Patent Application
20140062049
Not Applicable
Not Applicable
Not Applicable
The automotive industry has seen many types of link-style suspension systems including ladder bar, torque arm, swing arm, three-link, and four-link suspension systems. Within the four wheel drive (4WD) community a coil sprung, coilover shock, or air-bag configured solid axle also requires a link-style suspension system. Those most widely used are the radius arm, three-link, and four-link. For example, Ford and Land Rover utilize a radius arm suspension system on their solid axle 4WD vehicles while Dodge Ram and Jeep utilize a four-link suspension system on their solid axle 4WD vehicles. Most link-style suspension systems need an additional link known as a Panhard bar or trackbar.
Currently, the preferred suspension system for solid axle 4WD vehicles is the triangulated 4-link suspension system. This is a suspension system consisting of four independent links where all links are located on the same side of an axle and where at least two links are angled. This preference is based on the observation that a triangulated 4-link suspension system is one of the best articulating suspension systems known. It also possesses the unique, and very important, characteristic of discarding the Panhard bar.
Articulation refers to the amount of vertical separation of an axle's wheels when the vehicle negotiates an obstacle. As the links are angled, they become more aligned with the axle. Greater alignment implies fewer propensities for the angled link to bind up in the bracket. During articulation, displacement of the angled links is minimized when one end of the link is attached to the center of the axle (viewing an articulated axle as a right triangle, displacement at the end of the axle is twice that at the center of the axle). Less displacement also implies fewer propensities for the angled link to bind up in the bracket. Less bind up in the bracket facilitates a greater amount of articulation by the wheels.
The Panhard bar is discarded because the angled links perform the Panhard bar's job of controlling the axle's lateral motion. While the Panhard bar imparts lateral motion, the angled links prevent it. When the suspension cycles up and down, the Panhard bar's rotational motion is reflected in a directly related lateral motion by the axle; whereas, under the same cyclic function the angled links hold the axle in a centered position beneath the vehicle. Although this lateral motion is not critical to a slow-moving off-road vehicle traversing rugged terrain, it can become problematic to a vehicle encountering un-even terrain at speed; e.g., street driving conditions. When attached to the steering front axle, a Panhard bar that is loose or worn out may transform this lateral motion into a harmonic oscillatory resonance known as “Death Wobble”. Death Wobble has been blamed for damage to the steering and suspension components on a vehicle.
These articulation and discarded Panhard bar features derive from the process of angling two of the four links in a triangulated 4-link suspension system. However during installation or cycling of this suspension system, the angled links may interfere with other components on a vehicle such as the engine, oil pan, gas tank, and exhaust. Thus, utilization of a triangulated 4-link suspension system is successful only when this interference is absent. In practice, absence of the interference is possible only for customized, purpose-built off-road vehicles and extraordinarily difficult for street driven vehicles.
In the late 1990s, builders of customized two wheel drive (2WD) trucks learned to circumvent this interference dilemma by moving the two angled links from the side of the axle where all four links are located to the opposite side of the axle. In so doing, they transformed the triangulated 4-link suspension system into a NEW suspension system where the two parallel links are on one side of the axle and the two angled links are on the other side of the axle. This new suspension system was popularly referred to as the 2-forward/2-reverse triangulated 4-link suspension system.
Although the 2-forward/2-reverse triangulated 4-link suspension system looks similar to the present invention, their design characteristics are very different. The 2-forward/2-reverse triangulated 4-link suspension system was designed for lowered 2WD trucks, and includes relatively short links and restricted travel/articulation properties; whereas, the present invention is designed for street-driven/“non-lifted” 4WD trucks, and includes relatively long links and unrestricted travel/articulation properties.
The 2-forward/2-reverse triangulated 4-link suspension system is shunned by the 2WD truck community due to its spotty/questionable street performance characteristics; whereas, the present invention is ideally suited for the 4WD truck community due to its utility for the street and promising off-road performance characteristics.
The present invention furnishes a suspension system that is structurally different from, yet functionally the same as, a triangulated 4-link suspension system. The triangulated 4-link suspension system is considered state of the art and utilized exclusively by customized, purpose-built off-road vehicles.
The present invention also furnishes a suspension system that:
is specifically designed to NOT interfere with other components (e.g.; engine, oil pan, gas tank, exhaust) on the vehicle and therefore is suitable for use on street driven/“non-lifted” solid axle 4WD vehicles;
is in principle one of the best articulating suspension systems available to the 4WD enthusiast;
is intended for front solid axle vehicles thereby eliminating the Panhard bar, and implicitly the incidence of “Death Wobble”;
is in principle superior to the suspension systems used by manufacturers of front and rear solid axle 4WD vehicles; e.g., Ford, Dodge Ram, Jeep, and Land Rover.
is equally adaptable to the front and rear solid axles in a 4WD vehicle.
is in particular easily adaptable to the front and rear solid axles comprised of link-style suspension systems such as those utilized by Jeep.
distributes the loads seen by the axle under hard acceleration and hard braking throughout the frame better than other link-style suspension systems, including triangulated 4-link suspension systems.
is constructed with adjustable brackets that contain a plurality of mounting points; and, with links whose lengths are adjustable and whose joints are flexible. Such adjustability permits the suspension installer to tune the suspension system for a variety of terrain and vehicle types.
Referring to
The front suspension system involves a front axle that is connected to the frame 10 with brackets 16, 17, 18, and 19 and links 13 and 14 where suspension damping is provided by a set of coil springs 20 and shock absorbers 21.
The front axle truss 15 is attached partway to the front differential housing 11 and partway to the front axle tube 12 thereby locating the front axle truss 15 in the center of the front axle. A pair of brackets 16 are attached to the top of the front axle truss 15 such that considering the brackets 16 as a single unit locates them at the center of the front axle truss 15 and thereto the center of the front axle. Brackets 17 are attached to the right and left sides of the frame 10 in front of the front axle. Brackets 18 are attached to the right and left sides of the front axle near the ends and at the bottom of the axle tube 12. Brackets 19 are attached to the right and left sides of the frame 10 behind the front axle. Brackets 17 and 19 have selectable connection locations 30 such that varying the connection point varies the load transfer distribution to the frame 10. This variance allows the suspension installer to tune the front suspension for specific characteristics.
Link 13 is connected to bracket 16 on one end and to bracket 17 on the other end, thereby adopting a diagonal geometry above and in front of the front axle and centrally locating the front axle beneath the vehicle at all times. Link 14 is connected to bracket 18 on one end and bracket 19 on the other end, thereby adopting a diagonal geometry below and behind the front axle and therefore reducing the effects of roll steer as the front suspension cycles up and down.
The rear suspension system involves a rear axle that is connected to the frame 10 with brackets 26, 27, 28, and 29 and links 24 and 25 where suspension damping is provided by a set of coil springs 20 and shock absorbers 21.
A pair of brackets 26 are arranged on the top of the rear differential housing 22 such that considering the brackets 26 as a single unit locates them at the center of the rear differential housing 22 and thereto the center of the rear axle. Brackets 27 are attached to the right and left sides of the frame 10 behind the rear axle. Brackets 28 are attached to the right and left sides of the rear axle near the ends and at the bottom of the axle tube 23. Brackets 29 are attached to the right and left sides of the frame 10 in front of the rear axle. Brackets 27 and 29 have selectable connection locations 30 such that varying the connection point varies the load transfer distribution to the frame 10. This variance allows the suspension installer to tune the rear suspension for specific characteristics.
Link 24 is connected to bracket 26 on one end and to bracket 27 on the other end, thereby adopting a diagonal geometry above and behind the rear axle and centrally locating the rear axle beneath the vehicle at all times. Link 25 is connected to bracket 28 on one end and bracket 29 on the other end, thereby adopting a diagonal geometry below and in front of the rear axle and therefore reducing the effects of roll steer as the rear suspension cycles up and down.
A. Brackets and Truss
B. Links
C. Joints
D. Fasteners
Installation of the Present Invention
While the invention has been illustrated and described as embodied in a vehicle suspension system, it is not intended to be limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled on the art without departing in any way from the scope and spirit of the present invention.
