Device for controlling the sharpening state of a blade (2) having a cutting edge (20) delimited by two sides (21, 22) converging towards a plane (X) that contains the cutting edge itself. The device comprises two control surfaces each of which is in contact with a corresponding side (21, 22) of the cutting edge (20) and is connected with a transducer (R4), which produces an electrical displacement signal (S4) proportional to a displacement of the control surface with respect to said plane (X). Furthermore, the device comprises a processing unit (E) that receives said displacement signals (S4) and compares them, emitting an error signal if the comparison produces a value that exceeds a predetermined limit. The control surfaces are the surfaces that delimit an external groove (40) of a roller (4) that is free to translate along an axis (A4) perpendicular to said plane (X) and spaced from the blade (2) by an amount such that said cutting edge (20) passes in said groove (40).

Device for controlling the sharpening state of a blade (2) having a cutting edge (20) delimited by two sides (21, 22) converging towards a plane (X) that contains the cutting edge itself. The device comprises two control surfaces each of which is in contact with a corresponding side (21, 22) of said cutting edge (20) and is connected with at least one transducer (R1, R2, R4), which produces an electrical displacement signal (S1, S2; S4) proportional to a displacement of the control surface with respect to said plane (X). Furthermore, the device comprises a processing unit (E) that receives said displacement signals (S1, S2, S4) and compares them, emitting an error signal if the comparison produces a value that exceeds a predetermined limit. The processing unit is connected to means (101, 102) for supporting and moving sharpening means (100).

A knife sharpening device has a holder that has a slot for receiving a blade of a circular knife. At least one sharpening rod is pivotally mounted on the holder against the force of a spring. At least one first sharpening insert is arranged on the sharpening rod. The slot extends eccentrically into the holder transversely to a longitudinal axis of the holder. At least one additional sharpening insert is positioned on an outer side of the holder.

A cutting machine includes a circular knife and a grinding unit for grinding the circular knife, wherein the grinding unit can be adjusted to grind the circular knife at different angles.

Device for controlling the sharpening state of a blade (2) having a cutting edge (20) delimited by two sides (21, 22) converging towards a plane (X) that contains the cutting edge itself. The device comprises two control surfaces each of which is in contact with a corresponding side (21, 22) of the cutting edge (20) and is connected with a transducer (R4), which produces an electrical displacement signal (S4) proportional to a displacement of the control surface with respect to said plane (X). Furthermore, the device comprises a processing unit (E) that receives said displacement signals (S4) and compares them, emitting an error signal if the comparison produces a value that exceeds a predetermined limit. The control surfaces are the surfaces that delimit an external groove (40) of a roller (4) that is free to translate along an axis (A4) perpendicular to said plane (X) and spaced from the blade (2) by an amount such that said cutting edge (20) passes in said groove (40).

Device for controlling the sharpening state of a blade (2) having a cutting edge (20) delimited by two sides (21, 22) converging towards a plane (X) that contains the cutting edge itself. The device comprises two control surfaces each of which is in contact with a corresponding side (21, 22) of said cutting edge (20) and is connected with at least one transducer (R1, R2, R4), which produces an electrical displacement signal (S1, S2; S4) proportional to a displacement of the control surface with respect to said plane (X). Furthermore, the device comprises a processing unit (E) that receives said displacement signals (S1, S2, S4) and compares them, emitting an error signal if the comparison produces a value that exceeds a predetermined limit. The processing unit is connected to means (101, 102) for supporting and moving sharpening means (100).