A shaft shielding assembly (26) comprising first and second telescopic sleeve members (31, 32) is provided. The sleeve members are each disposed around, and shield a portion of a rotatable shaft (22). Mutually cooperating guide means, such as an array of grooves and ridges (33, 34), are provided on the sleeve members and which forcibly reduce longitudinal overlap therebetween when rotated with respect to one another so as to extend the shielded region of the shaft.
