WO2008049569A1

WO2008049569A1 - Trailer device

Info

Publication number: WO2008049569A1
Application number: PCT/EP2007/009166
Authority: WO
Inventors: Mathias HÜSING; Guido Lonij; Burkhard Corves
Original assignee: Rheinisch-Westfälische Technische Hochschule Aachen
Priority date: 2006-10-25
Filing date: 2007-10-23
Publication date: 2008-05-02
Also published as: DE102006051096A1; DE102006051096B4

Abstract

The invention relates to a trailer device for motor vehicles, which is arranged in a manner mounted on the vehicle via a frame component and has a ball-headed bar (6) which can be pivoted from an operative position into an inoperative position and vice versa, in which the ball-headed bar (6) can be pivoted about a central point (37) and about an axis which is not spatially fixed and runs through the central point (37).

Description

hitch

The invention relates to a towing device for motor vehicles, which is arranged fixed to the vehicle via a frame member and having a ball bar which is pivotable from a use in a rest position and vice versa.

This is in particular a device for lowering and pivoting a trailer hitch for motor vehicles, in which a provided with a standard coupling ball ball rod from a non-visible from outside the vehicle rest position in a suitable for attaching a trailer operating position is driven by a motor or manually movable. Said ball bar can be synonymous as a coupling arm.

A trailer hitch or hitch is a necessary device with which a motor vehicle must be equipped to tow a trailer. Core component of the hitch is provided with a standard coupling ball ball rod. On the trailer is a counterpart to a ball socket. Are ball and ball socket coupled together, the ball socket is rotatably mounted on the ball. This allows the trailer to follow the towing vehicle articulated. The trailer hitch also serves as a basis for other transport devices, such. B. bike rack.

Hitches currently available on the market are divided into the following categories.

The first category of rigid hitches is characterized in that the ball bar with a standardized ball is positively or materially connected to a frame which is mounted on the body of the motor vehicle. The Connections are not suitable or only conditionally for quick disassembly of the hitch.

In addition, there is a second category of towbars with detachable ball bar for motor vehicles. Aspects of a functional or aesthetic nature require the detachability of the ball bar. For example, registration plates may not be obscured by the attachment device. Deep on the vehicle rear arranged license plate can remain uncovered by removing the ball rod. The restoration of the impaired beauty of shape of the vehicle rear due to the outstanding ball bar can also be achieved by its decrease. The disassembly of the ball rod and storage of the ball rod in the non-use state of the hitch and the safekeeping of the assembly tool must also be taken into account.

The third category of hitches is characterized by a movable ball bar. This category hitching allows the movement of the ball bar between a rearward facing relative to the motor vehicle for securing a trailer suitable position for use and a non-visible from outside the vehicle rest position and does not require disassembly of individual components. The ball bar is moved either manually or by motor between position of use and rest position and locked for safety reasons in both end positions. The locking is positive or non-positive nature of the positive locking is the preferred because safer variant.

There are various embodiments of such manually or motor-driven trailer hitches known, for example, DE 198 26 618, DE 199 44 0264 and DE 100 04 523, in which a perpendicular ball bar is first moved axially so down that the ball of the ball bar below the bumper lies. Thereafter, the ball bar is rotated about 90 ° about the vertical axis and then raised again until the ball rod is in the operating position. With this embodiment disadvantages are associated with respect to the available space. For example, the ground clearance is not sufficient depending on the vehicle type and requires the vertically arranged ball bar a high space, which can not be agreed with the desire of a low-lying luggage compartment edge of modern motor vehicles.

In terms of cost-effectiveness, the high costs and the complex construction for two motor drives and a complicated control of the drives are to be considered as disadvantages of this variant. In addition, the high operating forces require accurate guidance over relatively long distances and the use of high quality materials while ensuring adequate safety. A waiver of motor drives requires multiple grasping during the procedure of the ball rod and thus compromises the comfort and ease of use.

A further embodiment variant comprises a ball bar, which is arranged on a vehicle-fixed pivot bearing and is pivoted by motor from a rest position located below the vehicle floor into the operating position (for example DE 196 54 867, DE 196 12 959 or WO 98/57 813). This embodiment shows disadvantages in terms of the available space. The ground clearance is not sufficient depending on the vehicle type and arranged in the rest position under the vehicle floor ball bar can not be agreed with a low-lying trunk floor.

From DE 100 23 640 and DE 101 04 185 a variant is further known in which the ball bar is pivotally connected to a bearing block. Wherein the bearing block itself can pivot about an axis arranged in the vehicle direction, whereby a lowering and then pivoting movement is generated. Disadvantages of this embodiment variant are the use of two Motorized drives that realize the steps of lowering, turning and lifting with the help of a complicated control.

A very cost-effective embodiment variant is described in EP 1 586471, EP 1 586470 and EP 1 584499. Here, a ball rod is firmly connected to a Drehachsglied. The rotary axis link is linearly displaced in the housing. The rotation of the ball bar in the direction of the vehicle longitudinal axis takes place in a form-fitting manner, e.g. by an eccentrically mounted bolt, which conveys conditionally by a backdrop the ball rod in the operating condition. Disadvantages of this solution variant are the lack of possibility of a sufficient lowering of the ball rod in motor vehicles with low ground clearance and the achievement of a sufficient height of the coupling ball.

From DE 101 04 185 a motor-driven pivotable trailer hitch is known in which the ball rod is also rotated about its vertical axis and during pivoting performs a high-low movement, which is generated by means of curve or gate elements.

Finally, an embodiment EP 1 533 149 is known in which a ball rod is pivotally mounted in a swash bearing. In addition, this bearing offers the possibility of an axial displacement, with the locking of the mechanism can be canceled. In addition, the ball bar is guided by means of a backdrop contained in this part and engaging in follower means. A disadvantage of this embodiment is the very complex construction of the swash bearing.

There are known from EP1634730 and WO205 / 110781 embodiments in which the ball bar is attached to a support ball. The support ball is in turn performed at least in a storage tray. The ball joint thus produced would have undesirable 3 degrees of freedom (pivoting about three space-fixed axes). In this respect, elements (balls or bolts) are mounted between the bearing ball and the bearing shell, which engage in associated scenes and thus guide the ball bar so that the desired or required rotational-pivoting movement is generated. Here, a spherical cam gear was realized. For the appropriate fulfillment of the desired motion task of the ball rod, it is necessary that the contact surfaces, especially between bearing ball and the associated storage shells but also engaging in the scenes elements are always well lubricated. Below the vehicle there is an increased risk of contamination. So that no dirt enters the joints and the lubricant is not washed out in the joints, a complex seal against environmental influences and dirt is required. The required lubrication properties must be checked during maintenance. In this respect, the embodiments described here are very maintenance-intensive. A setting of the bearing ball with the bearings for locking appears not suitable because of the required lubrication.

Most of the mentioned embodiments use sliders for sliding or sliding elements, which must always be sufficiently lubricated. They must therefore always be excellent sealed and maintained. The proper sealing increases the manufacturing costs, the required maintenance increases the operating costs.

task

The invention has for its object to provide a hitch with movable ball bar, which requires the smallest possible space, which preferably requires a single drive for the adjustment of the ball rod between two end positions and the operation of the locking device, which contains as few components as possible is inexpensive to manufacture, which does not require expensive sealing elements and the pivot elements require no maintenance and thus minimal

Operating costs incurred. In the hitch of the type described above, this object is achieved, that the ball rod is pivotable about a central point and about an axis extending through the central point not solid axis.

In a preferred development, a first and a second connecting member may be rotatably mounted on the frame component and the ball rod may be rotatably connected to the first and the second connecting member via a third connecting member, with the axes of rotation of all the connecting members intersecting in a central point.

Thus, the pivot elements may comprise only three moving members and a frame-fixed frame member here. The frame member is firmly connected to the body of the motor vehicle. In him two of the three moving members are rotatably mounted as wings, in turn, the ball rod is rotatably mounted respectively. The special feature is that the links are shaped in such a way that all axes of rotation intersect at a central point and thus the thus realized pivot mechanism can be forcibly moved (spherical arrangement). By using simple swivel joints can be dispensed with wear-consuming and maintenance-consuming link elements. The use of simple hinges makes the swivel easy, inexpensive and maintenance-free

Due to the spherical arrangement of the mechanism is very easy scalable and adaptable to the respective space conditions.

The ball bar is therefore guided with the coupling of a four-membered spherical mechanism. As with a cardan joint, all points of the individual limbs move on concentric spherical surfaces. The difference to the universal joint is that the angles between the joint axes in universal joints are 90 °. The angles between the joint axes of the Hitch not necessarily 90 ° and preferably deviate from 90 degrees.

By different angles between the joint axes, the movement of the ball rod can be adapted to the respective space restrictions of the motor vehicle. The use of simple hinges in combination with the Achslage and -orientation allows a cost-effective production of the device which is nevertheless able to realize a very complex movement of the ball rod.

Preferably, only one of the connecting members is driven by a motor or manually. Particularly advantageous is the drive of one of the two coupled to the frame member connecting members due to the fixed hinge axis. The movement of the ball bar and the movement of the other two links are dependent on the movement of the driven link. The use of a single drive allows a cost savings and a simplification of the device with respect to pivotable towbars with two drives.

Furthermore, the drive of the connecting member can additionally be used for the actuation of the locking device. In the case of a blockage of the driven member, a Maltese cross gear can be used. The Maltese cross gear is characterized in that the drive shaft, which is driven either by motor or manually, has a certain center distance to the axis of rotation of the driven link.

It can be provided that a bolt arranged on the drive shaft is introduced during the rotational movement of the drive shaft into a groove of the driven connecting member such that the driving motor shaft movement generates a pivoting of the driven connecting member. When the bolt exits the groove locking elements of the drive shaft and the driven link so inserted into each other, that further pivoting of the driven link is prevented.

The drive of the connecting member can additionally be used for the actuation of the locking device. An additional cost, in the form of a second drive for locking, or an additional operating effort, with manual pivoting of the hitch from the rest position to the use position which requires a complicated sequence of manipulations of the operator is thus prevented. In addition, further stress on the installation space in the form of an additional drive unit is avoided.

Particularly advantageous in terms of the claimed installation space is a hitch which is characterized in that either one of the two connecting members or the ball bar can be manually pivoted, wherein the operation of the locking device can also be done manually. Due to the spherical arrangement a continuous movement of the manually moving member is enabled after unlocking, which benefits the handling of the device by an operator.

Particularly advantageous in terms of power transmission is a hitch which has a central spherical element in the common central intersection of the pivot axes of the spherical mechanism. The central ball element is material or positively connected to the ball bar or with the central connecting member and can be held in shell elements which are fastened to the frame member. In rest position and position of use, this central element serves as a central holder. During the movement between both end positions, the central element is co-rotated.

The operating forces are relatively large, especially during the use phase of the hitch. The central element allows a direct application of force from the ball bar in the frame and at the same time reduces the forces absorbed by the links. Through the use of the central element, both the links and its pivot bearing can be made smaller or lighter, which in turn means a positive impact on the necessary space.

The locking of the ball rod in the rest position and position of use can be made very stiff by creating actuators form-fitting connection between the frame and the central element. The links and their hinges can be made particularly small or light because the operating forces are introduced on the ball rod directly into the frame. The positive connection between the frame and the central element thus allows a reduction of the space and the use of inexpensive swivel joints. The actuators and the locking elements arranged therefor can be driven both rotating and sliding.

Particularly advantageous is the design of the described positive actuators in the form of a bolt. The production of such actuators is particularly inexpensive.

A particularly advantageous positioning of the Betätigungsorgaπe the locking device coincides with the position of the pivot axes of the connection points of the frame with the connecting members. The simple hinges are made in this case of the combination of hollow shafts and bushings. This positioning of the actuators allows a very compact design of the hitch and the locking device.

The actuating forces of the locking device can preferably be kept low by means of tapered, displaceable locking elements in comparison to the holding forces of the actuators. The movement of the locking elements causes a penetration of the actuators in their locking position. A particularly advantageous embodiment of the locking element in which the locking element has a backdrop in which the end of the Actuator is held, allows a positive contact of the locking element with the actuator. Any movement of the locking element leads to a movement of the actuator which can be dispensed with force-introducing elements such as mechanical springs.

The individual belonging to the actuators of the locking device locking elements can be connected in one embodiment via a ring segment or via traction means (chain, timing belt, cable or belt), so that the locking elements can be actuated simultaneously.

In a particularly advantageous embodiment, all locking elements can be combined to form a ring segment. The Riπgsegmeπt is arranged around the central point. The inner race of the ring segment has no constant diameter. Rather, the distance to the central point is characterized by a constantly changing radius. A rotation of the ring segment about the central point causes a change in the radial distance between the ring segment and the central ball element in the region of the actuators. The actuators are moved during the rotation of the circular segment radially in the direction of the central point for the realization of the positive or non-positive contact and the locking or unlocking of the hitch.

In a particularly cost-effective embodiment, the locking elements can be connected to each other by traction means such as cable, chain strap or belt.

Particularly advantageous is the embodiment in which a single drive is sufficient for the pivoting of the ball bar and the subsequent locking. One possibility for realizing this embodiment variant is the Maltese transmission described above. A further embodiment variant has a toothing on the towing device and the locking device on the first then comes into engagement when the lock has been lifted and a pivoting may take place. The use of a single drive reduces the cost, space and complexity of the entire device.

Embodiments of the invention are illustrated in the following figures, in which:

Figure 1: a hitch in the use position

Figure 2: the items crank (1), coupling (2) and rocker (3)

Figure 3: a hitch without central element

Figure 4: a hitch in the rest position

Figure 5: a hitch with additional storage

Figure 6: the items Maltese drive member (20), Malteserabtriebsglied (24)

Figure 7: the operating conditions of the Geneva drive

Figure 8: a sectional view of the additional bearing

Figure 9: a sectional view of the bearing points of the connecting members with

actuator

FIG. 10: partial circular locking elements

Figure 11: wedge-shaped locking elements

Figure 12: a hitch in the operating position

Figure 13: a hitch without frame member

FIG. 14: the individual parts actuating element (42) and bearing bush (43)

Figure 15: a hitch including locking device

Figure 16: a side view of the hitch in the position of use

FIG. 17: a side view of the towing device in the movement region 1

FIG. 18 is a side view of the hitch in the range of motion 2

Figure 19: a side view hitch in the rest position

Figure 1 shows an embodiment of a hitch according to the invention in the position of use. The towing device comprises the connecting links crank (1) and rocker (3) which connect the ball rod (6) pivotally connected to components of the frame (4). The frame components (4 and 5) are made with the help of others Frame components, which are not shown here for reasons of clarity, firmly connected to the body of the motor vehicle. The ball rod (6) comprises a standardized coupling ball (7) and is material or form-fitting with another connecting member, the coupling (2).

The connection points of the connecting links crank (1) and rocker (3) with the frame member (4) and the coupling (2) are designed as simple pivot bearing and constructed of bearing pin (8) and bearing bushes (9). The bearing pins (8) of the connection points between coupling (2) and connecting links crank (1) and rocker (3) are in a central element (10), fixed in the form of a sphere.

The ball element (10) is mounted in spherical shells (11). In the operating position, forces introduced on the coupling ball (7) can be introduced directly into the frame components (4) and the body of the motor vehicle. During the movement phase, the ball element (10) is co-rotated.

Figure 2 shows the components crank (1), coupling (2) and rocker (3). The angles between the bore axes are all smaller than 90 ° in the embodiment. A change in the angle allows adaptation of the movement of the ball rod to the space restrictions of the motor vehicle.

Figure 3 shows an embodiment of a hitch according to the invention without central element in the position of use. The operating forces are introduced via the connecting links crank (1), coupling (2) and rocker (3) in the frame members (4) and the body of the motor vehicle.

Figure 4 shows an embodiment of a hitch according to the invention in the rest position. The ball rod (6) and the coupling ball (7) are located almost in the vehicle vertical plane (13) transversely to the vehicle longitudinal axis (12). In the rest position, the inertia and inertial forces in part by means of the central element (10) and the bearing shells (11) in the frame members (4) and the Body of the motor vehicle passed. The hatched area (14) provides space for another bearing shell.

FIG. 5 shows an exemplary embodiment of a towing device according to the invention with a third bearing point (15) of the central element. In addition, the figure shows the position at which the Geneva drive member (20) and the Geneva drive member (24) are mounted at an axial distance.

Figure 6 shows a Maltese cross gear which is used for locking and pivoting the hitch. The Maltese drive member (20) is characterized by three at the same distance from the central axis (21) arranged bolt (22) and a concentric to the central axis (21) arranged, partially cylindrical locking element (23). The Maltese drive member is connected either directly to the motor or the manually driven drive shaft or to the output member of an intermediate transmission. The Maltese output member (24) is characterized by three radially arranged grooves (25) and a matching to the blocking element (23) of the Maltese drive member (20) arranged partially cylindrical recess (26) in the end face of the Malteseer drive member (27). The Geneva drive member (24) is directly connected to the driven link (1) of the hitch.

Figure 7A shows both Maltese links engaged. The blocking element (23) of the Geneva drive member (20) engages in this situation in the partially cylindrical recess (26) of the Maltese output member (24). None of the pins (22) of the Geneva drive member (20) at this time is engaged with the grooves (25) in the Geneva pickup member (24). FIG. 7B shows the Geneva transmission with a Geneva drive member (20) rotated at an angle relative to the starting position (FIG. 7A). In this situation, the pin (22) of the Geneva drive member (20) enters the groove (25) of the Geneva drive member. At the same time, the locking member (23) of the Geneva drive member (20) loses contact with the partially cylindrical recess (26) of the Geneva drive member (24). The Maltese power takeoff has not turned further in this situation. Figure 7C shows the situation in which the Maltese output member has rotated by an angle. In this situation, the second pin (22) of the Geneva drive member (20) enters a groove (25) of the Geneva drive member (24). At the same time, the first pin (22) of the Geneva drive member (20) loses contact with the first groove of the Geneva drive member (24). The Geneva drive member (24) has been pivoted at an angle in the opposite direction to the Geneva drive member (20).

FIG. 7D shows the Geneva transmission in which the hitch is in the rest position. In this situation, the last pin (22) of the Geneva drive member (20) is retracted in the third groove (25) of the Geneva drive member (24). If even larger drive angle are desired, the locking element (23) after further rotation of the Maltese drive member (20) with the teilzylind-cylindrical recess (26) in the Maltese output member (24) come into engagement.

FIG. 8 shows the additional bearing point of the ball element (10) in section. It is like the other bearings constructed of a shell element (11), which is pressed by means of a bolt (8) on the spherical central element (10), to the bolt (8) with an external thread relative to the frame member (4) with a Internal thread axially adjustable. In addition, the bolt (8) is made hollow. In the bore of the bolt (8) is another pin (51) is positioned, which is introduced after pivoting of the hitch in the recess (52) of the central element (10) and thus prevents pivoting of the hitch about all axes. A complete prevention of pivoting of the hitch requires either the use of the Maltese cross transmission described above or another actuator (51).

Figure 9 shows the possibilities for positioning an additional actuator. These offer themselves at the connection points of the connecting links, crank (1) and rocker (3) with the frame components (4). Here the bearing pins (8) are hollow and serve to receive an actuating element (51).

FIG. 10A shows a particularly advantageous locking device. The central element (10) is surrounded by a plurality of actuators (51). A locking element (56) in the form of a ring segment is in direct contact with the actuators (51). The rotation of the locking element (56) causes a displacement of the actuators (51) in the direction of the central element (10) due to the bulges (57) of the tread of the locking member (56).

FIG. 10B shows the construction shown in a circle (FIG. 9A) in detail. The leadership of the actuators is taken from the frame member (4). After the rotation of the locking member (56) and the locking of the central element (10) there is a positive connection of the central element (10) with the frame member (4).

FIG. 10C shows the locking device (FIG. 9B) in the locked state. After the rotation of the locking element (56) and the locking of the central element (10) there is a positive connection of the central element (10) with the frame member (59).

FIG. 11A shows a further advantageous possibility of actuating the locking device. Instead of a curved adjusting element wedge-shaped locking elements (56) are used individually to the actuators (51), which are displaced relative to the frame member (4) and move the actuators (51) in the direction of the central element (10).

FIG. 11B shows the second locking device in the locked state. Instead of a rotation of the curved adjusting member are individually to the actuators (55) wedge-shaped locking elements 56 linearly. The displacement of the locking elements (56) causes a positive locking of the hitch. Figure 12 shows a further particularly advantageous embodiment of a hitch according to the invention, in which a very strict division of tasks with respect to pivoting of the hitch and supporting the operating forces in use and rest position is achieved. The towing device comprises the connecting links crank (1) and rocker (3), which connect the ball rod (6) pivotally connected to a component of the frame (4). The frame member (4) is not closed on the side facing away in Figure 12 and thus allows the pivoting of the ball rod (6) from the use in the rest position.

With the help of other frame components which are not shown here for reasons of clarity, the frame member (4) is firmly connected to the body of the motor vehicle. The ball rod (6) is integrally connected at one end with a standard coupling ball (7) and at the other end with a central element (10) in the form of a ball. The connection points of the connecting links crank (1) and rocker (3) with the frame member (4) and the central element (10) are designed as a simple pivot bearing. The pivot bearings comprise a bolt (8) and a sliding bearing (9) mounted in the connecting links crank (1) and rocker (3).

Because no or relatively small operating forces on the connecting elements crank (1) and rocker (3) in the frame member (4) are introduced in the embodiment during the use and rest position, they can be made very easily. The design of the pivot bearing with respect to power transmission and manufacturing tolerances is subjected to much less stringent requirements. Basically, this leads to a reduction in manufacturing costs. The forces arising in the position of use and rest are conducted into the frame component (4) with the aid of shell elements (11). The shell elements (11) can be positively, materially or non-positively connected to the frame member (4). The holes 36 in frame member (4) are used to carry out the actuators (51). FIG. 13 shows the towing device without frame component (4). The embodiment of the hitch of the type described includes three shell elements (11) for supporting the central element (10). However, the number of shell elements (11) is free, unless the central element can not be pushed out of storage due to the operating forces.

In the central element (10) further bores (41) are mounted in the position of use collinear to the holes (36) in the frame member (4) of Figure 12 are arranged. The manufacturing tolerances of the bolts (8) and sliding bushes (9) of the pivot bearing are designed such that the shell elements (11) determine the position of the central point. The pivoting of the hitch between the use and rest position thus can not lead to jamming of the device.

Figure 14 shows an actuator (51) and the associated bearing bush (43). The actuator has a frusto-conical shape at one end. This shape also has the bore (41) in the central element (10).

Figure 15 shows the embodiment of the hitch invention including a locking device. The locking device includes actuators (51) which are connected to a drive member (45). The actuators (51) are also movably mounted in the frame member (8) by means of the bearing bushes (43). The drive member (45) is either driven by a motor or manually and moved in the direction of the central element (10). The transmission of the pushing movement on the connecting link crank (1) is realized by means of a toothing (47) and (48) of the drive or the connecting link crank (1).

The toothing (47) of the connecting link crank (1) is limited to a part of the circumference. The toothing (47) or (48) of both parts is engaged only during pivoting of the ball rod (6) between the use and rest position. Once the use position of the hitch is reached, the meshing engagement is released and the drive member (45) can be moved further be without causing movement of the link crank (1). In this last phase of the movement of the drive member (45), the actuators (51) are moved so far in the direction of the central element (10) that they penetrate into the bores (41) of the central element (10). Due to manufacturing tolerances, a minimum of three of the four actuators (51) should be able to be positioned relative to the drive member (45). The. relative positioning of the actuators (51) allows the simultaneous engagement of all elements in the associated bores (41) in the central element (10).

FIG. 16 shows the side view of the hitch according to the invention in the position of use. The ball bar (6) and coupling ball (7) protrude below the rear bumper (60) of the motor vehicle. All other components are not visible by an observer behind the motor vehicle. The adjustment movement is realized by a pure rotational movement of the rocker (3) and can be divided into three movement areas which merge seamlessly into each other.

Figure 17 shows the side view of the hitch according to the invention in a pivoted state. The first movement range, starting from the use position of FIG. 14, is characterized in that the coupling ball (7) is pivoted downwards from the standardized operating height. Because all points of all moving parts during the pivoting of the hitch describe tracks lying on concentric spherical surfaces, the coupling ball moves not only down but also in the direction of the vehicle rear and the vehicle side. The last two movements are relatively small, especially at the beginning of the pivoting process. The adaptation of the movement of the ball rod (6) to the space restrictions of the relevant motor vehicle is done by changing the angle between the axes of rotation of the connecting links, crank (1) and rocker (2), the angle between the axes of rotation of the frame members (4) and the angle between the axes of rotation of the coupling (2). FIG. 17 shows the side view of the towing device according to the invention in a further pivoted state. The further the coupling ball 7 (or 33) is lowered, the greater the proportions of the movements in the direction of the rear of the vehicle. In the second movement range, the coupling ball (7) is moved so that it is located under the rear bumper (60) of the motor vehicle.

Figure 18 shows the side view of the hitch invention after the pivotal movement has been completed and the hitch is in the rest position. In the last range of motion, the coupling ball (7) is moved above all in such a way upward and in the lateral direction that it is located in this position in the cavity behind the rear bumper of the motor vehicle. This rest position is very advantageous because it does not affect the depth of the trunk of the motor vehicle.

Claims

claims

1. A hitch for motor vehicles, which is arranged fixed to the vehicle via a frame member and a ball bar (6) which is pivotable from a use in a rest position and vice versa, characterized in that the ball bar (6) about a central point (37) and about a non-fixed axis extending through the central point (37) is pivotable and the first and a second link (1, 3, 28, 30) are rotatably mounted on the frame member and that the ball bar (6, 32) via a third link (2) is rotatably connected to the first and the second link (1, 3, 28, 30), wherein the axes of rotation of all links intersect at a central point (37).

2. Hitch device according to claim 1, characterized in that at least one of the connecting members (1,3,28,30) is driven by a motor or manually.

3. Hitch device according to claim 2, characterized in that a motor drive takes place directly or via a Maltese cross gear in which a drive member (20) has a specific center distance to the axis of rotation of a driven member (24) which is directly connected to a connecting member (1, 3, 28, 30), wherein a bolt (22) arranged on the drive member (20) can be introduced into a groove (25) of the driven member (24) such that the driving motor shaft movement causes the driven connecting member (1, 3) to rotate , 28, 30) and upon release of the pin (22) from the groove (25) locking elements (23, 26) of the drive member (20) and driven member (24) are inserted into each other, whereby further pivoting of the connecting member (1, 3, 28, 30) is prevented.

4. Towing device according to claim 1, characterized in that it is manually driven by one of the connecting members (1, 3, 28, 30) and / or the ball bar (6, 32) by hand between the rest position and use position is pivotable.

5. Towing device according to one of the preceding claims, characterized in that in the rest position and in the position of use, a locking mechanism, in particular manually, can be unlocked or locked.

A towing device according to any one of the preceding claims, characterized in that the central point (37) forms the center of a central ball element (10) serving as a central support which pivots about the central point (37) due to its attachment one of the connecting members is mitrotierbar and on the ball surface at least one pivot pin (8) is supported, which forms the axis of rotation of another link.

7. Towing device according to claim 6, characterized in that the

Ball element (10) by means of at least one pivot pin (8) is attached to a connecting member.

8. Trailer coupling device according to one of the preceding claims, characterized in that the third connecting element (2) is designed as a central point (37) arranged central ball element (2), wherein the ball element is rotatably held in at least partially spherical shell-shaped holding elements, which are attached to the frame member.

9. Towing device according to one of the preceding claims, characterized in that via at least one actuating member (51) in the rest position and position of use, a positive or non-positive connection between the frame member and the central ball element (2,10) can be produced.

10. Towing device according to one of the preceding claims, characterized in that the at least one actuating member is designed as a pin (51) which is retractable in the central ball element (2, 10), in particular wherein a pin (51) coaxial in a pivot pin (51). 8) is arranged.

11. Towing device according to one of the preceding claims, characterized in that at least one actuating member (51) via a conically tapering, displaceable locking element (56) is actuated such that it can be guided in the movement of the locking element (56) in a locking position, and in particular can be released from the locking position via a positive and / or non-positive connection between the locking element and actuator.

12. Hitch device according to claim 11, characterized in that a plurality of locking elements (56) are provided, which are coupled to each other such that all locking elements (56) are simultaneously actuated.

13. Trailer hitch according to one of the preceding claims, characterized in that the coupled locking elements (56) are rotationally or slidingly actuated.

14. A towing device according to one of the preceding claims, characterized in that the coupled locking elements (56) are formed as a around the central point (37) arranged / arranged ring / ring segment having an inner running surface (57), with the the ends of the actuators (51) are displaceable by rotation of the ring / ring segment in the axial direction of the actuators (51).

15. Towing device according to one of the preceding claims, characterized in that the locking elements (61) via pulling means, in particular a chain, toothed belt, cable, tape are interconnected.

16. Towing device according to one of the preceding claims, characterized in that the drive of the at least one locking element via a motor, which is provided for pivoting.