Abstract:
A device for driving a regulation valve for casting liquid metal contains a main rod controlling the opening and closing of the valve, and a coupler linking the main rod and the valve. The device also contains a coupler controller able to activate and deactivate the coupler, enabling linkage and detachment of the main rod and the valve.

Description:
BACKGROUND OF THE INVENTION 
     a) Field of the Invention 
     The present invention concerns the technical field of the continuous casting of liquid metal, for example liquid steel. 
     b) Description of the Related Art 
     In a liquid metal casting installation, the liquid metal is generally transferred from a pouring ladle to a distributor, intended to distribute the liquid metal in casting moulds. In order to transfer the liquid from the ladle to the distributor, a regulation valve is generally used, disposed at the bottom of the pouring ladle. This regulation valve, referred to as a “slide valve”, is generally composed of two superimposed plates, sliding one with respect to the other so that the valve can take a closed configuration, during which the pouring ladle can be moved, and an open configuration, allowing liquid to pass for transfer thereof into the distributor. To provide the opening and closing of the regulation valve, a device is used for driving the valve, attached to the pouring ladle or to the valve, when the pouch arrives close to the distributor. 
     An example of a driving device is described in the document U.S. Pat. No. 6,045,015. This driving device comprises a hydraulic actuator, provided with a cylinder temporarily fixed to the valve. The end of the rod of the actuator is also coupled to one of the plates of the valve, to open or close it. For this purpose, the end of the rod comprises a coupling jaw in which one end of the moving part of the valve containing the moving plate snaps. 
     Thus, in order to mount the driving device on the valve, the cylinder of the actuator is first of all attached to the valve, and then the actuator rod and plate are coupled by moving the actuator rod in one direction, hereinafter referred to as the longitudinal direction. Later, at the end of the casting operations, in order to remove the driving device from the valve, the end of the moving plate of the jaw is withdrawn by effecting a sliding of the entire driving device (and therefore of the jaw) in a transverse direction, perpendicular to the longitudinal direction. Thus, as the driving device must be demounted by moving in the transverse direction, it is necessary to provide sufficient space under the pouring ladle for implementation thereof. 
     However, the bottom part of the pouring ladle is generally very encumbered, for example by reinforcements, feet of the ladle, arrangements for injecting bubbles in the bottom of the ladle, pipes, etc. As a result the step of demounting the driving device poses difficulties. 
     BRIEF SUMMARY OF THE INVENTION 
     The aim of the present invention is to propose a driving device, the mounting and demounting of which is simpler to implement. 
     To this end, a subject matter of the invention is a device for driving a regulation valve for casting liquid metal, comprising a main rod controlling the opening and closing of the valve, and a valve—main rod coupler (being a means of coupling the main rod to the valve), characterised in that it also comprises a coupler controller (being a means of controlling the coupling means), able to active and deactivate the coupling means. 
     Thus, rather than having to move the driving device in the transverse direction in order to decouple the valve, it is proposed to perform first of all a step of deactivating the coupling means, causing them to resume their initial configuration, and then to proceed with the demounting of the driving device. This demounting is thus simplified since it is no longer necessary to provide a transverse movement, in addition to the longitudinal movement performed for the coupling, for the specific demounting of the coupling means. Consequently it is no longer necessary to leave clear as large a space as previously under the pouring ladle. 
     Moreover, as the deactivation of the coupling means is controlled, this operation can be done at a distance, so that human intervention is not necessarily necessary for demounting the coupling means. This simplifies the operation since human intervention is generally tricky to implement because of the high level of heat in the bottom part of the ladle after pouring. In addition, controlling the activation or deactivation offers the possibility of completely automating the coupling and decoupling of the driving device with the regulation valve. In particular, it may be difficult to completely automate this coupling and decoupling when the movements must follow both a longitudinal direction and a transverse direction. 
     It should also be noted that the control means proposed make it possible to more easily control the opening and closing of the valve. This is because, when the valve is not coupled to a driving device, there exists a risk of accidental opening of the valve, for example following an impact during the movement of the pouring ladle. However, accidental opening during movement may cause considerable damage when the pouring ladle is filled with very hot liquid metal. To reduce this risk, providing the valve with a system for locking the valve in the closed position is known in the prior art. The valve then needs to be released before beginning the pouring operations. According to the invention, this release may advantageously be activated by the means of controlling the coupling means at the time of coupling of the valve. 
     The driving device can also comprise one or more of the following features.
         The means of controlling the coupling means comprise a coupling piston connected to a coupling rod, the end of the coupling rod being able to activate and deactivate the coupling means by sliding of the piston and coupling rod.   The coupling rod is slidably mounted inside the main rod. Apart from the fact that it is thus if necessary possible to optimise the number of hydraulic connections of the driving device, providing the coupling rod in the main rod reduces the size of the driving device.   The coupling means comprise at least one stud attached to the main rod, mounted so as to be able to move with respect to the main rod between an activated position, in which the stud extends transversely to the main rod while projecting from this rod so as to be able to couple the main rod and the valve, and a deactivated position, in which the stud is at least partially retracted in the main rod, so as to be able to decouple the main rod and the valve. Thus, when the stud is in the activated position, the projection produced on the main rod can allow anchoring of this rod in a corresponding housing in the regulation valve.   The end of the main rod is intended to be received in a housing in the valve, the stud comprising a stop surface arranged to hold this end in the housing when the stud is in the activated position. In other words, the stud, in the activated position, provides a function of anchoring the end of the main rod in the valve housing. By virtue of this housing, any movement of the main rod gives rise to a similar movement of the valve housing, and therefore of one of the plates of the regulation valve, for opening or closing thereof.   The driving device comprises a coupling return (being a means of returning the coupling means to their deactivated position). It is possible for example to provide an arm driving the coupling means, able to be actuated by a spring, or by the coupling rod.   The driving device comprises a cylinder or driving device exterior casing intended to be received in a valve exterior housing, the device comprising a piston, referred to as the main piston, connected to the main rod, and comprising another piston, referred to as the fixing piston, arranged to fix the cylinder or driving device exterior casing relative to the valve exterior housing. It should be noted that the valve exterior housing can be provided directly on the regulation valve, or on the pouring ladle on which the regulation valve is mounted. This embodiment is particularly advantageous for facilitating the mounting of the cylinder or driving device exterior casing in the housing. This is because, in order to fix the cylinder or driving device exterior casing in the valve exterior housing, it is generally necessary to embed it in the valve exterior housing, reducing as far as possible the clearances between the cylinder and the valve exterior housing in order to prevent pressure drops. Because of this tight embedding, mounting of the cylinder or driving device exterior casing in the valve exterior housing may be relatively difficult to implement, particularly by a robot. By providing a second piston fixing the cylinder or driving device exterior casing to the valve exterior housing, it is possible to fix the cylinder whatever the size of the valve exterior housing in which it is received. This is because, by virtue of the fixing piston, it is possible to adjust the size of the cylinder once the latter is attached in the valve exterior housing, so as to eliminate or reduce clearances. In other words, according to a first step, the cylinder or driving device exterior casing can be introduced into the valve exterior housing, allowing the presence of a clearance, and, in a second step, the clearance can be compensated for, by moving the fixing piston, in order to make this clearance disappear. By making this clearance disappear, a pressure drop is avoided during the travel of the main piston, while allowing automation of the mounting of the cylinder or driving device exterior casing on the valve.   The device comprises a hydraulic chamber delimited on the one hand by the main piston and on the other hand by the fixing piston. Thus the fixing system can be provided without for all that requiring a complex structure for the driving device. In particular, it is not necessary to provide four distinct chambers for controlling the main piston and the fixing piston since a common hydraulic chamber is used for maneuvering the main piston and fixing piston.   The fixing piston has the main rod passing through it.   The means of controlling the coupling means comprise a coupling piston connected to a coupling rod, and the driving device is configured so that the main piston, the fixing piston and the coupling piston can be controlled by a control unit by means of three hydraulic connections to the unit, namely: a first connection between the unit and the hydraulic chamber delimited by the main piston and the fixing piston, a second connection between the unit and a hydraulic chamber delimited by the main piston and the cylinder, and a third connection between the unit and a channel connecting both a hydraulic chamber delimited by the fixing piston and the cylinder and a hydraulic chamber delimited by the coupling piston and the cylinder. This embodiment is particularly advantageous: only three connections to the control unit are used to control the movement of three distinct pistons, where it would have been possible to use six connections, namely two per piston. The device proposed is therefore particularly compact and does not require any expensive and complicated connection.   A return means is disposed around the main rod, under the head of the main piston. This return means can take the form of an elastic washer. It makes it possible to move the head of the main piston away and allows the injection of hydraulic fluid, thus preventing any risk of blocking.   The valve can be locked in the closed position, and the means controlling the coupling means also control means of locking the valve. Thus, by locking the valve, it is guaranteed that it does not risk opening during the movement of the pouring ladle. In addition, the same control means can control both the coupling means and the means of locking the valve.       

     Another subject matter of the invention is the assembly consisting of a driving device as described above and a regulation valve, also comprising a guidance element, comprising a housing receiving part of the driving device, a housing receiving part of the valve, and means of guiding the coupling means during movement thereof. 
     Another subject matter of the invention is a device for mounting and demounting a driving device as described above on a regulation valve and/or on a pouring ladle, arranged to ensure the automatic mounting and demounting of the driving device. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The invention will be better understood from reading of the following description, given solely by way of example and made with reference to the accompanying drawings, in which: 
         FIGS. 1 a  and 1 b    are views in section of a driving device according to one embodiment, comprising coupling means respectively in the deactivated position and in the activated position; 
         FIGS. 2 a  to 2 f    are schematic views in section illustrating the steps of functioning of a driving device similar to the one in  FIGS. 1 a    and  1   b;    
         FIG. 3  is a perspective view in section of the end of a main rod of a driving device similar to the one in  FIGS. 1 a    and  1   b;    
         FIGS. 4 a  and 4 b    are views in schematic section of a driving device similar to the one in  FIGS. 1 a  and 1 b   , assembled on a guidance element; and 
         FIG. 5  is a view in partial section of a driving device similar to the one in  FIGS. 1 a  and 1 b   , illustrating the hydraulic connections of this device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A casting installation generally comprises a distributor, for distributing liquid metal to casting moulds. This distributor is supplied with liquid metal by means of pouring ladles, movable above the distributor in order to provide this transfer. Each pouring ladle is provided with a valve regulating the pouring, often composed of a linear valve, referred to as a “slide valve”. The opening or closing of this regulation valve is controlled by a driving device  10 , shown in particular in  FIGS. 1 a  and 2 a   . Generally this driving device comprises a cylinder or casing or driving device exterior casing  12 , intended to be at least partially received in a housing  14  integral with the valve, mounted fixed in this valve exterior housing  14 . This valve exterior housing  14  can be directly provided on the regulation valve, or on the pouring ladle on which the regulation valve is mounted. Moreover, the driving device  10  comprises a main rod  16  controlling the opening and closing of the valve, slidably mounted in the cylinder or driving device exterior casing  12 , the end  18  of which is intended to be received in a housing  20  in the valve in order to be coupled to the latter. More precisely, the housing  20  in the valve is provided on a moving part  13  of the valve. In the case of a slide valve provided with two superimposed plates sliding one with respect to the other, the housing  20  is provided on the part  13  of the valve receiving the moving plate, the movement of the end  18  once coupled to the housing  20  making it possible to move this plate between a closed position and an open position of the valve. 
     The driving device  10  is provided with a first piston  22 , referred to as the main piston, slidably mounted in the cylinder  12  and connected to the main rod  16  so that any movement of the piston  22  is transmitted to this main rod  16 . The movement of this piston  22 , and therefore of the main rod  16 , opens or closes the regulation valve. As can be seen in  FIG. 1 a   , or in  FIG. 2 d   , the main piston  22  delimits, with the inside of the cylinder  12 , first  24  and second  26  main hydraulic chambers. The first main chamber  24  is supplied with fluid by a supply channel  28 , and the second main chamber  26  is supplied with fluid by a supply channel  30 , as shown in  FIG. 5 . As can be seen in  FIG. 1 a   , a return means  29  is disposed around the main rod  16 , under the head of the main piston  22 . This return means is for example an elastic washer. It moves away the piston head  22  and allows the injection of hydraulic fluid in the chamber  26 , even when the piston  22  is at the end of travel. 
     In addition, in order to fix the cylinder  12  in the housing  14 , integral with the valve, the driving device  10  comprises a second piston  32 , referred to as the fixing piston. This piston  32  is arranged to bear on a wall  34  of the housing  14 , as can be seen in  FIG. 2 c   , so as to lock by clamping the cylinder  12  with respect to the housing  14 . More precisely, the second piston  32  comprising a skirt  33  intended to form a shim between the cylinder  12  and the wall  34  of the housing  14 . The fixing piston  32  and the wall  34  of the housing  14  have the main rod  16  passing through them, so as to allow this rod  16  to slide under the effect of the movement of the piston  22 . As can be seen in particular in  FIG. 2 b   , the piston  32  delimits, with the cylinder  12 , on the one hand the second main hydraulic chamber  26  and on the other hand a third hydraulic chamber  36 , disposed in the front part of the cylinder (the front direction being indicated by the arrow X in  FIG. 2 a   ). Thus the second hydraulic chamber  26  is delimited on the one hand by the main piston  22  and on the other hand by the fixing piston  32 . A common chamber is therefore used for acting on the two pistons, whence a saving in space. The third hydraulic chamber  36  is supplied with fluid by a supply channel  38 , shown in  FIG. 5 . 
     The driving device  10  also comprises a valve—main rod coupler  40  (or means  40 ) of coupling the main rod  16  to a moving part  13  of the regulation valve, or more precisely coupling the end  18  of the rod  16  with the housing  20  in the valve. In this example, the coupling means comprise two studs, attached to the main rod  16 , mounted so as to be able to move with a respect to the rod  16  between an activated position shown in particular in  FIG. 2 d   , in which the studs extend transversely to the main rod  16  while projecting from this rod so as to be able to couple the main rod  16  and the moving part  13  of the valve, and a deactivated position, shown in particular in  FIG. 2 a   , in which the studs are at least partially retracted in the main rod  16 , so as to be able to decouple the main rod  16  and the moving part  13  of the valve. More precisely, when they are in the deactivated position, the maximum diameter of the end  18  of the rod  16  is less than height H of an opening in the housing  20 , as can be seen in  FIG. 2 a   . Thus, in the deactivated position of the studs, the end  18  can pass inside the housing  20 , from the position illustrated in  FIG. 2 a    as far as the position illustrated in  FIG. 2 b   . To facilitate this passage of the end  18  inside the housing  20 , that is to say to prompt the studs to adopt their deactivated position, a bevelled surface  42  can be provided in front of the studs. Moreover, the studs each comprise a stop surface  44 , arranged to hold the end  18  of the rod  16  in the housing  20  when the studs are in the activated position. This stop surface  44  cooperates with a stop surface  46  provided in the housing  20 . 
     The end  18  also comprises a coupling return  50  (or means  50 ) configured to return the coupling means  40  to the deactivated position, visible in particular in  FIGS. 1 a , 1 b    and in  FIG. 3 . These means  50  comprise two arms each mounted pivotally about an axis  52 , each comprising an end  54  cooperating with the studs, cooperating with a recess  56  provided in the front wall of the studs, and an activation end  58  described more precisely hereinafter. 
     The driving device  10  also comprises coupler controller  60  (or means  60 ) configured to control the coupling means  40 , and able to activate and deactivate them. These means  60  comprise a coupling piston  62 , connected to a coupling rod  64 , the end  66  of which, opposite to the piston  62 , is able to activate and deactivate the coupling means  40 , by sliding. More precisely, the end  66  of the rod  64  is splayed. It has a rear surface  68 , able to form a ramp with the studs so as to make them pass into their activated or deactivated position when the rod  64  slides, as described hereinafter. Moreover, the end  66  has a front part  69  comprising a substantially flat surface configured to come into abutment against the bottom of the housing  20 . Moreover, the front part  69  is arranged to cooperate with the end  58  of the arms, so as to return the coupling means  40  into the deactivated position, as described hereinafter. 
     The coupling rod  64  and the coupling piston  62  are mounted slidably inside the main rod  16  of the device  10 . More precisely, as can be seen in  FIG. 1 a   , the piston  62  delimits, with the main rod  16 , fourth  70  and fifth  72  hydraulic chambers for moving the piston  62  inside the main rod  16  under the action of a fluid. The rear hydraulic chamber  70  is supplied with fluid by virtue of a channel  74 , shown in  FIG. 5 . Moreover, the front hydraulic chamber  72  is supplied with fluid by virtue of a passage  76  communicating with the second main hydraulic chamber  26 . Thus, like the chamber  26 , it is through the channel  30  that the front chamber  72  is supplied with fluid. 
     The hydraulic connections of the driving device  10  to a control unit  81  will now be described. The device  10  is configured so that the main piston  22 , the fixing piston  32  and the coupling piston  62  can be controlled by the control unit  81  by means of three hydraulic connections  77 ,  78 ,  79 , namely:
         a first connection  77  between the unit  81  and the hydraulic chamber  26  delimited by the main piston  22  and the fixing piston  32 ,   a second connection  79  between the unit  81  and the hydraulic chamber  24  delimited by the main piston  22  and the cylinder  12 , and   a third connection  78  between the unit  81  and the channel connecting both the hydraulic chamber  36  delimited by the fixing piston  32  and the cylinder  12 , and the hydraulic chamber  70  delimited by the coupling piston  62  and the cylinder  12 . It will therefore be noted that the supply channels  74  and  38  are connected to each other.       

     The mounting of the driving device  10  on a pouring ladle will now be described with reference to  FIGS. 2 a    to  2   f.    
     Generally the driving device  10  is installed on a pouring ladle when this pouring ladle is in an intermediate position, a position for example during which another pouring ladle is in the process of being emptied into the distributor. When the pouring ladle arrives in this intermediate position, it is filled with liquid metal and the regulation valve is closed. The driving device  10  is then attached under the ladle, in the immediate vicinity of or very close to the valve. The mounting of the device  10  commences with introduction of the cylinder or driving device exterior casing  12 , or at least a front part  80  of the cylinder or driving device exterior casing  12 , in the valve exterior housing  14 , in the configuration illustrated in  FIG. 2 a   . In this configuration, the fixing piston  32  is in the retracted position in the cylinder or driving device exterior casing  12 , that is to say the chamber  36  has a substantially maximum volume. Thus the piston  32  and the skirt  33  do not project from the cylinder or driving device exterior casing  12 , or only a little, so that the length of the cylinder or driving device exterior casing  12  is relatively short. As a result the part  80  of the cylinder or driving device exterior casing  12  can easily be inserted in the valve exterior housing  14 , by virtue of a clearance  82 . At the time of this insertion of the cylinder or driving device exterior casing  12  in the valve exterior housing  14 , the supplies to the hydraulic chambers  24 ,  26 ,  36 ,  70 ,  72  are in the neutral position, that is to say the pistons  22 ,  32  and  62  are immobile. In this configuration, the main piston  22  (and therefore the main rod  16 ), just like the fixing piston  32 , is in the retracted position inside the cylinder or driving device exterior casing  12 , and hence there is a certain compactness of the device  10  at the time of fixing of the cylinder or driving device exterior casing  12  on the valve. The coupling piston  62  and the coupling rod  64  are for their part in the deployed position, the splayed end  66  arriving substantially flush with the end  18  of the main rod  16 , and the coupling means  40  being in the deactivated position, as illustrated in  FIG. 1   a.    
     Once the cylinder  12  is disposed inside the housing  14 , fluid is injected through the channel  28 , so as to move the main piston  22  towards the front X ( FIG. 5 ). Because of this movement, the main rod  16  also moves in the forward direction, and its end  18  passes inside the housing  20 , as illustrated in  FIG. 2 b   , until the end  18  arrives in abutment in the bottom of the housing  20 . Once the end  18  is in abutment in the housing  20 , fluid is injected into the second hydraulic chamber  26 , through the channel  30 , while preventing fluid being able to emerge from the channel  28 . This injection of fluid through the channel  30  has two effects. This is because the increase in liquid inside the chamber  26  moves the fixing piston  32  forwards, so that the skirt  33  projects outside the part  80  of the cylinder  12  and comes into abutment against the wall  34  of the housing  14 , which has the effect of clamping the cylinder in the housing  14  and therefore locking it. Simultaneously (or a little after, or a little before), the passage of liquid in the chamber  26  makes it possible, by virtue of the passage  76 , to increase the quantity of fluid inside the front chamber  72 , and therefore to move the coupling piston  62  towards the rear, so as to make the coupling rod  64  retract with respect to the rod  16 , as shown in  FIG. 2 c   . Because of this movement of the coupling rod  64 , the end  66  retracts inside the end  18 , which moves the coupling means  40  from their deactivated position to their activated position. In other words, the studs emerge from the end  18 , by ramp effect. 
     Once the fixing piston  32  is in the position of fixing the cylinder in the housing  14 , and the coupling rod  64  is in the retracted position in the rod  18 , in order to activate the studs, the channel  28  is unblocked, while continuing to inject fluid into the channel  30 . As a result the main piston  22  moves towards the rear, so as to make the end  18  of the main rod  16  retract slightly. As a result the walls  44  of the studs come into abutment against the walls  46  of the housing  20 . In this position, the valve and the driving device  10  are coupled. The valve can therefore be opened or closed, by movement of the main piston  22  in the cylinder  12 , by virtue of the injection of fluid through the channel  30  or through the channel  28 . Thus, in the configuration illustrated in  FIG. 2 d   , when the main piston  22  retracts in accordance with the arrow  84 , it drives the valve, or more precisely one of the plates of this valve, in order to open the valve. In the configuration illustrated in  FIG. 2 e   , when the piston  22  is moved forward, in accordance with the arrow  86 , it closes the valve. 
     When it is wished to demount the driving device  10  from the pouring ladle, the following procedure is adopted. First of all the valve is closed, by disposing the piston  22  as shown in  FIG. 2 f   . Fluid is then injected into the channels  38  and  74 , which has the dual effect of moving the piston  34  towards the rear, and therefore releasing the cylinder  12  with respect to the housing  14 , and moving the piston  62  forwards, therefore putting the blocking means  40  back in the deactivated position. It should be noted that, when the end  66  advances forwards, it cooperates with the end  58  of the arms, which pivots their end  54  towards the centre and therefore returns the studs to the deactivated position. In this deactivated position of the studs, it is possible to withdraw the end  18  from the housing  20 , possibly previously having moved the piston  22  towards the rear, and then easily removing the driving device from the housing  14 . 
     According to one advantageous embodiment, illustrated in  FIGS. 4 a  and 4 b   , the valve can be locked in the closed position, which prevents the risks of accidental opening during movement thereof. To this end, valve locking device  90  and valve unlocking device  92  (being locking and unlocking means  90 ,  92 ) are provided, comprising a latch cooperating with a slot provided on the valve, in the housing  20 . This latch is returned to the locked position by virtue of a spring  94 . The latch is carried in this example by a guidance element  96 , mounted fixed with respect to the pouring ladle and with respect to the fixed part of the regulation valve, forming a kind of extension of the valve. This element  96  carries a housing  14  for the cylinder, similar to the one described previously, and also comprises a valve—main rod coupler guide, or rail,  98  for guidance of the movable part  13  of the valve, in which the housing  20  of the moving part  13  can slide. 
     The means  62 ,  64  of controlling the coupling means  40  advantageously control the unlocking means  90 ,  92 . This is because, before the coupling between the device  10  and the moving part  13  of the valve is implemented, the latter is in the locked position, illustrated in  FIG. 4 a   . Then, once the cylinder or driving device exterior casing has been introduced into the valve exterior housing  14  and the main rod  16  inside the housing  20 , the movement of the studs, under the effect of the sliding of the coupling piston  62 , gives rise to a movement of the locking means  90 , from their locked position to their unlocked position, illustrated in  FIG. 4 b   . More precisely, the bevelled surface  42  cooperates with a bevelled surface of the latch  92  in order move it upwards in order to make it leave the slot  92  and thus release the moving part  13  of the valve. Moreover, when the device  10  is demounted, advantageously also, when the studs pass into the deactivated position and the valve is closed, the latch is once again placed in the slot, under the effect of the means  94 , which locks the valve in the closed position. 
     It will be understood that the method described above can easily be automated. Thus it is possible to provide a robot for mounting and demounting the device  10 , arranged to provide the automatic mounting and demounting of the device  10 . 
     It should be noted that the invention is not limited to the embodiment described above. 
     Among the variants of the driving device, it should be noted that the means  50  of returning the coupling means into the deactivated position may not be actuated by the coupling rod  64  but comprise springs, for example acting on the studs so that they resume their deactivated position. 
     A person skilled in the art will easily be able to transpose this teaching to any device used in the continuous casting of a metal actuated by an actuator that has to be attached at the time of use thereof, such as for example a device for changing pouring tube, a distributor slide, a device controlling a stopper rod, etc. 
     Numerous modifications and variations of the present invention are possible. It is, therefore, to be understood that within the scope of the following claims, the invention may be practiced otherwise than as specifically described.