Interlock mechanism in vehicle transmission

An interlock mechanism associated with a shift mechanism for a change-speed gearing in a power transmission, said shift mechanism including three parallel fork shafts axially slidably supported from a casing of said power transmission to be selectively shiftable toward forward speed-ratio and reverse-ratio positions, said casing being formed with an end wall placed in a plane perpendicular to each axis of said fork shafts and to slidably support said fork shafts extending therethrough,

• wherein said interlock mechanism comprises a single interlock plate assembled with said end wall of said casing to be movable only in one direction, said interlock plate having a body portion slidably guided at a proximal side thereof in said one direction and a pair of spaced parallel projections integrally formed with a distal side of said body portion to be selectively engaged with respective recesses formed on each of said three parallel fork shafts for permitting axial movement of one of said fork shafts and restricting axial movement of the remaining two of said fork shafts.