Patent ID: 9677549
Date: 2017-06-13
CPC Classifications: F04B

Claim:
1. An air operated reciprocating piston pump comprising: an air motor for driving the pump, the air motor having a piston; a sensor comprising a linear transducer that monitors position of the piston in the air motor; an air valve that controls flow of air to opposite sides of the piston of the air motor, a magnet mounted in said valve cup of said air motor; first and second reed sensors mounted in the valve cover to monitor the speed and position of the valve, wherein the first and second reed sensors and the magnet are located so as to detect when the air valve is at an extreme position of each stroke or in transition between extreme positions, or both; a solenoid having a plunger and being mounted on said valve cover, said solenoid being capable of extending said plunger into said valve cup to stop valve movement and therefore the pump from running away; a controller that calculates a rate at which the air motor is running based on opening and closing of the first and second reed sensors activated by varying positions of the air valve, determines whether the air motor is in a runaway condition, and activates the solenoid to extend the plunger into the valve cup to stop valve movement and thereby stop the air motor when the controller determines that a runaway condition is present.