DESCRIPTION

TECHNICAL FIELD

[0001] The present disclosure relates to a slidably adjustable fifth wheel hitch assembly for a vehicle. More particularly, the disclosure relates to a fifth wheel assembly for a vehicle that automatically adjusts the distance between a trailer and the vehicle under certain appropriate operating conditions.

BACKGROUND

[0002] Over the last several years vehicle manufacturers and vehicle operators have worked to improve fuel efficiency of vehicles, so that vehicles may be less expensive to operate and meet more stringent fuel economy regulations. In some heavy-duty vehicles, such as semi trucks, or tractor-trailers, a vehicle is used to pull a trailer that contains cargo. The location where the trailer connects to the vehicle is often referred to as a fifth wheel, or a fifth wheel hitch. One approach to improving fuel economy involves decreasing the distance between the vehicle and the trailer during certain operating conditions by moving the fifth wheel. Positioning the trailer in closer proximity to the vehicle improves aerodynamics of the vehicle and trailer combination, thus increasing fuel economy of the vehicle. However, in other operating conditions, it may be a disadvantage to position the trailer close to the vehicle, such as during a turn, during rapid deceleration, during low speed operations, or if the trailer is loaded in a manner that positioning the trailer closer to the vehicle would violate axle weight restrictions set by government regulations.

[0003] Therefore, a need exists for a system capable of automatically positioning a trailer relative to a vehicle by moving a fifth wheel assembly based upon operating conditions of the vehicle and trailer.

SUMMARY

[0004] According to one embodiment, a vehicle having an adjustable fifth wheel hitch for positioning a trailer relative to the vehicle comprises a first vehicle frame rail, a second vehicle frame rail, a rear drive slider assembly, a front axle, and a cab portion. The second vehicle frame rail is disposed a fixed distance from the first frame rail and is generally parallel to the first frame rail. The rear drive slider assembly is positionable between a first position and a second position. The rear drive slider assembly comprises a first rear axle, a second rear axle, a suspension system, a hydraulic cylinder, and a fifth wheel hitch. The suspension system connects to the first rear axle and the second rear axle. The suspension system allows movement of the first rear axle and the second rear axle relative to a surface the vehicle travels over. The hydraulic cylinder has a fixed location relative to the first vehicle frame rail and the second vehicle frame rail. The hydraulic cylinder has a shaft connected to the suspension system. The hydraulic cylinder is adapted to position the shaft between an extended position and a retracted position. The fifth wheel hitch is connected to the suspension system. The fifth wheel hitch is fixedly positioned relative to the first rear axle and the second rear axle.

[0005] According to another embodiment, a vehicle having an adjustable fifth wheel hitch for positioning a trailer relative to the vehicle comprises a first vehicle frame rail, a second vehicle frame rail, a cross member, a rear drive slider assembly, a front axle, and a cab portion. The second vehicle frame rail is disposed a fixed distance from the first frame rail and is generally parallel to the first frame rail. The cross member is disposed between and connected to the first vehicle frame rail and the second vehicle frame rail. The rear drive slider assembly comprises a first rear axle, a second rear axle, a suspension system, a first frame rail passageway, a second frame rail passageway, a fifth wheel hitch, and a hydraulic cylinder. The suspension system connects to the first rear axle and the second rear axle. The first frame rail passageway is disposed in contact with the first frame rail. The second frame rail passageway is disposed in contact with the second frame rail. The fifth wheel hitch is connected to the suspension system. The fifth wheel hitch is fixedly positioned relative to the first rear axle and the second rear axle. The fifth wheel hitch is disposed above the first frame rail passageway and the second frame rail passageway. The fifth wheel hitch limits vertical movement of the first vehicle frame rail within the first frame rail passageway and the second vehicle frame rail within the second frame rail passageway. The hydraulic cylinder connects to the cross member. The hydraulic cylinder has a moveable shaft connected to the suspension system. The hydraulic cylinder is adapted to position the shaft between an extended position and a retracted position moving the rear drive slider assembly.

[0006] According to a further embodiment, a vehicle having an adjustable fifth wheel hitch for positioning a trailer relative to the vehicle comprises a first vehicle frame rail, a second vehicle frame rail, a rear drive slider assembly, a front axle, and a cab portion. The second vehicle frame rail is disposed a fixed distance from the first frame rail and is generally parallel to the first frame rail. The first vehicle frame rail and the second vehicle frame rail are disposed at a cab portion of the vehicle. The rear drive slider assembly comprises a first rear axle, a second rear axle, a third rear axle, a fourth rear axle, a plurality of electric motors, a first walking beam assembly, a second walking beam assembly, a suspension system, a fifth wheel hitch, a first cylinder clam half shell, a second cylinder claim half shell, a hydraulic cylinder, and a shaft. At least one electric motor is disposed at each of the first rear axle, the second rear axle, the third rear axle, and the fourth rear axle. The first rear axle and the second rear axle are connected to the first walking beam assembly. The third rear axle and the fourth rear axle are connected to the second walking beam assembly. The suspension system is connected to the first walking beam assembly and the second walking beam assembly. The fifth wheel hitch is connected to the suspension system. The fifth wheel hitch is fixedly positioned relative to the first rear axle, the second rear axle, the third rear axle and the fourth rear axle. The first cylinder clam half shell connects to the first vehicle frame rail. The second cylinder clam half shell connects to the second vehicle frame rail and the first cylinder clam half shell. The hydraulic cylinder is disposed between the first cylinder claim half shell and the second cylinder claim half shell. The shaft connects to the rear drive slider assembly and the hydraulic cylinder. The shaft is moved by the hydraulic cylinder between an extended position and a retracted position. The rear drive slider assembly is moved axially by the movement of the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a side view of a vehicle having an adjustable fifth wheel hitch with a rear drive slider assembly in a first position according to one embodiment.

[0008] FIG. 2 is a side view of the vehicle of FIG. 1 with the rear drive slider assembly in a second position.

[0009] FIG. 3 is a top view of the vehicle of FIG. 1 with the rear drive slider assembly in the first position.

[0010] FIG. 4 is a top view of the vehicle of FIG. 1 with the rear drive slider assembly in a second position.

[0011] FIG. 5 is partially exploded view of the rear drive slider assembly of FIG. 1.

[0012] FIG. 6 is a rear view of the rear drive slider assembly of FIG. 1.

[0013] FIG. 7 is a top view of a vehicle having an adjustable fifth wheel hitch with a rear drive slider assembly in a first position according to another embodiment. [0014] FIG. 8 is a top view of the vehicle of FIG. 7 with the rear drive slider assembly in a second position.

[0015] FIG. 9 is top view of the rear drive slider assembly of FIG. 7.

[0016] FIG. 10 is a partially exploded view of the rear drive slider assembly of FIG. 7.

DETAILED DESCRIPTION

[0017] FIG. 1 shows a vehicle 10, such as a semi-tractor. The vehicle 10 has a pair of frame rails 12a, 12b (FIG. 3) that run from a front end 14 to a back end 16 of the vehicle 10. The frame rails 12a, 12b typically are formed from high strength steel and provide structure for the vehicle 10. The frame rails 12a, 12b connect to a front axle 18. The front axle 18 is a steering axle in that tires disposed at outward ends of the front axle 18 are moveable to steer the vehicle 10. A first rear axle 20 and a second rear axle 22 also are connected to the frame rails 12a, 12b. The first rear axle 20 and the second rear axle 22 are drive axles, in that power is transferred through the rear axles 20, 22 to move the vehicle 10. The first rear axle 20 and the second rear axle 22 are connected to the frame rails 12a, 12b via a rear drive slider unit 24 described more fully in connection with FIG. 5, below. A fifth wheel hitch 26 also attaches to the rear drive slider unit 24.

[0018] The rear drive slider unit 24 is adapted to allow a position of the rear axles 20, 22 and the fifth wheel hitch 26 to move longitudinally along the frame rails 12a, 12b in order to allow a trailer to be positioned closer to the vehicle 10 in certain operating conditions. FIG. 1 shows the rear drive slider unit 24 positioned a first distance Dl from a side wind deflector 28 of the vehicle 10. The distance Dl is the maximum distance the rear drive slider unit 24 is positioned from the wind deflector 28. A top wind deflector 29 is also provided to direct airflow over the top of a front portion of trailer pulled by the vehicle 10.

[0019] FIG. 2 shows the rear drive slider 24 displaced towards the front end 14 of the vehicle 10, so that the rear drive slider 24 is positioned a second distance D2 from the wind deflector 28 of the vehicle 10. The distance D2 is the minimum distance the rear drive slider unit 24 is positioned from the wind deflector 28. Thus, the distance D2 is less than the distance D 1.

[0020] As can be observed in FIG. 2, the movement of the rear drive slider 24 displaces the rear axles 20, 22 and the fifth wheel hitch 26. Further, the spatial relationship between the rear axles 20, 22 and the fifth wheel hitch 26 is unchanged by the movement of the rear drive slider 24. Such an arrangement allows axle loading placed on the rear axles 20, 22 and the front axle 18 to remain generally identical as the rear drive slider 24 moves. This is beneficial as axle loading generally is not substantially changed by the movement of the rear drive slider 24, limiting the occurrence of the vehicle 10 exceeding government set axle load limits.

[0021] As also may be observed in FIGs. 1 and 2, the vehicle 12 has an overall length L. The overall length L is not affected by the movement of the rear drive slider 24, but rather is set by the frame rails 12.

[0022] FIGS. 3 and 4 show a top view of the vehicle 10 with the rear drive slider 24 positioned as shown in FIGs. 1 and 2, respectively. As shown in FIGs. 3 and 4, the fifth wheel hitch 26 has been removed for clarity. A suspension system 30, such as a Hendrickson HTB suspension, available through Hendrickson Truck Suspension Systems of Woodridge, IL, or other known suspensions, is provided to improve ride quality of the vehicle 10. The suspension system 30 also features a plurality of air bags 32 to further cushion the ride of the vehicle 10.

[0023] In order to move the rear drive slider 24, a hydraulic cylinder 34 provided. The hydraulic cylinder 34 may be a compound hydraulic cylinder. The hydraulic cylinder 34 has a shaft 36 that extends and retracts to adjust the position rear drive slider 24. The shaft 36 is typically a chrome polished machined shaft that may have multiple segments that collapse into one another to move the rear drive slider 24 towards and away from the wind deflector 28.

[0024] Turning to FIGs. 5 and 6, more detailed views of the rear drive slider 24 are shown. FIG. 5 shows a partially exploded view of the rear drive slider 24. The rear drive slider 24 is secured to the frame rails 12 via a first frame rail passageway 42 and a second frame rail passageway 44. The first and second frame rail passageways are generally U- shaped and have a generally flat flange portion disposed proximate a top portion of the frame rail passageways 42, 44. The flange portion is adapted to support a fifth wheel mounting plate 46. The fifth wheel mounting plate 46 is secured to the frame rail passageways 42, 44, by fasteners, such as huck bolts, but it is also contemplated that the mounting plate 46 may be welded to the frame rail passageways 42, 44. Thus the fifth wheel mounting plate 46, when attached to the frame rail passageways 42, 44 of the rear drive slider 24, restrains the rear drive slider 24 in a vertical position relative to the frame rails 12. The fifth wheel hitch 26 mounts to the fifth wheel mounting plate 46, thereby fixing the position of the fifth wheel hitch relative to the rear drive slider 24 and the first and second rear axles 20, 22.

[0025] FIG. 5 also shows the hydraulic cylinder 34. The hydraulic cylinder 34 has a moving end clevis 38 and a fixed end clevis 40. The moving end clevis 38 connects to the rear drive slider at a hitch 48. The fixed end clevis 40 connects to the vehicle 10 at a frame mounting location 50 (FIG. 3). It is contemplated that the frame mounting location 50 may be a cross member disposed between the frame rails 12.

[0026] FIG. 6 depicts clamps 52 that secure the first and second rear axles 20, 22 to the suspension system 30, and thereby the rear drive slider 24. The clamps 52 are generally identical to those used in conventional trucks with fixed fifth wheel hitch locations.

[0027] Thus, in order to move the rear drive slider 24, the hydraulic cylinder 34 is activated and the shaft 36 extends to move the rear drive slider 24 away from a cab portion 54 of the vehicle 10. Moving the rear drive slider 24 away from the cab portion 54 moves the fifth wheel hitch 26, and thereby increases a distance between a trailer and the vehicle 10. The rear drive slider 24 is moved away from the cab portion 54 in certain operating conditions, such as low speed operations where aerodynamic considerations are less important, when brakes are applied on the vehicle 10, or when the vehicle 10 is turning. The hydraulic cylinder 34 is activated to retract the shaft 36 to move the rear drive slider 24 closer to the cab portion 54 of the vehicle 10. Moving the rear drive slider 24 closer to the cab portion 54 moves the fifth wheel hitch 26 closer to the cab portion, thereby moving a trailer closer to the cab portion 54. Moving the trailer closer to the cab portion 54 of the vehicle 10 improves the aerodynamics of the vehicle and trailer combination, thereby reducing fuel consumption. Additionally, the movement of the fifth wheel hitch 26 with the rear drive slider 24 generally maintains loading of the rear axles 20, 22 and the front axle 18 irrespective of the position of the rear drive slider 24. Finally, the use of the hydraulic cylinder 34 allows for enhanced adjustability of the position of the rear drive slider 24, as it may be positioned in almost any intermediate position between the distance D 1 and the distance D2.

[0028] The rear drive slider 24 depicted in FIGs. 1-6 is adapted to be utilized with a vehicle 10 having a conventional powertrain, i.e., an engine that delivers power through a transmission to a differential that powers the rear wheels, or vehicle having a parallel-type hybrid-electric powertrain, where the rear wheels may be powered by a combination of power from an internal combustion engine and an electric motor.

[0029] FIG. 7 shows a vehicle 100, such as a semi-tractor. The vehicle 100 is a series type hybrid-electric vehicle in that electric motors 104 are utilized to provide power to move the vehicle 100, and an internal combustion engine is utilized to power an electric generator that generates electrical power used by the electric motors. The vehicle 100 has a pair of front frame rails 112a, 112b that run from a front end 1 14 to a back end 116 of a cab portion 102 of the vehicle 100. The frame rails 112a, 1 12b typically are formed from high strength steel and provide structural support for the vehicle 100. A front axle 1 18 connects to the frame rails 1 12a, 112b. The front axle 118 is a steering axle in that tires disposed at outward ends of the front axle 118 are moveable to steer the vehicle 100.

[0030] A rear drive slider unit 124 also is connected to the frame rails 112a, 112b. The rear drive slider unit 124 has a first walking beam assembly 106 and a second walking beam assembly 108. The first and second walking beam assemblies 106, 108 connect to first rear axles 120a, 120b respectively located on a right side and a left side of the vehicle 100. The first rear axles 120a, 120b each have an electric motor 104 adapted to provide power to wheels connected to the first rear axles 120a, 120b. Similarly, the first and second walking beam assemblies 106, 108 connect to second rear axles 122a, 122b respectively located on a right side and a left side of the vehicle 100. The second rear axles 122a, 122b each have an electric motor 104 adapted to provide power to wheels connected to the second rear axles 122a, 122b. The first rear axles 120a, 120b and the second rear axles 122a, 122b are drive axles, in that power is transferred through the rear axles 120a, 120b, 122a, 122b to move the vehicle 100. The first rear axle 120a and the second rear axle 122a are connected to the first walking beam assembly 106 and the first rear axle 120b and the second rear axle 122b are connected to the second walking beam assembly 108.

[0031] The rear drive slider unit 124 also comprises a fifth wheel hitch 126. The fifth wheel hitch 126 allows a trailer to be connected to the vehicle 100. The fifth wheel hitch 126 is generally disposed between the first rear axles 120a, 120b and the second rear axles 122a, 122b.

[0032] The rear drive slider unit 124 is adapted to allow a position of the rear axles 120a, 120b, 122a, 122b and the fifth wheel hitch 126 to move longitudinally, in order to allow a trailer to be positioned closer to the vehicle 100 in certain operating conditions, such as while driving at highway speeds on a generally straight roadway. FIG. 7 shows the rear drive slider unit 124 positioned a first distance D3 from the cab portion 102 of the vehicle 100. The distance D3 is the maximum distance the rear drive slider unit 124 is positioned from the cab portion 102.

[0033] FIG. 8 shows the rear drive slider 124 displaced towards the cab portion 102 of the vehicle 100, so that the rear drive slider 124 is positioned a second distance D4 from the cab portion 102 of the vehicle 100. The distance D4 is the minimum distance the rear drive slider unit 124 is positioned from the cab portion 102. Thus, the distance D4 is less than the distance D3. [0034] As can be observed in FIG. 8, the movement of the rear drive slider 124 displaces the rear axles 120a, 120b, 122a, 122b and the fifth wheel hitch 126. Further, the spatial relationship between the rear axles 120a, 120b, 122a, 122b and the fifth wheel hitch 126 is unchanged by the movement of the rear drive slider 124. Such an arrangement allows axle loading placed on the rear axles 120a, 120b, 122a, 122b and the front axle 1 18 to remain generally identical as the rear drive slider 124 moves. This is beneficial as axle loading generally is not substantially changed by the movement of the rear drive slider 124, limiting the occurrence of the vehicle 100 exceeding government set axle load limits.

[0035] FIGS. 9 and 10 show a top view of the rear drive slider 124 in an assembled and an exploded view, respectively. As shown in FIG. 9, the fifth wheel hitch 126 has been removed for clarity. A suspension system 130, is provided to improve ride quality of the vehicle 100. The suspension system 130 is an independent suspension that allows the first walking beam assembly 106 and the second walking beam assembly 108 to move up and down independently of one another in order to maintain wheel contact with the ground over a variety of surfaces. The first walking beam assembly 106 and the second walking beam assembly 108 are connected to the suspension system 130. The suspension system 130 additional is capable of rotating about tubular shaft 136. Thus, the suspension system 130 improves the ride of the vehicle 100 and allows the electric motors 104 to transfer power through the wheels of the vehicle 100 to the ground even on uneven surfaces. The suspension system 130 is axially fixed to the shaft 136, such that a change in length of the shaft 136 moves the suspension system 130, and the remainder of the rear drive slider 124 in an axial direction towards or away from the cab portion 102 of the vehicle 100. A front and rear stop may be welded to the shaft 136 to fix the position of the suspension system 130 to the shaft 136.

[0036] In order to move the rear drive slider 124, a hydraulic cylinder 134 provided. The hydraulic cylinder 134 may be a compound hydraulic cylinder. The hydraulic cylinder 134 moves the tubular shaft 136 that extends and retracts to adjust the position rear drive slider 124. The shaft 136 is typically a chrome polished machined shaft that is typically made from steel, but other materials may be utilized. Stops may be welded to the shaft 136 to limit the axial movement of the shaft 136 relative to the hydraulic cylinder 134.

[0037] The rear drive slider 124 is secured to the frame rails 1 12a, 112b via a first cylinder clam half shell 142 and a second cylinder claim half shell 144. The first and second cylinder clam half shells 142, 144 are generally identical and are adapted to connect to the frame rails 1 12a, 112b respectively, such as by being welded to the frame rails 112a, 1 12b. The cylinder clam half shells 142, 144 are attached to each other and form an enclosure to house the hydraulic cylinder 134. The cylinder clam half shells 142, 144 additionally support and constrain a portion of the shaft 136 by providing a bearing surface that the shaft 136 may slide against when moving between an extended and a retracted position, such as shown in FIGs. 7 and 8, respectively.

[0038] Thus, in order to move the rear drive slider 124, the hydraulic cylinder 134 is activated and the shaft 136 extends to move the rear drive slider 124 away from a cab portion 102 of the vehicle 100. Moving the rear drive slider 124 away from the cab portion 102 moves the fifth wheel hitch 126, and thereby increases a distance between a trailer and the vehicle 100. The rear drive slider 124 is moved away from the cab portion 102 in certain operating conditions, such as low speed operations where aerodynamic considerations are less important, when brakes are applied on the vehicle 100, or when the vehicle 100 is turning. The hydraulic cylinder 134 is activated to retract the shaft 136 to move the rear drive slider 124 closer to the cab portion 102 of the vehicle 100. Moving the rear drive slider 124 closer to the cab portion 102 moves the fifth wheel hitch 126 closer to the cab portion 102, thereby moving a trailer closer to the cab portion 102. Moving the trailer closer to the cab portion 102 of the vehicle 100 improves the aerodynamics of the vehicle 100 and trailer combination, thereby reducing fuel consumption. Additionally, the movement of the fifth wheel hitch 126 with the rear drive slider 124 maintains loading of the rear axles 120a, 120b, 122a, 122b and the front axle 1 18 irrespective of the position of the rear drive slider 124. Finally, the use of the hydraulic cylinder 134 allows for enhanced adjustability of the position of the rear drive slider 124, as it may be positioned in almost any intermediate position between the distance D3 and the distance D4.

[0039] As FIGs. 7-10 depict a vehicle 100 having a series type hybrid-electric powertrain with electric motors 104 at each rear axle 120a, 120b, 122a, 122b, a driveshaft is not required to run to a differential to provide power to the wheels.

[0040] The hydraulic cylinder 134 also is capable of providing a cushioning between the frame rails 112a, 112b and the rear drive slider 124. That is, the hydraulic cylinder 134 may be allowed to permit some motion of the shaft 136 in order to absorb axial forces transmitted from the fifth wheel hitch 126 to the rear drive slider 124, such as during braking or acceleration of the vehicle 100.