Proportioning system

Claim 1

A PROPORTIONING SYSTEM PARTICULARLY ADAPTABLE FOR FEEDING AN EPOXY RESIN AND HARDENER THEREFOR IN ACCURATELY METERED, VOLUMETRIC PROPORTIONS TO A MIXING AND SPRAYING HEAD IN WHICH THE EPOXY RESIN AND HARDENER ARE ADMIXED AND FROM WHICH THE ADMIXED MATERIALS ARE DISCHARGED COMPRISING SEPARATE CONTAINERS FOR SAID EPOXY RESIN AND FOR SAID HARDENER, A POSITIVE DISPLACEMENT, VOLUMETRIC METERING PUMP CONNECTED TO EACH CONTAINER THROUGH A CONDUIT, MEANS FOR FEEDING EACH MATERIAL FROM ITS CONTAINER TO THE METERING PUMP CONNECTED THERETO, MEANS FOR OPERATING EACH OR SAID METERING PUMPS, SAID METERING PUMPS OPERATING AT A DISCHARGE PRESSURE SUBSTANTIALLY EQUAL TO THEIR INTAKE PRESSURE WHEREBY EACH OF SAID MATERIALS IS FED THROUGH ITS METERING PUMP UNDER SUBSTANTIALLY ZERO PRESSURE DIFFERENTIAL AND TO A MIXING AND SPRAYING HEAD IN ACCURATELY METERED, VOLUMETRIC QUANTITIES, AND SENSING MEANS, MOUNTED AT EACH METERING PUMP AND CONNECTED IN SERIES TO EACH OTHER AND TO THE MEANS WHICH OPERATES EACH OF SAID METERING PUMPS, FOR SENSING THE DISCHARGE PRESSURE OF SAID METERING PUMPS AND IN RESPONSE THERETO, STARTING THE OPERATION OF SAID METERING PUMPS WHEN THE DISCHARGE PRESSURE THEREOF IN LESS THAN THE PREDETERMINED DISCHARGE PRESSURE AND STOPPING THE OPERATION OF SAID METERING PUMPS WHEN THE DISCHARGE PRESSURE THEREOF IS GREATER THAN THE PREDETERMINED DISCHARGE PRESSURE.