SHREDDING MACHINE

• US 20170232443A1
• Filed: 05/04/2017
• Published: 08/17/2017
• Est. Priority Date: 08/02/2007
• Status: Active Grant

• Current Assignee: ACCO Brands Incorporated
• Original Assignee: ACCO UK Ltd. (ACCO Brands Incorporated)
• Inventors: Aries, Paul A., Sawford, Michael D.
• Granted Patent: US 10,576,476 B2
• Time in Patent Office: Days
• CPC Class Codes: B02C 18/0007 specially adapted for disintegrating documents
• CPC Class Codes: B02C 2018/0023 Switching devices
• CPC Class Codes: B02C 2018/164 Prevention of jamming and/or overload
• CPC Class Codes: G01B 21/08 for measuring thickness

Abstract

A shredding machine for domestic or office use having a feed passage 3 leading to a cutting mechanism 10, 11 powered by an electric motor, has a thickness measuring device 15 for measuring the thickness of bundles of paper fed through the feed passage and the machine is controlled by a microprocessor which receives signals from the thickness measuring device and prevents the cutting mechanism from being energised if the thickness measured is above a threshold determined by the microprocessor. The thickness gauging device is deactivated during shredding until the material is shredded so that rippling or flapping of the material within the feed passage will not cause false readings as to the amount of material inserted into the feed passage.

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;

a 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 thickness detector, the controller being configured to determine, prior to operation of the motor, whether the thickness detector detects that the thickness of the at least one article to be shredded being received by the throat is below or at or above a predetermined maximum thickness threshold, and in response;

(a) prevent operation of the motor if the thickness detector detects that the at least one article to be shredded being received by the throat is at or above predetermined maximum thickness threshold, and

(b) operate 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 thickness detector detects that the at least one article is below the predetermined maximum thickness threshold, without preventing the operation of the motor in the shredding direction in response to the thickness detector detecting during the operation of the motor that the thickness of the at least one article is at or above the predetermined maximum thickness threshold to thereby prevent unnecessary motor shut-off due to fluttering of the at least one article being shredded.

2. A shredder according to claim 1, wherein the thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thicknesses.

3. A shredder according to claim 2, wherein said 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.

4. A shredder according to claim 3, wherein said sensor is an optical sensor.

5. A shredder according to claim 4, wherein said thickness detector comprises a marker member provided with a series of markers movable with the contact member, said optical sensor detecting the markers moving past the optical sensor to measure the amount of displacement of the contact member.

6. A shredder according to claim 5 wherein said optical sensor comprises two optical sensors disposed at different positions to allow said controller to determine the direction of displacement of the marker member as well as the extent of such movement.

7. A shredder according to claim 2, further comprising a presence sensor, separate from the thickness detector, in the throat for determining whether the at least one article has been inserted into the throat.

8. A shredder according to claim 1, wherein the controller comprises a microcontroller.

9. A shredder according to claim 1, wherein the controller is 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.

10. A shredder according to claim 1, wherein said thickness detector includes a contact member in the throat movable by engagement of the at least one article being received in the throat, and a sensor for detecting movement of the contact member.

11. A shredder according 10, wherein said sensor is an optical sensor.

12-28. -28. (canceled)

29. A method for operating a shredder comprising a housing having a feed passage for receiving material to be shredded, a thickness gauging device for detecting a thickness of the material to be shredded inserted in the feed passage, and a shredding machine received in the housing and including an electrically powered motor and cutters, the shredding machine enabling the material to be shredded to be fed into the cutters and the motor being operable in a shredding direction to drive the cutters to shred the material fed therein;

the method comprising;

prior to operation of the motor, determining whether the thickness gauging device detects that the thickness of the material to be shredded received by the feed passage is less than or greater than a capacity threshold thickness;

operating the motor in the shredding direction to drive the cutters to shred the material received by the feed passage if the thickness gauging device detects that the material is less than the capacity threshold thickness; and

deactivating the thickness gauging device during shredding until the material is shredded so that rippling or flapping of the material within the feed passage will not cause false readings as to the amount of material inserted into the feed passage.

30. The method of claim 29, wherein the thickness gauging device remains deactivated until the inserted paper clears a paper detection sensor.

31. The method of claim 30, wherein the thickness gauging device is reactivated after the inserted paper clears the paper detection sensor.

32. 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;

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

a sensor for monitoring a motor operating condition during the operation of the motor in the shredding direction; and

a controller that determines, prior to operation of the motor, whether the thickness detector detects that the thickness of the at least one article to be shredded being received by the throat violates a predetermined maximum thickness threshold, and in response;

(a) prevents operation of the motor if the thickness detector detects a violation of the predetermined maximum threshold thickness, and (b) 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 thickness detector does not detect a violation of the predetermined maximum thickness threshold,

wherein the controller thereafter continues the operation of the motor in the shredding direction without using the thickness detector for determining whether to stop the operation, and wherein the controller stops the operation of the motor in the shredding direction if the motor operating condition monitored by the sensor indicates the motor is overloaded by the at least one article.

33. A shredder according to claim 32, wherein the thickness detector is a variable thickness detector for detecting and outputting varying amounts of detected thicknesses.

34. A shredder according to claim 33, wherein said 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.

35. A shredder according to claim 34, wherein said sensor of the thickness detector is an optical sensor.

36. A shredder according to claim 35, wherein said thickness detector comprises a marker member provided with a series of markers movable with the contact member, said optical sensor detecting the markers moving past the optical sensor to measure the amount of displacement of the contact member.

37. A shredder according to claim 36, wherein said optical sensor comprises two optical sensors disposed at different positions to allow said controller to determine the direction of displacement of the marker member as well as the extent of such movement.

38-59. -59. (canceled)