MX2008001332A - Reciprocating pump with electronically monitored air valve and piston - Google Patents

Abstract

An air operated pump 10 uses a magnet 14 mounted in the valve cup 16 of the air motor 18 and two reed sensors 20 mounted in the valve cover 22 to monitor the speed and position of the valve 16. A solenoid 24 is mounted on the valve cover 22 and can be commanded to extend a plunger 26 into the valve cup 16 to stop valve movement and therefore the pump from running away. A magnetoresistive sensor 34 is located in the center of the air motor 18 to precisely monitor the piston 36 position and with air valve sensors 20 provides the input necessary for precise control and diagnostics of the pump 10 and makes it suitable for metering and plural component application.

Description

ALTERNATIVE PUMP WITH AIR VALVE AND ELECTRONICALLY MONITORED PISTON TECHNICAL FIELD This application claims the benefit of US applications serial numbers 60 / 703,306, filed on July 28, 2005 and 60 / 704,290 filed on August 1, 2005.

PREVIOUS TECHNIQUE The alternative piston pumps operated with air are well known for pumping various fluids. Such pumps typically have air valves mechanically or pneumatically operated to control the flow of air to both sides of the piston. The control of such pumps has traditionally been through the monitoring and control of the resulting fluid flow rather than the pump itself. Prior art devices such as the Graco EXTREME-MIX ™ dispenser have monitored the position of the piston for control purposes.

BRIEF DESCRIPTION OF THE INVENTION It is, therefore, an object of this invention to provide a system that allows for improved monitoring and control of an alternative air motor to allow monitoring of piston position, cycle and flow rates, total cycles, runaway control and the ability to diagnose defective lower components of the air motor and the pump. The control uses a magnet mounted on the valve cap of the air motor and two blade sensors mounted on the valve cover to monitor the speed and position of the valve. A solenoid is mounted on the valve cover and can be instructed to extend a plunger towards the valve bushing to stop the movement of the shut-off valve and therefore prevent the pump from being repacked (usually caused by because the flow supply is empty.) The user interface includes an LCD and buttons to install and control the pump. The display can be alternated to display the cycle speed, flow rate (in various units), total cycles and diagnostic errors. Installation parameters may include fluid units (quarts, liters, etc.) and the runaway set point. The foil switches and magnets are positioned to detect when the air valve is in the extreme position of each stroke or in transition or both. The controller calculates the speed at which the motor is running by counting the opening and closing of the leaf switches activated by the variable positions of the air valve. The controller then compares that speed with a preprogrammed value to determine if the air motor is in a runaway condition. If that condition is present, the controller activates the solenoid avoiding the change that stops the motor. This acts to prevent spilled fluid and / or pump damage. A magnetoresistive sensor is located in the center of the air motor to accurately monitor the position of the piston. The data of this sensor together with those of the air valve sensors provide the necessary input for the precise control and diagnosis of the pump and make it suitable for measurement and application of several components. These and other objects and advantages of the invention will appear more fully from the following description made in conjunction with the accompanying drawings, wherein the similar reference characters refer to the same or similar parts throughout the various views.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cross-section of the air valve as part of the present invention representing magnets and sheet switches; Figure 2 shows a detail of the cross section of Figure 1 of the air valve as part of the present invention; Figure 3 shows a cross section (opposite to that of Figure 1) of the air valve as part of the present invention showing the solenoid; Figure 4 shows a view of a pump embodying the present invention; Figure 5 shows a detail of the user interface of the present invention; Figure 6 shows the diagnostic codes that can be obtained when detecting the air valve; and Figure 7 shows the piston and the magnetoresistive sensor.

DETAILED DESCRIPTION OF THE INVENTION In an alternative piston pump operated with air 10, the controller 12 uses a magnet 14 mounted on the cap 16 of the air motor valve 18 and two sheet sensors 20 mounted on the cover 22 of the valve to monitor the speed and the position of the valve 16. A solenoid 24 is mounted on the cover 22 of the valve and can be instructed to extend a plunger 26 towards the valve socket 16 to stop the movement of the valve and therefore prevent the pump 10 is packaged (usually, because the supply of flow is empty or the hose of another supply conduit has leakage / rupture). The user interface 28 comprises an LCD display 30 and buttons 32 for installing and controlling the pump 10. The display 30 may be alternated to display the cycle speed, flow rate (in various units), total cycles and diagnostic errors . Installation parameters may include fluid units (quarts, liters, etc.) and the runaway set point. The reed switches 20 and magnets 14 are positioned to sense when the air valve 16 is in the extreme position of each stroke or in transition or both. The controller 12 calculates the speed at which the motor 18 is running by counting the opening and closing of the leaf switches 20 activated by the variable positions of the air valve 16. The controller 12 then compares that speed with a preprogrammed value for determining if the air motor 18 is in a runaway condition. If that condition is present, the controller 12 activates the solenoid 24 preventing the change that stops the motor 18. This acts to prevent spilled fluid and / or pump damage.

A magnetoresistive sensor 34 is located in the center of the air motor 18 to accurately monitor the position of the piston 36. The data of this sensor 34 together with those of the sensors 20 of the air valve provide the necessary input for the control and precise diagnosis of the pump 10 and make it suitable for measurement and application of several components. It is considered that various changes and modifications to the control of the pump can be made without departing from the spirit and scope of the invention as defined by the following claims.

Claims (6)

NOVELTY OF THE INVENTION CLAIMS

1. - An air operated pump having an air valve with a valve bushing and a valve cover, the improvement comprising: a magnet mounted on said valve bushing of said air motor; and first and second blade sensors on the valve cover to monitor the speed and position of the valve.

2. The air operated pump according to claim 1, further characterized in that it further comprises a solenoid having a plunger and mounted on said valve cover, said solenoid is capable of extending said plunger toward said valve cap for stop the movement of the valve and therefore, prevent the pump from packing.

3. The air operated pump according to claim 1, further characterized in that it additionally comprises a user interface that monitors said blade sensors to allow the deployment of various parameters.

4. The air operated pump according to claim 3, further characterized in that said parameters may include cycle speed, flow rate, total cycles and diagnostic errors.

5. - The pump operated with air according to claim 1, further characterized in that said pump operated with air comprises a piston and further comprises a sensor for detecting the position of said piston.

6. The pump operated with air according to claim 5, further characterized in that said sensor comprises a magnetoresistive sensor.