Mechanism for preventing misoperation in a manual transmission

Claim 1

In combination with a manual transmission for an automotive vehicle having a transmission casing, a shift-and-select lever shaft mounted on said transmission casing and effective to rotate about and slide along its axis, said shift-and-select lever shaft being adapted to coact with a speed change lever, shift heads of fork shafts for a low speed gear, first-second speed gears, third-fourth speed gears and fifth-reverse speed gears, a shift-and-select lever fixed to and projecting laterally from said shift-and-select lever shaft, said shift-and-select lever being selectively engagable with any one of said shift heads by rotation of said shift-and-select lever shaft and a drive changing shaft arranged in parallel relation with said shift-and-select lever shaft and adapted to move along its axis in said transmission casing, said drive changing shaft effecting change from a two-wheel drive operation to a four-wheel drive operation and vice versa by its axial movement; a mechanism for preventing misoperation in a manual transmission comprising a stopper arm projecting laterally from said shift-and-select lever shaft and a stopper surface formed on one end of said drive changing shaft, said stopper surface being in abutment against said stopper arm under the condition that said shift-and-select lever is engaged with said shift head for the first-second speed gears to prevent said shift-and-select lever from rotating toward said shift head for the low speed gear in the two-wheel drive operation.