Single shaft shifting mechanism

A single shaft shifting mechanism (100) for selection and engagement of selectable gear ratios in a change speed transmission (10), said mechanism comprising the housing (H), the shaft (106) mounted for relative axial and rotational movement in said housing, a block member (102) axially and rotationally connected to said shaft, a plurality of shift forks (60A, 62A, 64A) each including a sleevelike hub portion (118, 120 and 122), respectively, each of said hub portions having a through bore (124, 126 and 128, respectively), an outer surface and a pair of axially opposite end surfaces extending generally perpendicular to the axis of said shaft, a set of shift teeth (138, 140, 142, and 144) projecting radially outwardly from said shaft in an axially-spaced relationship such that each of said hub portions is arranged between two adjacent teeth of said set of shift teeth, said shift teeth being axially and circumferentially fixed relative to said shaft, a set of interlocking teeth (150, 152, 154 and 156) projecting radially from said shaft in an axially-spaced relationship such that each of said hub portions is arranged between two adjacent teeth of said set of interlocking teeth, said set of interlocking teeth being axially movable but circumferentially fixed relative to said shaft and axially fixed relative to said housing, each of said hub portions having at least one pair of grooves (184 and 186, 178, 180, and 182, and 174 and 176) extending axially from respective end faces thereof, said grooves being formed to receive a corresponding one of said teeth, said grooves being arranged in predetermined positions along the through bores of said hubs such that when one of said grooves of one of said hubs is aligned with a corresponding one of said interlocking set of teeth and none of the grooves in said hubs is aligned with one of said shifting set of teeth in response to rotation of said shaft, one of said grooves of each hub portion other than said one hub portion is aligned with a corresponding one of said shifting set of teeth and none of the grooves of each of said hub portions other than said one hub portion is aligned with one of said interlocking set of teeth, said shifting mechanism characterized by:

• said grooves extending completely from axial end face to axial end face of each of said hub portions and extending only partially radially outwardly from the inner diameter bores of said hub portions.