Concentric v-groove coupling

A transmission drive-line stage comprising:

• a torque input member;
• a torque reactive member;
• a torque output member;
• and a pair of torque couplings, the torque output member being coupled to the torque input member and the torque reactive member, the torque couplings being configured to transfer torque between the torque input member and the torque output member, each said torque coupling being disposed within a transmission case and being configured to provide a respective gear ratio between the torque input member and the torque output member, each said torque coupling comprising:
• a pair of clutch end members, each said end member including a set of concentric V-grooves disposed on a respective face thereof;
• a clutch centre member disposed between the respective clutch end members, the centre member being axially movable between the respective end members and including a pair of opposing surfaces, one of the opposing surfaces including a plurality of concentric V-grooves configured to mesh with the set of V-grooves of one of the respective end members, another of the opposing surfaces including a plurality of concentric V-grooves configured to mesh with the set of V-grooves of another of the respective end members;
• and
• an actuator coupled to one of the end members and being configured to simultaneously couple the end members to the centre member by urging the V-grooves of both of the respective end members into engagement with the V-grooves of the centre member;
• wherein one of the end members of one of the torque couplings is coupled to the transmission case, the centre member of the one torque coupling is coupled to the torque reactive member, one of the end members of another of the torque couplings is coupled to the torque reactive member, and the centre member of the another torque coupling is coupled to the torque input member.