| 摘要 |
<p>A hydraulic device for activating a brake, comprising: a hollow body (2) affording a first opening (21) for connection to a pressurised fluid source (60), also affording a second opening (22) for connection to an actuator (50) for activating a brake, also affording a third opening (23); an obturator (3), mobile internally of the hollow body (2) between at least a first position, in which the first opening (21) and the second opening (22) are not connected to one another, and at least a second position, in which the obturator (3) connects the first opening (21) and the second opening (22) to one another, means for pushing (70) being provided for pushing the obturator (3) from the at least a second position towards the at least a first position; a pilot element (4) predisposed to push the obturator (3) from the at least a first position into the at least a second position, which pilot element (4) is mobile between at least a first position, in which it is not in contact with the obturator (3) and the obturator (3) is free to assume the at least a first position thereof, and at least a second position, in which the pilot element (4) is in contact with the obturator (3) and can push the obturator (3) into the at least a second position thereof; the pilot element (4) being conformed in such a way as to place the second opening (22) in communication with the third opening (23) if it is not in contact with the obturator (3).</p> |
