# US 8,464,767 B2 · Shredder thickness with anti-jitter feature > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,767 B2 - Document ID: US8464767B2 - Status: Granted - Kind: B2 - Application number: 13/360,198 - Filed: 2012-01-27 - Published: 2012-05-17 - Granted: 2013-06-18 - Earliest claimed: 2007-10-04 - Assignees: Fellowes, Inc. - Applicants: Tai Hoon K. Matlin; Michael Dale Jensen - Inventors: Tai Hoon K. Matlin; Michael Dale Jensen - Web page: https://patentgrep.com/patent/US8464767B2 ## CPC - B02C 25/00: Control arrangements specially adapted for crushing or disintegrating - B02C 18/0007: {specially adapted for disintegrating documents} - B02C 18/16: Details - B02C 2018/0038: {Motor drives} - B02C 2018/164: {Prevention of jamming and/or overload} - B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02}) ## 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 ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 1) A shredder according to claim 1, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 6 (depends on 2) A shredder according to claim 2, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 7 (depends on 4) A shredder according to claim 4, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 2) 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. ### Claim 10 (depends on 3) 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. ### Claim 11 (depends on 8) 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. ### Claim 12 (depends on 11) A shredder according to claim 11, wherein said sensor is an optical sensor. ### Claim 13 (depends on 1) 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. ### Claim 14 (depends on 1) A shredder according to claim 1, wherein the at least one thickness detector comprises a binary thickness detector. ### Claim 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. ### Claim 16 (depends on 15) A shredder according to claim 15, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 17 (depends on 16) A shredder according to claim 16, wherein the predetermined operation further comprises actuating an indicator to alert a user. ### Claim 18 (depends on 15) 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. ### Claim 19 (depends on 18) 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. ### Claim 20 (depends on 19) A shredder according to claim 19, wherein said sensor is an optical sensor. ### Claim 21 (depends on 15) 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. ### Claim 22 (depends on 16) A shredder according to claim 16, wherein the at least one thickness detector comprises a binary thickness detector. ### Claim 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. ### Claim 24 (depends on 23) 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. ### Claim 25 (depends on 24) 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. ### Claim 26 (depends on 23) 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. ### Claim 27 (depends on 23) A shredder according to claim 23, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 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. ### Claim 29 (depends on 28) A shredder according to claim 28, wherein the predetermined operation comprises preventing operation of the motor in the shredding direction. ### Claim 30 (depends on 1) A shredder according to claim 1, wherein the at least one thickness detector is a single thickness detector. ### Claim 31 (depends on 30) 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. ### Claim 32 (depends on 31) 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. ### Claim 33 (depends on 32) A shredder according to claim 32, wherein said sensor is an optical sensor. ### Claim 34 (depends on 15) A shredder according to claim 15, wherein the at least one thickness detector is a single thickness detector. ### Claim 35 (depends on 34) 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. ### Claim 36 (depends on 35) 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. ### Claim 37 (depends on 36) A shredder according to claim 36, wherein said sensor is an optical sensor. ### Claim 38 (depends on 23) A shredder according to claim 23, wherein the at least one thickness detector is a single thickness detector. ### Claim 39 (depends on 38) 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. ### Claim 40 (depends on 39) 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. ### Claim 41 (depends on 40) A shredder according to claim 40, wherein said sensor is an optical sensor. ### Claim 42 (depends on 28) A shredder according to claim 28, wherein the at least one thickness detector is a single thickness detector. ### Claim 43 (depends on 42) 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. ### Claim 44 (depends on 43) 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. ### Claim 45 (depends on 44) A shredder according to claim 44, wherein said sensor is an optical sensor.