Countershaft gear transmission

Claim 1

A countershaft gear transmission comprising: an input shaft; a countershaft drivingly connected to said input shaft; a main shaft; a one way clutch including an inner first race surrounded by an outer second race, said second race being formed with a first main gear, said first race being rotatably mounted on said main shaft and having an extension protruding axially away from said first main gear through and beyond a bearing rotatably supporting said extension; a second main gear rotatably mounted on said main shaft; a first counter gear in constant meshing engagement with said first main gear and integral with said countershaft; a second counter gear in constant meshing engagement with said second main gear; means coupled with said main shaft for rotation therewith, for coupling the end of the extension on said first race of said one-way clutch with said main shaft in all forward gear ratios including a predetermined gear ratio and the next higher gear ratio; clutch means, coupled with said main shaft for rotation therewith, for coupling said second main gear with said main shaft in said higher gear ratio; the speed reduction between said first main gear and said first counter gear being smaller than that between said second main gear and said second counter gear, said one-way clutch being constructed such that it allows rotation of said first race to overrun said second race, thus absorbing a difference in rotational speed between said first race and said second race formed with said first main gear when said higher gear ratio is established, and such that when said predetermined gear ratio is established it allows unitary rotation of said first race and said second race formed with said first main gear, whereby shifting between said predetermined gear ratio and said higher gear ratio can be effected with said input shaft being subjected to torque stress.