In high speed applications, for instance, Indy 500 racing competitors have taken steps such as limiting the suspension travel to compensate for the behavior of independent suspension. (Staniforth, 104)
An alternative system that offers several possible advantages has been developed and patented by car engineer that is called the positive linked suspension system (PLSS), it is the product of several years of hard work and several false stars for engineering companies. Now it forms the heart of Tech-Engineering‘s kit vehicle, a Honda-powered tricycle. (Fred, 60)
The PLSS is a totally mechanical system with natural dynamic stability. In its simplest form, it consists of two stub axles, two body-mounted pivots, two shackles or links, and a leaf spring. The two axles support vehicle weight through the pivot points, which allow the axles to rotate freely. (Fred, 64) A leaf spring rigidly attached to on e axle is linked to other via the shackles. The shackles compensate for changes in spring length when it bends.
In this configuration, the vertical position, motion and load of one wheel is transmitted to the spring, which bends, and then to the other wheel. As a result, as one wheel moves up the opposite wheel tries to move up also. Another way to look at it is that as one wheel accepts load the opposite wheel give up loading trying to keep the theoretical line between the pivot points parallel to the road. (Valkenburgh, 205)
Because the system is naturally stable and does not allow rotational momentum to develop in the vehicles’ body, mechanical engineers are yet to find a case where shock absorbers would be required. Vertical disturbances are self-damped by out of phase load inputs to the leaf spring.
The spring acts as a mechanical interrupter and the rate and amplitude of the system’s response is controlled by adjusting the spring rate and the system’s geometry. Because