An exemplary apparatus includes a modular, self-contained spring cage and a spindle. The spring cage includes a housing and a clock spring mounted in the housing, and the clock spring includes a first leg and a second leg. The spindle extends through the spring cage, and is rotatable from a home position about a longitudinal axis in each of a first rotational direction and a second rotational direction. Rotation of the spindle from the home position in the first rotational direction causes pivoting of the first leg while the second leg remains stationary, thereby causing the clock spring to urge the spindle to return to the home position. Rotation of the spindle from the home position in the second rotational direction causes pivoting of the second leg while the first leg remains stationary, thereby causing the clock spring to urge the spindle to return to the home position.