Patent ID: 7428854

Claim:
A mainshaft assembly for a gearbox, the mainshaft assembly comprising: a mainshaft; a first and a second drive gear, each carried for rotation about the mainshaft, each drive gear having a different number of teeth; a first and a second hub, each hub being associated with a respective drive gear, each hub having engagement means operable to selectively couple with the drive gear causing it to rotate with the hub or uncouple from the drive gear to allow the drive gear to rotate with respect to the hub; respective drive connection means associated with each hub being operative to connect or disconnect the hub to the mainshaft for rotation with it or to allow rotation with respect to it; wherein, upon connection of both first and second hub by their respective engagement means to each corresponding drive gear, the drive connection means operates to connect one of the hubs to the mainshaft when torque is applied to the mainshaft through the hub and to connect the other one of the hubs to the mainshaft when torque is applied to the hub through the mainshaft.