Safety-load control of parallelogram type of load cell

Claim 1

A FORCE MEASURING DEVICE COMPRISING, IN COMBINATION, A PAIR OF SUBSTANTIALLY PARALLEL BEAMS HAVING FLEXURE ELEMENTS AT EACH END THEREOF, RIGID SECTIONS AT BOTH ENDS OF SAID BEAMS, THE FLEXURE ELEMENTS AT ONE OF THE CORRESPONDING ENDS OF THE BEAMS BEING CONNECTED TO ONE OF SAID RIGID SECTIONS AND THE FLEXURE ELEMENTS AT THE OTHER CORRESPONDING ENDS OF THE BEAMS BEING CONNECTED TO THE OTHER RIGID SECTION, LOAD TRANSMITTING CANTILEVER MEMBERS POSITIONED ABOVE AND BELOW SAID BEAMS AND CONNECTED RESPECTIVELY AT ONE OF THEIR ENDS TO SAID RIGID SECTIONS WHILE THEIR OTHER FREE ENDS HAVE PORTIONS DISPOSED RESPECTIVELY ADJACENT TO PORTIONS OF SAID RIGID SECTIONS WHEREBY THE BEAMS AND CANTILEVER MEMBERS ARE IN SUBSTANTIALLY SUPERIMPOSED RELATION SO THAT A LOAD FORCE TO BE MEASURED IS APPLIED TO EACH OF SAID CANTILEVERS SUBSTANTIALLY NORMAL TO THE DIRECTION OF THE SUPERIMPOSED RELATION, AND LOAD LIMITING MEANS DISPOSED BETWEEN EACH FREE END OF THE LOAD TRANSMITTING CANTILEVER MEMBERS AND THE RIGID SECTIONS ADJACENT THERETO, THEREBY TO PREVENT SAID BEAMS FROM BEING STRAINED BEYOND A PREDETERMINED LOAD, SAID COMBINATION BEING FURTHER CHARACTERIZED IN THAT THE LOAD LIMITING MEANS INCLUDES TRANSVERSE SLOTS IN THE RIGID END SECTIONS, AND A SAFETY ELEMENT SECURED TO THE END OF THE LOAD TRANSMITTING CANTILEVER MEMBERS AND PROVIDED WITH A SHOULDERED PORTION EXTENDING INTO SAID SLOT IN NORMALLY SPACED RELATION THERETO, WHEREBY SAID SHOULDER PORTION ENGAGES A SURFACE OF THE SLOT UPON OCCURRENCE OF SAID PREDETERMINED RELATIVE MOVEMENT UNDER LOAD.