Manually operable implement for injecting anhydrous ammonia and other liquid fertilizrs into the soil

Claim 1

APPARATUS FOR DISPENSING A MEASURED CHARGE OF LIQUID FROM A PRESSURIZED SOURCE THEREOF TO A LOWER PRESSURE COMPRISING: CYLINDER MEANS HAVING A LIQUID INLET PASSAGE ADAPTED FOR CONNECTION TO A PRESSURIZED SOURCE OF LIQUID, PISTON MEANS SLIDABLE WITHIN SAID CYLINDER MEANS AND DEFINING THEREWITHIN A MEASURING CHAMBER AND A POWER CHAMBER SAID POWER CHAMBER BEING CONSTRUCTED AND ARRANGED FOR CONSTANT COMMUNICATION WITH SAID INLET PASSAGE TO DEVELOP A PRESSURE FORCE ON SAID PISTON MEANS TO MOVE THE LATTER IN A DISPENSING DIRECTION AND DIMINISH THE SIZE OF SAID MEASURING CHAMBER; DIFFERENTIAL AREA MEANS ASSOCIATED WITH SAID PISTON MEANS FOR OVERCOMING SAID PRESSURE FORCE AND FOR MOVING SAID PISTON MEANS IN A FILLING DIRECTION TO INCREASE THE SIZE OF SAID MEASURING CHAMBER WHEN THE LATTER IS CONNECTED TO THE PRESSURIZED SOURCE OF LIQUID; DISCHARGE CONDUIT MEANS; MANUALLY OPERABLE VALVE MEANS MOUNTED TO SAID CYLINDER MEANS FOR SELECTIVE-