in figure 10, the overhead gantry 42 is moved longitudinally along the rails 44a,44b to an upstream position so that the workpiece lift apparatus 76 is positioned directly above the supply pallet 64b on sled 62b. The suction lift 84 is then lowered to bring the vacuum caps 92 into contact with the individual workpieces 40a-a which comprise the set 12b. The suction lift 84 is then activated to produce a sufficient suction force through the caps to fixedly retain all the workpieces 40a-a to the frame for movement therewith. Following the activation of the vacuum caps, the extrusion frame 90 and workpiece array 12b is raised by means of the vertical slide 86 to a position above the uppermost vertical height of the enclosure wall 106.
As shown in Figure 10, although not essential the lateral frame member 52 is most preferably spaced from the lateral frame member 52 by a distance selected so that the component blank lift apparatus 78 assumes an orientation directly above the transversely positioned support fixtures 108a,108b located in the welding station 18, when the workpiece lift apparatus 76 is moved above the sled 62b. With this configuration, the component lift apparatus 78 may be operated simultaneously with the workpiece lift apparatus 76. As the workpiece lift apparatus 76 is lowered to retain and raise a set of workpieces 12b array, the component lift apparatus is used to retain and raise a welded component blank 14 from the support fixture 108b.
As with the workpiece lift apparatus 76, the slide 82 of the component blank lift apparatus 78 is activated to lower the frame 90 and move the vacuum caps 92 into contact against the welded blank 14.
Once in position, the suction lift 84 of the lift apparatus 78 is activated to produce a sufficiently high vacuum pressure to fixedly retain the blank 14 to the component lift apparatus 78 for movement therewith. The vertical slide 82 is then activated to raise the frame 90 and retain component blank 14 to a vertical height above the enclosure wall 106.
Once the retained component 14 and workpiece set 12b are moved to the raised position, the slide motor 58 is activated to move the gantry 42 longitudinally towards the off feed station 20 to a downstream position so that the frame member 50 to which the workpiece lift apparatus 76 is mounted is moved directly above the support fixtures 108a,108b and the component blank lift apparatus 78 is moved to the off feed station 20 directly above the magnetic conveyor 22 used to move the completed blank 14 past the post weld inspection robot 24.
The blank lift apparatus 78 is thereafter activated to lower the frame 90 and the suction lift 84 is then deactivated to release the welded blank 14 onto the magnetic conveyor 22.
Concurrently with the positioning of the welded blank 14 on the magnetic conveyor 22, the workpiece lift apparatus is moved laterally along the frame member 50 to assume an orientation over the now empty support fixture 108b from which the welded blank has been most recently conveyed. The slide 82 of the workpiece lift apparatus 76 is then activated to lower the suction lift 84 and retain workpieces set 12b onto approximately a desired position so as to rest on the upper surfaces 156 of the magnets 154, and horizontal supports 160 of the support fixture 108b.
With the individual workpieces 40a-a positioned on the sets of magnets 154a,154b, the push down rollers 94 suspended by the frame 90 engage and apply a downward pressure against the upper surface of the individual workpieces 40a-e. With the suction lift 84 deactivated, and the push down rollers 92 engaging the upper surfaces of workpieces 40a-e, the positioning rods 162,164 are operated so that the individual parts 40a-a are sequentially secured in the desired final welding position on the support fixture 108b through the engagement of the locating rods 162,164 within positioning grooves 168.
Once an initial workpiece part 40e is moved in the desired orientation, the arrays of magnets 154a which support the proximal edge to be welded are activated to clamp the workpiece 40e in force. The next workpiece 40d is thereafter positioned by the use of the positioning rods 162,164, its engagement with the clamped edge of the initially positioned workpiece 40e, and the relative movement of the workpiece and positioning rods 162,164. Each subsequent workpiece 40a,40b,40c forming the workpiece array is sequentially positioned in a like manner, until all of the workpieces 40a-a achieve the desired position on the support fixture 108b for welding. Thereafter, the suction lift 84 is deactivated and the frame 90 is returned moved to the raised position for return movement with the gantry 42 to the upstream position.
For decreased manufacturing times, welding of the set of workpieces I2 secured in the other support fixture I08a is performed concurrently with the movement and positioning of workpieces 40 on the support fixture 108b. In particular, once a workpiece set 12 has been secured in the welding position on a fixture 108, and the suction lift of the workpiece lift apparatus 76 raised therefrom, the CPU 100 is used to activate both welding assemblies 11 Oa, l l Ob to move along the sliding frame 140 to positions immediately upstream and downstream from the newly secured workpieces. The lasers 124a, I24b are simultaneously operated to emit a twin spot welding beam from each respective laser head 128.
Simultaneously, the CPU 100 controls the slide motor 138 to move each support girder 130 both forwardly and rearwardly in the longitudinal direction, while laterally moving the base I32 to move the laser heads 128 and their emitted beams along the abutting edge portions of the workpieces 40 to be joined. Concurrently with the welding operation, the laser heads 128 are vertically raised or lowered on their vertical slides 144 to maintain the desired focal spot diameter at the workpieces 40a-e.
Following welding of the workpieces 40a-a to form the welded blank 14 at the support fixture 108a, and most preferably concurrently with the movement of the overhead gantry 42 to return the workpiece lift assembly 76 to the downstream position, the motors are activated to return each welding head 128, girder 130 and base 132 along the slide frame 140 adjacent to the other fixture 108b to weld the parts 40a-a thereon. Concurrently, the component blank lift apparatus 78 is used to move the next welded component blank 14 from the support fixture I08a to the outfeed station 20. It to be appreciated that with the present apparatus, positioning and welding of the workpiece sets 12 is alternately performed in each support fixture 108a,108b with the lift apparatus 76,78 moving laterally along the transverse frame members 50,52 respectively to the desired orientation.

The component off feed station 20 where the completed component blanks 14 are moved following welding consist of magnetic or vacuum conveyor 22 and one or more post-weld processing stations. Preferably, the post weld inspection robot 24 is provided at the off feed station 20 to sense one or more characteristics or profiles of the formed weld seams. The completed blank 14 is moved downstream via the conveyor 22 in a longitudinal processing direction from the post weld inspection robot 24 via further magnetic conveyor 224 (Figure 3) for further processing through the dimpling press 26 to form dimples at desired positions within each manufactured component blank 14 and the oiling station 28. Following oiling, the blanks 14 are flipped by means of the turnover robot 30 and are thereafter stacked by means of the reciprocating off loading robot 38 onto either an output stack 34a,34b pallet or the reject pile 36, depending upon the criteria sensed by the post weld inspection robot 24.
Although the preferred embodiment of the invention describes the apparatus 10 as including a pair of identical modular support fixtures 108a,108b used to simultaneously form the same component blanks 14, the invention is not so limited. The present apparatus 10 may equally be provided to simultaneously weld together different sets of workpieces 12, including without limitation, simultaneously producing both the right hand and left hand tailored blanks 14 or unrelated parts for use in the automotive, rail, aircraft and/or other industries, as may be desired.
While the preferred embodiment of the invention discloses the use of positioning rods having a circular cross-section and generally V-shaped positioning in grooves, the invention is not so limited. It is to be appreciated that positioning rods and/or locating grooves of other shapes and configurations are equally possible and will now become readily apparent.
While the preferred embodiment of the invention discloses the component blank lift assembly 78 as being secured for direct movement with the workpiece lift assembly 76, the invention is not so limited. It is to be appreciated that the lifts 76,78 may move independently from each other, as for example along separate gantry systems.

While the preferred embodiment of the invention discloses the final processing of the welded blanks 14 by movement through a post weld inspection station 24, dimpling apparatus 26 and oiling station 28, it is to be appreciated that additional or other processing stations including grinding stations, spray stations and the like could also be used with the present invention.
Although in one simplified construction, the modular base 150 of each workpiece support fixture 108 is movable into and from the desired operational position within the welding station 18 along a rail system consisting of one or more rails 120, the invention is not so limited. Other modes of positioning and conveying of the support fixtures 108 into and from the welding station 18 are also possible, including without restriction, motor or manual driven wheeled systems, sleds or rack and pinion-type slide.
It is to be appreciated that when welding aluminum as well as other steel parts, it may be advantageous to provide the upper clamp members above each of the magnets 154a,154b.
Suitable upper clamp configurations would include without limitation the ferromagnetic hold down shoes disclosed in United States Patent No. 6,011,240.
It is to be further appreciated that where simplified support fixture constructions are desired, or where non-qualified blanks are to be used, standard qualification apparatus such as pushers and the like could also be incorporated within the apparatus 10.
Although the detailed description describes and illustrates many preferred embodiments of the invention, the invention is not so limited. Many modifications and variations will now occur to persons skilled in the art. For a definition of the invention, reference may be had to the appended claims.

Claims (22)

1. An apparatus for joining proximal edge portions of at least two workpieces along a weld seam to form a component including, a welding station comprising, a plurality of support fixtures, at least one of said support fixtures being removable from said welding station and operable to releasably retain said workpieces in a welding position thereon with the proximal edge portion of a first one of said workpieces in substantially abutting contact with the proximal edge portion of a second other workpiece, a welding assembly including a weld head selectively operable to emit a welding beam at said edge portions to form said weld seam and a support for said weld head, said support movably supporting said weld head for movement therewith along at least part of said weld seam, and a controller for controlling the operation of the weld head to emit said welding beam in response to the edge configuration of the workpieces retained in the welding position.

2. The apparatus as claimed in claim 1 wherein each of said support fixtures further comprise a selectively operable clamping assembly for releasably securing said workpieces during welding, and wherein said welding beam comprises a coherent light source.

3. The apparatus as claimed in claim 2 wherein said clamping assembly includes an elongated array of electrically switchable permanent magnets.

4. The apparatus of claim 3 wherein a first one of said workpieces includes a peripheral waste stock portion and at least one locating recess formed in said waste stock portion, said apparatus further including a positioning mechanism for orienting said workpieces on said at least one support fixture, the positioning mechanism including a horizontally movable locating member sized to engage at least part of at least one said locating recess.

5. The apparatus of claim 4 wherein said recesses comprise a generally V-shaped groove extending inwardly from a peripheral edge portion of said blank to an innermost bight, and said locating member includes a peripheral surface configured to locate within said groove adjacent said bight when said workpiece assumes said welding position.

6. The apparatus of claim 4 wherein said magnets are selectively operable at at least a first power level, to produce a magnet field of a first intensity selected to substantially fixedly retain a workpiece thereon, and a power level reduced from said first power level to produce a sufficiently reduced magnetic field selected to enable the lateral sliding of said workpiece thereon.

7. The apparatus of claim 1 wherein a first one of said workpieces includes a peripheral waste stock portion and at least one locating recess formed in said waste stock portion, said apparatus further includes a positioning mechanism for orienting said workpieces on said at least one support fixture, the positioning mechanism including a horizontally movable slide and a locating member sized to engage at least part of at least one said locating recess mounted to said slide for movement therewith.

8. The apparatus of claim 4 wherein each of said support fixtures further comprise an interchangeable movable base, each of said clamping assembly and positioning mechanism being mounted to said base for movement therewith, and wherein the arrangement of the clamping assembly and positioning mechanism on the base is dependent upon the configuration of the component.

9. The apparatus of claim 1 further including a selectively movable gantry, said gantry being movable in a longitudinal direction and comprising at least one lateral frame member, a workpiece lift and a component lift being movably secured along said at least one frame member for movement therealong,, the workpiece lift operable to releasably retain and transport said workpieces from an upstream supply position to one of said support fixtures disposed in said welding station, the component lift being operable to releasably retain and transport said component downstream from a second other support fixture disposed said welding station, to an outfeed position.

10. The apparatus as claimed in claim 9 wherein a pair of laterally disposed support fixtures are disposed in said welding station, and said gantry comprises a pair of longitudinally spaced lateral frame members, said workpiece lift being movable along a first one of said frame members for movement therewith, and said second workpiece lift being secured to the second other of said frame members, and wherein the workpiece lift is selectively laterally movable to position said workpieces on a selected first one of said laterally disposed support fixtures, and the component lift is selectively laterally movable to move a component from the second other one of said support fixtures to the outfeed position.

11. The apparatus as claimed in claim 10 wherein said support includes a laterally movable base movable therewith between a first operating position adjacent workpieces secured to said first support fixture, and a second operating position adjacent workpieces secured to said second support fixture.

12. The apparatus as claimed in claim 11 wherein said support further comprises a reciprocally movable beam and a drive motor selectively operable to move said beam in the longitudinal direction, the weld beam being mounted towards an end portion of said beam.

13. An apparatus for the concurrent manufacture of at least two component blanks by joining proximal edge portions of first and second associated pairs of workpieces along a weld seam, the apparatus including, a welding station comprising, a first support fixture for releasably retaining said first associated pair of workpieces in an orientation with their proximal edge portions in substantially abutting contact, a second support fixture for releasably retaining said second associated pair of workpieces in an orientation with their proximal edge portions in substantially abutting contact, the second support fixture being disposed substantially laterally adjacent to said first support fixture, a laser welder having a first welding head for emitting a coherent light source, the welder being selectively movable between a first position adjacent said first support fixture to weld at least a portion of said proximal edge portions of at least one of said first pair of associated workpieces to form a first blank, and a second position adjacent said second other support fixture to weld said second pair of associated workpieces to form a second blank, a conveying apparatus comprising, a workpiece lift operable to move an associated pair of workpieces from a supply position to one of the first or second support fixtures, and a component lift operable to move a component blank from one of the first or second support fixtures to an offload position.

14. The apparatus as claimed in claim 13 wherein the apparatus includes a longitudinally movable overhead gantry comprising an upstream laterally extending frame member and a downstream laterally extending frame member, a workpiece lift including a motor operable to move the workpiece lift in the lateral direction along the upstream member, and the component lift are linked for simultaneous movement in a longitudinal direction.

15. The apparatus of claim 14 wherein said first support fixture is laterally spaced from said second support fixture, said workpiece lift and said component lift are independently movable in a lateral direction.

16. The apparatus of claim 13 wherein said first support fixture further includes said clamping assembly comprising an elongated array of electrically switchable permanent magnets.

17. The apparatus of claim 13 wherein said workpieces each include a peripheral waste stock portion and comprise at least one locating recess formed in said waste stock portion and apparatus further comprises a positioning mechanism including a horizontally movable slide and a locating member mounted to said slide for movement therewith to engage a portion of at least one of said recesses.

18. The apparatus as claimed in claim 13 wherein each of said first and second support fixtures further comprises a modular movable sled adapted to be selectively positioned into or removed from said welding station.

19. The apparatus as claimed in claim 18 wherein said movable sled comprises a rail-mounted movable sled.

20. The apparatus as claimed in claim 17 wherein said movable slide comprises a pneumatically operable slide.

21. The apparatus as claimed in claim 13 wherein said component blanks comprise automotive tailored blanks.

22. An apparatus for the concurrent manufacture of two or more tailored blanks by joining the abutting edge portions of first and second associated pairs of sheet metal workpieces along a weld seam, the apparatus including, a welding station comprising, a first support fixture for releasably retaining said first associated pair of workpieces in a welding position with their proximal edge portions in substantially abutting contact, the second support fixture being disposed substantially laterally adjacent to said first support fixture, a laser welding apparatus having a welding head for emitting a coherent light source, the welding head being selectively movable in a lateral direction between a first position adjacent said first support fixture where said welding head is operable to weld at least a portion of said edge portions of said first pair of associated workpieces to form a first blank and a second position adjacent said second other support fixture where said welding head is operable to weld at least part of said edge portions of said second pair of associated workpieces to form a second blank, each of said first and second support fixtures having a modular base adapted for selective positioning within or removed from said welding station, a conveying apparatus comprising, a workpiece lift selectively operable to move at least one of said associated pairs of workpieces from a supply position to a selected one of the first or second support fixtures, and a component lift selectively operable to move at least one of said blanks from a selected one of the first or second support fixtures to an offload position.