Patent Publication Number: US-11040228-B2

Title: Safety harness with a locking part for positively immobilising fastening buckles of a strap closure and adjustment system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of PCT Application No. PCT/FR2018/050260 filed on Feb. 2, 2018, which claims priority to French Patent Application No. 17/50914 filed on Feb. 3, 2017, the contents each of which are incorporated herein by reference thereto. 
     FIELD OF THE DISCLOSURE 
     The present invention concerns a safety harness, comprising at least one strap, at least one attachment member for the tie-in of the safety harness and a system for closing the strap provided with a first fastening buckle secured to a first strand of the strap and a second fastening buckle secured to a second strand of the strap, the second fastening buckle being able to cooperate with the first fastening buckle in a mutual fastening configuration in which the strap is closed on itself to form a closed loop. 
     In a known manner in the field of climbing, mountaineering or for carrying out works at height, a safety harness also known as a «climbing harness», conventionally comprises at least one strap intended to be shaped into a closed loop by means of a closure and adjustment system to adjust the perimeter of the closed loop to the morphology of the user of the harness. 
     BACKGROUND 
     Such a strap is intended to form, in the configuration closed on itself in a closed loop, a tie-in belt intended to be disposed at the waist of the safety user of the harness, a thigh buckle for leg-strap, a buckle under gluteal, a buckle intended for setup on the torso of the user, a sling, etc. . . . 
     This type of safety harness can also be used in the ski field, for canyoning activities, or for speleology. 
     For the tie-in of the safety harness and the securing of the wearer, there is conventionally provided at least one attachment member arranged at the front of the tie-in belt. It may consist of an annular buckle fixedly mounted on the belt or slidably mounted along the belt. 
     The closure system is an essential element for safety and because of the weight it represents compared to the rest of the harness. It should be noted that looking for optimization of the weight of the harness may be a predominant criterion in some fields of use of the harness. Moreover, it is sometimes necessary to enable easy and fast adjustment of the strap in order to make the harness user-friendly in all situations. 
     There is a first family of closure and adjustment system based on the use of one single buckle trapped on the strap and configured to enable the strap to pass through the buckle in one direction at an adjustable location of: the strap and back through the buckle in the opposite direction in order to secure the fixing. While this system, conventionally known as the passing-passing back buckle, is safe and offers the possibility of a full opening (which may be interesting for example at the level of leg buckles), it does not enable quick and easy adjustment. 
     A second family of closure and adjustment system is based on the use of two metal buckles trapped at the same end of the strap, operating on the self-blocking principle and enabling full opening and quick adjustment. Nonetheless, the conferred safety is not optimal and the weight is considerable. 
     A third family of closure and adjustment system is based on the use of a movable fastening buckle occupying an adjustable position along one of the strands of the strap and a fixed fastening buckle mounted without adjustment at the end of the other strand of the strap. 
     A known solution of this third family is to use the buckles known under the common name of «rapco», for example as described in the patent US2807852A, generally by means of respectively two movable and fixed metal attachments, the movable attachment being intended to be superimposed on the fixed attachment in order to create a pinch of the strap strand that passes through the movable fastener. While this system enables a total opening of the strap and a quick adjustment, it does not provide sufficient safety because the attachments are likely to open accidentally when the tension of the strap is not sufficient. This risk is particularly present for the safety harnesses whose attachment member (for the tie-in of the harness and the safety of the wearer of the harness) is movably mounted along the belt because the attachment member thus sliding is likely to lift one of the attachments until authorizing the unlocking thereof. 
     Another solution of the third family is described in the U.S. Pat. No. 5,988,315A but the described harness does not address the problems hereinabove. 
     BRIEF SUMMARY 
     The present invention aims at solving all or part of the drawbacks listed hereinabove. 
     In this context, there is a need to provide a safety harness with a closure system that is lightweight, simple, and economical to manufacture, which enables a full opening of the strap and a possible quick adjustment, while being completely safe and avoiding any risk of accidental opening of the strap. 
     To this end, there is proposed a safety harness, comprising at least one strap, at least one attachment member for the tie-in of the safety harness, and a system for closing the strap provided with a first fastening buckle secured to a first strand of the strap and a second fastening buckle secured to a second strand of the strap, the second fastening buckle being able to cooperate with the first fastening buckle in a mutual fastening configuration in which the strap is closed on itself to form a closed loop. The safety harness comprising a locking part independent of the first and second fastening buckles, and secured to the first strand of the strap or to the second strand of the strap and adapted to vary between a first configuration in which it occupies an active state in which it biases the first and second fastening buckles relative to each other in a manner ensuring a positive blocking of the first and second fastening buckles in the mutual fastening configuration, and a second configuration in which it occupies an inactive state in which the first and second fixed and movable fastening buckles can freely adopt or leave the mutual fastening configuration. 
     The safety harness may implement the advantageous following features, considered separately or in combination. 
     The locking part comprises mechanical elements allowing biasing the first and second fastening buckles relative to each other when they adopt their mutual fastening configuration, by exerting a mechanical tension thereon opposing the relative displacement of the first and second fastening buckles. 
     The first fastening buckle is fixed by being fixedly secured to the first strand of the strap and the second fastening buckle is movable by being adjustably secured to the second strand of the strap so that the closure system enables an adjustment of the strap such that the closed loop formed when the strap is closed on itself in the mutual fastening configuration of the first and second fastening buckles has a perimeter adjustable by adjusting the position occupied by the second fastening buckle relative to the second strand of the strap. 
     The safety harness comprises fixing means ensuring a positive blocking of the locking part in its active state by fixing on at least one of the fastening buckles. 
     The fixing means comprise mechanical snap-fitting elements and/or magnetic elements. 
     The passage of the locking part from the first configuration to the second configuration and vice versa results from a change of position of the locking part relative to the strand of the strap to which the locking part is secured. 
     The locking part is mounted in a sliding manner on the strand of the strap to which it is secured, the change of position of the locking part being performed by sliding along the strand of the strap. 
     In a first embodiment, one of the first and second fastening buckles is in the form of a male buckle made of a rigid material and the other of the first and second fastening buckles is in the form of a female buckle formed as a closed loop made of a flexible material, the male buckle being provided to fit through the female buckle and to be gripped to the female buckle after insertion. 
     The locking part is in the form of a link formed in a flexible and elastically deformable material and arranged in the form of a closed loop whose ends are fastened to the strand of the strap to which the male buckle is secured and/or to the male buckle, said link being adapted, when it adopts the first configuration corresponding to its active state, to trap the female buckle in combination with the male buckle and to exert a mechanical tension on the male and female buckles preventing the male buckle from leaving the female buckle. 
     In a second embodiment, the first and second fastening buckles are constituted respectively by first and second attachments adapted to cooperate with each other, when they adopt mutual fastening configuration, by simple bearing against each other, where the second attachment is superimposed on the first attachment, the first attachment being secured to a free end of the first strand of the strap, the second attachment enabling the second strand of the strap to pass through the second attachment by forming a bend in the form of a simple ring, the first and second attachments causing a pinch of the second strand of the strap at the level of said bend between the first and second attachments, the pinch force increasing with the tension applied on the first and second strands of the strap. 
     In its active state, the locking part biases the first and second attachments so as to exert thereon a mechanical tension opposing the relative displacement between the first and second attachments in a manner ensuring a positive blocking of the pinch of the second strand of the strap between the first and second attachments and preventing the second attachment, in its position superimposed on the first attachment, from passing throughout an opening of the first attachment through which it has passed to occupy said superimposed position. 
     The locking part delimits a slider slidably mounted on the second strand of the strap which is secured to the second attachment and a housing in which a portion of the first attachment and/or of the second attachment, when the first and second attachments adopt the mutual fastening configuration by simple bearing, is adapted to be inserted, the slider and the housing being superimposed so that when said portion of the first attachment and/or of the second attachment is inserted into the housing, the locking part, via the connection between the second attachment and the slider of the locking part formed by the second strand, opposes the lifting of the second attachment bearing on the first attachment. 
     The locking part is equipped with a foolproof system ensuring that the locking part can be placed in its first configuration and in its active state if a first face of the second attachment bears against the first attachment and that the locking part cannot be placed in its first configuration and in its active state if a second face of the second attachment, opposite to said first face, bears against the first attachment. 
     The first and second attachments are permanently secured to each other. 
     The locking part is formed in a rigid material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood using the following description of particular embodiments of the invention provided as non-limiting examples and represented in the appended drawings, in which: 
         FIG. 1  is a general view of a tie-in belt of a first exemplary embodiment of the safety harness according to the invention, apart from the situation of mutual fastening configuration of the two fastening buckles. 
         FIG. 2  is a detail view of the tie-in belt of  FIG. 1  at the level of the fastening buckles, in a situation of mutual fastening configuration of the fastening buckles and active state of the locking part. 
         FIG. 3  shows the two fastening buckles of the tie-in belt of a second exemplary embodiment of the safety harness according to the invention, apart from the situation of mutual fastening configuration of the fastening buckles. 
         FIG. 4  illustrates the two fastening buckles of  FIG. 3  in a situation of mutual fastening configuration and active state of the locking part. 
         FIG. 5  is a longitudinal sectional view of the two fastening buckles of  FIGS. 3 and 4  in a situation of mutual fastening configuration and inactive state of the locking part. 
         FIG. 6  shows the closure system of a third exemplary embodiment of the safety harness according to the invention, the fastening buckles being in a fastening situation and the locking part being in its inactive state. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the appended  FIGS. 1 to 6  as summarily presented hereinabove, the invention essentially concerns a safety harness comprising at least one strap  10 , at least one attachment member (not represented) enabling the tie-in of the safety harness in order to secure the wearer of the harness, and a system for closing the strap  10 . 
     In general, the safety harness is intended to be used in mountaineering, climbing, work at height, canyoning, skiing, or even speleology. 
     The strap  10 , once closed over itself by means of the closure system so as to form a closed loop, is intended to form for example, a tie-in belt (as is the case in the two embodiments represented in  FIGS. 1 to 5 ) intended to be placed at the waist of the user but could equally constitute a thigh buckle, a belt under gluteal, a belt to be used at the level of the torso, a sling, etc. . . . For example, the strap  10  is made of a synthetic fabric, in particular in high density polyethylene, and possibly an upholstery structure such as, for example, a filler foam in certain areas of its length. 
     The attachment member is in particular arranged at the front of the tie-in belt to ensure the tie-in of the belt and therefore of the harness. The attachment member is for example constituted by an annular buckle, formed in a rigid material or in a flexible material, secured to the belt by being fixedly mounted along the latter or conversely by being mounted in a sliding manner along the front portion of the belt. 
     The nature of the strap  10  and that of the attachment member are not per se an important part of the invention. However, the nature of the closure system is an important aspect, and will be the object of a detailed description of two conceivable embodiments, both of which correspond to the same inventive concept which. will. be presented later, in support of three examples, respectively in  FIGS. 1, 3 and 6 . 
     For reasons of simplicity of understanding and reading, elements having a similar function from one embodiment to another will keep the same reference numerals in all  FIGS. 1 to 6 , even if the shape and design of these elements are different from one embodiment to another. 
     In general, the closure system is intended to be able to close the strap  10  on itself in order to form a closed loop, or on the contrary, to be able to completely open the buckle. This may be very interesting, for example, when the strap is intended to constitute a thigh buckle in order to facilitate the clip-in. The closure and the opening of the strap  10  must be very easy and fast, in order to offer optimal user-friendliness to the safety harness. The weight of the closure system must be as large as possible. Finally, the closure system is configured to prevent any inadvertent opening of the closed loop defined by the strap  10 , for safety reasons. 
     In the two embodiments described later on with reference to  FIGS. 1 and 2  and  FIGS. 3 to 6  respectively, the closure system is provided with a first fastening buckle  11  secured to a first strand  101  of the strap  10  and a second fastening buckle  12  secured to a second strand  102  of the strap  10 . The second fastening buckle  12  is adapted to cooperate with the first fastening buckle  11  so as to adopt a mutual fastening configuration in which the strap  10  is closed on itself to form a closed loop. 
     Essentially, the two embodiments respectively of  FIGS. 1 and 2  and  FIGS. 3 to 6  differ from each other as to the nature of the fixed first fastening buckle  11  and of the second fastening buckle  12  and as to the nature of cooperating with each other in the mutual fastening configuration. 
     In addition, in the two embodiments described later on with reference to  FIGS. 1 and 2  and  FIGS. 3 to 6  respectively, the closure system comprises a locking part  13  independent of the first fastening buckle  11  and of the second fastening buckle  12 . The locking pan  13  may be secured to the first strand  101  of the strap  10  to which the first fastening buckle  11  is secured or to the second strand  102  of the strap  10  to which the second fastening buckle  12  is secured. The locking part  13 , thereby captive, is adapted to vary by actuation of the user between a first configuration in which it occupies an active state ( FIG. 2  for the first embodiment illustrated in the first example of  FIGS. 1 and 2 ;  FIG. 4  for the first example of the second embodiment illustrated in  FIGS. 3 to 5 ) in which it biases the first and second fastening buckles  11 ,  12  relative to one another in a manner ensuring a positive blocking of the first and second fastening buckles  11 ,  12  in the mutual fastening configuration, and a second configuration in which it occupies an inactive state ( FIG. 1  for the first embodiment illustrated in the first example of  FIGS. 1 and 2 ;  FIG. 6  for the second example of the second embodiment illustrated in  FIG. 6 ) in which the first and second fastening buckles  11 ,  12  can freely adopt or leave the mutual fastening configuration. 
     Locking pan  13  comprises mechanical elements, which will be detailed later on, allowing biasing the first and second fastening buckles  11 ,  12  relative to each other when these adopt their mutual fastening configuration, by exerting a mechanical tension thereon opposing the relative displacement of the first and second fastening buckles  11 ,  12 . The nature of the mechanical elements thus mentioned and the manner of forming them structurally vary between the first embodiment and the second embodiment, even though the general principle is common to both embodiments. 
     The two embodiments of  FIGS. 1 and 2  and  FIGS. 3 to 6  respectively also differ from each other as to the nature of the locking part  13  and as to the nature of occupying the active state for positive blocking purposes as described above. 
     By positive «blocking in the mutual fastening configuration», it should he herein understood that the mutual fastening configuration is definitely guaranteed by the locking part  13  as long as no action specifically required to place the locking part in its inactive state is applied to the locking part  13  by the wearer of the safety harness. 
     In a non-limiting manner, it is advantageous to provide for the first fastening buckle  11  being fixed by being fixedly secured to the first strand  101  of the strap  10  and the second fastening buckle  12  being movable by being adjustably secured on the second strand  102  of the strap  10  so that the closure system enables an adjustment of the strap  10  such that the closed loop formed when the strap  10  is closed on itself in the mutual fastening configuration of the first and second fastening buckle  11 ,  12  has an adjustable perimeter by adjusting the position occupied by the second fastening buckle  12  relative to the second strand  102  of the strap  10 . Regardless of the concerned embodiment, it remains quite possible to consider that each of the first and second fastening buckles  11 ,  12  is fixed by being fixedly secured to the strand  101 , 102  on which it is mounted. 
     According to a particular embodiment, the safety harness comprises fixing means that provide a positive blocking when the locking part  13  is in its active state by fixing on at least one of the first and second fastening buckles  11 ,  12 . Thus, it is possible to provide for the locking part  13 , when it occupies its active state itself ensuring the positive blocking of the fastening buckles  11 ,  12  in their mutual fastening configuration, being fixed by means of a positive blocking to the first buckle  11  and/or to the second buckle  12  by these fixing means. An example of such fixing means is described below and illustrated in  FIG. 6 . The fixing means may in particular comprise mechanical snap-fitting elements and/or magnetic elements, which is effective, economical, and lightweight. The fixing means may comprise first elements secured to the locking part  13  and complementary second elements secured to the fastening buckle  11 ,  12  to which it is fixed. 
     By «positive blocking in the active state», it should be herein understood that the active state of the locking part  13  is definitely guaranteed by the fixing means as long as no action specifically required to unlock the fixing means is applied to the fixing means by the wearer of the safety harness. 
     The passage of the locking part  13  from the first configuration in which it occupies its active state to the second configuration in which it occupies its inactive state, and vice versa, results from a change of position of the locking pan  13  relative to the strand  101 ,  102  of the strap  10  to which the locking part  13  is secured. In particular, in the second embodiment of  FIGS. 3 to 5 , the locking part  13  is mounted in a sliding manner on the strand  101 ,  102  of the strap  10  to which it is secured, the change of position of the locking part  13  being performed by sliding along this strand  101 ,  102  of the strap  10 . The locking part  13  may be equipped with a sliding guide means provided to this end, shown, for example, in  FIG. 6 . In the case of the first embodiment with reference to  FIGS. 1 and 2 , the change of position of the locking part  13  to pass from the active state to the inactive state and vice versa is performed by a tilting of the locking part  13  relative to the strand to which it is secured. 
     Referring now more specifically to the first embodiment of  FIGS. 1 and 2 , one of the first and second fastening buckles  11 ,  12  is in the form of a male buckle made of a rigid material and the other of the first and second fastening buckles  11 ,  12  is in the form of a female buckle formed as a closed loop made of a flexible material, the male buckle being provided to fit through the female buckle and to be gripped by the female buckle after insertion. 
     In the illustrated example, the male buckle is in the form of a plastic part provided with two lateral projections  14   a ,  14   b  for gripping to the female buckle which is made herein by a closed loop  15  made of a flexible synthetic material. 
     For example, the male buckle acts as a movable fastening buckle whereas the female buckle in the form of a closed loop  15  constitutes a fixed fastening buckle, even though an inverted arrangement may be considered depending, on the design of the strap  10 . Still alternatively, the two male and female buckles may constitute two tried fastening buckles  11 ,  12  in the ease where the closure system is not intended to enable a perimeter adjustment. 
     Moreover, in the first embodiment of  FIGS. 1 and 2 , the locking part  13  is in the form of a link  16  formed in a flexible and elastically deformable material and arranged in the form of a closed loop. In the figures, the ends of this link  16  are fastened to the strand  101 ,  102  of the strap  10  to which the male buckle is secured. Alternatively or in combination, in a non-represented manner, the two ends of the link  16  could be fastened directly to the male buckle, typically at the level of the two lateral projections  14   a ,  14   b  respectively. The link  16  is configured to trap the female buckle, when the link  16  adopts the first configuration corresponding to its active state, in combination with the male buckle and to exert a mechanical tension on the male and female buckles preventing the male buckle from leaving the female buckle. In the represented example, the link  16  is constituted in the form of two strands knotted together at their distal ends whereas their proximal ends are secured to the strand  102  of the strap  10 . 
     In order to pass the link  16  constituting the locking pat  13  in the active state, all it needs, once the male buckle is in a mutual fastening position with the female buckle (this being previously obtained by insertion of the male buckle throughout the closed loop  15  until gripping of the lateral projections  14   a ,  14   b  on the closed loop  15 ), is to displace the link  16  by tilting relative to the strand of the strap  10  whose link is secured so as to make the male buckle pass through the link  16  until gripping of the lateral projections  14   a ,  14   b  on the link  16 . The link  16  then traps the closed loop  15  in combination with the part constituting the male buckle and, at least by its elasticity, exerts a mechanical tension on the male buckle and on the closed loop  15  preventing any disengagement of the male buckle from the closed loop  15  as long as the link  16  is in place. Hence, a positive blocking is obtained because it will be maintained as long as the link  16  is not specifically removed from the lateral projections  14   a ,  14   b  by a reverse tilting, regardless of the tension exerted on the strands  101 ,  102  of the strap  10 . 
     It is therefore herein understood that the mechanical elements provide a biasing of the first and second fastening buckles  11 ,  12  relative to one another when these adopt their mutual fastening configuration, by exerting a mechanical tension thereon opposed to the relative displacement of the first and second fastening buckles  11 ,  12 . The biasing is obtained by the link  16  in a closed loop by its ability to enclose the female buckle in combination with the male buckle and by a length of the link  16  adapted so that when it traps the female buckle, the link is elastically deformed in order to exert reciprocally the mechanical tension that biases the male and female buckles in the manner ensuring their positive blocking in the mutual fastening configuration. 
     Referring now more specifically to the second embodiment of  FIGS. 3 to 6 , the first and second fastening buckles  11 ,  12  are constituted respectively by first and second attachments adapted to cooperate with each other, when these adopt the mutual fastening configuration ( FIGS. 4 to 6 ) by simple bearing against each other where the second attachment is in a position superimposed on the first attachment. For example, the first and second attachments are generally in the form of metal plates generally planar and perforated at their center so as to delimit a respective central opening. The second attachment is intended to bear against an upper face  23  or the first attachment. The first attachment is secured, for example fixedly secured, to a free end of the first strand  101  of the strap  10 , typically by being trapped in a loop closed on itself formed at the free end of the first strand  101  of the strap  10 . The second attachment enables the second strand  1 . 02  of the strap  10  to pass through the second attachment, at the level of its central opening, forming a bend  17  in the form of a simple ring. The position of the second attachment is for example adjustable along the second strand  102  by sliding more or less the second attachment along the second strand  102 . The first attachment and the second attachment cause a pinch  18  of the second strand  102  of the strap  10  at the level of the bend  17  between the first and second attachments. The force of this pinch  18  increases concomitantly with the tension applied on. the first and second strands  101 ,  102  of the strap  10 . 
     In a variant as represented in  FIGS. 3 to 6  but not limited thereto, the second attachment is adapted to pass through the opening  22  delimited by the first attachment to adopt the mutual fastening configuration. In this variant, the locking part  13  advantageously allows, besides ensuring the positive blocking of the pinch  18  of the second strand  102  at the level of the bend  17  formed through the second attachment, to prevent the second attachment, in its position superimposed on the first attachment, to pass throughout the opening  22  of the first attachment even though the tension applied to the strap  10  becomes weak. 
     In other words, in the second embodiment, the kicking pan  13  biases in its active state the first and second attachments so as to exert thereon a mechanical tension opposing the relative displacement between the first and second attachments. This mechanical tension exerted by the locking part  13  on the one hand ensures a positive blocking of the pinch  18  of the second strand  102  of the strap  10  between the first and second attachments and on the other hand prevents the second attachment, in its position superimposed on the first attachment ( FIGS. 4 to 6 ), from passing through the central opening  22  of the first attachment through which it has previously passed to occupy said superimposed position. This positive blocking is present independently of the tension exerted on the strands  101 ,  102  of the strap  10 . 
     In  FIG. 3 , the two attachments are not yet in the mutual fastening configuration. In order to occupy this configuration, it is necessary to pass the second attachment, having been previously mounted on the second strand  102  of the strap  10  by forming the bend  17 , through the opening  22  of the first attachment and to bear the second attachment on the upper face  23  of the first attachment. This leads to the configuration shown in  FIG. 5 , the pinch  18  being present. It should be noted that this pinch  18  occurs and in a self-blocking manner only if the second attachment simply bears on the first attachment by its first face  19  whereas this pinch  18  does not occur if the second attachment bears against the first attachment by its second face  20  opposite to the first face  19  in the direction of the thickness of the second attachment. 
     Therefore, according to a non-limiting embodiment, the locking part  13  is equipped with a foolproof system ensuring that the locking part  13  can be placed in its first configuration and in its active state if the first face  19  of the second attachment bears against the first attachment and ensuring that the locking part  13  cannot be placed in its first configuration and in its active state if the second face  20  of the second attachment bears against the first attachment. 
     In  FIG. 4 , the reference  21  represents the position occupied by the locking part  13  when it is in its first configuration and, therefore, it occupies its active state. The reference  21 ′ represents the position occupied by the locking part  13  when it is in its second configuration and, therefore, it occupies its inactive state, assuming that the locking part  13  would be secured, typically by being mounted in a sliding manner, to the second strand  102  of the strap  10  to which the second fastening buckle  12  is also secured. Finally, the reference  21 ″ represents the position occupied by the locking part  13  when it is in its second configuration and, therefore, it occupies its inactive state, assuming that the locking part  13  would be secured, typically by being mounted in a sliding manner, to the first strand  101  of the strap  10  to which the first fastening buckle  11  is also secured. 
     In a variant which is not represented, the first and second attachments are secured to one another permanently, in particular by being pivotally mounted relative to each other. 
       FIG. 6  illustrates, in the form of a second exemplary embodiment, another possible variant of the second embodiment of a safety harness according to the invention. Thus, in this example with reference to  FIG. 6 , the closure system comprises, as in the case of  FIG. 3 , a first attachment which constitutes the first fastening buckle, a second attachment which constitutes the second fastening buckle  12  and a locking part  13 . The locking part  13  delimits a slider  26  mounted in a sliding manner on the second strand  102  of the strap  10  to which the second attachment is secured and a housing  25  in which a portion of the second attachment, when the first and second. attachments adopt the mutual fastening configuration by simply bearing on each other, is adapted to be inserted. The slider  26  and the housing  25  are superimposed transversely to the direction in which the second strand  102  extends and. are delimited by the locking part  13 , the slider and housing being integrally formed in. a rigid material such as for example a steel or a plastic. At the level of the second attachment, the strap  10  forms a bend  1 . 7  in the same manner as was described for the first example represented in  FIGS. 3 to 5 , The first attachment and the second attachment cause a pinch. of the second strand  102  of the strap  10  at the level of the bend  17  between the first and second attachments. The force of this pinch increases concomitantly with the tension applied on the first and second strands  101 ,  102  of the strap  10 . In its active state which results from the insertion of the corresponding portion of the second attachment into the housing  25 , the locking part  13  biases the first and second attachments so as to exert thereon a mechanical tension opposing the relative displacement between the first and second attachments. This mechanical tension exerted by the locking part  13  on the one hand ensures the positive blocking of the pinch of the second strand  102  of the strap  10  between the first and second attachments and on the other hand prevents the second attachment, in its position superimposed on the first attachment, from passing throughout the central opening  22  of the first attachment through which it has previously passed to occupy said superimposed position. This positive blocking is present regardless of the tension exerted on the strands  101 ,  102  of the strap  10 . The arrangement of the slider  26  and the housing  25  as thus described and illustrated allows in practice, when the portion of the second attachment is inserted in the housing  25 , the locking part  13 , via the connection between the second attachment and the slider  26  of the locking part  13  to be concretely formed by the second strand  102 , and opposes the lifting the second attachment from the first attachment. By blocking any possibility of the second attachment lifting relative to the first attachment, thanks to the mechanical tension exerted by the locking part  13  via the strand  102  of the strap  10 , the locking part  13  ensures, when in the active state, the positive blocking of the two attachments in their mutual fastening configuration. 
     As already described, the slider  26  allows for the change of state of the locking part to be performed by a sliding position change of the locking part along the strand  102  of the strap  10 . 
     It is herein specified that the housing  25  may be provided to receive, in addition to the portion of the second attachment which is inserted therein or in substitution, a portion of the first attachment. The previously described operation would be identical. 
     The safety harness represented in  FIG. 6  has the advantage of comprising fixing means previously mentioned, that provide the positive blocking of the locking part  13  in its active state by fixing on the second attachment. Thus, the locking part  13 , when it occupies its active state itself ensuring the positive blocking of the fastening buckles  11 ,  12  in their mutual fastening configuration, is fixed by means of a positive blocking to the second attachment by these fixing means. These fixing means comprise first mechanical snap-hitting elements  24   b  secured to the locking part  13  and complementary second mechanical snap-fitting elements  24   a  secured to the second attachment to which it is fixed. 
     It is therefore herein understood that, in the second embodiment as represented with the example of  FIG. 6 , the mechanical elements provide a biasing of the first and second fastening buckles  11 ,  12  relative to one another when the fastening buckles are in the mutual fastening configuration, by exerting a mechanical tension thereon that opposes the relative displacement of the first and second fastening buckles  11 ,  12 . The slider  26  and housing  25  are adapted to receive a portion of the first attachment and/or a portion of the second attachment, and may also include fixing means  24   a ,  24   b,    
     The two embodiments described in this document correspond to the same inventive concept and the locking part  13  in both cases corresponds to the same general principles, in particular as regards the mechanical elements that it comprises, even though the structural means for filling its function are different from one embodiment to another. 
     The safety harness that has just been described has the advantage of being light, simple and economical to manufacture, of enabling a full opening of the strap and a quick adjustment, and of enabling a completely safe harness, by avoiding any risk of accidental opening of the strap  10 . 
     Of course, the invention is not limited to the embodiments represented and described hereinabove, but covers all variants thereof.