Cutting and grinding apparatus, method of manufacture of cut lengths of tobacco, and method for controlling the operation of a cutting apparatus

A grinder assembly for removing material from the cutting edge of at least one knife of a cutting apparatus, said cutting apparatus comprising

• a mouth defined by a jaw assembly for delivering material to be cut to a cutting position at the said mouth;
• a cutting drum having;
• at least one knife, said knife having a cutting edge,
• the said cutting drum having a driver therefor and being rotatable about an axis arranged substantially parallel to the mouth such that the cutting edge of said at least one knife is arranged substantially perpendicular to the material to be cut;
• the grinder assembly comprising a grinder unit having a grinder and the driver and a controller therefor, the grinder comprising a cylinder having a cylindrical surface comprising a substantially constant radius, the grinder being configured to be rotated about an axis arranged substantially parallel to the axis of rotation of the cutting drum, first wherein
• the grinder is configured to be brought into contact with the cutting edge with a first movement in a first direction substantially parallel to the axis of rotation of the said cutting drum and with a second movement in a second direction substantially opposite to the first direction and substantially parallel to the axis of rotation of the cutting drum, wherein the grinder is configured to execute the first movement in the first direction at a substantially uniform first speed and the second movement in the second direction at a substantially uniform second speed, wherein the first speed is different to the second speed.

A method of manufacture or cut lengths of tobacco, comprising the steps of:

• delivering the tobacco material to be cut to a cutting position at a mouth defined by a jaw assembly;
• rotating a cutting drum having a cutting edge about an axis arranged substantially parallel to the mouth such that the cutting edge is arranged substantially perpendicular to the material to be cut;
• and
• bringing a grinder into contact with the cutting edge with a first movement in a first direction substantially parallel to the axis of rotation of the cutting drum and with a second movement in a second direction substantially opposite to the first direction and substantially parallel to the axis of rotation of the cutting drum, wherein the grinder is configured to execute the first movement in the first direction at a substantially uniform first speed and the second movement in the second direction at a substantially uniform second speed, wherein the first speed is different to the second speed, and
• thereby grinding the cutting edge.