Elevator which counterweight is also the plunger of the propelling fluid dynamic device which produces and controls the movements thereof

ELEVATOR which counterweight is also a plunger of a propelling fluid dynamic device which produces and controls the movements thereof of the type comprising a car for conveying either people or things that moves between vertical guides disposed inside a vertical conduit having walls, said car being supported on a cable extending to an upper pulley, and, changing direction, it projects to a counterweight balanced with said car, characterized in that said pulley is supported from the vertical conduit walls and is kept in a freely-rotating condition, while the balanced counterweight is a hollow piston-counterweight, accommodated in a cylinder vertically disposed in the vertical conduit itself, adjacent to the car, both forming part of the propelling fluid dynamic device which produces upward and downward movements of the car, which is completed with a fluid circulation circuit, which comprises at least a driving pump coupled to valve means,

• wherein the vertically disposed cylinder has upper and lower bases thereof closed, and which inner part defines two variable volume chambers, the chambers being spaced apart by the piston-counterweight, both chambers are individually connected to a respective conduit for the fluid flow, extending to the driving pump of the propelling device.