Abstract:
The invention relates to An anchoring device that is intended for, for example, the roof of a building. The inventive device comprises: a base which is used to fix to roofing; a hook element which is mounted to the base at one end thereof and which comprises a hook ring at the other end; a tilting mechanism which, in the event of an impact, enables the hook element to tilt in a normal plane in relation to the plane of extension of the base; a damping mechanism which is used to absorb energy during the tilting of the hook element. The damping mechanism comprises a trigger mechanism that can be used to prevent the hook element from tilting when the element is subjected to a force having an intensity that is lower than a pre-determined threshold. The aforementioned trigger mechanism comprises a removable part which is different from the other elements making up the damping mechanism.

Description:
BACKGROUND OF THE INVENTION 
   This application is a 371 of PCT/FR02/03454, filed Oct. 10, 2002 
   The present invention relates to the field of anchoring safety, for example for people working high up on roofs of buildings or on other structures. 
   To ensure the safety of individuals, in particular those working on roofs, the worker is provided with a harness and a tie that he connects to an anchoring device. In the event of a fall, it is this anchoring device, fastened to a receiving structure, for example the roof, which checks the fall. 
   Such an anchoring device must be able to limit the height of a person&#39;s fall as far as possible and induce a minimum amount of force on the receiving structure. 
   In certain cases, the receiving structure does not have sufficient strength to withstand large forces, such as during a fall, for example. It is therefore essential in those cases for the anchoring device to have an energy-absorbing capability, operating as it were as a shock absorber. 
   It is also necessary, when the anchoring device is being fastened to the receiving structure, for example a roof, to ensure that said roof is sealed. This problem arises in particular in the case of anchoring devices fastened directly to the framework and passing through the roof covering. The fact that the sealing function of the roof covering has to be restored after the anchoring device has been installed obviously adds significantly to the cost of the work undertaken. 
   Fastening anchoring devices directly to the roof covering presents not only problems of resistance to forces but also problems connected with variable forms of the roof coverings. 
   Known anchoring devices often have shock-absorbing means which need to be calibrated so that they can withstand a shock or a pull whose intensity is above a certain threshold. 
   Developing such anchoring devices is very difficult and requires a high number of tests for each intended use. It is thus necessary to ensure that the shock-absorbing means do not activate when subjected to a stress below a predetermined intensity on the one hand and that this adjustment does not negatively affect the level of absorption on the other hand. 
   It may be difficult to be able to reconcile the parameters and the tests do not generally allow verification to be carried out without irreversibly damaging the anchoring device. 
   The term “roof covering” is intended to mean any roof covering, and in particular corrugated steel sheeting, for example with a trapezoidal profile. 
   SUMMARY OF THE INVENTION 
   The aim of the present invention is to produce an anchoring device whose reliability may be verified without extra cost and which, where appropriate, may be reused with a minimum amount of repair either for additional tests or for fastening to a roof. 
   Another aim of the present invention is directed toward adjusting the dynamic behavior of the anchoring device to suit a specific use and/or specific constraints. 
   Another aim of the present invention is to produce an anchoring device whose reliability in terms of fastening or whose use is not compromised when the profile of the roof covering changes. 
   An additional aim of the present invention is directed toward providing anchoring safety in spite of a roof covering on which the anchoring device is fastened having a low resistance to forces. 
   According to the invention, the anchoring device intended to equip, for example, the roof of a building, comprises:
         a base combined with fastening means for fastening it to a roof covering,   a hitching element mounted on the base and comprising a hitching ring at its end remote from the base,   tilting means allowing the hitching element to tilt in the event of shock in a plane that is normal to the extension plane of the base,   shock-absorbing means allowing energy to be absorbed during the tilting of the hitching element,   said shock-absorbing means comprising a triggering means for preventing any tilting of the hitching element when the latter is subjected to a force whose intensity is below a predetermined threshold, said triggering means being a removable component separate from the other elements constituting the shock-absorbing means.       

   According to one exemplary embodiment of the anchoring device according to the invention, the shock-absorbing means comprise elements that slide with friction. 
   According to one exemplary embodiment, the triggering means is a deformable component whose resistance to deformation determines the predetermined triggering threshold. 
   According to one exemplary embodiment, the anchoring device comprises:
         a threaded rod articulated on the base with one of its ends, the other end extending inside a tubular body, passing through an opening made in a first end of the tubular body,   a sleeve whose upper face has an opening through which a stub of the hitching ring passes, said stub likewise passing through the second end of said tubular body so as to grip said upper face of the sleeve, the lower end of said sleeve being open and bearing with its edge on the base,   means for mounting the triggering means approximately at the end of the threaded rod extending inside the tubular body,   and peripheral supports for the triggering means that are secured to the tubular body and oppose the movement of said triggering means in the event of the hitching ring being stressed.       

   According to one exemplary embodiment, the peripheral supports are produced with the edge of a friction tube inserted in the tubular body, said friction tube bearing with its opposite edge on the inner face of the first end of the tubular body. 
   According to one exemplary embodiment, the triggering means is a deformable washer. 
   According to one exemplary embodiment, the means for mounting the washer comprise a sliding guide, a conical component, an O-ring seal and a nut, which are mounted on the threaded rod. 
   According to one exemplary embodiment, the base comprises means for adjusting the spacing between the fastening means. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages will also emerge from the detailed description given below, with reference to the appended drawings, by way of nonlimiting examples, in which drawings: 
       FIGS. 1 and 2  are schematic views of the anchoring device according to the invention in two different situations, 
       FIG. 3  is a section of the anchoring device according to the invention, in the vertical position, 
       FIG. 4  is an enlarged detail of  FIG. 3 , 
       FIG. 5  is a section of the anchoring device subjected to a force F, 
       FIG. 6  is an enlarged detail of  FIG. 5 , 
       FIG. 7  is a section of the anchoring device according to the invention, in the tilted position, 
       FIGS. 8 and 9  show another exemplary embodiment of the base of the device according to the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows an exemplary embodiment of an anchoring device  1  according to the invention. 
   The anchoring device  1  comprises a hitching element  2  surmounted by a hitching ring  3 . 
   The anchoring device  1  also comprises a base  4  intended to be fastened to a roof covering  5 . Means for mounting the hitching element  2  on the base  4  are also provided. 
   The base  4  is intended to be fastened to the roof covering  5  using fastening means  6  of the self-drilling screw type that respectively pass through a supporting end  7  of the base  4  in order to be screwed, for example, into a ridge  8  of the roof covering  5 , as depicted in  FIG. 3 , for example. The base  4  is provided with drilled holes  9  for this purpose. These are made in the supporting end  7  of the base  4 , for example. 
   The base  4  is made up of two partially superimposed parts  4   a ,  4   b  that are able to slide relative to one another for adjustment purposes. Each of the parts  4   a ,  4   b  is provided with an oblong hole  10 ,  11  made approximately in the central part and oriented so that the holes overlap one another over at least part of their length. Thus, when the parts  4   a ,  4   b  are adjusted by sliding, the oblong holes  10  and  11  remain at least partially superimposed. 
   The anchoring device  1  also comprises clamping means passing through the overlapping oblong holes  10  and  11 , so as to allow the two parts  4   a ,  4   b  forming the base  4  to be secured with the hitching element  2 . 
   This element comprises a sleeve  12  in which clamping means are at least partly integrated. These clamping means are formed by the means for mounting the hitching element  2  on the base  4 . 
   The anchoring device  1  also comprises means enabling it to tilt the hitching element  2  in a plane that is normal to the extension plane of the base  4 , specifically when said hitching element  2  is subjected to stress. 
     FIG. 2  thus depicts the hitching element  2  in a tilted position, for example following the application of stress or a strong pull on the hitching ring  3 . The hitching element  2  is thus tilted through an angle I so that the orientation of its longitudinal axis J approaches as far as possible an axis contained in the extension plane of the base  4 . A strong pull on the hitching ring  3  in the tilted position ( FIG. 2 ) will thus lead to shear forces on the fastening means  6  for the base  4 . The pulling or wrenching forces will thus be substantially reduced. This is perfectly compatible with a roof covering  5  of lesser strength, which may have a relatively small thickness. 
   The anchoring device  1  comprises, for example, energy-absorbing or shock-absorbing means that are activated when the hitching element  2  tilts relative to the base  4 . These energy-absorbing means are integrated into the sleeve  12 , for example. 
   The base  4  comprises means for adjusting the spacing between the fastening means  6 . The adjustment means are produced with the base  4  in two parts  4   a ,  4   b  that are able to slide relative to one another, with the oblong holes  10  and  11  that overlap one another over at least part of their length, and with clamping means. These clamping means comprise clamping plates  13  and  14  intended to grip the superimposed base parts  4   a ,  4   b.    
   A connecting piece  15  of the yoke type approximately in the shape of an inverted U thus passes through the clamping plate  14 , the oblong holes  10  and  11  and the clamping plate  13 , respectively, and is provided with a locknut  16  on each of its branches  15   a . The locknuts  16  are thus situated under the base  4 . 
   The anchoring device  1  also comprises a threaded rod  17  articulated on the base  4  with one of its ends, more precisely on the connecting piece  15 , the other end extending inside a tubular body  18 . For this purpose, the threaded rod  17  passes through an opening made in a first end  18   a  of said tubular body  18 . 
   The upper end  12   a  of the sleeve  12  has an opening through which a stub  3   a  of the hitching ring  3  passes. This stub also passes through the second end  18   b  of the tubular body  18  so as to grip said upper end  12   a  of the sleeve  12 . The lower end of the sleeve  12  is open and bears, with its edge, on the base  4  and, more precisely, on the clamping plate  14 . 
   According to the invention, the shock-absorbing means are integrated in the sleeve  12 , for example. The shock-absorbing means comprise a triggering means for preventing any tilting of the hitching element  2  when the latter is subjected to a force whose intensity is below a predetermined threshold. The triggering means is a removable component and separate from the other elements constituting the shock-absorbing means. This component may thus be replaced independently of the other elements constituting the shock-absorbing means or the anchoring device  1 . 
   To this end, the anchoring device  1  comprises means for mounting the triggering means approximately at the end of the threaded rod  17  extending inside the tubular body  18 . The latter advantageously has peripheral supports for the triggering means that are secured to said tubular body  18  and oppose the movement of said triggering means in the event of the hitching ring  3  being stressed. 
   The triggering means is preferably a component whose resistance to deformation determines the predetermined triggering threshold and therefore the start of the shock absorption. The peripheral supports in the tubular body  18  are produced with an edge  19  of a friction tube  20  inserted in the tubular body  18 . The friction tube  20  bears with its opposite edge on the inner face  18   c  of the first end  18   a  of the tubular body  18 . 
   The triggering means is produced by a deformable washer  21 . To this end, the anchoring device  1  comprises means for mounting the deformable washer  21  that comprise a sliding guide  22 , a conical component  23 , an O-ring seal  24  and a retaining nut  25 , all mounted on the threaded rod  17  as shown in  FIG. 4 . 
   The sliding guide  22  is intended to center the threaded rod  17  in the friction tube  20  during the tilting of the hitching element  2 , leading to the deformed washer  21  sliding with friction in said friction tube  20 . 
   The sliding guide  22  is kept in position by virtue of the O-ring seal  24  and the conical component  23 , which component also immobilizes the washer  21  on the upper edge of the friction tube  20 , the whole also being in position by virtue of the tightening of the nut  25  at the end of the threaded rod  17 . The sliding with friction of the deformed washer  21  in the friction tube  20  makes it possible to absorb energy during the tilting of the hitching element  2 . The shock-absorbing means comprise elements that slide with friction and the washer  21  makes it possible to produce a triggering means for preventing any tilting of the hitching element  2  when the latter is not sufficiently stressed. 
   A stressing force on the hitching ring  3  is illustrated by the arrow F in  FIG. 5 . A sufficient intensity of such a force F, corresponding for example to a person falling from a roof, leads to deformation of the washer  21  and uniform peripheral friction in the friction tube  20 . The relative tension exerted between the friction tube  20  and the threaded rod  17  is represented by the arrow T in  FIG. 6 . The conical component  23  thus drives the washer  21  into the friction tube  20  as soon as the tension T has reached an intensity above that corresponding to the deformation threshold for said washer  21 . 
   During the tilting of the hitching element  2 , it is the sleeve  12  that bears on the base  4  and causes the deformed washer  21  to slide in the friction tube. The relative tensile force between the friction tube  20  secured to the tubular body  18  and the threaded rod  17  thus makes it possible to absorb the fall of a person during the tilting of said hitching element  2 . 
   The travel of the deformable washer  21  in the friction tube  20  is limited by the sliding guide  22  arriving at and butting against the inner face  18   c  of the first end  18   a  of the tubular body  18 . This end of travel also corresponds to a longitudinal axis J of the hitching element  2 , inclined as far as possible and approaching an inclination of 90° relative to a normal N of the extension plane of the base  4 . The force F thus symbolizes the weight of a person who has suffered a fall, as is depicted in  FIG. 7 . The force F is thus transmitted to the fastening means  6  mainly in the form of shear force. The risk of wrenching to which the fastening means  6  fitted into ridges  8 , for example self-drilling screws, are exposed is therefore significantly reduced. 
   The clamping means of the hitching element  2  are obtained with the stub  3   a  being screwed into a clamping nut  3   b  with the rotation of the hitching ring  3  and thus gripping the second end  18   b  of the tubular body  18  and the upper face  12   a  of the sleeve  12 . The dimensions of the sleeve  12  and of the tubular body  18  are selected so as to obtain optimum clamping of the washer  21  on the edge  19  of the friction tube  20  when the hitching element  2  is in the vertical position. Clamping is obtained by the rotation of the hitching ring  3 , the articulation of the threaded rod  17  on the base  4  and the bearing of the sleeve  12  on said base  4 . 
   As a variant, the nut  3   b  may be replaced by a tapped hole in the upper face  12   a  of the sleeve  12 . 
   In the exemplary embodiment depicted in  FIGS. 8 and 9 , the base  4  comprises two arms  40   a ,  40   b  that are superimposed in their central part. Drilled holes  40   c  provided at each end of the arms  40   a ,  40   b  are intended to have self-drilling screws passing through them, for example. 
   The arms  40   a ,  40   b  are able to pivot relative to one another for adjustment purposes. 
   To this end, oblong slots  41 ,  42  are made in each arm  40   a ,  40   b , approximately in the central position. The oblong slots  41 ,  42  in the arm  40   a  thus at least partially overlap the oblong slots in the other arm  40   b . The extent of such an overlap depends on the relative pivoting of the two arms  40   a ,  40   b.    
   The clamping means, comprising for example the yoke  15 , pass through the superimposed oblong slots  41 ,  42  in the two arms  40   a ,  40   b  and thus allow the two arms  40   a ,  40   b  forming the base  4  to be secured with the hitching element  2 . 
   Before clamping, it is also possible, by way of the relative pivoting of the two arms  40   a ,  40   b , to modify the spacing between the drilled holes  40   c , and therefore between the fastening means. 
   It is possible, for example, to pass from a maximum spacing E illustrated in  FIG. 8  to a minimum spacing e illustrated in  FIG. 9 . 
   The base  4  may then be tailored to roof coverings having different spacings between the ridges  8 . 
   One advantage of the anchoring device  1  according to the invention is the possibility of tilting it in any plane normal to the extension plane of the base  4 . 
   Another advantage lies in the ability to tailor the anchoring device  1  to various spacings between the ridges  8 . 
   Another advantage lies in the removability of the washer  21 . This washer may thus be replaced at very little cost. Such a replacement would make it possible to modify the triggering threshold of the shock-absorbing means. 
   Tests that can be reproduced easily are thus obtained, which is not the case with the plastic deformation of a component. Friction, and therefore shock absorption, may be controlled more reliably within the framework of the invention.