the following description is merely exemplary in nature and is not intended to limit the present disclosure , application , or uses . it should be understood that throughout the drawings , corresponding reference numerals indicate like or corresponding parts and features . referring to fig1 , an illustrated hydraulic circuit receives fluid from a hydraulic pressure source 2 , by passing through an inlet filter 4 . the pressurized fluid is transmitted to the circuit by a safety solenoid valve 6 , which is open in an activated position in order to feed the hydraulic control circuit , and which is closed in the absence of signal in order to improve safety , by putting this circuit in communication with a reservoir 10 at atmospheric pressure . afterwards , the arriving pressurized fluid passes via a sequence valve 12 , which , in a first controlled position , provides the feeding of an upper pressure line 16 by the pressure source 2 so as to deliver energy to the hydraulic machine 30 operating as a motor , the return of the fluid to the reservoir 10 being done via a lower pressure line 18 . in a second controlled position , the sequence valve 12 reverses these two connections , by feeding of the lower pressure line 18 by the pressure source 2 so as to make the hydraulic machine 30 operate as a motor in the other direction , the return to the reservoir 10 being done via the upper pressure line 16 . the sequence valve 12 includes a central rest position which connects the two pressure lines 16 , 18 to the reservoir 10 with significant flow rate restrictions so as to allow for a progressive drop of pressure in the control circuit . the return to the reservoir 10 is done by a pressure - limiting valve 8 , maintaining a pressure of 10 bars in the return line , which may be the upper 16 or lower 18 line , depending on the position of the sequence valve 12 . the hydraulic machine 30 includes a control of its variable displacement , which is not represented in this diagram . a leakage return 20 recovers the leakages of the hydraulic machine 30 and its variable displacement control to convey them toward the reservoir 10 . two check valves 22 , 24 comprising a calibration spring calibrated to 0 . 5 bars , are disposed between the leakage return 20 and the upper pressure line 16 as well as the lower pressure line 18 , in order to avoid overpressure in this leakage return when discharging the fluid in one of these two pressure lines . the hydraulic machine 30 directly drives , via a speed reduction gear 32 , a first screw - ball nut type mechanical cylinder 36 and , via flexible shafts 34 which allow turning around the nacelle of the turbojet engine , other similar mechanical cylinders 36 which then have a synchronized movement . thus , a linear displacement of the thrust reverser is achieved , this remaining parallel to the axis of the nacelle . a manual control device 46 allows directly driving the flexible shafts 34 by a control handle , in order to maneuver the mechanical cylinders 36 in the event of a stoppage or breakdown of the motorization . thus , possibilities of intervention or maintenance are provided . a mechanical brake 38 comprising stacked brake discs , disposed at the end of the line of the flexible shafts 34 , is controlled by a hydraulic cylinder 40 comprising a load spring which constantly maintains the brake closed in the case of absence of hydraulic pressure . a hydraulic valve 42 , comprising a closed position when at rest and an open position when active , controls this brake . in this manner , improved safety is provided by stopping the movement of the actuators 36 and by maintaining their positions , in the case of a failure of the control of the solenoid valve 42 or of the hydraulic pressure . a bypass hydraulic valve 50 disposed parallel to the hydraulic machine 30 , includes , at rest , an open position which frees a fluid passage between the upper pressure line 16 and the lower pressure line 18 , and when in the closed position , interrupts this passage thereby allowing this machine to operate . an equalizer valve 52 disposed between the lower connection of the hydraulic machine 30 and the lower pressure line 18 , is controlled by the pressure of the upper line 16 in order to automatically adapt a fluid passage restriction at the outlet of this machine when it operates as a generator , based on its output pressure as well as on the pressure of the upper line feeding it . thus , braking of the hydraulic machine 30 operating as a generator is automatically achieved , in order to dissipate a braking power in the pressure return toward the reservoir 10 . as a complement , another equalizer valve , which is not represented , may be disposed in the same manner on the upper pressure line 16 at the inlet of the hydraulic machine 30 so as to retain the load on this machine if stopped , without urging the mechanical brake 38 . the operation of this control circuit includes at the beginning of the movement of the thrust reverser being deployed , positioning of the hydraulic machine 30 in a large displacement in order to obtain a high starting torque with the supply via the upper pressure line 16 , then switching into a reduced displacement in order to obtain a high speed of displacement with a low fluid consumption . during this displacement , a closure of the flaps of the thrust reverser disposed in the cold air annular flow path is achieved , which flaps return the flow through the diverting means forwardly of the aircraft . the thrust of the cold air flow on the flaps generates a large load on these flaps which tends to close them , their strokes then drive the hydraulic machine 30 which switches into the generator operation mode , with a braking of this machine by the equalizer valve 52 disposed at the outlet . as we approach the end - of - stroke , a large displacement of the hydraulic machine 30 is then progressively reestablished , in order to obtain a more and more significant braking torque depending on the decrease of its speed of rotation . in order to close the thrust reverser , a similar cycle is performed with a reverse movement of the hydraulic machine 30 , this machine operating first as a motor with a supply by the lower pressure line 18 , connected to the pressure source 2 by positioning the sequence valve 12 in the corresponding position . in most cases , stresses are considerably reduced at the end of the stroke of the thrust reverser , in particular after high translational speeds in the middle of the stroke , by the large - displacement position of the hydraulic machine 30 delivering a high braking torque . moreover , the regulating distributor of the displacement of the hydraulic machine 30 is advantageously adjusted based on the level of the load pressure of this machine , thereby allowing for a flexible adaptation allowing to simplify the initially - provided speed ramp tracking control . it is then possible in this case to choose a regulating distributor of the displacement which is less accurate than a servo valve , including proportional control solenoids which may be controlled in a closed loop based on the thrust reverser stroke measured by a sensor which measures a rotation or a displacement of a mechanical element related to the displacement of this thrust reverser . in particular , it is possible to pilot this regulating distributor of the displacement in a simple manner by pulse width modulation , of the “ pwm ” ( pulse width modulation ) type . it will be noted that proportional control distributors are generally less accurate than servo valves , which is compensated by the higher flexibility of piloting given by the variation of the displacement of the hydraulic machine 30 . as a variant , a more complex servo - control includes measuring the control pressure of the variable displacement of the hydraulic machine 30 in order to servo - control this adjustment of displacement more accurately . one or several variable displacement motor ( s ) may be used in the context of the present disclosure . the use of several motors includes many advantages , in particular a redundancy for enhancing the operational availability of the function . the description of the disclosure is merely exemplary in nature and , thus , variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure . such variations are not to be regarded as a departure from the spirit and scope of the disclosure .