Soil penetration and shear measuring instrument

Abstract

Abstract IN THIS INSTRUMENT, A SINKAGE PLATE ATTACHED TO A VERTICAL SHAFT IS SELECTIVELY PUSHED STRAIGHT DOWNWARD FOR STRAIGH PENETRATION OR IN A SPIRAL PAT FOR SHEAR PENETRATION BY MEANS OF A ROTARY NUT THREADEDLY ENGAGING A ROTARY FAST-THREAD SCREW SHAFT WHICH IS SELECTIVELY CONNECTED OR DISCONNECTED FROM THE NUT FOR UNITARY OR RELATIVE MOTION THEREBETWEEN BY MEANS OF A SELECTIVE CLUTCH. THE SCREW SHAFT AT ITS UPPER END IS ENGAGED BY THE LOWER END OF A NON-ROTATABLE SHAFT THROUGH A THRUST BEARING. THE NON-ROTATABLE SHAFT IS IN TURN ENGAGED BY AND SUBJECTED TO THE THRUST OF A CALIBRATED COMPRESSION LOADING SPRING, THE UPPER END OF WHICH IS GIVEN AN INITIAL LOADING BY MANUALLY MOVING DOWNWARD AN UPPER SPRING ABUTMENT STRUCTURE CARRYING A ROTARY RECORDING DRUM. THE DOWNWARD MOTION OF THE NON-RTATABLE SHAFT IS TRANSMITTED THROUGH A CARRIAGE AND MOTION-MULTIPLYING MECHANISM TO A SCRIBER WHICH RECORTDS THE MOTION ON A CHART ATTACHED TO THE ROTARY DRUM. THE RESULTING GRAPH SHOWS THE RESISTANCE OFFERED BY THE GROUND TO THE PENETRATION OF THE SINKAGE PLATE EITHER DIRECT OR IN SHEAR, DEPENDING ON WHEATHER THE SCREW SHAFT IS LOCKED BY A CLUTCH AGAINST ROTATION OR IS UNLOCKED AND FREE TO ROTATE. THE RECORDING DRUM IS SPRING-WOUND AND ITS ROTATION IS CONTROLLED BY A FLEXIBLE CABLE-WOUND AROUND A PORTION OF THE DRUM AND GUIDED DOWNWARD OVER A PULLEY TO AN ANCHORAGE ON THE SUBSTANTIALLY IMMOVABLE BASE STRUCTURE OF THE INSTRUMENT.

Inventors

• 👤 Edward M Hawes

Bibliographic Details