Abstract: A coupling for engaging and disengaging a drive means (12) from a driven member (10), the coupling comprising a stress absorbent coupling member (20), a shaft (22), operably connected to a drive (12), and an actuating member (28), the coupling member being slidably mounted on the shaft (22) such that on operation of the actuating member (28), the coupling member is caused to slide along the shaft (22) between a first position at which the drive is disengaged from the driven member and a second position at which the drive engages the drive member.