# US 8,783,592 B2 · Shredder with thickness detector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,592 B2 - Document ID: US8783592B2 - Status: Granted - Kind: B2 - Application number: 12/732,899 - Filed: 2010-03-26 - Published: 2010-08-26 - Granted: 2014-07-22 - Earliest claimed: 2005-07-11 - Assignees: Fellowes, Inc. - Applicants: Tai Hoon K. Matlin; Eric Gach - Inventors: Tai Hoon K. Matlin; Eric Gach - Web page: https://patentgrep.com/patent/US8783592B2 ## CPC - B02C 23/06: Selection or use of additives to aid disintegrating - B02C 18/0007: {specially adapted for disintegrating documents} - B02C 18/16: Details - B02C 23/04: Safety devices (in general F16P {; for rotary mills B02C13/31}) - B02C 23/18: Adding fluid, other than for crushing or disintegrating by fluid energy ({for tumbling mills B02C17/186;} feeding devices B02C23/02) - B26D 7/088: {by cleaning or lubricating (sterilizing B26D1/00)} - B02C 2018/0015: {for disintegrating CDs, DVDs and/or credit cards} - B02C 2018/0023: {Switching devices} - B02C 2018/164: {Prevention of jamming and/or overload} - B02C 2018/166: {Lubricating the knives of the cutting mechanisms} - B02C 2018/168: {User safety devices or measures in shredders} - 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}) - B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04) ## Abstract A shredder is disclosed. The shredder includes a housing having a throat for receiving at least one article to be shredded, and a shredder mechanism received in the housing and including an electrically powered motor and cutter elements. The shredder mechanism enables the at least one article to be shredded to be fed into the cutter elements. The motor is operable to drive the cutter elements so that the cutter elements shred the articles fed therein. 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 operable to perform a predetermined operation responsive to the detector detecting that the thickness of the at least one article is at least equal to a predetermined maximum thickness. ## Claims ### Claim 1 A shredding machine for shredding sheet material, the machine comprising a feed aperture and a cutting mechanism powered by an electric motor, the feed aperture being arranged to receive sheet material for shredding and to direct such sheet material to the cutting mechanism for shredding, the machine having means for measuring the thickness of sheet material passed into said feed aperture for shredding which sheet material may comprise a plurality of superimposed sheets which together provide such thickness, said measuring means controlling said cutting mechanism so as to permit energisation of the cutting mechanism where the thickness of sheet material measured thereby is below a controlling threshold and to prevent such energisation where the thickness of sheet material measured is above said controlling threshold, characterised in that the machine includes at least one input for inputting a variable parameter relevant to such shredding and control means operable to adjust said controlling threshold in dependence upon the value of the parameter input. ### Claim 2 (depends on 1) A machine according to claim 1 wherein said measuring means includes an actuating element which is movable from a first limiting position engaging or relatively close to one major wall of said aperture, away from said major wall, against a biasing force acting on said element, and means for measuring displacement of said actuating element from said limiting position. ### Claim 3 (depends on 2) A machine according to claim 2 wherein said means for measuring displacement of said actuating element comprises a marker member provided with a series of markers and optical sensing means sensitive to the passage of said markers past said sensors, said member being part of, or mechanically coupled with, said actuating element so that the displacement of said actuating element will cause said marker member to move so as to cause said markers to traverse past said sensors. ### Claim 4 (depends on 3) A machine according to claim 3 wherein said optical sensing means comprises two optical sensors disposed at different positions along said series of markers to allow said control means to determine the direction of displacement of the marker member as well as the extent of such movement. ### Claim 5 (depends on 4) A machine according to claim 4 wherein said actuating element engages said one major wall of said passage when no such sheet material is present therein, the control means being arranged, at times during operation of the machine when said actuating element is in engagement with said major wall of the apparatus, to adopt the corresponding position of said actuating element as corresponding to zero material thickness. ### Claim 6 A shredding machine for shredding sheet material, the machine comprising a feed aperture and a cutting mechanism powered by an electric motor, the feed aperture being arranged to receive sheet material for shredding and to direct such sheet material to the cutting mechanism for shredding, the machine having a detector for detecting the thickness of sheet material passed into said feed aperture for shredding which sheet material may comprise a plurality of superimposed sheets which together provide such thickness, said detector controlling said cutting mechanism so as to permit energisation of the cutting mechanism where the thickness of sheet material measured thereby is below a controlling threshold and to prevent such energisation where the thickness of sheet material measured is above said controlling threshold, characterised in that the machine includes at least one input for inputting a variable parameter relevant to such shredding and a controller operable to adjust said controlling threshold automatically in dependence upon the parameter input. ### Claim 7 (depends on 6) A machine according to claim 6 wherein said detector includes an actuating element which is movable from a first limiting position engaging or relatively close to one major wall of said aperture, away from said major wall, against a biasing force acting on said element, and a sensor for measuring displacement of said actuating element from said limiting position. ### Claim 8 (depends on 7) A machine according to claim 7 wherein said sensor for measuring displacement of said actuating element comprises a marker member provided with a series of markers and an optical sensor sensitive to the passage of said markers past said sensors, said member being part of, or mechanically coupled with, said actuating element so that the displacement of said actuating element will cause said marker member to move so as to cause said markers to traverse past said sensors. ### Claim 9 (depends on 8) A machine according to claim 8 wherein said optical sensor comprises two optical sensors disposed at different positions along said series of markers to allow said controller to determine the direction of displacement of the marker member as well as the extent of such movement. ### Claim 10 (depends on 9) A machine according to claim 9 wherein said actuating element engages said one major wall of said passage when no such sheet material is present therein, the controller being arranged, at times during operation of the machine when said actuating element is in engagement with said major wall of the apparatus, to adopt the corresponding position of said actuating element as corresponding to zero material thickness. ### Claim 11 A shredding machine for shredding sheet material, the machine comprising a feed aperture and a cutting mechanism powered by an electric motor, the feed aperture being arranged to receive sheet material for shredding and to direct such sheet material to the cutting mechanism for shredding, the machine having a thickness measuring device for measuring the thickness of sheet material passed into said feed aperture for shredding which sheet material may comprise a plurality of superimposed sheets which together provide such thickness, said thickness measuring device controlling said cutting mechanism so as to permit energisation of the cutting mechanism when the thickness of sheet material measured thereby is below a controlling threshold and to prevent such energisation when the thickness of sheet material measured is above said controlling threshold, characterised in that the machine includes at least one input for inputting a variable parameter relevant to such shredding, and a controller operable to adjust said controlling threshold in dependence upon the value of the parameter input.