Patent attributes
An electro-pneumatic switching unit for a vehicle transmission (6) comprising one splitter group transmission (12) pneumatically switched via valves (36, 38) and one range-change group transmission (14) pneumatically switched via valves (44, 46), the switchings of which are manually preselected by the vehicle driver on a gear lever (16), has one locking device (54, 56) for mechanically preventing the manual switching of inadmissible reduction ratios of the vehicle transmission (6), one device (30, 42, 64) for preventing the pneumatic switching of inadmissible reduction ratios and one electronic control device (20). The locking device (54, 56) for mechanically preventing the manual switching of inadmissible reduction ratios is pneumatically connected with one valve (44) for switching the range-change group transmission (14).
