Registration control for a label cutoff apparatus

• US 4,384,500 A
• Filed: 11/20/1980
• Issued: 05/24/1983
• Est. Priority Date: 11/20/1980
• Status: Expired due to Term

• Current Assignee: Owens-Illinois Glass Container, Inc. (O-I Glass, Inc.)
• Original Assignee: Owens-Illinois Incorporated (O-I Glass, Inc.)
• Inventors: Friberg, Nelson
• Primary Examiner(s): Smith, James G.
• Assistant Examiner(s): Adolphson, K. Bradford
• Application Number:
  US06/208,712
• Time in Patent Office: 915 Days
• Field of Search: 83/72-76, 364/475
• US Class Current: 83/74
• CPC Class Codes: B26D 5/34 scanning being effected by a photosensitive device
• CPC Class Codes: Y10T 83/148 Including means to correct the sensed operation
• CPC Class Codes: Y10T 83/159 Including means to compensate tool speed for work-feed variations

Abstract

A registration control circuit for a printed label cutoff machine controls both the location of the cut by performing a phase adjustment and the length of the individual labels by performing a base speed adjustment. A strip of labels have eyemarks printed thereon for defining the location at which the individual labels are to be cut. An optical scanner is positioned adjacent the labels and generates a scanner pulse upon detection of an eyemark. The control circuit includes a setup control for automatically running the machine into registration from an initial setup position. The setup control functions to generate a reference pulse a predetermined distance before the scanner is expected to see an eyemark. When the eyemark is detected within a designated window area the control utilizes the scanner pulse and the reference pulse to calculate the phase error for each label and generate a phase correction signal proportional to the actual phase error. Individual phase error signals are combined to determine the average phase error which has occurred over the last predetermined number of labels. The average phase error is representative of an average base speed error. If the average phase error exceeds a predetermined threshold, the control will generate a base speed correction signal proportional to the average base speed error. When the eyemark is detected outside the designated window area, the control will attempt to bring the eyemark within the window area by performing a full speed phase adjustment. If, after a predetermined number of consecutive labels, the eyemark has not been moved within the window area, the control will check the base speed and perform a base speed adjustment. The control also includes an alphanumeric display for displaying to an operator, on a prioritized basis, messages indicating the operating status of the machine.

Claims

1. A control circuit for an apparatus for cutting individual segments from a moving strip of material, the apparatus having a cutting means, means for driving the cutting means, means for driving the strip of material, means for correlating the means for driving the cutting means with the means for driving the strip of material, means for generating a reference signal representing an actual position for each of a plurality of cuts, and means for generating a scan signal representing a desired position for each of the plurality of cuts, the control circuit comprising:

means responsive to the reference signal and the scan signal for generating a phase error signal representing the difference between the actual position and the desired position for an associated cut;

means responsive to said phase error signal for controlling the means for driving the strip of material to reduce said phase error signal for a subsequent cut;

means responsive to a predetermined number of said phase error signals exceeding a predetermined value for generating a base speed error signal representing the difference between an average actual length of the segments and a desired segment length; and

means responsive to said base speed error signal for controlling the means for correlating to reduce said base speed error signal.

2. The control circuit according to claim 1 wherein said means for generating a phase error signal generates said phase error signal proportional to the time elapsed between the generation of the reference signal and the generation of the scan signal.

3. The control circuit according to claim 1 including a source of clock pulses generated at a frequency proportional to the speed of the means for driving the cutting means and wherein said means for generating a phase error signal includes counter means responsive to the generation of the reference signal for counting said clock pulses and responsive to the generation of the scan signal for terminating said counting and means responsive to a count total of said counter means for generating said phase error signal.

4. The control circuit according to claim 3 wherein said counter means has a predetermined count range and said means responsive to said count total generates said phase error signal in proportion to the deviation of said count total from a midpoint of said predetermined count range.

5. The control circuit according to claim 1 wherein said means for generating a phase error signal generates a first error signal representing the magnitude of the phase error and a second error signal representing the direction of a correction to be made, and said means responsive to said phase error signal is responsive to said first and second error signals for controlling the means for correlating.

6. The control circuit according to claim 1 wherein the means for correlating includes a correction motor connected to the means for driving the strip of material, and means responsive to said phase error signal for actuating said correction motor to change the speed of the means for driving the strip of material with respect to the speed of the cutting means to reduce the phase error signal for the next cut.

7. The control circuit according to claim 6 wherein said phase error signal is proportional to the difference between the actual and desired positions for the cut and said means for actuating is responsive to said phase error signal for changing the speed of the means for driving the strip of material for a time proportional to said phase error signal.

8. The control circuit according to claim 6 wherein said phase error signal includes a signal representing the direction of the speed change and said means for actuating is responsive to said direction error signal for advancing and retarding the speed of the means for driving the strip of material.

9. The control circuit according to claim 1 wherein said means for generating a base speed error signal includes means responsive to two consecutive phase error signals for generating an average phase error signal, and means for comparing said average phase error signal with a predetermined maximum error signal for generating said base speed error signal.

10. The control circuit according to claim 1 wherein said means or generating a base speed error signal includes means responsive to a plurality of consecutive phase error signals for generating an average phase error signal, and means for comparing said average phase error signal with a predetermined maximum error signal for generating said base speed error signal.

11. In an apparatus for cutting individual labels from a moving strip of labels having a label cutting means, drive means for the cutting means and the strip of labels, means for generating a reference signal representing a position of the cutting means relative to an actual cut position, and means for generating a scan signal representing a position of each label relative to a desired cut position, a control circuit for the driving means comprising:

means responsive to the reference signal and the scan signal for generating a phase error signal representing the difference between the position of an actual cut and the position of a desired cut;

means responsive to each of said phase error signals for controlling the drive means to reduce said phase error signal for succeeding labels; and

means responsive to a predetermined number of consecutive phase error signals exceeding a predetermined value for controlling the drive means to change the speed of the strip of labels relative to the speed of cutting of the cutting means to reduce the phase error signals.

12. The control circuit according to claim 11 including a source of a cyclic signal having a frequency proportional to the frequency of cutting of the cutting means and wherein said means for generating a phase error signal includes counter means responsive to each of the reference signals for initiating counting of the cycles of said cylic signal and responsive to each of the scan signals for terminating said counting, and means responsive to a count total of said counter means for generating said phase error signals.

13. The control circuit according to claim 12 wherein said means responsive to said count total includes means for generating each of said phase error signals as a phase error magnitude signal representing the magnitude of the phase correction to be made and a phase error sign signal representing the direction of the phase correction to be made.

14. The control circuit according to claim 11 including a source of a cyclic signal having a frequency proportional to the frequency of cutting of the cutting means;

wherein said means for generating a phase error signal includes counter means responsive to each of the reference signals for initiating counting of the cycles of said cyclic signal and reponsive to each of the scan signals for terminating said counting, and means responsive to a count total of said counter means exceeding a predetermined value for generating a lost signal; and

including means responsive to said lost signal for controlling the drive means to reduce said phase error signal for the next cut.

15. The control circuit according to claim 14 including means responsive to said cyclic signal for generating a signal representing the speed at which the cuts are being made and wherein said means responsive to said count total is responsive to said speed signal for changing said predetermined value as a function of the speed at which the cuts are being made.

16. The control circuit according to claim 15 wherein said predetermined value is changed in direct proportion to the magnitude of the speed represented by said speed signal.

17. The control circuit according to claim 11 wherein said means for controlling the drive means to change the speed includes means responsive to two consecutive ones of said phase error signals for generating an average signal having a magnitude representing the average of the differences, means for generating an error signal when the magnitude of said average signal exceeds a predetermined value, and means responsive to said error signal for changing the speed of the strip of labels relative to the speed of cutting by the cutting means in proportion to the magnitude of said average signal.

18. The control circuit according to claim 11 wherein said means for controlling the drive means to change the speed includes means responsive to a plurality of consecutive phase error signals for generating an average signal having a magnitude representing the average of the differences, means for generating an error signal when the magnitude of said average signal exceeds a predetermined value, and means responsive to said error signal for changing the speed of the strip of labels relative to the speed of cutting by the cutting means in proportion to the magnitude of said average signal.

19. The control circuit according to claim 18 wherein said plurality of consecutive phase error signals is twelve.

20. The control circuit according to claim 11 wherein said means for controlling the drive means to change the speed changes the speed at a predetermined maximum rate.

21. The control circuit according to claim 11 wherein said predetermined number is thirty-two.

22. The control circuit according to claim 11 including means responsive to said phase error signals for displaying messages representing the status of the control circuit.

23. A control circuit for an apparatus for cutting individual segments from a moving strip of material, the apparatus having a cutting means, means for driving the cutting means and the strip of material, means for generating a scan signal representing a desired cut position for a plurality of segments, means for generating a reference signal representing an actual cut position for the plurality of segments, and means for generating a cyclic signal, each cycle representing a predetermined increment of distance between actual cuts, the control circuit comprising:

first means for counting the cycles of the cyclic signal responsive to a first one of the scan signals for initiating counting and responsive to a first one of the reference signals for terminating counting;

second means for counting the cycles of the cyclic signal responsive to the reference signals for initiating counting from a count total of said first means for counting and for generating a new reference signal at a predetermined count total; and

means responsive to the scan signals and said new reference signals for maintaining the cutting means and the strip of material in registry.

24. The control circuit according to claim 23 including means for presetting said first means for counting with a predetermined initial count total.

25. The control circuit according to claim 24 wherein said predetermined initial count total represents one half of the number of cycles of the cyclic signal representing a window during which one of the scan signals should be generated.

26. The control circuit according to claim 23 including means responsive to said first counting means count total for generating a visual indication of the position of said new reference signals with respect to the position of said new reference signal generated from said first scan and first reference signals.

27. The control circuit according to claim 26 including means for selectively changing said count total of said first means for counting.

28. A control circuit for an apparatus for cutting individual segments from a moving strip of material, the apparatus having a cutting means, means for driving the cutting means and the strip of material, means for generating a reference signal representing an actual position for a plurality of cuts, and means for generating a scan signal representing a desired position for the plurality of cuts, the control circuit comprising:

means responsive to said reference signals and said scan signals for generating a phase error signal for each of the cuts representing the difference between the actual position and the desired position for the associated cut;

means responsive to said phase error signals for comparing each of said phase error signals with a window representing a predetermined range of phase error signal differences and generating a lost signal when one of said phase error signals is outside said window; and

means responsive to a predetermined number of said lost signals for controlling the drive means to reduce said phase error signal differences.

29. The control circuit according to claim 28 wherein said predetermined number of lost signals is thirty-two.

30. The control circuit according to claim 28 wherein said means for controlling changes the speed of the strip of material relative to the speed of cutting of the cutting means to reduce said phase error signal differences.

31. The control circuit according to claim 30 wherein said means for controlling changes the speed of the strip of material relative to the speed of cutting of the cutting means at a predetermined rate.

32. A control circuit for an apparatus for cutting individual segments from a moving strip of material, the apparatus having a cutting means, means for driving the cutting means and the strip of material, means for generating a reference signal representing an actual position for each of a plurality of cuts, and means for generating a scan signal representing a desired position for each of the plurality of cuts, the control circuit comprising:

means responsive to the reference signal and the scan signal for generating a phase error signal for the segments representing the difference between the actual position and the desired position for the cut associated with the segment;

means responsive to said phase error signal for controlling the drive means to reduce said phase error signal for subsequent segments;

means responsive to a predetermined number of said phase error signals exceeding a predetermined value for generating a base speed error signal representing the difference between an average actual length of the segments and a desired segment length; and

means responsive to said base speed error signal for controlling the means for driving to reduce said base speed error signal.

33. The control circuit according to claim 32 wherein the means for driving includes a drive motor connected to the cutting means and to a feed roll means for moving the strip of material.

34. The control circuit according to claim 33 wherein the means for driving includes a variable ratio transmission means connected between said drive motor and said feed roll means.

35. The control circuit according to claim 34 wherein the means for driving includes a correction motor connected to said transmission means, and means responsive to said phase error signal for actuating said correction motor to change the speed of said feed roll means with respect to the speed of the cutting means to reduce the phase error for a subsequent cut.

36. The control circuit according to claim 34 wherein the means for driving includes a stepping motor connected to said transmission means, and said means for controlling the means for driving is responsive to said base speed error signal for actuating said stepping motor to change the speed of said feed roll means with respect to the speed of the cutting means to reduce said base speed error signal.