Four-tube hydraulic scale with zeroing feature

Claim 1

A WEIGHING MACHINE COMPRISING A WEIGHING PLATFORM; A PLURALITY OF DEFORMABLE PRESSURE-GENERATING FLUID CONTAINERS DISPOSED BENEATH THE PLATFORM; THE PLATFORM RESTING ON THE CONTAINERS; U-TUBES PARTIALLY FILLED WITH MERCURY; A CALIBRATED LIQUID-CONTAINING VERTICAL TUBE; AN ADJUSTING VALVE; ONE END OF EACH U-TUBE BEING CONNECTED TO A SEPARATE CONTAINER AND THE OTHER END OF EACH U-TUBE BEING CONNECTED VIA SAID ADJUSTING VALVE TO SAID CALIBRATED LIQUID-CONTAINING VERTICAL TUBE; THE ADJUSTING VALVE COMPRISING A BLOCK MEMBER HAVING A RECESS PROVIDED IN ONE SURFACE THEREOF; A FLEXIBLE DIAPHRAGM IN ENGAGEMENT WITH SAID ONE SURFACE OF THE BLOCK MEMBER TO FORM A LIQUID CHAMBER THEREBETWEEN; SEPARATE LIQUID INLET BORES TO THE CHAMBER PROVIDED WITHIN THE BLOCK MEMBER AND IN COMMUNICATION EACH WITH A SEPARATE ONE OF SAID OTHER ENDS OF THE U-TUBES; A SINGLE LIQUID OUTLET BORE FROM THE CHAMBER WITHIN THE BLOCK MEMBER AND IN COMMUNICATION WITH THE CALIBRATED VERTICAL TUBE WHEREBY FLEXING ADJUSTMENT OF THE FLEXIBLE DIAPHRAGM INTO AND OUT OF THE CHAMBER VARIES THE VOLUME OF THE LIQUID CHAMBER TO ADJUST TO ZERO THE HEIGHT OF THE LIQUID IN THE CALIBRATED VERTICAL TUBE, THE WEIGHT OF AN ARTICLE OR ARTICLES PLACED ON THE PLATFORM EXERTING PRESSURE ON THE FLUID IN THE PRESSURE GENERATING FLUID CONTAINERS SUCH THAT THE MERCURY IN THE U-TUBES IS DISPLACED, WITH THE TOTAL DISPLACEMENT OF THE MERCURY BEING INDICATED ON THE CALIBRATED VERTICAL TUBE AS A RISE ABOVE ZERO OF THE LIQUID THEREIN, DENOTING THE WEIGHT OF THE ARTICLE OR ARTICLES ON THE PLATFORM.