Shredder thickness with anti-jitter feature

• US 8,464,767 B2
• Filed: 01/27/2012
• Issued: 06/18/2013
• Est. Priority Date: 10/04/2007
• Status: Expired due to Fees

• Current Assignee: Fellowes Incorporated
• Original Assignee: Fellowes Incorporated
• Inventors: Matlin, Tai Hoon K., Jensen, Michael Dale
• Primary Examiner(s): MILLER, BENA B
• Application Number:
  US13/360,198
• Publication Number:
  US 20120119005A1
• Time in Patent Office: 508 Days
• Field of Search: 241/33, 241/34, 241/36, 241/37.5, 241/100, 241/236
• US Class Current: 144/36
• CPC Class Codes: B02C 18/0007 specially adapted for disintegrating documents
• CPC Class Codes: B02C 18/16 Details
• CPC Class Codes: B02C 2018/0038 Motor drives
• CPC Class Codes: B02C 2018/164 Prevention of jamming and/or overload
• CPC Class Codes: B02C 25/00 Control arrangements specially adapted for crushing or disintegrating

Abstract

A shredder includes a housing having a throat for receiving at least one article to be shredded, and a shredder mechanism having a motor and cutter elements. The shredder also includes a detector that is configured to detect a thickness of the at least one article being received by the throat, and a controller that is configured to operate the motor to drive the cutter elements to shred the at least one article and to set a flutter threshold higher than the predetermined maximum thickness threshold, if the detected thickness is less than a predetermined maximum thickness threshold. The controller is also configured to thereafter continuously detect the thickness of the at least one article being inserted into a throat of the shredder; and to perform a predetermined operation responsive to the thickness detector detecting that the thickness of the at least one article is greater than the flutter threshold.

Claims

1. A shredder comprising:

a housing having a throat for receiving at least one article to be shredded;

a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article to be shredded to be fed into the cutter elements and the motor being operable in a shredding direction to drive the cutter elements to shred the articles fed therein;

at least one thickness detector configured to detect a thickness of the at least one article to be shredded being received by the throat; and

a controller coupled to the motor and the at least one thickness detector for receiving an input from the at least one thickness detector,

wherein, when the at least one article is being received by the throat prior to operation of the motor, the controller either (a) operates the motor in the shredding direction to drive the cutter elements to shred the at least one article being received by the throat if the at least one thickness detector detects that the at least one article is below a predetermined maximum thickness threshold, or (b) prevents operation of the motor in the shredding direction if the at least one thickness detector detects that the at least one article to be shredded being received by the throat is violating the predetermined maximum thickness threshold,

wherein the controller monitors the input from the at least one thickness detector during operation of the motor in the shredding direction to shred the at least one article to determine whether the input from the at least one thickness detector detecting a violation of the predetermined maximum thickness threshold meets at least one criterion corresponding to an insertion of one or more additional articles, said controller performing a predetermined operation in response to determining that the at least one criterion has been met.

2. A shredder according to claim 1, wherein the controller monitors a characteristic of the input from the at least one thickness detector during operation of the motor in the shredding direction to shred the at least one article to determine whether the at least one criterion corresponding to an insertion of one or more additional articles has been met.

3. A shredder according to claim 2, wherein the controller monitors a rate at which the detected thickness changes as the characteristic of the input from the at least one thickness detector, and wherein the at least one criterion includes the rate being above a predetermined rate threshold.

4. A shredder according to claim 1, wherein said controller monitors the input from the at least one thickness detector by filtering the input to determine whether the at least one criterion corresponding to an insertion of one or more additional articles has been met.

5. A shredder according to claim 1, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

6. A shredder according to claim 2, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

7. A shredder according to claim 4, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

8. A shredder according to claim 1, wherein the at least one thickness detector comprises a variable thickness detector for detecting and outputting varying amounts of detected thicknesses as the input to the controller.

9. A shredder according to claim 2, wherein the at least one thickness detector comprises a variable thickness detector for detecting and outputting varying amounts of detected thicknesses as the input to the controller.

10. A shredder according to claim 3, wherein the at least one thickness detector comprises a variable thickness detector for detecting and outputting varying amounts of detected thicknesses as the input to the controller.

11. A shredder according to claim 8, wherein said variable thickness detector includes a contact member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

12. A shredder according to claim 11, wherein said sensor is an optical sensor.

13. A shredder according to claim 1, wherein the controller is also configured to monitor a motor operating condition during the operation of the motor in the shredding direction to determine whether to prevent operation of the motor in the shredding direction.

14. A shredder according to claim 1, wherein the at least one thickness detector comprises a binary thickness detector.

30. A shredder according to claim 1, wherein the at least one thickness detector is a single thickness detector.

31. A shredder according to claim 30, wherein the single thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thickness as the input to the controller.

32. A shredder according to claim 31, wherein said variable thickness detector includes a control member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

33. A shredder according to claim 32, wherein said sensor is an optical sensor.

15. A shredder comprising:

a housing having a throat for receiving at least one article to be shredded;

a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article to be shredded to be fed into the cutter elements and the motor being operable in a shredding direction to drive the cutter elements to shred the articles fed therein;

at least one thickness detector configured to detect a thickness of the at least one article to be shredded being received by the throat; and

a controller coupled to the motor and the at least one thickness detector for receiving an input from the at least one thickness detector,

wherein, when the at least one article is being received by the throat prior to operation of the motor the controller either (a) operates the motor in the shredding direction to drive the cutter elements to shred the at least one article being received by the throat if the at least one thickness detector detects that the at least one article is below a predetermined maximum thickness threshold, or (b) prevents operation of the motor if the at least one thickness detector detects that the at least one article to be shredded being received by the throat is violating the predetermined maximum thickness threshold,

wherein the controller filters the input from the at least one thickness detector during operation of the motor in the shredding direction to shred the at least one article to determine whether the input from the at least one thickness detector detecting a violation of the predetermined maximum thickness threshold meets at least one criterion corresponding to an insertion of one or more additional articles, said controller performing a predetermined operation in response to determining that the at least one criterion has been met.

16. A shredder according to claim 15, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

17. A shredder according to claim 16, wherein the predetermined operation further comprises actuating an indicator to alert a user.

18. A shredder according to claim 15, wherein the at least one thickness detector comprises a variable thickness detector for detecting and outputting varying amounts of detected thicknesses as the input to the controller.

19. A shredder according to claim 18, wherein said variable thickness detector includes a contact member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

20. A shredder according to claim 19, wherein said sensor is an optical sensor.

21. A shredder according to claim 15, wherein the controller is also configured to monitor a motor operating condition during the operation of the motor in the shredding direction to determine whether to prevent operation of the motor in the shredding direction.

22. A shredder according to claim 16, wherein the at least one thickness detector comprises a binary thickness detector.

34. A shredder according to claim 15, wherein the at least one thickness detector is a single thickness detector.

35. A shredder according to claim 34, wherein the single thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thickness as the input to the controller.

36. A shredder according to claim 35, wherein said variable thickness detector includes a control member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

37. A shredder according to claim 36, wherein said sensor is an optical sensor.

23. A shredder comprising:

a housing having a throat for receiving at least one article to be shredded;

a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article to be shredded to be fed into the cutter elements and the motor being operable in a shredding direction to drive the cutter elements to shred the articles fed therein;

at least one thickness detector configured to detect a thickness of the at least one article to be shredded being received by the throat; and

a controller coupled to the motor and the at least one thickness detector for receiving an input from the at least one thickness detector,

wherein the controller monitors the input during operation of the motor in the shredding direction to shred the at least one article to determine whether the input from the at least one thickness detector detecting a violation of a predetermined maximum thickness threshold meets at least one criterion corresponding to an insertion of one or more additional articles, the controller performing a predetermined operation in response to determining that the at least one criterion has been met.

24. A shredder according to claim 23, wherein the controller is monitors a characteristic of the input from the at least one thickness detector during operation of the motor in the shredding direction to shred the at least one article to determine whether the at least one criterion corresponding to an insertion of one or more additional articles has been met.

25. A shredder according to claim 24, wherein the controller monitors a rate at which the detected thickness changes as the characteristic of the input from the at least one thickness detector, and wherein the at least one criterion includes the rate being above a predetermined rate threshold.

26. A shredder according to claim 23, wherein said controller monitors the input from the at least one thickness detector by filtering the input to determine whether the at least one criterion corresponding to an insertion of one or more additional articles has been met.

27. A shredder according to claim 23, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

38. A shredder according to claim 23, wherein the at least one thickness detector is a single thickness detector.

39. A shredder according to claim 38, wherein the single thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thickness as the input to the controller.

40. A shredder according to claim 39, wherein said variable thickness detector includes a control member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

41. A shredder according to claim 40, wherein said sensor is an optical sensor.

28. A shredder comprising:

a housing having a throat for receiving at least one article to be shredded;

a shredder mechanism received in the housing and including an electrically powered motor and cutter elements, the shredder mechanism enabling the at least one article to be shredded to be fed into the cutter elements and the motor being operable in a shredding direction to drive the cutter elements to shred the articles fed therein;

at least one thickness detector configured to detect a thickness of the at least one article to be shredded being received by the throat; and

a controller coupled to the motor and the at least one thickness detector for receiving an input from the at least one thickness detector,

wherein the controller filters the input during operation of the motor in the shredding direction to shred the at least one article to determine whether the input from the at least one thickness detector detecting a violation of a predetermined maximum thickness threshold meets at least one criterion corresponding to an insertion of one or more additional articles, said controller performing a predetermined operation in response to determining that the at least one criterion has been met.

29. A shredder according to claim 28, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction.

42. A shredder according to claim 28, wherein the at least one thickness detector is a single thickness detector.

43. A shredder according to claim 42, wherein the single thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thickness as the input to the controller.

44. A shredder according to claim 43, wherein said variable thickness detector includes a control member in the throat movable by engagement of the article being received in the throat, and a sensor for measuring an amount of displacement of the contact member.

45. A shredder according to claim 44, wherein said sensor is an optical sensor.