Apparatus and method for ensuring proper machining of a worksheet

• US 5,485,391 A
• Filed: 03/23/1994
• Issued: 01/16/1996
• Est. Priority Date: 10/10/1991
• Status: Expired due to Term

• Current Assignee: Finn-Power International Incorporated
• Original Assignee: Finn-Power International Incorporated
• Inventors: Lindstrom, Mikko
• Primary Examiner(s): Trammell, James P.
• Application Number:
  US08/216,364
• Time in Patent Office: 664 Days
• Field of Search: 364/474.16-474.21, 318/561, 483/1, 483/29, 72/446, 72/448, 72/442, 83/698.91, 83/620
• US Class Current: 700/175
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition
• CPC Class Codes: G05B 2219/36347 Select tool if tool life duration is sufficient for operation
• CPC Class Codes: G05B 2219/37252 Life of tool, service life, decay, wear estimation
• CPC Class Codes: G05B 2219/50276 Detect wear or defect tool, breakage and change tool

Abstract

To ensure that a worksheet is effectively operated on, the present invention system monitors the life expectancy of a tool by counting the number of hits the tool has made so that when it is reached, the tool is replaced by a spare tool. Alternatively or in combination therewith, in place of monitoring the life expectancy of the tool, the operational effectiveness of the tool is monitored. Thus, anytime that the operational effectiveness of the tool is deemed to fall below a given standard, the tool is replaced by a spare tool. The replacing of the tool by a spare, and the subsequent replacement of the spare tool by yet another spare can go on ad infinitum. With such a system, severe failure of tools are prevented.

Claims

1. A work station having a worktable onto which worksheets to be worked on are placed, a first tool means positioned in proximate relation to said work station for performing work on successive ones of said worksheets at a work location, apparatus for ensuring each one of said worksheets is not worked on by an operationally ineffective tool means, comprising:

at least one additional tool means positioned relative to said work station and movable to said work location for replacing said first tool means;

means for generating hit signals to operate said first tool means;

means for counting each hit signal output from said hit signal generating means;

means associated with said work station for automatically replacing said first tool means with said additional tool means at said work location when the number of hit signals output from said hit signal generating means to operate said first tool means, as counted by said counting means, reaches a predetermined number.

2. The work station of claim 1, wherein said counting means comprises:

a first register means set to a predetermined count;

a second register means adaptable to count said each hit signal; and

wherein said work station further comprising;

means for comparing the count in said second register means against said predetermined count in said first register means, said replacing means replacing said first tool means with said additional tool means when the count in said second register means at least equals to said predetermined count in said first register means.

3. The work station of claim 1, further comprising:

at least another additional tool means positioned relative to said work table, said first tool means, additional tool means and another additional tool means all being interchangeable so that said worksheet can be effectively worked on by any one of said tool means.

4. The work station of claim 1, further comprising:

a plurality of tool means at least one of which being interchangeable with said first tool means;

wherein said counting means comprises;

first register means having different predetermined count limits each set for a corresponding one of said plurality of tool means, said first register means further having a first predetermined count limit for said first tool means;

second register means having a plurality of counter means each for counting the number of times a hit signal is generated for a corresponding one of said plurality of tool means, said second register means having a first counter means for counting the number of times hit signals are generated to operate said first tool means;

wherein when said first counter means has a count that at least equals to said first predetermined count limit, said replacing means proceeds to replace said first tool means with an interchangeable tool means from said plurality of tool means whose corresponding second register means does not register a count that equals to its corresponding count limit set in said first register means.

5. The station of claim 1, further comprising:

means for instructing said generating means to output a specific number of hit signals, each of said hit signals effecting said first tool means to operate once.

6. The station of claim 1, further comprising:

means for monitoring the movement of said first tool means when it operates, said movement being provided as a signal to said counting means.

7. The station of claim 1, further comprising:

means for driving said first tool means to perform work on said worksheet, said driving means being activated to drive said first tool means once each time it receives a hit signal from said generating means.

8. The work station of claim 1, further comprising:

means for sending a signal to effect said first tool means to be driven a given distance;

means for measuring the distance of movement of said first tool means; and

means for comparing said signal and said measured movement distance, the compared result being provided to said counting means as a tool operation if there is a correspondence between said signal and said measured movement distance.

9. The work station of claim 8, wherein said sending means comprises:

means programmable to effect different tools to be driven different distances.

10. A work station having a worktable onto which a worksheet to be worked on is placed, gripper means for positioning said worksheet on said worktable, a turret positioned relative to said worktable, a first tool means rotatably mounted on said turret and positioned at a work position of said work station for performing work on said worksheet, apparatus for ensuring said worksheet is effectively worked, comprising:

at least a second tool means rotatably mounted on said turret and positionable to said work position of said work station to perform work on said worksheet;

means for ascertaining, on a non-time dependent tool wear basis, whether said first tool means is effective for performing work on said worksheet;

means for replacing said first tool means with said second tool means by rotating said turret to position said first tool means away from said work position and said second tool means to said work position when said ascertaining means determines said first tool means to be no longer effective for performing work on said worksheet.

11. The work station of claim 10, further comprising:

a plurality of tool means including said first and second tool means rotatably mounted on said turret, at least one of said plurality of tool means being interchangeable with said first and second tool means for performing work on said worksheet;

wherein said ascertaining means utilizes a determination of whether the quality of an operation effected on said worksheet is above a preset quality due to tool wear for determining the operational effectiveness of the tool means that effected said operation on said worksheet; and

wherein said replacing means replaces said tool means that effected said operation on said worksheet with an interchangeable tool means from said plurality of tool means if the quality of said operation is determined to be below said preset quality.

12. The work station of claim 11, wherein said plurality of tool means comprises punches of different sizes, only punches of substantially the same size being interchangeable.

13. A numerically controlled machining center having at least one work station, a worktable onto which successive ones of worksheets for movement with respect to said work station are placed, moving means associated with said worktable for presenting each successive one of said worksheets to said work station, a plurality of tool means positioned relative to said work station each adaptable for performing work on each of said worksheets, one of said plurality of tool means selected to perform work on said each worksheet at a work location, comprising:

means for generating signals for operating said one tool means;

means for keeping a count of the number of said signals generated by said generating means to operate said one tool means;

means for replacing said one tool means with another tool means from said plurality of tool means for performing work at said work location when the kept count for said one tool means reaches a predetermined number.

14. The center of claim 13, wherein said keeping means comprises:

a first register means having multiple predetermined count numbers each assigned to a corresponding one of said plurality of tool means;

a second register means for respectively counting the number of times corresponding hit signals are generated for each of said plurality of tool means;

wherein when the count number in said second register means for any tool means selected to perform work on said worksheet at least equals to the assigned predetermined count number in said first register means for said any tool means, said replacing means replaces said any tool means with a tool means from said plurality of tool means that is interchangeable with said any tool means and whose count number in said second register means is less than its corresponding assigned predetermined count number in said first register means.

15. The center of claim 13, wherein said plurality of tool means comprises punches.

16. The center of claim 13, further comprising:

means for instructing said generating means to output a specific number of hit signals, each of said hit signals effecting said one tool means to perform work once.

17. The center of claim 13, further comprising:

means for monitoring the movement of said one tool means each time it performs work, said movement being provided as a signal to be recorded by said recording means.

18. The station of claim 13, further comprising:

means for driving said one tool means to perform work on said each worksheet, said driving means being activated to singly drive said one tool means to perform work on said each worksheet each time it receives a hit signal from said generating means.

19. The center of claim 13, further comprising:

means for sending a signal to effect said one tool means to be driven a given distance;

means for measuring the distance of movement of said one tool means; and

means for comparing said signal and said measured movement distance, the compared result being provided to said keeping means as a tool operation if there is a correspondence between said signal and said measured movement distance.

20. The center of claim 19, wherein said sending means comprises:

means programmable to effect different tools to be driven different distances.

21. A numerically controlled machining center having at least one work station, a worktable onto which a worksheet for movement with respect to said work station is placed, moving means associated with said worktable for presenting said worksheet to said work station, a turret, a plurality of tool means each rotatably mounted on said turret and positionable to a work position relative to said work station, each of said tool means adaptable for performing work on said worksheet, one of said plurality of tool means selected to perform work on said worksheet, comprising:

means positioned proximately to said worktable for monitoring the operational effectiveness of said selected tool means performing work on said worksheet, said operational effectiveness being based on the amount of wear of said selected tool means;

means for replacing said selected tool means with another tool means by rotating said turret to position said selected tool means away from said work position and said another tool means to said work position when said monitoring means determines said selected tool means to be ineffective for performing work on said worksheet.

22. The work station of claim 21, further comprising:

a plurality of tool means including said selected and another tool means, at least one of said plurality of tool means being interchangeable with said selected and another tool means for performing work on said worksheet;

wherein said monitoring means utilizes the quality of the operation effected on said worksheet for determining the operational effectiveness of said selected tool means; and

wherein said replacing means replaces said selected tool means with said another tool means from said plurality of tool means if the quality of said operation is determined to be below a preset quality.

23. A numerically controlled machining center having at least one work station, a worktable onto which a worksheet for movement with respect to said work station is placed, moving means associated with said worktable for presenting said worksheet to said work station, a plurality of tool means positioned relative to said work station each adaptable for performing work on said worksheet, one of said plurality of tool means selected to perform work on said worksheet, comprising:

means for recording at least a count of the number of times said one tool means performs work;

means positioned proximately to said work table for monitoring the operational effectiveness of said one tool means;

means for replacing said one tool means with another tool means from said plurality of tool means when either the recorded count for said one tool means reaches a predetermined number or said monitoring means determines said one tool means to be operationally ineffective.

24. The center of claim 23, wherein said recording means comprises:

a first register means having multiple predetermined count numbers each assigned to a corresponding one of said plurality of tool means;

a second register means for respectively counting the number of times each of said plurality of tool means performs work;

wherein said replacing means replaces said one tool means with said another tool means when the count number for said one tool means in said second register means at least equals to the corresponding predetermined count number assigned thereto in first register means.

25. The center of claim 23, wherein said recording means comprises:

a first register means having different predetermined count numbers each assigned to a corresponding one of said plurality of tool means;

a second register means for respectively counting the number of times each of said plurality of tool means performs work;

wherein when the count number for any tool means in said second register means at least equals to the assigned predetermined count number in said first register means for said any tool means, said replacing means replaces said any tool means with a tool means from said plurality of tool means that is interchangeable with said any tool means and whose count number in said second register means is less than its corresponding assigned predetermined count number in said first register means.

26. The center of claim 23, wherein said monitoring means comprises:

means for determining the quality of the work performed on said worksheet by said one tool means;

means for comparing the determined quality with a preset quality to ascertain the operational effectiveness of said one tool means;

wherein said replacing means replaces said one tool means with said another tool means if the determined quality is below said preset quality.

27. The center of claim 23, further comprising:

means for generating hit signals each corresponding to each time said one tool means performs work;

counter means for sensing each of said generated hit signals, each of said sensed hit signals being provided as individual counts to said recording means.

28. The center of claim 27, further comprising:

means for instructing said generating means to output a specific number of hit signals, each of said hit signals effecting said one tool means to perform work once.

29. The center of claim 27, further comprising:

means for driving said one tool means to perform work on said worksheet, said driving means being activated to drive said one tool means once each time it receives a hit signal from said generating means.

30. The center of claim 23, further comprising:

means for monitoring the movement of said one tool means each time it performs work, said movement being provided as a signal to be recorded by said recording means.

31. The center of claim 23, further comprising:

means for sending a signal to effect said one tool means to be driven a given distance;

means for measuring the distance of movement of said one tool means; and

means for comparing said signal and said measured movement distance, the compared result being provided to said recording means as a tool operation if there is a correspondence between said signal and said measured movement distance.

32. The center of claim 31, wherein said sending means comprises:

means programmable to effect different tools to be driven different distances.

33. In a numerically controlled machining center having at least one work station, a worktable onto which successive ones of worksheets for movement with respect to said work station are placed, moving means associated with said worktable for presenting each successive ones of said worksheets to said work station, a first tool means positioned relative to said work station for performing work on said each successive worksheet at a work location, a method of ensuring said worksheet is not worked on by an operationally ineffective tool means, comprising the steps of:

positioning at least one spare tool means relative to said work station;

counting the number of times signals are output by a signal generating means to operate said first tool means;

replacing said first tool means with said spare tool means at said work location when the counted number of times signals are output to operate said first tool means reaches a predetermined number.

34. The method of claim 33, wherein said counting step comprises the steps of:

setting a predetermined count number for said first tool means;

comparing the counted number of times signals are output by said signal generating means to said first tool means with said predetermined count number; and

said method further comprising the step of;

initializing a means for performing said replacing step when said counted number at least equals said predetermined count number.

35. The method of claim 33, further comprising the step of:

providing instructions to said signal generating means to output a specific number of hit signals, each of said hit signals effecting said first tool means to operate once.

36. The method of claim 33, further comprising the steps of:

monitoring the movement of said first tool means when it operates; and

providing said movement as a signal to be counted in said counting step.

37. The method of claim 33, further comprising the step of:

utilizing each of said generated signals to singly operate said first tool means to perform work on said each worksheet.

38. The method of claim 33, further comprising the steps of:

sending a signal to effect said first tool means to be driven a given distance;

measuring the distance of movement of said one tool means; and

comparing said signal and said measured movement distance, the compared result being instrumental in causing said first tool means to be replaced by said spare tool means if there is a correspondence between said signal and said measured movement distance.

39. In a numerically controlled machining center having at least one work station, a worktable onto which a worksheet for movement with respect to said work station is placed, moving means associated with said worktable for presenting said worksheet to said work station, a turret rotatably positioned relative to said worktable, a first tool means rotatably mounted to said turret and positioned relative to a work position of said work station for performing work on said worksheet, a method of ensuring said worksheet is not worked on by an operationally ineffective tool means, comprising the steps of:

rotatably mounting at least one spare tool means to said turret;

monitoring the operational effectiveness of said first tool means to perform work on said worksheet;

correlating said operational effectiveness with the amount of wear of said first tool means;

replacing said first tool means with said spare tool mean by rotating said turret to position said first tool means away from said work position and said spare tool means to said work position when said first tool means is determined to be ineffective for performing work on said worksheet.

40. The method of claim 39, wherein said monitoring step comprises the step of:

sensing the quality of the operation effected on said worksheet by said first tool means to determine the operational effectiveness of said first tool means; and

wherein said replacing step comprises the step of;

comparing the sensed quality of operation with a preset quality to ascertain the operational effectiveness of said first tool means, said first tool means ascertained to be operationally ineffective if said sensed quality is below said preset quality.

41. In a numerically controlled machining center having at least one work station, a worktable onto which a worksheet for movement with respect to said work station is placed, moving means associated with said worktable for presenting said worksheet to said work station, a plurality of tool means positioned relative to said work station each adaptable for performing work on said worksheet, a method of ensuring said worksheet is effectively worked on, comprising the steps of:

(a) selecting one tool means from said plurality of tool means to perform work on said worksheet;

(b) recording at least a count of the number of times said selected tool means performs work;

(c) monitoring the operational effectiveness of said selected tool means;

(d) selecting another tool means from said plurality of tool means interchangeable with said selected tool means to replace said selected tool means if the recorded count for said selected tool means reaches a predetermined number or said selected tool means is determined to be operationally ineffective;

(e) repeating steps (b) to (d) for each selected tool means.

42. The method of claim 41, wherein said step (b) further comprises the steps of:

assigning respective predetermined count numbers to corresponding ones of said plurality of tool means;

counting the respective number of times each of said plurality of tool means performs work; and

wherein said step (d) comprises the step of;

replacing said selected tool means with said another selected tool means when the counted number for said selected tool means having perform work at least equals to the corresponding predetermined count number assigned thereto.

43. The method of claim 42, wherein said step (c) further comprises the steps of:

determining the quality of the work performed on said worksheet by said selected tool means;

comparing the determined quality with a preset quality to ascertain the operational effectiveness of said selected tool means; and

wherein said step (d) further comprises the step of;

replacing said selected tool means with said another selected tool means if the determined quality is below said preset quality.

44. The method of claim 41, further comprising the steps of:

(f) generating hit signals each corresponding to each time said selected tool means performs work;

(f) sensing each of said generated hit signals, each of said sensed hit signals being provided as individual counts to be recorded in said recording step.

45. The method of claim 44, further comprising the step of:

(g) instructing said generating means to output a specific number of hit signals, each of said hit signals effecting said selected tool means to perform work once.

46. The method of claim 44, further comprising the step of:

(j) utilizing each of said generated hit signals to singly drive said selected tool means to perform work on said worksheet.

47. The method of claim 41, further comprising the steps of:

(h) monitoring the movement of said selected tool means each time it performs work; and

(i) providing the movement as a signal to be recorded in said recording step.

48. The method of claim 41, further comprising the steps of:

(k) sending a signal to effect said selected tool means to be driven a given distance;

(1) measuring the distance of movement of said selected tool means; and

(m) comparing said signal and said measured movement distance, the compared result being provided to said recording step to be counted if there is a correspondence between said signal and said measured movement distance.