Gear wheel support

A gear support supporting a gear wheel having a plurality of internal teeth and a plurality of external teeth;

• wherein said internal teeth (8) of said gear wheel (4) has at least one discontinuity provided therein;
• said gear support comprises a first disc having a plurality of external teeth which correspond to said internal teeth (8) of said gear wheel (4), said first disc has at least one mating discontinuity formed in said plurality of external teeth which is located to coincide with said discontinuity of said internal teeth (8) of said gear wheel (4), said external teeth of said first disc are insertable through said internal teeth (8) of said gear wheel (4) into a groove (30) provided in said gear wheel (4), and said first disc is at least partially rotatable within said groove (30) whereby coincidence of said internal teeth (8) of said gear wheel (4) and said external teeth of said first disc and coincidence of said at least one discontinuity of said internal teeth (8) and said at least one mating discontinuity of said plurality of external teeth is obtainable;
• and
• a locking mechanism of said gear support cooperates with said discontinuities, once said discontinuities coincide with one another, to lock the coincident position of said gear wheel (4) relative to said first disc.