INSTRUMENT FOR CHECKING SMOOTHNESS OF ROAD PAVEMENTS Russian patent published in 1999 - IPC

FIELD: road building machinery and equipment. SUBSTANCE: 3-m long bar of instrument is lowered to pavement surface by means of hydraulic system for measuring pavement surface irregularities at 5 points. Also provided are contactless movement sensors and hydraulic measuring system which is made up of Measuring and totaling hydraulic cylinders. Measuring system ensures Required transmission ratio between measuring bar and roll of sensor. Higher productivity in checking and processing of measuring results is achieved due to introduction of electronic unit which controls successive lowering of measuring bar, calculates values of clearances under bar and indicates results of measurements. Maximal values of clearances can be preset in digital form by means of button-type switches. Instrument has bogie with frame which carries measuring bar and bar lowering hydraulic cylinder. Bar contains measuring hydraulic cylinders with measuring rods and electrically controlled valves. Measuring hydraulic cylinders are connected with totaling hydraulic cylinder. Movement of piston of totaling hydraulic cylinder is transmitted through toothed bar and gear to sensor roll. Totaling cylinder is connected with main hydraulic cylinder and reservoir. Pressure in main hydraulic cylinder is created by operator by pressing on control lever. This creates pressure in bar lowering hydraulic cylinder and totaling hydraulic cylinder. This lowers measuring bar onto road pavement together with successive lowering of measuring rods. Electronic unit indicates values of clearances under measuring bar. Application of aforesaid embodiment of instrument gives more accurate results of measurements. EFFECT: higher efficiency. 3 dwg