WO2012143474A1 - Connection system for attaching a carrier device - Google Patents

Abstract

Connection system (1) for attaching a carrier device to a hitch (2) having a terminal coupling part comprising a ball (3) and a neck (4), the system (1) comprising an internal cavity (10) open at least at an open end (23) and able to accept the ball (3) of the terminal part, characterized in that the cavity (10) comprises an insertion portion (12), at the free end of which the open end (23) is arranged, and an attachment portion each able to accept the ball (3), and in that the attachment portion (32) comprises a stop surface (29) configured to adopt alternately, by means of rotation of said cavity (10), an inactive position in which the stop surface (29) can be kept away from the terminal coupling part (3, 4) and an active position in which the stop surface (29) can be applied against the terminal coupling part (3, 4). Application to the connection of a carrier device at the rear of a motor vehicle.

Description

 "Connection system for attaching a carrying device"

The invention relates to a connection system for attaching a carrying device to a hitch of a motor vehicle, its mounting method on the terminal attachment part of the hitch and the carrying device of least one element disposed at the rear of the vehicle comprising such a connection system.

The invention will find application for various types of carrying device for the transport of one or more elements in the rear of a motor vehicle, the carrying device being secured to the terminal attachment part of the coupling present at the rear of said vehicle for traction of an auxiliary element. Advantageously, the carrying device is more particularly a bicycle carrier. The term "carriage" must however be understood in the broadest sense of any device capable of receiving a load to be carried for transport by means of the equipped vehicle. Any device connectable to the vehicle through the invention falls within this framework. Such a hitch is frequently a hitch whose attachment end portion is substantially vertical and consists of a ball and a neck, the ball and the neck being fixed on the rear of the chassis of the motor vehicle through an angled arm. In what follows, it will be taken as an example a ball hitch to illustrate the hitch in the rear of a motor vehicle.

 For example, for the traction of an auxiliary element such as a caravan or a trailer by a motor vehicle, it is known to use a ball hitch, the ball of such a hitch being surrounded, in the towed position of the vehicle. auxiliary element, by a bowl secured to the body of said auxiliary element. Such a connection is called a ball or ball-sphere connection and completely links the vehicle with the element to be translated in translation but leaves them free in a limited way in rotation. This connection therefore comprises three degrees of connection corresponding to the three possible translations, these three degrees being blocked. The connection also comprises three degrees of freedom in rotation between the motor vehicle and the element to be towed, these degrees of freedom corresponding to roll, pitch and yaw. These degrees of freedom in rotation are, however, limited by the shape of the element to be towed or by the interference between the element to be towed and the motor vehicle.

 Such a hitch ball comprises a spherical head called ball on platinum or ball gooseneck. This spherical head is extended by an angled support connecting it with the chassis of the motor vehicle. The junction of the spherical head and the crank support is designated by the neck of the hitch ball.

As a use other than that of traction of an auxiliary element of the type mentioned above, it is known to use such a ball hitch for fixing a suspension carrying device at the rear of the motor vehicle, it is thus known various connection systems of such a carrying device to a hitch ball forming the end portion of attachment of the hitch. Conventionally, the connection system comprises a housing consisting of an arcuate portion intended to cooperate with the upper part of the hitch ball. These systems require clamping means of said ball in its housing. The clamping means are mobile and block the lower part of the hitch ball and generate several bearing surfaces on the ball, including a recovery of gravity.

 These connection systems, however, do not allow easy implementation on the ball of the hitch. In many cases, it is necessary to perform several operations for its mounting on the hitch and there are risks that the clamping between connection system and hitch is not performed correctly. However, unwanted residual mobility of the connection system with respect to the motor vehicle may be harmful, in particular by damaging the vehicle or the associated carrying device during shocks between them.

 The problem underlying the present invention is to provide a connection system between a carrying device and the terminal attachment part of a hitch at the rear of a motor vehicle which increases the reliability of the connection while being easy to set up.

 To achieve this objective, there is provided according to the invention a connection system for fixing a carrying device on a hitch having a terminal portion comprising a ball and a collar, the system comprising an internal cavity open to at least one open end adapted to receive the ball of the end portion characterized in that the cavity comprises an insertion portion, at the free end of which is arranged the open end, and a fixing portion each suitable to receive the ball, and in that the fixing portion comprises a stop surface configured to take alternately by rotation of said cavity, preferably around the terminal attachment portion, an inactive position in which the stop surface is adapted to be moved away from the terminal attachment part and an active position in which the stop surface is able to be applied against the part t anchorage.

In another aspect, the invention relates to a connection system for attaching a carrying device to a hitch having a terminal fastening portion comprising a ball and a neck, the system comprising an internal cavity open to at least one end emerging and adapted to receive the ball of the end portion characterized by the fact that the cavity comprises an insertion portion, at the free end of which is arranged the emergent end and a fastening portion each adapted to receive the ball, and that the system comprises a groove adapted to allow the passage of the neck and having at least a first portion extending at the insertion portion and a second portion extending at the attachment portion.

 The present invention allows a facilitated implementation of the connection system ensuring effective and safe positioning of the system on the terminal portion of the hitch.

 According to another aspect of the invention, the connection system for attaching a carrying device to a hitch having an attachment end portion comprising a ball and a neck, the system comprising an internal cavity open to at least one open end and adapted to receive at least the ball of the end portion characterized in that the cavity comprises an insertion portion, a fixing portion each adapted to receive at least the bou le and q ue the com com takes a ra longitudinally in ure configured to ensure the sliding of at least the neck between the insertion portion and the fixing portion.

 Advantageously, the sliding is along an axis perpendicular to the longitudinal axis of the end portion. In this case, the sliding is a translation. Sliding is generally understood also as the movement of one part relative to another. Sliding can be a rotation alone.

According to another aspect of the invention, a connection system for attaching a carrier ispositif to a hitch having a terminal attachment portion, the system comprising an internal cavity open at an open end and adapted to receive said end portion during the introduction of the cavity around said portion characterized in that this cavity has an insertion portion and an attachment portion relative to said coupling portion, the system comprises a groove, longitudinal, for the passage of the neck of the end portion of the hitch, out of the connection system, said groove having a first portion associated with the second insertion portion and a portion associated with the fixing portion, advantageously the first and second groove portions forming a non-zero angle therebetween so that in the fastening portion at least one edge of said first portion forms a first bearing surface of the system against said end portion and in that the cavity has a bottom portion, at least a bearing portion of the bottom portion of the cavity forming a second bearing surface of the system against said end portion.

 The technical effect obtained is an implementation of the connection system in which the actions of the first and second bearing surfaces are opposite, which ensures a self-tightening of the system on the terminal attachment part of the coupling. This self-tightening does not require the use or the addition of auxiliary mounting parts and is done automatically by the action of the first and the second support surface conjugate and complementary during the tilting of the connection system and its cavity relative to the terminal part of the coupling.

 The system according to the invention may additionally have at least optionally any of the following characteristics:

 the stop surface is able to be applied in the active position against at least a portion of the neck,

 the fixing portion comprises a fixing opening extending the open end of the insertion portion and forming a non-zero angle with the mouth of the open end,

 the fastening aperture is smaller than that of the emergent end so as to maintain the ball in the cavity,

 it comprises a locking surface that is movable relative to the cavity between an application position against the terminal attachment part and a retracted position,

 the locking surface is formed on a lever arm capable of allowing the locking surface to be applied against the ball of the terminal end portion,

 it comprises a blocking surface arranged at least in the insertion portion,

the locking surface is at least diametrically opposed to the locking surface the blocking surface has an annular shape and whose axis of symmetry is adapted to be aligned with a diameter of the ball that can be positioned in the fastening portion,

 - It comprises a groove, at least a portion of which forms the fastening opening, adapted to allow passage of the neck and having at least a first portion extending at the insertion portion and a second portion extending at the fixing portion

 the groove has a width smaller than the largest dimension of the ball,

 the cavity has a sheath shape,

 the first part of the groove is oriented in a plane not parallel to that of the open end,

 the groove has a rectilinear section,

 the first part and the second part of the groove form a non-zero angle between them,

 the groove is configured to guide the end portion of the hitch in a direction perpendicular to the longitudinal axis of the end portion,

at least one first bearing surface adapted to be in contact with the end portion of the hitch is formed by the cavity at its insertion portion on either side of the groove,

 at least one second bearing surface adapted to be in contact with the end portion is formed by the cavity in the fixing portion at a bottom portion advantageously so that the first bearing surface and the second surface of support cause an automatic locking of the cavity with respect to the terminal part,

 the bottom portion comprises a metal reinforcement able to be in contact with a part of the neck,

 it comprises a platform extending from one of these ends and whose longitudinal plane forms an acute angle, preferably 30 to 70 °, preferably 45 °, with the longitudinal axis of the cavity.

a third bearing surface is formed by the cavity in the fixing portion at a zone opposite to the groove, the third bearing surface is movable between an application position on the end part and a retracted position,

 the system comprises a third bearing surface acting on the free end of the terminal attachment part of the hitch,

 the third bearing surface is formed by a pivotable movable piece about an axis of articulation transverse to said system, the movable part carrying a tip being able to be pressed against the free end of the terminal attachment part of the coupling,

 a lever is provided for positioning the tip of the movable piece against the free end of the terminal coupling portion of the hitch.

 The present invention also relates to a device for carrying one or more elements at the rear of a vehicle, characterized in that it comprises such a connection system.

 Advantageously, the carrying device is able to carry one or more bicycles.

 The invention also relates to an assembly comprising a ball hitch with such a connection system or with such a carrying device, the terminal attachment part of the hitch being substantially vertical and comprising a ball connected by a collar to the complement to the end part in the form of an angled arm.

 Advantageously, the groove has a vertical plane of symmetry.

 Advantageously, the first portion and the second portion of the groove form a non-zero angle between them in a vertical plane.

 Advantageously, the cavity and the groove are configured to create a sliding fit with the end portion of the hitch.

 Advantageously, the first bearing surface of the system is applied at least against a portion of the ball facing the open end of the cavity and the second bearing surface of the system is applied against at least a portion of the neck. vis-à-vis the bottom portion.

Advantageously, a shoulder is provided between the neck and the bent arm of the coupling, advantageously this shoulder protruding transversely of at least a portion of the perimeter of the neck. Advantageously, in the fixing position of the system with the hitch, the shoulder abuts against the portion of said groove opposite the cavity.

 Advantageously, the ball of the coupling comprises, at its apex forming the free end of the end portion of attachment, a flat.

 The invention also relates to a vehicle, particularly an automobile, comprising at its rear part such an assembly.

 The invention relates to a method of blocking a connection system as described above characterized in that it comprises the following steps:

 inserting said end portion into the insertion portion of the cavity,

 - Rotation of the connection system causing a placement of the terminal attachment portion in the fixing portion of the cavity and an automatic locking of the cavity relative to the terminal portion of attachment.

 Advantageously, the rotation is carried out by the weight exerted at a distance from the center of gravity of the ball by a platform extending from one of these ends from the connection system.

 Advantageously, the rotation is performed on an angular sector between 25 and 50 °, preferably 25 to 30 °.

 Advantageously, the method has a locking step of the connection system performed by applying a locking surface on the ball of the terminal attachment part.

 In another aspect, the invention relates to a method of blocking a connection system characterized in that it comprises the following steps:

 inserting said end portion into the insertion portion of the cavity,

 - Sliding of the connection system causing a displacement of the end portion of attachment in the fixing portion of the cavity.

According to another aspect, the invention relates to a method for locking a connection system on the end attachment part of a hitch disposed at the rear of a vehicle, said system comprising an internal cavity open at an open end. and able to receive said terminal portion, this cavity having an insertion portion and an attachment portion with respect to said attachment end portion and a bottom portion, the cavity including a longitudinal groove for passage from the neck to the end portion of the hitch out of the connection system, said groove having a first portion associated with the insertion portion and a second portion associated with the attachment portion, the first and second groove portions preferably forming a non-zero angle therebetween, the method comprising the following steps:

 sliding of the system cavity around said end portion, until said end portion is in the insertion portion of the cavity,

 - Tilt of the connection system causing a passage of the end portion of attachment in the fixing portion of the cavity, the tilt causing an automatic locking of the cavity relative to the end portion of attachment by support, the side facing the open end, at least one edge of the first part of the groove against the end portion of attachment and, on the other side opposite said end, at least a bearing portion of the portion of bottom of the cavity against said end portion.

 Advantageously, the method comprises a tilting of the cavity around the terminal end portion resulting in an automatic locking of the cavity relative to the end portion of attachment.

 Advantageously, the tilting is achieved by the weight exerted at a distance from the center of gravity of the ball by a platform extending from one of these ends from the connection system.

 Advantageously, the tilting takes place between a position where the longitudinal axis of the cavity extends substantially horizontally and a position in which the longitudinal axis is inclined by approximately 45 ° with respect to the horizontal.

Advantageously, the method has a step of locking in rotation of the connection system around the longitudinal axis of the end portion of attachment made by applying a bearing surface of the cavity on the free end of said end portion. . Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the accompanying drawings given as non-limiting examples.

 Figures 1 to 4 illustrate a first variant of the invention.

 FIG. 1 is a schematic representation of a perspective top view of a connection system according to the present invention,

- Figure 2 is a schematic representation according to the present invention of a longitudinal section of a connection system according to the present invention, the connection system has not yet been introduced around the terminal portion of attachment of the coupling,

 FIG. 3 is a diagrammatic representation according to the present invention of a longitudinal section of a connection system according to the present invention, the connection system having been introduced around the terminal attachment part of the hitch in its position. fastening by tilting the system relative to said hitch,

 FIG. 4 is a schematic representation according to the present invention of a longitudinal section of a connection system according to the present invention, the connection system having been introduced around the terminal attachment part of the hitch in its position. fastening by tilting the system relative to said hitch and locking in rotation of the system about the longitudinal axis of the end portion of the hitch having been performed.

 Figures 5 to 12 illustrate a second variant of the invention. Figures 6 and 10 correspond to a kinematic mounting system on the end portion of the hitch.

 FIG. 5 is a perspective view of the connection system,

FIG. 6 is a schematic representation of a longitudinal section of the connection system according to FIG. 5, the terminal attachment part of the coupling having not yet been introduced into the connection system;

FIG. 7 is a schematic representation of a longitudinal section of the connection system according to FIG. 5, the terminal portion attachment of the hitch having been introduced into the connection system, the stop surface being in the inactive position,

 FIG. 8 is a diagrammatic representation of a longitudinal section of the connection system according to FIG. 5, the connection system having pivoted around the terminal attachment part of the hitch, the stop surface being in the active position; ,

 FIG. 9 is a schematic representation of a longitudinal section of the connection system according to FIG. 5, the connection system being pre-tightened,

 FIG. 10 is a schematic representation of a longitudinal section of the connection system according to FIG. 5, the connection system being locked by the locking surface,

 FIG. 11 is a view from below of the connection system without a terminal end portion,

 FIG. 12 is a view from below of the connection system, the terminal attachment part being in the fixing position,

 In what follows the terms lower and upper will refer to the position occupied by an element of the connection system when it is mounted on the end portion of attachment of the hitch, said end portion extending substantially vertically in a fixed position on the chassis of a vehicle that can be an automobile or not.

 Referring to FIGS. 1 to 4 and to FIGS. 5 to 12, there is shown a connection system 1 adapted to be mounted on the terminal attachment end portion of a hitch 2.

In the figures, a ball coupling 2 is shown but the present invention is not necessarily limited to such a coupling. Thus, the present invention relates to any type of hitch 2 comprising an end portion of attachment and its complementary part which fixes the end portion of attachment to the vehicle. The term "ball" must here be understood in the broad sense, especially as an element that may not be totally spherical, for example comprising a flat or presenting an ovoid surface. In the figures, the hitch 2 comprises a ball 3 and a neck 4 forming the terminal attachment part of the hitch 2 and an angled arm 2a forming the remainder of the hitch 2 other than the terminal attachment portion 3, 4.

 The bent arm 2a of the hitch 2, directly adjacent to said ball 3 via the neck 4, connects them to the chassis of the vehicle, not shown in the figures. The terminal end portion 3, 4 of the hitch 2 extends substantially vertically when the hitch 2 is in a fixed position on the vehicle. The neck 4, of substantially cylindrical shape, particularly clearly visible in Figures 2 to 4 and 6 to 10, connects the ball 3 to the bent arm 2a. According to one possibility, the neck 4 comprises a shoulder 5 extending at least partially around the periphery of the neck 4 and being at the end of the neck 4 opposite that connected to the ball 3, this shoulder 5 protruding transversely to the neck 4.

 As previously mentioned, the connection system 1 connects to the ball hitch 2 a carrying device, the latter being symbolized by a platform 19 shown interrupted in Figures 2 to 4. The platform 19 can be directly reported to the connection system 1 as shown in Figures 2 to 4 or indirectly via an arm 25 for example, as shown in Figures 5 to 12. In the latter case, the arm 25 comprises a threaded hole 27 facilitating the attachment of the platform 19. The term platform 19 is broadly defined as a counterweight or a remote load. It can also take the form of a vertical beam with arm supporting for example bicycles. This platform 19 shown interrupted in Figures 2 to 4 represents the master platform of the carrying device, the latter extending advantageously in the longitudinal direction of the vehicle at the rear of said vehicle. The platform 19 is preferably substantially horizontal when the system 1 is attached to the coupling 2. The platform 19 is preferably arranged in a plane inclined with respect to the longitudinal axis 20 of the cavity 10. The plane of the platform 19 and the longitudinal axis 20 preferably forms an acute angle, for example of the order of 30 ° to 70 ° preferably 45 °. In this way, the platform 19 is disposed along the longitudinal axis of the vehicle, once the system is in the carrying position on the hitch.

Preferably, the angle formed between the plane of the platform 19 and the longitudinal axis of the vehicle is substantially identical to the necessary deflection for the tilting of the connection system 1 ,, or, according to one possibility, the angle formed between the first part 1 1 and the second part 1 1 a of the groove.

 For example, in the case of a carrier device for bicycles, with a carrying device having such a master platform, one or more bicycles are arranged transversely to the vehicle being individually fixed by respective fastening means on the master platform. . However, it is possible to design a master platform extending transversely to the rear of the vehicle and the bicycle or bicycles then extending longitudinally to the vehicle. In this case, the platform 1 9 shown interrupted in Figures 2 to 4 is a platform for connecting the master platform of the carrying device to the connection system 1, the connection platform extending substantially perpendicular to the master platform.

 The connection system 1 forms a substantially closed assembly with, in its interior, between two longitudinal faces of flat outer shape, a housing 6 for receiving the ball 3 of the coupling 2, this housing 6 being visible in FIGS. 2 to 4 and 6 to 12. The housing 6 for the reception of the ball 3 is in a cavity 10 extending in the connection system 1, the fictitious center of the ball 3 in position in this housing 6 being referenced 21 in FIG. 2. According to the invention, the connection system comprises a one-piece body in which the cavity 10 is formed. According to one possibility, illustrated in particular in FIGS. 1 to 4, in the housing 6, bearing surfaces 7 and 8 are provided. performing a different and complementary action on the ball 3 and its neck 4, the bearing surfaces 7 to 8 will be described later.

 The cavity 10 has at least one emergent end 23. The terminal attachment part 3, 4 is introduced into the cavity 10 by the end 23. In FIGS. 2 to 4, the open end 23 is oriented in a non-parallel plane and preferably perpendicular to the longitudinal axis 20 of the cavity 10.

According to a possibility not shown, the cavity 10 may comprise two open ends. In this way, the end part of attachment 3, 4 is secured by a movable part for gripping the terminal end portion 3, 4 in the cavity 10.

 The system 1 comprises an insertion portion 12 and a fixing portion 32. The insertion portion 12 corresponds to the portion of the cavity 10 in which the terminal attachment portion 3, 4 is introduced into the system 1. The attachment portion 32 corresponds to the portion of the cavity 10 in which the terminal attachment portion 3, 4 is positioned when the system 1 is fixed on the hitch 2.

 The insertion portion 12 and the attachment portion 32 may or may not have common cavity surfaces. In particular in the embodiment illustrated in FIGS. 5 to 12, the housing 6 is common to the insertion portion 12 and to the fixing portion 32.

 According to a possibility that is particularly illustrated in FIGS. 1 to 4, the cavity 10 may have a sheath shape with a substantially cylindrical insertion portion 12 with a longitudinal axis referenced 20 and an attachment portion formed by the housing 6 of substantially spherical shape for its complementary part to the ball 3.

 The sheath shape is understood as an elongate sheath in the direction of insertion of the end portion into the cavity 10.

 According to a possibility illustrated in particular in FIGS. 1 to 4, the device also has, in the lower part of the cavity 10 cooperating with the neck 4, a groove formed by a first portion 1 1 and a second part 1 1 a consecutive for the passage of the neck 4 and / or the rest of the bent arm 2a of the hitch 2 out of the cavity 10, said groove portions 1 1 and 1 1 a being visible in Figures 2 to 4. The rest of the crank arm 2a other that the terminal end portion 3, 4 is separated from the neck 4 and the ball 3 for example by a shoulder 5 itself disposed outside the connection system 1 advantageously abuts against the lower part of the connection system 1.

The first part of the groove 1 1 is associated with the insertion portion 12 and the second portion of the groove 11a is associated with the fastening portion formed by the housing 6 at least partially providing the fastening aperture 34 The groove advantageously extends over the entire length of the cavity 10. The two parts 1 1 and 1 1 a of the groove are preferably arranged in a groove. same vertical plane and advantageously have a rectilinear section. Preferably, the first part 1 1 and the second part 1 1 a have a non-zero angle between them advantageously so that in fixing position at least the first support means 7 are formed by the edges of said first groove portion 1 1 against the ball 3.

 Fixing position means that the ball 3 is positioned at the fixing portion.

 The insertion of the end portion 3, 4 in the cavity 10 is done by the emergent end 23 preferably located at the end of the insertion portion 12. The introduction can be done in a translational movement along a plane substantially horizontal, and / or preferably along an axis perpendicular to the longitudinal axis 22 of the end portion 3, 4 as illustrated in Figures 2 to 4 or by a translational movement along an axis parallel to the longitudinal axis 22 of the terminal part 3,4 ..

 The cavity 10 and the groove are configured to generate a sliding fit of the end portion and more precisely of the ball 3 and the neck 4 relative to the insertion portion 12. For this purpose, the cavity 10 has an arcuate section of complementary circle of the ball 3, while the groove is adapted to allow the sliding of the neck 4. For example, the cavity 10 and the groove for sliding have dimensions greater than the dimensions of the terminal portion of attachment 3 , 4 preferably of the order of one tenth of a centimeter.

 For example, the ball 3 has for a larger dimension a diameter of 48 to 50 millimeters and the neck 4 of 27 to 29 millimeters.

 The groove also has a width smaller than the greatest width, ie the diameter of the ball 3. In this way, the ball 3 is maintained in the cavity 10. The displacements along the longitudinal axis of the end portion are reduced or prohibited.

Thus, in the attachment position of the connection system 1, there is a first bearing surface 7 disposed on the side of the ball 3 of the coupling 2 facing the open end 23 of the insertion portion 12 of the cavity 10. The bearing surface 7 is located at the first part 1 1 of the groove preferentially formed by the insertion portion on either side of the groove.

 In the fixing position of the connection system 1, a bottom portion 13 of the cavity 10 is in the housing 6 abutting against the ball 3 and the neck 4, a bearing portion 13a of this bottom portion 13 having a shape corresponding to the ball 3 and / or the neck 4. Thus, there is therefore at least a second bearing surface 8 of the connection system 1 with the ball 3 and / or the neck 4 of the hitch 2. Advantageously this second bearing surface 8 is at least effective between the neck 4 of the coupling 2 and the bearing portion 13a facing said collar 4. This bearing portion 13a of the bottom portion 13 advantageously has a profile complementary to the neck 4. As the neck 4 is substantially cylindrical in shape, the bearing portion 13a of the bottom portion 13 may be substantially circular in shape so that the contact between the bearing portion 13a and the portion vis-à-vis the neck 4 is optimal.

 Preferably, the bottom portion 13 comprises a metal reinforcement forming the bearing portion 13a. The metal reinforcement makes it possible to increase the hardness of the bottom portion 13 and thus improves the support of the portion 13a thus avoiding wear by matting.

 These two bearing surfaces 7 and 8 generate a self-tightening of the end portion 3, 4 in the carrying system.

The self-tightening is particularly effective when the system comprises a platform 19 extending from said connection system. This platform 19 is preferably substantially horizontal, that is to say parallel to the longitudinal axis of the vehicle. The platform 19 exerts a weight applied at a certain distance from the center of gravity of the ball 3 of the terminal attachment part. The vertical axis rotation along the longitudinal axis of the end portion 3, 4 is locked only by friction if the tangential force does not exceed the rotational torque due to the lateral acceleration. Only if this weight exceeds a certain value, the self-tightening achieved by the first 7 and the second 8 bearing surfaces is satisfactory. By way of example, this weight must be greater than 60 kg and be exercised at about 70 centimeters from the center of gravity of the ball 3 so that the moment of force has this effect on an 3 standard ball. Otherwise, it is preferred to provide a third bearing surface 9 which will be described below.

 According to this possibility illustrated in FIGS. 1 to 4, the present invention also relates to a method of blocking a connection system 1 on the end portion 3, 4 of a hitch 2.

 This process comprises the following steps:

 - insertion of the end portion 3, 4 in the cavity 1 0 by the outlet end 23. The cavity 10 is oriented so that the longitudinal axis 20 is substantially perpendicular to the longitudinal axis 22 of the end portion 3, 4 .

 pouring of the cavity 1 0 of the system 1 around said end portion 3, 4, until said end portion 3, 4 is in the fixing portion preferably at the innermost end of the portion d insertion of the cavity 10. The sliding is preferably rectilinear.

 - Tilt of the connection system 1 causing a passage of the end portion of attachment 3, 4 in the fixing portion of the cavity 10. This tilting causing an automatic locking of the cavity 10 relative to the end portion of attachment 3 4 by pressing, on the side turned towards the end opening 23, at least one edge of the first part 1 1 of the groove against the terminal end portion 3, 4 and, on the other opposite side at the open end, at least one bearing portion 13a of the bottom piece 13 of the cavity 10 against said end portion 3, 4.

 Advantageously, the tilting takes place between a position where the longitudinal axis 20 of the cavity 10 extends substantially horizontally and a position in which the longitudinal axis 20 is inclined by approximately 45 ° relative to the horizontal. More specifically, the tilting is carried out between a position where the longitudinal axis 20 of the cavity and the longitudinal axis 22 of the end portion 3, 4 are substantially perpendicular and a position in which the longitudinal axis 20 is inclined of the order of 45 ° with the longitudinal axis 22.

Advantageously, the method has a step of locking in rotation of the connection system 1 about the longitudinal axis 22 of the terminal end portion 3, 4 made by applying a bearing surface on the free end 3a of said end portion 3, 4. In a preferred embodiment, the first bearing surface 7 advantageously allows a connection of the unilateral ball-and-socket type with the median hemispherical portion of the hitch ball 3, this portion being oriented towards the emergent end 23 forming the opening of the cavity 10. The first bearing surface 7 is conjugated with the second bearing surface 8, advantageously present between the cylindrical portion of the neck 4 disposed under the ball 3 and the portion of support 1 3a of the portion bottom 1 3, the said cylindrical portion of the neck 4 being vis-à-vis the bottom portion 13 of the cavity 10.

 The effect of the first 7 and second bearing surface 8 is to create, on the one hand by the first bearing surface 7, a pivot-unilateral connection generating bearings on a portion of the ball 3 turned towards the end of the cavity 21 of the cavity 10. On the other hand, it is created by the second bearing surface 8 on a portion of the terminal attachment portion 3, 4 facing the bottom of the cavity 10 a connection advantageously of the type support-plane which locks said pivot-unilateral connection. As previously mentioned, the connection of the second bearing surface 8 is advantageously performed on the neck 4 extending the ball 3 to the bent arm 2a.

 Advantageously, for the connection system 1 according to the present invention, there is provided a third bearing surface 9 between the ball 3 of the coupling 2 and the connection system 1. The third bearing surface 9 contributes to a self-tightening of the connection system 1 on the hitch 2 and to prevent rotation about a vertical axis of the connection system 1 relative to the ball 3, this vertical axis being the longitudinal axis 22 of the terminal end portion 3, 4.

 The third bearing surface 9 makes it possible to extend the bearing surfaces, in particular 7 and 8, in order to reduce the surface pressures in the cavity 10 and reduce the risk of matting thereof.

 It is particularly useful in the following cases, which can be encountered in combination:

- The diameter of the ball 3 is low, the third bearing surface 9 then compensates the game; - The weight of the coupling is low so that the moment of force it exerts to achieve the automatic tightening torque for the surfaces 7, 8 is lower; the third bearing surface 9 then completes the self-tightening.

 Preferably, the third bearing surface 9 is made by the tip 15 of a moving part 14 acting on the upper part of the ball 3, this portion advantageously having a flat portion 3a and forming the free end portion of the end portion attachment 3, 4 of the coupling. The moving part 14 is articulated around an axis 16 of articulation, this axis 16 extending substantially horizontally in the mounted position of the connection system 1 transversely to said system 1. Advantageously, under the actuation of a clamping lever 17 associated with the moving part 14, by the action of an operator on the gripping portion 18 of said lever 17, this preferably by lowering said lever 17, the moving part 14 is pivoted around the axis 16 and its tip 15 comes into contact with the flat part 3a of the ball 3. This prevents any vertical rotation of the connection system 1 relative to the coupling 2 for a sufficient pressure of the tip 15 of the workpiece mobile 14 on the flat 3a at the top of the ball 3.

 In a complementary manner, a locking of the connection system 1 in position on the hitch 2 is achieved in particular by the clamping lever 17. The locking makes it possible to compensate for load shedding during vertical accelerations.

 This results in easy positioning of the connection system 1 according to the present invention around the terminal attachment part 3, 4 of the coupling 2, this with a self-tightening by the combined action of at least two surfaces of support 7, 8, the third bearing surface 9 being optional but completing the tightening of the connection system 1 on the end portion 3, 4 of the coupling 2.

According to another aspect of the invention referring to FIGS. 5 to 12, the connection system 1 also comprises, inside, a housing 6 for receiving the ball 3 of the hitch 2. The housing 6 is in the cavity 10. The housing 6 is configured to receive the ball 3. The housing is preferably substantially of a shape complementary to the ball 3. The cavity 10 also comprises a through end 23. The end attachment part 3, 4 is introduced into the cavity 10 through the open end 23.

 The connection system 1 comprises an insertion portion 12 and the fixing portion 32. The insertion portion 12 comprises the open end 23.

 In this embodiment, the groove described for the embodiment shown in Figures 1 to 4 is reduced to its simplest expression in length. Principally, the groove is at the attachment portion 32. At least a portion of the groove forms at least a portion of the fastening aperture 34.

 The terminal end portion 3, 4 is introduced into the cavity 10 through the outlet end 23 as illustrated in FIG. 7. By a rotation of the system 1 and in particular of the cavity 10 around the ball 3, the end portion of fastener 3, 4 passes from the insertion portion 12 to the fastening portion 32.

 During this rotation, the cavity 10 rotates around the ball 3 and the neck 4 slides between the open end 23 and a fastening aperture 34. The rotation is preferably a pivoting of the system 1 around the coupling 2. The rotation thus comprises a sliding and tilting of the system 1 around the hitch 2.

 The sliding is a translation along the mouth of the open end 23 and that of the fastening opening 34. The fastening aperture 34 extends the open end 23. The fastening aperture 34 is arranged at the fixing portion 32. It corresponds substantially to the groove, specifically to the second portion 1 1a of the groove.

 Advantageously, the mouth of the open end 23 and the mouth of the fastening aperture 34 form a non-zero angle between them. Preferably, the angle is between 25 and 50 °, preferably between 30 and 45 °. This angle corresponds to the angular displacement of the system 1 during the rotation of the cavity 10 around the terminal end portion 3, 4.

According to one embodiment, the system 1 comprises a rounded surface 36 between the mouth of the outlet end 23 and the mouth of the fastening aperture 34 forming a fillet. This rounded surface 36 facilitates the pivoting of the system 1 relative to the coupling 2.

 The emergent end 23 has dimensions greater than those of the ball 3, preferably the emergent end 23 has a section greater than that of the ball 3 to allow its insertion into the cavity 10.

 The fastening aperture 34 preferably has dimensions smaller than those of the ball 3, preferably the fastening opening 34 has a section smaller than that of the ball 3 and greater than that of the neck 4 so as to keep the ball 3 in position. the housing 6. The fastening opening 34 has smaller dimensions than the open end 23.

 According to this variant of the invention, the system 1 comprises a stop surface 29 formed in the cavity 10. The stop surface 29 is in one piece with the cavity 10. The stop surface 29 is arranged to take alternately a position inactive and an active position. The change of state from the inactive position to the active position, and vice versa, is effected by a rotation of the system 1 around the terminal end portion 3, 4. In the inactive position, the stop surface 29 is moved away from the end portion of attachment 3, 4 while in the active position, the stop surface 29 is in application against the end portion of attachment 3, 4. Preferably, the stop surface 29 is in application against at least a portion of the neck 4. The stop surface 29 is advantageously formed by a surface of the fixing opening 34. The stop surface 29 is configured to block at least one degree of freedom of the system 1 relative to the hitch 2. More precisely, the stop surface 29 can block the mobility of the system 1 at least according to two degrees of freedom of rotation and two degrees of freedom in translation.

 The stop surface 29 is preferably configured to allow a surface application on an angular sector of the neck 4 between 5 and 40 °, more precisely between 5 and 30 °, preferably 20 to 25 °.

The stop surface 29 has a profile partially complementary to the neck 4. The neck 4 being commonly cylindrical, the stop surface 29 is substantially circular, so that the contact between the neck 4 and the stop surface 29 is optimal. . Preferably, when the terminal end portion 3, 4 is in the fixing position, the ball 3 is in contact with a surface of the bottom portion 13 of the system 1. The bottom portion 13 is in the housing 6 and is able to abut against the ball 3. According to one possibility, the bottom portion 13 represents an angular sector of 100 to 200 ° enveloping the ball 3.

 According to an advantageous possibility, the system 1 comprises a clamping means intended to adapt the system 1 to different types of couplers 2, of different shapes and dimensions. This means comprises a lumen 31 formed in the system 1 opening into the cavity 10, more precisely in the housing 6, preferably at the level of the bottom portion 13.

 This light 31 is configured to receive a movable element intended to come into contact with the ball 3. This movable element is for example a screw socket 24. Preferably, the screw socket 24 is hollow so that it generates a circular surface contact on the ball 3, more precisely annular. This circular surface is called locking surface 30. It makes it possible to ensure that the terminal attachment part 3, 4 is in the fixing position and that it is in contact at least with the stop surface 29 and preferably also with the bottom portion 13. Its adjustment, in particular by screwing, makes it possible to accommodate variations in the size of the ball 3. In order to allow satisfactory annular contact, it is preferred that the axis of symmetry of the annular surface is arranged so as to correspond to a diameter of the ball 3. According to one possibility, when the housing corresponds to a sphere, this axis of symmetry of the annular surface corresponds to a diameter 37 of the housing 6.

 The lumen 31 is preferentially formed opposite the bottom portion 13. Preferably, the lumen 31 is formed in the insertion portion 12.

 The system 1, according to this variant illustrated in Figures 5 to 12, advantageously comprises a locking surface 28. This locking surface 28 is intended to block the last degrees of freedom of the system 1 vis-à-vis the coupling 2 .

The locking surface 28 is preferably mobile. It is, for example, advantageously formed at the free end of a lever arm 25. The system preferably comprises an opening through which is arranged the lever arm 25 movable about a hinge axis 26 also allowing its attachment to the system 1. The opening opens into the housing 6. The end of the lever arm 25 is thus movable so that the locking surface 28 alternately takes an active position in application against the terminal end portion 3, 4 and a retracted position in which the locking surface 28 is remote from the terminal end portion 3, 4.

 Advantageously, the lever arm 25 is connected to the platform 19 more generally to the carrying device. The weight exerted by the carrying device on the lever arm 25 exerts an application force on the locking surface 28 allowing locking of the end portion 3, 4 in the system 1.

 The locking surface 28 is preferably a flat surface substantially corresponding to the section of the opening through which it comes into contact with the terminal end portion 3, 4. Preferably, this locking surface 28 is applied against the ball 3 .

 To improve the clamping, the end of the lever arm 25, including the locking surface 28, is an asymmetric beveled tip so that the locking surface 28 represents the largest area of the end.

 To ensure the safety of the system 1, there can be provided a locking means of the lever arm 25 in the locking position. For example, a pin can be provided.

 It is particularly advantageous that the locking surface 28 and the blocking surface 30 are arranged diametrically opposite. The force exerted by the locking surface 28 on the terminal end portion 3, 4 is taken up mainly by the locking surface 30.

The invention is not limited to the embodiment described but extends to any embodiment within its spirit. REFERENCES

1. Connection system 19. Platform

 2. Coupling 20. Longitudinal axis of the cavity

2a. Angled arm 21. Center of the ball

 3. Ball 22. Longitudinal axis of the part

3a. Terminal 30 terminal plate

 4. Pass 23. Ending end

 10 5. Shoulder 24. Screw Socket

 6. Receiving housing 25. Leverage arm (connection to the

7. First platform support surface

 8. Second bearing surface 35 26. Articulation axis

 9. Third support surface 27. Threaded hole

 10. Cavity 28. Locking surface

 1 1. First groove portion 29. Stop surface

 11 a. Second groove portion 30. Blocking surface

 12. Insertion portion 40 31. Light

 13. Bottom portion 32. Fixing portion

 13a. Supporting portion 33. Angular deviation of the

14. Rotating mobile part

 15. Tip 34. Fastening opening

 16. Joint shaft 45 35. Groove

 17. Clamp lever 36. Rounded surface

 18. Gripping portion 37. Housing diameter

Claims

1. Connection system (1) for attaching a carrying device to a hitch (2) having a terminal attachment portion comprising a ball (3) and a neck (4), the system (1) comprising a cavity ( 10) internal open at least one open end (23) and adapted to receive the ball (3) of the terminal portion characterized in that the cavity (10) comprises an insertion portion (12), at the free end of which is arranged the outlet end (23), and a fixing portion each adapted to receive the ball (3). ), and in that the fixing portion (32) comprises a stop surface (29) configured to alternately rotate said cavity (10) by an inactive position in which the stop surface (29) is adapted to away from the terminal end portion (3, 4) and an operative position in which the stop surface (29) is adapted to be applied against the terminal end portion (3, 4). 2. System according to the preceding claim wherein the stop surface (29) is adapted to be applied in the active position against at least a portion of the neck (4). 3. System according to any one of the preceding claims wherein the fixing portion (32) comprises a fastening opening (34) extending the open end (23) of the insertion portion (12) and forms a non zero with the mouth of the open end (23). 4. System according to the preceding claim wherein the fastening opening (34) is of smaller dimensions than those of the open end (23) so as to maintain the ball (3) in the cavity (10). 5. System according to any one of the preceding claims comprising a locking surface (28) movable relative to the cavity (10) between an application position against the end portion of attachment (3, 4) and a retracted position. 6. System according to the preceding claim wherein the locking surface (28) is formed on a lever arm (25) adapted to allow the application of the locking surface (28) against the ball (3) of the end portion. attachment (3, 4). 7. System according to any one of the preceding claims comprising a blocking surface (30) arranged at least in the insertion portion (12). 8. System according to the preceding claim in combination with any one of claims 5 or 6 wherein the locking surface (30) is arranged at least partially diametrically opposite the locking surface (28). 9. System according to the preceding claim wherein the locking surface (30) has an annular shape and whose axis of symmetry is adapted to be aligned with a diameter of the ball (3) adapted to be positioned in the fixing portion. (32). 10. System according to any one of the preceding claims in combination with claim 3 wherein the system comprises a groove, at least a portion of which forms the fastening opening (32), adapted to allow the passage of the neck (4). and having at least a first portion (1 1) extending at the insertion portion (12) and a second portion (1 1 a) extending at the attachment portion (32). 1 1. System (1) according to the preceding claim wherein the groove has a width smaller than the largest dimension of the ball (3). 12. System (1) according to any one of the three preceding claims, wherein the cavity (10) has a sheath shape. 13. System (1) according to any one of the four preceding claims wherein the first portion (1 1) of the groove is oriented in a plane not parallel to that of the open end (23). 14. System (1) according to any one of the five preceding claims wherein the groove has a rectilinear section. 15. System (1) according to any one of the six preceding claims wherein the first portion (1 1) and the second portion (1 1 a) of the groove form a non-zero angle between them. System according to any one of the preceding claims wherein the groove is configured to guide the end portion (3, 4) of the hitch (2) in a direction perpendicular to the longitudinal axis (22) of the portion. terminal (3, 4). 17. System according to any one of the eight preceding claims wherein at least a first bearing surface (7) adapted to be in contact with the end portion of the hitch (2) is formed by the cavity (10) at level of its insertion portion (12) on either side of the groove. 18. System according to the preceding claim wherein at least a second bearing surface (8) adapted to be in contact with the end portion is formed by the cavity (10) in the fixing portion (12) at a bottom portion (13) so that the first bearing surface (7) and the second bearing surface (8) automatically block the cavity (10) from the end portion (3, 4). 19. System (1) according to the preceding claim wherein the bottom portion (13) comprises a metal reinforcement adapted to be in contact with a portion of the neck (4). 20. System (1) according to any one of the preceding claims comprising a platform (19) extending from one of these ends and whose longitudinal plane forms an acute angle preferably 30 to 70 °, with longitudinal axis (20) of the cavity (10). 21. System (1) according to any one of the preceding claims wherein a third bearing surface (9) is formed by the cavity (10) in the attachment portion at an area opposite the groove. 22. System (1) according to the preceding claim wherein the third bearing surface (9) is movable between an application position on the end portion (3, 4) and a retracted position. 23. Device for carrying one or more elements at the rear of a vehicle, characterized in that it comprises a system (1) connection according to any one of the preceding claims. 24. A carrying device according to the preceding claim, characterized in that it is able to carry one or bikes. 25. An assembly comprising a hitch (2) ball (3) with a system (1) connection according to any one of claims 1 to 22 or with a carrying device according to any one of the two preceding claims, the part attachment end (3, 4) of the coupling (2) being substantially vertical and comprising a ball (3) connected by a neck (4) in addition to the end portion (3, 4) in the form of an arm bent (2a). 26. Assembly according to the preceding claim wherein the groove has a vertical plane of symmetry. 27. An assembly according to any one of the two preceding claims wherein the first portion (1 1) and the second portion (1 1 a) of the groove form a non-zero angle between them in a vertical plane. 28. An assembly according to any one of the three preceding claims wherein the cavity (10) and the groove are configured to create a sliding fit with the end portion (3, 4) of the hitch (2). 29. An assembly according to any one of the four preceding claims, in which the first bearing surface (7) of the system (1) is applied at least against a portion of the ball (3) facing towards the open end ( 23) of the cavity (10) and the second bearing surface (8) of the system (1) is applied against at least a portion of the neck (4) vis-à-vis a bottom portion (13). ). 30. An assembly according to any one of the five preceding claims, for which the ball (3) of the coupling (2) comprises, at its apex forming the free end of the terminal end portion (3, 4), a flat part (3a). 31. Method for blocking a connection system (1) according to any one of Claims 1 to 22, characterized in that it comprises the following steps:  inserting said end portion (3, 4) in the insertion portion (12) of the cavity (10)  - rotation of the connection system (1) causing placement of the terminal end portion (3, 4) in the attachment portion (6) of the cavity (10) and automatic locking of the cavity (10) relative to at the terminal end portion (3, 4). 32. A method according to the preceding claim wherein the rotation is performed by the weight exerted away from the center of gravity of the ball (3) by a platform (19) extending from one of these ends from the system of connection. 33. Method according to any one of the two preceding claims wherein the rotation is performed on an angular sector (33) between 25 and 50 °, preferably 25 to 30 °. 34. A method according to any one of the three preceding claims, which has a locking step of the connection system performed by applying a locking surface (28) to the ball (3) of the terminal end portion (3, 4). 35. Method according to the preceding claim, wherein the tilting takes place between a position where the longitudinal axis (20) of the cavity (10) extends substantially horizontally and a position in which the longitudinal axis (20) is tilted about 45 ° to the horizontal. 36. A method according to any one of the two preceding claims, which has a locking step in rotation of the system (1) for connection about the longitudinal axis (22) of the terminal portion of attachment (3, 4) carried out by applying a bearing surface on the free end of said end portion (3, 4).