Speed change hub and braking construction

A braking construction used in a speed-change hub, said construction comprising:

• a fixed shaft;
• a hub body and a drive member rotatably supported by the fixed shaft, respectively;
• a power transmission for transmitting a drive force from the drive member to the hub body, when the drive member is rotated in a driving direction;
• a braking mechanism having a braking member for braking rotation of the hub body when the drive member is rotated in a reverse direction relative to said driving direction;
• a brake control claw supported by a member cooperating with the drive member for engaging with a first member associated with the braking member when the drive member is rotated in the reverse direction to thereby rotate the first member in the reverse direction with the drive member;
• a second member rotated in the reverse direction at higher angular speed than the first member when the first member is rotated in the reverse direction;
• and
• a transmission claw supported by a member cooperating with the drive member for engaging with the second member when the drive member is rotated in the driving direction to rotate the second member in the driving direction with the drive member;
• disengaging means for disengaging the transmission claw from the second member when the drive member is rotated in the reverse direction, said disengaging means including a claw cage relatively rotatable in the driving direction with respect to the member cooperating with the drive member to forcibly disengage the transmission claw from the second member and to cause the brake control claw to engage with the second member, said claw cage being restricted in rotation with respect to at least one of the first and the second member.

A speed-change hub comprising:

• a fixed shaft;
• a hub body and a drive member rotatably supported by said fixed shaft, respectively;
• a power transmission for transmitting a drive force from said drive member to the hub body, said power transmission mechanism comprising:
• a plurality of rotatable planetary gears,
• a plurality of sun gears meshing with said plurality of planetary gears, respectively, and having diameters differing from each other, said sun gears being rotatable independently from said fixed shaft and being substantially limited in axial movement;
• a lock control mechanism for locking and unlocking said plurality of sun gears with respect to said fixed shaft, and
• a control member for externally controlling said lock control mechanism to provide a plurality of speeds by selecting among said sun gears to be locked,
• said lock mechanism including engaging portions disposed between said fixed shaft and the respective sun gears, and lock claws engageable with said engaging portions,
• said control member being relatively rotatable with respect to the fixed shaft at least in the vicinity of said sun gears, said control member including a plurality of control portions for contacting said lock claws corresponding to a position of relative rotation between the control member and the fixed shaft to select engagement or disengagement between the lock claws and the engaging portions.

A speed-change hub comprising:

• a fixed shaft;
• a hub body and a drive member rotatably supported by said fixed shaft, respectively;
• a power transmission for transmitting a drive force from said drive member to said hub body;
• a support member disposed between the fixed shaft and the drive member for supporting the drive member to the fixed shaft;
• and
• a control member rotatably operable relative to the fixed shaft for externally effecting a speed change operation through said power transmission,
• said support member and said fixed shaft having a guide groove defined therebetween,
• said control member being provided with a fork portion extending through said guide groove and being relatively rotatable with respect to said support member.