Dual clutch type power transmission with alternative torque transmission path providing alternative ratios

A method for configuring a transmission to provide an alternative gear ratio wherein the transmission comprises:

• an input;
• an output;
• a first transmission section providing one or more stages of gearing and configurable to provide one of a first plurality of gear ratios between the input and the output;
• a second transmission section providing one or more stages of gearing configurable to provide one of a second plurality of gear ratios between the input and the output;
• a first clutch operable to selectively couple the input to the first transmission section;
• a second clutch operable to selectively couple the input to the second transmission section;
• wherein:
• the first transmission section comprises a first shaft and a first torque coupling connecting the first shaft to drive the output, the first torque coupling comprising one or more gears carried by the first shaft in constant mesh with the one or more gears of the output wherein the transmission comprises a mechanism for selectively engaging or disengaging the first torque coupling;
• the second transmission section comprises a second shaft and a second torque coupling connecting the second shaft to drive the output, the second torque coupling comprising one or more gears carried by the second shaft in constant mesh with the one or more gears of the output;
• the method comprising disengaging the first torque coupling and configuring a torque transfer mechanism to transfer torque from the first shaft to the second shaft to provide an alternative torque transmission path from the input to the output that includes at least one of the one or more stages of gearing of the first transmission section and at least one of the one or more stages of gearing of the second transmission section and provides one or more gear ratios between the input and the output that is different from the gear ratios of the first and second pluralities of gear ratios.

A transmission comprising:

• an input;
• an output;
• a first transmission section providing one or more stages of gearing and configurable to provide one of a first plurality of gear ratios between the input and the output;
• a second transmission section providing one or more stages of gearing configurable to provide one or more second gear ratios between the input and the output;
• a first clutch operable to selectively couple the input to the first transmission section;
• a second clutch operable to selectively couple the input to the second transmission section;
• and,
• a torque transfer mechanism selectively operable to transfer torque from the first transmission section to the second transmission section to provide an alternative torque transmission path from the input to the output that includes at least one of the one or more stages of gearing of the first transmission section and at least one of the one or more stages of gearing of the second transmission section and provides one or more gear ratios between the input and the output that is different from the first plurality of gear ratios and the one or more second gear ratios
• wherein:
• the first transmission section comprises a first shaft carrying one or more gears arranged to be driven by the first clutch and one or more gears arranged to drive the output;
• the second transmission section comprises a second shaft carrying one or more gears arranged to be driven by the second clutch and arranged to drive the output;
• and,
• the torque transfer mechanism comprises a torque transfer component separate from any components providing the first plurality of gear ratios and the second plurality of gear ratios.