US Patent 7992459 Shifting claw transmission and shifting method therefor

In a shifting claw transmission for a motor vehicle including a main shaft and a countershaft and an electric motor for rotating the countershaft or being rotated thereby with freely rotatable gear wheels supported on the counter shaft and engageable with the countershaft by claw engagement structures, the speed of the countershaft is adjustable by the electric motor to be close to, but somewhat different from, the speed of the freely rotatable gear wheels to be engaged in order to facilitate shifting but avoid a tooth-on-tooth problem which would inhibit shifting.