control valve is not open application_number US 53771295 A description the similarity in presentation of fig1 and 2 has been chosen to allow an appreciation to be gained of the characteristics common to the invention fig2 and to the prior art fig1 as well as their differences as these figures show the invention relates in a known fashion to a proportional solenoid valve for regulating the pressure of a hydraulic fluid this valve being provided overall with a high pressure inlet 1 with a low pressure inlet 2 and with an outlet 3 on which it can deliver the fluid under a controlled pressure a body 4 pierced with a bore 5 connecting first and second end chambers 6 and 7 together these further being connected to one another permanently by a longitudinal duct 8 a regulating slide valve 9 sliding within the bore 5 and having a cross section s for differential pressure capable of constituting the seat of application of a first force due to the pressure and capable of urging this slide valve towards the first end chamber 6 a spring 10 or any other elastic means exerting a second force of elastic nature pointing in the opposite direction from the first force on the slide valve first and second.