Carrying strap equipped with a shaping reinforcement

Abstract

The invention concerns a carrying strap adjusted, in use, to be installed on the shoulder of a wearer, wherein: - the carrying strap has a shaping reinforcement (3) having an inner surface (Si) and an outer surface (Se), - the reinforcement (3) comprises: - an upper reinforcement portion (30) located, in use, at the shoulder on which the carrying strap is installed, - a front reinforcement portion (31) which extends the upper reinforcement portion (30), - the front reinforcement portion (31) comprises a support portion (32), characterised in that along the upper reinforcement portion (30) and the front reinforcement portion (31), the inner surface (Si) of the reinforcement (3) is shaped as a portion of a Moebius strip, which inner surface, in use, is oriented towards the body of the wearer.

Description

Domaine technique.

[0001] The invention relates to a conforming frame and a carrying strap equipped with this conforming frame. It also relates to load-carrying equipment comprising such a strap. It also relates to a method for manufacturing such a carrying strap.

[0002] It concerns the general technical field of shoulder straps for backpacks or packages carried by the human body. Technique antérieure.

[0003] A load carried in a bag is transmitted to the wearer's back by straps that pass over the wearer's shoulders. If the load is heavy, the weight of the bag is mainly transferred to the hips (if a waist belt is fitted to the bag) and the shoulders of the wearer, who may feel excessive and uncomfortable pressure at this level of the body. In addition, carrying a load leads to postural compensations, and the continuous and regular maintenance of poor posture can lead to musculoskeletal imbalances and pain. Many solutions have been proposed to reduce this uncomfortable distribution of the load on the wearer's shoulders.

[0004] Patent documents EP2371232 (ADIDAS) or FR2781135 (ROSSIGNOL) describe, for example, a bag comprising a pair of shoulder straps. A portion of the upper part of each shoulder strap is made up of an elastic part with limited elongation. This elastic part aims to decouple the backpack from its wearer in order to improve comfort by allowing the wearer to feel less of the generally sudden movements on their shoulders when playing sports or when moving the wearer.

[0005] Patent document EP0570193 (KARRIMOR) describes a shoulder pad for the shoulder strap of a bag, which comprises an elongated element made of synthetic foam comprising one or more sheets of relatively rigid plastic material mounted on its face remote from the wearer's body. The shoulder pad contains several elongated strips of relatively rigid plastic material arranged side by side in the lengthwise direction of the foam element, being separated by gaps. When such a shoulder pad is used on the backpack, the transmission surface is increased, which increases the wearer's comfort and / or the load capacity. Thanks to the elongated strips, the load is spread and the shoulder pads become flexible.

[0006] Patent document EP2606763 (WOOHYUNG) describes a shoulder strap for carrying a bag comprising a portion that can be inflated with air. This air cushion not only reduces the effect of pressure on the wearer's shoulder, but also, by coming into close contact with the shoulder, prevents the bag from slipping or moving laterally.

[0007] Patent document US5961019 (GLEASON) describes a shoulder strap for carrying a bag provided with a pad to cushion and distribute the weight of the bag on the user's shoulders.

[0008] Patent document EP1499212 (COMPAGNIA DEL VIAGGIO) describes a shoulder strap for carrying a bag provided with an additional member to better distribute the weight of the bag on the user's shoulders. This additional member is composed of articulated segments.

[0009] In all of the above-mentioned technical solutions, the shoulder straps mainly press on the shoulders and collarbones of the wearer so that the shoulders and collarbones remain stressed.

[0010] Patent document US2011 / 108595 (HOAG LANCE) describes an exoskeletal structure for a backpack. This structure allows all or part of the load to be transferred to the wearer's hips. However, its design is particularly complex, bulky, and must be relatively expensive.

[0011] Patent document FR3052650 (ERRAFI) describes a bag comprising a right carrying strap and a left carrying strap adapted, in use, to be installed respectively at the right shoulder and the left shoulder of a wearer. A stiffening frame equips each of the carrying straps, this frame having an upper portion curved into a hook which extends downwards by a longitudinal portion. The frame is made of a material having elastic properties, so that said frame deforms elastically with a spring effect when the bag is installed on the shoulders of the wearer. The upper portion curved into a hook is located, in use, at the shoulder on which the carrying strap equipped with the stiffening frame is installed.The longitudinal portion has a segment which is twisted around the longitudinal axis of said longitudinal portion so that, in use, the carrying strap equipped with the stiffening frame is pressed against a region of the wearer's trunk other than the shoulder on which said strap is installed, said strap being pressed against the lateral part of the torso, at the level of the flanks, in the region of the hypochondrium and / or the lateral flanks of the wearer so that all or part of the load of said bag is distributed at the level of this support. The frame described in this patent document forms a load distribution accessory which makes it possible to no longer carry all or part of the weight of the bag on the shoulder and the clavicle of the wearer. The weight of the bag is now shifted, at least in part, towards a support zone which can be stressed more than the shoulders, with an acceptable degree of comfort for the wearer.The bag then feels lighter for the wearer to carry. This frame, although effective, can however cause some discomfort for the wearer due to the conformation of the longitudinal portion.

[0012] Patent document JP3215380U describes a carrying strap that is twisted on itself. This twist is such that the inner surface of the strap that is in contact with the user's shoulder becomes the outer surface after the twist. And vice versa for the outer surface of the strap, which becomes the inner surface in contact with the wearer after the twist. The strap therefore does not have the same inner surface and the same outer surface. This conformation aims to modify the direction of the tension in the strap. However, since the twist is locally located at the user's chest, it must cause particularly uncomfortable discomfort for the wearer.

[0013] One objective of the invention is to remedy this state of affairs. Another objective of the invention is to improve the comfort of the wearer in an efficient and inexpensive manner. An additional objective of the invention is to propose a carrying strap with which the weight of the load is better distributed over the wearer's body. Yet another additional objective of the invention is to propose a solution for shifting all or part of the weight of the bag from the wearer's shoulders, which is simple, compact and inexpensive. Yet another additional objective of the invention is to propose a solution for limiting musculoskeletal disorders induced by carrying a load. Présentation de l'invention.

[0014] The solution proposed by the invention is a conforming frame according to claim 1.

[0015] With this particular conformation of the frame, which can be similar to a portion of a Moebius strip, the inventor observed increased comfort when carrying a load and better transfer of the load towards the wearer's support surface, compared to a conventional bag not equipped with a carrying strap according to the invention. The inventor was able to observe that the load was in fact shifted towards the wearer's center of gravity. Carrying is thus more comfortable and more efficient. The inventor also observed that with a bag equipped with such straps, the wearer was able to walk longer distances, experiencing less fatigue. The wearer's posture and walking kinematics are significantly less altered than with one of the conventional straps, so that said strap has real added value in terms of ergonomics and reduction of musculoskeletal disorders.The conforming frame, whose shape allows these advantages to be provided to the carrying strap, is simple to manufacture, so that the proposed solution is inexpensive to implement.

[0016] Other advantageous features of the invention are listed below. Each of these features may be considered alone or in combination with the features defined above with regard to the technical problems that they specifically solve, and may be the subject, where appropriate, of one or more divisional patent applications: According to one embodiment: the upper frame portion has a first free end; - the front frame portion has a second free end; - the inner surface of the frame has the shape of a Moebius strip portion from the first free end to the second free end such that said inner surface is twisted not only along the entire front frame portion, but also along the entire upper frame portion. According to one embodiment, the outer surface of the frame has the same shape as the inner surface of said frame. According to one embodiment, the following characteristics also geometrically define the shape of the inner surface of the frame: the angular speed of rotation of the segment, when its middle moves along the trajectory, is uniform and non-zero along the trajectory.According to one embodiment, the angular speed of rotation of the segment, when its middle moves along the trajectory, is variable and non-zero along said trajectory. According to one embodiment, the length of the segment is constant along the trajectory. According to one embodiment, the length of the segment varies along the trajectory. According to one embodiment, the front frame portion has a free end having a flared shape. According to one embodiment, the upper frame portion has a free end curved upwards.According to one embodiment: - a rear frame portion also extends the upper frame portion, which rear frame portion is adapted to extend, in use, towards the bottom of the wearer's trunk, from the dorsal face of said wearer; - the rear frame portion comprises a support portion shaped so that, in use, the carrying strap comes to bear against a rear support surface of the wearer located in a dorsal region of the wearer or at a lateral flank of said wearer.

[0017] Another aspect of the invention relates to a load carrying strap adapted, in use, to be installed at the level of a wearer's shoulder, which carrying strap is equipped with a conforming frame. Yet another aspect of the invention relates to equipment for carrying a load on the human body, comprising a left carrying strap and a right carrying strap, each of said straps conforming to one of the preceding characteristics.

[0018] Yet another aspect of the invention relates to equipment for carrying a load on the human body, comprising a single carrying strap, said strap conforming to one of the preceding characteristics.

[0019] An additional aspect of the invention relates to a method for manufacturing a carrying strap conforming to one of the preceding characteristics, comprising the steps of: - shaping the conforming frame so that the front frame portion extends towards the bottom of the trunk of a wearer, from the ventral face of said wearer and that the support portion is located on a front face or on a lateral face of the thorax or abdomen of said wearer; - equipping the carrying strap with the conforming frame. Brève description des figures.

[0020] Other advantages and characteristics of the invention will appear more clearly on reading the description of a preferred embodiment which follows, with reference to the appended drawings, produced as indicative and non-limiting examples and in which: [ Fig. 1 ] a view of a bag according to the invention, the bag being carried by an individual seen from the front, [ Fig. 2a ] is a right profile view of a frame of a carrying strap according to the invention, [ Fig. 2b ] is a left profile view of the frame of the figure 2a , [ Fig. 2c ] is a front view of the frame of the figures 2a And 2b , [ Fig. 3 ] represents cross sections of a frame of a carrying strap according to the invention, according to different embodiment variants, [ Fig. 4 ] is a perspective view of a portion of the carrying strap according to one embodiment of the invention, cut transversely, [ Fig. 5 ] is a perspective view of a portion of the carrying strap according to another embodiment of the invention, cut transversely, [ Fig. 6 ] is a perspective view of a portion of the carrying strap according to another embodiment of the invention, cut transversely, [ Fig. 7 ] represents a backpack carried by an individual seen in profile, comprising carrying straps according to the invention, [ Fig. 8 ] illustrates a manner, not forming part of the invention, in which the internal surface of the frame is generated. [ Fig. 9 ] represents trajectories of the middle of a segment generating the internal surface of the reinforcement, according to different variant embodiments not forming part of the invention, [ Fig. 10 ] represents other trajectories of the middle of a segment generating the internal surface of the reinforcement, according to different embodiment variants, [ Fig. 11 ] is a front perspective view of a frame of a carrying strap according to the invention, in an alternative embodiment [ Fig. 12 ] is a rear perspective view of a frame of a carrying strap according to the invention, in another variant embodiment Description des modes de réalisation,

[0021] The invention relates to a conforming frame for equipping a carrying strap particularly suitable for equipping equipment for carrying a load on the human body. By "load-carrying equipment" is meant any type of accessory provided with one or more carrying straps and which is worn by the human body. It may be a travel bag, a sports bag, a golf bag, a hiking bag, a military or firefighter bag, a school bag, a baby carrier, a protective vest (bullet-proof vest, bomb disposal suit), etc. In general, this bag is intended to carry a load: clothing, notebooks, equipment including military equipment, oxygen cylinder, fire hose, books, sports accessories, baby, etc.

[0022] There figure 1 represents a piece of equipment 1 of the backpack type. This bag 1 is of a conventional design. It includes in particular an internal cavity for receiving the load to be carried. It has a rear face which, in use (i.e. when the bag 1 is worn), is in contact with the back of the wearer 2.

[0023] To improve carrying comfort and reduce the feeling of the weight of the load being carried, the lower end of the rear face of the bag 1 may optionally be extended on each side by a two-part abdominal or ventral belt 6, 7, which allows the lower part of the bag 1 to be fixed around the wearer's waist. A fastening loop allows the two parts 6, 7 of this belt to be secured together. The latter is well known to those skilled in the art.

[0024] On the figure 1 , the bag 1 comprises a pair of carrying straps, respectively a right strap 8a and a left strap 8b which are similar. The bag 1 may however have only one carrying strap, in which case said bag is called a single-strap bag. In use, and as illustrated in the figure 1 , the right strap 8a passes over the right shoulder 12 of the wearer 2 and the left strap 8b passes over his left shoulder 15. The right strap 8a, respectively left 8b, runs from top to bottom along the front face of the thorax 13 (and possibly the abdomen 14, depending on the length of the strap), then crosses the right lateral face 16, respectively left 17, of the thorax 13 (or possibly the abdomen 14) of the individual 2, until reaching the right side, respectively the left side of the lower part of the dorsal face of the bag 1. The straps 8a, 8b are generally flat. Their width is for example between 10 mm and 100 mm.

[0025] Each carrying strap 8a, 8b here has an adjustment strap allowing the length of the carrying strap 8 to be adjusted. The backpack 1 of the figure 1 further comprises a chest strap comprising a right strap portion 9, which extends from the right carrying strap 8a, and a left strap portion 10, which extends from the left carrying strap 8b. This chest strap allows better adjustment of the position of the bag 1 and the position of the shoulder straps 8a, 8b according to the anatomy and morphology of the wearer 2. An upper end of each carrying strap 8a, 8b is fixed (for example by sewing) to the upper part of the dorsal face of the bag 1. The adjustment strap is also fixed (for example by sewing) to the lower part of the dorsal face of the bag 1.

[0026] Without the stiffening reinforcements described further in the description, the straps 8a and 8b are flexible, that is to say easily deformable, manually. These reinforcements make it possible to conform the straps, and stiffen them. Also, the straps 11a and 11b are more rigid - or less flexible - with the reinforcements than without these reinforcements, and / or said reinforcements imprint their shape on said straps.

[0027] A 3 frame is shown on the figures 2a And 2b . To simplify the design, the frame equipping the right shoulder strap 8a is identical to the frame equipping the left shoulder strap 8b. The right and left frames may however be distinct depending on the shoulder strap it equips and / or depending on the type of bag to be equipped and / or depending on the anatomy and / or morphology of the wearer 2.

[0028] According to one embodiment, the reinforcements 3 are thin, that is to say that their cross-section has a width "l" which is greater than their thickness "e" ( figure 3 ). For example, the width "l" is between 5 mm and 80 mm and the thickness "e" is between 0.5 mm and 20 mm. The thin nature of the frames 3 gives them lightness, flexibility and elasticity. The unrolled length of the frame 2 (length between the ends 300-310) is for example between 100 mm and 1 m. This length depends on the anatomy and / or the morphology of the wearer, the latter being able to be a schoolchild, a teenager, an adult, and a man or a woman. Of course, this length also depends on the size of the strap 8a, 8b which is itself adapted to the size of the bag 1, but also on the morphology of the individual 2.

[0029] On the figures 2a And 2b, the frame 3 is in the form of a flat blade, with a rectangular cross-section 23. Referring to the figure 3 , the frame 3 may however have another cross-section, in particular a plano-convex section 26, the flat surface extending towards the inside of the bag 1, that is to say as close as possible to the front face of the thorax 13 and / or the abdomen 14 of the individual 2 when the latter is wearing said bag, the convex surface extending towards the outside of said bag; a concave or curved section 27 slightly curved so as to better fit the morphology of the wearer 2; an oval or convex-convex section 29; a section having longitudinal ribs 43 so that said section has teeth 45 making it possible to stiffen said frame. A square cross-section may also be envisaged, the frame 3 in this case not being considered thin.

[0030] The frame 3 has elastic properties allowing it to deform elastically, reversibly. This elasticity allows the frames 3 to best follow the curvature of the straps 8a, 8b as well as that of the wearer's torso 2, with a spring effect, as explained in detail further on in the description.

[0031] The frames 3 can be obtained by molding or machining. They are for example made of: - plastic such as PVC or a urethane polymer (polyurethane); - metal such as stainless steel, aluminum alloy, copper alloy, brass alloy; - composite material such as glass fibers or carbon fibers mixed with a thermoplastic or thermosetting resin; raw wood, laminated wood, glued laminated wood; - etc. Any other material suitable to a person skilled in the art can be used. The frame 3 can also be formed of several materials, comprising for example a core made of a metallic material, which core is coated with silicone or another flexible plastic material ensuring electrical insulation in addition to increased comfort.

[0032] On the figures 2a , 2b And 2c, the frame 3 has an internal surface - or wall - Si and an external surface - or wall Se. The internal surface Si is the surface of the frame 3 which, in use, is oriented towards the body of the wearer 2. The external surface Se is the other surface of the frame 3 which is opposite the internal surface Si. It is the same internal surface Si which is oriented towards the body of the wearer 2, all along the frame 3, unlike the aforementioned document JP3215380U. Indeed, in this document JP3215380U, after the twisting of the strap, the internal surface becomes the external surface and the external surface becomes the internal surface.

[0033] The frame 3 has an upper portion 30 which is located, in use, at the shoulder 12, 15 on which the carrying strap 8a, 8b equipped with the respective frame 3 is installed. This upper portion 30 is preferably curved in the shape of an arc or hook and the curvature of which is adapted to the morphology of the shoulders 12, 15 of the wearer 2. Thus, when the wearer 2 carries the bag 1, the carrying strap 8a, 8b extends above his shoulder 12, 15. The upper portion 30 has a free end 300 (or upper free end).

[0034] This upper portion 30 extends downwards by a front frame portion 31. These two portions 30, 31 here form a single and same piece, without discontinuity. All or part of the front frame portion 31 is installed in the carrying strap 8a, 8b. It extends, in use, towards the bottom of the trunk of the wearer 2, from the ventral face of said wearer whatever the anatomy and / or morphology of said wearer. On the figure 1 , the front frame portion 21 extends along the length of the carrying strap 8a, 8b, up to the lower end 80a, 80b of said strap. In one embodiment, the lower end 310 of the front frame portion 31 (i.e. its lower free end) does not reach the lower end 80a, 80b of the strap 8a, 8b, the length of the frame 3 being shorter than the length of said strap. In another embodiment, the lower end 310 of the front frame portion 31 is not housed in the strap 8a, 8b, but is located outside of the latter. In the latter case, an opening is provided in the strap 8a, 8b allowing the front frame portion 31 to be removed from said strap.

[0035] When a frame 3 is associated with a strap 8a, 8b, the latter takes the shape of said frame. The frame 3 therefore makes it possible to shape the strap 8a, 8b. This property is used, within the framework of the invention, to create new support points or zones for said strap in a region of the wearer's trunk 2 other than the shoulders 12, 15.

[0036] On the figures 2a And 2b , the front frame portion 31 comprises a support portion 32 shaped so that, in use, the strap 8a, 8b comes to bear against a support surface 24 of the wearer 2 (visible on the figure 1 ). The support portion 32 is located on the internal surface Si of the frame 3 and comes to bear, flat, directly or via a protective layer of the strap 8a, 8b, against the support surface 24. The frame 3 is shaped so that the support surface 24 is located on the front face of the thorax 13 or the abdomen 14 of the wearer 2. The shape of the frame 3 can therefore be adjusted, at the time of its manufacture, to take into account the anatomy and / or the morphology of the wearer 2. On the figure 1 , the support surface 24 is located at the level of the pectorals of the individual 2, this position giving very good results in terms of comfort of the wearer 2 and reduction of the feeling of the weight of the load carried. It is also possible to provide for conforming the frame 3 so that the support portion 32 acts on a support zone 24 located on a lateral face 16, 17 of the thorax 13 or the abdomen 14.

[0037] In the embodiment of the figures 2a And 2b, the internal surface Si of the armature 3 is geometrically generated by the non-zero rotation and in the same direction, of a segment around its middle (which is the center of rotation of the segment), which middle follows a trajectory describing a curve. The internal surface Si thus has the shape of a portion of a Moebius strip.

[0038] There figure 8 illustrates, from a geometric point of view, how the internal surface Si is generated. The length of the segment AB corresponds to the width of the internal surface Si (and of the reinforcement 3). The middle of the segment AB is noted M. The trajectory of the middle M is noted T and describes a curve. The trajectory T defines the longitudinal axis of the reinforcement 3. The trajectory T is delimited by the point T0 (which corresponds to the upper free end 300 of the reinforcement 3) and the point T1 (which corresponds to the lower free end 310 of the reinforcement 3). The segment AB is here a straight line segment, but can be a curved segment, in particular to obtain a non-flat internal surface (concave, convex, etc.) as illustrated in the variants of the figure 3 .

[0039] The trajectory T of the figure 8 describes a 2-dimensional curve - 2D curve or plane curve - contained in the xOy plane of the orthonormal reference frame (O, Ox, Oy, Oz). Referring to the figure 9 , the trajectory can describe a portion of a circle Ta, a portion of an ellipse Tb, a portion of a logarithmic curve Te, a portion of a hyperbola Td, a portion of an arch of a cycloid curve Te, or any other curve approaching these without strictly respecting their mathematical equation. This type of curve makes it possible to obtain very good results in terms of comfort and reduction of the feeling of the weight of the load carried.

[0040] The trajectory T is a curve drawn in a 3-dimensional space - 3D curve or left curve - contained in the space (O, x, y, z). Referring to the figure 10 , the trajectory describes a portion of helix Tf, a portion of rational sextic Tg, a portion of non-rational sextic Th. This type of curve also makes it possible to obtain excellent results in terms of comfort and reduction of the feeling of the weight of the load carried.

[0041] On the figure 8 , the middle M moves on the trajectory T, between the point To and the point T1. Between these two points T0 and T1, the segment AB pivots continuously around its middle M. This rotation is non-zero and in the same direction along said trajectory T. The internal surface Si is thus twisted - or undergoes a torsion movement - not only along the entire front reinforcement portion 31, but also along the entire upper reinforcement portion 30. The reinforcement 3 therefore has no straight portion. On the figure 8 , the angle that the segment AB makes with the horizontal direction (plane xOy) is noted "αi". For example, at point T0 of trajectory T, α0 = 90°, and at point T1 α1 = 45°. Between points T0 and T1, the angle αi can describe an angular sector of 90°, advantageously 45°, preferably 60°.

[0042] During its movement between points T0 and T1, and geometrically speaking, the rotational speed of segment AB is not zero and can be constant (uniform or equal angular rotational speed along trajectory T) or inconstant (variable or different angular rotational speed along trajectory T). The choice of this rotational speed makes it possible to adapt as best as possible to the morphology of the wearer 2 and / or to adjust very precisely the location of the support portion 32. For the same reasons, the length of segment AB (which corresponds to the width of the frame 3) can be constant or vary along trajectory T, between points T0 and T1. For example, as illustrated in the figure 11 , the lower free end 310 of the frame 3 may have a flared shape, in the form of a goose foot or a spatula. This flared shape makes it possible to further maximize the surface area of ​​the support portion 32 at the level of the support zone 24. The same flared shape may be provided at the level of the upper free end 300.

[0043] In the embodiment of the figure 11 , the upper free end 300 of the upper frame portion 30 is curved upwards. In this configuration, the upper end of the strap 8a, 8b is raised upwards, which prevents it from pressing on the trapezius muscles of the wearer 2. The comfort of the wearer 2 is therefore increased.

[0044] On the figures 2a And 2b, the external surface Se of the frame 3 has the same shape as the internal surface Si, which makes it possible to simplify the design of said frame. Since the external surface Se is not intended to come directly into contact with the body of the wearer 2, it can be considered that it is not the same shape as the internal surface Si.

[0045] The shape of the frame 3 makes it possible to very precisely orient the support portion 32 parallel to the support zone 24 of the wearer 2. The frame 3 will impart a twisting movement to the strap 8a, 8b so that the latter follows the curvature of the trunk of the wearer 2 as best as possible and at the same time the support portion 32 reaches a target support zone 24. This support zone 24 may vary according to the type of bag or load-carrying equipment and / or according to the morphology, size, type and / or sex of the wearer 2. In addition, the specific shape of the internal surface Si of the frame 3 (and more generally the specific shape of said frame), makes it possible to shift the straps 8a, 8b forward and / or upward from the clavicles and / or shoulders 12, 15 of the wearer 2. As this appears on the figure 7 , it is advantageously provided that the curvature of the upper frame portion 30 is greater than that of the shoulders 12, 15 so that said portion is not, or only slightly, in support against said shoulders and / or the clavicles and / or the trapezius muscles. The elimination of these supports reduces the static postural compensations of the wearer and therefore the muscular activity necessary for this support. In addition, the release of the shoulders allows a more physiological swing of the arms during walking. This results in better stability (in particular: limitation of the flexion of the wearer's trunk forward, limitation of the rolling of the shoulders, limitation of the flexion of the head and its projection forward).This lesser alteration of posture is accompanied by a decrease in the muscular activity of the wearer's trunk, a greater amplitude of rotation of the pelvis, a decrease in the amplitude of flexion / extension of the hips and ankles, an increase in the amplitude of flexion / extension of the knees, a decrease in the frequency of the stride and an increase in its length.

[0046] In traditional bags, the shoulder straps 8a, 8b pass over the shoulders 12, 15 and the collarbones of the wearer 2, descend against the pectorals and then pass under the armpits. The shoulders 12, 15 are therefore the main support zones of the shoulder straps 8a, 8b, the majority of the weight of the load being taken up at the level of said shoulders. The shape of the frame 3 makes it possible to orient the support portion 32 very precisely, towards a targeted support zone 24, and parallel to the latter. The best results, in terms of comfort and reduction in the feeling of the weight of the load carried, are obtained when the support zone 24 is located at the level of the pectorals of the wearer 2, preferably in the upper or lateral part of said pectorals.

[0047] The fact of forcing the shoulder strap 8a, 8b to come and press against the support zone 24, means that said shoulder strap does not rest directly on a shoulder 12, 15, nor on a clavicle nor on a trapezius of the wearer 2. On the contrary, each shoulder strap 8a, 8b comes to bear against the support surface 24 of the wearer 2, so as to apply against said support surface at least a part (or even all) of the load of the bag 1 and of the object(s) transported therein. The load is therefore shifted onto the support surface 24 which can be stressed more than the shoulders 12, 15 without this generating discomfort. The backpack 1 appears much lighter. It has been observed that, when a bag 1 comprising carrying straps 8a, 8b according to the invention is used, the load to be carried can be increased by 10% to 80% without significant perception for the wearer 2. In other words, for the same load, the backpack 1 appears much lighter for the individual carrying it.

[0048] More precisely, and as illustrated on the figure 7 , the shoulder straps 8 equipped with the frames 3, make it possible to enclose the trunk of the wearer 2 at the level of two support zones: the first support zone located on a front face or on a lateral face of the thorax 13 or the abdomen 14 of said wearer (support surface 24), and a second support zone 25 located in the back of the wearer 2 (contact zones(s) between the bag 1 and the back). When the wearer 2 installs the bag 1 on his shoulders 12, 15, the frames 3 act like jaws by deforming elastically, with a spring effect, to grip, without injuring him, the trunk of the wearer 2. All or part of the weight of the load is then shifted and distributed at the level of these two support zones 24, 25, relieving the shoulders 12, 15 and / or the clavicles and / or the trapezius muscles of the wearer 2, of all or part of the weight that they initially supported without the use of the shoulder straps 8 equipped with the frames 3.The deformation of the frames 3 is induced by the weight of the bag 1 when it is carried by the carrier 2. In other words, it is mainly when the bag 1 is carried by the carrier 2 that the frames 3 deform to put themselves in place and press at the level of the support zone 24.

[0049] In the present description, when it is indicated that the carrying strap 8a, 8b extends or comes to bear "against" the trunk of the wearer 2 (bearing surface 24), this of course means against the trunk or against a garment covering the trunk. Similarly, when it is indicated that the carrying strap 8a, 8b does not rest on a shoulder 12, 15, this means that it could be in contact, at the shoulder, with a garment of the wearer 2.

[0050] Different techniques for securing the frames 3 to the straps 8a, 8b will now be explained in detail, with reference to figures 4 à 6 .

[0051] In the embodiment of the figure 4 , the shoulder strap 8 comprises a protective layer 80 comprising a padded or padding layer 81, for example a layer of elastomer foam, covered by an external layer 82 made for example of fabric, plastic, leather, etc. The carrying strap 8 here has a substantially rectangular section. Inside the protective layer 80 is defined a cavity 83 which extends along the length of the shoulder strap 8. The cavity 83 has a substantially rectangular section (and is therefore intended to accommodate a frame 3 of rectangular section). The cavity 83 and the protective layer 80 form a sheath having an opening positioned near an upper end or a lower end of the strap 8. The frame 3 is removably inserted into this sheath, at the level of an opening (or slot) provided in the strap 8 and opening on the one hand at the level of the protective layer 80 and on the other hand into the cavity 83.The frame 3 can thus be inserted into or removed from the shoulder strap 8. When the frame 3 is removed, the shoulder strap 8 becomes a conventional shoulder strap again and, if the frames 3 of the two shoulder straps 8a, 8b are removed, the bag 1 becomes a conventional backpack again. The dimensions of the rectangular section of the cavity 33 are preferably slightly larger than those of the rectangular section of the frame 3 to facilitate the insertion or removal thereof.

[0052] In reference to the figure 5 , the frame 3 is arranged not inside, but on the protective layer 80. The frame 3 is fixed on the protective layer 80 by loops 87 distributed along the length of the strap 8 and which are for example sewn or welded on said strap, on either side of the frame 3. Stop pieces 88 are formed on the strap 8 to accommodate and hold in position each end of the frame 3. It is noted that the frame 3 could be fixed by different fixing means: loops, loop bands, hooks of the type Velcro ®< , etc. The frame 3 here covers the strap 8. It covers more particularly the external layer 82, and is placed on the external face of the strap 8, that is to say the face which is not in contact with the body of the wearer 2. It is however possible to envisage the frame 3 being placed on the internal face of the strap 8, that is to say the face which is in contact with the body of the wearer 2.

[0053] On the figure 6, the strap 8 has a plano-convex section. The strap 8 comprises a protective layer 80 whose external shape also has a plano-convex section. Inside the protective layer 81 is defined a cavity of rectangular section which extends along the length of the strap 8. The cavity and the protective layer 80 again form a sheath having an opening positioned near an upper end or a lower end of the strap 8. The frame 3 has a rectangular section. The frame 3 is positioned inside the sheath, in a removable manner or not. The frame 3 can be glued to the protective layer 80. The protective layer 80 can also have been molded onto the frame 3 at the time of manufacture of the strap 8, said frame forming the core of said strap. The thickness of the protective layer 80 between the flat surface of said layer and the reinforcement 3 is very small.

[0054] In an alternative embodiment, the upper frame portion 30 may be extended by a rear frame portion, which rear frame portion extends, in use, towards the bottom of the trunk of the wearer 2, from the dorsal face of said wearer. The frame 3 in this case has a hoop or horseshoe shape, comprising a front branch (front frame portion 31), a rear branch (rear frame portion) and an upper portion 30. The upper portion 30 includes an upper part of the front branch and an upper part of the rear branch. The front and rear branches may be of the same length or of different lengths.

[0055] As for the front frame portion 31, this rear frame portion comprises a rear support portion shaped so that, in use, the carrying strap 8a, 8b, (or directly said rear frame portion) comes to bear against a rear support surface of the wearer 2 located in a dorsal region of the wearer (back, lumbar) or at the level of a lateral flank of said wearer. The frame 3 thus has two distinct support portions.

[0056] Along the rear reinforcement portion, the inner surface Si of the reinforcement 3 (and possibly its outer surface Se) can also be generated by the continuous rotation of a segment around its center, which center has a trajectory T describing a curve. The rear reinforcement portion is then twisted. Preferably, the front and rear reinforcement portions are not twisted in the same direction, so as to optimize the supports at the front support surface and the rear support surface. The rear reinforcement portion may also not be twisted.

[0057] Such a two-branch frame 3 makes it possible to grip the trunk of the wearer 2 at two support zones: a first ventral region where the front frame portion rests and a second dorsal region where the rear frame portion rests. These two support zones are located on the same side of the trunk (to the right or left of the sagittal plane of the wearer 2). When the wearer 2 installs the bag 1 on his shoulders, the front frame portion and the rear frame portion of each frame move apart at the trunk of the wearer 2 and act like jaws by deforming elastically, with a spring effect, to grip said trunk without injuring him.

[0058] When each of the straps 8a, 8b is equipped with a two-pronged frame 3, a double pinching effect is obtained: the frame 3 cooperating with the right strap 8a acts as a clamp in the right part of the trunk and the frame 3 cooperating with the left strap 8b acts as a clamp in the left part of said trunk. All or part of the weight of the load is then shifted and distributed at the level of these two new support zones.

[0059] A pinch effect (right, left or diagonal to the trunk) can also be achieved with a single two-pronged 3-frame, making it possible to equip a single-strap bag.

[0060] The arrangement of the various elements and / or means and / or steps of the invention, in the embodiments described above, should not be understood as requiring such an arrangement in all implementations. In any event, it will be understood that various modifications may be made to these elements and / or means and / or steps, without departing from the invention as defined in the appended claims.

[0061] One or more features disclosed only in one embodiment may be combined with one or more other features disclosed only in another embodiment. Similarly, one or more features disclosed only in one embodiment may be generalized to other embodiments, even if that or those features are described only in combination with other features.

Claims

1. A shaping frame (3) designed to equip a shoulder strap (8a, 8b) of a load, the shoulder strap (8a, 8b) being adapted, in use, to being installed at the level of a shoulder (12, 15) and a support surface (24) of a wearer (2), the shaping frame (3) having one same inner surface (Si) and one same outer surface (Se) and comprising: -- an upper frame portion (30) located, in use, at the level of the shoulder (12, 15), when the shoulder strap (8a, 8b) equipped with the shaping frame (3) is installed on the shoulder (12, 15) of the wearer (2), -- a front frame portion (31) which extends the upper frame portion (30), which front frame portion extends downwards, the front frame portion (31) comprising a support portion (32) shaped such that, in use, the support portion bears against a support surface (24) of the wearer (2) when the shoulder strap (8a, 8b) equipped with the shaping frame (3) bears against the support surface (24) of the wearer (2), the upper frame portion (30) and the front frame portion (31), the inner surface (Si) of the shaping frame (3) having the shape of a Moebius strip portion, which inner surface (Si) is, in use, oriented towards the support surface (24) of the wearer the shaping frame (3) being characterized in that the shape of the inner surface (Si) of the shaping frame (3) is geometrically defined by the following features: - the inner surface (Si) is caused by a continuous rotation of a segment (AB) about its middle (M), the length of said segment corresponds to the width of said inner surface, and - the middle (M) of said segment describes a trajectory (T) describing a curve, and - the continuous rotation is non-zero and in the same direction, along said trajectory (T), - the curve described by the trajectory (T) being a left curve selected from a helix portion (Tf), or a rational sextic portion (Tg), or a non-rational sextic portion (Th).

2. Shaping frame (3) according to claim 1, wherein: - the upper frame portion (30) has a first free end (300), - the front frame portion (31) has a second free end (300), - the inner surface (Si) of the frame (3) has the shape of a Moebius strip portion from the first free end (300) to the second free end (310), such that said inner surface is twisted not only along the whole front frame portion (31), but also along the whole upper frame portion (30).

3. Shaping frame (3) according to one of claims 1 or 2, wherein the shape of the inner surface (Si) of the frame (3) is geometrically defined by the following characteristics: - the angular rotation speed of the segment (AB), when its middle (M) is moved along the trajectory (T), is uniform and non-zero along said trajectory, or - the angular rotation speed of the segment (AB) is variable and non-zero along said trajectory.

4. Shaping frame (3) according to one of claims 1 to 3, wherein the length of the segment (AB) is constant or variable along the trajectory (T).

5. Shaping frame (3) according to claim 4, wherein the front frame portion (31) has a free end (310) having a flared shape.

6. Shaping frame (3) according to one of the preceding claims, wherein the upper frame portion (30) has a free end (300) curved upwards.

7. Shaping frame (3) according to one of the preceding claims, wherein: - a rear frame portion also extends the upper frame portion (30), which rear frame portion is adapted to extend, in use, downwards from the torso of the wearer, from the back face of said wearer, - the rear frame portion comprises a support portion shaped such that, in use, the rear frame portion bears against a rear support surface of the wearer (2) located in a back region of the wearer or at the level of a lateral flank of said wearer (2), when the shoulder strap (8a, 8b) equipped with the shaping frame (3) bears against said rear support surface of the wearer (2).

8. Shaping frame (3) according to claim 1, wherein the outer surface (Se) of the shaping frame (3) has the same shape as the inner surface (Si) of said shaping frame.

9. Shoulder strap (8a, 8b) adapted, in use, to being installed at the level of a shoulder (12, 15) of a wearer (2), the shoulder strap (8a, 8b) being equipped with a shaping frame (3) according to one of claims 1 to 8.

10. Load-removing equipment on the human body, comprising a left shoulder strap (8b) and a right shoulder strap (8a), characterized in that each of said shoulder straps is in accordance with claim 9.

11. Method for manufacturing a shoulder strap according to claim 9, comprising steps consisting of: - shaping the shaping frame (3) such that the front frame portion (31) extends downwards from the torso of a wearer (2), from the stomach face of said carrier and that the support portion (32) is located on a front face or on a lateral face of the thorax (13) or of the abdomen (14) of said carrier, - equipping the shoulder strap (8a, 8b) of the shaping frame (3).

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