Multiple speed hub with coaster brake

In a multiple-speed hub for a bicycle and like vehicle including a shaft defining an axis of rotation;

• a tubular driver mounted on said shaft for rotation about said axis;
• a hub shell having two axially terminal portions mounted on said shaft and on said driver respectively for rotation about said axis;
• a multiple-shaped planetary transmission drivingly interposed in said hub shell between said driver and said hub shell, said transmission including a sun gear fixed on said shaft, a planet carrier member and an internally toothed ring gear member rotatable about said axis, a planet gear rotatably mounted on said planet carrier member in simultaneous meshing engagement with said sun gear and with said ring gear member, a coupling element secured to said driver for joint rotation, shifting means for shifting said coupling element between positions of driving engagement with said members respectively, and two clutches drivingly interposed between said hub shell and said members respectively, one of said clutches including:
• a driven portion and a driving portion respectively secured to a first one of said members and to said hub shell for simultaneous rotation about said axis, said portions being radially offset, one of said portions being formed with a recess radially open toward the other portion, a pawl having a pivot part and an engagement part, said pivot part being received in said recess for pivoting movement of said pawl toward and away from a position of engagement of said engagement part with said other portion;
• a brake actuating element supported on one of said members for threaded movement about said axis toward and away from an axial position of braking action on said hub shell;
• and yieldable means impeding rotation of said brake actuating element relative to said shaft, whereby axial movement of said brake actuating element relative to said supporting member is caused when said supporting member rotates about said axis;
• the improvement in said one clutch which comprises:
• a. two circumferentially spaced end faces of said one portion bounding said recess in two opposite circumferential directions,
• 1. said end faces being cylindrically arcuate about respective axes of curvature,
• 2. a cylindrically convex face of said pivot part being shaped for conforming, movable engagement with each of said end faces;
• b. a convexly arcuate bottom face of said one portion bounding said recess in a radially inward direction,
• 1. one of said axes of curvature being nearer said axis of rotation than the other axis of curvature, whereby said bottom face slopes from one of said end faces toward the other end face in a radially inward direction,
• 2. the length of said bottom face being sufficient for permitting circumferential movement of said pawl in said recess between respective positions of engagement of said pivot part with said end faces.