Coupling

Abstract

Coupling (1) for connecting an anchor (20) to a traction member (30), the anchor being provided with an elongated member (200) longitudinally delimited by a first end (202) and by a second end (204) provided with a fluke (2040); the first end being longitudinally delimited by a flat end (2020) provided with a connection hole transverse to the elongated member; the coupling comprising a shank (10) longitudinally delimited by a first portion (14) provided with a first fork (140) and by a second cylindrical portion (16); the first fork having a seat (1400) and a pivot pin (1402) arranged to house and rotatably constrain the first end; the second portion having a spherical cavity (160) delimited by an opening (162) engaged by a pin (164) having a cylindrical shaft (166); the opening comprising a first flat edge (1620) transverse to the longitudinal axis and comprises support means (1622) distributed for the cylindrical shaft extending in depth between two points (A, B) of the first edge.

Description

[0001] COUPLING

[0002] DESCRIPTION

[0003] The present invention relates to a coupling . In particular, the present invention refers to a coupling for connecting an anchor to an anchor windlass device . More in detail , the present invention refers to a coupling for connecting an anchor to an anchor windlass device through a traction member in a j ointed manner .

[0004] DESCRIPTION OF THE BACKGROUND ART

[0005] In the boat industry for some time now there has been the tendency to equip boats with increasingly sophisticated devices , capable of performing complex operations without requiring human intervention, both to solve the frequent di f ficulty of obtaining a full crew, above all in boats under 24 m, and to allow the crew to concentrate on operations that require them to carry out steps di fficult to outline in rigidly defined procedures .

[0006] Among these devices , the anchor windlass is the device that is mostly found installed at the bow on boats and in combination with a guide associated with the bow roller for the traction member, usually a chain, where the guide has the function of orienting the chain at the winch of the anchor windlass so as to prevent j amming of the chain and mal functioning of the winch, and the bow roller has the purpose of retaining the anchor during navigation or when the boat is moored at the quayside . Generally, the chain is connected to the eyelet of the end of the shaft through a shackle and the bow roller carries an idler wheel externally, the function of which is to limit friction during hoisting of the chain . One of the critical moments when the anchor is hoi sted occurs when the end of the shaft of the anchor sticks in the race of the wheel , due to a condition of dimensional interference between this end and the race of the wheel for known dimensional causes . When this occurs , human intervention is required to overcome the condition of sticking . On the other hand, to overcome this problem, particularly irksome when wishing to hoist the anchor quickly, for example due to a sudden change in the weather conditions while at anchor in a crowded bay, the patent TR 2007 06837 by the Turkish company "Boyut Makina Sanayi Ve Ticaret" proposes interposing a swivel coupling between the chain and the anchor, the features and the operation of which are clearly described in the text , with particular reference to the shape of the portion of the coupling, of the respective cylindrical shank and pin that engages one end of the shank in a ball j ointed manner and carries a first fork that houses the end link of the chain . The shank, externally cylindrical , has a diameter that approximates by default the dimensions of the race of the wheel and on one side has a seat for the ball head of the pin, where this seat is delimited by a circular end that carries a bill shaped abutment that introduces a condition of imbalance when the neck of the pin rests on the edge of the opening . On the other side , the shank has a second fork that , passed through transversely by a pivot pin, engages the eyelet of the anchor to allow stable connection and relative rotation of the anchor with respect to the shank . Moreover, on this side , and on the same side as the bill , the shank has a saddle member that protrudes beyond the extension of the body of the shank to externally surround on three sides the end of the shaft provided with the eyelet . This saddle member provides a supporting condition to the shaft of the anchor, when the shaft of the anchor is aligned with the shank, circumstance in which the rotation of the shank in the race of the wheel is facilitated with respect to the first fork, and produces correct angular positioning of the anchor with the end of the shaft oriented so as to correctly engage ( from a dimensional viewpoint ) the race of the wheel . This makes hoisting of the anchor until the chain has been completely reeled in and its stabili zation in the bow roller smooth .

[0007] With reference to this solution, it is easily understood that the apex of the bill , obtained in a spherical portion of constant thickness , represents a portion subj ected to particular stress in use due to the impacts that inevitably occur between bill and neck of the pin carrying the first fork when the anchor is free in the air during dropping and hoisting, a circumstance in which it can swivel freely with any orientation of the fluke , hence of the anchor shaft . I f the impact occurs when the anchor shaft is aligned with the shank, therefore when it is housed inside the saddle member, the load acting on the bill is maximum, given that the distance between the point in which the load is applied given by the anchor from the apex of the abutment is maximum, and consequently the apex can easily be chipped, flattened or prematurely deformed so as to have a concavity above all when the coupled anchor has a particularly large mass . Naturally, in these cases , sliding of the neck of the pin along the whole of the edge of the bill is compromised and the coupling must be replaced, a condition that during navigation far from boat equipment suppliers may not be easy and may compromise the implementation of navigation plans .

[0008] For the reasons described above , the problem of obtaining a swivel coupling that can be used to connect the anchor to the chain in a swivelling manner is currently unsolved, and represents an interesting challenge for the applicant , with the obj ect of changing the competitive scenario of this product sector .

[0009] In consideration of the situation described above , it would be desirable to have a coupling which, besides limiting and possibly overcoming the drawbacks typical of the state of the art illustrated above , is fabricated in such a way as to best exploit the mechanical features of the material of which it is made to be strong, durable and inexpensive , so as to set a new standard for these types of product .

[0010] SUMMARY OF THE PRESENT INVENTION

[0011] The present invention relates to a coupling . In particular, the present invention refers to a coupling for connecting an anchor to an anchor windlass device . More in detail , the present invention refers to a coupling for connecting an anchor to an anchor windlass device through a traction member in a j ointed manner .

[0012] The aforesaid drawbacks are solved by the present invention according to at least one of the appended claims .

[0013] According to some embodiments of the present invention, there is provided a coupling for connecting an anchor to a traction member, said anchor being provided with an elongated member longitudinally delimited by a first end and by a second end provided with a fluke; said first end being longitudinally delimited by a flat end provided with a connection hole transverse to said elongated member; said coupling comprising a shank extending according to a longitudinal axis and is longitudinally delimited by a first portion provided with a first fork and by a second cylindrical portion; said first fork having a seat and a pivot pin arranged to house and rotatably constrain said first end around an axis transverse to said longitudinal axis ; said second portion having a spherical cavity delimited by a circular opening; said shank carrying a pin provided with a spherical head that engages said cavity and a cylindrical shaft that engages said opening with clearance ; said opening being externally delimited by a first flat edge transverse to said longitudinal axis and comprises support means distributed for said cylindrical shaft extending in depth between two points of said first flat edge arranged on the same side with respect to said longitudinal axis .

[0014] According to an embodiment as described above , said support means comprise a second longitudinal convex edge that shares a portion of said cavity .

[0015] According to an embodiment as described above , said second edge is shaped transversely to said longitudinal axis similarly to a rectilinear chord between said two points of said first flat edge .

[0016] According to an embodiment as described above , said second edge has a concave portion in a given respective position facing said cylindrical shaft .

[0017] According to an embodiment as described above , said concave portion extends between said two points of said first flat edge .

[0018] According to an embodiment as described above , said concave portion comprises a recess with a curvature smaller than said cylindrical shaft .

[0019] According to an embodiment as described above , said concavity of said second edge is shaped similarly to an arc with a variable or circular curvature eccentric with respect to said longitudinal axis .

[0020] According to an embodiment as described above , said first end and said shank are provided with a limiting device of a clockwise and counter-clockwise rotation of said elongated member with respect to said first fork inside said seat around said transverse axis , with the purpose of delimiting an admissible angular range for a rotation of said elongated member with respect to said shank .

[0021] According to an embodiment as described above , said limiting device comprises a tooth machined eccentrically with respect to said transverse axis in said first end and an abutment member carried by said first fork inside said seat ; said abutment member being shaped and positioned so as to determine, in use, a condition of contact with said tooth when said elongated member is aligned with said longitudinal axis of said shank in a contact area of given geometrical shape and when said elongated member is rotated with respect to said longitudinal axis by a given angle .

[0022] According to an embodiment as described above , said tooth is substantially V-shaped and externally has a first abutment surface ; said abutment member being delimited by a second abutment surface shaped so as to be tangent to said first surface when, in use , said first end is aligned with said shank .

[0023] According to an embodiment as described above , said pin provided with a spherical head has a free end that carries a second fork, said second fork being arranged to couple with said traction member .

[0024] Any further embodiments of the present invention are defined by the claims .

[0025] BRIEF DESCRIPTION OF THE FIGURES

[0026] Further features and advantages of the coupling according to the present invention will be more apparent from the following description, provided with reference to the accompanying figures , which illustrate at least one example of non-limiting embodiment thereof , in which identical or corresponding parts of anchor and interface are identi fied by the same reference numbers . In particular : - Fig. 1 is a schematic perspective view, with parts not represented for clarity, of a first preferred embodiment of a coupling according to the present invention for connecting an anchor to a traction member;

[0027] - Fig. 2 is a schematic perspective view of an anchor for the coupling of Fig. 1;

[0028] - Fig. 3 is a side elevation view of an upper portion of Fig. 2 in enlarged scale with parts removed for clarity;

[0029] - Fig. 4 is a schematic perspective view of Fig. 3;

[0030] - Fig. 5 is a schematic perspective view of Fig. 1 rotated axially in counter-clockwise direction;

[0031] - Fig. 6 is a longitudinal median section of Fig. 5;

[0032] - Fig. 7 is a front view of a detail of Fig. 6 in enlarged scale and with parts removed for clarity;

[0033] - Fig. 8 is a flipped view of Fig. 6;

[0034] - Fig. 9 is a view of a detail extracted from Fig. 8 in enlarged scale;

[0035] - Fig. 10 is a side elevation view of a detail of Fig. 5 represented rotated and with parts removed for clarity;

[0036] - Fig. 11 is a view rotated through 180° with respect to Fig. 10;

[0037] - Fig. 12 is an overall view of a coupling and of an anchor according to the present invention;

[0038] - Figs. 12a and 12b are views of a portion of Fig. 12 represented in two different operating configurations;

[0039] - Fig. 13 illustrates the detail of Fig. 9 rotated to highlight further construction details;

[0040] - Fig. 14 reproduces the front view of Fig. 7;

[0041] - Fig. 15 is a front view of a second preferred embodiment of Fig. 7; and

[0042] - Fig. 16 is a front view of a third preferred embodiment of Fig . 7.

[0043] DETAILED DESCRIPTION OF THE PRESENT INVENTION Before describing in detail the preferred embodiments of the present invention, or details thereof , it is useful to speci fy that the relevant scope of protection is not limited to the particular embodiments described hereunder . The disclosure and the description in the present document are illustrative and explicative of one or more currently preferred embodiments and variants , and it will be apparent to those skilled in the art that various changes may be made to the design, organi zation, operating order, operating means , structures of the equipment and position, to the methodology and use of mechanical equivalents without departing from the spirit of the invention .

[0044] Moreover, it must be understood that the accompanying figures have the obj ect of clearly illustrating and disclosing currently preferred embodiments to a person skilled in the art , but are not drawings illustrating how these embodiments should be executed in reality or true representations of final products ; on the contrary, these figures may comprise conceptual views simpli fied to facilitate understanding or to allow a simpler and quicker explanation to be provided . Moreover, the dimensions and the relative arrangement of the components may di f fer from those shown and still operate within the spirit of the invention .

[0045] Further, it will be understood that various directions , such as "upper" , " lower" , " left" , " right" , " front" , "back" and so forth, are executed only with respect to the explanation in combination with the drawings and that the components can be oriented di f ferently, for example during transport and production, as well as during operation . As many di f ferent and distinct embodiments may be implemented within the scope of the concepts taught herein, and as there are many modi fications that may be made to the embodiments described herein, it must be understood that the details provided hereunder are to be interpreted as illustrative and non-limiting of the spirit of the invention .

[0046] With reference to Fig . 1 , the reference number 1 indicates , as a whole , a coupling provided for connecting an anchor 20 , visible in Fig . 2 , to a traction member 30 , where the anchor 20 is provided with an elongated member, or shaft , 200 longitudinally delimited by a first free end 202 and by a second end 204 provided with a fluke 2040 . Without limiting the scope of the present invention, the traction member 30 can be a chain or a cable made of textile material . For convenience and for greater familiarity with what is usually found on boats , here and hereunder the term chain must be understood as being equivalent to the expression "traction member" and in the accompanying drawings the same reference number 30 is associated with both to facilitate understanding of how the invention of this application may be implemented .

[0047] Further, it may be useful to speci fy that the following is independent of the type of construction of the anchor 20 , and of the fluke 2040 and, more generally, of how the anchor 20 is fabricated, by pressing, by welding of simple elements or of portions of pressed sheet metal .

[0048] With reference to Fig . 3 , the first end 202 is longitudinally delimited by a flat end 2020 provided with a connection hole 2022 the axis of which is transverse to the flat end 2020 .

[0049] With particular reference to Figs . 1 , 5 and 7 , the coupling 1 comprises a cylindrical shank 10 extending according to a respective longitudinal axis 12 and is longitudinally delimited by a first portion 14 provided with a first fork 140 and by a second portion 16 . The first fork 140 has a seat 1400 , delimited by a bottom wall 141 transverse to the longitudinal axis 12 on the side of the cavity 160 , and a pivot pin 1402 arranged respectively to house and rotatably constrain the first end 202 around a transverse axis 1402A of the pivot pin 1402 arranged transverse to the longitudinal axis 12 .

[0050] With particular reference to Fig . 6 , the second portion 16 has a spherical cavity 160 that measures a first given diameter and is delimited on the opposite side to said first portion 14 by a substantially circular opening 162 that measures a second given diameter ; the second portion 16 further comprises a pin 164 , provided with a spherical head 1640 that engages the cavity 160 in a form- fitting manner . The pin 164 has a cylindrical shaft 166 that engages the opening 162 with clearance . In particular, with reference to Fig . 7 , the opening 162 is externally delimited by a first edge 1620 that lies on a flat surface transverse to the longitudinal axis 12 and comprises a support element 1622 distributed for the cylindrical shaft 166 of the pin 164 , where the support element 1622 extends rectilinearly between two points A and B of the first flat edge 1620 , arranged on the same side with respect to the longitudinal axis 12 and has , point by point , a longitudinal extension, in the sense that it extends along the longitudinal axis 12 . In particular, the section A-B is geometrically a chord for the circular portion of the edge that delimits the opening 162 from the ins ide . In particular, the support element 1622 is at a distance from the longitudinal axis 12 in each point by a length of greater extension than a radius of the cylindrical shaft 166 of the pin 164 , so as to allow the cylindrical shaft 166 of the pin 164 to be arranged inclined towards the outside in each configuration taken with respect to the longitudinal axis 12 . As is more apparent in Fig . 14 , the radius of the pin 164 has a si ze that approximates by default the distance between the longitudinal axis 12 and the first face 1620.

[0051] With particular reference to Figs . 8 and 9 , the support element 1622 for the cylindrical shaft 166 of the pin 164 is delimited by a second convex edge 16220 extending longitudinally which supports the cylindrical shaft 166 and shares a spherical portion of the cavity 160 .

[0052] With particular reference to Figs . 2 , 4 , 6 , 9 , 11 and 12 , the first end 202 of the anchor 20 is provided with a V- shaped tooth 2024 obtained in the first end 202 eccentrically with respect to the transverse axi s 1402A. In particular, the tooth 2024 is provided externally with a first abutment surface 20240 parallel to the axis of the hole 2022 ( Figs . 4 , 6 , 11 , 12 ) . Moreover, the shank 10 comprises an abutment member 1404 carried by the first fork 140 inside the seat 1400 . The abutment member 1404 is shaped and positioned so as to determine, in use , a condition of contact with the first abutment surface 20240 of the tooth 2024 when, in use , the shaft 200 of the anchor 20 is aligned with the longitudinal axis 12 of the shank 10 , or also when only its first end 202 is aligned with the longitudinal axis 12 of the shank 10 when the first end 202 is the only rectilinear part of the shaft 200 of the anchor 20 . The first abutment surface 20240 has a first apical part 20240 ' and a second part 20240 ' ' that descends towards the second end 204 of the shaft 200 of the anchor 20 , where it is useful to speci fy that both parts are positioned on the same side with respect to the abutment member 1404 and, in use , to the fluke 2040 .

[0053] Moreover, with particular reference to Figs . 6 , 11 and 12 , the abutment member 1404 can consist of a strip of the shank 10 , which for practicality is indicated with the same reference number 1404 ; this strip 1404 laterally closes the seat 1400 and is delimited transversely by a respective edge 1406 and internally by a flat abutment face 1408 . Therefore , the strip 1404 , and in particular the respective edge 1406 , is suitable to act as abutment for the second part 20240 ' ' of the first abutment surface 20240 . With regard to the description above , the assembly of the first end 202 and of the shank 10 , in particular of the tooth 2024 and of the abutment member 1404 , through the first part 20240 ' and second part 20240 ' ' of the first abutment surface 20240 on one side , and the face 1408 and the edge 1406 of the strip 1404 on the other, define a limiting device 2000 ( Fig . 12 and Figs . 12a e 12b ) of the relative clockwise and counter-clockwise rotation of the anchor 20 with respect to the shank 10 of the coupling 1 around the pin 1402 . Therefore , the function of the limiting device 2000 is to be arranged to delimit an admissible angular operating range for the relative rotation of the shaft 200 of the anchor 20 with respect to the first fork 140 of the shank 10 of the coupling 1 inside the respective seat 1400 around the transverse axis 1402A of the pivot pin 1402 . This angular range is defined by two limit positions , in both of which the tooth 2024 contacts the strip 1404 and the dimensions of this angular range are a function of the shape of the tooth 2024 and of the edge 1406 of the strip 1404 and of the respective positions on the first end 202 and with respect to the seat 1400 .

[0054] For the particular dimensional choices , and for the obj ect for which the invention was primarily conceived, it is particularly relevant to add that the limiting device 2000 enables the condition of alignment of the first end 202 of the anchor 20 with the longitudinal axis 12 of the shank 10 , when the tooth 2024 abuts with the face 1408 , and the condition in which the first end 202 / the shaft 200 is rotated by a given angle in the opposite direction with respect to the longitudinal axis 12 , in which the part 20240 ' of the first surface 20240 is abutting with the edge 1406 of the strip 1404 , suitably bevelled to minimi ze the local contact pressure between the first end 202 and the strip 1404 . The amplitude of this angle depends on speci fic dimensions defined for the strip 1404 , in terms of longitudinal position of the edge 1406 and distance of the face 1408 with respect to the longitudinal axis 12 . The inclination of the first flat abutment surface 20240 is such that , in use , contact between the first flat abutment surface 20240 of the tooth 2024 and the flat face 1408 of the abutment member 1404 corresponds and extends on a substantially rectangular flat surface , the area of which approximates the area of the flat portion 20240 .

[0055] Moreover, the present invention also includes the case in which, due to di f ferent shapes of the tooth 2024 and of the abutment member 1404 , the contact area between the outer surfaces of the tooth 2024 and of the abutment member 1404 extends on an area with geometric shape depending on the shape of the areas arranged for mutual contact of the tooth 2024 and of the abutment member 1404 ; in particular, this geometric shape can be a line , a rectangular area or an area delimited by a closed curved line of another shape , but always has a component in the direction parallel to the axis of the pivot pin 1402 . With particular reference to Figs . 1 and 6 , the pin 164 is provided with a spherical head 1640 and has a free end on the opposite side to said spherical head 1640 that supports a second fork 168 arranged to couple with the traction member 30 . Use of the coupling 1 in combination with the anchor 20 is easily understood from the description above and does not require further explanation . Moreover, with speci fic reference to Fig . 1 , it may be useful to speci fy that upon triggering the rotation step of the shaft 200 of the anchor 20 during the movement of the shank towards the wheel of the bow roller, when the cylindrical shaft 166 of the pin 164 is supported on the second edge 16220 , normally striking it , the condition of support is distributed on a part T of the first portion 14 which extends in depth both longitudinally, in the sense that it involves a longitudinal slice of shank 10 which starts from the first edge 1620 and ends in the cavity 160 , and transversely with respect to the longitudinal axis 12 between the points A and B, as can be seen in Figs . 8 , 9 and 13 . This makes it possible to produce a shank 10 in which the width of the resistant section in the point of impact has a thickness that is approximately double the thickness of the material in the area below, relating to the ball j oint . For this reason, the features of the material with which the support element 1622 is fabricated are better exploited from a mechanical viewpoint with respect to the case of the bill shaped abutment of the patent TR ' 837 , where the thickness of the material at the bill where the impact of the shaft 166 is concentrated in longitudinal and transverse direction is substantially constant , reproducing the shape of a spherical cap sector, therefore providing insuf ficient support at the apex of the bill which, for this reason, is weak and susceptible to plastic damage and / or to chipping . Further, in this case , due to the way in which the support element 1622 extends between the points A and B, the variation of speed and of acceleration of the movement of the cylindrical shaft 166 of the pin 164 proceeding from the centreline of the support element 1622 towards the ends A or B is lower, and therefore less energy is associated with the impact with the edges of the support element 1622 , end of stroke of the movement of the cylindrical shaft 166 of the pin 164 at the end of the rotation step of the shaft 200 of the anchor 20 during the movement of the shank 10 towards the wheel of the bow roller .

[0056] Finally, it is clear that modi fications and variations can be made to the coupling 1 described and illustrated herein, without departing from the scope of protection of the present invention .

[0057] For example , with particular reference to Fig . 15 , the coupling 1 , the respective support element 1622 , and hence the respective second edge 16220 , has a concave portion 16222 which extends parallel to the longitudinal axis 12 in a respective given position facing the cylindrical shaft 166 of the pin 164 . Moreover, for reasons of symmetry, in the maj ority of cases , the concave portion 16222 is equidistant from the two end points A and B . In this case , it is useful to speci fy that the concave portion 16222 comprises a recess 16224 with a curvature smaller than the cylindrical shaft 166 of the pin 164 in a respective longitudinal portion facing the recess 16224 .

[0058] According to Fig . 16 , the concave portion 16222 has an extension increased and extending between the points A and B and, i f considered useful , can be shaped similarly to an arc of circle eccentric with respect to the longitudinal axis 12 or with variable curvature , di f ferent point by point , for example to determine speci fic speed and acceleration profiles point by point .

[0059] Moreover, it is useful to speci fy that the opening 162 can be modi fied placing the support element 1622 at a distance from the longitudinal axis 12 identical to or smaller than the radius of the cylindrical shaft 166 of the pin 164 , so as to constrain the cylindrical 166 of the pin 164 to be positioned inclined in a given way based on speci fic needs dictated by the field of use of the coupling 1 , which therefore refer to embodiments o f the invention included in the scope of protection of the present invention .

[0060] In the claims , any reference sign placed between parentheses shall not be construed as limiting the claim . The word " comprising" does not exclude the presence of other elements or steps besides those listed in a claim . Moreover, the term " a" or " an" , as used in this context , is defined as one or more than one . Moreover, the use of introductory expressions such as " at least one" and "one or more" in the claims shall not be construed to imply that the introduction of another claim element identi fied using the indefinite article "a" or " an" limits any particular claim in which this claim element appears singularly, even when thi s claim comprises the introductory phrases "one or more" or " at least one" and the indefinite article " a" or " an" . The same applies to the use of the definite article . Unless otherwise stated, terms such as " first" and " second" are used to arbitrarily distinguish between the elements these terms describe . Therefore , these terms are not necessarily intended to indicate temporal or other prioriti zation of these elements . The mere fact that certain measures are recited in mutually di f ferent claims does not indicate that a combination of these measures cannot be used to advantage .

Claims

CLAIMS1. Coupling (1) for connecting an anchor (20) to a traction member (30) , said anchor (20) being provided with an elongated member (200) longitudinally delimited by a first end (202) and by a second end (204) provided with a fluke (2040) ; said first end (202) being longitudinally delimited by a flat end (2020) provided with a connection hole transverse to said elongated member (200) ; said coupling (1) comprising a shank (10) extending according to a longitudinal axis (12) and is longitudinally delimited by a first portion (14) provided with a first fork (140) and by a second cylindrical portion (16) ; said first fork (140) having a seat (1400) and a pivot pin (1402) arranged to house and rotatably constrain said first end (202) around an axis (1402A) transverse to said longitudinal axis (12) ; said second portion (16) having a spherical cavity (160) delimited by a circular opening (162) ; said shank (10) carrying a pin (164) provided with a spherical head (1640) that engages said cavity (160) and a cylindrical shaft (166) that engages said opening (162) with clearance; characterized in that said opening (162) is externally delimited by a first flat edge (1620) transverse to said longitudinal axis (12) and comprises support means (1622) distributed for said cylindrical shaft (166) extending in depth between two points (A, B) of said first flat edge (1620) arranged on the same side with respect to said longitudinal axis (12) .

2. The coupling according to claim 1, characterized in that said support means (1622) comprise a second longitudinal convex edge (16220) that shares a portion of said cavity (160) .

3. The coupling according to claim 2, characterized in that said second edge (16220) is shaped transversely to saidlongitudinal axis (12) similarly to a rectilinear chord between said two said points (A, B) of the said first flat edge (1620) .

4. The coupling according to claim 3, characterized in that said second edge (16220) has a concave portion (16224) in a given respective position facing said cylindrical shaft (166) .

5. The coupling according to claim 4, characterized in that said concave portion (16222) extends between said two points (A, B) of the said first flat edge (1620) .

6. The coupling according to claim 5, characterized in that said concave portion (16222) comprises a recess (16224) with a curvature smaller than said cylindrical shaft (166) .

7. The coupling according to claim 6, characterized in that said concavity of said second edge (16220) is shaped similarly to an arc with a variable or circular curvature eccentric with respect to said longitudinal axis (12) .

8. The coupling according to any one of claims 1-7, characterized in that said first end (202) and said shank (10) are provided with limiting means (2000) of a clockwise and counter-clockwise rotation of the said elongated member (200) with respect to said first fork (140) inside said seat (1400) around said transverse axis (1402A) , with the purpose of delimiting an admissible angular range for a rotation of said elongated member (200) with respect to said shank (10) .

9. The coupling according to claim 8, characterized in that said limiting means (2000) comprise a tooth (2024) machined eccentrically with respect to said transverse axis (1402A) in said first end (202) and an abutment member (1404) carried by said first fork inside said seat; said abutment member (1404) being shaped and positioned so as to determine, in use, a condition of contact with said tooth (2024) when said elongated member (200) is aligned with said longitudinalaxis (12) of the said shank (10) in a contact area of given geometrical shape and when said elongated member (200) is rotated with respect to said longitudinal axis (12) by a given angle.

10. The coupling according to claim 9, characterized in that said tooth (2024) is substantially V-shaped and externally has a first abutment surface (20240) ; said abutment member (1404) being delimited by a second abutment surface (1408) shaped so as to be tangent to said first surface (20240) when, in use, said first end (202) is aligned with said shank (10) .

11. The coupling according to any one of the preceding claims, characterized in that said pin (164) provided with a spherical head (1640) has a free end that carries a second fork (168) arranged to couple with said traction member (30) .

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