Fluidic leak detector

Claim 1

A fluidic detector for testing bottles for leaks, said detector comprising: A. a sensor adapted to produce a start signal indicative of the presence of a bottle at a test position; B. a retractable head responsive to said start signal to engage the mouth of the bottle and to supply a fluid thereto for a predetermined period, causing the inteRnal pressure of the bottle to rise to an extent determined by its condition, the level of internal pressure thereafter decaying in a defective bottle having a leak; C. a fluidic logic circuit responsive to the internal pressure in said bottle and adapted to compare the level thereof with reference values to determine whether the bottle is acceptable and, in the event there is a decaying level as a result of a leak which renders the bottle defective, to produce a reject signal, said logic circuit including a comparator to compare the level of the internal pressure with a pre-set reference value to determine whether this level rises above the pre-set value during a bottle-filling phase, and to compare the level of internal pressure with a test reference value to determine whether the level decays below said test value during a subsequent test phase, said reject signal being produced in the event the level fails to rise above the pre-set value or decays below the test value; and D. means responsive to said reject signal to eject the defective bottle after the head is retracted.