Electronic weighing scales

A weighing scales comprising a normally laterally and torsionally stable elongate vertical load-supporting and force-conducting rod with an elongate upper reaction portion, an elongate lower working portion and an elongate central tension portion, said tension portion is less in cross-sectional extent than and extends between the reaction and working portions;

• a plurality of resistance-type strain gauges fixed to the tension portion in predetermined spaced relationship thereon and relative to each other;
• an elongate vertical housing with upper, central and lower portions is engaged about the rod between the upper and lower terminal end portions thereof;
• anchoring means secures the reaction portion of the rod in and with the upper end portion of the housing with the tension and working portions of the rod extending through and depending from the central and lower portions of the housing with free working clearances, a window opening in the housing;
• a circuit board mounted within the housing and carrying an electric digital display device visible through the window and a bridge circuit with a signal output connected with the digital display device and in which the strain gauges on the rod are connected, a variable resistance device with a manually engageable operating part accessible at the exterior of and carried by the housing and connected in the circuit and operating to selectively null an output signal from the circuit to the display device, a power supply battery mounted in the housing and connected with a power input of the circuit.