Detachable drive unit for water

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of finning devices. Its application is particularly advantageous in the field of underwater diving. STATE OF THE ART

[0002] In the aquatic environment, several devices exist to assist swimmers. In particular, fins make swimming easier for divers by increasing their surface area in the water. However, traditional fins have limitations because they place significant stress on swimmers' ankles, potentially leading to overuse injuries, sprains, and strains.

[0003] There are solutions to overcome this problem, such as the one described in document FR3069443A1, which notably describes a fin blade connected to the shin of a diver, so that the thrust force is generated by the diver directly through the leg muscles and the tension is no longer concentrated at the ankles.

[0004] It turns out that in practice this solution only provides limited propulsion. Furthermore, this solution proves inconvenient to use because, for example, the fin blade cannot be easily attached or detached underwater.

[0005] An object of the present invention is therefore to propose a reliable solution to overcome this problem related to excessive stress on the ankles, allowing for improved propulsion and offering easy handling underwater.

[0006] The other objects, features, and advantages of the present invention will become apparent from an examination of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY OF THE INVENTION

[0007] To achieve this objective, according to one embodiment, an aquatic propulsion device is provided, configured to be worn on at least one leg of a swimmer and comprising: at least a first portion configured to attach securely to the leg of a user, the first portion comprising: a first support piece having a first internal face shaped so as to come to rest on the tibia of the swimmer and a first external face opposite to the first internal face.

[0008] The device also includes a second part comprising: a wing for the propulsion of the swimmer, a second support piece carrying the wing and having a complementary part of the first support piece so that the device has: an attached configuration in which the second support piece cooperates with the first support piece to secure, preferably by removing all degrees of freedom, the second support piece to the first external face of the first support piece in order to transmit a finning effort from the first portion to the wing of the second portion, a detached configuration in which the cooperation of the second support piece with the first support piece is removed so that the second portion is completely detached from the first portion.

[0009] This allows the swimmer a walking or running configuration in which the wing is detached and can be carried by hand. It also allows the user to put on or take off the second portion underwater and potentially pass it to another diver, either underwater or above water.

[0010] Indeed, the device is configured to allow for easy joining of the first section with the second section. The coupling of the first and second sections is achieved via the first and second support pieces, which are in contact with each other, allowing the transmission of force from the user's tibia to the wing.

[0011] Without the present invention, an easy alternation between a walking configuration and a swimming configuration would not be possible for a user who would necessarily have to remove their entire device.

[0012] Prior art solutions are unsatisfactory for several reasons, including the fact that sails are complex to remove, especially underwater, and consequently they are in practice put on from a boat or from the shore.

[0013] Thus, the present solution not only offers a sailing configuration with the sail detached but also allows easy handling of the sail in and out of the water.

[0014] With this solution, it is now possible to overcome the problem of excessive strain on the ankles while allowing the use of a removable wing. BRIEF DESCRIPTION OF THE FIGURES

[0015] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which: There figure 1 represents a swimmer equipped on each leg with an example of a propulsion device according to the present invention in a swimming configuration. figure 2 represents an example of a propulsion device according to the present invention. The figures 3A to 3D represent the propulsion system illustrated in figure 2 comprising a first portion and a second portion, in various positions when the first and second portions are brought into cooperation. figure 4 represents a swimmer equipped with an example of a propulsion device according to the present invention in a walking configuration. figure 5 represents a particular example of a single-fin device according to the invention.

[0016] The drawings are given as examples and are not limiting to the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. DETAILED DESCRIPTION

[0017] Before beginning a detailed review of embodiments of the invention, optional features which may possibly be used in association or alternatively are stated below: According to an example, the device configured so that in attached configuration the second portion is secured to the first portion only by said cooperation between the second support piece and the first support piece.

[0018] According to one example, the first portion comprises a first attachment element and the second portion comprises a second attachment element complementary to the first attachment element, the actuation of one of the first and second attachment elements allowing alternating passage between: a locked configuration in which the first and second attachment members cooperate to lock the device in the attached configuration, and an unlocked configuration in which the first and second attachment members allow the device to move from the attached configuration to the detached configuration.

[0019] Thus, according to this example, the two organs are configured to cooperate with each other in order to: lock the second support piece onto the first support piece in the attached configuration, unlock the second support piece onto the first support piece in the detached configuration.

[0020] In one example, the first and second attachment members cooperate by clipping and / or via a latch mechanism.

[0021] Preferably, it is not a screw-nut connection.

[0022] According to one example, the device is configured so that the actuation of one of the first and second attachment organs is effected by a manipulation of that organ by the swimmer to switch from the attached configuration to the detached configuration.

[0023] According to one example, the actuation of one of the first and second attachment members is caused, preferably only, by the cooperation of the second portion on the first portion to pass from the detached configuration to the attached configuration.

[0024] Thus, the swimmer does not need to manipulate the attachment mechanism to attach the second portion to the first portion. They can therefore quickly switch to swimming mode, even in challenging conditions, for example, when in the water.

[0025] According to one example, the first portion includes a first pivot element, integral with the first support piece, and the second portion includes a second pivot element, the two pivot elements being configured to cooperate, preferably by interlocking, so as to move from the detached configuration to the attached configuration by tilting the second support piece relative to the first support piece.

[0026] Thus, the first pivot point and the second pivot point guide the relative movement of the second support piece with respect to the first support piece during the alternating transition between the detached and attached configurations. This facilitates user handling, which is particularly valuable in demanding situations, for example, when the swimmer is in or under the water and / or needs to act quickly.

[0027] According to one example, the first pivot member and the second pivot member are configured to guide the relative movement of the second support member relative to the first support member during the alternating transition from the detached configuration to the attached configuration, according to a rotation around a first axis substantially perpendicular to a principal direction of tibial extension.

[0028] According to one example, the device is configured so that the amplitude of the rotation by tilting of the second portion relative to the first portion is limited by the contact between the second inner face and the first outer face.

[0029] Preferably, the main direction extends parallel to the direction defined by the user's malleoli.

[0030] Thus, the first portion and the second portion can easily be assembled together.

[0031] In fact, this solution allows for improved propulsion for the swimmer, as well as easier assembly and disassembly of the wing underwater.

[0032] The solution allows the swimmer's ankles to move freely while providing improved propulsion. Ideally, the swimmer's ankles are guided in rotation along the main direction and laterally restrained by the wing supports.

[0033] According to one example, the two organs are configured so as to cooperate at the end of the tilting movement, when there is contact between a second internal face of the second portion with the first external face of the first portion.

[0034] In one example, one of the two fastening elements is operated manually without tools. Preferably, one of the two elements is operated with one hand. The two elements can be operated by pulling a latch, tab, or loop.

[0035] According to one example, in the attached configuration, the wing is positioned at a distance of at least 10 cm from the first support piece so as to provide in the second portion an opening allowing the user's foot to pass through said space.

[0036] According to one example, in the attached configuration, the wing extends substantially, in line with the direction of the user's tibia.

[0037] Advantageously, in the attached configuration, the device is configured so that the user's foot is located between the first portion and the second portion.

[0038] According to one example, the second portion includes at least one wing support connecting the second support piece to the wing, the wing support being capable of elastically deforming during its use, under the effect of a finning force applied by the user.

[0039] The wing support is advantageously shaped so as not to deform under the effect of its own weight.

[0040] The sail support is shaped so that, when immersed, it deforms under the effect of a finning effort applied by the user, then when this finning effort is removed, it returns to its rest position.

[0041] The wing support thus returns to the device some of the force that caused its deformation. This improves the device's performance.

[0042] According to one example, the device includes a third portion comprising an intermediate organ and equipment configured to accommodate at least partially the user's foot, the intermediate organ being articulated in rotation with the first portion along a first axis, and the equipment being articulated in rotation with the intermediate organ along an intermediate axis parallel to and not coincident with the first axis.

[0043] Preferably, the second intermediate axis is parallel to the first axis. Thus, when the device is worn by a user, the first axis is approximately aligned with the direction defined by the malleoli of the tibia and fibula of said swimmer. Preferably, it is projected along an anteroposterior axis of the user.

[0044] Preferably, the rotation of the third portion with the first portion may occur around an additional axis distinct from the first axis, but preferably substantially parallel to the first axis. The additional axis may be substantially parallel to the first axis and at a distance from it. Preferably, the additional axis and the first axis will coincide so as to be aligned with the swimmer's malleoli in a configuration where the device is worn.

[0045] According to one example, the second portion is configured so as to provide between the second support surface and the wing a space allowing, in attached configuration, the free movement of the third portion through said space and relative to the second portion.

[0046] According to one example, the equipment is an accessory, of the slipper type, comprising a closed profile configured to surround the user's foot, preferably at least at the level of the arch.

[0047] According to one example, the device has an additional wing attached to the equipment and configured to be positioned under the user's foot, the additional wing having a width dimension, along the first axis, substantially the same dimension as the width of the equipment.

[0048] This increases the swimmer's plantar surface area and thus further increases the propulsive effort when the water is pushed back with the sole of the foot.

[0049] Preferably, the additional wing has a length perpendicular to the width dimension of less than 30 cm. The reduced size of the second wing facilitates the swimmer's movement. The reduced size of the second wing also allows passage through the third section via the opening when the device is in the attached configuration.

[0050] Preferably, the second wing is glued under the equipment.

[0051] In one example, the wing is made of a first material having a Young's modulus E1 and the wing support is made of a second material having a Young's modulus E2, the first material and the second material being such that E1 <E2.

[0052] Preferably, the first material has less rigidity than the second material.

[0053] According to one example, the second portion includes at least two sail supports, preferably distributed symmetrically on each side of the sail and configured so as to support said sail.

[0054] Preferably, each wing support has: a proximal end defining with the first portion a pivot connection to form said joint in rotation of the second portion relative to the first portion along a first axis and a distal end.

[0055] The said opening extends from the proximal extremities towards the distal extremities. Preferably, the sail is supported by a distal part of the second portion, the distal part extending from the distal extremities.

[0056] The sail support can be in the form of a rod or a flat profile.

[0057] In one example, the first support piece is curved and configured to make contact with the front of the swimmer's leg, and the first portion includes a fastening system, preferably adjustable, configured to hold the first support piece in position against the front of the swimmer's leg, preferably against the swimmer's shin.

[0058] According to a particular embodiment, the bearing piece is supported by a rigid part of the first portion. Advantageously, the bearing piece has a concave surface.

[0059] In one example, the first support piece and the second support piece comprise complementary surfaces of curved shapes.

[0060] According to one example, at least one of the wing support and the wing is made of a composite material.

[0061] Preferably, the main direction of extension of the device extends, in the attached configuration, in line with the swimmer's tibia.

[0062] In one example, the second support piece has a curved surface so as to fit together with the first support piece.

[0063] According to one example, the device comprises two distinct initial portions configured respectively to be attached to each of the user's legs.

[0064] According to one example, the first two portions each comprise an attachment element configured to cooperate with a complementary attachment element carried by a single second portion configured to cooperate simultaneously with the first two portions, the second portion thus enabling the first two portions to be joined together in an attached configuration.

[0065] Thus, the device forms a monofin.

[0066] The term "finning movement" refers to the movement necessary to activate the device; it can be understood as a succession of oscillations of the swimmer's legs.

[0067] In this patent application, the term mobile corresponds to a rotational movement or a translational movement or a combination of movements, for example the combination of a rotation and a translation.

[0068] In this patent application, when two parts are described as distinct, it means that these parts are separate. They are: positioned at distances from each other, and / or mobile relative to each other and / or joined together by being fixed by added elements, this fixing being removable or not.

[0069] A single, monobloc part cannot therefore be made up of two separate parts.

[0070] In this patent application, the term "fixed" used to describe the connection between two parts means that the two parts are bound / fixed to each other with respect to all degrees of freedom, unless explicitly stated otherwise. For example, if it is stated that two parts are fixed in translation along a direction X, this means that the parts can move relative to each other except along the X direction. In other words, if one part is moved along the X direction, the other part moves in the same direction.

[0071] In this patent application, an elastic means may, for example, be a spring, such as a coil spring, elastic washers such as Belleville washers, an elastomer, or a rubber.

[0072] In the detailed description that follows, terms such as "horizontal," "vertical," "longitudinal," "transverse," "upper," "lower," "top," "bottom," "front," "back," "inside," and "outside" may be used. These terms should be interpreted relatively in relation to the position of the entire device worn by the swimmer and in a configuration in which the swimmer is standing on land or underwater.

[0073] In the context of the present invention, "fully decoupled" shall be understood for two parts "A" and "B" as the fact that there is no mechanical link between part "A" and part "B"

[0074] For example, the concept of "horizontal" can also correspond to a direction parallel to the level of the water or the ground.

[0075] The present invention relates to an aquatic propulsion device configured to be worn by a swimmer. The use of this type of device is particularly suitable for scuba diving and prolonged swimming efforts.

[0076] The present invention relates to a device comprising two independent fins, as illustrated in figures 1 to 4 It also applies to a monofin, that is, a fin comprising a blade moved simultaneously by both legs of the swimmer, as illustrated in figure 5 A first embodiment will now be described with reference to figures 1 to 4 All the characteristics, technical effects and advantages mentioned for this embodiment are perfectly transposable and combinable to a monofin type device.

[0077] As illustrated in the figure 1For example, when swimmer 2 is in a swimming configuration, he is simultaneously equipped with two propulsion devices 1 attached respectively to his two legs. According to the monofin embodiment, swimmer 2 is equipped with a single aquatic propulsion device 1, preferably attached to both legs 21 at the same time.

[0078] Advantageously, device 1 is configured so as to remain in position against the leg 21 of swimmer 2, for example at the level of the shin while leaving the ankle and foot free of any movement.

[0079] Device 1 is thus configured to be worn on leg 21 and preferably to be held in position against the shin. Preferably, device 1 is suitable for wearing on the lower part of leg 21, namely in an area between the ankle and the knee.

[0080] As illustrated in the figure 2and according to an example, the device 1 comprises a first portion 11 and a second portion 12. The first portion 11 being configured to allow the device 1 to be held in position on the leg 21. The second portion 12 being configured so as to attach and / or alternatively detach relative to the first portion 11 along the first axis X1. FIRST PORTION

[0081] As illustrated in the figure 3A and according to a particular embodiment, the first portion 11 includes a support piece 114. Advantageously the support piece 114 is supported by a rigid part of the first portion 11. The support piece 114 includes a first inner face 114a, preferably concave, configured to at least partially wrap around a portion of the leg 21 of the swimmer 2.

[0082] The first portion 11 may be a removable piece, configured to attach securely to the leg 20 of swimmer 2 and alternatively detach from it. The support piece 114 has a first inner face 114a shaped to bear against the tibia of swimmer 2 and a first outer face 114b opposite the first inner face 114a. The first inner face 114a may include a concave portion and / or the first outer face 114b may include a convex portion. SECOND PORTION

[0083] The second portion 12 preferably comprises a wing 121, a wing support 122, and the second support piece 124. The wing support 122 extends between the wing 121 and the second support piece 124 so as to mechanically transmit the forces exerted on the second support piece 124 to the wing 21. The wing 121 is integral with the wing support 122. The second support piece 124 is integral with the wing support 122 and is configured to allow the attachment of the second portion 12 to the first portion 11 so as to allow the device to transition from a detached configuration to an attached configuration in which the second portion extends along the preferred extension direction of the tibia Y21.

[0084] Preferably, when device 1 is worn by swimmer 2, the first axis X1 is substantially directed along the direction defined by the malleoli of the tibia and fibula of said swimmer 2.

[0085] The wing 121 is preferably located with respect to the plantar arch. The wing 121 being advantageously located in a portion of space delimited by a plane perpendicular to the preferred direction of extension of the tibia Y21 and passing through the plantar arch.

[0086] The second support piece 124 comprises a second internal face 124a opposed to a second external face 124b. The second internal face 124a is preferably shaped to formally couple with the first external face 114b. The second internal face 124a may have a concave portion suitable for positioning on a convex portion of the first external face 114b. SAIL SUPPORT

[0087] As illustrated in the figure 3A and, according to one example, each wing support 122 has: a proximal end 122a defining with the first portion 11 an attachment interface to allow the removability of the second portion 12 relative to the first portion 11, a distal end 122b to which the wing 121 is attached.

[0088] According to a particular embodiment, the device is configured so that the wing 121 and the wing support 122 can be attached together and / or detached, for example at the distal end 122b so as to allow optimized disassembly of the device for space-saving purposes.

[0089] The wing support 122 can be in the form of two profiled rods with a rectangular cross-section.

[0090] Advantageously, the wing support(s) 122 are in contact with the bottom of the support element 114 so as to create a reaction point and thus allow the movement of the leg 21 against the support element 114, resulting in an angular displacement of the wing 121. Preferably, at least one wing support 122 is configured to ensure that the second portion 12 is held in position on the first portion 11.

[0091] Preferably, the wing support(s) 122 are parts having a plane of symmetry. Advantageously, the wing support(s) comprise at least two rods, distributed parallel to each other around the wing 121. SPACE FOR FOOT PASSAGE

[0092] Device 1 is configured so that the wing 121 is positioned at a distance of at least 10 cm from the first axis X1 so as to provide in the second portion 12 a space 122c allowing the swimmer's foot 2 to pass through said space 122c when device 1 is in attached configuration.

[0093] Preferably, the passage distance is at least 15 cm, preferably at least 20 cm, advantageously between 20 and 25 cm.

[0094] The said space 122c extending from the proximal ends 122a towards the distal ends 122b. Preferably, the wing 121 is supported by a distal part of the second portion 12, the distal part extending from the distal ends 122b.

[0095] According to a particular embodiment, the wing 121 extends along the wing support 122.

[0096] Device 1 is configured to pass from: an attached configuration in which the wing 121 is configured to extend substantially, in line with the preferred extension direction of the tibia Y21 of the swimmer's leg 21, to a detached configuration, as illustrated in the figure 4 , in which the wing 121 is removed and can be carried easily and manually by swimmer 2.

[0097] The transition from the detached configuration to the attached configuration can be achieved by clipping the second portion 12 with the first portion 11.

[0098] In the attached configuration, the device 1 is configured so that the foot of the swimmer 2 is located between the second support piece 124 and the wing 121. Preferably, in the attached configuration, the main direction of secondary extension Y12 of the device 1 extends substantially in line with the tibia of the swimmer 2. The device 1 is in an attached configuration when the first portion 11 extends along the main direction Y11 substantially parallel to a preferred direction Y21 of tibia extension and the wing 121 extends parallel to the main direction Y11.

[0099] Preferably, the device is configured so that the second portion 12 is removable relative to the first portion 11. SWITCHING

[0100] As illustrated in Figures 3B And 3Cand according to an example, the first portion 11 and the second portion 12 are able to pivot relative to each other around the principal axis X1.

[0101] According to an example, the first portion 11 includes a first pivot organ 111 and the other between the first portion 11 and the second portion 12 includes a second pivot organ 120 complementary and able to cooperate by rotation with the first pivot organ 111 along the first axis X1.

[0102] The first pivot member 111 may be a rod comprising a head and a cylindrical body. The second pivot member 120 may be a notch adapted to cooperate by rotation with the first pivot member 111 about the first axis X1. ATTACHMENT ORGANS

[0103] According to a particular embodiment, the first portion 11 comprises a first attachment member 115 and the second portion 12 comprises a second attachment member 125. The first attachment member 115 and the second attachment member 125 are configured so as to maintain the device 1 in the attached configuration.

[0104] According to a particular embodiment, the first attachment member 115 is located at a proximal end of the first support piece 114. The second attachment member 125 may be located at a proximal end of the second support piece 124.

[0105] The securing mechanism between the first fastening element 115 and the second fastening element 125 is achieved, for example, by clipping. At least one of the fastening elements 115 or 125 may include a return spring, such as a spring. Alternatively, it may involve the joining of a ring and a hook.

[0106] Preferably, it will be a clipping system in which at least one of the first attachment member 115 and the second attachment member 125 comprises a female portion and the other of the first attachment member 115 and the second attachment member 125 comprises a male portion configured to cooperate by fitting with the female portion.

[0107] Advantageously, the male portion is cylindrical, preferably spring-mounted, preferably integral with the second portion 12 and / or able to extend in an attached configuration along the main extension direction Y21. The male portion may be located on the second external face 124b. SYMMETRICAL BICONVEX PROFILE SAIL

[0108] In a particular embodiment, the blade 121 has a profile shape with a symmetrical biconvex cross-section. This allows, in particular, for the least turbulent swimming possible. The present invention, combined with a blade with a symmetrical biconvex cross-section, makes it possible to capture a powerful rotational movement around the axis of the swimmer's knees, which allows the blade 121 to develop a significantly higher angular velocity than with a conventional fin. This angular velocity is advantageously enhanced and converted into thrust by the use of a blade with a symmetrical biconvex cross-section. A profile with a symmetrical biconvex cross-section, combined with circular displacement, preferably generates a higher flow velocity on the side exposed to the direction of rotation, called the extrados, and a lower velocity on the opposite side, called the intrados. This difference in flow velocity creates range and amplifies the angular velocity of the blade 121.Thus, thanks to the device of the present invention, it is possible to amplify the performance of propulsion and swimming techniques. THIRD PORTION

[0109] According to a particular embodiment, the propulsion device 1 includes a third portion 13. The third portion 13 can be rotationally articulated relative to the first portion 11 along an articulation axis such as the first axis X1. The third portion 13 may include equipment 13a configured to accommodate at least partially the foot of the swimmer 2.

[0110] The third portion 13 can be articulated in rotation relative to the first portion 11 along an articulation axis different from the first axis X1, preferably extending in a direction parallel to the first axis X1. The articulation axis can be at least 1 cm away from the first axis X1. The articulation axis can be in a configuration where the device is supported by the swimmer's malleoli.

[0111] The first axis X1 advantageously extends along the malleoli of swimmer 2. Preferably, the additional wing 131 has a lengthwise dimension, perpendicular to the widthwise dimension, and extends under the equipment 13a. The reduced size of the additional wing 131 facilitates swimming for swimmer 2 when the second portion 12 is detached. This increases the plantar surface area of ​​swimmer 2 and thus further enhances the propulsive force when the water is pushed away with the sole of the foot.

[0112] Preferably, the additional wing 131 is configured to be fixed by gluing under the equipment 13. Advantageously, the reduced dimension of the additional wing 131 also allows the equipment 13 to pass through said space 122c when the device 1 is in attached configuration. INTERMEDIATE ORGAN

[0113] According to one example, the third portion 13 comprises an intermediate organ 113 and a piece of equipment. The equipment is configured so as to at least partially envelop the foot of the swimmer 2 and the intermediate organ 113 is articulated in rotation with the first portion 11 along an axis of articulation, which may be the first axis X1, preferably the axis of articulation is parallel to the first axis X1, and the equipment is articulated in rotation with the intermediate organ 113 along a second intermediate axis X113, preferably parallel to the axis of articulation.

[0114] The intermediate component 113 can take the form of a connecting rod having a pivot joint about the first axis X1 and a pivot joint about the second intermediate axis X113.

[0115] Advantageously, equipment 13 is an accessory, of the slipper type, comprising a closed-loop profile configured to surround the swimmer's foot 2, preferably at least at the level of the arch of the foot. THE SAIL CONNECTION

[0116] According to a particular embodiment, the device includes a removable connection mechanism between the wing 121 and the additional wing 131. Indeed, this feature allows for a finer distribution of forces between the tibia 21 and the foot of the swimmer 2.

[0117] Preferably, the connection mechanism is removable. The connection mechanism may include a linking element such as a strap, cord, or elastic band. The connection may be made in a lower part of the equipment, specifically in the part of the equipment configured to be worn closest to the swimmer's foot 2. Preferably, it should be located as close as possible to the front of the swimmer's foot to establish a connection between the swimmer's toe and the wing 121. Thus, the connection mechanism allows for optimized distribution of forces on the anterior part of the swimmer's body 2, as well as appropriate management of the deformation of the second wing during the rotational movements of the device 1.

[0118] In a preferred embodiment, the device is configured to adapt to very different swimmer body types, distributing swimming effort between the foot and the lower leg. These features characterize the invention in its use during swimming, but the concept also allows for innovations for use out of water or in different environments. MATERIALS AND STRENGTH

[0119] As an example, the wing supports 122 are shaped so as not to deform under the effect of their own weight.

[0120] According to one example, the sail supports 122 are shaped so that, when they are immersed and deformed under the effect of a finning effort applied by the swimmer 2 and then this finning effort is removed, they can return to their resting position.

[0121] The wing supports 122 thus return to the device some of the force that caused their deformation. This improves the device's performance.

[0122] In one example, the wing 121 is made of a first material having a Young's modulus E1 and the wing support 122 is made of a second material having a Young's modulus E2, the materials being such that E1 <E2.

[0123] According to a particular embodiment, the wing 121 has a lower stiffness than the wing supports 122 so that the wing is stiffened by the wing supports 122. MONOPALM DEVICE

[0124] As illustrated in the figure 5and according to one example, the device is configured to allow the attachment of a single second portion 12 simultaneously with two first portions 11 suitable for being worn by the swimmer 2. In other words, according to this embodiment, the device 1 comprises two distinct first portions 11,11' configured respectively to be attached to each of the legs of the swimmer 2.

[0125] Preferably, the first two portions 11,11' each comprise an attachment member 115, 115' configured to cooperate respectively with two complementary attachment members 125, 125' carried by the second portion 12, so as to allow alternatively the passage of the device 1 between the detached configuration and the attached configuration.

[0126] In this particular embodiment, the second support piece 124 carrying the wing 121 may have two parts respectively complementary to the first support pieces 114, 114 of the first two portions 11, 11' so that the device presents: an attached configuration in which the second support piece 124 cooperates simultaneously with two first support pieces 114 of two distinct first portions 11, 11' so as to fix, preferably by removing all degrees of freedom, in a removable manner, the second support piece 124 on the first external faces 114b of the first support pieces 114 in order to transmit a finning force from the first portion 11 to the single wing 121 of the second portion 12, a detached configuration in which the cooperation of the second support piece 124 with the first support pieces 114 is removed so that the second portion is completely detached from the two first portions 11, 11'.

[0127] Preferably, the second portion 12 comprises at least one organ from the first pivot organ 111 and the second pivot organ 120, preferably exactly two organs from the first pivot organ 111 and the second pivot organ 120.

[0128] In this embodiment, the sail support 122 in attached configuration extends between the legs of swimmer 2, at the center of the first two portions 11, 11'. The sail support 122 may in this case comprise a single profile.

[0129] According to one embodiment, the second portion 12 is capable of cooperating by tilting simultaneously with at least two other components from among the first pivot component 111 and the second pivot component 120 carried respectively by the first two portions 11, 11'. Preferably, in a worn configuration of the monofin device, the pivot components 111, 120 are located between the legs of the swimmer 2. The second portion 12 may include a blade support 122 between the swimmer's legs such that the first two portions are distributed on either side of the blade support 122. OTHER METHODS OF IMPLEMENTATION

[0130] According to a particular embodiment, the device 1 includes sensors configured to trigger an actuator to generate a movement of the fins 121 according to the position of the leg(s) of swimmer 2 or according to the oscillatory movement of swimmer 2.

[0131] The first portion 11 advantageously includes an attachment system 23 allowing the propulsion device 1 to be secured to the leg 21 of the swimmer 2. The attachment system 23 may be at least one strap, preferably elastic.

[0132] The invention is not limited to the embodiments described above and extends to all embodiments covered by the claims. REFERENCES

[0133] 1 aquatic propulsion device 11 first portion 111 first pivot point 114 first support piece 114a first inner face 114b first outer face 115 first attachment point 11' first additional portion 12 second portion 12' fin support 120 second pivot point 121 blade 122 blade support 122a proximal end 122b distal end 122c gap 124 second support piece 124a second inner face 124b second outer face 125 second attachment point 13 third portion 13a equipment 2 swimmer 21 leg 22 foot 23 attachment system Y11 main direction Y21 preferred direction of tibial extension, X1 first axis X113 intermediate axis

Claims

1. Aquatic propulsion device (1) configured to be worn at least at one leg (21) of a swimmer (2) and comprising: - at least one first portion (11) configured to be securely attached to the leg (21) of a user (2), the first portion (11) comprising: - a first bearing part (114) having a first inner face (114a) shaped so as to bear on the tibia of the swimmer (2) and a first outer face (114b) opposite to the first inner face (114a), characterised in that the device (1) also comprises - a second portion (12) comprising: o a foil (121) for propelling the swimmer, o a second bearing part (124) carrying the foil (121) and having a portion complementary to the first bearing part (114) so that the device (1) has: ▪ an attached configuration in which the second bearing part (124) cooperates with the first bearing part (114) to removably secure the second bearing part (124) on the first outer face (114b) of the first bearing part (114) in order to transmit a palming force from the first portion (11) to the foil (121) of the second portion (12), ▪ a detached configuration in which the cooperation of the second bearing part (124) with the first bearing part (114) is eliminated so that the second portion (12) is completely disengaged from the first portion (11).

2. Device (1) according to the preceding claim, configured so that, in the attached configuration, the second portion (12) is secured to the first portion (11) only by said cooperation between the second bearing part (124) and the first bearing part (114).

3. Device (1) according to either one of the preceding claims, wherein the first portion (11) comprises a first attachment member (115) and the second portion (12) comprises a second attachment member (125) complementary to the first attachment member (115), the actuation of one from the first and second attachment members (115, 125) allowing alternate switching between: o a locked configuration in which the first and second attachment members (115, 125) cooperate, preferably by snapping on and / or via a latch mechanism, to lock the device (1) in the attached configuration, and o an unlocked configuration in which the first and second attachment members (115, 125) allow the device (1) to transition from the attached configuration to the detached configuration; preferably, the actuation of one from the first and second attachment members (115, 125) is caused, preferably solely, by the cooperation of the second portion (12) with the first portion (11) to switch from the detached configuration to the attached configuration.

4. Device (1) according to the preceding claim is configured so that actuation of one from the first and second attachment members (115, 125) is performed by manipulating that member by the swimmer so as to switch from the attached configuration to the detached configuration.

5. Device (1) according to any one of the preceding claims, wherein the first portion (11) comprises a first pivot member (111), secured to the first bearing part (114) and the second portion (12) comprises a second pivot member (120), the two pivot members (111, 120) being configured to cooperate, preferably by interlocking, so as to switch from the detached configuration into the attached configuration by tilting of the second bearing part (124) relative to the first bearing part (114).

6. Device (1) according to the preceding claim, wherein the first pivot member (111) and the second pivot member (120) are configured so as to guide the relative movement of the second bearing part (124) relative to the first bearing part (114) when alternately switching from the detached configuration into the attached configuration, according to a rotation about a first axis (X1) substantially perpendicular to a main direction of extension of the tibia Y21.

7. Device (1) according to any one of the preceding two claims, configured such that the amplitude of the tilting rotation of the second portion (12) relative to the first portion (11) is limited by the contact between the second inner face (124a) and the first outer face (114b), preferably the two members (115, 125) are configured to cooperate at the end of the tilting movement, when there is contact between a second inner face (124a) of the second portion (124) and the first outer face (114b) of the first portion (114).

8. The device (1) according to any one of the preceding claims in combination with claim 3, wherein the actuation of one amongst the two attachment members (115, 125) is performed manually without any tool.

9. The device (1) according to any one of the preceding claims in combination with claim 2, wherein, in the attached configuration, the foil (121) is positioned at a distance of at least 10 cm from the first bearing part (114) so as to form in the second portion (12) an opening (122c) enabling passage of the foot (22) of the user (2) through said space (122c).

10. The device (1) according to any one of the preceding claims, wherein, in the attached configuration, the foil (121) extends substantially, in continuation of the direction of the tibia of the user (2).

11. The device (1) according to any one of the preceding claims, wherein the second portion (12) comprises at least one foil support (122) connecting the second bearing part (124) to the foil (121), the foil support (122) being able to elastically deform during use, under the effect of a finning force applied by the user (2).

12. Device (1) according to any one of the preceding claims, comprising a third portion (13) comprising an intermediate member (113) and equipment (13a) configured to at least partially accommodate the foot (22) of the user (2), the intermediate member (113) being rotatably articulated with the first portion (11) about a first axis (X1), and the equipment (13a) being rotatably articulated with the intermediate member (113) about an intermediate axis (X113) that is parallel to and not coincident with the first axis (X1), preferably the second portion (12) is configured so as to create a space (122c) between the second bearing surface (124) and the foil (121), allowing, in the attached configuration, the free movement of the third portion (13) through said space (122c) relative to the second portion (12).

13. Device (1) according to the preceding claim, comprising an additional foil (131) secured to the equipment (13a) and configured to be positioned under the foot of the user (2), the additional foil (131) having a widthwise dimension, along the first axis (X1), substantially with the same dimension as the width of the equipment (13a).

14. Device (1) according to any one of the preceding claims, wherein the second bearing part (124) has a curved surface so as to interlock with the first bearing part (114).

15. Device (1) according to any one of the preceding claims, comprising: - two distinct first portions (11, 11') configured respectively to be secured to each of the legs of the user (2), preferably the two first portions (11, 11') comprise respectively an attachment member (115, 115') configured so as to cooperate each with a complementary attachment member (125, 125') carried by a single second portion (12) configured to cooperate simultaneously with the two first portions (11, 11'), the second portion (12) thus making it possible to secure the two first portions (11, 11') in the attached configuration.