SHOULDER STRAP EQUIPPED WITH A SHAPING FRAME
A carrying strap adjusted, in use, to be installed on the shoulder of a wearer, where the carrying strap has a shaping reinforcement having an inner surface and an outer surface, the reinforcement includes: an upper reinforcement portion located, in use, at the shoulder on which the carrying strap is installed, a front reinforcement portion which extends the upper reinforcement portion, the front reinforcement portion includes a support portion, where, along the upper reinforcement portion and the front reinforcement portion, the inner surface of the reinforcement is shaped as a portion of a Moebius strip, which inner surface, in use, is oriented towards the body of the wearer.
The invention aims for a shoulder strap equipped with a shaping frame. It also aims for a bag and load removing equipment comprising such a strap. It also aims for a method for manufacturing such a shoulder strap.
It relates to the general technical field of straps for backpacks or packages carried by the human body.
PRIOR ARTA load transported in a bag is transmitted on the back of the carrier by straps which go over the shoulders of said carrier. If the load is significant, the weight of the bag is mainly transferred to the level of the hips (in the case where a waist belt equips the bag) and to the level of the shoulders of the carrier, who can feel an excessive and uncomfortable pressure at this level of the body. Furthermore, carrying a load leads to postural compensations, and the continuous and regular maintaining of a bad posture can lead to musculoskeletal imbalances and pain. Numerous solutions have been proposed to reduce this uncomfortable distribution of the load on the shoulders of the carrier.
Patent documents EP2371232 (ADIDAS) or FR2781135 (ROSSIGNOL) describe, for example, a bag comprising a pair of straps. A portion of the upper part of each strap is constituted by an elastic part which is limited in extension. This elastic part aims to uncouple the backpack from its carrier to, on the one hand, improve comfort by allowing the carrier to feel movements less on their shoulders, generally sudden, when playing sport or while said carrier is moving.
Patent document EP0570193 (KARRIMOR) describes a shoulder-piece for the strap of a bag, which comprises an extended element made of synthetic foam comprising one or more sheets made of relatively rigid plastic material mounted on its face extended from the body of the carrier. The shoulder-piece contains several extended strips made of relatively rigid plastic material disposed side-by-side in the direction of the length of the foam element, by being separated by spacings. When such a shoulder-piece is used on the backpack, the transmission surface is increased, which increases the comfort of the carrier and/or the load capacity. Thanks to the extended strips, the load is spread and the shoulder-pieces become flexible.
Patent document EP2606763 (WOOHYUNG) describes a shoulder strap of a bag comprising a part which could be filled with air. This air cushion not only allows to reduce the effect of pressure on the shoulder of the carrier, but also, by coming into close contact with the shoulder, to prevent the bag from sliding or from moving laterally.
Patent document U.S. Pat. No. 5,961,019 (GLEASON) describes a shoulder strap of a bag provided with a pad allowing to dampen and to distribute the weight of the bag over the shoulders of the user.
Patent document EP1499212 (COMPAGNIA DEL VIAGGIO) describes a shoulder strap of a bag provided with an additional member to better distribute the weight of the bag over the shoulders of the user. This additional member is composed of articulated segments.
In all the above-mentioned technical solutions, the straps mainly press on the shoulders and the collarbones of the carrier such that the shoulders and the collarbones remain urged.
Patent document US2011/108595 (HOAG LANCE) describes an exo-skeletal structure for a backpack. This structure allows to extend all or some of the load to the hips of the carrier. Its design is however particularly complex, cumbersome and must be relatively expensive.
Patent document FR3052650 (ERRAFI) describes a bag comprising an adapted right shoulder strap and an adapted left shoulder strap, in use, to be installed respectively at the level of the right shoulder and of the left shoulder of a carrier. A rigidifying frame equips each of the shoulder straps, this frame having a hook-shaped curved upper portion which extends downwards through a longitudinal portion. The frame is made of a material having elastic properties, such that said frame is elastically deformed with a spring effect when the bag is installed on the shoulders of the carrier. The hook-shaped curved upper portion is located, in use, at the level of the shoulder on which is installed the shoulder strap equipped with the rigidifying frame. The longitudinal portion has a segment which is twisted about the longitudinal axis of said longitudinal portion such that, in use, the shoulder strap equipped with the rigidifying frame is flattened against a region of the torso of the carrier other than the shoulder on which said strap is installed, said strap being flattened 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 carrier such that all or some 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 allows to no longer carry all or some of the weight of the bag on the shoulder and the collarbone of the carrier. The weight of the bag is now moved, at least partially, to a support zone which can be further urged than the shoulders, with an acceptable degree of comfort for the carrier. The bag thus seems lighter to carry for the carrier.
This frame, although effective, can however lead to a certain impediment for the carrier, due to the shaping of the longitudinal portion.
Patent document JP3215380U describes a shoulder strap which is twisted on itself. This twisting is such that the inner surface of the strap which is in contact with the shoulder of the user becomes the outer surface after twisting. And conversely, for the outer surface of the strap which becomes the inner surface in contact with the carrier after twisting. The strap therefore does not have one same inner surface and one same outer surface. This shaping aims to modify the direction of the tension in the strap. However, with the twisting being locally located at the level of the chest of the user, it must provide a particularly uncomfortable impediment for the carrier.
An aim of the invention is to overcome this state of affairs.
Another aim of the invention is to improve the comfort of the carrier effectively and inexpensively.
An additional aim of the invention is to propose a shoulder strap with which the weight of the load is better distributed over the body of the carrier.
Also, another additional aim of the invention is to propose a solution for moving all or some of the weight of the bag from the shoulders of the carrier, which is simple, of reduced bulk and inexpensive.
Also, another additional aim of the invention is to propose a solution allowing to limit the musculoskeletal issues induced by carrying a load.
PRESENTATION OF THE INVENTIONThe solution proposed by the invention is a shoulder strap adapted, in use, to being installed at the level of a shoulder of a carrier, wherein:
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- the shoulder strap comprises a shaping frame having one same inner surface and one same outer surface,
- the frame comprises:
- an upper frame portion located, in use, at the level of the shoulder on which the shoulder strap is installed,
- a front frame portion which extends the upper frame portion, which front frame portion extends downwards,
- the front frame portion comprises a support portion shaped such that, in use, the shoulder strap bears against a support surface of the carrier,
- along the upper frame portion and the front frame portion, the inner surface of the frame has the shape of a Moebius strip portion, which inner surface is, in use, oriented towards the body of the carrier.
With this particular shaping of the frame, which can be similar to a Moebius strip portion, the inventor has observed an increased comfort during the carrying of a load and a better extension of the load towards the support surface of the carrier, compared with a conventional bag not equipped with any shoulder strap according to the invention. The inventor has been able to observe that the load was, in reality, moved towards the center of gravity of the carrier. The carrying is thus more comfortable and more effective. The inventor has also observed that with a bag equipped with such straps, the carrier was capable of walking over longer distances, while being less tired. The posture and the kinematics of walking of the carrier are significantly less altered than with one of the conventional straps, such that said strap has a real added value in terms of ergonomics and reduction of musculoskeletal issues. The shaping frame, the shape of which makes it possible to provide these advantages to the shoulder strap, is simple to manufacture, such that the proposed solution is inexpensive to implement.
Other advantageous characteristics of the invention are listed below. Each of these characteristics can be considered individually or in combination with the characteristics defined above regarding the technical problems that they resolve specifically, and can form the subject, if necessary, of one or more divisional patent applications:
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- 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 whole front frame portion, but also along the whole upper frame portion.
- According to one embodiment, the shape of the inner surface of the frame is geometrically defined by the following characteristics:—the inner surface is caused by a continuous rotation of a segment around its middle, the length of said segment corresponding to the width of said inner surface; and said middle describes a trajectory describing a curve; and which rotation is non-zero and in the same direction along said trajectory.
- 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 trajectory describes a flat curve. The trajectory can thus describe a circular portion, or an ellipsis portion, or a logarithmic curved portion, or a hyperbole portion or an arch portion or a cycloid curve.
- According to one embodiment, the trajectory describes a left curve. The trajectory can thus describe a helix portion, or a rational sextic portion, or a non-rational sextic portion.
- According to one embodiment, the following characteristics also geometrically define the shape of the inner surface of the frame: the angular rotation speed of the segment, when its middle is moved along the trajectory, is uniform and non-zero along the trajectory.
- According to one embodiment, the angular rotation speed of the segment, when its middle is moved 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 extends also the upper frame portion, which rear frame portion is adapted to extend, in use, downwards from the torso of the carrier, from the back face of said carrier;—the rear frame portion comprises a support portion shaped such that, in use, the shoulder strap bears against a rear support surface of the carrier located in a back region of the carrier or at the level of a lateral flank of said carrier.
Another aspect of the invention relates to load-removing equipment on the human body, comprising a left shoulder strap and a right shoulder strap, each of said straps according to one of the preceding characteristics.
Also, another aspect of the invention relates to load-removing equipment on the human body, comprising one single shoulder strap, said strap according to one of the preceding characteristics.
An additional aspect of the invention relates to a method for manufacturing a shoulder strap according to one of the preceding characteristics, comprising steps consisting of:—shaping the shaping frame such that the front frame portion extends downwards from the torso of a carrier from the stomach face of said carrier and that the support portion is located on a front face or on a lateral face of the thorax or of the abdomen of said carrier;—equipping the shoulder strap of the shaping frame.
Other advantages and characteristics of the invention will appear better upon reading the description of a following preferred embodiment, in reference to the appended drawings, made as indicative and non-limiting examples and wherein:
The invention relates to a shoulder strap which is particularly adapted to equipping load-removing equipment on the human body. By “load-removing equipment”, this means any type of accessory, equipped with one or more shoulder straps and which is carried by the human body. This can be a travel bag, a sports bag, a golf bag, a walking bag, a military bag or firefighters' bag, a schoolbag, a baby carrier, a protective jacket (body armor, minesweeper clothing), etc. Generally, this bag is intended to transport a load: clothes, exercise books, equipment including military equipment, oxygen cylinder, fire hose, books, sport or baby accessories, etc.
To improve the comfort in carrying decreased from the feeling of weight of the load carried, the lower end of the rear face of the bag 1 can possibly extend from each side by an abdominal or stomach belt made of two parts 6, 7, which makes it possible to fix the lower part of the bag 1 around the waist of the carrier. A buckle makes it possible to secure the two parts 6, 7 of this belt. The latter is well-known to a person skilled in the art.
In
Each shoulder strap 8a, 8b comprises here an adjustment strap making it possible to adjust the length of the shoulder strap 8. The backpack 1 of
Without the rigidifying frames described above in the description, the straps 8a and 8b are flexible, i.e. easily deformable, manually. These frames make it possible to shape the straps, and rigidify them. Also, the straps 11a and 11b are more rigid—or less flexible—with the frames that without these frames, and/or said frames impress their shape on said straps.
A frame 3 is represented in
According to one embodiment, the frames 3 are thin, i.e. that their transverse cross-section has a width “I” which is greater than their thickness “e” (
In
The frame 3 has elastic properties making it possible for it to be elastically deformed, reversibly. This elasticity makes it possible for the frames 3 to best follow the curvature of the straps 8a, 8b, as well as that of the torso of the carrier 2, with a spring effect, as explained in detail above in the description.
The frames 3 can be obtained by molding or machining. They are, for example, made of:—plastic such as a 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 timber, stratified timber, laminated timber;—etc. Any other material which suits 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 metal material, which core is coated with silicone or another flexible plastic material ensuring an electric insulation in addition to an increased comfort.
In
The frame 3 has an upper portion 30, which is located, in use, at the level of the shoulder 12, 15 on which is installed the shoulder strap 8a, 8b equipped with the respective frame 3. This upper portion 30 is preferably curved in the shape of an arc or of a hook and the curvature of which is adapted to the morphology of the shoulders 12, 15 of the carrier 2. Thus, when the carrier 2 carries the bag 1, the shoulder strap 8a, 8b extends above their shoulder 12, 15. The upper portion 30 has a free end 300 (or upper free end).
This upper portion 30 extends downwards through a front frame portion 31. These two portions 30, 31 here form one single and same part, without discontinuity. All or some of the front frame portion 31 is installed in the shoulder strap 8a, 8b. It extends, in use, downwards from the torso of the carrier 2, from the stomach face of said carrier, whatever the anatomy and/or the morphology of said carrier. In
When a frame 3 is associated with a strap 8a, 8b, this takes the shape of said frame. The frame 3 therefore makes it possible to shape the strap 8a, 8b. This property is used, in the scope of the invention, to create new points or zones to support said strap in a region of the torso of the carrier 2, other than the shoulders 12, 15.
In
In the embodiment of
The trajectory T of
The trajectory T can however be a curve traced in a three-dimensional space—3D curve or left curve—contained in the space (O, x, y, z). By referring to
In
During its movement between the points T0 and T1, and geometrically-speaking, the rotation speed of the segment AB is not zero and can be constant (uniform or equal angular rotation speed along the trajectory T) or inconstant (variable or different angular rotation speed along the trajectory T). Choosing this rotation speed makes it possible to best adapt to the morphology of the carrier 2 and/or to adjust very precisely the location of the support portion 32. For the same reasons, the length of the segment AB (which corresponds to the width of the frame 3) can be constant or vary along the trajectory T, between the points T0 and T1. For example, as illustrated in
In the embodiment of
In
The shape of the frame 3 makes it possible to orient very precisely the support portion 32 parallel to the support zone 24 of the carrier 2. The frame 3 will impress a twisting movement on the strap 8a, 8b such that the latter best follows the curvature of the torso of the carrier 2 and, at the same time, that the support portion 32 reaches a target support zone 24. This support zone 24 can vary according to the type of bag or load-removing equipment and/or according to the morphology, the size, the type and/or the gender of the carrier 2. Furthermore, the specific shape of the inner surface S1 of the frame 3 (and more generally, the specific shape of said frame), makes it possible to offset the straps 8a, 8b frontwards and/or upwards from the collarbones and/or the shoulders 12, 15 of the carrier 2. As appears in
In traditional bags, the straps 8a, 8b pass over the shoulders 12, 15 and the collarbones of the carrier 2, and descend against the chest muscles then pass under the armpits. The shoulders 12, 15 are therefore the main zones for supporting the straps 8a, 8b, the main portion 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 very precisely the support portion 32, towards a targeted support zone 24, and parallel to the latter. The best results, in terms of comfort and of decreasing the feeling of weight of the load carried, are obtained when the support zone 24 is located at the level of the chest muscles of the carrier 2, preferably in the upper or lateral part of said chest muscles.
The action of restricting the strap 8a, 8b being flattened against the support zone 24, induces that said strap does not rest directly on a shoulder 12, 15, nor on a collarbone, nor on a trapezoid of the carrier 2. On the contrary, each strap 8a, 8b bears against the support surface 24 of the carrier 2, so as to apply at least one part (even all) of the load of the bag 1 and of the item(s) transported inside, against said support surface. The load is therefore moved over the support surface 24 which can be more urged than the shoulders 12, 15 without this causing discomfort. The backpack 1 seems a lot lighter. It has been able to be observed that, when a bag 1 comprising shoulder 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 carrier 2. In other words, for one same load, the backpack 1 seems a lot lighter for the individual who carries it.
More specifically, and as illustrated in
In the present description, when it is indicated that the shoulder strap 8a, 8b extends or bears “against” the torso of the carrier 2 (support surface 24), this of course means against the torso or against clothing covering the torso. Likewise, when it is indicated that the shoulder strap 8a, 8b does not rest on a shoulder 12, 15, this means that it could be in contact, at the level of the shoulder, with clothing of the carrier 2.
Different techniques making it possible to secure the frames 3 to the straps 8a, 8b will now be explained in detail, in reference to
In the embodiment of
In reference to
In
In an embodiment variant, the upper frame portion 30 can be extended by a rear frame portion, which rear frame portion extends, in use, downwards from the torso of the carrier 2, from the back face of said carrier. The frame 3 has, in this case, an arch 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 portion of the front branch and an upper part of the rear branch. The front and rear branches can be of the same length or of different lengths.
Like for the front frame portion 31, this rear frame portion comprises a rear support portion shaped such that, in use, the shoulder strap 8a, 8b (or directly, said rear frame portion) bears against a rear support surface of the carrier 2 located in a back region of the carrier (back, lumbar) or at the level of a lateral flank of said carrier. The frame 3 thus has two separate support portions.
Along the rear frame portion, the inner surface S1 of the frame 3 (and possible its outer surface Se) can also be caused by the continuous rotation of a segment about its middle, which center has a trajectory T describing a curve. The rear frame portion is thus twisted. Preferably, the front and rear frame portions are not twisted in the same direction, so as to optimize the supports at the front support surface level of the rear support surface. The rear frame portion can also not be twisted.
Such a frame 3 with two branches makes it possible to surround the torso of the carrier 2 at the level of two support zones: a first stomach region where the front frame portion supports and a second back region where the rear frame portion supports. These two support zones are located on the same side of the torso (on the right or on the left of the sagittal plane of the carrier 2). When the carrier 2 installs the bag 1 on their shoulders, the front frame portion and the rear frame portion of each frame is deviated at the level of the torso of the carrier 2 and act like jaws by elastically deforming, with a spring effect, to surround, without injuring them, said torso.
When each of the straps 8a, 8b is equipped with a frame 3 with two branches, a double clamping effect is obtained: the frame 3 engaging with the right strap 8a acts like a clamp in the right part of the torso and the frame 3 engaging with the left strap 8b acts as a clamp in the left part of said torso. All or some of the weight of the load is thus moved and distributed at the level of these two new support zones.
A clamping effect can also be obtained (to the right, to the left, or diagonally from the torso), with one single frame 3 with two branches, which makes it possible to equip a single-strapped bag.
The arrangement of the different elements and/or means and/or steps of the invention, in the embodiments described above, must not be understood as requiring such an arrangement in all the implementations. In any case, it will be understood that various modifications can be applied to these elements and/or means and/or steps, without deviating from the sense and the scope of the invention. In particular:
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- The transverse cross-section of the upper frame portion 30 can be different from that of the front frame portion 31. The transverse cross-section of the front frame portion 31 can in particular be wider than that of the upper frame portion 30 so as to increase the surface of the support portion 32.
- The frame 3 can possibly have a straight portion, the length of which is marginal with respect to the total length of said frame (≤5% of the total length).
Furthermore, one or more characteristics outlined only in one embodiment can be combined with one or more other characteristics outlined only in another embodiment. Likewise, one or more characteristics outlined only in one embodiment can be generalized to the other embodiments, even if this or these characteristic(s) is/are described only in combination with other characteristics.
Claims
1. A should strap of a carrier, comprising: wherein along the upper frame portion and the front frame portion, the inner surface of the frame has the shape of a Moebius strip portion, which inner surface is, in use, oriented towards the body of the carrier.
- a shaping frame having one same inner surface and one same outer surface,
- the shaping frame comprising: an upper frame portion located, in use, at the level of the shoulder on which the shoulder strap is installed, a front frame portion which extends the upper frame portion, which front frame portion extends downwards, and the front frame portion comprises a support portion shaped such that, in use, the shoulder strap bears against a support surface of the carrier,
2. The shoulder strap according to claim 1, wherein:
- 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 whole front frame portion, but also along the whole upper frame portion.
3. The shoulder strap according to claim 1, wherein the shape of the inner surface of the frame is geometrically defined by the following characteristics:
- the inner surface is caused by a continuous rotation of a segment about its middle, the length of said segment corresponding to the width of said inner surface, and
- said middle describes a trajectory describing a curve, and
- which rotation is non-zero and in the same direction, along said trajectory.
4. The shoulder strap according to claim 3, wherein the trajectory describes a flat curve or a left curve.
5. The shoulder strap according to claim 4, wherein the trajectory describes a circular portion, or an ellipsis portion, or a logarithmic curved portion, or a hyperbole portion, or an arch portion of a cycloid curve.
6. The shoulder strap according to claim 4, wherein the trajectory describes a helix portion, or a rational sextic portion, or a non-rational sextic portion.
7. The shoulder strap according to claim 3, wherein the following characteristics also geometrically define the shape of the inner surface of the frame:
- the angular rotation speed of the segment, when its middle is moved along the trajectory, is uniform and non-zero along said trajectory, or
- the angular rotation speed of the segment is variable and non-zero along said trajectory.
8. The shoulder strap according to claim 3, wherein the length of the segment is constant or variable along the trajectory.
9. The shoulder strap according to claim 1, wherein the front frame portion has a free end having a flared shape.
10. The shoulder strap according to claim 1, wherein the upper frame portion has a free end curved upwards.
11. The shoulder strap according to claim 1, wherein:
- a rear frame portion also extends the upper frame portion, which rear frame portion is adapted to extend, in use, downwards from the torso of the carrier, from the back face of said carrier,
- the rear frame portion comprises a rear support portion shaped such that, in use, the shoulder strap bears against a rear support surface of the carrier located in a back region of the carrier or at the level of a lateral flank of said carrier.
12. The shoulder strap according to claim 1, wherein the outer surface of the frame has the same shape as the inner surface of said frame.
13. A load-removing equipment on the human body, comprising a left shoulder strap and a right shoulder strap, wherein each of said straps is in accordance with claim 1.
14. A load-removing equipment on the human body, comprising one single shoulder strap, wherein said strap is in accordance with claim 12.
15. A method for manufacturing a shoulder strap according to claim 1, comprising:
- shaping the shaping frame such that the front frame portion extends downwards from the torso of a carrier, from the stomach face of said carrier and that the support portion is located on a front face or on a lateral face of the thorax or of the abdomen of said carrier,
- equipping the shoulder strap of the shaping frame.
Type: Application
Filed: Jun 1, 2020
Publication Date: Jul 28, 2022
Applicant: GRAVIBAG (Sens)
Inventor: Mohammed ERRAFI (Marseille)
Application Number: 17/615,783