Internally accommodated speed change mechanism applicable to a bicycle
AssigneeXenoah Co.
InventorKazuo Nakajima
Life of this patent
Estimating the term…
Abstract
A bicycle speed change mechanism in which five speeds are obtained with mechanism contained internally within the hub of a bicycle wheel. A pair of planetary gear mechanisms are mounted on a hub axle within a hub body, and two separate speed change rods are provided to selectively and separately control operation of the planetary gear mechanisms to obtain five numerically-different drive ratios. The separate speed change rods are manipulated at the control of the bicycle rider to select gear ratios ranging from the lowest to the highest available gear.
Claims9
An internally accommodated speed change mechanism applicable to a bicycle, comprising in combination:
- a hub axle;
- a hub body mounted for free rotation on said hub axle;
- a first planetary gear mechanism mounted on said hub axle within said hub body;
- a second planetary gear mechanism mounted on said hub axle within said hub body;
- said first planetary gear mechanism having a first sun gear freely rotatable on said hub axle, a first planetary gear in engagement with said first sun gear, and a first ring gear in engagement with said first planetary gear;
- said second planetary gear mechanism having a second sun gear freely rotatable on said hub axle, a second planetary gear in engagement with said second sun gear, and a second ring gear in engagement with said second planetary gear;
- a first carrier connected to said second ring gear and retaining said first planetary gear for rotation about said first sun gear;
- ratchet means associated with said second ring gear and meshing with said hub body;
- a sleeve operatively associated with a drive sprocket and freely rotatable on said hub axle, said sleeve being axially slidable on said hub axle;
- first means on said sleeve to selectably engage said first carrier when said sleeve is at a certain axial position on said hub axle, so that said first carrier and said first planetary gear are rotated by rotation of said drive sprocket;
- a first speed change rod disposed in said hub axle for selective axial movement and operatively associated with said sleeve to axially move said sleeve to place said first means in said selectable engagement;
- a second speed change rod disposed in said hub axle for selective axial movement independently of said first speed change rod;
- and
- means associated with said second speed change rod to selectably connect either said first sun gear or said second sun gear to said hub axle in response to a certain axial position of said second speed change rod.
Dependencies are inferred from the claim text.