Pneumatic Pump

Abstract

A pneumatic pump can be controlled using a microcontroller and a solenoid thereby eliminating mechanical linkages which can extend the periods between down time of the pneumatic pump.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a pneumatic pump. The invention particularly relates to a pneumatic pump employing an electronic controller.

2. Background of the Art

Pneumatic pumps are conventionally controlled using mechanical actuators. For example, a mechanically actuated 2-way air valve typically employs a lever arm connected to the pump piston shaft moves as the pump makes a suction and a discharge stroke. The linkages are set such that at the maximum stroke point, the linkage changes the air valve position to reverse the air flow to the diaphragm that drives the piston. This initiates the suction (or retraction) stroke. In a similar fashion, at the end of the suction stroke; the linkage again switches the air valve and starts the discharge (injection) stroke again. This process is repeated for every stroke and actually controls both the suction & discharge strokes of the pump. This type of controller is known in the industry as a “micro switch” pneumatic controller.

Due to the inherent problems associated with mechanical wear, such pumps often fail It is usually due to the mechanical linkages wearing out.

SUMMARY OF THE INVENTION

In one aspect, the invention is a pneumatic pump wherein the stroke of the pump is controlled electronically rather than mechanically.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail embodiments thereof with reference to the attached drawings in which:

FIG. 1 is an illustration of a prior art mechanically controlled pneumatic pump;

FIG. 2 is an illustration of a micro-programmable logic controller; and

FIG. 3 is an illustration of a 3-way solenoid air valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the invention is a pneumatic pump employing a microcontroller and a solenoid to actuate the piston of the pump. The microcontroller and solenoid replace the prior art mechanical linkages to control the movement of the pump's piston.

The firmware program stored on the micro-controller that will control the suction and discharge stroke length timing based on parameters set for each specific pump type or model. Since this completely eliminates the mechanical linkage part of the prior art pneumatic pump micro switch controller, it may eliminate pump failures due to breakages of this linkage mechanism. This extends the mean time between failure (MTBF) for this style of pneumatically powered chemical pump dramatically.

In another embodiment, the pneumatic pump may be employed with additional elements to control the pump. For example, the pump may be employed with one or more sensors to control pump rates.

Generally, the solenoid is a three way (3/2) solenoid, but others may also be used. For example, in addition to a 3/2; a 2/2, 5/2, or even a 5/3 solenoid may also be employed for controlling pneumatic pumps.

In still another embodiment, the microcontrollers used with the applications are not specialized to any particular application. This is an advantage where often such controllers are specialized and thus inflexible in their uses.

Claims

1. A system comprising: a pneumatic pump;a solenoid; anda microcontroller, wherein the microcontroller controls the solenoid which actuates the pneumatic pump.

2. The system of claim 1 additionally comprising a sensor which is employed in an end use application and the sensor sends a signal to the microcontroller which is then used in onboard logic to start, stop, speed up, or slow down the pneumatic pump.