| 摘要 |
<p>Theft of a bicycle is discouraged by a locking mechanism in the front headstem that controllably engages the handlebar-attached headstem with the front fork or disengages the headstem and fork for free relative rotation. A shaft attached to the fork and a sleeve attached to the handlebar clamp are connected at a locking junction which is rotatable as a whole in the front journal of the frame. A key operated cam moves a locking roller radially outwardly of the shaft to engage a receptacle in the sleeve for engagement or allows the roller to retract into an aperture for disengagement. The shaft and sleeve have complementary conical tapers axially positioned by a split conical bushing. A cylinder lock operates the cam via a key having a substantially tubular configuration with a uniquely configured axial end for positioning lock pins against axial spring pressure. The key has a radially protruding guide tab, and fits into an annular key receptacle with two longitudinal slots, one for the guide tab upon insertion of the key, and the other capturing the key via the guide tab in the locking position of the lock. The key has a rounded end cap configured to cover a top of the frame headstock.</p> |
