The braking distance and time required to stop a moving vehicle are related to the kinetic energy of the vehicle at the moment the brakes are first applied; the brakes being simply devices for converting the kinetic energy into heat. The kinetic energy is a function of the vehicle mass and the square of the vehicle velocity. Since velocity is squared, a doubling of the vehicle speed results in a four-fold increase in the energy that must be converted to heat by the brakes, holding the mass constant, while doubling the mass, holding the velocity constant, will merely double the kinetic energy. Obviously then, it will require a greater time, and hence a greater distance, to bring a vehicle to a stop, everything else being equal, if the vehicle is traveling at a greater speed; the important factor being that the braking distance to speed relationship is not a straight line but a curve of the second order.
Log skidders, because of their mass and the rough terrain over which they customarily operate, are usually provided with some form of hydraulic assist for the steering. An engine failure or other loss of hydraulic fluid pressure results in loss of the hydraulic assist for the steering. In order to compensate for this possibility, log skidders have been provided with various forms of auxiliary steering. Since most log skidders have transmissions with speed ratios in both forward and reverse which are substantially equal, it is possible to attain top speeds in either direction which are substantially equal and relatively high. With speed being the more important criterion in determining braking distance, it is necessary to provide auxiliary steering in such vehicles in either direction. However, if the vehicle has a transmission ratio in one direction, preferrably reverse as a practical matter, which limits the top speed attainable in that direction to a relatively low speed, the vehicle can be stopped in a short distance without the need for an auxiliary steering arrangement that provides steering assist in that direction.
It is, therefore, an object of this invention to provide an auxiliary steering system which is simple, relatively inexpensive and capable of installation in a vehicle with relative ease.
It is also an object of this invention to provide a vehicle having high top speeds in only one direction with such an auxiliary steering system when the vehicle is traveling in that direction.
These and other objects of the present invention, and many of the attendent advantages thereof, will become more readily apparent upon a perusal of the following description of a perferred embodiment and the accompanying drawings, wherein;