Swivel caster

A mobile cart comprising

• a caster-support hub,
• a swivel caster mounted on the caster-support hub for swiveling movement relative to the caster-support hub about a vertical rotation axis from a centered position in a counterclockwise direction to a left-swivel position or from the centered position in a clockwise direction to a right-swivel position,
• a caster-controller coupled to the caster-support hub for applying a yieldable clockwise torque to the swivel caster to urge the swivel caster to rotate about the vertical rotation axis in a clockwise direction to the centered position from the left-swivel position, and, alternatively, a yieldable counterclockwise torque to the swivel caster to urge the swivel caster to rotate in a counterclockwise direction to the centered position from the right-swivel position during movement of the mobile cart so that the swivel caster is maintained generally in the centered position while the mobile cart is in motion, and
• wherein the caster-controller includes a right-side centering spring, a left-side centering spring, and a swivel-rotation limiter including a first spring seat coupled to the swivel caster to rotate therewith about the vertical rotation axis and associated with the right-side centering spring, a second spring seat coupled to the swivel caster to rotate therewith about the vertical rotation axis and associated with the left-side centering spring, a lockout plate mounted on the swivel caster for rotation about the vertical rotation axis relative to the spring seats, a first spring post coupled to the lockout plate to rotate therewith, and a second spring post coupled to the lockout plate to rotate therewith, and wherein the right-side centering spring is arranged to lie in a first spring-receiver space to act against the first spring post and the first spring seat to store potential energy in response to rotation of the swivel caster about the vertical rotation axis in the counterclockwise direction from the centered position to the right-swivel position, and wherein the left-side centering spring is arranged to lie in a second spring-receiver space to act against the second spring post and the second spring seat to store potential energy in response to rotation of the swivel caster about the vertical rotation axis in the clockwise direction from the centered position to the left-swivel position,
• wherein the caster is adjustable between a self-centering configuration in which the lockout plate is fixed to the caster-support hub and a free-swiveling mode in which the lockout plate is free to swivel with respect to the caster-support hub.