HUB RATCHET DRIVING DEVICE FOR BICYCLES
A hub ratchet driving assembly includes a hub and a driving member is connected to an end of the hub. The driving member includes a driving portion which has first and second recesses defined in an outer surface thereof so as to receive a pawl and a spring member therein. A teeth ring is connected to the hub and includes multiple teeth in an inner periphery thereof. The spring member biases the pawl so as to provide a return force to the pawl. The pawl includes two ratchet teeth which are engaged with the teeth of the teeth ring. A positioning unit has a first positioning slot defined in the driving portion and a second positioning slot is defined in the pawl. A positioning ring is mounted to the first and second slots so as to prevent the pawl from disengaging from the driving portion in axial direction.
1 . A hub ratchet driving assembly comprising:
a hub;
a driving member being a hollow tube and a driving portion formed on one end of the driving member, the driving portion having first and second recesses defined in an outer surface thereof;
a ratchet unit having a teeth ring connected to an inside of the hub and the teeth ring including multiple teeth defined in an inner periphery thereof, a pawl and a spring member respectively received in the first and second recesses, the spring member biasing the pawl so as to provide a return force to the pawl, a portion of the pawl protruding from the first recess and including two ratchet teeth which are engaged with the teeth of the teeth ring, and
a positioning unit having a first positioning slot defined in the driving portion and an end surface located beside the pawl, the end surface and the pawl define a second positioning slot, a positioning ring mounted to the first and second slots, one side of the positioning ring contacting the pawl so as to prevent the pawl from disengaging from the driving portion in axial direction.
2 . The assembly as claimed in claim 1 , wherein the first and second positioning slots share a common axis.
3 . The assembly as claimed in claim 1 , wherein the driving portion extends through the teeth ring and the teeth are engaged with both of the two ratchet teeth.
4 . The assembly as claimed in claim 1 , wherein the hub includes a connection end and the teeth ring is threadedly connected to the connection end, the driving portion, the first recess and the second recess are integrally formed as one piece.
5 . The assembly as claimed in claim 1 , wherein the positioning ring is a closed ring.
6 . The assembly as claimed in claim 1 , wherein the positioning ring C-shaped ring.
7 . The assembly as claimed in claim 1 , wherein the positioning ring is made of resilient material.
8 . The assembly as claimed in claim 1 , wherein the first positioning slot is located close to a distal end of the driving portion and extends radially relative to the driving portion, the second positioning slot is defined in the pawl and located corresponding to the first positioning slot.