BACKGROUND ART The invention will be herein described for illustrative purposes with reference to tooling operations performed on light gauge steel members intended for use in steel-framed constructions (eg. the members may be studs, truss chords, etc).

However, the invention is not limited to this particular material or this particular field of use.

In the construction industry it is well known to use steel frames in preference to the more traditional timber frame assemblies. Such frames may be, for example, wall frames, floor frames and trusses, and the frames are typically comprised of individual steel members such as studs, chords and the like which must be fixed together by bolts or the like to form the assembled frame.

These individual steel members are typically rolled to the desired profile (eg. C- section or Z-section, for example) in a substantially continuous rolling operation, and then cut to length as required. The members also typically have holes punched in them at appropriate locations along the length thereof for ultimately receiving fixing means such as bolts for connecting one member to another

during final assembly of the frame. Holes and/or other local deformations may also be provided in the profiled members for other reasons at desired locations along the length of the member.

It is known in the art to form the holes or deformations"on-the-fly"."On-the-fly" means that the workpiece (ie. the profiled steel member) is not stationary during the tooling operation, but rather moves past the tooling station at a substantially constant and linear velocity. This dictates that the too) must move with the workpiece during the tooling operation.

Prior art tooling stations have involved tools mounted on linear actuators which have been accelerated up to match the linear speed of the workpiece, engaged with the workpiece, maintained at the workpiece speed during the tooling operation, and then disengaged from the workpiece, decelerated, and finally returned to the start location (via a reverse direction acceleration and deceleration) in readiness for the next tooling operation.

SUMMARY OF INVENTION The present invention provides a rotary on-the-fly tooling system according to the following claims. Preferred features of the invention will be apparent from the dependant claims and from the following description of the preferred embodiment.

BRIEF DESCRIPTION OF DRAWINGS The invention will now be described in a non-limiting manner with respect to a preferred embodiment in which:- FIGS 1 to 11 are a series of sequential views illustrating the present invention.

For ease of understanding, the components of the tooling system are shown as being translucent.

FIGS 1 to 6 show the tool and die converging on the workpiece.

FIG 7 shows the point of closest approach of the tool and die.

FIGS 8 to 11 show the tool and die separating after completion of the punching process.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT FIGS 1 to 11 are a series of sequential views which show a workpiece 10 being punched as it passes between opposed and synchronised counter-rotating tool assemblies 12 and 14. In the illustrated embodiment, the workpiece 10 has a profile in cross-section which is Z-shaped or, perhaps more accurately, 2- shaped.

Counter-rotating tool assemblies 12 and 14 each include a pair of co-rotating crank arms 16 and 18 which rotate about parallel and spaced axes.

Each crank arm 16 and 18 has a twin crank arm 16'and 18'which rotates about the same axis. Crank arms 16 and 16'rotate about an axis defined by shaft 20, whilst crank arms 18 and 18'rotate about an axis defined by shaft 22.

A tool mounting portion 24 (refer to FIG 2) is rotatably mounted between the distal ends of crank arms 16, 16'and 18,18'. Tool mounting portion 24 mounts a die 26 (refer to FIG 2 or FIG 4).

Tool assembly 14 is an identical, mirror image of tool assembly 12 and will not be described in detail here. However, it will be noted that the tool mounting portion of tool assembly 14 mounts a tool 28 (refer to FIG 2) which is complementary in shape to die 26.

The opposed and synchronised counter-rotating tool assemblies 12 and 14 are driven via computer controlled electric motors and are geared together for dependent rotation.

Referring to FIG 1, as the workpiece 10 enters between the opposed counter- rotating tool assemblies 12 and 14, the computer controlled electric motors are accelerated to drive crank arms 16 and 18 in rotary fashion and tool mounting portions 24 (and hence tool 28 and die 26) together as shown in FIGS 1 to 7.

FIG 8 shows the orientation in which the respective tool mounting portions 24 (and hence tool 28 and die 26) have reached the point of closest approach whereat they have co-operated to punch a hole in the workpiece or create some other type of deformation as required.

FIGS 9 to 11 show a sequence of views after the punching operation whereat the tool mounting portions 24 (and hence tool 28 and die 26) are separating and rotating away in preparation for the next operation on the next workpiece to pass between the counter-rotating tool assemblies.

It will be appreciated that FIGS 1-11 illustrate the operation of the apparatus through a portion of the cycle during which the crank arms 16,16", 18,18' rotate through approximately 180 degrees. Rotation through a further 180 degrees will see the crank arms rotate from the position seen in FIG 11 to the position seen in FIG 1.

With reference to the FIGS, it will be noted that the counter-rotating tool assemblies 12 and 14 are capable of rotating rapidly relative to the linear velocity of the workpiece 10. Thus, multiple operations can be formed on a single workpiece if desired.

It will or course be understood that during engagement of the tool and die with the workpiece, the velocity of the counter-rotating tool assemblies is matched to the linear velocity of the workpiece. However, when the tool and die are not engaged with the workpiece, the counter-rotating tool assemblies can be driven

at any velocity, or alternatively they can be held stationery if there is a delay prior to the arrival of the next workpiece. Typically, the tool assemblies accelerate after the tool and die have disengaged from the workpiece to a ready-position whereat they are ready to engage the workpiece again. They may be held at this ready-position for some time prior to the commencement of the next tooling operation.

It will be noted that the crank arms 16 and 18 (of both tool assemblies 12 and 14) rotate in a first plane whilst the tool mounting portions 24 (of both tool assemblies) rotate in a second plane which lies beneath the first plane as illustrated. Further, twin crank arms 16'and 18' (of both assemblies) rotate in a third plane which lies beneath the second plane as illustrated. Twin crank arms 16'and 18'are provided for additional rigidity and structural integrity and could in some circumstances be omitted. Put differently, the components beneath the second plane may be omitted.

It will be noted that the entire assembly is linked by gears and pinions so that no portion of the device can rotate independently of the others. Rather, drive can be introduced to the device at any point.

It will be noted that because the tool mounting portion 24 is mounted to the distal ends of the crank arms at locations spaced along the direction of travel of the workpiece 10, the tool mounting portion maintains the same orientation relative to the direction of travel of the workpiece at all times, ie the tool 28 and die 26 are maintained in a consistent orientation relative to the workpiece as they move through their opposed and arcuate paths.