Brake mechanisms for a wheel of non-motorized wheeled vehicle such as, e.g., a shopping cart, are described. In various embodiments, the brake mechanism can provide a variable amount of braking force or torque between zero and an amount sufficient to lock the wheel. In some embodiments, the brake mechanism includes a brake plate that is movable toward and away from a surface of the wheel hub along a direction parallel to the rotation axis of the wheel. The brake plate is configured not to rotate when the wheel and hub are rotating. Frictional engagement between the brake plate and the surface of the wheel hub provides the braking force. The brake plate and/or the surface of the wheel hub can include engagement features such as, e.g., protrusions and slots. In some embodiments, the brake mechanism fits entirely within the wheel.

For a caster with a circularly positioning structure, stepping on the pedal can drive the driving rod and the driving piece to rotate, so that the positioning pin of the driving piece cyclically proceeds the first positioning point, the second positioning point and the path point of the positioning member, thereby driving the cam unit to push against the shaft to let the positioning piece and the orienting hole to be engaged or disengaged from each other, and let the locking end of the locking member to be engaged in or disengaged from the locking groove. In this way, the caster can selectively be locked to stop rotation, and be released to freely rotate.

A caster wheel brake system for carts and other wheeled articles is operable to secure caster wheels against rolling rotation along their horizontal rotation axes. The system includes a pivotable parking brake lever, an actuator arm, and a torque shaft extending between the brake lever and actuator arm. The brake lever includes a distal end portion for selectively engaging a caster wheel, a proximal end portion opposite the distal end portion, and a pivot coupling, the latter being pivotably secured to the cart or wheeled article. An actuator arm extends outwardly from a distal end portion of the torque shaft, with the actuator arm slidably engaging the proximal end portion of the brake lever. The torque shaft and the actuator arm are rotatable together to urge the brake lever toward the braking or non-braking position.