An adjustment assembly or mechanism that permits adjustment of the height and angle of tilt of a vehicle seat includes front and rear latch gears with multiple cogs corresponding to discrete angular positions of the latch gears and consequently discrete heights of the front and rear of the adjustment assembly. The front latch gears pivot about a fixed pivot axis while the rear latch gears pivot about a sliding pivot axis to accommodate tilt angles for the seat. Torsion springs bias the four latch gears to a maximum rotation or pivot position in which the respective ends of the seat are at their highest vertical position. A spindle engages the cogs of the latch gears to hold the latch gears in a particular discrete angular position. Separate front and rear manual actuation levers at the front of the seat can be lifted to release a respective front and rear spindle from a particular cog and allow the driver to adjust the seat position. The independent front and rear adjustment mechanisms allow the driver to place the seat in a wide range of heights and tilt angles, including forward and rearward tilt angles.

An adjustment assembly or mechanism that permits adjustment of the height and angle of tilt of a vehicle seat includes front and rear latch gears with multiple cogs corresponding to discrete angular positions of the latch gears and consequently discrete heights of the front and rear of the adjustment assembly. The front latch gears pivot about a fixed pivot axis while the rear latch gears pivot about a sliding pivot axis to accommodate tilt angles for the seat. Torsion springs bias the four latch gears to a maximum rotation or pivot position in which the respective ends of the seat are at their highest vertical position. A spindle engages the cogs of the latch gears to hold the latch gears in a particular discrete angular position. Separate front and rear manual actuation levers at the front of the seat can be lifted to release a respective front and rear spindle from a particular cog and allow the driver to adjust the seat position. The independent front and rear adjustment mechanisms allow the driver to place the seat in a wide range of heights and tilt angles, including forward and rearward tilt angles.

A clutch unit includes a lever-side clutch section provided on an input side, for controlling rotational torque to be input through lever operation, and a brake-side clutch section provided on an output side, for transmitting the rotational torque from the lever-side clutch section to the output side, and interrupting rotational torque to be reversely input from the output side. The brake-side clutch section has a two-layer structure, in which two one-way clutches are arranged side by side in an axial direction. The first one-way clutch interrupts rotational torque in a forward direction, which is reversely input from the output side, through meshing of serrated projection and depression portions, whereas the second one-way clutch interrupts rotational torque in a backward direction, which is reversely input from the output side, through meshing of serrated projection and depression portions arranged in an opposite direction.