Abstract: A scale testing vehicle for transporting certified weights and depositing them on the platform of truck scales, the vehicle body having a pair of rails supported above a truck bed carrying the weights and having a trolley carried by the rails for movement fore and aft. A cable is looped over pulleys at each end of the rail and is attached at one end to the trolley with its free end passing over a sheave on the trolley and supporting a bar having hooks for attaching to the weights. One of the pulleys may be moved to change the cable loop length, thereby raising or lowering the weights supported on the hooks. The bar has a counterweight which pivots the hooks when the weights are not supported therefrom so that the hooks clear the weights when moved horizontally. Hydraulic output from a truck engine driven pump is used to traverse the trolley as well as to raise and lower the weights so that transfer between truck and scale may be expeditiously accomplished.

Abstract: A vehicle with a vertically adjustable auxiliary axle and having its center of gravity located behind the auxiliary axle so that when said axle is moved down to a testing position where its wheels engage the ground, the front wheels of the vehicle are raised off the ground and the entire vehicle weight is supported by the rear wheels and the auxiliary wheels. When the auxiliary axle is in a testing position, the distance between the outer edges of the contact surfaces of the auxiliary and rear wheels is on the order of but not greater than 10 feet. The vehicle may be rolled over a scale platform while in the testing position so that a known weight is applied in an infinite number of 10 foot sections. The scale may be calibrated to accurately reflect the known weight under all different applications of that weight.