FR3025077A1 - ERGONOMIC CARTABLE DEVICE FOR CHILDREN OR ADOLESCENTS, AND BACKPACK FOR ADULTS - Google Patents

Abstract

The invention provides a backpack for children, comprising a jacket with side straps. This binder further comprises at least one ventral holding belt which is made of an elastic material. It is anchored on each side of the envelope in at least two ventral anchor points separated by a holding height of at least a quarter of the height of the binder. The experimentation of such a binder by "embracing" shows that it is possible to support the recommended weights by removing the straps on the shoulders; and therefore reduce the load on the upper part of the spine. According to one feature, the envelope includes at least one inner wall defining at least one anterior or main compartment which is adjacent to the lower bottom and the back panel of said casing. Such a compartment is arranged to have a rectangular parallelepiped shape of a thickness less than its height and width, and of determined dimensions to accommodate one or more books, binders and / or notebooks. Preferably, the binder comprises one or more complementary compartments located behind and / or above said front compartment. Such a complementary compartment has dimensions determined to not be able to accommodate a book or a binder, or even a notebook or a binder. According to another feature, the briefcase comprises a grip handle provided with a dynamometric device arranged to provide a visible measure of the weight of the schoolbag. Optionally, the briefcase further comprises an additional independent compartment that is removably attached to the shoulder straps and / or the waist strap on the front of the wearer.

Description

- 1 - "Ergonomic schoolbag device for children or adolescents, and backpack for adults" The invention provides a backpack, particularly suitable for the growth of the child and the physiology of the spine, including a " envelope with side straps ". According to the invention, this binder further comprises at least one ventral holding belt which is made of an elastic material. This lap belt is anchored on each side of the casing in at least two ventral anchor points separated by a holding height of at least a quarter of the height of the binder, or even the third or half. According to another feature of the invention, the envelope includes at least one inner wall defining at least one anterior or main compartment which is adjacent to the lower bottom and the back panel of said casing. Such a compartment is arranged to have a rectangular parallelepiped shape of a thickness less than its height and width, and of determined dimensions to accommodate one or more books, binders and / or notebooks. Preferably, the binder comprises one or more complementary compartments located behind and / or above said front compartment. According to this feature, such a complementary compartment has dimensions determined to not be able to accommodate a book or a binder, or even a notebook or a binder. According to yet another particularity, the binder comprises a grip handle provided with a dynamometric device arranged to provide a visible measure of the weight of the binder. Optionally, the briefcase further comprises an additional independent compartment that is removably attached to the shoulder straps and / or the waist strap on the front of the wearer.

State of the art The invention relates to the field of school bags, that is to say of luggage designed and made specifically to allow more particularly children and adolescents to carry books and / or notebooks and / or binders 3025077 - 2 - necessary for their one-way trip and / or return between home and school (ie up to about 10 years old) or college (ie up to about 15 years old), in France and in many countries, the organization of work and educational programs is based on the use of class 5 books and / or notebooks, and recently digital tablets and weight computers that may be important. In many cases, students must use these books and notebooks both in the school where the classes are held, and at home to study or do additional work.

10 Books and notebooks, stacks of sheets of paper or cardboard, are rather heavy objects in relation to their volume. Transporting several to each trip is a significant weight, especially for institutions where several different courses take place the same day, and therefore where you have to carry several books and several notebooks, typically at least one per course. A schoolbag, according to its age and its course of the day, can often weigh between 5kg and 10kg, see more. For a long time, there are schoolbags in the form of a semi-rigid rectangular bag well adapted to the shape of the books, and provided with two straps to carry the bag as a hiking backpack. However, the weight distribution on both shoulders and the adjustment of the straps are insufficient given the excessive weight transported. In addition, the behavior of the child during his movements, run or jump for example, significantly increases the effect of this load on its musculoskeletal structure.

25 For example in France, the circular of January 2008 of the Minister of National Education, indicates that the weight of school bags is a public health problem. It states that it should not exceed 10% of the body weight of children, and therefore be reduced by 50% compared to current habits.

30 Indeed, the physiological data of the child's development indicate that: - The vertebrae of the child are ossified only at the age of 14 years for girls and 15 years for boys. 3025077 - 3 - The intervertebral discs are harder than the vertebral growth cartilages. Thus, scientific studies clearly show the impact of weight on the deformity of discs and the growing spine; and in particular the existence in 50% of adolescents of pre-lesions that will prove true herniated discs in adulthood. Unfortunately, it turns out that 80% of children in elementary and middle schools wear satchels that are too heavy, since the average weight carried 10 each day exceeds 20% of their body weight. Thus, there is a real public health interest to change this situation. Numerous studies and attempts have been made to this end, on the one hand seeking to limit the amount of books that students need to carry, or think they have to carry. However, in the case of a wide variety of factors involving many stakeholders on a daily basis, improvements are difficult to implement and impose, and therefore often temporary and generally insufficient.

In this context, the design of the binders is therefore a delicate and relevant question. Briefcases used by professionals are not intended to be worn on the back, and rarely for more than ten minutes in a row. For their part, although hiking backpacks are sometimes very technical products and very studied, their design does not correspond to the context of use by a growing child and various school uses. For example, they are intended to carry mainly clothing, while satchels must carry heavy and rigid books and notebooks. The best studied backpacks are provided for long but quiet, sometimes hours, trips by adults. On the contrary, the binder is used for one hour at most, but by a child whose growth is not over and whose behavior is much more agitated and unpredictable. 3025077 - 4 - Thus, the school bag for children or teenagers is a particular area with specific constraints. In this use, these other products are not usable satisfactorily, and their technologies are often irrelevant. Although personal tastes and fads cause the widespread use of various bags such as shoulder bags or small backpacks, and other bags such as handbags, these products are often chosen by older users are not chosen based on the actual needs of the school context nor on the basis of knowledge of physiology for health. Similarly, the musculature of adults working all day long is not sufficiently prepared to carry a heavy load. An object of the invention is to overcome all or part of the disadvantages of existing binders, and to help reduce the stress on the spine by the schoolbag of a child or adolescent, or the backpack of an adult in his regular use. DESCRIPTION OF THE INVENTION The invention proposes a backpack for a child, comprising a flexible or semi-rigid envelope comprising a dorsal anterior panel, which is reclosable around a storage volume. This binder is of a type provided with at least two side straps each fixed to an upper anchorage point at the top and a lower anchorage point at the bottom of said envelope, for carrying said binder. According to the invention, this binder further comprises at least one ventral waistband which is made of an elastic material, for example more than 20% elongation before deterioration or breakage, and for example between 5% and 20% d elongation for a traction equivalent to twice the maximum weight of the schoolbag, for example for a maximum weight between 3kg and 6kg. This ventral holding belt is anchored on each side of the envelope in at least two upper and lower belly anchor points, which are separated by a so-called holding height of at least one quarter of the height of the binder, for example the height of the storage volume or the height between the bottom of the storage volume and the upper anchoring points of the shoulder straps. Preferably, this height 3025077 - 5 - of maintenance represents at least one third or even half of the height of the binder. According to the embodiments, the ventral anchor points may include the lower strap anchor points. The briefcase according to the invention thus allows a real "interlacement" 5 of the storage volume and its application in permanent contact with the back of the wearer. A reduction of the lever arm exerted by the weight of the schoolbag is obtained, the impacts are reduced, and the friction better participate in the support of the load. Thus, even with respect to the ventral strap backpacks 10 specialized for hiking, which are however a different technical field and clearly target an adult clientele and fully developed and prepared for the effort on the musculoskeletal level, the briefcase according to the invention brings a contact on a region much more distributed and more stable than on the narrow or even linear band which is applied by the unique anchoring of the ventral straps existing on such specialized bags. Moreover, the experimentation by the inventors of the wearing of such a binder by "embracing" has highlighted the fact that it is even possible to support the recommended weights (10% of the weight of the body) by removing 20 straps on the shoulders, that is to say only with the belt. This is an important indication that the invention can significantly reduce the load generally exerted on the upper part of the spine through the shoulder straps, even if they remain of interest from a practical and dynamic point of view.

The features of the invention apply to specialized luggage for the transport of school loads by children. They also apply to carrying luggage of different types of loads by adults, for example with certain heavy and bulky loads handled similarly to books or notebooks, such as a laptop. For children or adolescents as for adults, the advantages of the invention allow such a load port to be better adapted to the current evolution of the individuals and to the recent evolutions of the body diagram, which are modified and weakened because of the increased time spent sitting, especially at work, which weakens the spine. Indeed, recent scientific studies show that the prolonged maintenance of the seated position disrupts the body's recovery regimen and causes a loss of vigilance of the back musculature. Faced with these new uses of life and work, including the widespread use of computers that condition immobility, excess load carrying becomes a Public Health problem increasingly serious.

Various features of the invention are here listed, which can be combined with each other. According to a feature of the invention, at least one ventral retaining belt, said posterior, is anchored to the casing at ventral anchoring points located on a panel forming a rear wall of said envelope or compartment within said envelope. The traction of this posterior belt thus applies directly to this posterior wall. Its action is thus pressed against the back of the wearer not only the back panel of the envelope but also the contents of this envelope, or compartment concerned. For example, pressing on the contents of the envelope or compartment creates a compaction of this content which gives it greater stability of form and behavior, for example by pressing the books together against each other. prevents slipping on one another. According to another feature of the invention, the envelope includes at least one inner or outer wall defining at least one front compartment which is adjacent to the bottom bottom and the back panel of said casing, for example a single compartment in a single volume. , or several compartments juxtaposed with each other one behind the other or one next to the other and adjacent to the back panel. Such a compartment is arranged to have a rectangular parallelepiped shape of a thickness less than its height and width, and of dimensions determined to accommodate one or more books and / or notebooks. The user is thus encouraged to arrange the books and notebooks, which are generally the heaviest items in a schoolboy's binder, in the compartment that is closest to the back panel, and therefore where they will be the best stabilized and will create the weakest lever. Preferably, this compartment is situated in front of a posterior ventral support belt, which therefore specifically clings the heavier elements. More particularly, the anterior compartment preferably has a thickness determined to be able to receive a limited thickness of books and / or notebooks, which thickness is calculated to represent a maximum weight determined.

10 It is thus impossible or difficult for the user to store in the binder more books or notebooks than the thickness of this previous compartment allows. Books and notebooks are generally the most dense elements in a binder, the total weight of the binder is thus limited to an approximate value which depends directly on this number of books and 15 notebooks, for example depending on the density of the books and / or notebooks for which it is intended. This maximum weight value that can be contained in the binder can thus be adjusted by these dimensions, for example according to the age or weight of the user. According to yet another particularity of the invention, the envelope 20 comprises a dynamometric device arranged to provide a visible measure of the weight of the schoolbag when said schoolbag is raised or suspended by a gripping handle at the top. In some embodiments, the handle is formed by or attached to one or both side straps.

The bearer of the binder, but also other persons who surround him and / or have it under his responsibility, can easily know the total weight of the binder, even without or against the will of the wearer. In addition to improving the carrying of the binder and limiting the weight it contains, the invention thus makes it possible to make more visible the problem posed by excessive weight, which is already recognized by the Ministry of National Education. The invention thus makes this problem more difficult to hide or dodge, and thus allows a better awareness of all. Another feature of the invention is provided, wherein the binder further comprises an additional compartment, for example in the form of a pocket, which is independent of the envelope of said binder and is attached to the shoulder straps. and / or the ventral holding belt, 5 on the front of the carrier, by detachable fastening means fast maneuver. This additional pocket thus allows the user to easily carry additional objects that could not enter the main envelope. It constitutes a kind of planned overcoming of the expected weight, which allows a certain flexibility in the carried weight without losing sight of the reality of this overtaking. This overtaking is clearly visible to the user, since he realizes that it is necessary for him to use the additional compartment. It is also visible to those around it, for example parents or teachers, 15 This front cover also allows to have better access to its content than the binder when on the back. In practice, this option facilitates access to extra-curricular documents and objects (transport card, notebook, notebook and other objects of frequent access) while allowing the maintenance of the port by embracing since these 20 objects are thus accessible. without access to the main bag. This prevents the child from wearing his bag on one shoulder while using these objects and before putting them back. In addition, the position of this content at the front of the wearer allows a better load distribution between the front and the back of the wearer and thus to balance the muscular efforts. Optionally according to the embodiments, similar to the compartments of the main envelope, this additional compartment is made with dimensions that prevent to insert books or notebooks, or on the contrary dimensions that allow it but in a 30 maximum quantity determined according to a maximum permissible weight. Thus, the invention makes it possible in particular to reduce the stresses exerted on the spine for a given load and thus to wear it more efficiently and less damaging to its current health and especially future, in the specific context of the spine. a schoolbag characterized by its type of load and the type of use that is made of it. It also makes it easier to limit the load borne by the child. These elements indeed bring other elements public health insofar as these 5 means participate in the prevention and the fight against the lumbago of the young adult. Various embodiments of the invention are provided, integrating, according to all of their possible combinations, the various optional features set forth herein.

List of Figures Other features and advantages of the invention will become apparent from the detailed description of an embodiment which is in no way limitative, and the appended drawings in which: FIG. 1 is a schematic diagram with a view to side which illustrates part of the forces applied to a schoolbag according to the invention; - FIGURE 2 is a perspective diagram from the front, which illustrates an exemplary embodiment of the invention with independent side straps of the ventral waistband; FIGURE 3 is a diagram from the rear which illustrates the operation of the torque handle in an exemplary embodiment of the invention; FIGURE 4 is a rear perspective diagram illustrating an exemplary embodiment of the invention with side straps independent of the ventral waistband, for example that of FIGURE 2, comprising a single dorsal compartment and an upper complementary compartment; FIGURE 5 is a side diagram illustrating an exemplary embodiment of the invention with side braces independent of the ventral waistband, comprising a two-part dorsal compartment and an upper complementary compartment; FIGURE 6 is a front perspective diagram illustrating an exemplary embodiment of the invention with removable upper side straps clinging to the two portions of the ventral waistband; FIGURE 7 is a perspective diagram from the back of the binder of FIGURE 6; FIGURE 8 is a front diagram, which illustrates an exemplary embodiment of the invention with fixed upper side straps clinging to the two portions of the ventral waistband; FIGURE 9 is a front diagram, illustrating an exemplary embodiment of the invention with upper side straps secured together and carrying the torque handle, and clinging to the fastening buckle of the two parts of the lap belt. holding, which is made and anchored discontinuously but distributed; FIG. 10 is a front perspective diagram illustrating an embodiment of the invention, for example that of FIG. 6, in a variant with an additional compartment. DESCRIPTION OF EXAMPLE EMBODIMENT FIG. 1 schematically illustrates a number of forces involved in carrying the briefcase according to the invention, in an exemplary embodiment with side straps independent of the ventral waistband. which is illustrated in FIGURE 2. The explanations presented herein for this exemplary embodiment are also valid for the other embodiments presented below, which share the same main features and advantages. Since the weight of the schoolbag is generally suspended on one or both shoulders, moments of forces proportional to the weight P1 and to the lever arm D3 are exerted on the various levels of the spinal column. This lever arm is the horizontal distance D3 which separates the center of gravity G1 from the bag 1 and the bearing point G3 of the main reaction force R3 of the spine 90. The more the weight is moved away from the column, the more the moments strengths are important. In addition, in order to balance the moment of force of the load, the child must lean forward to use muscles that do not participate in the straightening of the back; which has the effect of increasing or doubling this load by a horizontal component R31 and to work the body in a posture 5 which is even less effective and healthy. Under the effect of these increased and poorly positioned loads, the muscles get tired quickly, and the load port becomes "PASSIVE". It is then supported directly by the skeleton, instead of being dynamically managed by the muscles. In addition to the muscle pain caused by the contractures, the stresses are localized according to its morphological type, and this location of constraints constitutes areas of overwork with age. That is to say, it can aggravate the initial weaknesses of this conformation and be the source of pre-lesions that will become chronic lesions for the whole life.

It is useful to remember that in prolonged sitting position, movements of the pelvis and spine around the balance participate in the maintenance of the neuromuscular regimen of recovery and vigilance of the deep muscles, which are useful for the wearing of charge. Given the duration of the child's sitting position (4000 hours / year) because of the new uses of life and work, and the bad postures frequently adopted because of the habits acquired and the absence of ergonomic furniture, this neuromuscular pattern is already particularly proven and unsuitable for carrying loads while traveling.

Enlacement In the binder 1 according to the innovation of the invention of the charging port by embracing, the elasticity with a significant elongation provided by this ventral support belt 3, possibly with an adjustable length adjustment, allows this belt 3 to be in permanent tension t3, without disturbing the wearer 9, despite shocks or jerks caused by the movements of the wearer, even abrupt and important. This permanent tension is thus applied to the envelope 10 of the binder, which keeps it in permanent contact with the back 91 of the wearer 9. The shocks between the back and the binder are removed or decreased, and the distance between the center of gravity of the binder and the axis of the spine 90 of the wearer is kept permanently at a minimum, and therefore the lever arm D3 to which the weight P1 of the binder applies.

The vertical extent h3 on which this belt 3 is anchored to the binder allows this holding in contact to take place smoothly over a two-dimensional contact surface c91 of the back 91 representing a high height h91. This support height allows for better friction so less slippage along the back. The support against this dorsal contact surface c91 thus allows a reaction force R1 which balances a portion of the weight P1 of the binder, furthermore applied with a lower lever arm D1 than that D3 applied to the reaction R3 supported by the straps 2 resting on the shoulders of the wearer. Simultaneously, this belt 3 prevents or limits the rotation of the load backwards, thus reducing, for example, the jerks and backward forces applied to the wearer's shoulders and which require an R31 effort towards the front. Thus, even with respect to specialized backpacks for hiking, which are nevertheless of a different technical field and clearly aim at an adult and fully developed musculoskeletal clientele, the briefcase according to the invention provides a contact on a region much more distributed and more stable than on the narrow or even linear band which is applied by the unique anchoring of the ventral straps existing on such specialized bags.

In addition, as illustrated in FIGURE 1 and FIGURE 5 for the binders 1, and preferably in all embodiments, the back panel 11 has a non-uniform thickness Ell over its height, or includes such an insert or is attached thereto. to such an element, which can be more or less rigid or elastically deformable. The vertical profile of this panel or back insert 30 is determined to be complementary to the profile of the back 91 of the wearer, preferably with at least one complementary convexity of the lumbar lordosis 92. This shape facilitates the application of a continuous support on a high back height, and allows at the same time a wide contact between the binder and the sacro-lumbar region 92 of the wearer, typically in the lower part of the lumbar lordosis. This contact c92 increases the friction force R1 mentioned above, but also allows this part of the body to support a portion R2 of the vertical component generated by the weight of the bag, and with an even smaller lever arm D2. The efforts R3 and R31 applied to the shoulders and therefore to the spine are further reduced. FIGURE 1 to FIGURE 2, FIGURE 4 to FIGURE 7, and FIGURE 10 illustrate a preferred but not mandatory feature that can be implemented in all embodiments. According to this feature, the binder 1, the to the according to the invention comprises at least one ventral belt 2, 21, 22, said rear, which is anchored to the casing 10 at the ventral anchor points 321, 322, 331, 332 located on a panel forming a rear wall 13 of said casing as illustrated in the figures cited, or a rear wall of a compartment within said casing. The traction t3 of this posterior belt 3 thus applies directly to this posterior wall, and its action presses against the back of the wearer not only the dorsal panel of the envelope but also the contents of this envelope, or at least the compartment concerned. For example, the pressure on the contents of the envelope or the compartment creates a compaction of this content which gives it a greater stability of form and behavior, for example by the support of the books against each other which makes them prevents slipping on one another. Optionally but not mandatory, which can be combined with the other features described herein, the briefcase according to the invention comprises several ventral support belts. Thus, in the exemplary embodiment illustrated in FIG. 5, the binder further comprises a second, aforementioned, ventral holding belt 4 which is anchored to a panel 14 situated in front of the panel 13. anchorage on which is anchored the posterior ventral belt 31, 32. In this example the second belt 4 can also be described as a posterior belt since it is anchored to an inner wall 14 which forms the rear of the front compartment 101 most forward. This is therefore a belt of "posterior" nature, but which forms an "anterior" belt relative to the posterior belt 3 which is anchored behind it. Alternatively, and not shown here, this anterior belt 10 is simply anchored on the dorsal panel of the envelope, or preferably on the back of the anatomic backdrop 11 if it exists. The traction of this anterior belt 4 will press this back panel permanently against the back of the wearer, which improves comfort and limits slippage between the two.

The load restraints provided by the rear waist are particularly improved by the presence of an additional front waistband, for example because the different compartments 101, 102 are each held individually. The vertical movements between two compartments are limited, tension adjustment is easier and more independent, and the back panel remains in better contact with the back. Possibly, this (these) belt (s) can be anchored (s) discontinuously or even punctual, for example in only two anchor points.

Preferably, however, as in the exemplary embodiments presented herein, the belt (s) 3, 31, 32 are anchored to the binder 1, 1a, 1b, 1c, 1c continuously between the two points. upper half-anchoring 321, 331 and lower 322, respectively 332. Alternatively, a semi-continuous anchoring is carried out, for example as illustrated in FIGURE 9, on a plurality of points or ventral anchoring portions forming one or more regions whose cumulative height h39 represents at least 30% or even 50% of the distance h3 between said two upper and lower ventral anchor points. 3025077 - 15 - The traction of this ventral support belt thus applies regularly over the entire height h3. The contact c91, c92 with the back is reinforced, and the maintenance of the load more regular and more reliable, for example when the transported objects rise less high than the upper ventral anchoring point 311, 321. Preferably but not obligatorily, ventral waistband 3, 4 has in its part on the front of the wearer a height h3 of at least 10cm, or even at least 15cm. Load Optimization FIG. 4 illustrates a preferred but not mandatory feature that can be implemented in all embodiments. According to this feature, the envelope 10 of the binder 1, lb comprises several compartments. On the one hand, one 101 of these compartments is said to be anterior because it is located adjacent to the back panel 11, ie as far forward as possible of the binder. It is also preferably situated at the bottom of the volume enclosed by the envelope, for example adjacent to the lower panel 12. In the present example, this anterior compartment 101 is delimited by the bottom 12 and the rear 13 of the envelope, and only by the side walls and by a ceiling 15. This front compartment 101, or principal, has dimensions in width L101, L104 and height H101, H104 which are determined to accommodate one or more books or notebook 81. On the other hand , the binder comprises one or more complementary compartments located behind and / or above said front compartment. In the present example, the binder 1 comprises a complementary compartment 103 which is situated above the anterior compartment 101 from which it is separated by the horizontal inner wall 15. According to this characteristic, such a complementary compartment 30 has specific dimensions, here through its height H103 and its thickness E103, to not be able to accommodate a book or a binder, even a notebook or a binder (for example to be able to accept a small binder or notebook but not a big one). FIG. 5 shows an exemplary embodiment in which the schoolbag also includes such an "anterior" compartment which is formed by two volumes 101 and 102 separated by an inner wall 14. These two compartments are both located at the bottom of the envelope and closed downwards by the bottom 12, and their assembly is well adjacent to the anatomical bottom 11. Their height h101 and their width are provided to be able to receive books and notebooks 81. Optionally, the volume 101 the foremost front of the main compartment is sized to accommodate larger objects, for example books or large file cabinets (for example in A4 format), while the rearmost volume 102 is dimensioned to accommodate smaller books, notebooks or binders (eg 17x22cm format), giving it a lower height than h101 of the volume before 101.

As in the example of FIGURE 4, they are surmounted by a "complementary" compartment 103, whose combined dimensions of height h103 and e103 do not accommodate books, but only objects 82 of smaller dimensions. Books and notebooks are generally the heaviest objects that are typically carried by a schoolboy. Now they all have a flat shape whose two external dimensions are both important, and are difficult or impossible to bend or roll, in any case without visibly damaging them. Such complementary compartments 103 are, for example, designed so as to have no more than one L103 dimension which exceeds that of a conventional book or notebook. They can thus accommodate many objects such as a pencil case or various accessories 82, but the user can not carry books or notebooks. Thus, while allowing books and notebooks to be transported in the most suitable compartment for the health of the wearer, such a binder also offers an additional volume which makes it possible to transport other varied objects, but which is difficult or even impossible. use to add other books or notebooks that could load the binder significantly beyond a maximum weight chosen at design 3025077 - 17 - As an example, standardized formats of books, or sheets or notebook are for example 21x29,7cm for a sheet of A4 or a large notebook, 17x22cm for notebooks of smaller size, and similar dimensions for the classbooks.

5 or the previous compartments which are intended for them can thus have dimensions of the order of 25x40cm in width and height to see accommodate these formats vertically, and a thickness of the order of 10cm to 25cm receive the maximum number of these formats corresponding to the maximum weight chosen for the binder.

The other potentially transported objects have many different and unpredictable dimensions. However, they generally have a substantially lower overall density than paper, and are less likely to accumulate beyond a certain amount. For example, the one or more complementary compartments have only one dimension that exceeds 15cm, and may for example have a cylindrical or rectangular shape of the order of 10x10x25cm, or 15x15x20cm, or 5x15x30cm. For example, the "previous" compartment or compartments, the only ones that can accommodate books and notebooks, are sized so that the total foreseeable weight of the binder does not exceed the limits recommended by the French National Education Circular, namely: : - 10% of the average weight of a child in elementary school, ie 10% x 25 kg = 2.5 kg - 10% of the average weight of a child in middle school, ie 10% x 40 kg = 4 kg.

In FIGURE 10 is illustrated an optional feature that can be implemented in all embodiments. According to this feature, the briefcase further comprises an additional pocket 6 independent of the envelope 10 of said briefcase and which is fixed on the shoulder straps 21, 22 and / or the ventral waistband 3, 31, 30 32, on the front of the carrier 9, by quick-release detachable fastening means 61. Optionally, the binder comprises several additional pockets that can be hung together visibly. Alternatively, there are several pockets of different sizes and having a different color or shape, and only one at a time can be hung on the binder. This feature allows users to have additional storage space in addition to that of the main envelope 10.

5 It allows them to reduce the constraints imposed by such physiological standards, so do not discourage them in the use of the schoolbag according to the invention, while still providing the other ergonomic benefits it allows. Torque Handle 10 In FIGURE 3 is illustrated an exemplary embodiment of a dynamometric device as preferably provided in the briefcase according to the invention. In this example, the dynamometric device comprises an elastic member 51, for example an elastic textile for a metal spring 15, which is attached to the grip 5 and then extends downwardly through a sliding aperture 53 formed of upper part of the casing 10, here at the top of the dorsal anterior panel 11. This elastic element 51 slides in a sliding space, here a sheath inside the back panel 11, and is fixed to said casing at a point 20 anchor 54 located lower than said sliding aperture. This elastic element 51 carries a plurality of distinct marks 55a to 55e each corresponding to a determined weight Pla to Ple of the schoolbag 1, for example marked with numbers or letters, or preferably with colors ranging for example from green for the weight the most light 25 Pla red for the heavier Ple. Each of these marks is on the elastic element in a position determined to be visible above the holding opening, under the effect of an elongation of the elastic element 51 caused by the weight of the schoolbag when it is lifted by said handle 5, if and only if the weight of the schoolbag exceeds the weight Pic corresponding to said mark 55c. The elastic element is for example slidably included in the thickness of the back panel. For example also, the elastic member is similarly included within one or both straps. Alternatively, the marks are arranged on an element which is displaced with respect to a fixed element under the effect of the elongation of the elastic element 51. In a variant illustrated in FIG. 9, the grip 5 5 is fixed at the end of the upper half-shoulder straps 21 and 22 right. These are fixed together on a piece that hooks by quick coupling with the belt, here with the buckle 33 of fast attachment of In this example, the dynamometric handle 5 is attached to two elastic members 51 which each slide in a lateral half-shoulder and protrude by a length which varies according to the force applied to the two half-belts 21 and 22. handle. In this example, the straps themselves are not elastic and do not participate in the dynamometric measuring chain. The handle can be used, for example, to hook the briefcase to a hook, when the shoulder straps are detached from the waistband buckle 33. Alternatively, the dynamometric device includes the shoulder straps, and thus allows to know in real time applied to the straps on the shoulders of the wearer. According to a variant illustrated in FIG. 7, the dynamometric device 20 is formed by an electronic sensor, the result of which is displayed in a known manner, for example by a screen 59. Example of various variants Preferably, in the binder 1, the according to the invention the at least one ventral holding belt 3 is formed in two half-belts 31, 25 32 joined at the level of the belly of the carrier 9 by detachable fastening means 33. The briefcase 1, DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 to FIGURE 5 is realized with side straps 21, 22 independent of the one or more ventral support belts 3, 4, which allows, for example, separate adjustments. Alternatively, FIGURE 6, FIGURE 7, FIGURE 8 and FIGURE 10 illustrate a preferred but not mandatory feature, which can be combined with the other features herein set forth. According to this characteristic, each half-belt 31, 32 of the binder 1b is in fact fastened, on the side of the ventral fastener 33, to the side strap 21, respectively 22 which corresponds to it. In such a situation, it can thus be considered that the lower anchorage of the side straps 21, 22 is formed by the anchoring points 311 to 312, respectively 321 to 322 of the ventral holding belt 3, 31, 32 the most low. More particularly, the lateral straps 21, 22 of the Satchel lb are fixed on the half-belts 31, 32 respectively by detachable fast-acting fastening means 213, 223.

Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention.

Claims (15)

REVENDICATIONS1. Schoolbag (1, la) or backpack for children, teenagers or adults, of the type comprising a flexible or semi-rigid envelope (10) comprising a dorsal anterior panel (11), and which is reclosable around a volume of storage and provided with at least two lateral straps (21, 22) each fixed to an upper anchorage point (211, 221) in the upper part and to a lower anchor point (221, 222) in the lower part of said envelope, for carrying said binder on the back, characterized in that it further comprises at least one ventral holding belt (3, 31, 32) which is made of an elastic material and is anchored on each side of the envelope in at least two points said upper (321) and lower (322), which are separated by a so-called holding height (h3) of at least a quarter of the height (hl) of the binder. 2. Schoolbag (1, la, lb, lc, le) according to the preceding claim, characterized in that the at least one ventral holding belt (3, 31, 32) is anchored to the casing (10) continuously between the two upper (321, 331) and lower (322, respectively 332) ventral anchoring points, or on a plurality of ventral anchoring points forming one or more regions whose cumulative height represents at least 30% or even 50% the distance (h3) between said two upper and lower ventral anchor points. 3. Satchels (1, the to) according to any one of the preceding claims, characterized in that the ventral holding belt has in its portion on the front of the wearer a height (h3) of at least 10cm, or at least 15cm. 4. Satchel (1, la) according to any one of the preceding claims, characterized in that the back panel (11) has a thickness (E11) not regular over its height, the vertical profile is determined to be complementary to the profile the back (91) of the wearer, preferably with at least one convexity complementary to the lumbar lordosis (92). 5. Satchel (1, la) according to any one of the preceding claims, characterized in that at least one ventral belt of maintenance, said posterior, is anchored on the casing (10) at points of ventral anchorage (321, 322, 331, 332) located on a panel forming a rear wall (13) of said envelope or a rear wall (14) of a compartment (101) within said envelope. 10 6. Satchel (1a) according to the preceding claim, characterized in that it further comprises at least a second ventral waistband (4), said anterior, which is anchored to a panel (14) located in front of the panel ( 13) anchoring the posterior ventral belt (31, 32) 15 7. schoolbag (1, la) according to any one of the preceding claims, characterized in that the casing (10) comprises a dynamometric device arranged to provide a visible measure of the weight of the schoolbag when said binder is raised by a handle 20 (5) located in the upper part. 8. Satchel (1, 1d) according to the preceding claim, characterized in that the dynamometric device comprises an elastic element (51) which is fixed to the handle (5) and then extends through a sliding opening 25 (53) formed in the upper part of the casing (10) and is fixed to said casing in at least one anchoring point (54) situated lower than said sliding opening, said elastic element carrying or moving one or more marks (55a to 55e) each corresponding to a determined weight (Pla à Pie) of the schoolbag (1), each of said marks being disposed on or with respect to the elastic element at a position determined to be visible above the opening maintaining, under the effect of an elongation of the elastic element (51) caused by the weight of the bag when lifted by said gripping handle (5), if and only if the weight of the binder exceeds the weight (Pic ) corresponding to said mark (55c). 9. Schoolbag (1, ia to ie) according to any one of the preceding claims, characterized in that the casing (10) includes at least one inner wall (14) or outer wall (13) defining a single or multiple compartment said former (101, respectively 104) which is adjacent to the lower bottom (12) and the back panel (11) of said casing, and is arranged to have a rectangular parallelepiped shape of a thickness (E101, E102, E104) lower at its height (H101, H104) and its width (L104), and of dimensions determined to accommodate one or more books and / or notebooks. 10. Satchel (1, ia-ie) according to the preceding claim, characterized in that the front compartment (101, 102, 104) has a thickness (E101, E102, E104) determined to be able to receive a limited thickness of books and or notebooks (81), which thickness is calculated to represent a determined maximum weight. 20 Binder (1, ia) according to any one of the preceding claims, characterized in that the envelope (10) includes one or more internal walls (15) which delimit on the one hand a so-called anterior compartment (101, 104 ) which is located at the bottom of said envelope and adjacent to the back panel and the bottom panel (12), and whose width dimensions (L101, L104) and height (H101, H104) are determined to accommodate one or more books or notebook (81), and secondly one or more so-called complementary compartments (103) located behind and / or above said at least one front compartment (101, 104) and having dimensions (H103, E103) determined so that none of them can accommodate a book or even a notebook. Binder (lb-ie) according to any one of the preceding claims, characterized in that the at least one ventral holding belt (3) is formed in two half-belts (31, 32) joined together at the belly of the carrier (9) by detachable fast-acting fastening means (33), and in that each half-belt (31, 32) is further secured to the side of the belly fastener (33). , at the side ramp (21, respectively 22) corresponding thereto. 13. Schoolbag (lb, ld, le) according to the preceding claim, characterized in that the side straps (21, 22) are fixed on the half-belts (31, respectively 32) by detachable fastening means fast maneuvering (213, 223). 14. Schoolbag (1e) according to any one of the preceding claims, characterized in that it further comprises an additional pocket (6) independent of the envelope (10) of said binder and which is fixed on the shoulder straps (21). 22) and / or the ventral holding belt (3, 31, 32) on the front of the carrier (9) by means of fast-acting detachable fastening means (61). 20 15. Schoolbag (lb to le) according to any one of claims 12 to 14, characterized in that the lower anchorage of the side straps (21, 22) is formed by the anchoring points (311 to 312, respectively 321 322) of the ventral holding belt (3, 31, 32).