A motorhome connection device with an auxiliary safety mechanism and its connection method

Abstract

The present invention discloses a RV connection device with an auxiliary safety mechanism and a connection method thereof, comprising a crossbeam, an auxiliary rod, a connecting piece, a positioning rod, a second connecting frame, a hydraulic cylinder, a steering module, an oil pump and a controller, wherein a connecting piece is provided on one side of the crossbeam, a second connecting frame is provided on one end of the connecting piece away from the crossbeam, a symmetrically distributed first connecting frame is welded on both sides of the lower surface of the crossbeam, positioning rods are rotatably installed on both sides of the outer wall of the connecting piece away from the crossbeam, an auxiliary rod is rotatably installed between the surfaces of the opposite side of the crossbeam and the positioning rod, and a hydraulic cylinder is provided inside the auxiliary rod; an oil pump is installed on the upper surface of the mounting plate, a controller is provided on one side of the oil pump, and the controller is connected to the steering module. The present invention adopts a positioning rod to increase the connection stability of the second connecting frame, and cooperates with the auxiliary rod to adapt to the direction of vehicle steering to avoid the problem of easy twisting of the connection point during the turning process.

Description

Technical Field

[0001] The present invention relates to the technical field of RV connectors, and in particular to an RV connection device with an auxiliary safety mechanism and a connection method thereof. Background Art

[0002] An RV is a vehicle equipped with home functional devices, which is divided into two types: integrated and towed. The towed RV is connected by a connector between the towing vehicle and the towed RV. During the vehicle driving process, the connector bears the traction force of the towing vehicle and the pulling force of the towed carriage. Therefore, the stability of the connector is particularly important.

[0003] After a large amount of retrieval, it is found that the prior art, with the publication number: CN105422552A, discloses an RV connector. The connector includes two components with completely identical mirror-symmetric structures, namely the left component and the right component. The right component is an integrated structure, including a left working piece, a lower working piece, and a rear working piece. The left working piece is in the shape of a right trapezoid placed sideways with the rear end face area smaller than the front end face area. There is a vertically penetrating groove on the side facing the lower working piece and near the left end face of the rear working piece. The lower working piece is in the shape of a cuboid, and the rear working piece is a three-dimensional object with a right triangle with an arc hypotenuse in the longitudinal sectional view and a rectangle in the cross-sectional view. The structure of the present invention is simple and the fixing effect is good.

[0004] In summary, during the use of the existing RV connectors, due to the need to ensure the rotational flexibility between the towing vehicle and the towed RV, the connector needs to be set as a rotatable type. Therefore, the rotational structure of the connector is relatively weak. During the vehicle steering process, if the speed is too fast, the rear towed carriage will tilt. When the tilt angle is too large, it will cause mechanical torsion at the rotational position of the connector, resulting in deformation of the connector and inability to continue use, and at the same time, the steering stability cannot be guaranteed. Summary of the Invention

[0005] The purpose of the present invention is to provide an RV connection device with an auxiliary safety mechanism and a connection method thereof to solve the problems raised in the above background art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a motorhome connection device with an auxiliary safety mechanism and a connection method thereof, comprising a crossbeam, an auxiliary rod, a connecting piece, a positioning rod, a second connecting frame, a hydraulic cylinder, a steering module, an oil pump and a controller, a connecting piece is provided on one side of the crossbeam, a second connecting frame is provided on one end of the connecting piece away from the crossbeam, first connecting frames symmetrically distributed are welded on both sides of the lower surface of the crossbeam, positioning rods are rotatably installed on both sides of the outer walls of the ends of the connecting piece away from the crossbeam, first positioning blocks are welded on the surfaces of the opposite sides of the crossbeam and the positioning rods, an auxiliary rod is rotatably installed between the first positioning blocks, and hydraulic cylinders are provided inside the auxiliary rods;

[0007] A mounting plate is welded on the lower surface of the cross beam, an oil pump is mounted on the upper surface of the mounting plate, a controller is arranged on one side of the oil pump, and the controller is connected to the steering module.

[0008] Preferably, the crossbeam is rotatably connected to the connecting member, and a first latch is inserted into the rotatable connection;

[0009] One side of the second connecting frame is plugged into the connecting piece, and symmetrically distributed second latches are plugged between the second connecting frame and the connecting piece;

[0010] Bolts are rotatably inserted at the lower ends of the first latch and the second latch for positioning the first latch and the second latch.

[0011] Preferably, the first connecting frame is connected to the traction beam at the rear end of the vehicle, and the second connecting frame is connected to the traction beam of the trailer;

[0012] The first connecting frame is located at a height lower than that of the crossbeam and the second connecting frame.

[0013] Preferably, the positioning rods are in contact with the surface of the second connecting frame, and the outer walls at both ends of the positioning rods are symmetrically welded with second positioning blocks;

[0014] A U-shaped screw is inserted into the surface of the second positioning block, and the U-shaped screw is sleeved on the surface of the positioning rod and the second connecting frame to fix the positioning rod and the second connecting frame.

[0015] Preferably, the auxiliary rod is composed of a first position-limiting tube and a second position-limiting tube, and the first position-limiting tube is inserted into the upper end of the second position-limiting tube;

[0016] The hydraulic cylinder is located inside the second limiting tube, and a hydraulic rod connected to the inner wall of the top end of the first limiting tube is provided at the upper end of the hydraulic cylinder;

[0017] A shaft sleeve is arranged at the upper end of the second position limiting tube, and a linear bearing is embedded and installed inside the shaft sleeve to reduce the friction between the second position limiting tube and the first position limiting tube.

[0018] Preferably, an oil pipe penetrating the outer wall of the auxiliary rod is provided at the bottom end of the hydraulic cylinder, and the oil pump is connected to the oil pipe.

[0019] Preferably, the controller is connected to the oil pump, and the controller is connected to the steering module by a transmission line. The steering module is placed in the steering assembly and is used to detect the steering and transmit a signal to the controller for linkage of the two auxiliary rods to adapt the steering angle between the vehicle and the trailer.

[0020] A connection module is arranged on the side of the oil pump facing away from the controller, and interconnected connection nozzles are arranged on both sides of the connection module for connecting the brake pipe between the vehicle and the trailer.

[0021] Preferably, the connection method is as follows:

[0022] S1: Connecting the first connecting frame to the rear traction beam of the vehicle and the second connecting frame to the traction beam of the trailer respectively;

[0023] S2: Insert the second connecting frame into the connecting piece and fix it with the second latch, then fit the positioning rod to the surface of the second connecting frame, and sleeve the U-shaped screw on the positioning rod and the surface of the second connecting frame, and tighten the nut to stably connect the positioning rod to the second connecting frame;

[0024] S3: Connect the steering module to the controller via a transmission line, and adapt and connect the vehicle brake pipe to the trailer brake pipe via a connection module.

[0025] Preferably, in S2 of the connection method based on the RV connection device:

[0026] After the second connecting frame is stably connected to the connecting piece, the auxiliary rod is calibrated, the position between the vehicle and the trailer is adjusted to keep the vehicle and the trailer on the same axis, and the extension stroke of the hydraulic rod is adjusted synchronously.

[0027] Preferably, in S3 of the connection method based on the RV connection device:

[0028] During vehicle driving, the steering module can identify the turning direction and angle of the steering assembly. The steering module outputs a signal to the controller. The controller adjusts the forward and reverse rotation of the oil pump according to the output signal, and pumps out the hydraulic oil into the hydraulic cylinder corresponding to the reverse position of the steering. The hydraulic oil in the hydraulic cylinder at the position corresponding to the steering is pumped out through the negative pressure of the oil pump, thereby assisting the power steering between the trailer and the vehicle.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention stably connects the positioning rod with the second connecting frame, increasing the connection stability between the second connecting frame and the connecting piece. With the auxiliary rod providing lateral limitation between the positioning rod and the cross beam, the positioning rod and the cross beam can be kept on the same horizontal plane, improving the anti-torsion strength between the connecting piece, the cross beam, and the second connecting frame, avoiding the problem that when the vehicle turns at a too high speed, the trailer at the rear tilts and causes torsion to the connecting piece, and ensuring the service life of the connecting piece. Moreover, the hydraulic cylinder and oil pump system provided in the auxiliary rod can be adaptively adjusted according to the direction of vehicle steering, and the oil pipes between the two hydraulic cylinders are all connected to the oil pump, enabling the strokes of the two hydraulic cylinders to have a linkage effect, thus achieving the effect of assisting steering and ensuring the safety of the RV during driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a top view structural schematic diagram of the present invention;

[0031] Figure 2 is a front sectional view structural schematic diagram of the connecting piece of the present invention;

[0032] Figure 3 is a structural schematic diagram of the U-shaped screw connection of the present invention;

[0033] Figure 4 is a side view structural schematic diagram of the connecting piece of the present invention;

[0034] Figure 5 is a front sectional view structural schematic diagram of the auxiliary rod of the present invention;

[0035] Figure 6 is a side view structural schematic diagram of the U-shaped screw of the present invention.

[0036] In the figure: 1, the first connecting frame; 2, the cross beam; 3, the auxiliary rod; 4, the connecting piece; 5, the positioning rod; 6, the second connecting frame; 7, the U-shaped screw; 8, the first positioning block; 9, the hydraulic cylinder; 10, the oil pipe; 11, the steering module; 12, the oil pump; 13, the first pin; 14, the mounting plate; 15, the connection module; 16, the transmission line; 17, the controller; 18, the second pin; 19, the second positioning block; 20, the first limiting tube; 21, the bushing; 22, the second limiting tube; 23, the linear bearing; 24, the hydraulic rod. DETAILED DESCRIPTION OF THE INVENTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] See also Figures 1 to 6 , four embodiments provided by the present invention are:

[0041] Embodiment 1:

[0042] A motorhome connection device with an auxiliary safety mechanism comprises a crossbeam 2, an auxiliary rod 3, a connecting piece 4, a positioning rod 5, a second connecting frame 6, a hydraulic cylinder 9, a steering module 11, an oil pump 12 and a controller 17. A connecting piece 4 is provided on one side of the crossbeam 2, and a second connecting frame 6 is provided on the end of the connecting piece 4 away from the crossbeam 2. A symmetrically distributed first connecting frame 1 is welded on both sides of the lower surface of the crossbeam 2. The crossbeam 2 and the connecting piece 4 are rotatably connected, and a first latch 13 is plugged into the rotatable connection. One side of the second connecting frame 6 is plugged into the inside of the connecting piece 4, and a symmetrically distributed second latch 18 is plugged between the second connecting frame 6 and the connecting piece 4. Bolts are rotatably plugged into the lower ends of the first latch 13 and the second latch 18 for positioning the first latch 13 and the second latch 18. The first connecting frame 1 is connected to the rear end traction beam of the vehicle, and the second connecting frame 6 is connected to the traction beam of the trailer. The height of the first connecting frame 1 is lower than the height of the crossbeam 2 and the second connecting frame 6.

[0043] On both outer walls of the two ends of the connecting member 4 away from the cross beam 2, positioning rods 5 are rotatably installed. The positioning rods 5 are both in contact with the surface of the second connecting frame 6. On the outer walls of both ends of the positioning rods 5, second positioning blocks 19 are symmetrically welded. A U-shaped screw rod 7 is inserted into the surface of the second positioning blocks 19. The U-shaped screw rod 7 is sleeved on the surfaces of the positioning rods 5 and the second connecting frame 6, and is used to fix the positioning rods 5 to the second connecting frame 6. The positioning rods 5 are stably connected to the second connecting frame 6, increasing the connection stability between the second connecting frame 6 and the connecting member 4.

[0044] Embodiment Two:

[0045] On the opposite surfaces of the cross beam 2 and the positioning rods 5, first positioning blocks 8 are welded. An auxiliary rod 3 is rotatably installed between the first positioning blocks 8. Hydraulic cylinders 9 are arranged inside the auxiliary rods 3; the auxiliary rod 3 is composed of a first limiting tube 20 and a second limiting tube 22. The first limiting tube 20 is inserted into the upper end inside the second limiting tube 22;

[0046] The hydraulic cylinder 9 is located inside the second limiting tube 22, and a hydraulic rod 24 connected to the inner wall of the top end of the first limiting tube 20 is arranged at the upper end of the hydraulic cylinder 9;

[0047] A bushing 21 is arranged at the upper end of the second limiting tube 22, and a linear bearing 23 is embedded inside the bushing 21, which is used to reduce the friction between the second limiting tube 22 and the first limiting tube 20.

[0048] The bottom end of the hydraulic cylinder 9 is provided with an oil pipe 10 penetrating through the outer wall of the auxiliary rod 3, and the oil pumps 12 are both connected to the oil pipe 10. The auxiliary rod 3 provides lateral limitation between the positioning rod 5 and the cross beam 2, and can keep both the positioning rod 5 and the cross beam 2 on the same horizontal plane, which can improve the anti-torsion strength between the connecting member 4, the cross beam 2 and the second connecting frame 6, and avoid the problem that when the vehicle turns at a too high speed, the rear trailer compartment tilts and causes torsion to the connecting member 4, ensuring the service life of the connecting member 4.

[0049] Embodiment Three:

[0050] An installation plate 14 is welded on the lower surface of the cross beam 2. An oil pump 12 is installed on the upper surface of the installation plate 14. A controller 17 is arranged on one side of the oil pump 12. The controller 17 is connected to the steering module 11.

[0051] The controller 17 is connected to the oil pump 12, and the controller 17 and the steering module 11 are connected by a transmission line 16. The steering module 11 is placed in the steering assembly, and is used to detect the steering and transmit signals to the controller 17, for the linkage of the two auxiliary rods 3 to adapt to the steering angle between the vehicle and the trailer;

[0052] On the side of the oil pump 12 away from the controller 17, there is a connection module 15. On both sides of the connection module 15, there are communicating connection nozzles for connecting the brake pipes between the vehicle and the trailer. The hydraulic cylinders 9 and the oil pump 12 system provided in the auxiliary rod 3 can be adaptively adjusted in accordance with the direction of vehicle steering. Moreover, the oil pipes 10 between the two hydraulic cylinders 9 are all connected to the oil pump 12, enabling the strokes of the two hydraulic cylinders 9 to have a linkage effect, thereby achieving the effect of assisting steering and ensuring the safety during the driving of the RV.

[0053] Embodiment 4:

[0054] The connection method is as follows:

[0055] S1: Connect the first connection frame 1 to the rear towing beam of the vehicle and the second connection frame 6 to the towing beam of the trailer respectively;

[0056] S2: Insert the second connection frame 6 into the inside of the connecting member 4 and fix it with the second pin 18. Subsequently, fit the positioning rod 5 to the surface of the second connection frame 6, and sleeve the U-shaped screw rod 7 on the surfaces of the positioning rod 5 and the second connection frame 6. Tighten the nut to stably connect the positioning rod 5 and the second connection frame 6;

[0057] S3: Connect the steering module 11 to the controller 17 through the transmission line 16, and adaptively connect the vehicle brake pipe and the trailer brake pipe through the connection module 15.

[0058] In S2 of the connection method based on the RV connection device:

[0059] After the second connection frame 6 is stably connected to the connecting member 4, calibrate the auxiliary rod 3, adjust the positions between the vehicle and the trailer, keep the vehicle and the trailer on the same axis, and synchronize the stroke of the hydraulic rod 24 to extend.

[0060] In S3 of the connection method based on the RV connection device:

[0061] During the driving of the vehicle, the steering module 11 can identify the rotation direction and rotation angle of the steering assembly. The steering module 11 outputs a signal to the controller 17, and the controller 17 adjusts the forward and reverse rotation of the oil pump 12 according to the output signal, pumps hydraulic oil into the hydraulic cylinder 9 corresponding to the reverse position of the steering, and the hydraulic oil in the hydraulic cylinder 9 at the corresponding position of the steering is pumped out through the negative pressure of the oil pump 12 to assist in power steering between the trailer and the vehicle.

[0062] Working principle: During the driving of the vehicle, the steering module 11 can identify the rotation direction and rotation angle of the steering assembly. The steering module 11 outputs a signal to the controller 17, and the controller 17 adjusts the forward and reverse rotation of the oil pump 12 according to the output signal, pumps hydraulic oil into the hydraulic cylinder 9 corresponding to the reverse position of the steering, and the hydraulic oil in the hydraulic cylinder 9 corresponding to the steering position is pumped out by the negative pressure of the oil pump 12, which can be adaptively adjusted according to the direction of the vehicle steering. Moreover, the oil pipes 10 between the two hydraulic cylinders 9 are all connected to the oil pump 12, so that the strokes of the two hydraulic cylinders 9 can have a linkage effect, assisting in power steering between the trailer and the vehicle, and ensuring the safety during the driving of the motorhome.

[0063] The positioning rod 5 is stably connected to the second connecting frame 6, increasing the connection stability between the second connecting frame 6 and the connecting member 4. Cooperating with the auxiliary rod 3 to laterally limit between the positioning rod 5 and the cross beam 2, the positioning rod 5 and the cross beam 2 can be kept on the same horizontal plane, which can improve the anti-torsion strength between the connecting member 4, the cross beam 2 and the second connecting frame 6, avoiding the problem that when the vehicle turns at too high a speed, the rear trailer compartment tilts and causes torsion to the connecting member 4, and ensuring the service life of the connecting member 4.

[0064] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A motorhome connection device with an auxiliary safety mechanism, comprising a cross beam (2), an auxiliary rod (3), a connecting member (4), a positioning rod (5), a second connecting frame (6), a hydraulic cylinder (9), a steering module (11), an oil pump (12) and a controller (17), characterized in that: A connecting member (4) is provided on one side of the cross beam (2), a second connecting frame (6) is provided on one end of the connecting member (4) facing away from the cross beam (2), first connecting frames (1) are welded to both sides of the lower surface of the cross beam (2) and are symmetrically distributed, positioning rods (5) are rotatably mounted on both sides of the outer walls of the end of the connecting member (4) facing away from the cross beam (2), first positioning blocks (8) are welded on the surface of the side opposite to the positioning rod (5), auxiliary rods (3) are rotatably mounted between the first positioning blocks (8), and hydraulic cylinders (9) are arranged inside the auxiliary rods (3); A mounting plate (14) is welded to the lower surface of the crossbeam (2), an oil pump (12) is mounted on the upper surface of the mounting plate (14), a controller (17) is provided on one side of the oil pump (12), and the controller (17) is connected to the steering module (11); The first connecting frame (1) is connected to the traction beam at the rear end of the vehicle, and the second connecting frame (6) is connected to the traction beam of the trailer; The height of the first connecting frame (1) is lower than the height of the crossbeam (2) and the second connecting frame (6); The positioning rods (5) are in contact with the surface of the second connecting frame (6), and the outer walls at both ends of the positioning rods (5) are symmetrically welded with second positioning blocks (19); A U-shaped screw rod (7) is inserted into the surface of the second positioning block (19), and the U-shaped screw rod (7) is sleeved on the surfaces of the positioning rod (5) and the second connecting frame (6) to fix the positioning rod (5) and the second connecting frame (6).

2. The RV connection device with an auxiliary safety mechanism according to claim 1, characterized in that: The crossbeam (2) and the connecting member (4) are rotatably connected, and a first latch (13) is inserted into the rotatable connection; One side of the second connecting frame (6) is plugged into the interior of the connecting piece (4), and symmetrically distributed second latches (18) are plugged between the second connecting frame (6) and the connecting piece (4); Bolts are rotatably inserted at the lower ends of the first latch pin (13) and the second latch pin (18), and are used to position the first latch pin (13) and the second latch pin (18).

3. The RV connection device with an auxiliary safety mechanism according to claim 1, characterized in that: The auxiliary rod (3) is composed of a first position limiting tube (20) and a second position limiting tube (22), wherein the first position limiting tube (20) is inserted into the interior of the upper end of the second position limiting tube (22); The hydraulic cylinder (9) is located inside the second position limiting tube (22), and a hydraulic rod (24) connected to the inner wall of the top end of the first position limiting tube (20) is provided at the upper end of the hydraulic cylinder (9); The upper end of the second position limiting tube (22) is provided with a shaft sleeve (21), and a linear bearing (23) is embedded and installed inside the shaft sleeve (21) to reduce friction between the second position limiting tube (22) and the first position limiting tube (20).

4. The RV connection device with an auxiliary safety mechanism according to claim 1, wherein: An oil pipe (10) penetrating the outer wall of the auxiliary rod (3) is provided at the bottom end of the hydraulic cylinder (9), and the oil pump (12) is connected to the oil pipe (10).

5. The RV connection device with an auxiliary safety mechanism according to claim 1, characterized in that: The controller (17) is connected to the oil pump (12), and the controller (17) is connected to the steering module (11) by a transmission line (16); the steering module (11) is placed in the steering assembly and is used to detect the steering and transmit a signal to the controller (17) for the two auxiliary rods (3) to be linked to adapt the steering angle between the vehicle and the trailer; On the side of the oil pump (12) facing away from the controller (17), a connection module (15) is provided. On both sides of the connection module (15), there are connected connecting nozzles for connecting the brake pipes between the vehicle and the trailer.

6. A connection method for a motorhome connection device with an auxiliary safety mechanism according to any one of claims 1 to 5, characterized in that: The connection method is as follows: S1: Connect the first connecting frame (1) to the rear towing beam of the vehicle and the second connecting frame (6) to the towing beam of the trailer respectively; S2: Insert the second connecting frame (6) into the inside of the connecting piece (4) and fix it with the second pin (18). Then, fit the positioning rod (5) to the surface of the second connecting frame (6), and sleeve the U-shaped screw rod (7) on the surfaces of the positioning rod (5) and the second connecting frame (6). Tighten the nut to stably connect the positioning rod (5) and the second connecting frame (6); S3: Connect the steering module (11) to the controller (17) through the transmission line (16), and adaptively connect the vehicle brake pipe and the trailer brake pipe through the connection module (15).

7. The connection method of a motorhome connection device with an auxiliary safety mechanism according to claim 6, characterized in that: In S2 of the connection method based on the RV connection device: After the second connecting frame (6) is stably connected to the connecting piece (4), calibrate the auxiliary rod (3), adjust the positions between the vehicle and the trailer, keep the vehicle and the trailer on the same axis, and extend the hydraulic rod (24) for synchronous stroke adjustment.

8. The connection method of a motorhome connection device with an auxiliary safety mechanism according to claim 6, characterized in that: In S3 of the connection method based on the RV connection device: During the vehicle driving process, the steering module (11) can identify the rotation direction and rotation angle of the steering assembly. The steering module (11) outputs a signal to the controller (17), and the controller (17) adjusts the forward and reverse rotation of the oil pump (12) according to the output signal, pumps hydraulic oil into the hydraulic cylinder (9) corresponding to the reverse position of the steering. The hydraulic oil in the hydraulic cylinder (9) corresponding to the steering position is pumped out through the negative pressure of the oil pump (12) to assist in power steering between the trailer and the vehicle.

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