Towing drawbar, trailer and vehicle combination

Abstract

Towing drawbar, via which a trailer can be coupled to a towing vehicle so that the trailer can be towed by the towing vehicle, with two drawbar links (1, 2), wherein one of the drawbar links (2) can be connected to the trailer and the other drawbar link (1) to the towing vehicle, wherein a connecting element (3) is provided which connects the two drawbar links (1, 2) to each other in a connection position (V) and which is secured in the connection position (V) by a locking device (4), wherein the connecting element (3) is pre-tensioned by a spring (5) into a release position (F) which releases the connection of the two drawbar links (1, 2) and wherein the locking of the connecting element (3) can be released by actuating the locking device (4), so that the connecting element (3) is automatically moved into the release position (F) for emergency uncoupling of the trailer from the towing vehicle due to the pre-tension.characterized in that at least one drawbar member (1, 2) is arranged between the spring (5) and the locking device (4).

Description

[0001] The invention relates to a towing drawbar via which a trailer can be coupled to a towing vehicle, so that the trailer can be towed by the towing vehicle.

[0002] Towing drawbars are typically used to transfer power between two vehicles, allowing one to tow, pull, or push the other. The towing vehicle is called the towing vehicle, and the towed vehicle is called the trailer. The trailer may not have its own drive and therefore relies on the towing vehicle for propulsion. However, it's also possible that the trailer could move independently, but is still intended to be propelled by the towing vehicle. This might be the case, for example, if the trailer's drive system is broken and it needs to be towed. Furthermore, it may be planned that the trailer is first towed to a work site by the towing vehicle and then moved there using its own drive system.

[0003] To move the trailer using the towing vehicle, the tow bar must allow for power transmission between the towing vehicle and the trailer. The tow bar is connected to the trailer at one end and detachably to the towing vehicle at the other. The towing vehicle typically has a standardized interface, such as a trailer hitch, for attaching the trailer to the towing vehicle via the tow bar.

[0004] Furthermore, there are trailers that can only be pulled and pushed using the tow bar and may have their own steering mechanism, as well as those that can also be steered using the tow bar and therefore do not require separate steering. Especially when a trailer has multiple axles, it may be necessary to steer it to follow the towing vehicle, even when cornering. This is also familiar from cars being towed, where the towed vehicle must be actively steered by a person. However, some trailers allow the tow bar to be connected to a steering axle of the trailer, so that the trailer follows the towing vehicle independently, even when cornering. This is familiar, for example, from a truck and trailer combination.

[0005] Although such tow hitches have proven their worth in the past, uncoupling the trailer from the towing vehicle usually requires manually releasing the tow hitch. While this is generally not a major problem in civilian settings, manual uncoupling can pose a significant danger in military operations. This is because it necessitates stopping the vehicle combination, making it an easy target for enemy fire. Especially if, in such a dangerous situation, the trailer has to be manually uncoupled from the towing vehicle, requiring a person to leave the protected interior, there is a considerable risk to life and limb.

[0006] DE 35 32 494 A1 discloses a further development of pre-positioned pins in a known design with a locking pin for engaging conical rings or similar holders, in particular for circular arc pins, in the arrangement of which the end of the handle projects in front of or beyond the center of the pre-positioned pin and has a nose for receiving a compression spring, spacer pin or the like.

[0007] DE 103 22 933 A1 discloses a locking bolt for insertion into a bore of a component, comprising a bolt element and a spring element. The bolt element has a shaft section that can be inserted into the bore and, in the region of its end facing away from the insertable shaft section, a radial transverse bore and a substantially axially oriented end bore. The spring element comprises at least one loop, the first end of which can be inserted into the transverse bore and the second end of which can be inserted into the end bore.

[0008] DE 12 91 213 A relates to a locking device on coupling bolts of vehicles, in particular for trailer couplings of agricultural vehicles, in conjunction with an electrical cable connection, which allows the coupling bolt to be loosened only after the electrical cable connector has been loosened.

[0009] DE 19 63 460 U discloses a device on transport wagons for automatic uncoupling from conveyor drag chains.

[0010] The invention aims to provide a towing drawbar with which the trailer can be reliably uncoupled from the towing vehicle in an emergency situation.

[0011] This problem is solved in a towing drawbar of the type mentioned above by the fact that the towing drawbar has two drawbar links, one of which can be connected to the trailer and the other to the towing vehicle, a connecting element is provided which connects the two drawbar links to each other in a connecting position and which is secured in the connecting position by a locking device, the connecting element being pre-tensioned into a release position which releases the connection of the two drawbar links and the locking of the connecting element can be released by actuating the locking device, so that the connecting element is automatically moved into the release position for emergency uncoupling of the trailer from the towing vehicle due to the pre-tension.

[0012] The ability to separate the two drawbar sections in an emergency eliminates the need to detach the towbar from the towing vehicle to uncouple the trailer. Instead, in an emergency, one drawbar section remains connected to the towing vehicle and the other to the trailer. This detachable drawbar section provides an additional, reliable method for uncoupling the trailer in an emergency, alongside the standard method of disconnecting the towbar from the towing vehicle.

[0013] In normal operation, the two drawbar sections are connected by a linking element, thus enabling power transmission between the towing vehicle and the trailer, allowing the trailer to be pulled or pushed by the vehicle. The towing drawbar therefore ensures a power flow from the towing vehicle through one drawbar section to the linking element, and from there to the other drawbar section and finally to the trailer, or vice versa.

[0014] The locking device secures and holds the connecting element in the position that joins the two drawbar sections. This ensures a reliable connection between the two drawbar sections via the connecting element, preventing them from unintentionally separating during normal operation and maintaining the flow of force. However, the connecting element is also pre-tensioned to a release position, so that in an emergency, the force required to separate the two drawbar sections is already provided by the pre-tension and simply needs to be released. This pre-tensioning of the connecting element ensures that the two drawbar sections can be separated very quickly and without significant additional effort.

[0015] To uncouple the trailer from the towing vehicle in an emergency, it is only necessary to release the locking mechanism of the coupling element in the connected position. When the locking mechanism no longer secures the coupling element, the pre-tension essentially moves it abruptly into the release position, in which the two drawbar sections are no longer connected via the coupling element and the trailer is thus uncoupled from the towing vehicle. Due to the pre-tension force already present during normal operation, the coupling element automatically moves into the release position when the locking mechanism is released.

[0016] With regard to the two drawbar sections, it has proven advantageous if one drawbar section is located on the towing vehicle side and the other on the trailer side. The drawbar section on the towing vehicle side, hereinafter also referred to as the first drawbar section, may have connecting means for connection, in particular for a detachable connection, to the towing vehicle. For example, the drawbar section on the towing vehicle side may have an annular towing eye. The corresponding connecting means may be designed such that the drawbar section can be connected to a standard towing vehicle interface for coupling a trailer, such as a trailer hitch. The corresponding connecting means may be located at the end of the drawbar section on the towing vehicle side opposite the drawbar section on the trailer side, and thus in the towing vehicle-side end region of the towing drawbar.The drawbar link on the trailer side is also referred to below as the second drawbar link.

[0017] According to an advantageous embodiment of the invention, it is proposed that the connecting element be designed as a connecting bolt. The design as a connecting bolt enables reliable force transmission between the two drawbar links in the connected position. When the towing vehicle is pulling the trailer, the connecting element may be subjected primarily to shear stress. Therefore, the connecting element can be designed primarily to withstand such stress. The connecting element can be made of steel, in particular high-alloy steel, to meet the corresponding requirements.

[0018] Regarding the orientation of the connecting element, it has proven advantageous for it to extend vertically in the connected position. This design allows not only the preload force to act on the connecting element, but also the force of gravity to push it into the release position, ensuring a reliable separation of the two drawbar sections. Furthermore, the vertical orientation of the connecting element ensures that it reliably connects the two drawbar sections even when driving over uneven terrain. This is because the vertical orientation allows the connecting element to absorb torques around a transverse axis parallel to the ground.

[0019] It has also proven advantageous to secure the connecting element against loss with a safety cable. A suitable safety cable ensures that the connecting element is not lost when being moved into the release position, but remains connected to the tow bar via the safety cable even in the release position. Therefore, if the two drawbar sections have been uncoupled in an emergency, they can also be reconnected using the same connecting element.

[0020] According to the invention, the connecting element is pre-tensioned into the release position by a spring. The spring can be designed as a coil spring, and the pre-tension force can be dimensioned such that reliable movement of the connecting element from the connected position to the release position is ensured in the event of an emergency uncoupling of the trailer from the towing vehicle. The use of a leaf spring is also possible.

[0021] Especially when the trailer becomes jammed or snagged and the towing vehicle exerts a pulling force on the trailer, the connecting element between the two drawbar links can become jammed. If the spring force, possibly in combination with gravity, is then insufficient to move the connecting element into the release position, briefly relieving the tension on the tow bar may be enough to release the connection and thus achieve emergency decoupling. This can occur, for example, due to load changes, such as jolting while driving over uneven road surfaces. Even when stationary, with the two drawbar links largely free of force, emergency decoupling can be achieved without significant problems.

[0022] Furthermore, it has proven advantageous with regard to the connecting element if the spring preload acts in the longitudinal direction of the connecting element. When the locking device is released, the longitudinally acting spring preload can move the connecting element axially from the connected position to the released position. The connecting element can essentially extend in the axial direction, so that the preload acts in the direction of the connecting element's greatest geometric extent. The connecting element can thus be moved linearly from the connected position to the released position. Such a movement is, for example, less prone to errors than a rotational movement.

[0023] From a design perspective, it has proven advantageous for the connecting element to have a radially projecting shoulder that serves as a support for the spring. The spring force, acting longitudinally or axially, can be transferred into the connecting element via this shoulder, ensuring that it reliably moves into the release position in the event of an emergency disconnection. If the spring is a helical spring, it can surround the connecting element, allowing the connecting element to be positioned within the spring. This ensures a uniform force distribution around the circumference of the connecting element.

[0024] Regarding the arrangement of the spring and the locking device, it has proven advantageous for the spring to act at one end of the connecting element and the locking device at the opposite end. This ensures a compact design. The connecting element is particularly rigid and therefore not easily deformable, so securing the end of the connecting element opposite the spring also ensures that it is not moved by the spring's force. For example, the spring can act at the lower end of the connecting element, and the locking device can secure the connecting element at the upper end.In this context, it has also proven advantageous if the spring and the locking device are positioned opposite each other with regard to the arrangement of the connecting element, which has also proven advantageous with regard to a compact design. According to the invention, at least one drawbar link is arranged between the spring and the locking device. The spring can thus be supported at one end on the shoulder of the connecting element and at the opposite end on the outside of a drawbar link, in particular the first drawbar link.

[0025] In a constructive further development of the invention, it has proven advantageous with regard to the two drawbar sections if they are interlockable. Each of the two drawbar sections has a connection area, and these two connection areas can be connected to each other, in particular by axial interlocking. One of the drawbar sections, in particular the second drawbar section, can have a male connection area, and the other drawbar section, in particular the first drawbar section, can have a female connection area, so that the two drawbar sections can be interlocked accordingly.

[0026] Furthermore, it has proven advantageous if one drawbar link has a tubular cross-section and the other drawbar link can be axially inserted into it. In particular, the first drawbar link has a tubular cross-section. The outer diameter of the inserted drawbar link can correspond to the inner diameter of the other drawbar link. This ensures that the two drawbar links are not movable relative to each other in the radial direction, but rather are positively connected to each other in the radial direction. If the two drawbar links are not yet connected to each other via the connecting element, they are movable relative to each other in the axial direction. This movement is then prevented by the connecting element.The connection area of ​​the drawbar link, in particular of the second drawbar link, can be designed in the manner of an axial projection that can be inserted into the connection area of ​​the other drawbar link in an axial direction.

[0027] To connect the two drawbar sections, it has proven advantageous for each section to have a receptacle for the connecting element. The two drawbar sections can thus be positively connected via the connecting element. This ensures a particularly reliable power transmission between the towing vehicle and the trailer via the towing drawbar or the two drawbar sections. The receptacles can be located in the end connection area of ​​each drawbar section. The connection areas can be located in the end section of each drawbar section that faces the other. With regard to the connection to the towing vehicle or the towing eye, the connection area can therefore be located in the end section opposite the connection.

[0028] For connecting the two drawbar sections, it has proven advantageous if the receptacles can be aligned when the sections are inserted, so that the connecting element can engage through the receptacles of both sections in the connected position. The connecting element can thus extend through both receptacles, ensuring a positive-locking connection between the two drawbar sections. If the two drawbar sections are pulled apart by a longitudinal tensile force, this force is transmitted via one of the two drawbar sections to the connecting element, which is then subjected primarily to shear stress, and from there to the other drawbar section.

[0029] With regard to the receptacles, it has proven advantageous for them to have a free cross-section that is at least equal to the diameter of the connecting element. This design allows the connecting element to be easily inserted through the two drawbar sections, particularly by hand. The receptacles can be designed as through holes whose inner diameter can essentially correspond to the outer diameter of the connecting element. This also ensures that the connecting element does not become jammed when inserted.

[0030] It has also proven advantageous if the two interconnected drawbar sections are designed to be relatively rotatable relative to each other about a longitudinal axis. This relative rotatability ensures that the trailer can also rotate around a corresponding longitudinal axis relative to the towing vehicle. On normal roads, such rotation around the longitudinal axis, or such torsion of the trailer relative to the towing vehicle, is generally not necessary. Therefore, it only really plays a role on uneven terrain with a certain degree of lateral slope. This relative rotatability thus prevents the towing drawbar from being damaged by high torsional forces, or high torsional forces from the trailer being transmitted to the towing vehicle or the towing vehicle interface. The corresponding longitudinal axis can extend centrally through the two drawbar sections and be arranged parallel to the ground.Furthermore, the longitudinal axis can essentially correspond to the direction of travel if the towing vehicle is traveling straight ahead.

[0031] With regard to relative rotation, it has proven advantageous if one of the two drawbar links is fixed and the other drawbar link is designed to rotate relative to the fixed drawbar link. In this respect, it is possible for only one of the two drawbar links to be rotatable about the longitudinal axis, while the other drawbar link is correspondingly fixed. The first drawbar link being fixed is advantageous because the connection point for coupling the trailer to the towing vehicle also allows no or only very slight rotation about a longitudinal axis. While the second drawbar link can be fixed about the longitudinal axis relative to the trailer, the fact that the trailer, especially when traveling on uneven terrain with a cross slope, can rotate relative to the towing vehicle about its longitudinal axis can then also cause the two drawbar links to rotate relative to each other.From a structural point of view, the tubular drawbar link can function as a pivot bearing for the drawbar link inserted into the tubular drawbar link.

[0032] With regard to relative rotation, it has proven advantageous for the two drawbar links to be rotatable within a predetermined angular range around the longitudinal axis. This predetermined angular range ensures, on the one hand, that torsional forces in the towing drawbar are kept to a minimum, while on the other hand, sufficient stability of the coupling between the trailer and the towing vehicle is achieved, preventing the trailer from tipping over, for example, when driving over uneven terrain with a cross slope. Furthermore, the rotatability of the two drawbar links ensures that bearing forces are kept to a minimum, so that they do not impede the movement of the connecting element from the connected position to the released position.It has proven advantageous if the two drawbar links are relatively rotatable relative to each other within an angle range of ± 15 degrees; that is, the trailer, together with the drawbar link on the trailer side, can rotate 15 degrees clockwise and 15 degrees counterclockwise around its longitudinal axis from the neutral position. A total rotation of 30 degrees is thus possible.

[0033] From a design perspective, it has proven advantageous if one of the two drawbar links has two opposing tapers to allow relative rotation. Advantageously, the second drawbar link has corresponding tapers in the area of ​​the receptacle. These can be designed as notches, grooves, or milled recesses, particularly as V-shaped notches, grooves, or milled recesses. The tapers could converge towards the central axis of the drawbar link, so that the free cross-section increases radially outwards from the center. The smallest free cross-section of the corresponding receptacle of the drawbar link can therefore be located in the center, and this can correspond to the outer diameter of the connecting element. The cross-section of the drawbar link can be axially symmetrical. The connecting element can be rotationally fixed to the vehicle-side drawbar link.

[0034] With regard to the tapering, it has proven advantageous for the drawbar to have two flanks arranged at an angle to each other. In particular, the two flanks are arranged symmetrically to each other, ensuring symmetrical relative movement of the two drawbar sections. The two flanks can, for example, form an angle of 30 degrees with each other, thus allowing a relative movement of 15 degrees in each direction. It is advantageous for the flanks to be straight.

[0035] According to a constructive refinement, it has proven advantageous for one flank of one taper to meet the other at a contact point. This contact point can therefore be located in the middle of the drawbar link, and since each taper can have two flanks, a left contact point and a right pivot point can be provided.

[0036] Furthermore, it has proven advantageous with regard to the sides if they are designed as stops that limit the relative rotation of the two drawbar sections. These stops ensure that the two drawbar sections can only rotate relative to each other within a predetermined angular range. This provides sufficient driving stability for the trailer and also ensures that any torsional forces occurring in the towing drawbar remain within manageable limits.

[0037] According to a further advantageous embodiment, it is proposed that the connecting element be rotatable relative to one of the drawbar links with respect to the other drawbar link. The connecting element can thus be rotatably coupled to one drawbar link and then rotate together with it relative to the other drawbar link. Advantageously, the connecting element is rotatably coupled to the second drawbar link and then rotatable together with the second drawbar link about the longitudinal axis relative to the first drawbar link.

[0038] In this design, it has proven advantageous if the recess of the fixed drawbar link is shaped like an elongated slot, which allows relative movement of the connecting element. The connecting element can thus be rotated together with one of the drawbar links, and in doing so, the connecting element can move back and forth within the elongated slot. The ends of the elongated slot can then act as stops to limit the relative rotation of the two drawbar links.

[0039] Regarding the placement of the safety device, it has proven advantageous to position it on the outside of one of the two drawbar sections. This arrangement allows for a very compact design. At the same time, the safety device remains easily accessible from the outside, thus facilitating simple maintenance.

[0040] With regard to the locking device, it has proven advantageous if it includes a locking element that can be moved back and forth between a locked position and an unlocked position in a locking direction. The locking element can be movable parallel to the longitudinal axis of the drawbar sections. The movement between the locked position and the unlocked position can be perpendicular to the movement of the connecting element between the connection position and the release position. The locking element can be movable back and forth on the outside of one of the two drawbar sections, particularly on the outside of the first drawbar section. When the locking device is actuated, the locking element can be moved from the locked position to the unlocked position.

[0041] It has also proven advantageous if the force required to release the locking device is less than the preload force acting on the connecting element. This design significantly reduces the force required to release the two drawbar links. This is because the preload force required to move the connecting element from the connected position to the release position is already provided when the two drawbar links are connected via the connecting element. In the event of an emergency release, it is then only necessary to release this force by disengaging the locking device.The preload required to drive out the connecting element is stored in the spring, and this can then be released by unlocking the connecting element through the actuation of the locking device in such a way that the connecting element is essentially pulled abruptly out of the receptacles of the drawbar links and the positive locking connection of the two drawbar links is terminated.

[0042] With regard to the locking element, a wedge-shaped design has proven advantageous. The wedge shape ensures that, when the locking element is released from the locked position to the unlocked position, it cannot become jammed or jammed. Even during a simple transfer, the wedge shape allows the connecting element to move to a certain extent towards the release position. Due to the spring preload, the locking element is thus pre-loaded towards the unlocked position, but it does not move due to friction between the locking element and the connecting element and / or between the locking element and the outer surface of the drawbar link. In the locked position, the locking element can engage the receptacles or...at least partially cover the mounting of a drawbar link, in particular the first drawbar link.

[0043] Furthermore, it has proven advantageous if the locking element, in the locked position, blocks movement of the connecting element into the release position. The connecting element is thus held in the connected position by the locking element, ensuring a reliable connection between the two drawbar sections.

[0044] With regard to the design of the connecting element, it has proven advantageous for it to have a recess, particularly a slot-shaped one, in which the locking element is positioned in the locked position. This recess allows for a positive-locking connection between the locking element and the connecting element. The recess can extend through the entire connecting element parallel to its longitudinal axis. When the locking element is positioned in or engages within the recess, vertical movement of the connecting element is prevented, thus securing it in the connected position. The locking element can have a plate-like geometry and its thickness can be adapted to the width of the recess.

[0045] To release the locking element, it has proven advantageous if the locking element can be pulled out of the recess of the connecting element. The locking element can be moved linearly parallel to the longitudinal axis, and after leaving the recess, the connecting element can then be moved independently out of the openings of the two drawbar links into the unlocked position due to the acting preload force. The directions of movement of the locking element and the connecting element are at right angles to each other.

[0046] With regard to the locking device, it has also proven advantageous if the locking element is pre-tensioned into the locked position. The locking element can be pre-tensioned into the locked position by a spring.

[0047] In this context, it has proven advantageous if the locking element can be moved into the unlocked position against the spring's preload force. The spring force that preloads the locking element into the unlocked position can be overcome, and the locking element can be pulled into the unlocked position. If no force is applied to the locking element, it moves towards the locking position that secures the connecting element due to the preload force.

[0048] From a design perspective, it has proven advantageous if the locking element can be moved into the unlocked position by means of a pressure cylinder, particularly by pressing it. A pressure cylinder allows for particularly easy movement of the locking element. When the pressure cylinder is pressurized with compressed air, the locking element can be pulled out of the recess of the connecting element, thus releasing it. The pressure cylinder can be designed as a pneumatic cylinder. Alternatively, however, a hydraulically actuated cylinder can also be provided, which can be operated with hydraulic fluid, particularly oil.

[0049] With regard to the pressure cylinder, it has proven advantageous for it to have an interface for connection to a compressed air or hydraulic network, particularly one on the towing vehicle side. This design allows for a very compact construction, as the tow bar itself does not rely on a compressor or pressurized supply. Military vehicles, in particular, typically already have a compressed air and / or hydraulic network. A suitable compressed air network can therefore provide sufficient compressed air to move the pressure cylinder and thus release the locking mechanism. The same applies to a hydraulic network. To supply the pressure cylinder with compressed air, for example, a solenoid valve can be opened from inside the vehicle, allowing compressed air to flow from an air supply line to the pressure cylinder. The air supply line can be kept permanently pressurized for this purpose.

[0050] With regard to unlocking the coupling element, it has proven advantageous if the pressure cylinder is designed to be remotely controllable. The pressure cylinder can thus be operated from a safe distance, for example, from inside the towing vehicle, and pressurized with compressed air or hydraulic fluid. Therefore, it is not necessary for personnel to leave the towing vehicle to uncouple the trailer from the towing vehicle in an emergency.

[0051] With regard to the locking element, it has proven advantageous if it automatically returns to the locked position due to preload when the pressure cylinder is not pressurized with compressed air or hydraulic fluid. In this respect, the connecting element can only be unlocked via the locking device when the pressure cylinder is activated and pressurized with compressed air or hydraulic fluid. Unintentional emergency decoupling can thus be prevented.

[0052] In an alternative embodiment, the locking element of the locking device, which releases the connecting element in the unlocked position, can also be moved by electromagnetic, mechanical, or pyrotechnic actuation. In this way, the connecting element is also released and then moves independently from the connected position to the release position.

[0053] According to an advantageous embodiment of the invention, a locking pin blocks movement of the locking element from the locked position to the unlocked position. The pin can be arranged at the end of the locking element opposite the pressure cylinder, so that the pin and the pressure cylinder are opposite each other with respect to the connecting element. The pin prevents the locking element from being pulled out of the connecting element or out of the recess in the connecting element, thus also preventing the trailer from being uncoupled from the towing vehicle. To enable such uncoupling, the pin must first be removed, particularly by hand.The cotter pin prevents unintentional release of the tow bar, for example, when the trailer is being towed in peaceful territory and normal uncoupling poses no danger. Before military use, however, the cotter pin is removed and the safety device is activated, allowing the two drawbar sections to be uncoupled from each other in an emergency or even while driving.

[0054] According to a constructive refinement, it has proven advantageous if one of the drawbar links has a drawbar fork via which the drawbar link can be connected to the trailer. The drawbar fork can be part of the second drawbar link, and the corresponding drawbar link can be connected to the trailer via this second drawbar link.

[0055] It has proven advantageous for the drawbar to have two drawbar arms, each with a toothed segment at one end, through which the two drawbar arms are connected in a movement-coupled manner. The two drawbar arms cannot move independently of each other; rather, movement of one drawbar arm automatically leads to movement of the other drawbar arm due to the coupling of the two toothed segments. This design ensures high stability and force transmission between the two drawbar arms. This is particularly advantageous when reversing or driving around tight curves, as the forces acting on both drawbar arms can be distributed. Furthermore, the toothed segments prevent the tow bar or drawbar arm from buckling during push-off operation, i.e., when the towing vehicle is pushing the trailer.The drawbar thus acts as a rigid coupling with the trailer and offers no further pivot point.

[0056] With regard to the drawbar, it has proven advantageous to transmit tensile and compressive forces along the bisectors of the drawbar angle. This ensures reliable power transmission, allowing the towing vehicle to move the trailer using both tensile and compressive forces.

[0057] Furthermore, it has proven advantageous if the drawbars can be connected to the trailer at the ends opposite the toothed segments. The connection to the trailer is advantageously rotatable, so that no moments can be transmitted between the trailer and the drawbars. The trailer can have corresponding interfaces for connecting to the drawbars. Since the two drawbars are variable due to the possibility of movement via the toothed segments, the tow bar can also be adapted to different interfaces on a trailer.

[0058] Furthermore, with regard to the drawbar, it has proven advantageous for it to have a retaining element in which the two drawbar arms are rotatably mounted. Advantageously, the two drawbar arms are rotatably mounted in the area of ​​the toothed segments. The retaining element can comprise two plates, one of which can be arranged above the toothed segments and the other below them, so that the drawbar arms are rotatably mounted between the two plates. The retaining element can have a triangular or T-shaped design.

[0059] With regard to the retaining element, it has proven advantageous to equip it with a support foot on its underside. The support foot prevents the corresponding drawbar link from falling to the ground during emergency decoupling, thus preventing damage, particularly to the end connection area. Due to its placement on the underside, only the support foot, which is designed to withstand the corresponding load, comes into contact with the ground.

[0060] It has also proven advantageous if the connection area of ​​the drawbar link with the drawbar fork is located in the end section of the drawbar link opposite the drawbar arms. The corresponding drawbar link can thus be connected on one side to the trailer via the drawbar arms and on the opposite side via the connection area to the other drawbar link or to the connection area of ​​the other drawbar link.

[0061] With regard to the aforementioned task, a trailer for a towing vehicle is further proposed, wherein the trailer is equipped with a towing drawbar designed as described above. This results in the advantages already described above with regard to the towing drawbar.

[0062] The tow bar is advantageously connected to the trailer's frame, so that no steering movement of the trailer is initiated via the tow bar. This simple design is particularly beneficial when the trailer is a tracked vehicle, as it then does not necessarily require its own steering mechanism and can be easily maneuvered by the towing vehicle, even around curves. The trailer can be designed as either a self-propelled vehicle or a vehicle without its own drive. The trailer can be a military vehicle, especially a military tracked vehicle.

[0063] Furthermore, with regard to the aforementioned task, a vehicle combination consisting of a towing vehicle and a trailer is proposed, wherein the trailer is coupled to the towing vehicle via a towing drawbar, and wherein the towing drawbar is designed in the manner described above. The advantages already described with regard to the towing drawbar also apply in this respect.

[0064] The towing vehicle may have an interface for connecting to the tow bar. This can be a standard, particularly a standardized, interface through which a trailer can be coupled to the towing vehicle. If the trailer needs to be uncoupled from the towing vehicle, the coupling between the tow bar and the towing vehicle can be released. This is equivalent to normal uncoupling. Only in an emergency situation can the emergency uncoupling of the tow bar described above be used, in which the two drawbar sections are separated. In the separated position, one drawbar section is then connected to the trailer and the other to the towing vehicle. If the trailer is uncoupled from the towing vehicle in this way, the towing vehicle can continue moving without the trailer, with the drawbar section on the towing side remaining attached to the towing vehicle.The towing vehicle can be a military vehicle, in particular a military wheeled or tracked vehicle. The trailer can be a vehicle, in particular a military vehicle, either with or without its own propulsion, a defective vehicle, or, for example, a drone.

[0065] Further details and advantages of the invention will be described in more detail below with reference to the accompanying drawings of an exemplary embodiment. These drawings show: Fig. 1 a sectional view through the tow bar showing the connection of the two bar links; Fig. 2 a cutaway side view of the tow bar showing the connection of the two bar links; Fig. 3 a view according to Fig. 2, wherein the connecting element connecting the two drawbar links is in a release position and the two drawbar links have been detached from each other for emergency decoupling; Fig. 4 A schematic top view of the towing drawbar, showing both the connection to the trailer and the connection to the towing vehicle.

[0066] In the presentation of the Fig. Figure 2 shows a towing drawbar 10 in a cutaway side view. The towing drawbar 10 is attached to a trailer (not shown in the illustration) and allows the trailer to be coupled to a towing vehicle via this drawbar. To couple the trailer to the towing vehicle, the towing drawbar 10 has a towing eye 1.2 at one end, which is shown in the top view of the Fig. 4. This drawbar eye 1.2 can be connected to a standard interface on the towing vehicle, so that the trailer is then coupled to the towing vehicle. To uncouple, the towing drawbar 10 or drawbar eye 1.2 can be detached from the towing vehicle, and the towing vehicle can then be moved independently of the trailer.

[0067] In addition to the standard decoupling of the trailer from the vehicle, the towing drawbar 10 also offers an emergency decoupling function. This allows the trailer to be quickly detached from the towing vehicle in an emergency, even while driving, without manual intervention. The emergency decoupling function is based on the fact that the towing drawbar essentially consists of three elements: a first drawbar section 1 on the towing vehicle side, a second drawbar section 2 on the trailer side, and a connecting element 3 that positively locks the two drawbar sections 1 and 2 together. Under normal operating conditions, the two drawbar sections 1 and 2 are connected via the connecting element 3, enabling the trailer to be pulled or towed by the towing vehicle and ensuring a continuous flow of force between the towing vehicle and the trailer via the towing drawbar 10.When the towing drawbar 10 is uncoupled in an emergency, the two drawbar sections 1 and 2 are separated from each other in the manner described in more detail below, so that the towing vehicle can then be moved independently of the trailer. After the emergency uncoupling, the first drawbar section 1 remains connected to the towing vehicle and the second drawbar section 2 remains connected to the trailer, but there is no longer any connection between the two drawbar sections 1 and 2. This emergency uncoupling function is described below with regard to the... Fig. 2 and Fig. 3 explained in more detail.

[0068] As shown in the depiction of the Fig. As can be seen in Figure 2, the first drawbar link 1, on the towing vehicle side, or rather its connection area, has a substantially tubular cross-section, and the second drawbar link 2, on the trailer side, or rather its connection area, is inserted axially into the first drawbar link 1. The cross-sectional shape of the second drawbar link 2 is described below with regard to the Fig. 1 will be explained in more detail.

[0069] Initially, the two drawbar sections 1 are movable relative to each other in the axial direction, i.e., along the longitudinal axis L. The longitudinal axis L corresponds to the central axis of the two drawbar sections 1, 2, and this extends parallel to the ground in the direction of travel. To then connect the two drawbar sections 1, 2, the connecting element 3, designed as a bolt, is inserted from below through the two drawbar sections 1, 2, thus positively connecting them via the connecting element 3.

[0070] To allow the connecting element 3 to be inserted accordingly, both drawbar sections 1, 2 each have a receptacle 1.1, 2.1 designed as a bore. When the two drawbar sections 1, 2 are inserted into one another, the two receptacles 1.2, 2.1 can be aligned so that, in the assembled state, a recess extending through both drawbar sections 1, 2 is formed. This recess is also, for example, in the Fig. 3 clearly visible. When the connecting element 3 is now inserted into this recess 3.2, the two drawbar sections 1, 2 are reliably connected to each other via the connecting element 3.

[0071] In order to separate the two drawbar sections 1, 2 from each other in an emergency situation, the connecting element 3 must again be removed from the receptacles 1.1, 1.2 and from the one in the Fig. 2 shown connection position V into the one in the Fig. The release position F shown in section 3 will be transferred.

[0072] The connecting element 3, which connects the two drawbar sections 1, 2, is pre-tensioned by a spring 5 in the direction of the release position F. The spring 5, designed as a helical spring, is arranged between a radially projecting shoulder 3.1 of the connecting element 3 and the outer surface of the first drawbar section 1. In the illustration according to Fig. 2 The spring force acts perpendicular to the longitudinal axis downwards and this force wants to drive the connecting element 3 out of the receptacles 1.1, 2.1.

[0073] At the end of the connecting element 3 opposite the spring 5, it is secured in the connected position V by a locking device 4, so that the preload force does not cause the connecting element 3 to move. For the connecting element 3 to be automatically moved into the release position by the spring 5, the locking device 4 securing the connecting element 3 must first be actuated or unlocked.

[0074] The locking device 4 essentially consists of two elements: a wedge-shaped locking element 4.1 and a pressure cylinder 4.2, which is connected to the locking element 4.1 via a rod. In the illustration according to Fig. 2. The locking device 4 is in a locking position S, i.e., the locking element 4.1 secures the connecting element 3 against movement into the release position F. This represents normal driving operation in which the trailer is coupled to the towing vehicle.

[0075] The locking element 4.1 has a plate-like geometry and, in the locking position S, engages in a slot-shaped recess 3.2 of the connecting element 3, or rather, the locking element 4.1 penetrates the upper part of the connecting element 3 and thus prevents it from moving. A positive-locking connection also exists between the locking element 4.1 and the connecting element 3 in the locking position S.

[0076] In order for the connecting element 3 to be driven by the spring 5 and move into the release position F to separate the two drawbar sections 1 and 2, the locking element 4.1 must first be pulled out of the recess 3.2 of the connecting element 3, thereby releasing the locking mechanism of the connecting element 3. To move the locking element 4.1 accordingly, the pressure cylinder 4.2 is pressurized with compressed air, which then pulls the locking element 4.1 from the locked position S against the force of a spring into the unlocked position E. The locking element 4.1 slides down the outside of the first drawbar section 1 until it reaches the position shown in the illustration. Fig. The unlocking position E shown in section 3 has been reached.

[0077] To initiate the corresponding movement, the pressure cylinder 4.2 is connected to a vehicle-side pressure network via a corresponding interface and can be supplied with compressed air from inside the towing vehicle via a remote control if required.

[0078] As soon as the locking element 4.1 is pulled out of the recess 3.2 of the connecting element 3, it is no longer secured. The spring force of the spring 5 can then develop, and the connecting element 3 is essentially forced downwards out of the two receptacles 1.1, 2.1 and accelerated towards the release position F. Once the spring 5 has driven the connecting element 3 out of the receptacles 1.1, 2.1 of the two drawbar sections 1, 2, the two drawbar sections 1, 2 are axially movable relative to each other, and the force transmission between the towing vehicle and the trailer is interrupted. The towing drawbar 10 is then separated into two parts, and the trailer is emergency-disconnected from the towing vehicle, so that the towing vehicle can be moved independently of the trailer.

[0079] The spring 5, which pre-tensions the connecting element 3, is already pre-tensioned when the two drawbar links 1, 2 are connected, or when the connecting element 3 is inserted into the two receptacles 1.1, 2.1. The force required to release the two drawbar links 1, 2, which moves the connecting element 3 into the release position P, is thus available from the outset and only needs to be released for emergency uncoupling of the trailer. The force required to move the locking element from the locked position S to the unlocked position E is significantly less than the pre-tension force exerted by the spring 5 on the connecting element 3, so that essentially only a small impulse is sufficient to achieve reliable emergency uncoupling. This is further supported by the wedge-shaped design of the locking element 4.1, as its wedge shape allows the locking element 4.1 to be removed from the recess 3 with minimal force.2 of the connecting element 3 can be pulled.

[0080] With regard to the presentation of the Fig. 1. The cross-section of the second drawbar link 2, e.g., the connection area of ​​the second drawbar link 2 that can be connected to the first drawbar link 1, will now be explained in more detail. The outer diameter of the second drawbar link 2 corresponds approximately to the free inner diameter of the first drawbar link 1, so that the two drawbar links 1, 2 can only move slightly in the radial direction relative to each other after being inserted into one another.

[0081] Furthermore, the receptacle 2.1 of the second drawbar link 2 is designed such that, even after being connected to the first drawbar link 1 by the connecting element 3, the second drawbar link 2 can rotate relative to the first drawbar link 1 within certain limits. Therefore, lateral tipping movements of the trailer, which are to be expected, for example, on uneven terrain or a slope, are not directly transmitted to the vehicle. Instead, the trailer can rotate back and forth around its longitudinal axis L within certain limits, together with the drawbar link 2 on the trailer side. This mobility reduces torsional forces, or rather, these forces are only transmitted to the vehicle above a certain angle of rotation.

[0082] To allow for a corresponding relative rotation of the two drawbar sections 1, 2, the second drawbar section 2 has two opposing tapers 2.2 in the area of ​​the receptacle 2.1, relative to a horizontal plane parallel to the ground. These tapers 2.2 are in the form of a pointed notch extending to the center of the drawbar section 2. The flanks 2.3 of the tapers 2.2 are straight and form an angle of approximately 15 degrees to the vertical central axis of the connecting element 3. The two flanks 2.3 of a taper 2.2 therefore form an angle of approximately 30 degrees to each other. The corresponding angular range W is also shown in the illustration of the Fig. 1 shown.

[0083] The flanks 2.3 of the opposing tapers 2.2, which converge in the area of ​​a horizontal and centrally arranged transverse axis, form an angle of approximately 150 degrees at the point of contact. Furthermore, the flanks 2.3 act as stops that limit the rotational movement of the two drawbar sections 1, 2 relative to each other. This is shown by the Fig. As can be seen in Figure 1, the two drawbar links 1, 2 can only be rotated relative to each other until the flanks 2.3 come into contact with the connecting element 3 and further rotation is prevented.

[0084] Another aspect of the towing drawbar 10 is explained by the Fig. Figure 4 shows the towing drawbar 10 in a top view, whereby the middle part of the towing drawbar 10, in which the two drawbar sections 1, 2 are connected, is not shown. As can be seen in the illustration of the Fig.As can be seen in Figure 4, the second drawbar link 2 has a drawbar 2.5 by which it is connected to the trailer. The drawbar 2.5, in turn, essentially consists of two drawbar arms 2.6, which are connected to the trailer on one side and have interlocking toothed segments 2.7 on the other side. Because of the toothed segments 2.7, it is not possible to move the two drawbar arms 2.6 independently of each other, even when they are detached from the trailer. Instead, a movement of one drawbar arm 2.6 inevitably leads to an opposing movement of the other drawbar arm 2.6. For example, if the right drawbar arm 2.6 is moved towards the center of the left drawbar arm 2.6, the left drawbar arm 2.6 automatically moves in the opposite direction towards the right drawbar arm 2.6 until both drawbar arms 2.6 meet in the middle. Via the interlocking connection of the two pull legs 2.Forces and torques can be transmitted between the two drawbars 2.6. Furthermore, the drawbar fork 2.5 ensures that forces are distributed as evenly as possible between both drawbars 2.6 and transmitted along the angle bisectors of the drawbars 2.6.

[0085] In the area of ​​the tooth segments 2.7, both drawbar arms 2.6 are rotatably mounted in a common retaining element 2.8, which essentially consists of two parallel plates, one plate being located above the tooth segments 2.7 and the other plate below them. Forces can thus be transmitted via the retaining element 2.8 between the drawbar arms 2.6 on one side and the connection area of ​​the drawbar link 2 for connection with the first drawbar link 1 on the other side. Reference symbol: 1 drawbar link 1.1 Recording 1.2 Towing eye 2 Drawbar link 2.1 Recording 2.2 Rejuvenation 2.3 Flank 2.5 Drawbar 2.6 Pull leg 2.7 Tooth segment 2.8 Retaining element 3 Connecting element 3.1 Head 3.2 Exclusion 4 Safety device 4.1 Safety element 4.2 Pressure cylinder 5 springs 10 Towing drawbar F Release position V connection position S safety position E unlocking position L Longitudinal axis W angle range

Claims

[1] Towing drawbar, via which a trailer can be coupled to a towing vehicle so that the trailer can be towed by the towing vehicle, with two drawbar links (1, 2), wherein one of the drawbar links (2) can be connected to the trailer and the other drawbar link (1) to the towing vehicle, wherein a connecting element (3) is provided which connects the two drawbar links (1, 2) to each other in a connection position (V) and which is secured in the connection position (V) by a locking device (4), wherein the connecting element (3) is biased by a spring (5) into a release position (F) which releases the connection of the two drawbar links (1, 2), and wherein the locking of the connecting element (3) can be released by actuating the locking device (4), so that the connecting element (3) is automatically moved into the release position (F) for emergency uncoupling of the trailer from the towing vehicle due to the bias,characterized by , that at least one drawbar link (1, 2) is arranged between the spring (5) and the locking device (4). [2] Towing drawbar according to claim 1, characterized by , that the connecting element (3) extends in the vertical direction in the connection position (V). [3] Towing drawbar according to one of claims 1 or 2, characterized by , that the spring (5) engages in one end region of the connecting element (3) and the locking device (4) in the opposite end region of the connecting element (3). [4] Towing drawbar according to any of the preceding claims, characterized by , that the two drawbar sections (1, 2) can be inserted into each other. [5] Towing drawbar according to any of the preceding claims, characterized by, that the two drawbar sections (1, 2) each have a receptacle (1.1, 2.1) for receiving the connecting element (3), wherein the receptacles (1.1, 2.1) can be brought into alignment when the drawbar sections (1, 2) are inserted into each other, so that the connecting element (3) can engage through the two receptacles (1.1, 2.1) in the connection position (V). [6] Towing drawbar according to any of the preceding claims, characterized by , that the two interconnected drawbar links (1, 2) are designed to be rotatable relative to each other within a predetermined angular range (W) about a longitudinal axis (L). [7] Towing drawbar according to claim 6, characterized by, that one of the drawbar links (1, 2) has two opposing tapers (2.2) to enable relative rotation, wherein each taper (2.2) has two flanks (2.3) arranged at an angle to each other and wherein the flanks (2.3) are designed as stops that limit relative rotation of the two drawbar links (1, 2). [8] Towing drawbar according to any of the preceding claims, characterized by , that the locking device (4) has a locking element (4.1) that can be moved back and forth in a locking direction (S) between a locking position (S) and an unlocking position (E), wherein the locking element (4.1) in the locking position (S) blocks a movement of the connecting element (3) into the release position (F). [9] Towing drawbar according to any of the preceding claims, characterized by, that the force required to unlock the locking device (4) is less than the preload force acting on the connecting element (3). [10] Towing drawbar according to any of the preceding claims, characterized by , that the connecting element (3) has a recess (3.2), in particular a slot-shaped one, in which the locking element (4.1) is arranged in the locking position (S), wherein the locking element (4.1) can be pulled out of the recess (3.2) to unlock the connecting element (3). [11] Towing drawbar according to any of the preceding claims, characterized by , that the locking element (4.1) can be moved, in particular pressed, into the unlocked position (E) via a pressure cylinder (4.2), wherein the pressure cylinder (4.2) is designed to be remotely controllable for emergency decoupling. [12] Towing drawbar according to any of the preceding claims, characterized by, that one of the drawbar links (1, 2) has a drawbar (2.5) via which it can be connected to the trailer, wherein the drawbar (2.5) has two drawbar arms (2.6) which each have a toothed segment (2.7) at one end, via which the two drawbar arms (2.6) are connected to each other in a movement-coupled manner. [13] Towing drawbar according to claim 12, characterized by , that the drawbars (2.6) can be connected to the trailer at the ends opposite the tooth segments (2.7). [14] Trailer for a towing vehicle with a towing drawbar (10) according to one of the preceding claims. [15] Vehicle combination comprising a towing vehicle and a trailer, wherein the trailer is detachably coupled to the towing vehicle via a towing drawbar (10) and wherein the towing drawbar (10) is designed according to one of claims 1 to 13.

Images