Abstract: An epicyclic change speed gear includes a fixed spindle, input and output members, planet pinions disposed in a planet cage, a gear ring which is operatively connected to one of the output member and input member, a clutch operative to connect the input member to one of the planet cage and input member to the gear ring, and axially moveable sun pinions which are resiliently loaded into abutting side-by-side disposition and are rotatable on the spindle. One of the sun pinions is operable to provide a reaction member when locked to the spindle. A gear selector key is disposed radially inwardly of the sun pinions and capable of engaging one of the sun pinions on movement of the selector key in the axial direction of the hub in order to lock the corresponding sun pinion to the spindle to provide the reaction member. The selector key includes a support rod, first and second body parts mounted on the rod for limited relative movement in the axial direction thereof, and a spring.

Abstract: An epicyclic change speed gear comprises a fixed spindle (4) and side-by-side sun pinions (1, 2, 3) rotatable on the spindle. A gear selector key (5) is adapted for selective cooperative engagement with one of the sun pinions to lock that pinion to the spindle. The key (5) is operated by a sleeve (15) disposed for rotational movement relative to the spindle (4). Rotation of the sleeve (15) displaces the key (5) axially to lock the selected sun pinion. One or both axial ends of the sleeve (15) are angled such that different degrees of rotation cause different axial displacements of the key (5) and cause different sun pinions to be locked.