Abstract:
A method and an implementation equipment for fixing an elastic clamp band ( 1 ) to the lugs ( 5 ) particularly adapted for re-current mounting of a flexible connection pipe ( 12 ) on a pipe system ( 13 ). An automatic dispenser ( 2 ) of clamp bands ( 1 ) is arranged to position each clamp band ( 1 ) such that its two lugs are externally accessible to be seized by the grips ( 9, 52, 103 ) of a hand tool for extracting and fixing ( 8, 50, 100 ) which are brought together to compress the lugs ( 5 ) of the clamp band ( 1 ) by external ( 11 ) separately controlled actuators. The tool ( 8, 50, 100 ) comprises elements for bringing together the grips ( 9, 52, 103 )) freely and reversibly when the external actuators ( 11 ) are activated and elements for releasing them instantly or gradually at the desired moment with an external control ( 14, 123 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a process for applying resilient clamping bands with lugs, particularly adapted to assembly lines for products such as flexible pipes particularly in the automotive field; the invention also relates to the tools for practicing the process. 
     The invention relates to clamping bands which are conventionally produced from a strip of sheet metal shaped as a generally circular ring. The ring in question is adapted to be deformed by spacing its two ends which creates a resilient return couple used for gripping; among these types of clamping bands are of particular interest those whose two ends of the spring band overlap; an intermediate cutout of the clamping band extends for several centimeters at one of its ends to form a passage for the other, which is decreased in width to coincide with said passage. The two ends of the band are provided with a drive lug obtained by simple right angle bending of its external portions outwardly of the band such that, thanks to a plier having jaws, the two control lugs can easily be brought together, which is to say to increase the diameter of the clamping band which produces, when released, the resilient return couple necessary for gripping, for example of a flexible pipe on a pipe system. 
     DESCRIPTION OF THE RELATED ART 
     There exist numerous tools for mounting and unmounting such clamping bands, but they are very generally manually operated and independent; these tools must be of small size and particularly light in weight to fulfill effectively the speed required for present production lines. 
     Other problems also arise for these tools, which require the user to exert, for each mounted resilient clamping band, the force necessary at least for their expansion, even if they use lever systems greatly facilitating this operation, as is for example taught by French patent FR-96/16083. 
     SUMMARY OF THE INVENTION 
     It will accordingly be evident that it would be advantageous to have a mechanized device permitting instead to permit the user to pre-stress the resilient clamping bands before emplacement, without at the same time losing the advantage of small size of a strictly manual and independent application tool permitting rapid and precise positioning in an environment with very limited accessibility. 
     To this end, and according to the present invention, there is proposed for applying resilient clamping bands with lugs, particularly adapted to repeated mounting of flexible pipes on a pipe system, a process that it remarkable in that from a clamping band dispenser associated with a hand tool that is autonomous, forming the assembly of the tool for applying resilient bands, said tool being conventionally provided with two jaws shaped for gripping and bringing together the lugs of a clamping band to open it, the following successive steps being taken: 
     a) emplacing the jaws of the tool on the lugs of a first clamping band suitably positioned in the dispenser, 
     b) pre-locking the jaws of the tool bearing on the ears of said clamping band bringing it into the opening position thanks to mechanized actuation means, 
     c) self-holding the jaws in the pre-locking position thanks to internal means of the tool, 
     d) withdrawing from the dispenser said first clamping band held open by the hand tool and the correct automatic positioning of a second clamping band ready for a second extraction, 
     e) positioning the opened clamping band about the flexible pipe, 
     f) releasing the locking of the jaws of the tool which is provided for this purpose with control means to close the clamping band on the flexible pipe, and to cause its clamping on the pipe system, and releasing the tool for a new operation. 
     It will be easily understood that it is very interesting to have such a process that does not require the user to exert the energy necessary to pre-stress the resilient clamping bands before positioning on the piping, which instead is performed by an external device which can be automatically or manually controlled by the operator himself. 
     According to a preferred characteristic, the operation of pre-stressing the clamping bands taking place within the dispenser, the dangers of untimely ejection and breakage are eliminated, that are now observed with conventional hand tools at the time of insertion of the clamping bands between their jaws. 
     According to another object of the invention, there is provided a hand tool for extraction and positioning that is particularly adapted for use in the process described above. According to a first modification, such a tool comprises two confronting jaws, shaped to receive the lugs of a resilient clamping band and disposed at the end of two articulated legs to be disposed in a V shape so as to coact with the clamping band dispenser in a fixed position provided with its pre-compression system as has been mentioned; in this modification, the positioning tool is provided with a blocking system permitting freely and automatically the operation of the mechanism for bringing the jaws together to stress a clamping band and, on the contrary, preventing the reverse movement except when actuated by a control provided for this purpose to space apart automatically the movable jaws. According to this first modification, the release device for the jaws which will be described in greater detail hereafter, has no progressivity such that the positioning of the clamping band is extremely quick, which can lead in certain situations to a loss of precision in its positioning on the clamping zone. This is the reason why there are also provided two other modifications of the positioning tool that can use the process according to the invention, which permit a more progressive release of the jaws at the time of mounting the clamping band on the flexible pipes. 
     Thus, according to other modifications of the positioning tool, the latter comprises two legs provided, at one of their ends, with jaws and an articulation at the other to open freely under the action of the stress in the clamping band from a position in which they are close to each other or the jaws hold the compression of the clamping band, to a deployed position in a V configuration permitting the jaws to engage or disengage the lugs of the clamping band when the latter is respectively ready in the fixed dispenser, or discharge after its emplacement on the flexible pipe, coacting with means such that, when said legs are mounted slidably along their articulated ends in the direction of their longitudinal axis within and into abutment with a bottom of a casing, only the jaws emerge from the opening of said casing with which the legs coact to be held in closed position and stabilized by braking means; and conversely, when said legs are progressively slid outwardly under the controlled action of the force of the clamping band to a stop abutment near the opening of the casing, they deploy into a V configuration thanks to a resilient member acting against both of them. 
     The great advantage provided by these new modifications of the emplacement tool will be understood, in which the release of the jaws takes place in a progressive manner, or, according to a second modification, by a controlled retraction of the tool permitting progressive opening of the two arms and hence the release of the clamping band which, moreover, is necessarily in rear abutment against the passage to resist the retraction force (which prevents any lateral shift of the clamping band along the flexible pipe at the time of its mounting), or in a third modification by using preferably the external edges of the legs of said tool, which are used as a smooth track or partially bent to provide under the force of a compressed clamping band, respectively a free guiding and sliding on one leg and a free guiding or braking on the other leg by the bias of a regulation mechanism controlled such that the assembly of the two legs, beginning from their innermost position in abutment against the rear, wherein the clamping band is totally compressed, deploy progressively outwardly under the gradual and controlled action of said mechanism. 
     On the other hand, given that the position of a clamping band on piping takes place most of the time under cramped conditions (vehicle assembly line), it has to be taken into account that to mount a clamping band on a flexible pipe, there is seldom sufficient space to carry out an inclined or even perpendicular retraction relative to the piping, that would be necessary correctly to use the positioning tool. 
     To overcome this great drawback that can be encountered with the first two modifications, it has been proposed according to an essential characteristic of the third modification, to mount on the legs of the tool rotatable jaws so as to be able at least to incline the tool at the time of its retraction to release the clamping bands; it follows that such a situation cannot be controlled other than by the gradual control of the extension of the legs thanks to the release mechanism provided in the third embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages will become better apparent from the description of a tool for practicing the process according to the invention, given by way of non-limiting example of the invention, with reference to the drawings, in which: 
     FIGS. 1 to  4  show schematically the four principal steps of the process for positioning a resilient clamping band for securement of a flexible pipe on piping from a clamping band dispenser, 
     FIGS. 5 and 6 are partial schematic views, in elevation (FIG.  5 ), and from above (FIG.  6 ), of the loading system and pre-gripping of a manual emplacement tool, from the clamping band dispenser, 
     FIG. 7 shows, in a view from above and in medial cross-section, the kinematics of the principal elements constituting the first embodiment of the manual tool for extracting and positioning resilient clamping bands, between a rest position in full line and a position of extraction of the clamping bands in broken lines, 
     FIG. 8 corresponds to a cross-section on the line VIII—VIII of FIG. 7, showing the kinematics of the pieces in a plan perpendicular to that of FIG. 7, 
     FIGS. 9 and 10 show in medial transverse cross-section, respectively from the side (FIG. 9) and from above (FIG.  10 ), an extraction and positioning tool according to the invention, according to this first embodiment, 
     FIG. 11 is a cross-sectional view on the line XI—XI of FIG.  10 . 
     FIG. 12 is a perspective view of a positioning tool according to the invention, according to a second modification, the legs being deployed in the ready position for the extraction of a clamping band, 
     FIG. 13 is an isometric view of the internal mechanism of the tool of FIG. 1, showing its operation, 
     FIG. 14 is a cross-sectional view of the tool of FIG. 1 along the axis of symmetry passing through the plane of its legs, 
     FIG. 15 is a view identical to the preceding view, in which the legs are respectively in working position and within the tool. 
     FIG. 16 is a cross-sectional view of the preceding figure, passing through the plane of symmetry perpendicular to the plane of the legs, 
     FIGS. 17 and 18 are perspective views of an automatic dispenser for clamping bands, usable in coaction with this second embodiment of tool in the initial position (FIG. 6) and in the final position before extraction (FIG.  7 ), 
     FIG. 19 is an example of the application of positioning of a clamping band on a flexible pipe by means of the tool according to the second embodiment in its working position, 
     FIG. 20 is a view identical to the preceding one, the tool being in the final retracted position just before its disengagement from the lugs of the clamping band. 
     FIG. 21 is an exploded view of the third embodiment of a positioning tool according to the invention, shown in perspective and showing all the pieces of the embodiment in relative position, 
     FIG. 22 is an elevational and medial cross-sectional view of a first arrangement of the tool according to this third modification in which the adjustment of the release mechanism is obtained by a shoe, 
     FIG. 23 is an elevational and medial cross-sectional view of a second arrangement of the tool according to the third modification, in which regulation is in this case obtained by a toothed wheel, 
     FIG. 24 shows the positioning tool of the preceding figure, from above. 
     FIG. 25 is a transverse cross-sectional view on a larger scale, of the regulating toothed wheel of the tool shown in FIGS. 23 and 24, coacting with a portion of a notched leg, in the eccentric lockage position, 
     FIG. 26 is a transverse cross-sectional view of the toothed wheel shown in FIG. 25, in the centered blocking position, 
     FIG. 27 is an elevational and medial cross-sectional view of the tool carrying a clamping band, as shown in FIGS. 23 and 24, but in the intermediate discharge position, 
     FIG. 28 is a view of the preceding tool in the final position after having discharged and freed the clamping band, 
     FIGS. 29 and 30 are fragmentary schematic views on a larger scale of the toothed wheel adjustment system of the positioning tool in its third embodiment, 
     FIG. 31 is a fragmentary view on a larger scale of the portion corresponding to the adjustment member in the cross-sectional plane XI—XI of FIG. 29, 
     FIG. 32 is a fragmentary perspective view of the end of the hook controlling the adjustment system of the tool of FIGS. 21 to  31 , showing the adjustment member of the eccentric roller coacting with the notched leg of the tool, 
     FIG. 33 is a perspective view on a larger scale of the adjustment member of the roller for the adjustment device in the arrangement with a toothed wheel, 
     FIGS. 34 and 35 are a schematic view of the rotatable jaws of the heads of the legs of the positioning tool according to the third embodiment, showing respectively according to an isometric front view, the aligned jaw (FIG. 34) and the rightwardly inclined jaw (FIG.  35 ), 
     FIG. 36 is an elevational and medial cross-sectional view of the jaw of the head of the notched leg of the tool in its third embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 to  4  of the drawings, the process for positioning resilient clamping bands  1  according to the invention comprises a clamping band dispenser  2  permitting, as shown in FIG. 1, stacking the clamping bands on edge, in a vertical column  3  having substantially the external dimensions of the closed clamping band, and having a front opening  4  of a size only just greater than the spacing of the opening members for the resilient clamping bands  1 , hereinafter called “lugs”  5 . 
     The vertical column  3  opens at its lower portion  6  into a housing  7  of a height slightly greater than the width of the clamping bands  1 ; the lateral cutout  4  permits disengaging, while guiding them, the control lugs  5  of the clamping bands  1  which are dispensed by gravity one by one, as will be indicated later on, for their withdrawal from the housing  7  by means of a manual tool  8 ; this latter is provided with two jaws  9  mounted at the ends of two legs  10  which will be, before withdrawal by the user, brought together toward each other by two compression shoes  11  disposed on opposite sides of these same legs  10  and which are actuated with a lateral movement toward each other, as shown in FIG. 2, by a mechanical device preferably motorized, controlled automatically or step by step by the user. 
     When the legs  10  of the tool  8  have been mechanically brought together, thus causing the opening of the clamping band  1  by the approach toward each other of its two lugs  5 , it is then possible; as will be pointed out later on in the description, to withdraw the tool/clamping band assembly in this position as shown in FIG.  3 . 
     The user can then very precisely position the clamping band  1  by means of the tool  8 , on a flexible pipe  12  first emplaced on a piping  13  for example of an automotive vehicle. 
     Finally, once positioned, the resilient clamping band  1  must be released by the tool  8  so that it resumes its original diameter and thus comes into counterlocking against the flexible pipe  12  on the piping  13 . To do this, the tool  8  is provided with a release mechanism of which several modifications will be described later. 
     With reference to FIGS. 5 and 6, there will now be described a particularly structure of the dispensing mechanism for resilient clamping bands  1  according to the invention. 
     The resilient clamping bands  1  stacked on edge in the column  3  of the dispenser  2  constitute an automatic supply of clamping bands arriving in the housing  7 , for example, disposed on a support table adjacent the work station; the clamping band  1  at the lower end of column  3  in the housing  7  is thus in a ready position for withdrawal by the tool  8 ; naturally, the preceding clamping band  1  will be held by a retractable blocking system  16  which is successively withdrawn to permit the descent of the next clamping band for withdrawal. 
     According to FIG. 6, showing a top plan view of the positioning of the clamping band  1  at the moment of its arrival in the housing  7  of the dispenser  2  just before emplacing the tool  8  for its withdrawal, the dispensing mechanism comprises first two positioning shoes  17  disposed on opposite sides of the lugs  5  of the lowermost clamping band  1 , so as to block the clamping band  1  in this position (full lines in FIG.  6 ); at this time, the legs  10  of the tool  8  (not shown) can be inserted so as to cause the jaws  9  respectively to coincide with the lugs  5  of the lowermost clamping band  1 . The tool  8  comes into abutment against the shoes  17  which hold the clamping band  1  in position and is guided laterally on the two shoes  11  which ultimately will serve to bring together the two lugs  5  toward each other, so as to enlarge the clamping band  1  (broken line position in FIG.  6 ). According to the process, assume that the jaws  9  are in good position about the lugs  5 , the shoes  11  are automatically or by manual control, brought toward each other in the direction of the arrows F 2  of FIG. 6; in the case of automatic actuation, the drive of the shoes  11  can be controlled by detectors of the position of the legs  10  of the tool  8  or else by pressure detectors when these same legs are in contact with the compression surfaces of the shoes  11 . Once the approach of the legs is mechanically carried out by the shoes  11 , the clamping band  1  is thus in the open position and it is ready to be withdrawn, not only from the shoes  11  but also from the shoes  17  so as to disengage (reversal of the movements Fl and F 2 ) from the opening of the housing  7  and thus to extract without difficulty the pre-stressed clamping band  1 . 
     As will be described for the various modifications which follow, the tool  8  is designed to maintain the compression of the lugs  5  of the clamping band  1  thus pre-stressed, during all the transport from the dispenser  2 , to the application site of the clamping band  1 . 
     It follows that other arrangements can be adopted, particularly as to the configuration of the dispenser  2  according to the invention; the function of the clamping band dispenser can thus be separated from the pre-gripping function obtained by approach of the shoes  11  thanks to the mechanical means, for example motorized. One could for example imagine a withdrawal of the clamping bands by the tool  8  whose jaws would be adapted to simple snapping on to the lugs  5  in the rest position, the tool and the clamping band being able then to be presented to a following station, permitting carrying out pre-clamping, which is to say the pre-stressing of the resilient clamping band  1 , the rest of the process remaining the same. 
     There will now be described with reference to FIGS. 7 to  11 , a first modification of the hand tool  8  whose mechanism permits the use of the process according to the invention. 
     The kinematics of this mechanism are especially shown in FIGS. 7 and 8, showing respectively the tool  8  in the rest position, in full lines, and in the gripping position shown in broken lines in FIGS. 7 and 8; for easy understanding, the references connected with the constituent elements of the tool will be primed when they refer to these same elements in the working position. 
     Tool  8  permitting the extraction and positioning of a resilient clamping band  1  from the housing  7  of a dispenser  2 , comprises a head  20  from which emerges the two legs  10  supporting the two jaws  9  shaped conventionally to be adapted to the particular shape of the lugs of the clamping bands  1  commercially available, a body  21  receiving the release control mechanism of the legs  10 , finally a sleeve  22  for gripping by the user; according to a preferred arrangement of this tool  8 , the head  20 , the body  21  and the sleeve  22  are of overall cylindrical shape and are stacked along the same longitudinal axis XX′. The two legs  10  of a case a are articulated like scissors about an axle  23  secured to the head  20  of the tool  8 ; the two legs are prolonged beyond the articulation  23  for a length b according to a given ratio R=a/b which depends not only on the size of the clamping bands  1  which are used but also on the overall geometry of the tool; this ratio is easily determined by those skilled in the art during preparation of the tool. At each of the ends of the legs  10  opposite the jaws  9 , is articulated a rod  24  whose length here depends again on the overall geometry of the tool which will be easily determined by those skilled in the art; the free ends of the two rods are connected and articulated about a same axle  25  secured to a head  26  connected in a manner which will be described in greater detail later, to a shaft  27  which can move along the axis XX′ within the tool  8 , guided by a longitudinal channel  28  provided at the center of the body  21 ; the shaft  27  is moreover secured to the head  26  in an upper recess  29  of the body  21  opening into a cavity  30  within the head  20  of a sufficient size to permit the lateral extension of the ends of the legs of a length b of the legs  10  when these latter deploy about their articulation  23 ; the shaft  27  is itself prolonged toward the sleeve  22  to come into resilient abutment  31  against a member, such as a helical spring  32  for example, which tends to return longitudinally said shaft  21  toward the head  20  of the tool  8 , thereby tending to space the jaws  9  as will be explained later; a blocking system is moreover associated with the shaft  27  to permit freely and automatically its linear movement along XX′ when the jaws  9  move together, which is to say when the rod compresses the resilient member  32 , and, on the contrary, to prevent its reverse movement, except to actuate a control  14  provided for this purpose automatically to space the jaws  9 , in the gripping position of a clamping band  1  at the lower end of the dispenser  2 . 
     Referring to FIG. 7, there will now be described the general kinematics of the tool  8  according to this first modification: by the external action of the shoes  11  of the dispenser  2  in the direction of the arrows F 2  of the drawing, the legs  10  articulated at point  23  move simultaneously in the direction of the arrows F 3  thereby causing displacement F 4  of their legs of a length b, the four elements of the legs thus taking the configuration in fine broken lines of the figure and it will be seen that the articulation  25  of the two rods  24  undergoes because of this movement an offset along the axis XX′ of the tool toward its rear portion, which is to say toward the sleeve (arrow F 5 ). This retraction of the articulation  25  gives rise to a rearward offset of the head  26  and hence a retraction of the shaft  27  which thus compresses the spring  32  bearing on the end  33  of the sleeve  22  of the tool  8 . At this time, it is important to block the legs  10  in their gripping position, permitting as has been seen, the withdrawal and the positioning of the pre-stressed resilient clamping bands  1 . This blocking is obtained by a blocking system which prevents the reverse movement of the shaft  27 , which is to say rising toward the head  20  of the tool  8 . To do this, and generally speaking, the blocking system of the shaft  27  is obtained by giving to said shaft an axial conicity of suitable cross-section enlarging from the head  26  to the resilient abutment  31  which will coact with a conical wedge  35  of suitable conicity with an axis perpendicular to that of the shaft  27  and which can move axially downwardly (FIG. 8) by an action of the control  14  and upwardly (by the reaction of a resilient member  36 , in principle a helicoidal spring), said wedge  35  being disposed in a well  37  to be constantly in frictional engagement with the conical portion of the shaft  27  such that its smallest cross-section being upward (FIG. 8) which is to say on the side opposite the spring  36  pressing back the wedge  35  upwardly, its does not constitute a blocking brake when the shaft  27  moves to the rear of the tool by compressing the spring  32 , which is to say definitively during approach of the jaws  9 , and on the contrary has sufficient friction to prevent the reverse movement of the shaft  27  urged both by the gripping force of the pre-stressed clamping band  1  and by the return force of the spring  32  which it compresses. 
     According to a preferred configuration of the blocking system which has been described, the conicity of the shaft  27  results from a flat machined along one of its generatrices, at least for an effective length corresponding to its axial movement during maximum clearance of the free jaws  9 , with a machining slope in the radial direction producing a progressive ramp  40  adapted to coact with the conical wedge  35 , the slope of the ramp  40  being just calculated to obtain relative sliding with the wedge  35  in one direction and a blocking in the other direction as a function of the mechanical characteristics of the tool  8  and the clamping bands  9 . Similarly, and according to another preferred modification of the invention, the conical wedge  35  is of the cylindrical wedge type with a cut surface known as a “bicycle wedge” whose upper end, of smallest cross-section, opposite the return spring  36  coming into bearing against the internal wall of the body  21  of the tool, opens freely outwardly of the body so as to be accessible by pressure exerted by the user downwardly (FIG. 8 or FIG. 11) when he desires to disengage the tool  8  from the clamping band  1  correctly positioned on the flexible pipe, a control trigger  14  preferably being able to lessen the force necessary to push back said wedge  35 . 
     There will now be described the conjoint action of the shaft  27  and the wedge  35 : when the shaft  27  returns toward the sleeve of the tool at the time of pre-gripping of the legs  10 , it will be seen in FIG. 7 that the ramp  40  passes from a position in full line to a position  40 ′ in broken lines, thereby freeing in the well  37  guiding the wedge  35  if it does not swing, a space, corresponding to the radial spacing a between the two positions, which naturally, the wedge  35  immediately fills by rising in the direction of arrow F 6  of FIG. 8 thanks to its return spring  36  and its path upward is thus limited only by the sufficient inclination of the cut surface. It will thus be understood that this new position is irreversible, which is to say that the shaft  27  cannot advance further, because it would then press downwardly the wedge  35 , however this movement is impossible because it would cause friction which is very much greater than the return force; naturally the slopes of the wedge and the ramp  40  of the shaft  27  are accordingly calculated. Precisely, the wedge  35  plays the role of a wedge to block the forward translation of the shaft  27 . Only a downward vertical and transverse pressure on the wedge  35  in the direction opposite the arrow F 6  in FIG. 8, could again disengage a space α giving rise immediately to freeing the shaft  27  which could thus rise toward the head  20  and open by the effect of the rods and of the scissors, the legs of the jaws  9  which place the tool in the rest position ready to perform a new withdrawal of a clamping band from the dispenser  2 . According to a preferred embodiment, there is provided in line with the wedge  35  a trigger  14  secured to the body  21  of the tool, providing a bearing lever for controlling release. 
     Referring to FIGS. 9 and 10, there will now be described several embodiments of the tool  8  according to its first modification. According to a first embodiment, the head  20  of the tool  8  can be totally pivoted on itself about the longitudinal axis XX′, thereby permitting pivoting in all directions of the space of the plane containing the two legs  10  supporting the jaws  9 . This improvement of the tool is particularly advantageous to avoid any twisting of the hand of the user both at the time of withdrawal of the clamping bands and at the time of their positioning. 
     The rotation on itself of the head  20  about the axis XX′, about a circular rail  41  at the end of the body  21  of the tool, is rendered possible thanks to the particular mounting of the head  26  which is naturally driven by the rotation of the head  20  at the same time as the legs  10 , about the head  42  of the shaft  27  which can not undergo any rotation about itself by reason of its ramp  40  which must rest facing the ramp of the wedge  35 ; such a mounting is for example obtained by the coaction of a shaft head  42  which is flared to provide a shoulder coacting with a recess provided at the base of the head  26  surrounding just the head  42  of the shaft such that it ensures mutual rotation of the two members but prevents any axial translation. 
     According to another important form of this first modification, the legs  10  of the tool  8  supporting the jaws  9  can be inclined at an angle varying from 0 to 90° relative to the plane that they define when they are straight in accordance for example with FIGS. 9 and 10 of the drawings. It follows that the inclination of the legs  10  can be effected definitively upon construction of the tool  8  or else, according to a conventional construction well known to those in the art, can be adjusted as desired by the user from a vertical position of FIGS. 9 and 10 to a final position at 90° permitting lateral gripping of the resilient clamping bands. Naturally, the single or variable inclination of the legs  10  can be associated with the rotatable head  20  described in the preceding embodiment, to form a particularly universal tool. 
     According to a secondary characteristic, it is possible to adjust the pressure on the shaft  27  by the spring  32  giving rise to the release of the jaws  9  so as to place the tool  8  in gripping or rest position; to do that, there can be provided axial adjustment of the abutment  31  mounted at the end of the shaft  27  thanks to a cap positionable by a nut  44  coacting with the end of the shaft  27 , screwthreaded for this purpose. 
     According to a second modification, the autonomous positioning tool  50  according to the invention which will now be described with reference to FIGS. 12 to  20 , uses all the steps of the positioning process for resilient clamping bands described above. For easy comprehension of the pieces and portions of pieces cited in the description which follows, and which are already used in the first embodiment, the same reference numerals will be used. 
     As in the first modification, the tool  50  coacts with a dispenser  2  for clamping bands  1 , arranged at a fixed position so as to preload them, which is to say to open them, bringing their control members, the lugs  5 , together, by means of two compression shoes  11  actuated with lateral movement toward each other by a mechanical device which is preferably but not necessarily power driven, which can be controlled automatically or step by step by the user himself. 
     An example of a dispenser  2  provided with power driven and automatically controlled compression shoes coacting with the manual tool  50 , is shown in the accompanying FIGS. 17 and 18; its operation will be described later. 
     With reference to FIGS. 12 to  16 , there will now be described the positioning tool  50 : the latter comprises two legs  51  normally identical, provided at one of their ends with jaws  52  mounted facing each other to be adapted to lugs  5  of a conventional resilient clamping band; at their other end, the legs  51  are articulated to each other in the plane that they form along an axis  53  which itself is perpendicular, to open freely between a closed position in which the jaws  52  open the clamping band  1 , to a position extended as of V, which positions the same jaws to engage or disengage the lugs  5  of the clamping band  1  respectively at the bottom of the dispenser  2  or discharged after positioning; as shown in FIG. 13, the articulation axle  53  of the two legs  51  is slidably mounted along the axis of longitudinal symmetry of the legs  51  within a casing  54 , outwardly shaped to serve as a gripping member for the tool  50  and internally such that when the legs  51  are within said casing  54  and in abutment with the bottom of the same casing, only the jaws  52  emerge from the opening  55  of the casing  54  at a distance shown in FIGS. 15 and 16, sufficient to keep the lugs of a clamping band  1  in good position; at this time, the legs  51  are in the closed position against the internal side walls of the casing  54 ; the tool  50  is thus in autonomous position for work consisting, as will be pointed out later, in extracting a clamping band  1  from the dispenser  2 , bringing it onto a flexible pipe in its open position to proceed to its positioning on piping before release of the clamping band; to this end, and conversely when the legs  51  of the tool  50  are slid toward the outside of the casing  54  until reaching a stop abutment  56  near the opening  55  of the casing, they are thus located in deployed V shaped position as shown in cross-section in FIG. 14, thanks to a resilient member  57  pressing them back against the internal side walls of the casing  54  which for this purpose has at least an enlargement  58  in its opening  55 . 
     According to an essential characteristic of the present modification, the articulated legs  51  each have along their external edge  59  at least one series of three facets  60 ,  61 ,  62  that are flat and perpendicular to the plane of the legs  51  when they are deployed, connecting with a convex profile as shown on the left leg in FIGS. 12 and 13 particularly; a first facet  60  extends from the jaw  52  to within the leg  51  to flare outwardly over a distance corresponding to the remaining external portion when the legs  51  are in abutment within the casing  54  as shown in FIGS. 15 and 16; a second facet  61  is connected to the first at an angle bringing it into a position parallel or slightly re-entrant relative to the vertical plane of symmetry of the V of the legs  51  over a distance which will be recited later; finally, the third facet  62  is connected to the second at an inward inclination of a gentle slope in the direction of the articulation axis  53 . Shoes  63  of maximum width a are mounted on pivots  64  perpendicular to the plane of the legs on opposite sides of the internal side walls of the enlarged portion  58  of the opening  55  of the casing  54  to coact with the second and third facets  61  and  62  of the legs, respectively, to create first a sufficient braking of the legs  51  when these latter are in abutment within the casing  54  and hence urged to the maximum by the resilient force of the open clamping band which tends by this fact to press them back toward the exterior of the casing, and on the other hand, to facilitate the extraction of the legs  51  outside the casing  54  at the time of depositing the clamping band  1  on a flexible pipe  12  by balancing and rendering progressive the deployment of said legs  51 . 
     According to a second characteristic of the tool  50 , there is provided a groove  65  along the lower portion of the third facet  62  of each leg  51 , permitting each shoe  63  to be enclosed in the corresponding leg  51  corresponding to the time when the articulation axle  53  of the deployed legs arrives in abutment at  56  on a side of the opening  55 , creating an abrupt increase in the opening of the same legs  51 ; at this time, the jaws  52  are totally disengaged from the lugs  5  of the clamping band  1  which is completely emplaced on the flexible pipe  12 , which permits retrieval of the tool  50  for a new operation at the dispenser  2 . Moreover, the reception of the shoes  63  in the grooves  65  constitutes a temporary holding position of the legs  51  which thereby benefit from a stability of opening with respect to external forces on the tool, for example at the time of emplacement in the dispenser  2  as will be pointed out further on. 
     There will now be described a modified embodiment of the mechanism of the tool  50  with reference to FIG.  13 . The two legs  51  machined of special steel to produce the jaws  52  and the different facets  60 ,  61 ,  62  as well as the groove  65  according to the characteristics detailed above, are articulated to each other to be deployed in a V shape thanks to a pivot  53  perpendicular to the plane of the legs and passing on opposite sides of this plane to serve as sliding lugs between two superposed openings  66  extending along the axis of symmetry of the tool over a distance comprised between a lower abutment  67  corresponding to the position of the tool when its legs are brought together within the casing  54  and an upper abutment  56  corresponding to the position of the legs completely deployed in V shape as pointed out above; naturally, the axle  53  for articulation of the legs slides without play between these two abutments  56 ,  57 . 
     The two openings  66  are provided on two metallic members  68  preferably identical to each other and of general T shape, cut out from sheet metal to constitute the framework of the internal mechanism of the tool  50 . Between the transverse portions of the T of the members  68 , are mounted on pivots  64  two shoes  63  such that these latter can oscillate freely on opposite sides of the facets  62  of the external edge  59  of each leg  51  which are constantly held in position against said shoes  63  thanks to a pair of spiral springs  57  mounted in recesses provided for this purpose just above the articulation axle  53 . The two members  68  are held one above the other by two articulation axles  64  of the shoes  63 , serving as a crosspiece in the upper portion of the T and by a crosspiece of the same type  69  provided at the lower end of the members  68 . 
     Thanks to this extremely simple mechanism, it is possible easily to obtain the two functional positions of the legs  51 , either deployed as a V as shown in FIG. 13, or regripped by pushing on the legs  51  to move the articulation axle  53  toward the lower abutment  67  with the result of bringing together the two legs  51  about the shoes  63  which contribute to holding it in closed position as has already been indicated. Finally, there are provided two shells  70  preferably identical and of a plastic material, to adjust themselves about the two T shaped members  68  and to be fixed by means of screw  71  in screw-threaded bores  72  preferably provided on said members  68 . 
     With reference to FIGS. 17 to  20 , there will now be explained the particular operation of the tool according to the second embodiment, in coaction with the dispenser  2 , to carry out gripping of a flexible pipe  12  on piping  13 . 
     With reference to FIG. 17, the legs  51  of the tool  50  are in deployed position, which is to say in the position for extracting clamping bands on the platform  80  of the dispenser  2 . The tool  50  enters the dispenser with a transverse movement P (FIG. 18) about the lugs  5  of the clamping band  1  at the lower end of the internal housing, such that the jaws  52  of the tool come into contact with the two compression shoes  11  automatically actuated by two jacks  81  disposed facing each other and preferably actuated when the tool  50  is well positioned; it follows that the dispenser  2  could be constituted by different means than those shown in FIGS. 17 and 18; in particular, the jacks  81  actuating the shoes  11 , could be replaced by a manual mechanism which demultiplies the action of the foot or the hand of the user in an environment in which it would be difficult to provide a source of compressed air for example; similarly, there is here provided a supply of clamping bands that are stacked in the column  3  of the dispenser  2  but this device could be changed for a simpler arrangement in which the clamping bands  1  would be disposed one by one, directly on the internal housing of the dispenser  2  in proper position to be grasped between the jaws  52  of the tool  50 , as pointed out above. 
     When the shoes  11  have been actuated in the direction of the arrows F 2  of FIG. 17, the tool  50 , whose legs  51  have been brought together in the direction of arrows F 3  of FIG. 17, is in the position of FIG. 18, it then suffices for the user to press inwardly of the dispenser  2  (in the direction of arrow P, FIG.  18 ), the handle of the tool  50  such that the legs  51  enter the interior at the bottom of the casing  54  as has been explained above; it will be noted that the guiding and braking shoes  63  of the legs  51  are naturally ineffective at this time, because the two legs have been brought together, which is to say disengaged from the groove  65 . Thus, when the handle of the tool  50  has been totally pressed against the platform  80 , (FIG.  18 ), these means actuate the dispenser  2  and in particular the jacks are then released and the shoes  11  withdrawn from the jaws  52 , which remain in clamped position, which is to say in the position to open the clamping band  1 , because at this time, the legs  51  within the casing  54 , are again in straight contact with the shoes  63  which, thanks to the convexity of the legs, are located directly in contact with the facet  61 , which produces sufficient braking to oppose the force created by the compression of the clamping band which tends to press back the legs outwardly of the tool  50 ; the latter is thus in the position shown in FIGS. 15 and 16. Naturally, the reverse movement in the direction F 2  (FIG. 8) of the jacks  81  to disengage the shoes  11  on each side of the jaws  52 , is preferably controlled by position detectors such that the tool  50 , and more specifically its casing  54 , will be located in good position on the platform  80 . It will be further noted here, as in the preceding modification, that in case of breakage of the clamping band at the time of its compression, there is no danger for the user because the ejection of the clamping bands or portions of clamping bands takes place within the dispenser  2 . 
     Naturally, when the shoes  11  are retracted, it then suffices to extract in the direction of the arrow T (FIG. 18) the tool-clamping band assembly, which can thus be transported from the dispenser  2 , to the emplacement position, because this assembly is totally autonomous. According to FIG. 19, the tool-clamping band assembly is disposed about the flexible pipe  12  which is pre-threaded over the piping  13 , and it will be seen that it is easy to position the clamping band  1  at the place provided by the manufacturer, given the small size of the tool  50 . When the clamping band  1  is well positioned, it then suffices to retract, according to arrow R of FIG. 20, the handle  54  of the tool  50 , by bearing on the clamping band  1  which is necessarily against the flexible pipe  12  and which accordingly can no longer move laterally during the discharge operation, which constitutes an improvement relative to the preceding tool. The retraction of the handle  54  moreover takes place very progressively thanks to the arrangement of the shoes  63 , which slide along the legs  51  from the braking facet  61  in the gripped position to the end of the inclined facet  62 , ensuring progressivity of retraction; here again, when the shoes describing the inclined facet  62  arrive at the level of the slot  65 , there is again created an abrupt opening of the legs  51 , finally disengaging the lugs  51  of the clamping band  1  which remains in proper position on the piping. 
     It follows that the legs  51 , which are in principle straight, could have in particular cases curvatures to facilitate the emplacement of the clamping bands  1 ; there is thus no reason that the end portions of the legs  51  could not be inclined or inclinable between 0 and 90° relative to the plane defined by the latter when they are straight, whereby the operation of the tool  50  would not be affected. 
     There will now be described with reference to FIGS. 21 to  40 , a third embodiment of an extraction and positioning tool  100  using the assembly of steps of the assisted positioning process for resilient clamping bands according to the invention. For good understanding, the parts and portions of parts mentioned in the description which follows and which were found in the preceding embodiments, will be given the same reference numerals. 
     As before, the tool  100  coacts with a dispenser  2  of resilient clamping bands  1  arranged at a fixed station to precompress the clamping bands  1 , which is to say to open them by bringing together their control members called lugs  5  by means of two pressers or compression shoes  11  actuated with a lateral movement toward each other by a mechanical device, preferably but not necessarily motorized, which can be controlled automatically or step by step by the user. 
     With reference to FIG. 21, the tool  100  also comprises two legs  101  and  102  provided at one of their ends, so called head of the leg, with jaws  103  comprising means which will be described later on, to adapt them to the lugs  5  of a resilient clamping band  1 ; at their other end, the legs  101  and  102  are articulated to each other in the plane which they form, thanks to an axle  53  which is perpendicular to them so that they can open freely under the force of the clamping band  1 , from a near position in which the jaws  103  maintain the compression of the clamping band, to a position deployed in V shape permitting said jaws either to engage or to disengage the lugs  5  of the clamping band  1 , according to whether the latter is respectively in position in the fixed dispenser  2  or released after its emplacement on a flexible pipe  12 ; different means which will be described in greater detail later, are provided such that, when the legs  101  and  102  are mounted by sliding their articulated ends along their longitudinal axis within and at an abutment  105  at the bottom of, a casing  104 , only the jaws  103  emerge from the opening of said casing with which the legs coact to be held as shown in FIGS. 22 and 23, in a near position and stabilized thanks to the braking means which will be described later and conversely, when said legs are progressively slid outwardly under the controlled action of the force of the clamping band to a stop abutment  103  near the opening of the casing  104 , they deploy in a V shape thanks to a resilient member  57  pushing them apart. 
     According to a characteristic configuration of this modification of the tool, the longitudinal sliding means for the two legs  101  and  102  within the casing  104  are provided on the one hand by sliding of the articulation axle  53  between two opposite grooves  107  for example sunk in the internal wall of the casing  104  and it is preferable to provide at the ends of the articulation axle  53  ball bearings  108  ensuring better coaction with the guide grooves  107 ; on the other hand, the legs  101  and  102  are guided in their sliding by two abutments which are positioned transversely to the opening of the casing  104  on opposite sides of the legs  101 ,  102  whose external edges, respectively  101  and  110 , are machined to constitute for one  102 , a smooth track and for the other  101 , a track that is at least partially notched, effecting under the force of a compressed clamping band a free guiding and sliding along the leg  102  and a free guiding or braking along the leg  101  by the bias of a control regulation mechanism (of which a preferred embodiment will be described later on with reference to FIGS.  29  and  30 ), thanks to which the two legs  101  and  102 , leaving their innermost position on abutment  105  at the rear end of the grooves  107  in which the clamping band  1  is totally compressed, progressively deploy outwardly until the articulation axle  53  arrives at abutment  106 , at the other end of the grooves  107  beside the opening and located at a good distance forwardly of the transverse abutments, limiting the angle of opening of the legs to a V shape of a value sufficient to permit disengagement of the lugs  5  of the clamping band  1 , when the latter is in place on the flexible pipe. 
     As in the preceding embodiments, the legs  101  and  102  of the tool  100  are machined from flat steel in the general shape shown in the figures; it follows that the sizes, lengths, width and thickness will be easily computed by one skilled in the art to ensure the mechanical strength of the positioning tool given the ranges of clamping bands which will be positioned by the tool; thus, the external edges  109  and  110  of the legs will coincide in principle with the thickness of each leg. 
     With reference to FIGS. 22,  23 ,  27  to  31 , the transverse abutments coacting with said external edges are constituted, for the leg  102  whose external edge  110  is machined smooth, by a smooth roller  111  freely turning about an axle  112  perpendicular to the plane of the legs and secured to the body of the tool, thereby giving the leg  102  a free guiding during its sliding. As to the other leg  101 , called hereinafter the notched leg, and according to a first embodiment shown in FIG. 22 of the drawings, the transverse abutment coating with the external edge  109  that is at least partially notched, is constituted by a fixed shoe  113 , secured to the body of the tool substantially at the same level as the smooth roller  111  forming the other transverse abutment and coming into contact with the notched track  109  to constitute a brake to the natural tendency which the legs have to deploy outwardly when they are subjected to the load of a pre-compresed clamping band as shown for example in the intermediate position in FIG.  27 . The shoe  113  is constituted of a resilient material, for example an elastomer mounted with slight rearward bias on a pivot  114  perpendicular to the plane of the legs to come into resilient bearing against the notched portion of the leg  101  thanks to an adjustment wedge  115 . 
     According to a second preferred arrangement of the invention, the transverse abutment coacting with the notched edge  109  of the corresponding leg  101  is, with reference to FIGS. 23 to  31 , constituted by a toothed wheel  116 , located above the notched leg  101  and coplanar with the latter, having an access O perpendicular to the direction of movement A (FIG. 26) of said leg. The toothed wheel  116  comprises a toothed crown  117  having at its periphery a regular alternation of teeth  117   a  separated by hollows  117   b.  The pitch of the teeth  117   a  of the toothed crown  117  is equal to the pitch of the teeth  101   b  of the notched leg  101  and the teeth  117   a  of the toothed crown  117  are in engagement, in the lower portion of said crown  117 , with the teeth  101   a  of the notched leg  101  as appears in FIGS. 25 and 26. The toothed crown  117  has a coaxial bore  118  which is traversed by a fixed support shaft  119  with an axis O 1  parallel to the axis O. The support shaft  119  has a fixed diameter less than that of the bore  118  of the toothed wheel  116  such that there exists a radial play between the internal surface of the bore  118  and the external surface of the shaft  119 , this play, which could be left free in theory, being, in the present embodiment, filled with an element of resilient material, preferably an elastomer, as will be mentioned later on. Because of this, the toothed crown  117  can move transversely relative to the central fixed support shaft  119 , over a small distance (O, O 1 ). 
     There will now be explained the operation of the device for blocking/unblocking the legs of the tool provided with a toothed wheel  116  as shown in FIGS. 25 and 26. In FIG. 25, the device is in the blocking position in which the toothed crown  117  is eccentric relative to the fixed support shaft  119 . In this case, the notched leg  101  is subjected to a force F directed upwardly, which is to say toward the axis O 1  of the support shaft  119 , resulting from the stress of the pre-compressed clamping band  1 , so that this notched leg  101  has been moved to the upper position and exerts a pressure on the toothed crown  117 . As a result of this pressure, the toothed crown  117  is pushed upwardly and the internal surface of its bore  118  is applied against the lower generatrix of the fixed support shaft  119  to which it is tangential. In this position, the axis O of the toothed wheel  116  is located at a certain distance above the axis O 1  of the shaft  119 , because of the movement of the notched leg  101  and the toothed crown  117  upwardly, until this crown  117  comes to bear against the shaft  119 ; the summit of the tooth  101   a  of the notched leg  101 , which is engaged in the lower hollow  117   b  of the toothed crown  117 , is thus located within the pitch circle P of the teeth  117   a,  shown in broken lines in FIGS. 25 and 26, so that the two teeth  117   a  of the toothed crown  117  which are the lowest, are blocked in the two corresponding adjacent hollows  101   b  of the notched leg  101 . As a result, a mutual blocking of the notched leg  101 , and of the toothed wheel  116 , with the result that the notched leg  101  is immobilized. 
     On the other hand, when the force F is no longer exerted on the notched leg  101 , which is to say when the swinging mechanism is actuated which will be described later and which is shown schematically in FIGS. 29 and 30, the leg  101  thus returns to a low position shown by arrow H (FIG. 26) in which the summits of its teeth  101   a  are located outside the pitch circle P such that the teeth  117   a  of the toothed crown  117  are no longer blocked in the notches  101   b  of the notched leg  101 . The toothed wheel  116  can then turn freely in both directions of the arrow B (FIG. 26) by floating about the fixed shaft  119  in a substantially centered position and the toothed leg  101  can thus move freely in translation in the direction of the arrow A (FIG.  6 ). 
     According to a particular characteristic of this modified embodiment, it has been seen that the radial play between the bore  118  and the toothed crown  117  and the shaft  119  is preferably filled by a resilient ring  121  (FIG. 31) for example of elastomer, which is sufficiently compressible to permit the necessary transverse offset of the toothed wheel  116  relative to the shaft  119 . 
     When the notched leg  101  is pressed against the toothed wheel  116 , by exerting the force F (FIG. 25) there is a compression of the resilient ring  121  and the blocked condition returns. On the contrary, as soon as the pressure of the leg  101  weakens or becomes zero, the toothed wheel  116  immediately self centers, which permits avoiding the “drag” effect of a free pinion, (the toothed crown  117 ), at the moment of engagement/disengagement of the teeth (vibration, noise, etc . . . ) and performs a more rapid and more precise operation when the device is used in a very repetitive or gradual manner, (blockage/unblockage corresponding to each advance of a tooth of the toothed wheel  117 ). 
     According to a secondary characteristic of the invention, the toothed crown  117  of the toothed wheel  116  is associated with two bored lateral flanges  122 , forming together a recess adapted to receive, through the bore, the resilient ring  121  mounted on the support shaft  119  fixed to the casing  104 , the diameter of the bore of the flanges  122  being computed so as to obtain at least a sufficient displacement to create the blocking effect and, at the maximum, to limit the compression of the ring  121  and thus to avoid its deterioration, during heavy loading resulting from use with large clamping bands  1 . 
     There will now be described with reference to FIGS. 29 to  31 , the swinging mechanism usable in one or the other of the configurations of transverse abutments, previously described, whether with a shoe  113  (FIG. 22) or with a toothed wheel  116  (FIG.  23 ). To this end, a trigger  123  articulated directly or indirectly on the casing  104  about a pivot  124  with an axis parallel to the axis of the transverse abutments  113 ,  116 , that is to say perpendicular to the plane of the legs  101 ,  102  as shown in FIG. 29, drives a roller  125  mounted on a shaft  126  with an axis parallel to the axis of the pivot  124  and positioned between the latter and the control handle  123   a  of the trigger  123 . According to this arrangement (FIG.  29 ), the roller  125  comes to rest only against the notched region  109  of the corresponding leg  101 ; thus, when the trigger  123  is not actuated by pushing on the handle  123   a,  the roller  125  has no effect on the leg  101  which remains braked against the transverse abutments  113 ,  116  because of the force F resulting from the load of the pre-compressed clamping band  1 . 
     With reference to FIG. 30, when the user presses the handle of the trigger  123  (arrow G), the roller  125  moves in the same way, in rotation about the axle  124  of the trigger, which pushes back the notched leg  101  toward the other leg  102  such that the notched region  109  of the leg  101  will be offset from the shoe  113  in the first embodiment or the teeth  117  of the toothed wheel  116  in the other embodiment; it will thus be understood that the leg  101  can slide freely forwardly under the force of the load of the pre-compressed clamping band, tending to unload it; as soon as the trigger  123  is released, the blocking position is resumed each time against the shoe  113  or the toothed wheel  116  and so on for stepwise or gradually controlling the deployment of the legs  101 ,  102 , which is to say the operation of releasing the clamping band  1  about a flexible pipe  12 . 
     According to a secondary characteristic of this third modification of the positioning tool, the external edge  109  of the notched leg  101  comprises over all its useful sliding length, which is to say the length of the edge adapted to enter into contact with the transverse abutment  113  or  116 , a notched region  109   a  and at least one collateral smooth region, preferably two smooth regions  109   b,    109   c,  on opposite sides of the notched region on which comes to bear at least one portion of the smooth rolling strip  127  (FIG. 31) of the control roller  125  which can thus roll freely on the smooth zone or zones  109   b,    109   c  whilst exerting a force R (FIG. 30) tending to push back the leg  101  toward the leg  102 , thereby freeing the deployment of the same legs. 
     According to a preferred embodiment of the invention, the roller  125  is provided on a portion of its peripheral strip, with a ring  128  of flexible and resilient material, for example of elastomer, of an external diameter greater than that of the rolling strip  127  of the roller, thereby providing a shock absorber effect in the first phase of control, when the trigger  123  is actuated, by creating a resilient bearing for said ring  128  on the notched region  109   a  of the corresponding leg  101 , rendering more progressive and more flexible its passage from the braked position (FIG. 29) to a free deployed position (FIG.  30 ). 
     According to an even more advantageous arrangement, the roller  125  is constituted by two metallic flanges  129  disposed on opposite sides of an elastomeric ring  128  mounted on the same shaft  126 , of greater diameter and of a thickness identical to the width of the notched region  109   a  extending over the central region of the external edge  109  of the notched leg  101 , nestled to the right and left between two smooth rolling strips  109   b,    109   c,  which are in line with the smooth rolling strip  127  of each flange  129  of the roller  125 , to transmit the force R (FIG. 30) to the leg  101 . 
     According to another secondary characteristic of this modification, the height of the teeth  101   a  of the notched region  109   a  on the external flange  109  of the corresponding leg  101  increases regularly from the head of this leg  101  to its end near the articulation  53  without at the same time changing the general shape of the teeth so as not to modify its ratio with the teeth  117  of the toothed wheel  116  in particular; it has thus been proposed to machine the smooth regions  109   b  and  109   c  of the external edge  109  of the notched leg  101  so as to give them a progressive inflection from the head to the other end near the articulation. In this way, the engagement of the teeth, particularly in the shock absorbing ring  129  of the roller  125  of the swinging mechanism, will be all the greater as the deployment of the legs outwardly is great; thus at this instant the speed of extraction of the legs is greater and this is the reason for which a progressive shock absorber has been sought. 
     Complementarily to the progressive inflection rearwardly of the smooth zones of rolling  109   b  and  109   c  of the external edge  109 , it has been provided to mount the two flanges  129  that sandwich the elastomeric ring  128 , to form the roller assembly  125 , on a shaft  126  whose extent in line with the ring  128  is eccentric as shown in FIG. 33; on opposite sides of the eccentric bearing  130 , the bearing  131  designed to receive the two flanges  129  are identical and centered on the axis of the shaft  126 . To the extent to which the flanges  129  and the elastomeric ring  128  can turn freely on the shaft  126 , it will be understood that by a rotation of the latter about its axis, the flanges  129  are not subject to any radial displacement, whilst the ring  128  moves radially progressively in the plane of the legs as a function of the eccentricity which has been given to the bearing  130 . Thus, by successive angular indexing carried out with a simple member  132  (FIGS. 32 and 33) sandwiched in a recess  133  of the casing  104  (FIGS.  21  and  31 ), there is obtained an offset of the shock absorbing ring  128  relative to the rolling strips  127  of the roller which have not moved, which increases the height of the resilient mass adapted to coact with the teeth  101   a  of the notched region  109  of the leg  101 ; as is seen in FIG. 32, the roller  125  mounted at the end of the trigger  123  has an eccentric central region corresponding to the ring  128  between two coaxial regions corresponding to the two flanges  129  bearing on the smooth regions  109   b  and  109   c  of the leg  101 ; it will be understood that to vary the height of the resilient strip of the roller  125 , it suffices to carry out a rotation of the member  132  which, as shown in FIG. 32, is constituted by a simple square embedded in a homothetic recess  133  provided for this purpose in a corresponding portion of the casing  104 . According to a particular arrangement, the trigger  123  carrying the shaft  126  and the roller  125 , is mounted on its axle  124  thanks to two hooks  134  that open upwardly and are encased from below about said axle  124  such that the trigger  123  will be held at its end by the two hooks  134  and bearing by the roller  125  on the edge  109  of the notched leg  101  by the reception of the adjustment member  132  of the eccentric shaft  126  in the recess  133  of the casing  104 . It is very simple to modify the adjustment of the eccentricity of the shaft  126  by disengaging the hooks  134  from the axle  124  and pulling outwardly the trigger  123  to remove the member  132  from its recess  133  and to give it a different indexing. As a supplement, there can be provided index marks by marking indicia  135  on the member  132  which remains visible above the tool once the trigger  123  is mounted. 
     According to an important characteristic of the invention, with reference to FIGS. 34,  35  and  36 , each head of the legs  101  and  102  comprises a rotatable jaw  103  that can be oriented in a plane perpendicular to the plane of the legs about an axis zz′ passing through the two heads in the medial plane of the legs, which permits positioning clamping bands  1  in no matter what position, or almost no matter what position, of the tool  100 , depending, as has been seen, on the size of the mounting region. Thus, by combining the possibility of rotation of the tool about the clamping band, with the possible inclination provided by the rotation of the jaws  103  as has been mentioned, the tool  100  can be directed in all directions in the space for a same final position of a clamping band  1 . 
     According to a first particular characteristic of the jaws, the jaws  103  of one of the legs  101 , comprises a lug  137  which appears in the drawings of the tool in cross-section and particularly in FIGS. 27 and 28, extending perpendicularly toward the jaw of the other leg  102  which is provided with a corresponding recess  138 , such that the lug  132  matches exactly the recess  138  when the two jaws  103  are brought together, as shown for example in FIGS. 22 and 23. Thus, when a clamping band  1  is pre-stressed on the positioning tool  100 , the legs  100  and  102  are brought together and it is possible to give to the clamping band  1  an inclination that it can vary substantially by more or less than 90° on opposite sides of the medial plane of the tool, so as to find the best position for application of the band. It is evident at this time that the operation of rotation of the pre-compressed clamping band between the jaws of the positioning tool will be made safe: the coaction of the lug  137  with the recess  138  rendering the two jaws  103  secured together during rotation, the clamping band  1  need no longer be freed from the jaws by undesirable twisting of said collar. 
     According to another particularly advantageous characteristic connected to the jaws  103 , the latter are provided with an automatic return mechanism, shown in FIGS. 34 and 35, toward a rest position corresponding to aligned gripping of the clamping bands, as the legs are unloaded. This return mechanism for the jaws  103  from an angular position of their medial axis xx′ to the left or right of the medial longitudinal axis of the heads yy′, from at most 90° up to the rest position in which the axis xx′ coincides with the axis yy′, consists in an elastomeric shaft  140  which is preferably cylindrical and held when it is at rest, along the axis yy′ of the heads, fixed on one hand and slidable on the other, to the interior of a head  141  secured to the head and passing through the rotative shaft  142  of the jaws when it is in rest position, which is to say when the axis xx′ and aligned with the axis yy′ of the head; this mounting of the shaft  140  through the shaft  142  of the jaw preferably permits not only holding said jaw on the head of the legs as shown in cross-section in FIG. 36, but also the angular resilient return force resulting from the transverse torsion to the left or right of the elastomeric shaft  140  deformed by the rotation shaft  142 , as shown in FIG. 35; a recess  143  in the head  141  of the head and surrounding the rotation shaft  142  is provided to absorb the deformation of the elastomeric shaft  140  when it is twisted. 
     Supplementally, the mounting of the jaws  103  with automatic return on the heads of the legs is extremely simple: the rotation shaft  142  of the jaws is centered in the head  141  of the head and aligned with the latter so that a resilient shaft  142  can be introduced through a hole extending axially from the distal end of the head to the leg and in such manner that the shaft  140  passes through a radial tunnel traversing the shaft  142  so as to be finally counterblocked by a simple ball  144  disposed before mounting in the head  141 ; a plate  145  is provided to counterblock the shaft  140  on the ball  144  as well as the assembly of the head by the single means of a screw  146  (FIG.  36 ). 
     According to a preferred construction of the tool  100 , with reference to FIG. 21, the casing  104  is constituted by two shells  104   a  that are preferably identical, of a plastic material shaped externally to serve as a gripping member for the tool  100 ; the two shells  104   a  are fixed facing each other by screw  147 ,  148  and  149  as well as by the axle  124  preferably used for the rotation of the trigger  123 , so as to be able to enclose on the one hand the two legs  101  and  102 , by being disposed on opposite sides of the plane which said legs form, a longitudinal groove  107  being provided on the internal surface of each shell to receive the ends of the articulation  53  of the legs preferably provided with roller bearings  108  so as to ensure their sliding between the front end  106  and rear end  105  of said grooves  107  serving as abutments, and to enclose on the other hand a metallic cage  150  comprising two flanges  150   a  and  150   b  preferably identical and mounted facing each other, at an equal distance thanks to interposed crosspieces  151  gripped between the screws  147 ,  148  and  149 ; this cage  150  thus delimits the opening of the casing  104  traversed by the two legs and supports all the fixed or turning abutments  111 ,  113 ,  116  against which come to bear the external edges  110 ,  109  of the legs as well as the elements forming the swinging mechanism. 
     Finally, and according to another secondary characteristic of the modification tending to facilitate the sliding of the legs  101  and  102  in the transverse direction relative to the plane that they form in all situations in which the legs are subjected to a left or right lateral force; to limit the friction at the opening of the casing  104  and more particularly against the flanges  150   a,  these latter are recessed to be able to receive a guide member  152  which comes to bear on the lateral surfaces of the legs  101  and  102 . The guide member, as shown in FIG. 21, can be a plate  152  made of a material with a low coefficient of friction, for example of silicone, sandwiched between the two lateral flanges  150   a  of the cage  150 , slightly overhanging in the direction of the lateral surfaces the legs  101  and  102 . 
     According to another embodiment, the guide member can be constituted by one or several rollers of parallel axes (not shown in the drawings), fixed in the thickness of the lateral flanges of the metallic cage  150  to come to bear against the lateral surfaces of the legs according to a generatrix perpendicular to the direction of their sliding. 
     The tool  100  as has been described in these different configurations, can be used according to FIGS. 17 to  20  which show in detail the general operation of the positioning tool  50  corresponding to the preceding embodiment, in cooperation with the dispenser  2  to carry out the gripping of a flexible pipe  12  on piping  13  by means of a clamping band  1 . 
     Of course, the improved tool  100  permits increasing the total control of the discharge of the clamping band  1 , and this even in a very crowded environment.