Chain weighting device

Abstract

The present invention relates to a device for ballasting a chain 12, in particular in an underwater environment, said device comprising at least: a single-piece ballasting element 10, said ballasting element 10 being crossed by a hole 101 formed along a longitudinal axis X of said ballasting element 10 and allowing the passage of said chain 12; means for securing said chain 12 to said ballasting element 10. According to the invention, said securing means comprise: a drawer 13 comprising two half-drawers 131 capable of being assembled to delimit an internal housing 1310 shaped to house a link 120 of said chain 12; at least one securing key 11 of said drawer 13 to said ballasting element 10 without interaction with said chain 12. Fig. 1

Description

Title of the invention: Device for weighting a chain 1. Field of the invention

[0001] The field of the invention is that of devices and methods for ballasting chains used as offshore anchor lines, for example: - floating production units, or Floating Production Storage and Offloading (FPSO), in English; - any type of float, such as floating wind turbines; - electrical substations; - mooring buoy; 2. Prior art

[0002] Chains are commonly used to maintain the position of elements in offshore situations.

[0003] For this purpose, the chains are immersed, particularly in an underwater or more generally subaquatic environment, and ballasted locally in order to improve the dynamic response and the line lengths. To do this, several ballast devices are generally installed along a chain.

[0004] Two types of chain weighting device are known, namely: - devices comprising single-piece ballast elements; - ballast devices comprising two-part ballast elements assembled by bolting.

[0005] One-piece ballast elements comprise a one-piece mass, generally made of cast iron, with a hole passing through it for a chain to pass through. The ballast element is held securely attached to the chain, or more precisely to a link thereof, by means of an axle passing through the link of the chain and the ballast element.

[0006] The implementation of several ballast elements distributed along a chain makes it possible to achieve effective ballast of the chain on a seabed. However, in use, the ballast elements tend to act, via the axis, by constraining the crossed link, but also on the two adjacent links, which find themselves trapped between the axis and the link crossed by the axis.

[0007] This is likely to: - increase the transmission of forces with and without sliding between the links and the creation, on the links of the chain, of out-of-plane bending (OPB in English for “Out of Plane Bending”) and in-plane bending (IPB in English for “In Plane Bending”). - increase abrasion between the affected links.

[0008] This results in a significant risk of premature damage to the chain.

[0009] The two-part ballast elements comprise two half-ballast elements capable of being assembled to delimit a housing shaped to house a link of a chain. The assembly of the two half-ballast elements is carried out by means of bolts.

[0010] The implementation of such two-part ballast elements is simple insofar as they are easier to install and secure to a chain, and effective insofar as it allows suitable ballast to be achieved on a chain.

[0011] However, the main disadvantage inherent in two-part ballast elements is the risk of breakage of the bolts used to assemble them, which could result, if it occurs, in a dissociation of the two half-ballast elements and a loss of the ballast element fixed to the chain. The chain is then no longer ballasted or poorly ballasted, which is damaging.

[0012] There is therefore a need to improve chain ballasting devices. 3. Objectives of the invention

[0013] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0014] In particular, according to at least one embodiment, an objective of the invention is to improve chain ballasting devices.

[0015] In particular, the invention aims, according to at least one embodiment, to provide such a ballasting device which limits the risk of losing a ballasting element secured to a chain.

[0016] Another objective of the invention is, according to at least one embodiment, to provide such a ballasting device which is robust.

[0017] Another objective of the invention is, according to at least one embodiment, to provide such a weighting device which contributes to reducing the wear of a weighted chain therewith.

[0018] Another objective of the invention is, according to at least one embodiment, to provide such a ballasting device which is simple and / or economical. 4. Presentation of the invention

[0019] For this, the invention proposes a device for ballasting a chain, in particular in an underwater environment, said device comprising at least: - a single-piece ballast element, said ballast element being crossed by a hole formed along a longitudinal axis X of said ballast element and allowing the passage of said chain; - means for securing said chain to said ballast element.

[0020] According to the invention, said securing means comprise: - a drawer comprising two half-drawers capable of being assembled to delimit an interior housing shaped to house a link of said chain; - at least one key for securing said drawer to said weighting element without interaction with said chain.

[0021] Thus, the invention is based on the implementation of a single-piece weighting element capable of housing a drawer inside which a link of a chain can be placed.

[0022] This implementation makes it possible to provide a ballast device whose ballast element(s) are robust so that there is no risk of this or these ballast elements becoming detached from a chain as is the case with two-part ballast elements.

[0023] It also makes it easier to secure the ballast device to the chain due to the use of a two-part drawer.

[0024] The invention avoids the use of an axis passing through a link of the chain to secure it to the weighting element and the drawbacks inherent in this prior art technique.

[0025] This implementation further makes it possible to reduce the forces on the links of a weighted chain and thus to avoid premature wear of a weighted chain compared to an unweighted chain.

[0026] The invention therefore makes it possible to combine the advantages of the two techniques of the prior art without presenting their defects.

[0027] According to a possible characteristic, a ballasting device according to the invention comprises means for taking up play between said keys, said drawer. This implementation makes it possible to avoid the occurrence of play between the drawer and the ballasting element.

[0028] It is also preferable to provide clearance between the ballast element and a chain link housed inside to limit the transmission of force between the ballast element and the link and thus preserve the latter.

[0029] According to a possible characteristic, said hole of said ballast element has a frustoconical internal peripheral contour along said longitudinal axis, said drawer having a frustoconical external contour of a shape complementary to said peripheral contour of said hole, said drawer thus being capable of being assembled to said ballast element at least in part by a conical assembly. This makes it possible to ensure an assembly of the drawer and the ballast element which is at least partly conical. This makes it possible to limit, or even eliminate, the shear in the securing keys in the main direction of stress, the ballast element then taking up the stress induced by the drawer when the chain link acts on the drawer.

[0030] According to a possible characteristic, at least one locking housing is provided in said ballast element orthogonally to said longitudinal axis, said at least one locking housing making it possible to receive said at least one key.

[0031] This allows for simple and effective connection of the drawer and the ballast element by means of keys.

[0032] According to a possible characteristic, at least one notch is provided on the periphery of said drawer orthogonally to said longitudinal axis, said at least one notch allowing the passage of said at least one key.

[0033] This allows for simple and effective connection of the drawer and the ballast element by means of keys.

[0034] According to a possible characteristic, said at least one key has an essentially quadrangular section.

[0035] According to a possible characteristic, said at least one key has a beveled side located opposite a non-beveled side, the inclination of said beveled side of said at least one key being configured to act against said weighting element and said non-beveled side being configured to act against one of said notches of said drawer housing said at least one key, during an introduction of said at least one key into said at least one locking housing and move a small diameter end of said drawer towards a small diameter end of said hole.

[0036] This implementation makes it possible to produce play-compensating means so as to fill the play between the drawer and the ballast element and thus prevent them from moving relative to each other when they are assembled.

[0037] According to a possible characteristic, said at least one locking housing has an open end for insertion and extraction of said at least one key, said beveled side of said at least one key being arranged on the side of said large diameter ends of said drawer and of said hole, the section of said at least one key tending to decrease in the direction of one end of said at least one locking housing opposite their open end.

[0038] This implementation makes it possible to simply but effectively compensate for the play between the drawer and the ballast element.

[0039] According to a possible characteristic, said securing means comprise at least one plate for closing said at least one open end to hold said at least one key in said at least one locking housing.

[0040] This makes it possible to ensure effective connection of the keys to the ballast element in a simple and safe manner.

[0041] According to a possible characteristic, said securing means comprise at least one locking insert of said at least one key, said at least one locking insert being placed in a locking cavity of said element of ballast, each locking cavity having a lateral opening for introducing said insert along an axis orthogonal to the axis of said at least one key and to the axis of said hole, and being delimited, along the axis of said at least one key, by a first bearing surface oriented towards said at least one locking housing and a second bearing surface opposite said first bearing surface, said at least one insert bearing against said second surface when a key is housed in said corresponding locking housing, said at least one locking insert having an internal lumen for the passage of said at least one key, one end of said at least one key projecting inside said lumen when it is housed in said locking housing.

[0042] This also makes it possible to ensure simple and safe effective connection of the keys to the ballast element.

[0043] According to a possible characteristic, said at least one insert comprises means for reversibly securing to said insert a cylinder body having a piston capable of acting on said at least one key along the axis of said at least one key to insert it and constrain it in said at least one corresponding locking housing.

[0044] It is thus possible to use a pressure cylinder pushing on each key towards the corresponding locking housing to finalize the positioning of the keys in their locking housing and finish taking up the play between the drawer and the hole in the ballast element by pressing on the insert, which presses on the ballast element.

[0045] According to a possible characteristic, said at least one closure plate is secured to said ballast element by screwing or welding and / or said at least one insert is secured to said at least one key by welding.

[0046] According to a possible characteristic, said at least one insert is crossed by a passage opening into said interior light in a region of said end of said at least one key forming a projection therein, said passage housing a weld bead for securing said at least one insert by plugging to said at least one key.

[0047] This ensures very effective and durable retention of the keys in their locking housing.

[0048] According to a possible characteristic, said at least one locking housing is blind.

[0049] According to another possible characteristic, said at least one locking housing is open-ended.

[0050] In this case, each key has a distal end which projects, outside said corresponding locking housing, beyond one end opening of said locking housing arranged opposite said open end, said device comprising means for locking said key, said locking means comprising at least one locking element secured to said distal end, said at least one locking element having at least one dimension greater than at least one dimension of said opening end.

[0051] This makes it possible, in the event that the locking inserts or the closure plates become detached from the ballast element, to guarantee that the keys remain inside the locking housings to hold the drawer in the hole, or even to replace the locking insert or closure plate function.

[0052] According to a possible characteristic, each key has a distal end which projects, outside said corresponding locking housing, beyond an emerging end of said locking housing arranged opposite said open end, said device comprising means for locking said key, said locking means comprising at least one locking element secured to said distal end, said at least one locking element having at least one dimension greater than at least one dimension of said emerging end.

[0053] According to a possible characteristic, a device according to the invention comprises means for self-centering the angularity of said drawer in said hole, said self-centering means comprising: - a guide element secured to said drawer, said guide element comprising two first opposite guide surfaces forming an angle relative to a plane passing through the axis of said hole and tightening towards each other in the direction of a small diameter end of said drawer; - a receptacle formed in said ballast element along the axis of said hole, said receptacle comprising two second opposite guide surfaces parallel to a plane passing through the axis of said hole of said ballast element, said receptacle being capable of housing said guide element.

[0054] This implementation makes it easier to insert the drawer into the hole in the ballast element and in particular its angular alignment with respect to the ballast element.

[0055] According to a possible characteristic, said at least one key extends outside said interior housing of said drawer so that it does not pass into said interior housing nor through a chain link, if any, housed therein.

[0056] Thus, when a chain link is housed in the weighting element, no axis passes inside it so that the neighboring links are not trapped between the link housed in the weighting element and the fixing axis. The neighboring links are thus preserved.

[0057] According to a possible characteristic, said inner housing of said drawer is shaped to retain said weighting element on said link housed in said inner housing of said drawer by contact on the outer peripheral contour of said link.

[0058] The recovery by external crown of the link trapped in the drawer makes it possible to block the translation of the link completely independently and without interaction with the adjacent link, unlike any system with recovery from the inside of the link, which would necessarily have a harmful effect on the adjacent link.

[0059] According to a possible characteristic, said drawer comprises at each of the ends of said internal housing a clearance shaped to allow free rotation of the links of said chain secured to said link housed in said internal housing.

[0060] This makes it possible to limit the forces transmitted between the neighboring links and the link housed in the ballast element, and thus to preserve these links.

[0061] The invention also covers a method for securing a ballast device to a chain according to any one of the variants set out above, said method comprising at least: - a step of passing said chain through at least one hole in at least one weighting element; - a step of positioning at least two half-drawers, forming at least one drawer, around at least one link of said chain so as to house said at least one link in at least one interior housing formed by said at least two half-drawers; - a step of inserting said at least one drawer into said at least one hole in said at least one weighting element, or vice versa; - a step of securing said at least one drawer to said at least one ballast element. 5. Description of figures

[0062] Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given as a simple illustrative and non-limiting example, and the appended drawings among which:

[0063] [Fig-1] [Fig.l] illustrates an exploded view of a ballasting device according to a first embodiment of the invention;

[0064] [Fig.2] [Fig.2] illustrates a perspective view of a weighting element of the device of ballast illustrated in [Fig.l];

[0065] [Fig.3] [Fig.3] illustrates a front view of the ballast element illustrated in [Fig.l];

[0066] [Fig.4] [Fig.4] illustrates a perspective view of a half-drawer of the device of ballast shown in [Fig.l];

[0067] [Fig.5] [Fig.5] illustrates a perspective view of the ballasting device illustrated in [Fig.l] attached to a link of a chain;

[0068] [Fig.6] [Fig.6] illustrates a side view of the ballasting device illustrated in [Fig.5] attached to a link in a chain;

[0069] [Fig.7] [Fig.7] illustrates an exploded view of a ballasting device according to a second embodiment of the invention;

[0070] [Fig.8] [Fig.8] illustrates a sectional view of the device of [Fig.7] according to a plane median passing through a key;

[0071] [Fig.9] [Fig.9] illustrates a sectional view of the device of [Fig.7] according to plans perpendicular to the keys;

[0072] [Fig. 10] [Fig. 11] Figures 10 and 11 illustrate detailed views of the installation of locking insert in locking cavities of a weighting element;

[0073] [Fig. 12] [Fig. 12] illustrates a detail view of the distal end lock of a key by means of a pin;

[0074] [Fig. 13] [Fig. 13] illustrates a cross-sectional view of the device of [Fig.7];

[0075] [Fig. 14] [Fig. 14] illustrates a flowchart of a method of securing to a chain of a weighting device according to the invention.

[0076] 6. Description of particular embodiments

[0077] 6.1. Examples of chain weighting devices

[0078] 6.1.1. Pins held by shutter plates

[0079] A first example of a chain ballasting device according to the invention is presented in relation to Figures 1 to 6.

[0080] Such a device comprises one or more ballast elements 10, also called barrels, and securing means 11 for securing the ballast element(s) 10 along a chain 12, for example to keep it ballasted in an underwater or more generally subaquatic environment.

[0081] The ballast elements 10 comprise a single-piece body 100. This means that the body 100 of the ballast elements 10 is formed from a single piece but is not made by assembling several elements. This body 100 is preferably made of cast iron (grey cast iron or other suitable cast iron). However, it could alternatively be made of cast steel.

[0082] Each ballast element 10 is crossed by a hole 101 arranged along a longitudinal axis X of the ballast element 10. As will be detailed later, this hole 101 allows the passage of a chain 12.

[0083] Each ballast element 10 also has at least two locking housings 102 arranged orthogonally to the longitudinal axis X of the corresponding ballast element 10. These locking housings 102, which in this embodiment are two in number, are arranged on either side of the hole 101. These locking housings 102 have an open end 1021 from which they extend inside the single-piece body 100 to their opposite end which is blind. In a variant, which will be described later, the locking housings may be open-ended. They open laterally inside the hole 101 of the corresponding weighting element and thus form open areas 1022 in the hole 101. Their section, orthogonal to their longitudinal axis X, is preferably quadrangular, in particular rectangular or square or other. It could also be circular or other.

[0084] These locking housings 102 each allow a securing key 11 to be housed. The open end 1021 of each locking housing 102 thus constitutes an open end for the introduction and extraction of a securing key 11.

[0085] The one-piece body 100 of the ballast element 10 comprises, upstream of each open end 1021 of each locking housing 102, a locking cavity 103. These locking cavities have a larger section, in a plane orthogonal to the axis of the locking housings 102, than the section in this plane of the locking housings 102. They have a bearing surface 104 which extends essentially originally to the axis of the locking housings 102.

[0086] The securing keys 11 have a shape complementary to the locking housings 102. They have a length substantially equal to the depth of the locking housings 102 between the open end 1021 and the blind end. When they are housed in the locking housings 102, they protrude, through the open areas 1022, inside the hole 101 of the corresponding ballast element 10. They can be made of steel, preferably stainless steel.

[0087] Closure plates 1200 make it possible to close the open ends 1021 of the locking housings 102 to hold the securing keys 11 in the locking housings 102. Each closure plate 1200 is in the form of a plate which is placed inside one of the locking cavities 103 while being held in contact against the bearing surface 104. The closure plates 1200 are preferably secured to the corresponding ballast element 10 by means of steel screws, preferably stainless steel. They are themselves preferably made of steel, ideally stainless steel. The closure plates could alternatively be secured to the ballast element by welding.

[0088] Each plate could be secured to the corresponding key and form a single piece with it.

[0089] The ballast device 10 further comprises as many drawer(s) 13 as ballast element(s) 10.

[0090] Each drawer 13 is intended to be housed in the hole 101 of a ballast element 10.

[0091] Each drawer 13 comprises two half-drawers 131. The half-drawers 131 are capable of being assembled to delimit an interior housing 1310 shaped to house a link 120 of a chain 12 to be ballasted. The half-drawers 131 have centering pins 132 and centering housings 133 capable of cooperating two by two to allow the half-drawers 131 to be centered during their assembly and to take up shear forces.

[0092] The contact between the two half-drawers is flat. This makes it possible to avoid the formation of a clearance between the two half-drawers. Such a clearance would induce a clearance between the half-drawers 131 and the single-piece body 100 which is not desired in particular since a clearance is already provided between the internal housing 1310 and the chain link 120 housed inside.

[0093] The hole 101 of each ballast element 10 preferably has a truncated inner peripheral contour along the longitudinal axis X. It therefore has one end of large diameter and one end of smaller diameter. In this case, the slide 13 has a truncated outer contour of a shape complementary to the inner peripheral contour of the hole 101. It therefore has one end of large diameter and one end of smaller diameter. The slide 13 is thus capable of being assembled to the ballast element 10 at least in part by a conical assembly. This makes it possible to limit or even eliminate the shear in the securing keys 11 in the main direction of stress, the body of the ballast element 10 then taking up the stress induced by the slide 13 when the link 120 of the chain 12 acts on the slide 13 (linked to the dynamics of the anchor line).

[0094] The taper of the hole 101 is made according to the arrow in the drawings (see figures 1, 2, 5 and 7), i.e. the diameter of the hole 101 narrows in the direction of this arrow. This arrow, which represents the main direction of stress, is oriented in the direction of the main forces induced on the ballast elements. These forces are oriented towards the element ballasted with the chain, i.e. towards the surface of the ocean during ballast in a marine environment. The truncated cone shape of the hole 101 and the drawer 13 makes it possible to take up the forces so that the keys 11 do not undergo shearing in the direction of the main forces. On the other hand, in the opposite direction to the main forces, the keys undergo shearing. The taper of the hole 101 and the drawer 13 makes it possible to avoid play between the drawer 13 and the single-piece body 100 and to transmit the force directly in the main direction of the forces.

[0095] In variants, the hole 101 of the ballast elements 10 like the drawers 13 may not have a truncated cone-shaped outline so that they will not be assembled by a conical assembly although this is preferred.

[0096] Two notches 134 are provided at the periphery of each drawer 13, orthogonal to the longitudinal axis. These notches 134 coincide with the locking housings 102, more precisely with the open areas 1022 in the hole 101, when the drawer 13 is in the hole 101 of a ballast element 10. These notches 134 thus allow the passage of the securing keys 11, i.e. their part forming a projection inside the hole 101 of a ballast element 10 when they are housed in the corresponding locking housings 102. More precisely, each notch comprises two opposite surfaces 1341 which extend in planes orthogonal to the axis X of the hole 101. When a key 11 is housed in a locking housing 102, then one of its two opposite sides is likely to be in abutment against one of the surfaces 1341 of the corresponding notch 134. Thus, the keys 11 block the drawer 13 in translation in the hole 101.

[0097] When a drawer 13 is housed in a hole 101 of a ballast element 10 and securing keys 11 are housed in the corresponding locking housings 102, these securing keys 11 extend outside the internal housing 1310 of the drawer 13 capable of housing a link 102 of a chain 12. In other words, the keys do not pass through the internal housing 1310 nor the link which is housed therein, if any. Thus, this link 120 is not in contact with the securing keys 11. This contributes to limiting the OPB / IPB and abrasion stresses experienced by the link 120 of the chain 12 housed in the drawer 13 and by the adjacent links 120.

[0098] The inner housing 1310 of each drawer 13 has an imprint 1311 of a shape complementary to a link 120 of chain 12. This inner housing 1310 is thus shaped to retain the weighting element 10 on the link 120 housed in the inner housing 1310 of the drawer 13 by contact on the outer peripheral contour of the link 120 (outer crown of the link).

[0099] The inner housing 1310 is dimensioned such that a clearance exists between the link housed in the inner housing 1310 and the drawer 13. In this way, when a ballast element, used to ballast a chain, strikes the ground, the ballast element does not transmit any force to the link that it houses, and the link / housing interaction is limited to the stresses induced by the link's own mass.

[0100] Furthermore, the drawer 13 comprises at each of the ends of the housing 1310 a clearance 1312 shaped to allow free rotation of the links 120 of the chain 12 secured to the link 120 housed in the housing 1310 of the drawer 13.

[0101] The drawer 13 and the securing keys 11 constitute means for securing the chain 12 to the ballast element 10.

[0102] The drawer 13 and the keys 11 participate in the ballast like the single-piece body 100.

[0103] In a variant, play-compensating means may be implemented so as to fill the play between the drawer 13 and the single-piece body 100 and thus prevent them from moving relative to each other when they are assembled.

[0104] In this case, the keys 11 have an inclined side 110 forming a bevel (beveled side) arranged opposite a non-beveled side.

[0105] The beveled side 110 of each of the keys 11 is arranged on the side of the large diameter ends of the drawer 13 and of the hole 101, and the section of the keys 11 tends to decrease in the direction of one end of the locking housings 102 opposite their open end 1021.

[0106] The locking housings 102 of the weighting element also have a beveled surface oriented towards the large diameter side of the hole located opposite a non-beveled surface.

[0107] The notches 134 of the drawer do not have a beveled surface.

[0108] The inclination of the beveled side 110 of each of the keys 11 is complementary to the beveled surface of the corresponding locking housing 102.

[0109] The beveled surfaces 110 of the keys 11 and the locking housings 102 are provided to come into contact with each other when a key 11 is inserted into a locking housing 102. The inclination of the beveled surfaces of the keys and the locking housings is configured so that these surfaces act against each other when the keys 11 are inserted into the locking housings 102 so as to induce a movement of the small diameter end of the drawer 13 towards the small diameter end of the hole 101.

[0110] When a key is inserted into a locking housing, the non-beveled side of this key located opposite its beveled side, acts against the corresponding surface of the drawer notch, but not on the weighting element, and the beveled side of the key does not come into contact with the drawer notch.

[0111] Alternatively, the beveled side of each key, as well as of the weighting element and the drawer, could be oriented towards the small diameter ends. In this case, the beveled side of each key would act against the corresponding surface of the notch of the corresponding drawer upon insertion of the key 11 into the locking housing 102 and would move the small diameter end of the drawer 13 towards the small diameter end of the hole 101.

[0112] Thus, along its longitudinal axis, each key has three sides perpendicular two by two and a fourth side inclined in such a way that the cross-section of the key decreases in the direction of its end intended to go into the bottom of the corresponding locking housing 102, i.e. at its blind end. 6.1.2. Pins held by inserts

[0113] A second example of a chain ballasting device according to the invention is presented in relation to figures 7 to 13.

[0114] We will now describe below the main differences between this second example and the first example which has just been described.

[0115] In this example, the means for securing the keys do not include a plate for closing the locking housings in which the keys are inserted. According to a different approach, the securing means include locking inserts 20, each key being held in position relative to the ballast element by means of an insert.

[0116] A locking insert 20 comprises a body 201 that is essentially a rectangular parallelepiped.

[0117] The body 201 of the insert is crossed by an internal light 202 allowing the passage of a key 11 through the insert 20. This internal light 202 is arranged between two opposite surfaces 203 of the body along the axis of the keys 11.

[0118] Each locking insert 20 is designed to be housed inside a locking cavity 103 formed in the weighting element 10 upstream of the locking housings 102. There are therefore as many locking cavities as there are keys.

[0119] Each locking cavity 103 has a lateral opening 104' for introducing an insert 20 along an axis orthogonal to the axis of the keys 11 and to the axis of the hole 101. Each lateral opening 104' is delimited, along the axis of the keys 11, by two bearing surfaces 105, 106 against which the two opposite surfaces 203 of an insert 20 can come to bear depending on the constraints imposed during the assembly of the key. The first bearing surface 106 is arranged on the side of the corresponding locking housing 102 while the second bearing surface 105 is arranged opposite the first bearing surface 106.

[0120] When a key 11 is housed in a locking housing 102, its end located in the region of the open end 1021 of the locking housing 102 projects inside the lumen 202.

[0121] It is possible to attach a jack to each insert to allow the keys to be stressed, leading to the small diameter end of the drawer being moved towards the small diameter end of the hole in the ballast element, as will become more clear on reading the description of a method according to the invention.

[0122] In this case, each insert 20 comprises means for reversibly securing, to the body of the insert 20, a jack body 30 having a piston (not visible) capable of acting on the key 11 along the axis of the key to complete its insertion and constrain it in the corresponding locking housing 102.

[0123] In this embodiment, the cylinder body 30 comprises a circumferential groove 301 at its end. In this case, the means for securing the cylinder body comprise two axes 40 which are housed in holes 41 passing through the body of the insert 20 near the surface 203 located opposite that located near the opening 1021 of the locking housing 102.

[0124] The locking inserts 20 are secured to the corresponding key by welding.

[0125] In this case, each insert 20 is open, by its wall accessible from the periphery of the device, by a passage 204 opening into the interior light 202 in a region where the end of the key 11 projects there. This passage 204 houses a weld bead (not shown) for securing the insert 20 to the key 11 by plugging.

[0126] As in the first embodiment, the locking housings 102 may be blind. However, the locking housings 102 are preferably open-ended.

[0127] In this case, each key 11 has a distal end 111 which projects, outside the corresponding locking housing 102, beyond an emerging end 1022 of the locking housing 102 arranged opposite the open end 1021. Locking means are then secured to the end 111 of the key 11 to prevent it from coming out of its locking housing 102 if the locking insert 20 were to become detached from the weighting element 10, or in order to replace the inserts. Generally, these locking means comprise, for each key, at least one locking element having at least one dimension greater than at least one dimension of the emerging end 1022 such that it cannot pass through the latter.

[0128] In the example illustrated in [Fig. 12], the locking element comprises a U-shaped elastic pin 42 comprising two branches 420 connected by a crosspiece 421. The crosspiece 421 is free to press against the key 11 or to move to a locking surface 1090 described below, and the two branches 420 are housed in grooves 1111 provided on two opposite sides of the distal end 111 of the key 11.

[0129] In this case, the weighting element 10 comprises reservations 109 each making it possible to house the distal end 111 of a key 11 and the locking element. In the case of the pins, this reservation 109 comprises a locking surface 1090 which extends essentially orthogonally to the branches 420 and the distance between the key and this locking surface is chosen, as a function of the length of the branches 420, so that if the crosspiece 421 comes to bear against the locking surface 1090, the branches 420 are always in their housing (groove 1111). This guarantees that the pins remain integral with the corresponding key in all circumstances and thus ensure their locking function in the position of this key.

[0130] The pin 42 and the grooves 110 could be respectively replaced by a bolt whose screw would pass through a hole passing through the distal end of the key 11, or any other relevant pinning system.

[0131] The variant which has just been described, with open-out locking housings and locking means, could also be implemented within the framework of the first embodiment, as a safety lock for the keys or as a replacement for the closure plates 1200.

[0132] The device may comprise means for self-centering the drawer 13 in the hole 101. Such self-centering means may facilitate the insertion of the drawer into the hole.

[0133] In this embodiment, these self-centering means comprise: - a guide element 135 secured to the drawer 13, this guide element 135 comprising two first opposite guide surfaces 1350 forming an angle relative to a plane passing through the axis of the hole 101 and tightening towards each other in the direction of a small diameter end 136 of the drawer 13; - a receptacle 107 formed in the ballast element 10 along the axis of the hole 101, the receptacle 107 comprising two second opposite guide surfaces 1070 parallel to a plane passing through the axis of the hole 101 of the ballast element 10, this receptacle 107 being capable of housing the guide element 135.

[0134] This variant with means of self-centering the angularity of the drawer relative to the barrel can be implemented within the framework of the first embodiment.

[0135] With reference to [Fig. 13], the half-drawers 131 can be crossed by a countersunk hole 1313 at the entrance of each of which there is a housing 1314. When the half-drawers 131 are assembled to form the drawer 13, the holes 1313 extend in the axis of one another. They allow the passage of a bolt (not shown) to secure the two half-drawers 131 to each other. The housings 1314 allow the head of the screw and the nut of the bolt to be housed so that they do not protrude from the surface of the drawer 13, the screw not penetrating into the internal link imprint of the drawer.

[0136] This variant can be implemented within the framework of the first embodiment.

[0137] 6.2. Example of a method of securing a device to a chain ballast

[0138] To work towards securing a ballast device to a chain, a securing method is implemented.

[0139] Such a method is presented in relation to [Fig.14].

[0140] Such a method comprises at least: - a step 50 of passing said chain 12 through at least one hole 101 of at least one ballast element; a step 51 of positioning at least one pair of half-drawers 131, forming at least one drawer, around at least one link 120 of the chain 12 to be ballasted so as to house the at least one link 120 in the at least one housing 1310 formed by the at least one pair of half-drawers 131; - a step 52 of inserting at least one drawer 13 into the hole 101 of at least one ballast element 10 (or conversely placing a ballast element around a drawer); - a step 53 of securing the drawer 13 to the ballast element 10.

[0141] More commonly, the chain will be weighted by means of a plurality of weighting elements arranged at essentially regular intervals.

[0142] In this case, step 50 consists of passing the chain through the holes 101 of several weighting elements spaced apart from each other.

[0143] Several pairs of half-drawers are then positioned, in step 51, around several links, each pair of half-drawers being arranged between two ballast elements 10.

[0144] Step 51 of positioning the half-slides 131 around one or more links 120 of the chain 12 to be ballasted consists of bringing the two half-slides 131 of each pair on either side of a link 120 of the chain 12 and bringing them together to make their centering pins 132 and their centering housings 133 cooperate and thus constitute the internal housing 1310 in which the link 120 of the chain 12 is then housed. This link 120 is then located in the imprint 1311 formed by the union of two half-slides 131. If necessary, the two half-slides 131 are secured to each other by means of a bolt passing through the holes 1313.

[0145] Step 52 of inserting each drawer 13 into the hole 101 of a ballast element 10 consists of slidingly inserting the drawer 13, in which there is a link 120 of the chain 12, into the hole 101 of a ballast element 10 until the notches 134 are in the extension of the locking housings 102 of the ballast element 10, and in particular in the extension of its open zones 1022 (or vice versa if it is the ballast element which is slid around the drawer.

[0146] The drawers are inserted into the holes of the ballast elements by sliding the chain through the holes (or vice versa).

[0147] When the hole 101 and the ballast element 10 respectively have inner and outer contours of truncated cone shape, this step thus makes it possible to obtain a conical type assembly.

[0148] During the insertion of a drawer 13 into a hole 101 (or vice versa), the first guide surfaces 1350 of the guide element 135 slide against the second guide surfaces 1070 of the receptacle 107 so that the drawer 13 is self-centered (in relative angularity) in the hole 101.

[0149] The securing step 53 consists of inserting the locking keys 11 into the locking housings 102 from the insertion openings 1021. The keys locking 11 then protrude into the hole 101 at the level of the open areas 1022 and are inserted into the notches 134. Each drawer 13 is thus locked inside the hole 101.

[0150] When the keys 11 are inserted into their locking housings 102, their beveled side acts on the beveled surface of the corresponding locking housing, but not on the drawer, and their non-beveled surface acts on a non-beveled surface of the notches 134 of the drawer, but not on the ballast element, such that the movement of insertion of the keys 11 into their locking housing 102 is transformed into a translation movement of the drawer 13 inside the hole 101 along the axis of the hole 101. This makes it possible to bring the small diameter end 136 of the drawer 13 closer to the small diameter end 108 of the hole 101 of the ballast element 10 and thus to take up the play between the drawer and the ballast element.

[0151] According to the first embodiment, the openings 1021 are then closed by means of the closing plates 1200 which are secured to the ballast element 10 by means of screws or by welding.

[0152] According to the second embodiment, prior to inserting the keys 11 into the locking housings 102, the locking inserts 20 are inserted laterally into the locking cavities 103 through the lateral openings 104'. The lower surface 203 of the locking inserts 20 is then applied against the lower bearing surfaces 106 of the locking cavities 103 under the effect of gravity. Thus, the locking inserts 20 are blocked in translation in the locking cavities 103 along axes parallel to the axes of the keys 11

[0153] The keys 11 are then inserted into the locking housings 102 by passing through internal slots 202 of the locking inserts 20. Their distal end 111 opens outside the corresponding locking housing 102 while their opposite end projects inside the internal slot 202 of the corresponding locking insert 20, in the axis of the corresponding passage 204. The end of the body of a jack 30 is reversibly secured to each locking insert 20 by means of the pins 40 passing through the holes 41 and the groove 301. The rod (not shown) of the jack is deployed towards the end of the key 11 located in the insert 20 and pushes on the key 11 to finish putting it in place in its locking housing 102 and take up the play between the drawer and the hole in the ballast element.During deployment of the cylinder rod, the upper surface 203 of the insert comes into contact with the upper bearing surface 105 of the cavity. During this stressing, a weld bead is made in the passage 204 of each insert 20 to secure each insert 20 in place, bearing on the surface 105. The key is thus held in the stressed position relative to the part weighting element. its welding on the insert which rests on the upper bearing surface 105 of the cavity of the ballast element. The rod of the jack is retracted and the body of each jack is separated from the corresponding insert 20 by removing the pins 40.

[0154] When a key is pressed into its locking housing against the bearing surfaces of the ballast element, the drawer and the corresponding insert, and permanently held under pressure by welding, the corresponding insert is pressed against the second surface.

[0155] A pin 42 is then placed at the distal end 110 of each key 11.

[0156] Such a pinning system may also be implemented in the first embodiment and may not be implemented in the second embodiment. 6.3. Variants

[0157] In the embodiments which have just been described, the drawer is secured to the ballast element by means of a pair of keys. In variants, the drawer may be secured to the ballast element by means of a single key although it is preferable to use a pair. It could also be secured to the ballast element by means of more than two keys. The number of locking housings, closure plates, inserts, cavities, notches, etc. will of course be defined according to the number of keys used.

Claims

Claims

1. Device for ballasting a chain 12, in particular in an underwater environment, said device comprising at least: - a single-piece ballasting element 10, said ballasting element 10 being crossed by a hole 101 formed along a longitudinal axis X of said ballasting element 10 and allowing the passage of said chain 12; - means for securing said chain 12 to said ballasting element 10; characterized in that said securing means comprise: - a drawer 13 comprising two half-drawers 131 capable of being assembled to delimit an internal housing 1310 shaped to house a link 120 of said chain 12; - at least one securing key 11 of said drawer 13 to said ballasting element 10 without interaction with said chain 12.

2. Ballast device according to claim 1 comprising means for taking up play between said keys 11 and said drawer 13.

3. Ballast device according to claim 1 or 2 wherein said hole 101 of said ballast element 10 has a frustoconical peripheral contour along said longitudinal axis X, said drawer 13 having a frustoconical external contour of a shape complementary to said peripheral contour of said hole 101, said drawer 13 thus being capable of being assembled to said ballast element 10 at least in part by a conical assembly.

4. Device according to any one of claims 1 to 3 in which at least one locking housing 102 is provided in said ballast element 10 orthogonally to said longitudinal axis X, said at least one locking housing 102 making it possible to receive said at least one key 11.

5. Device according to claim 4 in which at least one notch 134 is provided on the periphery of said drawer 13 orthogonally to said longitudinal axis X, said at least one notch 134 allowing the passage of said at least one key 11.

6. Device according to any one of claims 1 to 5 wherein said at least one key has an essentially quadrangular section.

7. Device according to claim 2 alone or in combination with any one of claims 3 to 6, wherein said at least one key 11 has a beveled side located opposite a non-beveled side, the inclination of said beveled side of said at least one key being configured to act against said weighting element and said non-beveled side being configured to act against one of said notches of said drawer housing said at least one key, during an introduction of said at least one key into said at least one locking housing and move a small diameter end of said drawer towards a small diameter end of said hole.

8. Device according to claim 7 in which said at least one locking housing 102 has an open end 1021 for insertion and extraction of said at least one key 11, said beveled side of said at least one key being arranged on the side of said large diameter ends of said drawer and of said hole, the section of said at least one key 11 tending to decrease in the direction of one end of said at least one locking housing 102 opposite their open end 1021.

9. Device according to any one of claims 4 to 8 wherein said securing means comprise at least one closure plate 1200 of said at least one open end 1021 to hold said at least one key 11 in said at least one locking housing 102.

10. Device according to any one of claims 4 to 8 wherein said securing means comprise at least one insert for locking said at least one key, said at least one locking insert being placed in a locking cavity of said ballast element, each locking cavity having a lateral opening for introducing said insert along an axis orthogonal to the axis of said at least one key and to the axis of said hole, and being delimited, along the axis of said at least one key, by a first bearing surface oriented towards said at least one locking housing and a second bearing surface opposite said first bearing surface, said at least one insert being located bearing against said second surface when a key is housed in said corresponding locking housing, said at least one locking insert having an internal light for passage of said at least one key, one end of said at least one key projecting inside said light when it is housed in said locking housing.

11. Device according to claim 10 in which said at least one insert comprises means for reversibly securing to said insert a cylinder body having a piston capable of acting on said at least one key along the axis of said at least one key to insert it and place it under stress in said at least one corresponding locking housing.

12. Device according to any one of claims 9 to 11 in which said at least one closure plate 1200 is secured to said ballast element 10 by screwing or welding and / or said at least one insert is secured to said at least one key by welding.

13. Device according to claim 10 or 11 in which said at least one insert is crossed by a passage opening into said interior light in a region of said end of said at least one key forming a projection therein, said passage housing a weld bead for securing said at least one insert by plugging to said at least one key.

14. Device according to any one of claims 4 to 13 in which said at least one locking housing is blind.

15. Device according to any one of claims 4 to 13 in which said at least one locking housing is open-ended.

16. Device according to claim 15 in which each key has a distal end which projects, outside said corresponding locking housing, beyond an emerging end of said locking housing arranged opposite said open end, said device comprising means for locking said key, said locking means comprising at least one locking element integral with said distal end, said at least one locking element having at least one dimension greater than at least one dimension of said emerging end.

17. Device according to any one of claims 3 to 16 comprising means for self-centering the angularity of said drawer in said hole, said self-centering means comprising: - a guide element secured to said drawer, said guide element comprising two first opposite guide surfaces forming an angle relative to a plane passing through the axis of said hole and tightening towards each other in the direction of a small diameter end of said drawer; - a receptacle formed in said ballast element along the axis of said hole, said receptacle comprising two second opposite guide surfaces parallel to a plane passing through the axis of said hole of said ballast element, said receptacle being capable of housing said guide element.

18. Device according to any one of claims 1 to 17 wherein said at least one key 11 extends outside said internal housing 1310 of said drawer 13 so that it does not pass into said internal housing 1310 nor through a link 120 of chain 12 where appropriate housed therein.

19. Device according to any one of claims 1 to 18 in which said inner housing 1310 of said drawer 13 is shaped to retain said weighting element 10 on said link 120 housed in said inner housing 1310 of said drawer 13 by contact on the outer peripheral contour of said link 120.

20. Device according to any one of claims 1 to 19 in which said drawer 13 comprises at each of the ends of said internal housing 1310 a shaped clearance 1312 to allow free rotation of the links 120 of said chain 12 secured to said link 120 housed in said internal housing 1310.

21. Method for securing to a chain 12 a ballast device according to any one of claims 1 to 20, said method comprising at least: - a step of passing said chain through at least one hole of at least one ballast element; - a step of positioning at least two half-drawers 131, forming at least one drawer, around at least one link 120 of said chain 12 so as to house said at least one link 120 of said chain 12. at least one link 120 in at least one interior housing 1310 formed by said at least two half-drawers 131; a step of inserting said at least one drawer 13 into said at least one hole 101 of said at least one ballast element 10, or vice versa; a step of securing said at least one drawer 13 to said at least one ballast element 10.

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