FIFTH WHEEL SYSTEM Field of the Invention

The present invention relates to a fifth wheel system which enables the trailer to be connected to the chassis of the towing vehicle in vehicles of heavy commercial towing type, the weight of which is reduced, and at the same time the rigidity of which is preserved, and which can be designed at lower heights than its present state.

Background of the Invention

The vehicles of heavy commercial towing type are heavily used in haulage. The transportation of various loads such as articles, containers, fuel, concrete, cement, soil, iron, aggregate is heavily performed by vehicles of towing type According to specifications of the load to be carried such as the capacity, size and type, road vehicles having a purpose of transportation such as prime mover, semi-trailer, trailer and so forth are used. By connecting a load carrying vehicles such as trailers, prime movers and so forth to the back of the vehicles of towing type, high capacity transportation is achieved. In the vehicles of heavy commercial towing type, the connection of the trailers and prime movers and so forth is achieved by the fifth wheel and a connection member named king pin. The fifth wheel is present on the chassis of the tower vehicles and is mounted on the chassis and the chassis arm of the vehicle. The king pin is a mounting piece which is present on the trailer and which enables the trailer to be connected to the fifth wheel and which is produced of steel. The connections of the load carriers such as trailers to the tower vehicles is achieved by the fifth wheel and the king pin. The king pin that is present on the trailer (prime mover) snaps into the fifth wheel and gets securely locked, by this way the connection between the tower vehicle and the trailer is established. In the fifth wheel connection in the state of the art, the following parts are present: wheel coupling, wheel pedestal and mounting plate (Figure 2). The wheel coupling is brought over the mounting plate and is connected to the plate by means of the pedestals. Meanwhile the mounting plate is connected to L brackets and is fixed to the two sides of the chassis arms (Figure 3).

In the fifth wheel connection, the mounting plate provides extra rigidity to the wheel coupling, and prevents the wheel coupling from being crushed under the loads originating from the trailer. Because of the said reason, it is of capital importance that the mounting plate is of a rigid structure and it has a rigid design. The rigidity of the mounting plate is generally provided by the corrugated forms that are produced on the plate, and thus the resistances of the wheel coupling to the bending and breaking increase. As the fifth wheel connection is a safety connection, this connection should be secure and dependable, and it should not crack and/or break under any circumstances. The mounting plate, at the same time, distributes the loads coming in to the fifth wheel and transmits them to the chassis. By the virtue of the mounting plate, the loads that are imposed on the fifth wheel gets distributed on the area of the mounting plate homogenously and gets distributed.

In the fifth wheel connections, the loads arising from the trailer are transmitted on to the fifth wheel via the king pin. As the loads that are transferred to the chassis from the trailer are quite great, the fifth wheel region needs to be positioned on one of the most robust places of the vehicle. In order to achieve this, a chassis cross (connection support) and a casted suspension bracket is connected to the region around which the fifth wheel is going to be connected to the chassis, and thus the region is fortified. When the connection between the tower vehicle and the trailer is established, forces from multiple directions are exerted on the fifth wheel. One of the forces that are exerted to the fifth wheel is exerted by the trailer and it is in the vertical direction (U). Another force that is exerted on the fifth wheel is the force that the tower vehicle exerts in the horizontal direction and which arises from the acceleration and braking of the vehicle (D). The tower vehicle and the trailer are two vehicles that are independent from each other and they are connected to each other via the king pin and the fifth wheel. These two vehicles can be at the different road levels at the same time because of the reasons such as rugged terrain conditions, when the vehicle is going downhill, the tower being in a plane surface and the trailer being in a ramp or the tower being in the beginning of a ramp and the trailer being on a plane surface etc., and thus the king pin might try to get dislocated from the fifth wheel, or try to make an exact opposite movement, this in turn causes a bending moment(M) that is transmitted from the trailer to the fifth wheel. The fifth wheel needs to be in a rigid structure in order to be able to receive the forces that are being exerted on it in horizontal and vertical directions, and at the same time it has to be free around the y-axis in order to damp the bending moment (Figure 1).

There are some problems present in the fifth wheel systems that are being used in the state of the art. The most general problem of the presently used fifth wheel systems is that their weights are quite much. As the fifth wheel systems are quite heavy, in order to increase the endurance, a molded suspension bracket is connected to the region where the fifth wheel is connected to the chassis; by the connection of the suspension bracket, at the same time, the region under the wheel is strengthened. In order for the connection between the wheel and the chassis to be stronger, and for no bending to be formed on the chassis arms, connection cross is added between the chassis arms. The connection cross strengthens the structure, however, at the same time, it causes the structure to get very heavy. The fifth wheel coupling is connected to the mounting plate by means of the pedestals. The pedestals are also heavy parts which are produced of casted material, each one of them weighs about 40-60 kilograms. The mounting plate is connected to the chassis by means of L brackets. For the connection of the mounting plate, at least two L brackets are used and the total weight of the L brackets is about 40 kilograms. The presently used fifth wheel system comprises wheel cross, mounting plate, pedestals and L brackets, and the approximate total weight is about 200-210 kilograms.

Yet another technical problem in the state of the art is that the connection between the fifth wheel and the king pin is made at a high level and this level cannot be reduced. The drivers want the connection height of the fifth wheel to be as low 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. In the fifth wheel connection, some parts for preventing the reduction of the height, such as pedestals, mounting plates and L bracket are present. As the pedestals perform the duty of connection between the mounting plate and the coupling, it has to have a certain height. As the mounting plate is connected over the L brackets, they prevent the structure from being positioned lower. While the L brackets are positioned a little higher in order to prevent the mounting plate from touching the chassis flange when the mounting plate is bent under load. If the mounting plate and the L brackets had not been used in the present design, then the fifth wheel would have been approached to the chassis flange as much as possible.

In the state of the art, there are some applications for reducing the weight of the fifth wheel system and to position the location of the fifth wheel lower, are present. In the United States patent document numbered US2013168946A1 in the background of the invention, the suspension bracket is used for mounting the pedestals of the fifth wheel. In the said application, as a mounting plate is not used, the pedestals are connected to each other by placing a cross between the pedestals. By this way, the prevention of bending of the fifth wheel coupling is intended. By the said application, it is aimed to shift the fifth wheel system from its current location to a lower location. Using the said system, it is not possible to reduce the weight of the fifth wheel because the mounting plate is removed, however, instead of it, pedestals with similar weights are placed. Between the said United States patent document and the inventive application, there are serious differences present such as the parts of the system, the usage if the system parts and the mechanical structure. In the fifth wheel system that is the subject matter of the application the base of the wheel coupling has a corrugated form, and this way the wheel coupling carries out the duty of the mounting plate. In the fifth wheel system that is the subject matter of the application, a cross with an H profile that is connected to the brackets of the suspension is present, and the cross and the wheel coupling are mounted to each other via the shock absorber. In the said United States patent document, none of these features are present.

The international patent document numbered WO2012064183 (Al) in the background of the invention discloses a fifth wheel system in which mounting plates and L brackets are not used. In the fifth wheel system that is disclosed in the said document, in order to reduce the weight of the system, mounting plate and the L brackets are removed from the design. Upon removing the mounting plate, an additional connection is made from the cross of the fifth wheel to the coupling of the fifth wheel, and the rigidity that is supplied by the mounting plate is intended to be achieved this way. In the said invention, the freedom of the fifth wheel around the y-axis is completely prevented. By this way, the forces originating from the trailer are transmitted directly to the parts and this situation is not preferred. In the fifth wheel system that is the subject matter of the application the base of the wheel coupling has a corrugated form, and this way the wheel coupling carries out the duty of the mounting plate. In the fifth wheel system that is the subject matter of the application, a cross with an H profile that is connected to the brackets of the suspension is present, and the cross and the wheel coupling are mounted to each other via the shock absorber. In the said international patent document, none of these features are present. In the Great Britain patent document numbered GB2475965 in the background of the invention, a study has been carried on the coupling of the fifth wheel and the pedestals. In the fifth wheel system that is disclosed in the said patent document, a mounting plate is not used, the pedestals are connected via crosses, and in order to receive the moments stemming from the trailer, there is a freedom in the y-axis. In the said system, L brackets are still used and as required by the structure, crosses are also used. In the fifth wheel system that is the subject matter of the application the base of the wheel coupling has a corrugated form, and this way the wheel coupling carries out the duty of the mounting plate. In the fifth wheel system that is the subject matter of the application, a cross with an H profile that is connected to the brackets of the suspension is present, and the cross and the wheel coupling are mounted to each other via the shock absorber. In the said Great Britain patent document, none of these features are present. In the present applications, a fifth wheel system that is light in weight and at the same time that is of a rigid structure is not present. In the fifth wheel systems, a design where the mounting plate, L bracket and the pedestals are removed and where the rigidity is preserved is not present. An application where the base of the wheel coupling has a corrugated form, where an H profiled cross that is connected to the suspension brackets is present and where the wheel coupling is connected to the cross via the shock absorber is not present.

Objects of the Invention

The object of the invention is to provide a fifth wheel system which enables the trailer to be connected to the tower, which is lightweight and of a rigid structure.

Another object of the invention is to provide a fifth wheel system where mounting plate, L brackets and pedestals are not used. Yet another object of the invention is to provide a fifth wheel system the height of which from the ground is minimized, and which is positioned to the area that is the closest to the flange of the chassis. Short Description of the Invention

The fifth wheel system defined in the first claim and the dependent claims thereof in order to realize the objects of the present invention, comprises wheel coupling, shock absorber, connection support cross and suspension bracket. The king pin that is present on the trailer is connected to the wheel coupling. There is a housing (mount) present on the wheel coupling in which the king pin will fit. The base of the wheel coupling is of a corrugated form and thus its rigidity is improved. The wheel coupling is positioned on the chassis and the crosses. Shock absorber is present between the wheel coupling and the crosses, and by the virtue of the shock absorber the damping of the forces that are acting on the wheel coupling is achieved. On the suspension bracket, outward protrusions are present for the connection of the cross, and the suspension bracket is connected to the cross via these protrusions. In the fifth wheel system a lighter structure is achieved as the mounting plates, L brackets and pedestals are not used.

Detailed Description of the Invention

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

Figure 1. A schematic illustration showing the connection between the tower and the trailer and the incident forces over the fifth wheel system.

Figure 2. Exploded view of the fifth wheel system that is being used in the state of the art.

Figure 3. Mounting view of the fifth wheel system that is being used in the state of the art. Figure 4. Exploded view of the fifth wheel system that is being used in the state of the art.

Figure 5. Exploded view of the fifth wheel system.

Figure 6. Exploded view of the fifth wheel system.

Figure 7. Side view of a mounted fifth wheel system.

Figure 8. Front view of a mounted fifth wheel system.

Figure 9. Schematic view of the connection region of the fifth wheel system.

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

1. Fifth wheel system

2. Wheel coupling

21. King pin mount

22. Base

3. Damper

31. Shaft

32. Support piece

33. Damping member

34. Connection member

4. Cross

41. Side face

42. Middle piece

43. Connection hole

5. Suspension bracket

51. Cross mounting piece

S: Chassis arm

The fifth wheel system (1) which enables the trailer to be connected to the chassis of the towing vehicle in vehicles of heavy commercial towing type, the weight of which is reduced, and at the same time the rigidity of which is preserved comprises; - at least one wheel coupling (2) which is mounted to the cross (4) that is present on the chassis arm (S), and on which the king pin part is connected in order for the trailer to be connected to the tower vehicle,

- at least one damper (3) which is connected to the wheel coupling (2), which dampens the dynamic loads coming from the trailer to wheel coupling (2), and which provides the wheel coupling (2) with freedom around the y-axis,

- at least one cross (4) which is connected to the region where the wheel coupling (2) is to be fixed to the chassis arm (S). The inventive fifth wheel system (1) is connected over the chassis arm (S) in a robust and secure manner. The trailer that is to be towed by the heavy industrial tower vehicle is connected to the fifth wheel system (1) which is fixed to the cross

(4) that is present on the chassis arm (S). The king pin piece that is present on the trailer is fixed to the fifth wheel system (1) and thus the movement of the trailer together with the tower vehicle is ensured.

In the preferred embodiment of the invention, wheel coupling (2) comprises at least one king pin mount (21) and at least one base (22). The king pin that is present on the trailer is connected to the king pin mount (21) that is present on the wheel coupling (2). The king pin mount (21) is preferably in the middle of the wheel coupling (2). The king pin mount (21) is a mount which becomes narrower from outside to inside, and which preferably has a V shaped entrance. By this feature of the king pin mount (21) it becomes easy to snap the king pin piece into the mount (21).

In the surface of the wheel coupling (2) that is supposed to fit to the chassis arm

(5) , preferably in the whole lower surface of the wheel coupling (2) the base (22) is present. The base (22) sits directly on the chassis cross (4) which is present on the chassis arms (S). In the preferred embodiment of the invention, base (22) is of a corrugated form which has symmetrical indentations and protrusions. By the virtue of the base (22) that is present on the bottom part of the wheel coupling (2) having a corrugated form, the rigidity of the wheel coupling (2) is increased.

In the inventive fifth wheel system (1), the connection between the wheel coupling (2) and the cross (4) is realized by the damper (3). One end of the damper (3) is connected to the wheel coupling (2) and the other end of it is connected to the cross (4). The damper (3) enables the damping of the dynamic loads stemming from the trailer to the wheel coupling (2). The loads that are acting on the wheel coupling (2) are transferred directly to the damper (3). As the damper (3) damps a portion of or all of the loads that are acting on the wheel coupling (2), it reduces the amount of the loads that are acting on the chassis (S) and the cross (4). By this way, by the virtue of the damper (3), it is not required that the wheel coupling (3) and the chassis cross (4) to have a very robust, strong and rigid structure. As the damper (3) is mounted between the wheel coupling (2) and the cross (4), it damps the loads acting on the wheel coupling (2) and it transfers part of the loads to the cross (4).

In the preferred embodiment of the invention, the damper (3) comprises at least two shafts (31), at least one support piece (32), at least one damping member (33) and at least one connection member (34) (Figure 5). There is one shaft (31) present at each of the upper and lower part of the damper (3). The shafts (31) are preferably parallel to the ground. The upper shaft (31) if preferably directly connected to the damping member (33) and the damping member (33) is connected to the lower shaft (31) via the support piece (32) that is present at the bottom of it. The upper shaft (31) is connected to the wheel coupling (2) via the connection member (34). Inside of the wheel coupling (2) preferably mounts are present in which the shaft (31) and the connection member (34) will fit. When the shaft (31) of the damper (3) is connected to the wheel coupling (2) via the connection member (34) a hubbed connection is established and by this way the movement of the wheel coupling (2) in the y-axis is allowed. The damper (3) receives and damps the loads stemming from the trailer. By this way, the damper (3) serves the purpose of the pedestals. When the load stemming from the trailer reaches the wheel coupling (2), it is transferred to the upper shaft (31) via the connection member (34), and from there it is transferred to the damping member (33). When a load is inferred on the damping member (33), it gets compressed or stretched and thus absorbs the load. The damping member (3) damps forces according to its compression value. As the damping member (33), members providing the damping such as a spring, leaf spring, coil spring, elastic member, latex, hydraulic liquid and shock absorber are used. The damper (3) is connected to the wheel coupling (2) via the connection member (34), while it is connected to the cross (4) via connection pieces such as nuts and bolts.

The cross (4) is connected between the chassis arms (S). The cross (4) enables the chassis arms (S) to be connected to each other more robustly and the loads acting on the chassis arms to be more balanced. The cross (4) is preferably of an H-profile shape. The cross (4) might be of different shapes and designs. By the virtue of the cross (4) having the H-profile shape a strong rigidity and endurance is achieved. The cross (4) preferably comprises two side faces (41), at least one middle piece (42) and connection holes (43) which are present on the side face (41) and the middle piece (42). The inventive fifth wheel system (1) preferably comprises at least two suspension brackets (5). In the preferred embodiment of the invention, the cross (4), the suspension bracket (5) and the chassis arms (S) are connected to each other. Suspension bracket (5) comprises at least one cross mounting piece (51). On every suspension bracket (5), there is one cross mounting piece (51) present where the cross (4) connection is to be made. The cross mounting piece (51) is on the inside part of the suspension bracket (51) and it is shaped as a protrusion. The cross mounting pieces (51) that are present on the suspension bracket (5) pass from the holes, gaps or rebates that are present on the chassis arms (S) and thus provide connection area for the cross (4). By this way a durable and strong connection place for the cross (4) is created. The inventive fifth wheel system (1) preferably comprises at least one wheel coupling (2), at least one damper (3), at least one cross (4) and at least two suspension brackets (5). On the wheel coupling (2), a king pin mount (21) is present to which the king pin that is used for the trailer connection is to be snapped. The king pin piece is connected to the wheel coupling (2) and thus the movement of the trailer together with the tower vehicle is ensured. On the bottom surface of the wheel coupling (2) a base (22) of corrugated shape is present. By the virtue of the base (22) it is ensured that the wheel coupling (2) is of a rigid and durable structure. The base (22) serves the purpose of the mounting plate that is used in the previous art. The cross (4) is connected to the chassis arms (S) via the suspension brackets (5). The cross mounting piece (51) that is present on the suspension bracket (5) pass from the hole that is present on the chassis arms (S) and thus provide connection area for the cross (4) to be connected to the chassis arms (S). The cross (4) is positioned between the chassis arms (S) and is fixed to the cross mounting piece (51). When the cross (4) is fixed to the cross mounting piece (51) it is connected to both the chassis arms (S) and the suspension bracket. The wheel coupling (2) is positioned on the cross (4) and the connection between the wheel coupling (2) and the cross (4) is realized via the shock dampers (3). The connection of the damper (3) to the wheel coupling (2) is realized via the hubbed connection member (34). By this way, upon the moment exerted on the wheel coupling (2), the wheel coupling (2) can turn around the y-axis. The damping member (33) that is present inside the damper (3) provides the loads that are acting on the wheel coupling (2) to be damped and to be transferred to the cross (4). By the virtue of the damper (3) the usage of the pedestals that are used in the previous art is not necessary.