Forage harvester adjustment apparatus

An adjustment apparatus for use with a chopper drum, in which the chopper drum is supported from a housing and mounted for rotation about a rotational axis and comprises a plurality of circumferentially spaced knife supports to which at least one chopper knife is adjustably secured, the adjustment apparatus comprising:

• a lateral element;
• at least one location element for location of the adjustment apparatus with respect to the chopper drum;
• and
• at least one radially inwardly directed guide surface, describing an outer path of a unworn chopper knife, wherein the at least one guide surface is adjustably located with respect to the lateral element;
• wherein the at least one guide surface is on an individual spacer element, and the spacer element is adjustably located with respect to the lateral element, and wherein the spacer element comprises:
• first and second portions, wherein the first portion comprises:
• the guide surface;
• and
• the lateral element comprising first and second limbs.