Background Of The Invention A slitting apparatus having a slitter head incorporating top and bottom counter- rotatable arbors carrying at least one knife each which co-operate to slit metal strip in a longitudinal direction of the strip as the strip is passed between the arbors is known in the art. Generally, each respective arbor carries a pair of spaced apart knives that co- operate with similarly arranged knives on the other arbor to slit metal strands from along opposite side regions of the metal strip.

As the trimmed strip issues from the arbor, the scrap strands are directed to winders for coiling the scrap or to shears for cutting the scrap into short lengths for subsequently being collected. In the past, it has generally been necessary to manually direct the scrap strands to the winders or shears requiring personnel to work in the vicinity of the rotating arbors of the slitter head. This is highly undesirable from a safety view point.

The thickness of the scrap strands may vary from about 1 mm up to 12 mm or more and accordingly, manually directing scrap strands to the winders or scrap chutes can be exceedingly difficult when thicker strip is slit. The scrap strands also typically have sharp edges which again present safety hazards.

If the scrap strands are not properly aligned with or directed to the winders or shears, cobbling of the strands can occur. This generally leads to plant down time while the cobble is removed and can potentially lead to damage to the slitting apparatus itself as a result of the cobbling.

An example of a prior art slitting machine provided with chutes for receiving a scrap slit from a metal strip and which direct the scrap to shears is disclosed in United States Patent No. 4,501,177.

An example of a prior art slitting machine incorporating an arrangement for magnetically gripping scrap slit from a metal strip and for directing the scrap to a scrap winder for collection of the scrap is disclosed in United States Patent No. 4,550,881.

More particularly, the arrangement comprises a magnetic gripping head carried on an arm moveable vertically to enable the gripping head to engage and thereby grip the scrap. Once gripped, the scrap is drawn sidewardly in a direction across the slitting machine to a pinch roll drive which feeds the scrap into a spindle of a scrap winder that winds the scrap into a coil. When the scrap is coiled, the spindle is retracted and the scrap pushed off the end of the spindle whereby it falls into a storage area for subsequent collection.

Summary Of The Invention It is an aim of the present invention to address one or more problems of the prior art or to at least provide another way of handling the scrap slit from the metal strip.

Broadly, the invention relates to the handling of scrap as it is slit from metal strip and involves non-manual gripping of the scrap and drawing the scrap to receiving means for receiving the scrap, as the scrap is slit from the strip.

In an aspect of the invention there is provided a method of handling scrap slit from along metal strip as the strip is passed along slitting apparatus, wherein the method comprises the steps of : (a) feeding the strip to the slitting apparatus; (b) providing at least one gripping device with an arm for gripping said scrap; (c) moving the arm of a said gripping device to a gripping position to allow the arm to grip the scrap; (d) causing the arm to grip the scrap slit from the strip by the slitting apparatus as the scrap issues with the strip; (e) moving the gripping device along the slitting apparatus substantially in a direction of travel of the issuing said strip; and (f) using the arm to draw the scrap to receiving means for receiving the scrap.

In another aspect of the invention there is provided slitting apparatus for slitting strip in a direction along the strip as the strip is passed along the stripping apparatus, comprising: at least one gripping device with an arm for gripping scrap slit from the strip by the slitting apparatus and for drawing the scrap to receiving means for receiving the scrap, as the scrap issues with the strip; wherein the arm of the gripping device is moveable from an initial position to a gripping position for enabling the arm to grip the scrap and in a direction along the slitting apparatus for allowing the scrap to be drawn to the receiving means by the arm.

Generally, the slitting apparatus will be of the type including opposed counter rotatable arbors carrying co-operating knives for slitting the scrap from the strip. Each arbor may carry a single knife for co-operating with the knife on the other arbor to slit the strip or for instance, a pair of longitudinally spaced apart knives arranged to co- operate with those on the other arbor in the slitting of the strip.

Preferably, the arm will be movable to the gripping position in a transverse direction with respect to the direction of travel of the strip. Most preferably, the arm will be movable to the gripping position in a direction across the slitting apparatus.

Preferably, the arm will be extendable for drawing the scrap to the receiving means most usually while the gripping device is moved along in the direction of travel of the strip.

Preferably, the arm will be arranged for being returned from the gripping position to the initial position for enabling the scrap to be drawn to the receiving means for receiving the scrap with extension of the arm. The arm of the gripping device may simply be translated between those positions. Alternatively, the arm may be pivoted between the initial position and the gripping position.

The slitting apparatus may also comprise a support for supporting the issuing strip and for supporting the or each gripping device for movement in the direction of travel of the issuing strip.

Generally, the support will be adapted for clamping a leading end region of the strip and to travel with the issuing strip prior to subsequently releasing the strip.

Preferably, the support will be a traversing clamp for supporting the leading end of the region of the strip as the strip passes over a pit in which the receiving means for

receiving the scrap is positioned. The above embodiment can be achieved by mounting the or each gripping device on the traversing clamp of a conventionally known slitting apparatus without redesigning the apparatus and incurring the significant costs that would entail.

Preferably, the slitting apparatus will be provided with a pair of gripping devices for gripping scrap strands of metal as the strands are slit from along opposite side regions of the metal strip.

The or each gripping device may be hydraulically operated for causing extension and retraction of the arm, and the gripping and subsequent release of the scrap trimmed from the strip.

Preferably, the receiving means for receiving the scrap will comprise one or more winders for coiling the scrap, or shears for cutting the scrap into manageable short lengths for collection.

By using a gripping device to grip the scrap and draw the scrap to the receiving means, the need for personnel to manually direct the scrap to the receiving means may be avoided thereby substantially increasing safety associated with operating the slitting apparatus. In addition, the possibility of the scrap cobbling can be substantially reduced leading to a decrease in plant down time and so potentially, an increase in the volume of strip able to be processed by the slitting apparatus in a work shift and hence, an increase in productivity levels.

The features and advantages of the invention will hereinafter be further described with reference to a preferred embodiment of a slitting apparatus of the invention illustrated in the accompanying drawings.

Brief Description Of The Accompanying Drawings Figure 1 is a front elevational view of slitting apparatus embodied by the present invention for slitting metal strip; Figure 2 is a sectional view of the slitting apparatus of Figure 1 taken through II-II; and Figure 3 is a longitudinal sectional view of a gripping device of the slitting apparatus of Figure 1.

Detailed Description Of Preferred Embodiments Of The Present Invention The slitting apparatus 10 shown in fig. 1 comprises a slitter head 12 incorporating a pair of opposed, counter-rotatable top and bottom arbors 14 and 16. The bottom arbor carries a pair of knives spaced apart from each other therealong and which cooperate with corresponding knives on the top arbour 16 to slit strands from along opposite edge regions of metal strip 18 as the strip is unwound from a coil and fed between the arbors while being driven in counter-rotation to one another.

A support in the form of a traversing clamp 20 for supporting a leading end region of the strip 18 as the strip travels across pit 22 is carried on an overhead track 24 of the slitting apparatus 10. The traversing clamp 20 is capable of being driven backward and forward across the pit as desired in the longitudinal direction of the strip by a rack and pinion arrangement as is conventionally known.

A pair of gripping devices 26 are secured to the traversing clamp 20, each of which is pivotable about corresponding trunnions 28 by operation of hydraulic actuators 30, and are spaced apart from each other across the traversing clamp to allow for the passage of the trimmed metal strip between them as the strip issues from the slitter head 12. The

angle 0 through which each gripping device is able to be pivoted by the hydraulic actuators is indicated in fig. 2 as are the hydraulic actuators themselves.

Each hydraulic actuator 30 comprises a cylinder 32 mounted on a bracket 36 fixed on the traversing clamp 20, and an actuator rod 34 secured at one end to the adjacent gripping device 26.

The traversing clamp 20 incorporates upper and lower pinch rolls 38a and 38b spaced apart from each other by a gap 40 for receiving the leading end region of the strip 18. Once received in the gap 40, the upper pinch roll 38a is moved toward the bottom pinch roll 38b to thereby clamp the strip 18. Rather than pinch rolls, clamping jaws may be employed on the traversing clamp 20 for the purpose of clamping the strip 18.

Turning now to fig. 3, the gripping device 26, shown has an outer casing 42 within which is arranged an arm 43 comprising an inner casing 44 housing a hydraulic cylinder 46. An extendable member in the form of a ram 48 projects from the hydraulic cylinder.

The ram 48 is secured at one end thereof to a bracket 50 fixed to and arranged within arm 43, and so causes the arm to extend from the outer casing 42 when operated.

Alternatively, a rack and pinion arrangement housed within the outer casing may be used to cause extension of the arm.

A further hydraulic actuator 52 is carried on the bracket 50 and incorporates an extendable rod 54 with a head 56 for pressing against cam 58 to cause the cam to pivot about pivot pin 60. A base 66 against which the cam 58 is able to clamp a metal strand as the strand is being trimmed from the strip and thereby cause the strand to be gripped, is carried below the end of the outer casing 42. A through passageway 62 is defined

between the base and the end of the outer casing 42 for enabling the trimmed strand to be received by the arm.

When metal strip 18 is being slit, the traversing clamp 20 is located generally at position A indicated in phantom outline in fig. 1 such that the through passageway 62 of each gripping device 26 is aligned with a scrap strand 70 being trimmed from the strip 18, respectively. With continued travel of the strip, each strand enters the passageway 62 of the corresponding arm 43. The hydraulic actuators 52 are then operated causing the cams 58 of the devices to pivot to a clamping position on extension of rods 54, and so clamp the scrap strands 70 against the bases 66 of the arms 43.

Once the scrap strands 70 are clamped, hydraulic actuators 30 are operated to cause the actuator arms 34 to be extended and hence the gripping devices 26 to be pivoted about their respective trunnions 28 so that the lower end region of the devices move outwardly away from the trimmed strip in opposite directions relative to one another. As will be appreciated, the pivoting of the gripping devices 26 also causes the scrap strands 70 to be pulled away from the opposite side edges of the trimmed metal strip 18 as the strip continues along its path of travel and enters gap 40 between the pinch rolls of the traversing clamp 20. Once received in the gap 40, the upper pinch roll 3 8 a is moved downwardly to thereby clamp the metal strip against the lower pinch roll 38b as described above.

The traversing clamp 20 is then moved in the direction of travel of the issuing strip 18. At the same time, the hydraulic cylinder 46 of each gripping device 26 is operated causing rams 48 to move and extend arms 43 so that the scrap strands 70 are drawn

down to receiving means in the form of scrap winders 72 located in the pit 22, one to each, with continued movement of the traversing clamp 20.

With further extension of the arms 43, the scrap strands 70 are pressed into the respective scrap winders 72 at which time the grip on the scrap strands 70 is released as the cams 58 return to resting positions with retraction of the rods 54 of hydraulic actuators 52 of the devices 26. When released, the scrap strands 70 are withdrawn from the gripping devices as the strands are taken up by rotation of the scrap winders 72 which proceed to coil the strands 70 as the trimmed metal strip 18 continues its travel across the pit while being supported by traversing clamp 20.

Having released the scrap strands 70, the rams 48 of the gripping devices are retracted into hydraulic cylinders 46 causing arms 43 to be retracted into their respective outer casings 42.

Once the traversing clamp has traversed the pit 22, the clamping of the trimmed metal strip 18 by the pinch rolls is released by movement of the upper pinch roll 38a away from the lower pinch roll 38b, enabling the trimmed strip to continue its passage between the pinch rolls to a conventional recoiler for recoiling the strip.

When the entire trimmed strip has passed through the traversing clamp 20, the gripping devices are returned to their initial positions by operation of the hydraulic actuators 52 as the traversing clamp is returned to position A indicated in fig. l for receiving the next trimmed strip as it issues from between the arbors 14 and 16 of the slitter head 12.

If desired, the arms 43 of the gripping devices 26 may be provided with telescopic inner casings 44 and rams 48 enabling the length of the gripping devices to be significantly shortened.

Accordingly, although the present invention has been described hereinbefore with reference to preferred embodiments, the skilled addressee will appreciate that numerous variations and modifications are possible without departing from the scope of the invention.