The present invention is related to a wheelchair provided with a steering mechanism that can be progressively blocked or released. The wheelchair is equipped with a powered device, for example a variable length actuator, configured to actuate the movement of a protruding movable member able to engage with a receptacle attached to the steering mechanism. The steering angle is diminished progressively as the moveable member is further introduced into the receptacle, and when the member is retracted, the steering angle is again progressively increased. The shape of the moveable member and the inner surface of the receptacle is such that when the member is introduced into the receptacle, the steering action causes the member and said inner surface to come into contact, thereby limiting the steering angle. The degree to which the steering angle is limited is higher as the member enters further into the receptacle. According to a preferred embodiment, full blockage of the steering mechanism is reached when the member is fully extended.
