Tow truck with a horizontally adjustable towing device

Abstract

The invention relates to a tow truck 100, which has a vehicle frame 10, a platform superstructure 11, and a towing device 20 mounted below the platform superstructure 11. The towing device 20 comprises a boom 12, wherein the boom 12 has a support 13 which is coupled to the vehicle frame 10 via a first joint 14 with a first axis of rotation 15 and is pivotable about the axis of rotation 15 by means of a first cylinder assembly 16. State-of-the-art towing vehicles 100' with a platform body 11 and a towing device are generally used for recovering and towing passenger cars 300. On such towing vehicles 100', the boom 12' can only pivot about a single axis 15'. Therefore, the boom 12' can only assume a horizontal position in one pivot position. Trucks increasingly have special mountings in their front area for screwing in tow hooks 39. In order to tow a truck 200 using the tow hook 39, the towing device 20 must be horizontally aligned. In order to enable a tow truck 100, which has a platform superstructure 11 and a towing device 20, to be used for towing both cars and trucks, it is proposed that a second joint 21 be integrated into the support 13 of the boom 12. The second joint 21 includes a second axis of rotation 22. By means of a second cylinder assembly 23, the boom 12 can be pivoted about the second axis of rotation 22 and thus horizontally aligned in different height positions.

Description

[0001] The invention relates to a tow truck comprising a vehicle frame, a platform superstructure, and a towing device mounted below the platform superstructure. The towing device includes a boom, the boom having a support which is coupled to the vehicle frame via a first joint with a first axis of rotation and is pivotable about the first axis of rotation by means of a first cylinder assembly.

[0002] In the Fig. 7, Fig. 8 to Fig. Figure 9 schematically depicts a towing vehicle 100' representing the state of the art, equipped with a towing device 20'. Such a towing device 20' is typically used for recovering and towing passenger vehicles (cars) 300. The towing device 20' comprises an extendable boom 12' and a swiveling frame in which two front wheels or two rear wheels of a vehicle to be towed can be accommodated. Such a frame is generally referred to as a "spectacle." The swiveling frame thus forms the "spectacle" 35'. The "spectacle" 35' is attached to a crossbeam 29' and coupled to the boom 12' by means of a joint 36' (central bolt).

[0003] To tow a motor vehicle, the towing frame 35' must first be positioned under the front or rear wheels of the car 300 being towed. For this purpose, the boom 12' is first lowered with a cylinder assembly 16', and the tow vehicle 100' is driven towards the vehicle to be towed with the towing frame 35' lowered close to the ground (see figure). Fig. 8) After the front or rear wheels of the vehicle to be towed have been received and secured in the frame 35', the boom 12' is raised by means of the cylinder assembly 16'. The front or rear wheels received in the frame 35 lose contact with the ground and the vehicle 300 to be towed can be towed (see Figure 8). Fig. 9).

[0004] Heavy-duty, truck-based recovery vehicles are generally used for towing trucks and buses. These recovery vehicles typically feature a tow bar with a high load capacity, specifically designed for towing heavy vehicles. The technology and operation of these truck tow bars are similar to the tow bars for passenger cars described above. Such state-of-the-art truck recovery vehicles do not have a platform body. Instead, the tow bar and the associated hydraulic lifting device are integrated directly into the body of the towing truck. These truck tow bars have a high lifting capacity and can generally be rotated around a pivot axis as well as lifted vertically in a lifting frame. Trucks to be towed can thus be secured in the tow bar and lifted using the lifting device.

[0005] Newer trucks and buses increasingly feature additional, defined mounting points for tow hooks on the front, above the bumpers. One end of the tow hook screws into these mounting points on the vehicle, while the other end hooks onto a corresponding tow hitch. Once the tow hooks have been attached to the recovery vehicle, the towed vehicle can be lifted using the lifting mechanism, thus relieving the front axle of the vehicle being towed. However, this relief is only partial. The wheels remain in contact with the ground and, with the steering lock released, continue to follow the tow vehicle during the towing process.This type of hitch has the particular advantage that the tow bar does not need to be placed under the front wheels, thus reducing the risk of damage to the front of the vehicle being towed. Furthermore, the overall height of the vehicle being towed remains unchanged.

[0006] To tow a truck with its front wheels in contact with the ground using the tow hooks, the towing device must be leveled. This leveling is particularly important when cornering, as it prevents the towed vehicle from oscillating around a central axis pointing in the direction of travel. Such oscillations would result in uneven load distribution and / or varying distances between the tow hooks and the ground, or uneven load distribution on the two front wheels. To avoid these uneven load distributions, the towing device, positioned between the recovery vehicle and the vehicle being towed, is leveled using the lifting mechanism on the recovery vehicle before towing begins.

[0007] Since the car tow truck, known as state of the art, is 100' according to the Fig. 7, Fig. 8 to Fig. 9 does not have a lifting frame with lifting device and the towing device 20' can only be pivoted about a pivot axis 15', it is not suitable for towing trucks or buses on the aforementioned hooks.

[0008] The installation space available for mounting the towing device 20' is located below the platform superstructure 11 and thus close to the ground. The mounting of the towing device 20' to the tow truck 100' is designed so that a low approach angle results when the tow bar 35' is lowered to the road surface. This is necessary to be able to pick up even cars 300 that have low ground clearance and / or are lowered.

[0009] As a result, on tow trucks with a platform body and towing device, which are considered state of the art, the boom, when extended in the towing position, is not in the horizontal position required for the use of truck towing adapters, but rather at an angle. As explained above, this angled boom position causes problems during towing, especially when cornering.

[0010] The object of the invention is to eliminate the described disadvantages and to propose a tow truck with a platform body and towing device, with which both cars and heavy motor vehicles such as trucks or buses can be towed.

[0011] Another object of the invention is to propose a towing device that can be attached to towing vehicles and that enables the towing of heavy motor vehicles.

[0012] The problem is solved by a tow truck with the features of claim 1. Explanation of claim 1

[0013] The towing vehicle according to the invention comprises a vehicle frame, a platform superstructure, and a towing device with a boom mounted below the platform superstructure. The boom is preferably telescopic and, in this case, has an outer segment and one or more inner segments arranged therein. The telescoping is preferably achieved by means of a retractable hydraulic cylinder arranged inside the boom. A crossbeam with two foldable and removable mounts for the wheels of a vehicle to be towed is attached to the rearward-facing end of the boom (as viewed in the direction of travel). The boom also has a support which is coupled to the vehicle frame via a first joint with a first axis of rotation and can be pivoted about the axis of rotation by means of a first cylinder assembly.

[0014] According to the invention, the support further comprises a second joint with a second axis of rotation and the boom is pivotable about the second axis of rotation by means of a second cylinder device.

[0015] The boom can thus be pivoted around two axes. This makes it possible to first pivot the boom upwards or downwards around the first axis using the first cylinder assembly, and then, in a second step, to align it horizontally using the second cylinder assembly. Put simply, the boom can be moved into the desired position for each application within the range of extension movements predefined by the cylinder assembly. Within a range predefined by the cylinder assembly, for example, from the road surface up to a height of one meter, the boom can be continuously aligned horizontally at any desired height. This continuous horizontal adjustment is also advantageous because the height at which the hooks can be attached to the trucks or buses depends on the specific vehicle type and wheel size.It is therefore important to be able to align the towing device horizontally not only at a single height, but at the height predefined by the mounting height of the towing hooks.

[0016] The second cylinder assembly, by means of which horizontal alignment is achieved, is preferably designed so that it does not impair the maximum lifting height of the first cylinder assembly. This is particularly important if the first cylinder assembly is designed not only for raising and lowering the boom for towing a vehicle, but also for raising the boom into a near-vertical recovery position. A vertical recovery position is understood to be a position of the boom in which a traction element coupled to a winch, for example a steel cable, is connected to a vehicle to be recovered via the boom end, which is located at a relatively high height.From a winch mounted at the front of the tow truck, the cable runs diagonally upwards to the end of the boom or to a pulley system attached there, and then diagonally downwards via a deflection point to the vehicle to be recovered. As the steel cable is pulled in, the attached vehicle is thus initially pulled diagonally upwards. This facilitates the recovery process or, in extreme cases, makes it possible in the first place. Explanation of claim 2

[0017] The first and second cylinder units can each comprise a single hydraulic cylinder. However, it is also possible for one cylinder unit, particularly the first cylinder unit, to have two hydraulic cylinders operating in parallel. The two hydraulic cylinders are preferably mounted symmetrically to a central axis of the tow vehicle aligned with the direction of travel. The second cylinder unit essentially serves to align the boom horizontally and is preferably mounted in the center of the towing device between the two hydraulic cylinders of the first cylinder unit. Such a mounting of the first and second cylinder units minimizes any stresses, for example those caused by lateral forces, during cylinder actuation. Explanation of claim 1 3

[0018] As explained above, the boom of the towing device can be telescopic. In this case, it has not only an outer segment but also one or more inner segments. The second cylinder assembly is preferably coupled to the support and the outer segment. Since the support itself is pivotably mounted on the boom, preferably on its outer segment, at one end and forms a bearing for the second cylinder assembly at the other end, the angle between the support and the outer segment can be varied as desired within the stroke range predefined by the second cylinder assembly. Explanation of claim 4

[0019] Preferably, the boom of the towing device includes a bearing plate with a receptacle for the second joint of the support. Such a bearing plate facilitates the assembly and disassembly of the cylinder assembly and transmits the force or torque applied when the second cylinder assembly is actuated evenly to the boom. Explanation of claim 5

[0020] The aforementioned bearing plate can be made in two parts, whereby - a first part is firmly connected to the boom and has the receptacle for the second joint and - a second part is detachably connected to the first part and includes a mount for the first joint.

[0021] With the first and second parts assembled and the support removed, the second axis of rotation is eliminated, and the boom can only pivot about the first axis. In simplified terms, this design functionally corresponds to the state-of-the-art rigid mounting of a boom that pivots only about one axis, as described in [reference to relevant standard / document]. Fig. 7, Fig. 8 to Fig. 9. The difference lies in the fact that the bearing plate is a single piece there, whereas in the embodiment according to the invention two parts are provided which are fixedly mounted.

[0022] With the second section removed and the support mounted, the boom can pivot around both axes. This simplifies the retrofitting of the boom from the "pivotable around one axis" version to the "pivotable around two axes" version.

[0023] Retrofitting is also possible by replacing an entire outer segment of the boom. In this type of retrofit, an outer segment of a boom known to be state-of-the-art is replaced according to the... Fig. 7, Fig. 8 to Fig. 9 is replaced by an outer segment with a support that pivots about two axes of rotation. A particular advantage of the invention is therefore also that the first cylinder assembly, the first axis of rotation and the first pivot joint are not affected by the attachment of a support according to the invention with a second axis of rotation, a second pivot joint and a second cylinder assembly. Explanation of claim 6

[0024] To enable quick and easy conversion of the tow truck from the "towing with tow bar" function to the "towing with truck towing adapters" function, the towing device's boom preferably includes a crossmember with coupling points for the detachable attachment of towing adapters. For example, the towing adapter may be designed so that, in the coupling area, it corresponds to the tow bar's mounting point, but instead of the frame, it has a drawbar or towing eye compatible with the tow hook on the vehicle being towed. Preferably, the two elements to be coupled may have a locking mechanism to prevent the coupling from becoming detached during towing, such as a hook popping out of the attachment due to uneven road surfaces. The locking device may be, for example, a locking pin or a spring-loaded latch. Explanation of claim 7

[0025] In a preferred embodiment, the first and second cylinder assemblies are controlled via a hydraulic valve, preferably a directional control valve. A directional control valve allows the flow rate to be distributed between the two cylinder assemblies particularly easily and reliably.

[0026] The directional control valve can be configured, for example, as a 6 / 3-way valve with a center position or as a 6 / 2-way valve without a center position. In the 6 / 2-way valve without a center position, the main consumer is controlled when the valve is in the unswitched state. When switched, another consumer is operated. The switching is achieved hydraulically or electrically. In the electrical version, the control pressure required for the switching process is taken from the high-pressure supply line, so no additional pilot pressure is required. In the 6 / 3-way valve version, the center position is reached when both inlet lines are depressurized. In this position, all inlets and outlets are mutually closed.

[0027] By integrating a 6 / 2 or 6 / 3-way valve, it can be ensured that both cylinder units are not actuated simultaneously, thereby preventing incorrect operation and / or damage. Explanation of claim 8

[0028] In another embodiment, an automatic control system can be provided to actuate the first and second cylinder units. For example, it can be provided that, with the towed vehicle coupled, the first cylinder unit first raises the boom until the front axle of the towed vehicle is relieved of a predefined load, and then the second cylinder unit automatically adjusts the boom – preferably using suitable sensors – into a horizontal position. Other control loops or functional sequences can also be implemented using the automatic control system. Explanation of claim 1 9

[0029] The problem according to the invention is also solved by a towing device for a towing vehicle, wherein the towing device comprises a boom with a support which, together with the boom, is pivotable about a first axis of rotation and is coupled to the boom by means of a second axis of rotation.

[0030] Such a towing device forms a component assembly that can be provided, for example, as a retrofit kit for a tow truck and installed there.

[0031] Further measures improving the invention are described in more detail below with reference to the figures and preferred embodiments of the invention.

[0032] The figures show: Fig. Figure 1 shows the rear of a towing vehicle according to the invention with a partially extended boom and the front area of ​​a truck that is not yet coupled; Fig. 2 shows the tow truck according to Fig. 1 with attached truck; Fig. Figure 3 shows the isolated towing device of the towing vehicle according to Fig. 1 with glasses folded in; Fig. Figure 4 shows the isolated towing device of the tow truck according to Fig. 1 with attached towing adapters; Fig. Figure 5 shows the isolated towing device of the tow truck according to Fig. 2 with attached towing adapters; Fig. Figure 6 shows the tow truck according to Fig. 1 with boom extended into a recovery position; Fig. Figure 7 shows a tow truck with a towing device known as state of the art and in a rest position; Fig. Figure 8 shows the tow truck according to Fig. 7 with tow bar lowered onto the road surface; Fig. Figure 9 shows the tow truck according to Fig. 7 with a car picked up in the towing goggles.

[0033] Identical or similar elements in the following figures may be designated with the same or similar reference numerals. Furthermore, the figures of the drawing, their description, and the claims contain numerous features in combination. It is clear to a person skilled in the art that these features can also be considered individually or combined into further combinations not described in detail here. The invention expressly extends to embodiments that are not defined by combinations of features from explicit cross-references in the claims, meaning that the disclosed features of the invention can be combined with one another in any way that is technically feasible. The exemplary embodiments shown in the figures are therefore merely descriptive and are not intended to limit the invention in any way.

[0034] The terms used below, “upper”, “top”, “lower”, “left” or “right”, refer to the arrangement of the components of a tow truck or towing device in operating mode as shown in the drawing.

[0035] The Fig. 1 and Fig. Figure 2 shows the rear of a towing vehicle 100 according to the invention, comprising a vehicle frame 10 and a platform superstructure 11 mounted thereon. A towing device 20 is mounted below the platform superstructure 11. In the illustrated embodiment, the towing device 20 comprises a hydraulically extendable boom 12 with an outer segment 18 and several inner segments 19. The boom 12 has a receptacle 28 for a first joint 14 and is pivotably coupled to the vehicle frame 10 about a first axis of rotation 15 by means of a first cylinder assembly 16. In the illustrated embodiment, the first cylinder assembly 16 comprises two hydraulic cylinders 17, which, in the assembled state of the towing device 20, are arranged symmetrically to the vehicle's central axis 37.When the cylinder assembly 16 is actuated, the two hydraulic cylinders 17 brace themselves against the vehicle frame 10 at coupling points 38 and pivot the boom 12 upwards or downwards about the first axis of rotation 15.

[0036] In contrast to the towing devices 20' known as state of the art with a one-piece bearing plate 25' fixed immovably to the boom 12' (cf. Fig. 7, Fig. 8 to Fig. 9) The boom 12 is pivotable not only about the first axis of rotation 15, but also about a second axis of rotation 22. This pivotability is achieved by providing a bearing plate 25 with a receptacle 26 for a support 13 on the boom 12 of the towing device 20 according to the invention. The receptacle 26, in combination with the support 13, forms a second joint 21 with a second axis of rotation 22. The support 13 is coupled at its other end to the vehicle frame 10 via the receptacle 28 and the first joint 14 and is pivotable about the first axis of rotation 15. Alternatively, it is also possible for the support 13 to be coupled to a bearing block (not shown) and for the pivoting movement of the support 13 to occur not directly about the first axis of rotation 15, but about an axis of rotation formed by the bearing block.

[0037] The support 13 is thus coupled directly or indirectly to the vehicle frame 10 at one end. At its other end, it is coupled directly or indirectly to the boom 12. In the illustrated embodiment, the coupling to the boom 12 is achieved by the bearing plate 25 and the receptacle 26 contained therein. The receptacle 26, in combination with the support 13, forms the second joint 21 with the second axis of rotation 22, about which the boom 12 can pivot relative to the vehicle frame 10 via the support 13.

[0038] Regardless of how the pivot axes of the support 13 are designed and arranged, the boom 12 can thus be pivoted not just about a single axis, but about at least two axes 15, 22. The advantage of this dual pivotability is that when pivoting the boom 12, there is not just one way to bring it into a horizontal position, but infinitely variable possibilities. Since the boom 12 can be pivoted independently about the two axes 15, 22, any tilting of the boom 12 resulting from a first pivot about one axis 15 can be compensated for by a counter-rotating pivot about the other axis, thus aligning the boom 12 horizontally. In simplified terms, the boom 12 can be moved up and down parallel to the roadway.

[0039] How Fig. Figure 1 further shows the tow truck 100 positioned in front of a truck 200 to be towed. The boom 12 is partially extended and in a horizontal position. A towing adapter 31 attached to the boom 12 is located below the towing hooks 39 attached to the truck. The towing hooks 39 are special components designed for towing and can be screwed into factory-installed receptacles in the front of the truck 200.

[0040] To couple the towing adapters 31 to the hooks 39, the boom 12 – and thus also the position of the towing adapters 31 – can be moved by an operator using a control system (not shown). With the tow truck 100 stationary, the operator extends the boom 12 a little further towards the truck 200 and, once the desired position is reached, swings it upwards until the hooks 39 are engaged and / or locked into the towing adapter 31 (see figure). Fig. 2) Subsequently, the front axle of the truck 200 to be towed is relieved of its load by further pivoting the boom 12 upwards, and the boom 12 is aligned horizontally by means of the two cylinder assemblies 16, 23. The two cylinder assemblies 16, 23 are actuated via a hydraulic valve 32, which in the illustrated embodiment is a 6 / 2-way valve 33. The truck 200, coupled to the tow vehicle 100, is now ready for towing. With the steering lock released, the wheels of the truck 200, now unloaded but in contact with the road surface, follow the track of the preceding tow vehicle 100.

[0041] The Fig. 3, Fig. 4 to Fig. Figure 5 shows the freestanding towing device 20 of the towing vehicle 100 in detail. Fig. Figure 3 shows the towing device 20 with two detachable frames 40, which are mounted on coupling points 30 of a crossbeam 29 attached to the end of the boom 12. The two frames 40 together form a frame 35. The coupling point 30 is formed by a square tube of the crossbeam 29 in conjunction with a square tube of the frame 40 that can be attached to the square tube of the crossbeam 29.

[0042] Fig. Figure 4 shows the towing device 20 after disassembly of the frame 35 and assembly of the towing adapters 31. Analogous to the frames 40 of the frame 35, the towing adapters 31 have a square tube that can be mounted onto the crossbeam 29. The towing adapters 31 also serve as support brackets for a shaft 41, which can be used to engage and lift the towing hooks 39. In the illustration according to Fig. 4. The hydraulic cylinders 17 and 24 are retracted. The towing device 20 is therefore in the position shown in Fig. Position 1 shown.

[0043] Fig. Figure 5 shows the towing device 20 with cylinders 17 and 24 extended. The towing device 20 is thus in the position shown in Fig. 2. Position shown. The isolated illustration of the catch hooks 39 clarifies how the catch hooks 39 can be engaged by means of the shafts 41.

[0044] In the Fig. 3, Fig. 4 to Fig. In the embodiment shown in Figure 5, the bearing plate 25 is depicted as an approximately trapezoidal first part 27 with a receptacle 26 for the second joint 21 and the coupling of the support 13. With an additional second part (not shown), the bearing plate 25 could be extended upwards to the first joint 14. Such a bearing plate formed from the first part 27 and a second part fixed to it would correspond to the bearing plate 25' according to Figure 5. Fig. 7, Fig. 8 to Fig. 9. A two-part bearing plate simplifies the conversion from the embodiment "jib pivotable about one axis of rotation" to the embodiment "jib pivotable about two axes of rotation".

[0045] Fig. Figure 6 shows the rear 34 of the tow truck 100 with the boom 12 extended into a recovery position. When the boom 12 is extended into the recovery position, the first cylinder assembly 16 is fully extended, while the second cylinder assembly 23 is retracted. To prevent a collision between the upward-swinging boom 12 and the platform superstructure 11, the platform superstructure 11 has a substantially U-shaped recess 44 in its rearward area (viewed in the direction of travel).

[0046] With the boom 12 swung upwards into the recovery position, damaged vehicles can be coupled to a recovery cable 42 at an angle favorable for recovery. The recovery cable 42, coupled to the vehicle to be recovered, is guided via a deflection 43 to a winch (not shown). When the recovery cable 42 is pulled in, the vehicle to be recovered is thus pulled diagonally upwards towards the crossbeam 29. Reference symbol list 10 vehicle frames 11 Plateau construction 12.12' boom 13 carriers (out of 12) 14, 14' first joint 15, 15' first axis of rotation 16, 16' first cylinder arrangement 17 cylinders (out of 16) 18, 18' Outer segment (of 12) 19, 19' Inner segment (of 12) 20, 20' Towing device 21 second joint 22 second axis of rotation 23 second cylinder assembly 24 cylinders (out of 23) 25 bearing plate 26 recordings (for 21) 27 first part (of 25) 28 recordings (for 14) 29 traverse 30 coupling points (at 29) 31 towing adapters 32 Hydraulic valve 33 6 / 2-way valve 34, 34' Rear 35, 35' glasses 36, 36' joint 37 Vehicle center axle 38 coupling points (out of 17) 39 Hooks 40 frames (out of 35) 41 wave 42 rescue rope 43 Deflection 44 recess (in 11) 100, 100' tow truck 200 trucks 300 cars

Claims

Towing vehicle (100) comprising a vehicle frame (10), a platform superstructure (11) and a towing device (20) with a boom (12) mounted below the platform superstructure (11), wherein the boom (12) comprises a support (13) which is coupled to the vehicle frame (10) via a first joint (14) with a first axis of rotation (15) and is pivotable about the axis of rotation (15) by means of a first cylinder assembly (16), characterized in that the support (13) has a second joint (21) with a second axis of rotation (22) and the boom (12) is pivotable about the second axis of rotation (22) by means of a second cylinder assembly (23). Towing vehicle (100) according to claim 1, characterized in that one or more hydraulic cylinders (17, 24) are provided as the first and second cylinder units (16, 23). Towing vehicle (100) according to one of the preceding claims, characterized in that the boom (12) of the towing device (20) is telescopic and comprises an outer segment (18) and the second cylinder assembly (23) is coupled with a first end to the support (13) and with a second end to the outer segment (18). Towing vehicle (100) according to one of the preceding claims, characterized in that the boom (12) of the towing device (20) comprises a bearing plate (25) with a receptacle (26) for the second joint (21). Towing vehicle (100) according to claim 4, characterized in that the bearing plate (25) is designed in two parts, wherein a first part (27) is fixedly connected to the boom (12) and has the receptacle (26) for the second joint (21) and a second part is detachably connected to the first part (27) and comprises a receptacle (28) for the first joint (14), so that when the first part (27) and second part are assembled and the support (13) is removed, the second axis of rotation (22) is eliminated and the boom (12) is only pivotable about the first axis of rotation (15) and when the second part is removed and the support (13) is assembled, the boom (12) is pivotable about both axes of rotation (15, 22). Towing vehicle (100) according to one of the preceding claims, characterized in that the boom (12) of the towing device (20) comprises a crossbeam (29) and the crossbeam (29) has coupling points (30) for the detachable attachment of towing adapters (31). Towing vehicle (100) according to one of the preceding claims, characterized in that the control of the first and second cylinder assembly (16, 23) is carried out via a hydraulic valve (32), preferably via a 6 / 2-way valve (33). Towing vehicle (100) according to one of the preceding claims, characterized in that an automatic control system is provided for controlling the first and the second cylinder assembly (16, 23). Towing device (20) for a towing vehicle (100) comprising a boom (12) with a support (13) which is pivotable together with the boom (12) about a first axis of rotation (15) and is coupled to the boom (12) by means of a second axis of rotation (22) and is pivotable relative to the boom (12).

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