A fairlead for fitting a towing device which can be installed on the deck of a ship and to tow an object dragged behind the ship. The towing device conventionally comprises a winch, a cable and a fairlead, the cable passing through the fairlead under the action of the winch. This type of device is for example used in the field of underwater acoustics and particularly for towed active sonars. These sonar typically include an integrated transmit antenna in a submersible object, or "fish" and a receiving antenna comprised of a linear antenna or "flute". When using the towing sonar, fish and flute are sotidaires the same cable to be towed (e ship.

It is possible to use the sonar in passive mode, that is to say without its transmit antenna or active mode with its transmit antenna formed by the fish and its receiving antenna. To ensure these two modes of operation the fish is secured and removably connected to the cable. When the fish is in place on the cable, it is suspended from the cable so that its center of gravity is located below the axis of the cable. The fish has a body and one or both arms. The free end of each arm is hooked on the first cable over the cable to enable the cable guide in the fairlead.

The cable typically includes a core formed of electric conductors and / or optical for transmitting energy and information between the sonar equipment located on board the ship and antennas. The cable core is usually covered with a metal strand son of ensuring your mechanical strength of the cable. The constitution of the cable imposes a minimum bend radius. Below this radius, unacceptable mechanical stresses occur and drive a damage to the cable components. The winch mounted on the deck has a reel on which the first cable can be wound when the sonar is inactive and that the antennas are arranged on the ship.

When your items are towed out to sea, the cable is guided by first fairlead that secures the actual bend radius. The fairlead is the last cable guide member relative to the vessel before the descent of the cable in the water. The fairlead includes a frame secured to the deck and a channel in which the cable slides. The channel has an open cross-section from above so that the cable is held in the channel by gravity. When the sea is rough or in ship handling, the cable can come out of the channel, the fairlead then not completing its role as guide. To avoid that the cable exits the channel, it is desirable to close at least one section of the channel. But to close the channel prevents the arms of fish pass through the fairlead.

The plaintiff tried to internally perform a fairlead with a closed section that an operator can manually open arms to let the fish. The position of the fairlead in the stern or partly overlooking the stern of the ship makes the opening maneuver and closing tricky or even dangerous in difficult navigation conditions. The offset commands for opening and closing the fairlead would be possible but difficult to implement. In addition, the towing device already requires an operator rotating the winch. If this operator had to move to maneuver the opening of the fairlead, this could leave it open fairlead for too long. A second operator can maneuver the fairlead which generates a cost

The invention solves this problem by providing a closed channel fairlead can be opened automatically during the passage of fish.

To this end, the invention relates to a fairlead for fitting a towing device can be installed on the deck of a ship and comprising a winch, a cable passing through the fairlead under the action of the winch, the cable gland comprising :

• an open channel section extending in a main direction for guiding the cable,

• a mobile bolt closing a section of the channel,

• a force sensor located in front of the bolt in a direction carried by the main direction and configured to detect an external force, and

• a shutter configured to open the bolt when a force exerted on the sensor and oriented along the main axis in the direction exceeds a predetermined force and to close the latch when this force disappears.

Advantageously, the force sensor is configured to detect an external force in front of the bolt back and forth carried by the main direction and the shutter is configured to open the bolt when a force exerted on the sensor and oriented along the axis main in both directions beyond the predetermined force and to close the latch when this force disappears.

According to a first embodiment of the invention, the bolt is rotatable relative to the channel about an axis of rotation substantially perpendicular to the main direction.

Advantageously, according to the first embodiment, the force sensor comprises a movable flap rotatably about the axis of rotation. The shutter comprises a pawl which can assume two positions, a first position, called the closed, is effective without effort on the tongue and holds the bolt closed and a second position, said open, allows free rotation of the bolt. The pawl is driven by the tongue from the closed position to the open position after passing the predetermined force, the fairlead further comprising a first spring coupled between the channel and the tongue, the stiffness of the spring part in the predetermined force and realignment of the bolt with the tongue.

The first spring may be prestressed, the prestressing participating in the predetermined force, and the realignment of the bolt with the tongue.

Advantageously, according to the first embodiment, the trigger comprises a second spring tending to close the bolt, the second spring being connected in series with the first spring. The bolt is secured to the common point between the two springs.

The second spring advantageously has a lower stiffness than the first spring.

The second spring may be pretensioned to a value smaller than the first spring.

According to a second embodiment of the invention, the bolt is movable in translation relative to the channel in a substantially perpendicular to the main direction axis.

Advantageously, according to the second embodiment, the force sensor includes a movable tab to rotate about an axis of rotation substantially perpendicular to the main direction and means for converting a rotational movement of the tongue in translation of the bolt. These means are preferably irreversible.

Advantageously, the fairlead of the second embodiment comprises a cam rotating with the tongue and a pivotable lever including at a distance from its pivot axis, a pin supported on the cam and a groove into which the bolt rests.

The fairlead preferably comprises a return spring tending to return the cam to a position of equilibrium in which the bolt is closed.

The invention also relates to a towing device which can be installed on the deck of a ship and comprising a winch, a cable and a cable gland according to the invention, the fairlead and the winch being fixed relative to the 'other.

The invention will be better understood and other advantages will appear on reading the detailed description of an embodiment given as an example, description illustrated by the attached drawing in which:

1 shows schematically a vessel towing an active sonar;

2 shows more precisely a trailer coupling attached to the ship's deck;

3 shows a fairlead wherein passes a fish;

Figure 4 shows in perspective a first embodiment of an automatic opening mechanism of the fairlead;

thy 5a, 5b and 5c represent the profile fairlead in different positions of the automatic opening mechanism of Figure 4;

6 shows in greater detail the automatic opening mechanism of Figure 4;

Figures 7, 8, 9 and 9a represent sectional automatic opening mechanism of Figure 4;

The Figure 10 shows the variation in force on a tab of Figure 4 the mechanism depending on the stroke of the tongue;

11 shows a kinematic diagram of the first embodiment;

Figure 12 shows in perspective a second embodiment of an automatic opening mechanism of the fairlead;

FIG 13 is a side view of the automatic opening mechanism of the second embodiment.

For clarity, the same elements bear the same references in the various figures.

The invention is described in relation to the towing a sonar by a surface vessel. It is understood that the invention can be implemented for other items towed.

1 shows a vessel 10 towing a sonar 11 comprising an active acoustic transmitting antenna 12 often called fish and an acoustic receiving antenna 13 often called flute. The sonar 11 also includes a cable 14 to tow the two antennas 12 and 13. The cable 14 also provides the routing of signals and power between the vessel 10 and the antennas 12 and 13 of the sonar 11.

The antennas 12 and 13 are mechanically secured and connected electrically and / or optically to the cable 14 appropriately. Conventionally, the receiving antenna 13 is formed

a linear array of identical tabular form to those found in passive sonars, hence its name flute, while the transmitting antenna 12 is integrated in a volume structure having a shape resembling that of a fish. Receiving flute is generally disposed at the rear, at the end of the cable 14, the fish being positioned on the part of the nearest cable 14 of vessel 10. During an acoustic undersea mission, the the antenna 12 emits sound waves in the water and the receiving antenna 13 captures possible echoes from targets on which reflect sound waves from the antenna 12.

The receiving antenna 13 is generally secured permanently to the cable 14 so that the fish 12 is, in turn, secured in a removable manner. For this purpose the cable 14 includes a securing area 15 of the fish 12, zone in which are located means for mechanically securing the fish 12 and to realize the electrical connection and / or optical cable 14.

Setting to ' water and the outlet water of the antennas 12 and 13 is performed by means of a winch 16 arranged on a ship's deck 17, 10. The winch 16 comprises a drum 18 sized to permit the roll cable 14 and the receiving antenna 13. the winch 16 also comprises a frame. The reel 18 rotates relative to the frame to allow the winding of the cable. The winding of the cable 14 makes it possible to haul fish 12 on the ship 10, for example on a rear platform 19 provided for this purpose.

A fairlead 20 permits the guide 14 downstream of the cable drum 18. The fairlead 20 is the last guide element of the cable 14 before being lowered into the water. During towing, the inclination of the cable 14 can vary with respect to the longitudinal axis of vessel 10. The variations in inclination are mainly due to changes of cap and vessel speed and also to the state of the sea. one of the functions of the fairlead 20 is to ensure the cable 14 and the linear antenna that their respective radii of curvature do not exceed a predetermined lower limit. The cable 14 comprises for example a core formed of electric conductors and / or optical for transmitting energy and information between the sonar equipment located on board the ship 10 and the antennas 12 and 13. The cable core 14 is usually covered with a metal strand son of ensuring the mechanical strength of the cable 14 including tensile strength. Below the lower limit of curvature, permanent deformations or components of the cable breaks one risks 14. It is the same for the linear antenna.

In Figure 2, there is shown in more detail in side view

(Since starboard) the towing device elements. The fairlead 20 comprises a frame 21 designed to be fixed on a bridge 19 of the ship, sea side with respect to the winch 16. The bridge 19 is here an aft deck of the vessel 10. In other words, the fairlead 20 is secured to the back of the ship 10 relative to the winch 16. in the embodiment of the figures, the fairlead 20 and the winch is not fixed on the same bridge but could alternatively be arranged on the same deck. A spooling device 22 to properly store cable you 14 on the drum 18 is interposed between you hoist 16 and the fairlead 20. The cable 14 is here guided by the spooling device 22 between the fairlead 20 and winch 16. Alternatively the frame 21 is secured to a spooling 22. in other words,

Side sea, the cable 14 may fluctuate depending on the state of the sea, or simply when the ship shift. To this end, the fairlead 20 may include a number of sectors hinged together and each for guiding the cable 14. Such fairlead is by example described in patent application WO 2015/014886 A1 filed in the name of the Applicant. In this document, the axis of the articulation sectors intersects the main axis along which the cable extends. It is possible to arrange the axis of rotation of the joint sectors differently, such as described in W0 2013/068497 A1 also filed on behalf of the applicant. It is of course possible to implement the invention in a fairlead not understanding that

3 shows the fairlead 20 wherein transits fish 12. The fish 12 comprises two arms 12a and 12b to hang it on the cable 14.

The fairlead 20 comprises a first sector 23 fixed relative to the frame 21, and a second sector 24, called pivoting section, allowing both for guiding the cable 14. Each of the sectors 23, 24 comprises a channel or groove 25 for the sector 23, 26 to the area 24. the cable 14 slides in the channels 25 and 26 which are substantially in the extension of one another so as to guide the cable 14 along the fairlead 20. Each of the channels 25 and 26 allows a bending of the cable 14. the channels 25 and 26 are sized and arranged to limit the maximum curvature of the cable 14 at a predetermined curvature. The sectors 23 and 24 are hinged together. The sector 24 is pivotable about an axis 28 relative to the sector 23.

Sectors 23 and 24 have sections in the shape of the letter C to guide the cable in the lower part of the C and more specifically in the channels 25 and 26. The opening of the C allows to pass the arms 12a and 12b of the fish 12. to prevent cable outlet 14 of the fairlead 20 during sudden movements of the cable 14, the open side of the fairlead 20 comprising at least one closed section. According to the invention this closed section opens and closes automatically during the passage of the arms 12a and 12b.

Figure 4 shows in perspective a first embodiment of an automatic opening mechanism of the fairlead 20. The two channels 23 and 24 extend in a main direction 27 that follows the cable 14. In the example shown, the steering 27 is curved. Its curvature is defined to limit the cable 14. As part of the invention that direction can also be right. A section of the fairlead 20 is defined in a plane perpendicular to the direction 27.

The fairlead 20 comprising:

• 30 mobile bolt closing a section of the 24 sector

• a force sensor 32 located in front of the bolt 30 in a direction 34 carried by the main direction and configured to detect an external force, and • a shutter 36 configured to open the latch 30 when a force exerted on the first sensor 32 and oriented along the main axis in the direction 34 exceeds a predetermined force and to close the bolt 30 when this force disappears.

In Figure 4 the direction 34 corresponds to the raising of the fish 12 to the winch 16. The predetermined force corresponds to that exerted by the arms 12a and 12b when in contact with the force sensor 32. Advantageously, the force sensor 32 may also detect a force in the opposite direction to the direction 34 and thee shutter opens the bolt 30 also when the force detected by the force sensor 32 in the reverse direction exceeds the predetermined force and closes the bolt 30 when this force disappears. Thus the bolt 30 opens and closes when the fish 12 and specifically each of the arms of the fish 12, 20 through the fairlead both during his ascent towards the winch 16 that during its descent into the water.

When you fairlead includes a plurality of sectors 23 and 24, as in the example shown, advantageously associated with each sector, the fairlead 20 may include its own automatic opening mechanism. The automatic opening mechanisms of each of the sectors 23 and 24 can operate simultaneously. The outbreak of the opening is then made using a common force sensor to different mechanisms. Alternatively, the various operating mechanisms independently from each other, each having its own force sensor. This independence allows to minimize the time to open the various bolts to secure the best cable you 14 inside the fairlead 20.

Figures 5a, 5b and 5c show the fairlead 20 profile in different positions of the automatic opening mechanisms associated with each sector 23 and 24. In these figures can be seen the latch 30 and the force sensor 32 of the sector 24 as well as a bolt 40 and a force sensor 42 associated with the sector 23. in Figure 5a, the bolts 30 and 40 are closed, in Figure 5b the bolts 30 and 40 are open so as to let the fish 12 to F sea ​​and in Figure 5c the bolts 30 and 40 are open so as to let the fish 12 to the winch 16. in the variant shown, your bolts are movable in rotation about an axis 31 for the latch 30 and around an axis 41 for the bolt 40.

6 shows in more detail the area 24 and its opening mechanism. The force 32 includes a tongue 33 movable sensor in rotation about the axis of rotation 31. The force sensor 32 can detect a forward force of the bolt 30 in the direction of movement being considered for the cable 14. In other said, when one 12a or 12b approach the automatic door opener arm, a contact takes place with the tab 33 which is located forward of the bolt 30. Thus no contact occurs with the bolt 30 itself. Indeed, such contact may affect its opening and lead to damage of the bolt 30 and the arm 12a or 12b. In Figure 6 we distinguish advance of the tab 33 in the two directions of possible movement of the cable 14. The advance is for example angular of ten degrees: 45 advance when the fish 12 through the fairlead 20 advance towards the sea and when the fish 46 12 20 through the fairlead to winch 16. den forms tabs 33 are also possible and can be advance linearly set. The automatic opening mechanism of the sector 23 is constructed similarly to the sector of the mechanism 24 with advances in both directions of movement of the cable 14 in the fairlead 20.

7 shows the mechanism of ' automatic opening section through the axis 31.

The shutter 36 is located inside of a bell 50 integral with the tab 33. The trigger 36 principally comprises a pawl 52 that can take three positions: a position where the latch 30 is closed as shown in Figure 5a and two positions open when the latch 30 is open as shown in Figure 5b and 5c. The closed position is effective without effort on the tongue 33 and the open positions are reached when a force greater than a predetermined force in either direction driven by the ' main axis 27 is exerted on the tongue 33. The pawl 52 can not have only one open position if a pressure force on the tongue 33 is detected only in one direction.

The pawl 52 is also visible on the HH and DD sections shown in Figures 8 and 9. The DD HH and cutting planes are perpendicular to the axis 31 and their position is identified in Figure 7.

The automatic opening mechanism has a shaft 54 extending along the axis 31. The ' shaft is attached to the bolt 30 not shown in Figure 7. One end 56 of the shaft 54 may be splined to ensure the in position of the mechanism with the bolt 30. the position keeps the mechanism and the bolt 30 can be ensured by means of a thread 58. any other means for positioning and holding in position is of course possible. The mechanism includes a frame 60 secured to the sector 24. The bolt 30 and the tongue 33 are rotatable around ' axis 31 relative to frame 60 and therefore with respect to sector 24.

The pawl 52 includes two fingers 61 and 62 rotatable relative to the frame 60 about an axis 64. The fingers each have a hook 65 for the finger 61 and 66 to the finger 62. When the pawl 52 is in position closed as shown in Figure 8, the hooks 65 and 66 abut against the shaft 54. thus, the bolt 30 is locked relative to the frame 60 and can not therefore move relative to the sector 24. the pawl 52 comprises a spring 68 keeping the two fingers 61 and 62 abut on the shaft 54. the hooks 65 and 66 may abut directly against the shaft 54 ​​or advantageously against a cam 67 connected to the shaft by screws 69 forming mechanical fuses. In normal operation the cam 67 and shaft 54 ​​are integral with one another.' Force on the force sensor exceeds the predetermined threshold for opening.

During one of the tongue rotational movement 33, a pin 70, integral with the tongue 33, opens the pawl 52 away from one of the fingers 61 and 62. In practice, the pin 70 is fixed to the bell 50 which itself is fixed to the tongue 33.

Moreover, a first spring 72 opposes the rotation of the tab 33 relative to the bolt 30 which in the closed position of the pawl 52 is fixed. Moreover, in addition to the spring 72, the inner shape of the fingers 61 and 62 on which bears the pin 70 and the shape of the hooks 65 and 66 are configured to define the force beyond which the pawl 52 s te ' opens to release the bolt 30. Figure 9a is an enlarged portion of Figure 9 where we distinguish the shape of the fingers 61 and 62 in the vicinity of the equilibrium point where no force is exerted on the tongue 33. when a support appears on the tongue 33, the pin 70 moves by pushing e.g. finger 62. Running top finger inner shape is substantially flat to avoid inducing any movement of the finger 62. This flat area is marked 76. Then, by continuing its stroke, the pin 70 reaches an inclined shoulder 78 causing the finger 62 to move away from the shaft 54. The hook 66 is released from its abutment. It is during the transition from this shoulder that the bolt 30 is released. Still continuing its stroke the pin 70 reaches a substantially circular area 80 about the shaft 54. In this area the hook 66 is kept away from its stop. The inner shapes of the other finger 61 are for example symmetrical. Asymmetrical shapes are possible, in particular to shift the advance in one direction relative to the other or for different forces to be applied by one of the fish 12 or 12a arm 12b in one direction and in the other. A stress difference can be useful because the descent to the sea, only drag the flute 13 drives the fish while during the ascent of the fish, the winch 16 can exert more effort. Moreover, save for the rise, fish 12, the fairlead 20 and thus the tongue 33 are likely to receive seas. Therefore, it is useful to differentiate the predetermined force values ​​to be exerted on the tongue 33 you open latch 30 to lift fish 12, corresponding to the direction 34 and the descent of the fish corresponding to the opposite direction. The predetermined force value in the direction 34 is thus preferably greater than the predetermined force value in the opposite direction. fish 12, the fairlead 20 and thus the tongue 33 are likely to receive seas. Therefore, it is useful to differentiate the values ​​predetermined force to be exerted on the tongue 33 to open 30 to you bolt the rise of fish 12, corresponding to the direction 34 and the descent of the fish corresponding to the opposite direction. The predetermined force value in the direction 34 is thus preferably greater than the predetermined force value in the opposite direction. fish 12, the fairlead 20 and thus the tongue 33 are likely to receive seas. Therefore, it is useful to differentiate the values ​​predetermined force to be exerted on the tongue 33 to open 30 to you bolt the rise of fish 12, corresponding to the direction 34 and the descent of the fish corresponding to the opposite direction. The predetermined force value in the direction 34 is thus preferably greater than the predetermined force value in the opposite direction. corresponding to the direction 34 and the descent of the fish corresponding to the opposite direction. The predetermined force value in the direction 34 is thus preferably greater than the predetermined force value in the opposite direction. corresponding to the direction 34 and the descent of the fish corresponding to the opposite direction. The predetermined force value in the direction 34 is thus preferably greater than the predetermined force value in the opposite direction.

It is also possible to differentiate the effort to open the latch 52 in both directions of rotation by doubling the spring 72, one acting in one direction and the other acting in the other direction. For each of the two springs, it is possible to choose different stiffness and different prestressed.

Once the pawl 52 open, forms no longer block the rotation of the bolt 30. The spring 72 then applies a return action of the

bolt 30 to realign the bolt thee 30 with the tongue 33 and thus to avoid contact between the arm 12a or 12b and the bolt 30.

Advantageously, the mechanism includes a second spring 74 connected between the frame 60 and the first spring 72 and tending to close the bolt 30 which is secured to the common point between the two springs 72 and 74. By choosing a stiffness of the second spring 74 below that of the first spring 72, it is possible both to limit the effort needed to complete opening of the mechanism and both retain an important trigger effort of the catch 52 and thus maintain the minimum effort to overcome trigger the opening of the bolt 30.Arranging the two springs 72 and 74 in series between the 60 housing and the tongue 33 with the bolt 30 attached to the common point of the two springs 72 and 74 maintains an angular offset between the tongue 33 and the bolt 30 and thus avoid contact between the arm 12a or 12b and the bolt 30.

The two springs 72 and 74 are preloaded so as allow you return to the closed position when pressing the tab 33 ceases. It is possible to adjust the preload and the stiffness of the spring 74 to a value smaller than the spring 72 to further reduce the effort necessary to achieve the open position of the bolt 30.

Alternatively, it is possible to use a single spring applying both a point of the bolt 30 relative to frame 60 and a point of the tongue 33 relative to the frame 60. Nevertheless, the implementation of a {Seui spring direction) has the disadvantage of leaving the free tab 30 during opening of the pawl 52 and that is an arm of the fish that grows on the bolt 30 after the unlocking pawl 52. in addition, this variant for the same predetermined force for triggering the opening of the bolt 30 causes a force needed to fully open as shown in Figure 5b or 5c greater than the tripping force in the embodiment with two springs (direction) and a congestion largest spring to accept the magnitude of opening.

The spring 74 is preloaded between two flanges 82 and 84 free rotation relative to the frame 60 each in an angular sector giving possible angular travel for the bolt 30 for one direction of rotation. The

position of equilibrium is shown in Figure 9 where the flange 82 abuts against a ctavette 86 fixed to the frame 60. The flange 82 comprises a free angular sector 88 allowing it to rotate relative to the frame 60 twisted rotation of the bolt 30 in one direction of rotation. In the example shown, the maximum rotation of the bolt 30 is 110 * . A maximum rotation amount of the order of 90 ° or slightly greater allows the bolt 30 to be retracted sufficiently when fish arm passage 12. The flange 84 comprises a similar angular sector permitting rotation of the bolt 30 in the other direction of rotation. The free angular sectors of the flanges 82 and 84 may be different according to the maximum desired shopping for bolt 30 in both directions of rotation.

As for the spring 72, it is possible to split the spring 74 to distinguish both stiffness that the preloading in both directions of movement of the cable 14 in the fairlead 20.

10 shows in curve form the force applied to the tab 33 according to the movement thereof in one direction driven by the main direction 27. In practice, the springs 72 and 74 are, in the variant shown, the torsion springs, the force is given as a torque rated C. in addition, the tongue 33 moving in rotation, its displacement is expressed as angle noted. A functional clearance a1 e.g. about 1 ° is provided between the cam 67 and the pawl 52, specifically, between the fingers 65 and 66 and the cam 67. This play ensures the return of the pawl 52 in the closed position and thus the latch 30 in the closed position. C1 represents a torque preload spring 74. At the beginning of movement of the tongue 33 of a support in either direction driven by the main direction 27, the a1 functional clearance is caught by a tension spring 74. Once caught this game, the pawl 52 bears on the cam 67 and the torque required for rotation of the tab 33 is the preload torque C2 of the spring 72 which is greater than the torque C1, where the vertical portion of the curve between C1 and C2 couples to the angular position a1 . Beyond the position a1, the pin 70 traverses the flat area 76 and the spring 72 is stretched from a C2 preload until a position a2 for example of the order of 2.5 °. At this position the pin 70 comes into contact with the shoulder 78. The slope of the curve between the positions CT1 and Q2 is given essentially by the stiffness of the spring 72. Then the pin 70 moves on the shoulder 78 and the curve becomes substantially vertical to achieve C5 triggering of the predetermined force to be exceeded for free rotation of the latch 30 and thus allow its opening. The C5 effort is achieved for example by an angular position Q3 of 3 ° which is less than the advance of the tab 33 relative to the bolt 30. This advance is shown in Figure 10 by an angular position a4, for example, the about 10 °. Thus the bolt 30 opens before the object (ie fish) that triggered the opening reaches it. shoulder 78 and the curve becomes substantially vertical to achieve the predetermined force C5 exceed trigger to release the rotation of the bolt 30 and thus allow its opening. The C5 effort is achieved for example by an angular position Q3 of 3 ° which is less than the advance of the tab 33 relative to the bolt 30. This advance is shown in Figure 10 by an angular position a4, for example, the about 10 °. Thus the bolt 30 opens before the object (ie fish) that triggered the opening reaches it. shoulder 78 and the curve becomes substantially vertical to achieve the predetermined force C5 exceed trigger to release the rotation of the bolt 30 and thus allow its opening. The C5 effort is achieved for example by an angular position Q3 of 3 ° which is less than the advance of the tab 33 relative to the bolt 30. This advance is shown in Figure 10 by an angular position a4, for example, the about 10 °. Thus the bolt 30 opens before the object (ie fish) that triggered the opening reaches it. advance of the tongue 33 relative to the bolt 30. This advance is shown in Figure 10 by an angular position a4 for example of the order of 10 °. Thus the bolt 30 opens before the object (ie fish) that triggered the opening reaches it. advance of the tongue 33 relative to the bolt 30. This advance is shown in Figure 10 by an angular position a4 for example of the order of 10 °. Thus the bolt 30 opens before the object (ie fish) that triggered the opening reaches it.

Between the equilibrium position where a = 0 ° and the position a3, the tongue 33 moves angularly without the bolt 30 from rotating. At the release of the bolt 30, it realigns with the tab 33. In other words, beyond the position a3, the tongue 33 found it had advance on the bolt 30 to the rest position for a = 0 ° in order to avoid contact between the arm 12a or 12b with the bolt 30. the stiffness of spring 72 participates in the realignment of the bolt 30 with the tab 33.

After opening of the bolt 30, the curve of Figure 10 returns to a lower value and follows a moderate slope given by the stiffness of the second spring 74. The descent of the curve is due to the transition between regions 78 and 80 of the finger 62 as well as the release of the hook 66 which rub against its stop on the shaft 54. the C1 prestress of the second spring 74 is, in the example shown, smaller than the C2 prestressing of the first spring 72. Alternatively, it is possible not to preload the first spring 72 provided that its stiffness is sufficiently high for its return torque exceeds the torque C1 preload of the second spring 74 to the angular position a2.

Beyond the position a3, the rotation of the tongue 33 continues until the position a5, for example, about 1 10 °, to the position of any point torque is C3 essentially a function of the stiffness of second spring 74.

The alternative to a single spring (direction) is also shown in dotted lines in Figure 10. from a C4 preload, the single spring is stretched until a C6 torque to the A5 position. C6 torque arises from the stiffness of the single spring and the minimum torque C5 desired for the torque to opening of the mechanism to position your a3. The alternative to a single spring causes a much larger value as the value C6 C3 if the spring rate is important. You can choose for this unique spring lower stiffness (slope less pronounced fa dotted curve) but ceta requires a very significant increase in bulk.

The curve is substantially symmetrical about the y-axis near the adjustments described above, the maximum torque value C5 and angular amplitude which can be adjusted differently in the two directions of rotation. Thus the bolt 30 tends to return to its equilibrium position closed whatever its direction of rotation.

Returning to the embodiment with two springs 72 and 74 when the force on the tongue 33 disappears, the tongue 33 and the latch 30 are closed along a curve directly from the point of the curve (a5, C3) at (0 , Cl) and (0,0). C1 preload of the second spring 74 ensures the closing of the bolt 30 and the return of the pin 70 to its equilibrium position.

The return of the tongue 33 relative to the shaft 54 ​​takes place in similar manner to that of the bolt 30 relative to the frame 80. The spring 72 is preloaded between two flanges 90 and 92 movable in rotation relative to the shaft 54. the flange 90 is coupled to the shaft 54 ​​via a key and the flange 92 is coupled to the bell 50 and therefore to the tongue 33 via a pin. The angular displacement of the flange 90 is about 10 ° with respect to the shaft 54, it corresponds to advance 45 and 46 of the tongue 33 relative to the bolt 30, it can be ensured as before by means of a key fixed to the shaft 54 ​​and a free angular sector réatisé in the flange 90.

11 shows a kinematic diagram of the first embodiment. In this diagram a few variations have been shown with respect to the cross-sectional representations of Figures 7 to 9. Specifically, in Figures 7 and 8, there are a spring 68 tending to return the two fingers 61 and 62 bearing against the shaft 54 through brackets 65 and 66. on the kinematic diagram of Figure 11, the spring 68 has been replaced by two springs 68.1 and 68.2. 68.1 the spring is disposed between the finger 61 and the frame 60. The 68.1 spring tends to return the finger 61 bears against the shaft 54. Similarly, the spring 68.2 is disposed between the finger 62 and frame 60. The spring you 68.2 tends to return the finger 62 bears against the shaft 54. This doubling of the spring 68 allows to differentiate the effort to

The pin 70 integral with the bell 50 and the tongue 33 appears in the diagram of Figure 11. The contact pin 70 that you can have on one of the fingers 61 or 62 is shown as a straight linear link. A one-off connection is also possible. It is understood that the pin 70 carries only one contact at a time, either on the finger 61 or the finger 82. Accordingly, only one of rectignes linear connections is effective at the time the the other being absent.

The kinematic diagram of Figure 11, the springs 72 and 74 have also been resolved as discussed above. For one of the directions the function provided by the spring 72 is provided by the 72.1 spring held between two flanges 90.1 and 92.1. In the other direction, the function provided by the spring 72 is ensured by spring you 72.2 maintained between 90.2 and 92.2 flanges.

Similarly, to one direction the function provided by the spring 74 is provided by the 74.1 spring held between two flanges 82.1 and 84.1. For the other direction, the function provided by the spring 74 is provided by spring 74.2 you held between the two flanges 82.2 and 84.2. The pin 86 integral with the frame 60 is also split and shown in Figure 11. The flange 82.1 86.1 abuts against the key. 82.2 the flange abuts against the key 86.2. These supports are shown schematically as straight linear bonds that can be lost when corresponding flange rotates relative to the shaft 54, for example in the free angular sector 88 to the flange 82 as shown in Figure 9.

12 shows in perspective a second embodiment of an automatic opening mechanism of the fairlead 20. There are the two areas 23 and 24. It is understood that this second embodiment can be implemented in a fairlead in one sector.

Found in the second embodiment, the tongue 33 for detecting an effort. Include a bolt 100 that, unlike the first embodiment opens and closes according to a translatory movement along an axis 102. The bolt is guided in translation with respect to the sector 24 along the axis 102.

FIG 13 is a side view of the automatic opening mechanism of the second embodiment. The tongue 33 is, as before, mobile in rotation about the axis 31 relative to the area 24. As before, the force sensor 32 can detect a forward force of the bolt 30 in the direction of movement being considered for the cable 14. This advance is clearly visible in Figure 12 where the tongue 33 protrudes from the bolt 100 in at least one direction carried by the main direction 27 followed by the cable 14 in the area 24. in the example shown, the tab 33 protrudes from the bolt 100 in either direction. The outer form of the tongue 33 on which the arms of the 12 fish are intended to support sets the advance of the bolt 100.

A pinion 104 is secured to the tongue 33. The gear 104 rotates about the axis 31. A second pinion 106 is rotatable relative to the area 24. The axis of rotation 108 of the pinion 106 is distinct from the axis of rotation 31 of the pinion 104. the pinion 106 is driven by the gear 104 via a belt 10. the tongue 1 33, the pinions 104 and 106 and the belt perform the function of the force sensor 32.

A cam 1 12 is integral with the pinion 106. An arm 1 14 may be pivoted at one of its ends 116 with respect to sector 24 about an axis 18 January distinct rotational axes 31 and 108 of both sprockets 104 and 106. The one arm 14 includes a roller 120 forming a cam follower and pressing the cam 1 12. the bolt 100 includes a pin 122 slidable in a groove 124 formed in the arm 114 at its second end 126. the cam 1 12 , the arm 114 and the roller 120 perform the function of the shutter 36.

The arm 1 14 forms a lever to translate the bolt 100 about its axis 102. The shape of the cam 1 12 is defined to coordinate the translational movement of the bolt 100 as a function of angular displacement of the tongue 33. The ratio of distance between on the one hand the pin 122 and the axis of rotation 1 18 and on the other hand the roller 120 and the axis of rotation 1 18 makes it possible to amplify the displacement of the bolt 100 relative to the rotation of the tab 33. This amplification can be changed by the ratio of the diameters of the pinions 104 and 106. in the example shown, the sprockets 104 and 106 so that the arm 1 14 amplifies the displacement in translation of the bolt 100. A reduction is also possible.

Any other means for transforming the rotational movement of the tongue 33 into a translational movement of the bolt 100 is possible within the framework of the invention, such a crank type system.

To prevent the 120 leaves its contact with the cam roller 112, the latter advantageously comprises a groove 130 in which the roller moves 120. The roller 120 then remains in contact with the two flanks of the groove 130.

The cam profile 112 on which the roller rests 120 is preferably defined so that the mechanism is irreversible, ie a force on the bolt 100 can not open it. This will prevent the cable rubbing on the bolt 100 can turn it up. Thus only a force on the tongue 33 tending to rotate around its axis 31 to open the latch 100.

The profile of the cam 112 is symmetrical with respect to balance point shown in Figure 13. This equilibrium corresponds to the low position of the bolt 100 where it closes the sector 24. The symmetrical shape of the cam 112 allows identical movements of the bolt 100 according to the rotation of the tab 33 back and forth carried by the direction 27. It is possible to provide different shapes for each of the two directions depending on the desired movement to the bolt 100.

The mechanism includes a return spring 132 tending to keep the latch 100 in the closed position. A spring preload 132 sets the minimum force to be exerted on the tab 33 to open the latch 100. The spring 132 can be attached directly between the sector 24 and the bolt 100. This provision of the spring 132 only works if the mechanism is reversible. In the case of an irreversible mechanism, the spring 132 may be directly fixed between the sector 24 and the cam 112 so as to exert a torque on the cam 112, this torque tending to hold the roller 120 to the position 'balanced. In the example shown, in order to accentuate the effect of spring 132, the mechanism includes a ring 134 rotatably with respect to the sector 24 and a pinion 136 secured to the cam 112. The crown 134 and the pinion 136 rolling without slide one over the other. For this purpose, the ring 134 and the pinion 136 include, for example cooperating gear teeth. Relative to the plane of Figure 13, the pinion 136 is located behind the cam 112, while the gear 106 is located in front of the cam 112. The spring 132 is set between the sector 24 and the ring 134. The diameter ratio between the pinion 136 and the crown 134 amplifies the return force of the spring 132.

CLAIMS

1. fairlead intended to equip a towing device which can be installed on the deck of a ship (10) and comprising a winch (16), a cable (14) flowing through the fairlead (20) under the action of the winch ( 16), the fairlead (20) comprising a channel (24) with an open section extending in a main direction (27) for guiding the cable (14), characterized in that the fairlead (20) further comprises:

• a bolt (30, 40, 100) closing a movable section of the channel (24),

• a force sensor (32) located in front of the bolt (30, 40, 100) in a direction (34) carried by the main direction (27) and configured to detect an external force, and

• a shutter (36) configured to open the latch (30, 40, 100) when a force exerted on the sensor (32) and oriented along the main axis (27) in direction (34) exceeds a predetermined load and to close the bolt (30, 40, 100) when this force disappears.

2. fairlead according to claim 1, characterized in that the force sensor (32) is configured to detect an external force in front of the bolt (30, 40, 100) back and forth carried by the main direction (27) and the shutter (36) is configured to open the bolt (30. 40, 100) when a force exerted on the sensor (32) and oriented along the main axis (27) in both directions beyond the predetermined force and to close the bolt (30, 40, 100) when this force disappears.

3. warping according to one of the preceding claims, characterized in that the bolt (30, 40) is rotatable relative to the channel (24) about an axis of rotation (31) substantially perpendicular to the main direction ( 27).

4. warping according to claim 3, characterized in that the force sensor (32) comprises a tongue (33) rotatable about the axis of rotation (31), in that the shutter (36) comprises a pawl (52) which can assume two positions, a first position, called the closed, is effective without effort on the tongue (33) and maintains the bolt (30. 40) closed and a second position, said open, allows free rotation the bolt (30, 40), in that the pawl (52) is driven by the tongue (33) from the closed position to the open position after passing the predetermined force, the fairlead further comprising a first spring (72 ) connected between the first channel (24) and the tongue (33), the stiffness of the spring (72) participating in the predetermined force, and the realignment of the bolt (30) with the tongue (33).

5. warping according to claim 4, characterized in that the first spring (72) is pretensioned, the pretensioning participating in the predetermined force, and the realignment of the bolt (30) with the tongue (33).

6. warping according to one of Claims 4 or 5, characterized in that the shutter (36) comprises a second spring (74) tending to close the latch (30, 40), the second spring (74) being connected in series with the first spring (72), in that the bolt (30) is integral with the common point between the two springs (72, 74).

7. warping according to claim 6, characterized in that the second spring (74) has a lower stiffness than the first spring (72).

8. warping according to one of Claims 6 or 7, characterized in that the second spring (74) is biased to a value smaller than the first spring (72).

9. warping according to one of claims 1 or 2, characterized in that the bolt (100) is movable in translation relative to the channel along an axis (102) substantially perpendicular to the main direction (27).

10. warping according to claim 9, characterized in that the force sensor (32) comprises a tongue (33) rotatable about an axis of rotation (31) substantially perpendicular to the main direction (27) and means for transforming a rotational movement ia tongue (33) in translation with the bolt (100).

11. warping according to claim 10, characterized in that your means for transforming a rotational movement the tongue (33) in translation with the bolt (100) are irreversible.

12. warping according to one of claims 10 or 11, characterized in that it comprises a cam (112) rotating with the tongue (33) and a lever (114) pivotally comprising, at a distance from its pivot axis (118 ), a pin (120) supported on the cam (112) and a groove (124) in which the bolt rests (100).

13. warping according to claim 12, characterized in that it comprises a spring (132) for biasing tending to return the cam (112) to an equilibrium position in which the bolt (100) is closed.

14. A towing device can be installed on the deck of a ship (10) and comprising a winch (16), a cable (14) and a fairlead (20) according to one of the preceding claims, the fairlead (20) and the winch (16) being fixed relative to each other.