Abstract:
A starter for an internal combustion engine, comprising: an electric motor; a drive assembly including a pinion movable between a free position and a meshed position, wherein the pinion is rotatably linked to the electric motor and the internal combustion engine; an electric switching device including a main actuator capable, when engaged, of moving and holding a plunger, in position, the plunger being linked with the movement of the pinion between the free position and the meshed position, by means of a lever; a means connected to the plunger, which is capable of establishing electrical power contact between the electric motor and a power source when the pinion is in the meshed position; and including an auxiliary actuator capable, when engaged, of opening the power contact and a means for separately controlling the main actuator and the auxiliary actuator.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY 
     This application is a national stage application of International Application No. PCT/FR2012/053036 filed Dec. 21, 2012, which claims priority to French Patent Application No. 1162255 filed Dec. 22, 2011, of which the disclosures are incorporated herein by reference and to which priority is claimed. 
     FIELD OF THE INVENTION 
     The invention relates to a multi-contactor device, in particular for controlling an electric starter. More particularly but not exclusively, the invention is designed for controlling the electric starter of an internal combustion engine for a vehicle comprising a restarting device, commonly known as a restarter, which makes it possible to stop the functioning of the thermal engine by cutting off its fuel supply when the said engine is no longer participating in the propulsion of the vehicle, and to restart the said engine rapidly. 
     BACKGROUND OF THE INVENTION 
     According to an embodiment in the prior art, a starter comprises a launcher, which is mobile in translation and rotated by an electric motor. At its end, the launcher comprises a pinion which can engage with a toothed crown which is integral in rotation with (i.e., non-rotatably connected to) the crankshaft of the internal combustion engine. In order to start an internal combustion engine, it is necessary to increase its speed of rotation to approximately 200 rpm. According to the mode of use known in the prior art, the starter is used when the engine is at a standstill. 
       FIG. 1 , which relates to the prior art, illustrates schematically an electric starter of this type, in its position of rest with the engine at a standstill. When a contact  110  is closed, power is supplied to a solenoid  120 . This solenoid comprises a coil  121  known as a pull-in coil, and a coil  122  known as a hold-in coil. The power supplied to the solenoid  120  gives rise to the translation of a plunger  130 . During this translation, the plunger  130  drives a pinion  160  of a launcher in translation by means of a fork, which is also known as a lever  161 , which pinion  160  then engages with a crown  190  which is connected in rotation (i.e., non-rotatably) to the crankshaft of the engine. Thus, the plunger  130  and the pinion  160  are integral in translation according to this embodiment in the prior art. At the end of the course of the plunger  130 , by means of a contact plate  131 , the plunger establishes electrical contact between an armature  151  of an electric motor  150 , and a positive terminal  101  of the vehicle battery. The electric motor  150  then rotates the pinion  160  of the launcher (as the electric motor  150  is non-rotatably connected to the pinion  160 ), which drives the crown  190  and launches the rotation of the internal combustion engine. In this position, with the contact plate  131  establishing the power circuit between a vehicle battery  100  and the armature of  151  the electric motor  150 , the pull-in coil  121  is short-circuited, and the plunger is retained in position by the effect of the hold-in coil  122 . When the contact  110  is open, the magnetic forces generated by the effect of the hold-in coil  122  and the pull-in coil  121 . This is due to the fact that the direction of the current in the pull-in coil is inverted. In addition, when the contact  110  is open, a compression spring  132  thrusts the plunger  130  back, thus opening the contact previously established by the contact plate  131 , and separating the pinion  160  from the crown  190 . The connection in rotation (i.e., non-rotatable connection) of the pinion  160  to the electric motor  150  is provided by means of a free wheel mechanism  165 , such that the pinion  160  is separated from the motor  150  when it is driven by the crown  190 . This device according to the prior art gives satisfaction for the initial starting of the engine, when the engine is started by actuating the contact key, or by pressing a starter button. 
     The lever which is supported against a housing of the starter comprises play, known as the cut-off play  161 , in order to allow the plate  131  to move away from the terminals in the case of an abnormality of the pinion blocked in the crown. The lever against the housing provides a pivot connection and translation perpendicular to the pivot. 
     Many vehicles are equipped with an automatic stop-restarting device known as “stop and go”. According to this device, the internal combustion engine is cut-off automatically as soon as the vehicle is at a standstill, i.e. the running of the engine at idling speed is not maintained when the vehicle is at a standstill. When the driver is preparing to set off once more, for example when he presses the clutch, the engine is automatically restarted. This functioning mode makes it possible to save fuel in the phases where it is not necessary to have the engine running. Although this restarting is rapid, it is not instantaneous. In addition, according to the prior art, the fuel supply to the engine is also cut-off when the vehicle is in the engine brake situation, i.e. when the driver is not pressing the vehicle accelerator. According to the prior art, the cut-off of the supply to the thermal engine is continued until the engine reaches a predetermined speed corresponding for example to 1500 rpm, thus making it possible to maintain the supply to the engine in order to keep it running at least at idling speed, even if the said engine is not participating in the propulsion of the vehicle. In fact, it is considered that the internal combustion engine can no longer start autonomously in all situations, when its speed drops below a certain threshold of approximately 300 rpm. However, the starter according to the prior art, the functioning of which has previously been described, needs the engine to be at a standstill in order to begin to function, as a result of the balancing phase during which the starter cannot put its pinion into the crown. Thus, when a vehicle is equipped with a restarter device, it is necessary to detect that the thermal engine has actually stopped. The solutions according to the prior art thus lead to complex control of the system for stopping and restarting of the engine. 
     For example, the engine is not stopped, but is kept idling, for as long as the driver is exerting pressure on the clutch, even if the gearbox is in neutral and the vehicle is stopped. Since the restarting is not instantaneous, the driver tends to maintain pressure on the clutch when he anticipates a short-term stoppage, thus depriving himself of fuel savings. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to resolve the disadvantages of the prior art, and for this purpose it relates to a starter for an internal combustion engine, which starter comprises: 
     an electric motor; 
     a launcher comprising a pinion which is mobile between a position, known as the free position, in which this pinion is connected in rotation to the said electric motor alone, and a position, known as the meshed position, in which the said pinion is connected in rotation to the electric motor and the internal combustion engine; 
     an electric switch comprising a main actuator which, when it is engaged, can displace and maintain in position a means, known as the plunger, the said plunger being connected with the displacement of the pinion, between the free position and the meshed position, by a connection means, known as a lever; 
     means connected to the plunger, known as the contact plate, which can establish electrical power contact between the electric motor and a power source, when the pinion is in the meshed position; 
     an auxiliary actuator, which, when it is engaged, can open the power contact or prevent the closure of the power contact, and means for controlling the main actuator and the auxiliary actuator separately. 
     Thus, the starter which is the subject of the invention can be used according to a functioning mode corresponding to that of a starter according to the prior art when the auxiliary actuator is not actuated, and in addition it provides a specific functioning mode in which the pinion of the launcher is meshed, for example with a crown which is connected to the crankshaft of the internal combustion engine, without being driven by the electric motor, and without the said electric motor subjecting the said pinion to resistant torque. 
     Thus, the pinion can be meshed with the said crown when the internal combustion engine is rotating at reduced speed, in particular in the phase of deceleration of the thermal engine. 
     Thus, the time for restarting the internal combustion engine is reduced, with the pinion already being engaged, and connected in rotation with the crown. 
     In addition, in the case of starting of the thermal engine required when the engine is in the balancing phase, since the pinion is already in the crown, it is no longer necessary to wait for the end of stoppage of the thermal engine in order to start the thermal engine, since the pinion is already inserted in the crown. 
     The invention can be implemented according to the advantageous embodiments described hereinafter, which can be considered individually, or according to any technically operative combination. 
     Advantageously, the main actuator and the auxiliary actuator are solenoids. 
     Advantageously, the switch comprises an input terminal which is connected to the power source, and an output terminal which is connected to the electric motor, in particular to the armature, with the contact plate establishing an electrical connection between the input terminal and the output terminal and comprises: 
     a disconnecting switch, which is actuated by the auxiliary actuator, and establishes additional electrical contact between the plate and the positive terminal of the electric motor. 
     This embodiment requires little modification of the device according to the prior art, which shares numerous parts with the starter which is the subject of the invention, and thus this embodiment is more particularly advantageous in terms of production cost. 
     According to a variant of these embodiments, the output terminal is connected electrically to the brushes of the electric motor, and not to the armature. 
     According to a second variant embodiment of the starter which is the subject of the invention, the switch comprises an input terminal which is connected to the power source, and an output terminal which is connected to the electric motor, the said starter comprising: 
     a contact plate which is mobile relative to the plunger, according to a degree of freedom which is stopped in contact with the said terminals; 
     means which are actuated by the auxiliary actuator, and can retain the said plate in contact with one of the terminals by means of a movement according to the said degree of freedom. 
     According to this embodiment, the auxiliary device, which acts essentially mechanically, is less subject to the phenomena of arcing or adhesion of the contacts. Thus, this embodiment is more advantageous in terms of reliability. 
     According to an embodiment of this second variant of the starter which is the subject of the invention, the plunger is displaced by the main actuator according to a course in axial translation, and the degree of freedom of the contact plate is a translation parallel to the said course. This embodiment to be produced requires little modification in comparison with a device according to the prior art. 
     According to another embodiment of the second variant of the starter which is the subject of the invention, the plunger is displaced by the main actuator according to a course in axial translation, and the degree of freedom of the contact plate is a rotation of the axis perpendicular to the axis of the course. This embodiment improves the reliability, since the opening and closure of the contact take place on only one terminal, and it also permits production of a more compact device. 
     Advantageously, the lever comprises means which allow the pinion to remain in the crown when the latter is at a standstill whilst there is no longer any power supply to the pull-in coil and the hold-in coil. Thus, the pinion of the launcher is retained in the crown of the internal combustion engine when the said engine is stopped, in order to reduce the restarting time. 
     Advantageously, resilient means act on the means actuated by the auxiliary actuator, thus adding their action to that of the said actuator, in the same sense as that of this actuator when it is engaged. Thus, when the device which is the subject of the invention is at rest, according to this embodiment the auxiliary actuator is in a configuration corresponding to that of the first steps of starting of the internal combustion engine, such that the starting time is reduced. 
     The invention also relates to a method for functioning of a starter according to one of the embodiments of the invention, the said method comprising the steps consisting of: 
     obtaining a threshold of speed of rotation of the internal combustion engine, known as the engagement threshold; 
     obtaining the speed of rotation of the said engine; 
     if the speed of rotation descends below the engagement threshold, actuating the main actuator and the auxiliary actuator, such as to connect the pinion of the launcher in rotation with the crankshaft of the internal combustion engine; 
     disengaging the auxiliary actuator and the main actuator; 
     receiving a request for starting of the thermal engine; 
     disengaging the main actuator, such as to supply power to the electric motor  150  and rotate the pinion  160  of the launcher; then 
     engaging the main actuator when the internal combustion engine reaches a defined speed of rotation. 
     Thus, a few milliseconds is gained in the case of conventional starting, since the pinion is already in the crown, and in addition it is possible to reduce the time by one second when the request for starting the thermal engine is implemented whilst the thermal engine is in the balancing phase. 
     Thus, the pinion of the launcher is pre-engaged integrally in rotation with the internal combustion engine whilst the latter is rotating, and the electric motor does not exert any resistant torque on the said pinion, such that the restarting time of the engine is reduced. 
     According to an embodiment of the method which is the subject of the invention, a stop command is issued to the thermal engine before step iii., and the engagement threshold is set to 50 rpm. Thus, in the situation of stoppage of an engine, the pinion is engaged at a reduced speed of rotation, such as to limit its wear. 
     Advantageously, according to this embodiment of the method which is the subject of the invention, when a request for starting is issued before step iv., the said method replaces steps iv, v and vi by a step consisting of: 
     disengaging the auxiliary actuator such as to supply power to the electric motor  150  and rotate the pinion  160  of the launcher after stoppage of the internal combustion engine, and disengaging the auxiliary actuator, with the pinion being in the engaged position. 
     Thus, the time perceived by the user for the restarting of the internal combustion engine is reduced to the time for restarting the rotation of the said engine. 
     According to another embodiment of the method which is the subject of the invention, the engagement threshold is between 500 rpm and 300 rpm. Thus, the pinion of the launcher is systematically engaged, and the restarting takes place as soon as supply of fuel to the engine resumes, in particular as a result of the command by the accelerator. This functioning mode makes it possible to save fuel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described hereinafter according to its preferred embodiments, which are in no way limiting, and with reference to  FIGS. 1 to 9 , in which: 
         FIG. 1 , which relates to the prior art, represents in a view in cross-section of a common embodiment of an electric starter for an internal combustion engine; 
         FIG. 2  represents, according to a schematic view corresponding to the same cross-section as that in  FIG. 1 , an embodiment of the starter which is the subject of the invention, entirely at rest; 
         FIG. 3  is an electric flow diagram of an embodiment of an electric starter according to the invention, comprising an intermediate terminal between the input terminal and the output terminal; 
         FIG. 4  shows, according to the same view as  FIG. 2 , an embodiment of the starter which is the subject of the invention, in a configuration in which the auxiliary actuator and the main actuator are engaged; 
         FIG. 5  represents, according to the same view as  FIG. 4 , the starter which is the subject of the invention in a particular configuration where the actuators are disengaged, but the pinion of the launcher remains engaged with the crown of the crankshaft of the internal combustion engine; 
         FIG. 6  is a diagram showing on a time basis scenarios of deceleration of the internal combustion engine, with restarting of the engine by the electric motor of the starter which is the subject of the invention; 
         FIG. 7  shows, according to a partial front view, an embodiment of the auxiliary actuator according to the embodiment corresponding to  FIG. 3 , of the starter which is the subject of the invention; 
         FIG. 8  shows schematically, according to the same view as  FIG. 7 , an embodiment of the auxiliary actuator of a starter corresponding to the embodiment of the invention according to  FIG. 2 ; 
         FIG. 9 , represents according to the same view as  FIG. 8 , an alternative embodiment of the auxiliary actuator; 
         FIG. 10  represents, according to the same view as  FIG. 8 , an alternative embodiment of the auxiliary actuator; 
         FIG. 11  represents, according to the same view as  FIG. 8 , an alternative embodiment of the auxiliary actuator. 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment of a starter for an internal combustion engine which is the subject of the invention, in  FIG. 2  the starter comprises a control unit  210  comprising two contacts  211 ,  212 , closure of which supplies electrically actuators  220 ,  240  of a contactor  230 . The contactor  230  comprises a plunger  130 , the displacement of which is controlled by an actuator  220 , known as a main actuator. According to this embodiment, the plunger  130  is connected in translation to the pinion  160  of the launcher by means of a lever  260  and a pivot connection. The lever is supported on the housing of the starter according to a pivot connection and a translation connection perpendicular to the axis of rotation of the pivot connection, known as a sliding pivot connection  261 . The pinion can engage the crown  190  of the internal combustion engine. According to this embodiment, when the main actuator  220  is supplied with electrical energy (i.e., energized) by the closure of the corresponding contact  211  of the control module, the actuator gives rise to displacement of the plunger  130 , which plunger displaces a contact plate  231 , which contact plate can put a supply terminal  251  of an electric motor  150 , or output terminal, into electrical communication with a so-called power or input terminal  250  which is connected to an electrical energy source by a battery  100 , for example. The electric motor  150  is non-rotatably connected to the pinion  160  in one direction of rotation through the free wheel mechanism  165 . When it is supplied electrically, the electric motor  150  of the starter rotates the pinion  160  of the launcher. The contactor  230  also comprises an auxiliary actuator  240 , which, when it is supplied electrically (i.e., energized), can isolate the supply terminal  251  of the electric motor  150  from the input terminal  250 . The supply to this auxiliary actuator  240  is controlled by a second contact  212  of the control unit  210  of the starter. Thus, according to this embodiment, when the first  211  and the second  212  contacts of the control unit  210  of the starter are closed, the main actuator  220  and the auxiliary actuator  240  are supplied with electrical power (i.e., energized). The engagement of the main actuator  220  has the effect of giving rise to the displacement of the plunger  130 , which in this displacement drives the pinion  160  to the engaged position, whereas the engagement of the auxiliary actuator  240  isolates the electric motor  150  from the power supply  250 , such that the pinion  160  is not rotated, and does not drive the internal combustion engine  290 . On the basis of this situation, the opening of the second contact  212  of the control unit makes it possible to put the electric motor  150  into communication with the power source  100 , in this case an accumulator battery  100 , and gives rise to the rotation of the pinion  160  of the launcher, which drives the crown  190  of the internal combustion engine  290 . 
     According to one embodiment, in  FIG. 3 , the contact plate  331 , which is displaced by the plunger under the effect of the supply of the main actuator  220 , establishes the contact between the input terminal  250  connected to the accumulator battery, and an intermediate terminal  352 . According to this embodiment, the main actuator comprises a pull-in solenoid  321  and a hold-in solenoid  322 . The supply to the auxiliary actuator  240  by means of the closure of the second contact  212  of the control unit  210  displaces means  341 , which means, when the auxiliary actuator  240  is not supplied with power, establish electrical contact between the intermediate terminal  352  and the output terminal  251 . Thus, according to this embodiment, the auxiliary actuator  240  displaces live means  341 . 
     In  FIG. 4 , according to another embodiment, corresponding to that in  FIG. 2 , the contact plate  231  which is displaced by the plunger  130  establishes the contact between the input terminal  250  and the output terminal  251 , and the device which is controlled by the auxiliary actuator  240  spaces the said plate  231  from contact with one of these terminals, in this case the input terminal  250 , or prevents electrical contact between the said contact plate  231  and one of these terminals, in this case the input terminal  250 . Thus, the means  241  prevent contact between the plate  231  and one of the two terminals, in this case  250 , thus preventing the supply to the thermal engine. When the second contact  212  of the control unit is open, the auxiliary actuator  240  is no longer supplied with power and return means (not represented), for example in the form of a spring, or the force of the main actuator, displace(s) in the inverse direction the means  241  controlled by the auxiliary actuator  240 , thus closing the contact between the input terminal  250  and the output terminal  251 . The electric motor  150  is then supplied with power, and rotates the pinion  160  of the launcher. Advantageously, a sensor  410  measures the speed of rotation of the internal combustion engine  290 . Thus, when the said engine reaches a speed of rotation which is sufficient to ensure that it is started, for example 1500 rpm, the first contact  211  of the control unit is opened. The actuator  220  is no longer supplied with power, and return means (not represented) thrust the plunger  130  back, such that the contact space  231  is spaced from the terminals  250 ,  251 . The electric motor  150  is no longer supplied with power and stops, and the plunger  130 , which resumes its position of rest ( FIG. 2 ) spaces the pinion  160  from the crown  190 . 
     In  FIG. 5 , if, starting from the situation in  FIG. 4 , the two contacts  211 ,  212  of the control unit are opened simultaneously, then the contact plate  231  is spaced from the input  250  and output  251  terminals, and the plunger  130  and the means  241  for displacement of the auxiliary actuator  240  resume their position of rest ( FIG. 2 ) under the effect of their respective return means (not represented), and because of the rotation of the crown of the thermal engine. If at this moment the internal combustion engine  290  is at a standstill, the resistant torque of this engine prevents the extraction of the pinion  160  with helical toothing from being meshed with the crown  190 . The sliding pivot connection  261  of the lever  260  then allows the pinion to remain engaged with the crown, whereas the plunger is no longer retained in its active position by means of the forces generated by the solenoids, which are also known as the pull-in coil or hold-in coil. This therefore makes it possible to leave the pinion in the crown when the starter is no longer supplied electrically, i.e. with the contacts  211  and  212  open. Thus, the further closure of the first contact  211  of the control unit makes it possible to launch the internal combustion engine directly. According to this embodiment, the control unit  210  comprises memory means  511  in which there are recorded different threshold values of the speed of rotation of the engine. The control unit also comprises a computer  512  comprising an input port for the acquisition of information such as: 
     the speed of rotation of the internal combustion engine; 
     the state of control of the supply of fuel to the internal combustion engine; 
     the state of a start/stop contact of the engine. 
     The said computer  512  also comprises an output port to control the two contacts  211 ,  212  of the control unit separately. 
     In  FIG. 6 , on a time basis  600 , when the speed of rotation of the engine approaches a first threshold speed, known as the monitoring speed  611 , corresponding substantially to the idling speed of the said engine, for example 800 rpm, the computer of the control unit is on standby and monitors the successive events, in order to optimise the speed of restarting of the vehicle, according to scenarios recorded in the memory means. 
     Thus, for example, when the starter which is the subject of the invention is installed in a motor vehicle, in the case when the driver of the said vehicle releases the accelerator pedal, if the speed of rotation  620  of the internal combustion engine goes below a threshold, known as the first threshold  612 , for example 500 rpm, the internal combustion engine cannot restart by itself. On the other hand, if the speed of rotation of the said engine remains higher than this threshold, the restoration of the fuel supply to the engine allows it to restart. Thus, according to a first sequence of development  620  of the speed of rotation of the internal combustion engine, with the driver having released the accelerator pedal, the fuel supply is cut off, the speed of rotation  620  of the engine decreases, and after a first stage  601  the monitoring speed  611  is reached. The driver does not resume the acceleration, and at the end of a second stage  602 , the speed of rotation of the engine reaches the first threshold  612 . If, in a third stage  603 , the driver restarts the acceleration, with the computer of the control unit having received the information that the first threshold  612  has been passed, during this third stage  603  it closes the contact  211 , i.e. it closes the contact between the plate and the terminal  250  for the embodiment in  FIG. 4 , and closes the contacts between the terminals  250  and  251  for the embodiment in  FIG. 3 . Thus, the pinion of the launcher is engaged with the crown. When the speed of rotation of the internal combustion engine reaches a safety threshold  611 , the first contact  211  of the control unit is opened, which returns the plunger, disengages the pinion from the launcher, and stops the rotation of the thermal engine. 
     According to another scenario  621  of development of the speed of rotation of the engine, the driver does not re-accelerate, and the speed of rotation of the internal combustion engine goes below a third threshold  613 , known as the engagement threshold, for example 50 rpm. In these conditions, when this threshold  605  has been exceeded, the computer closes the two contacts  211  and  212  of the control unit, which has the effect of engaging the pinion with the crown. The introduction of the said pinion at this lower speed of rotation limits the wear of the said pinion. When there is a starting request, for example when the driver re-accelerates, or the contact  210  is engaged, the process opens the contact  212 , which permits very rapid restarting during the balancing phase. According to a preferred embodiment, during the balancing phase, i.e. when the engagement threshold has been exceeded, after a time δt necessary in order to ensure that the pinion is engaged in the crown, the computer opens the second contact, which has the effect of rotating the electric motor of the starter, and restarting the internal combustion engine. 
     When the thermal engine is at a standstill, i.e. when the crankshaft of the thermal engine is at a standstill, then the two contacts of the control unit are opened, and the pinion continues to be engaged with the crown when the vehicle stops. 
     In  FIG. 7 , according to an embodiment of the auxiliary actuator corresponding to the embodiment represented in  FIG. 3  of the starter which is the subject of the invention, the means  341  is displaced by a micro-solenoid  740 , and returned to position by a helical spring  741  which forms a return means. 
     In  FIG. 8 , according to an embodiment of the auxiliary actuator corresponding to the embodiment in  FIG. 2  of the starter which is the subject of the invention, a micro-solenoid  240  commands the displacement of a ring  841  which is substantially concentric relative to the output terminal  251 . The contact plate  831  is displaced in translation towards the terminals  251 ,  250  by the plunger  130 , and is articulated according to a pivot connection  832  with an axis substantially perpendicular to the said direction of displacement in translation, for example by means of play between a hole in the plate  831  and a control rod which displaces the plate which passes through this hole. When power is supplied to the micro-solenoid  240 , the ring  841  prevents the said contact plate  831  from being in contact with the output terminal  251 , or spaces the plate  831  from the terminal  251 . When power is no longer supplied to the micro-solenoid  240  of the auxiliary actuator, return means  842  thrust back the ring  841 , which then permits contact of the plate  831  with the output terminal  251 . According to this embodiment, the ring comprises a part which is preferably metal, in order to be able to be displaced by the micro-solenoid, but the end of the ring  841  which is in contact with the contact plate  831  is electrically isolated. 
     According to another embodiment represented in  FIG. 10 , when power is supplied to the micro-solenoid  240 , the ring  1041  in the activated position prevents the said contact plate  831  from being in contact with the output terminal  251 . When power is no longer supplied to the micro-solenoid  240  of the auxiliary actuator, by means of the plunger  130  and the plate  831  the main actuator thrusts the ring  1041  into the deactivated position, which then permits contact of the plate  831  with the output terminal  251 . According to this embodiment, the micro-solenoid  240  preferably comprises a spring  1042  to return the ring  1041  to the activated position, firstly in order to ensure that the ring prevents contact between the plate  831  and the output terminal  251 , and secondly in order to attenuate the vibrations in the state of rest. In an identical manner, the ring comprises a part which is preferably metal, in order to be able to be displaced by the micro-solenoid, but the end of the ring  1041  which is in contact with the contact plate  831  is electrically isolated. 
     In  FIG. 10A , the ring  1041  is thrust towards the contact plate  831  by a spring  1042  and the action of the micro-solenoid  240 , thus spacing the said plate  831  from contact with the output terminal  251 . In  FIG. 10B , since power is no longer supplied to the micro-solenoid  240 , the action of the plunger  130  thrusts the ring  1041  back, thus compressing the springs  1042 , and permitting closure of the contact between the input terminal  250  and the output terminal  251 . 
     According to another example of the two embodiments previously described, the auxiliary actuator does not comprise its ring around the input terminal, but around the output position. In this embodiment, the ring prevents contact between the plate and the input terminal. 
     In  FIG. 9 , according to another embodiment of the auxiliary actuator corresponding to the embodiment in  FIG. 2  of the starter which is the subject of the invention, a micro-solenoid  240  commands the displacement of a ring  941 , which is placed between the input terminal  250  and the output terminal  251 . Under the action of the solenoid  220  of the main actuator, the plunger displaces the contact plate  931  in translation towards the said terminals  250 ,  251 . The said contact plate  931  comprises a degree of freedom in translation parallel to the direction of displacement of the plunger, and return means  932  which tend to thrust the contact plate towards the terminals  251 ,  252 . The power supply to the micro-solenoid  240  of the auxiliary actuator prevents the contact plate  931  from being in contact with the terminals  250  and  251  by means of the ring  941 . When the supply to the said micro-solenoid is cut-off, return means  942  give rise to withdrawal of the ring  941 , and the return means  932  of the contact plate  931  thrust the said plate into contact with the terminals. Thus, according to this embodiment, the ring  941  is not in contact with the plate  931  when the latter is in contact with the input terminal. 
     According to another embodiment represented in  FIG. 11 , when power is supplied to the micro-solenoid  240 , the ring  1141  in the activated position prevents the said contact ring  831  from being in contact with the terminals  251  and  250 . When power is no longer supplied to the micro-solenoid  240  of the auxiliary actuator, by means of the plunger  130  and the plate  931  the main actuator thrusts the ring  1141  into the deactivated position, which then permits contact of the plate  931  with the two terminals  251  and  250 . According to this embodiment, the micro-solenoid  240  preferably comprises a spring  1142  to return the ring  1141  to the activated position, firstly in order to guarantee that the ring prevents contact between the plate  931  and one or both terminals  250 ,  251 , and secondly in order to attenuate the vibrations in the state of rest. In this embodiment, in the deactivated position, the ring is in contact with the plate. The ring comprises a part which is preferably metal, in order to be able to be displaced by the micro-solenoid, but the end of the ring  841  which is in contact with the contact plate  831  is electrically isolated. 
     In a similar manner, in  FIG. 11A , when power is supplied to the micro-solenoid  240 , its action is added to that of the spring  1142 , and thrusts the ring  1141 , which spaces the contact plate  931  from the terminals. In  FIG. 11B , when power is no longer supplied to the micro-solenoid  240 , the action of the plunger  130  thrusts the ring  1141  back, thus compressing the spring  1142 . 
     The embodiments represented in  FIG. 10  and  FIG. 11  have the advantage that, in the absence of an electrical supply, the action of the springs  1042 ,  1142  acting on the auxiliary actuator  1041 ,  1042  tends to open the contact between the terminals. Thus, in the starting sequence of the engine, the auxiliary actuator is by default in the configuration designed for concatenation of the steps, such as to reduce the starting time further still. 
     The foregoing description and the examples of embodiments show that the invention achieves the objectives set out. In particular, it makes it possible to reduce the restarting time of an internal combustion engine, by pre-engaging the pinion of the launcher whilst the said combustion engine is still rotating.