MACHINE COMBINATION

Abstract: There is disclosed the combination of upstream and downstream machines for processing discrete workpieces, each machine comprising rollers forming a nip through which the successive workpieces pass, the rollers of the two machines operating with equal angular velocity but being of different diameter and a conveyor for carrying the successive workpieces from the upstream machine to the downstream machine and arranged to deliver the leading edge of each workpiece to the dowstream machine at a linear velocity equal to the peripheral velocity of the rollers of the downstream machine.

Description: MACHINE COMBINATION This invention concerns a combination of upstream and downstream machines for processing a succession of discrete workpieces, each machine comprising rollers forming a nip through which the workpieces pass and operating at the same angular velocity to ensure that the successive processing operations are in register. Typically, though by no means exclusively, the machines might be in a line of machinery for manufacturing cases from corrugated paper board. Hitherto, the rollers of the two machines have needed to be of the same diameter - so that their peripheral speeds are identical enabling direct feed of the workpieces from one machine to the other. This has imposed serious restrictions on the freedom of choice for additional or replacement machines in an existing line of machinery. It is an object of the present invention to provide a machine combination which overcomes the problem aforesaid. According to the present invention there is provided the combination of upstream and downstream machines for processing discrete workpieces, each machine comprising rollers forming a nip through which the successive workpieces pass, the rollers of the two machines operating with equal angular velocity but being of different diameter and a conveyor for carrying the successive workpieces from the upstream machine to the downstream machine and arranged to deliver the leading edge of each workpiece to the downstream machine at a linear velocity equal to the peripheral velocity of the rollers of the downstream machine. The conveyor may comprise an endless band encircling forward and rearward guide rollers. The band may be perforate and its upper run may extend over a vacuum chamber whereby suction holds the workpieces against the band to travel with the band at the same speed as the band. The band may have a linear velocity equal to the peripheral velocity of the rollers of the downstream machine. The band may be driven by a servo-motor controlled to vary its speed during transfer of each workpiece. The workpieces may be rectangular blanks of corrugated paper board. The downstream machine may be a rotary die-cutter. The upstream machine may be a printer-slotter. The invention will be further apparent from the following description with reference to the single figure of the accompanying drawing, which shows, by way of example only, one form of combination embodying same. Referring now to the drawing, it will be seen that there is an upstream processing machine 10 and a downstream processing machine 11, in this example a printer-slotter and a rotary die-cutter respectively. The machines 10 and 11 process a succession of discrete workpieces, in this example rectangular blanks of corrugated paper board. The machine 10 has rollers 12 forming a nip through which the successive workpieces pass and the machine 11 has rollers 13 forming a nip through which successive workpieces part. The angular velocity of the rollers 12 and 13 is necessarily identical - to ensure that the successive processing operations are in register, but are of different diameters. Necessarily, then, the peripheral velocities of the rollers 12 and 13 are different. The combination of the invention includes a transfer conveyor generally indicated at 15 to carry boards from the printer-slotter 10 to the rotary die-cutter 11. The conveyor 15 comprises an endless band 16 encircling forward and rearward guide rollers 17 and 18 respectively. The band 16 is perforate and its upper run extends over a vacuum chamber 19 whereby suction holds the workpieces being conveyed against the band to travel with the band at the same speed as the band. The conveyor 15 is arranged to deliver the leading edge of each blank to the rotary die-cutter 11 at a linear speed equal to the peripheral speed of the rollers 13. In one embodiment, then, the linear speed of the band 16 is constant and matches the peripheral speed of the rollers 13. In another embodiment, the band 16 is driven by a servo-motor 20 controlled to vary the linear speed of the band during transfer of each blank either upwardly or downwardly to deliver its leading edge to the die-cutter 11 at the correct velocity. The servo-motor is controlled by a micro-processor 21. It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible, without departing from the scope thereof as defined by the appended claims.

Claims: CLAIMS 1. The combination of upstream and downstream machines for processing discrete workpieces, each machine comprising rollers forming a nip through which the successive workpieces pass, the rollers of the two machines operating with equal angular velocity but being of different diameter and a conveyor for carrying the successive workpieces from the upstream machine to the downstream machine and arranged to deliver the leading edge of each workpiece to the downstream machine at a linear velocity equal to the peripheral velocity of the rollers of the downstream machine. 2. The combination of claim 1 wherein the conveyor comprises an endless band encircling forward and rearward guide rollers. 3. The combination of claim 2 wherein the band is perforate and its upper run extends over a vacuum chamber whereby suction holds the workpieces against the band to travel with the band at the same speed as the band. 4. The combination of claim 2 and claim 3 wherein the band has a linear velocity equal to the peripheral velocity of the rollers of the downstream machine. 5. The combination of claim 2 or claim 3 wherein the band is driven by a servo-motor controlled to vary its speed during transfer of each workpiece. 6. The combination of any preceding claim wherein the workpieces are rectangular blanks of corrugated paper board. 7. The combination of claim 6 wherein the downstream machine is a rotary die-cutter. 8. The combination of claim 6 and claim 7 wherein the upstream machine is a printer-slotter.

Inventors: SULLIVAN JOHN ANTHONY, SULLIVAN, JOHN, ANTHONY
Applicants: SULLIVAN JOHN ANTHONY, SULLIVAN, JOHN, ANTHONY
Application year: 2000
Main classification: B21B39
IPC codes: B21B39, B31B1, B31F1, B65G15, B65H5