A milling system to comminute a material may generally include a hopper feeder system, a cutting mill, a collection system, each in fluid communication to provide a flow path, and a control system. The control system may include a controller operatively connected to at least one sensor to sense the amount of material, if any, along the flow path, and the speed, if any, of the material along the flow path. The control system, in response to signals received from the at least one sensor, may cause at least one of the hopper feeder, cutting mill, and collection system to increase the speed, decrease the speed, or stop the flow of material along at least a portion of the flow path. Methods of making and using the same are also described.

An under-sink disposal unit includes a motor, a disposal chamber, and a disposal throat. The disposal throat extends from the disposal chamber to an opening in a top of the disposal unit and defines a passageway through which objects pass into the disposal chamber for grinding. The disposal unit further includes a coil assembly including an arrangement of coils. The arrangement of coils is used to detect the passing of a metallic object in the passageway through the disposal throat. Furthermore, the arrangement of coils includes at least one coil having a loop that is oriented with respect to an axis of the passageway through the disposal throat such that objects passing through the disposal throat into the disposal chamber pass by and proximate to, but do not pass through, such loop. Preferably DC injection braking is used to stop the motor upon detection of a metallic object.

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.

A screen for a shredder machine has a shape that avoids clogging of the materials being processed through the shredder. The screen has a pair of mounting plates that are connected to the shredder with one mounting plate attached toward the top of the rotor and the other mounting plate attached toward the bottom of the rotor and extending the entire length of the rotor. Arcuate ribs are attached to and extend between the mounting plates, and a grid is attached to the ribs.

An under-sink disposal unit includes a motor, a disposal chamber, and a disposal throat. The disposal throat extends from the disposal chamber to an opening in a top of the disposal unit and defines a passageway through which objects pass into the disposal chamber for grinding. The disposal unit further includes a coil assembly including an arrangement of coils. The arrangement of coils is used to detect the passing of a metallic object in the passageway through the disposal throat. Furthermore, the arrangement of coils includes at least one coil having a loop that is oriented with respect to an axis of the passageway through the disposal throat such that objects passing through the disposal throat into the disposal chamber pass by and proximate to, but do not pass through, such loop. Preferably DC injection braking is used to stop the motor upon detection of a metallic object.

A paper shredder having shredder cover and a motor coupled to shredder blades includes a shredder throat coupled to an inlet in the shredder cover and in proximity to shredder blades. The shredder throat has a moveable throat blade, which widens the shredder throat. An anti-jam switch, which when activated causes the motor to advance the shredder blades to clear a jam in the widened shredder throat. The jam clearing mechanism can be automatic or manual, as by push-button or turn-knob linkages. A method for recovering from a shredder jam in a paper shredder is provided, including providing a moveable throat blade; sensing a shredder throat jammed condition; releasing the moveable throat blade; moving the moveable throat blade to a wide gap position; sensing the moveable throat blade in the wide gap position; advancing shredder blades in response to the sensing, by which the jammed condition is cleared.

A document shredder is disclosed including a paper receptacle for receiving a load of paper and a shredding assembly. A metering assembly is interposed between the paper receptacle and the shredding assembly and is configured to separate a portion of the load of paper from the load of paper and permit the portion of the load of paper to move into the shredding assembly. The metering assembly may include a stop plate secured thereto and defining a lifting portion on a perimeter portion thereof. The lifting portion is configured to engage a lower edge of the portion of the load of paper upon rotation of the stop plate and lift the paper over the stop plate. The lifting portion may include a flange, which may be a portion of a cone, formed on a perimeter portion of the wheel and occupying a sector of the perimeter of less than 60 degrees.

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 energized if the thickness measured is above a threshold determined by the microprocessor. The microprocessor varies the threshold in accordance with electrical supply voltage, the electric motor temperature and the electric current drawn by the motor during a previous shredding operation, so that the maximum thickness the shredder will accept can be reduced automatically when motor temperature increases or as the effectiveness of the machine deteriorates throughout its working life.

A shredder includes a strip-cut shredding portion including paired disc-shaped, multi-plate rotary cutters meshing with each other to shred paper in a strip-cut direction, and a cross-cut shredding portion including a fixed cutter and a spiral rotary cutter for further shredding strip-cut waste pieces discharged from the strip-cut shredding portion in a cross-cut direction, the shredder including a unit for detecting that the spiral rotary cutter of the cross-cut shredding portion is not rotating. Shredding by the strip-cut shredding portion is stopped when the sensor unit detects that the spiral rotary cutter is not rotating.

A novel safe paper feed opening structure of a paper shredder, having a shredder upper cover and a paper shredder plate. The shredder upper cover has an opening, and the paper shredder plate is at the opening. The opening communicates with a moveable feed throat. The paper shredder plate can be configured in one of four positions. The moveable feed throat has a normal opening and a wide opening. The feed throat can be moved to the wide opening when the shredder plate is in a JAM CLEAR/OFF position. The CLOSED/OFF, NORMAL/ON, and SHRED-SAFE/OFF positions use a normal feed throat. A method for operating a paper shredder includes providing a shredder upper cover; providing the shredder upper cover with an opening; disposing a paper shredder plate at the opening; disposing the opening in communication with a moveable feed throat; and moving the feed throat responsive to a paper shredder condition.