Fluid level indicator for batteries

Claim 1

A LIQUID LEVEL INDICATOR FOR A STORAGE BATTERY, COMPRISING AN ELONGATE, FLEXIBLE GUIDE TUBE CLOSED AT ITS TOP AND OPEN AT ITS BOTTOM AND ADAPTED TO BE MOUNTED IN A STORAGE BATTERY CELL, SAID TUBE HAVING A TRANSPARENT TOP AND BEING OF REDUCED INSIDE DIAMETER AT ITS BOTTOM, AND A FLOAT MOUNTED IN SAID TUBE AND EXTENDING THROUGH THE OPEN BOTTOM THEREOF TO FLOAT AXIALLY THEREIN, SAID FLOAT HAVING ON ITS OUTSIDE SURFACE A PLURALITY OF ANGULARLYSPACED, LONGITUDINALLY-EXTENDING RIBS WHICH PROJECT RADIALLY OUTWARDLY FROM ITS OUTSIDE SURFACE, AT LEAST CERTAIN OF SAID RIBS ADJACENT THE TOP OF SAID FLOAT HAVING THEREON FURTHER RADIAL PROJECTIONS ADAPTED TO ENGAGE WITH THE REDUCED INTERNAL DIAMETER PORTION OF SAID TUBE TO PREVENT SAID FLOAT FROM DROPPING OUT OF THE BOTTOM OF SAID TUBE WHEN THE INDICATOR IS REMOVED FROM A BATTERY, SAID FLOAT BEING OF A WEIGHT AND LENGTH SUCH THAT WHEN THE INDICATOR IS MOUNTED IN A NORMALLY CHARGED BATTERY CELL THE LENGTH OF THE PORTION OF SAID FLOAT FROM ITS DRAFT LINE TO ITS TOP WHEN FLOATING IN THE LIQUID OF THE CELL WILL BE SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN THE UNDERSIDE OF SAID TUBE TOP AND THE BOTTOM OF SAID TUBE, AND SAID FLOAT HAVING A PLURALITY OF UPWARDLY-PROJECTING BOSSES ON ITS TOP TO ENGAGE THE UNDERSIDE OF THE TOP OF SAID TUBE WHEN THE LEVEL OF THE LIQUID IN THE CELL IS NORMAL, THEREBY TO REDUCE THE AREA OF CONTACT OF THE FLOAT WITH THE TOP OF THE CELL, SAID TUBE HAVING VENT HOLES INTERMEDIATE ITS ENDS AND IN ITS TOP.