Reverse brake for manual transmissions

摘要

A synchronizer unit eliminates the chattering noise generated when shifting a manual transmission into reverse from a forward gear while the drive shaft continues to rotate in the direction corresponding with the forward gear by providing a reverse brake arrangement for arresting rotation of the input shaft. The reverse brake arrangement includes a shaft rotatably supported by the transmission housing and a clutch hub mounted on the shaft which is adapted to rotate with the shaft. The clutch hub has a splined outer circumference. A shift sleeve is provided for engagement with the splined outer circumference of the clutch hub and is movable in the axial direction of the shaft. The reverse brake mechanism further includes a frustoconical cone in coaxial relation to the shaft and disposed on a first side of the clutch hub. The frustoconical cone includes a frustoconical surface on its outer periphery. A first blocker ring is coaxially aligned with the shaft. The first blocker ring including a conical surface adapted to be fitted on the frustoconical surface of the frustoconical cone, such that axial translation of the shift sleeve in a direction toward the frustoconical cone urges the first blocker ring against the frustoconical cone. The frustoconical cone is mounted in the housing for limited rotation and includes at least one tang extending therefrom.