Speed change device for gearbox

摘要

A shifting arrangement for a manual transmission having several forward gears and at least one reverse gear has a shift rotor that is rotated to shift the transmission gears. For this purpose, the shift rotor is connected by way of a cable pull with a shift lever. By moving the shift lever forward or backward from a neutral position, the shift rotor is rotated by way of a step-by-step system. In order to ensure a secure shifting of the reverse gear with a clear assignment for the driver and a protection against an unintended shifting, the reverse gear is operated by moving the shift lever in a second channel which is separate from the forward-gear shifting channel. For this purpose, the shift lever is connected by way of a second cable pull with a preselection shaft. By rotating the preselection shaft, coupling elements can be adjusted between the shift forks and the shift rotor irrespective of their shifting position. By means of the locking elements between the shifting shaft and the preselection shaft, a shifting of individual transmission gears is allowed only if a previously defined shifting position existed.