A FIFTH WHEEL SYSTEM Field of the Invention

The present invention relates to a fifth wheel system the rigidity of which is preserved even though its weight is reduced, and which can be applied at lower heights than the present systems.

Background of the Invention

Fifth wheel systems enable the connection between the trailer and the cap of the towing vehicle. The connection between the trailer and the vehicle of towing type is achieved by the connection of the kingpin which is in a mounted state under the trailer, to the fifth wheel.

In the present usage, the fifth wheel system consists of three parts, these parts being fifth wheel top plate/coupling, fifth wheel pedestal and the mounting plate. The fifth wheel top plate/coupling is connected to the mounting plate by means of the pedestals. Meanwhile the mounting plate is connected to L brackets. As drilling a hole in the chassis arms' upper flange is not a preferred design method, the mounting plate is connected to the chassis of the vehicle by means of L brackets which are attached to the two sides of the chassis arms.

One of the objectives of the mounting plate is to provide extra rigidity to the coupling of the fifth wheel which is generally produced of cast material, and thus prevent it to be damaged under the loads that are stemming from the trailer. This is why attention needs to be paid so that the design of the mounting plate is realized in a manner that it provides a rigid structure. Where, generally the corrugated forms that are built on the plate provide this rigidity. By this way, the endurance of the coupling against bending/breaking is increased. As the fifth wheels are security pieces, the security of the connection is extremely important, and the cracking and breaking of the parts during usage is absolutely unwanted. Another objective of the mounting plate is to provide a robust connection by transferring the loads that are incident on the fifth wheel to the chassis, in a distributed manner. By this way, the incident loads are distributed in a wide area in a homogenous manner. The loads stemming from the trailer are transmitted to the fifth wheel via the kingpin. As the loads that are transferred to the chassis from the trailer are quite great, the fifth wheel system needs to be positioned on one of the most robust zones of the vehicle. Because of this, the chassis cross and the cast suspension bracket are also positioned really close to the area to at which the fifth wheel will be attached to the chassis, and by this, this area is strengthened.

In practice, the first of the most encountered problems is that the parts are heavy. The fifth wheel connection is located to a robust area of the vehicle. In order to increase the endurance, the casted suspension bracket positioned to the chassis so that it centers the fifth wheel with respect to the x-axis of the vehicle. Even though the main function of these brackets is to hold the I-arms, they are also designed in order to improve the robustness of the design and to strengthen the area to which they are connected. The suspension brackets are important because of this. Additionally, by using a cross named fifth wheel cross under the fifth wheel, the chassis arms are strengthened against the loads stemming from the fifth wheel. The cross is generally formed by connecting two C-profiles back-to-back, and they attach the two arms of the chassis to each other via the brackets named gussets. As the cross is desired to be structurally rigid, the parts that are used are produced quite big and heavy. The total weight of this system is about 50 kgs. The fifth wheel cross and the gussets do not have any other function than provide rigidity to this area of the vehicle. Additionally, the fifth wheel coupling is connected to the mounting plate by means of the pedestals. The weight of the mounting plate is about 50-60 kgs. The pedestals are also heavy parts which are produced of casted material, and their total weights are about 50-60 kilograms. With the L brackets to which the mounting plate is connected, it is aimed to uniformly distribute the load that is stemming from the fifth wheel to the chassis, and the weight of these parts is about 40 kgs. As a result, it is needed that improvements in the weight are made using lighter parts with the equivalent design properties in the system. Another widely encountered problem is that the kingpin connection cannot be located too low in the z-axis of the vehicle. The drivers, in the long-distance transportation, want this distance to be as short as possible, as a matter of fact, they want it as close to the body upper flange as possible. By this way, they can use a trailer of a bigger volume without exceeding the trailer upper height limit that is allowed by the highways. However, as it can be seen, the pedestals, the mounting plate and the L brackets prevent this distance from being reduced.

In the United States patent document numbered US20100237587(A1) in the background of the invention, the connection of the fifth wheel structure to the vehicle is disclosed. In this document, it is stated that the height of the fifth wheel can be adjusted by means of the connection points that are present on the fifth wheel mounting piece. At the same time, it is stated that shock absorbers can be used for absorbing the loads. However, the fifth wheel system that is disclosed in the said document do not comprise a chassis cross having a geared cross-section, and shock absorbers that are placed on the suspension bracket.

In the United States patent document numbered US2013168946A1 that is present in the background of the invention, similarly, the connection of the fifth wheel structure to the vehicle is disclosed. In this document, the suspension bracket is used for mounting the pedestals of the fifth wheel. In this technique, as the mounting plate is removed, the pedestals are connected to each other via a cross located in between them. By this way, the reduction of bending of the fifth wheel coupling is intended. However, a solution relating to the cross which needs to be located under the fifth wheel is not proposed. It is possible that the cross that is connecting the pedestals to each other is insufficient to carry out the function of the fifth wheel cross of the chassis. In this document, the objective is to locate fifth wheel system in a lower position instead of reducing the weight of the vehicle. Because, even though the mounting plate is removed, the weight of the inter-pedestal cross that is substituted will be similar. Objects of the Invention

The object of the invention is to provide a fifth wheel system which enables weight reduction by cancelling the mounting and connection plates. Another object of the invention is to provide a fifth wheel system which comprises load absorbing parts.

Another object of the invention is to provide a fifth wheel system which allows the height of the fifth wheel to be reduced.

Another object of the invention is to provide a fifth wheel system which comprises a fifth wheel which gains load absorbing function by the virtue of its design. Short Description of the Invention

The present invention is related to a fifth wheel system which is used in the heavy commercial vehicles of towing type, which can be applied at lower heights and which enables the weight reduction by the cancelling of the mounting and connection plates, besides that the rigidity of which is preserved, which comprises a cross which have a geared cross-section and a hollow structure, which comprises absorbing parts for damping heavy loads that are stemming from the trailer and which adds the function of load damping to the fifth wheel.

Detailed Description of the Invention

A fifth wheel system in order to fulfill the objects of the present invention illustrated in the attached figures, where:

Perspective view of the fifth wheel system.

Perspective view of the fifth wheel system in the exploded state.

Perspective view of the fifth wheel system from another angle.

Perspective view of the fifth wheel system from another angle.

Perspective view of the bracket.

Perspective view of the cross.

View of the dampers with the incident loads.

Elements shown in the figures are individually numbered, and the correspondence of these numbers are given as follows:

Fifth wheel system

Fifth wheel

2.1. Housing

Cross

3.1. Inner channel

3.2. Outer channel

Bracket

4.1. Protrusion

4.2. Extension

4.3. Connection member

4.4. Recess

4.5. Connection hole 5. Damper

5.1. Connection means

6. Connection bracket

6.1. Damper connection

6.2. Wheel connection

S. Chassis

The fifth wheel system (1) which is used in the heavy commercial vehicles of towing type, which can be applied at lower heights and which enables the weight reduction by the cancelling of the mounting and connection plates, besides that the rigidity of which is preserved, which comprises absorbing parts for damping heavy loads that are stemming from the trailer essentially comprises;

at least one fifth wheel (2) which enables connection between the trailer and the kingpin, and which has a load damping feature by the virtue of the geometry it has,

at least one cross (3) which is located between the chassis (S) arms, which has a certain wall thickness, which is of a hollow structure and on which, channels lying through its axis are present,

at least one bracket (4) which enables connection between the cross (3) and the chassis (S),

at least one damper (5) which damps the loads stemming from the trailer to a certain extent, which is fixed on the bracket (4) at a certain angle in order to counter the horizontal loads that would be generated during the acceleration of the vehicle, one end of which is connected to the bracket (4) and the other end of which is connected to the fifth wheel (2),

at least one connection bracket (6) which enables connection between the fifth wheel (2) and the damper (5).

In one embodiment of the invention, the fifth wheel system (1) comprises a fifth wheel (2) on which housings (2.1) having a groove shape are present, and which is preferably produced by casting. The housings (2.1) that are present on the fifth wheel (2) adds the function of load damping to the fifth wheel (2), and by this, the present mounting plate is removed. In the fifth wheel system (1), a cross (3) which is placed between the legs of the chassis (S), which is preferably produced in a cylindrical geometry, which has a certain wall thickness and which is hollow is present. On the cross (3), inner channels (3.1) and outer channels (3.2) which extend through its axis are present. By this structure, the cross (3) has a structure that is similar to a gearwheel. By the usage of the cross (3) that has a gearwheel cross-section, the gussets and the cross having a C cross section are removed. The cross (3) is preferably produced by the aluminum or steel extrusion method. In order to enable mounting of the cross (3) that has the hollow gearwheel cross- section to the arms of the chassis, two brackets (4) are used. The bracket (4) can be produced by casting. The outer channels (3.2) that are present on the cross (3) might intertwine with the protrusions (4.1) that are present on the bracket (4) or, for the ease of production, the joining ends might be cut straight. Afterwards, the cross (3) is preferably welded with the bracket (4) at its both ends. In the case where the cross (3) is produced of aluminum, the cast brackets (4) are also produced of aluminum cast. The welding method of these is the method for welding aluminum. In the case where the cross (3) is produced of a steel material which has a thin wall thickness, the brackets (4) are produced of cast iron which has similar carbon ratios to the one of the cross (3) and which preferably has spheroidal graphite of type GGG, and its connection is achieved by "forge welding". The bracket (4) has two extensions (4.2) On the extension (4.2) a recess (4.4) through which the end of the damper (5) that is connected with the bracket (4) pass is located. Preferably on each one of the both two ends of the damper (5), one connection means (5.1) is present. One of these connection means (5.1) that are present in the damper (5) is snapped in to this recess (4.4), and the connection means (5.1) that is present at the end of the damper (5) is connected by the connection member (4.3). The brackets (4) are attached to the chassis (S) via the one apiece connection members that are snapped in to the connection members (4.5) that are present on the brackets (4). The dampers (5) are connected to the bracket (4) and to the fifth wheel (2) via the connection means (5.2) that are present on its two ends. Meanwhile, the connection between the damper (5) and the fifth wheel (2) is established via the connection bracket (6). Connection bracket (6) comprises a damper connection (6.1) that is connected to the damper (5), and a fifth wheel connection (6.2) that is connected to the fifth wheel (2). In order to balance the moment that is stemming from the trailer, the dampers (5) give freedom to the fifth wheel (2) around the y-axis by the virtue of the shaft hubbed connection that is present at the connection area. In the fifth wheel system (1), four dampers (5) for each vehicle is used instead of the pedestals, two of them being in the left side and two of them being in the right side. In order to damp the loads (U) that are stemming from the trailer and damp the loads that are generated during accelerating/braking, the dampers (5) are placed in the direction of the vector components (Di and D ₂ ) of these forces. Additionally, the dampers (5) can be placed at any preferred location. The operation of the fifth wheel system (1) is as follows. The cross (3) that has the geared cross-section which is placed between the chassis (S) arms with the help of the brackets (4) is connected to the fifth wheel (2) with the help of the dampers (5). The trailer is attached to the fifth wheel (2) with the help of the kingpin. When the vehicle starts moving, the dampers (5) damp the loads (U) that are stemming from the trailer and that are being transferred through the fifth wheel, and also the loads (D) that are caused by the acceleration/braking. By the usage of the cross (3) that has a gearwheel cross-section, the gussets and the cross having a C cross section are removed, and the high rigidity requirement of this connection is eliminated. By welding the hollow cross (3) having the gearwheel cross-section and the brackets (4) to each other, the leak tightness of the cross (3) is achieved, and the empty volume that is inside the cross (3) could be used for storing air, fuel or urea if the necessity occurs. By the usage of the cross (3) that has a gearwheel cross-section and the damper (5), the cross having a C cross section, the gussets, L brackets and the pedestals are removed. By the usage of the fifth wheel (2) having groove shaped housings (2.1) and having the capability to damp loads, the mounting plate is removed. By removing all of these said parts, the weight is significantly reduced. Additionally, the fifth wheel system is positioned lower, and they can use a trailer of a bigger volume without exceeding the trailer upper height limit that is allowed by the highways.