Travel end expansion valve for piston type pressure converter

Travel end expansion valve (1) which is provided for a piston type pressure converter (2) which comprises at least one master cylinder (3) in which a main master piston (7) can move so as to define a master chamber (9) which has a variable volume and which can be placed in a relationship with a master intake conduit (22) by a master intake valve (18) or with a master discharge conduit (23) by a master discharge valve (19), the pressure converter (2) also comprising at least one slave cylinder (4), in which a slave pump piston (8) can move so as to define a slave chamber (10) which also has a variable volume, the chamber (10) being able to admit a hydraulic fluid from a slave intake conduit (24) via a slave intake valve member (20) or to discharge the fluid into a slave discharge conduit (25) via a slave discharge valve member (21), the master chamber (9) and the slave chamber (10) each being filled with a hydraulic fluid, characterized in that it comprises:

• at least one expansion master cylinder (12) which is filled with a hydraulic fluid and in which an expansion main master piston (14) can move so as to define an expansion master chamber (16) which has a variable volume and which communicates with the master chamber (9) and/or at least one expansion master cylinder (12) which is filled with a hydraulic fluid and in which an expansion main master piston (14) can move so as to define an expansion master chamber (16) which has a variable volume and which communicates with the slave chamber (10);
• at least one expansion slave cylinder (13) which cooperates with the expansion master cylinder (12) and in which an expansion slave pump piston (15) can move so as to define with the slave cylinder (13) an expansion slave chamber (17) which has a variable volume and which is filled with a hydraulic fluid, the slave pump piston (15) being mechanically connected to the expansion main master piston (14) by a lever type transmission (11) which has a progressive effect and which is arranged in such a manner that, when the expansion main master piston (14) is at the top dead center, the expansion slave pump piston (15) is at the bottom dead center, and vice versa;
• at least one expansion slave intake valve member (26) which opens in the expansion slave chamber (17) and which allows a hydraulic fluid which is contained in an expansion slave intake conduit (28) to be introduced into the slave chamber (17) but not to be discharged therefrom;
• at least one expansion slave discharge valve member (27) which opens in the expansion slave chamber (17) and which allows a hydraulic fluid which is contained in an expansion slave discharge conduit (29) to be discharged from the slave chamber (17) but not to be introduced therein;
• at least one expansion release actuator (30) which can, by means of contact or mechanical connection, cause to move or release the lever type transmission (11) with progressive effect.