Fixed displacement pump

The present application relates generally to beverage dispenser components and more particularly relates to a fixed displacement solenoid pump for use within a beverage dispenser or in other types of fluid transport devices and systems.

Variable displacement solenoid pumps are widely used in beverage dispensers and in the beverage industry in general. These pumps generally have a hydraulic flow rate depending on the fluid to be pumped, the working pressure, and the electromagnetic temperature. The working pressure may vary according to the resistance opposed to the pumping system. These pumps are in wide use in the industry because they generally have small dimensions, low price, and low operating costs.

The beverage industry, however, is moving towards the use of ever smaller individual beverage components. For example, a beverage may include a number of micro-ingredients, a number of macro-ingredients, and a number of diluents. The micro-ingredients may have a reconstitution ratio of about ten (10) to one (1) or more, and in many cases, even one hundred (100) to one (1) or more. See, e.g., commonly owned U.S. Patent Publication No. 2007/0205221 entitled “Beverage Dispensing System” and U.S. Patent Publication No. 2007/0205220 entitled “Juice Dispensing System.”

As a result of the use of these ever smaller components, there is a desire to meter accurately these small amounts of fluids in a consistent and repeatable fashion. Likewise, these fluids preferably should be metered in a relatively inexpensive pump that may be easy to install, use, and repair.

The present application thus provides a fixed displacement pump. The fixed displacement pump may include a chamber, a piston positioned within the chamber, and a collar positioned within the chamber to as to limit movement of the piston within the chamber.

The fixed displacement pump further may include an electric coil surrounding the chamber and a piston spring attached to the piston. The collar may be positioned outside of the piston spring or inside of the piston spring. The collar may integral with the chamber or nonintegral with the chamber. The collar may include a predetermined length. The fixed displacement pump further may include a number of collars with varying lengths.

The application further describes a method of retrofitting a variable displacement pump having a chamber and a piston therein. The method may include positioning a collar within the chamber, limiting the extent of a stroke of the piston within the chamber by the collar, and operating the pump as a fixed displacement pump.

The method further may include determining a desired length of the stroke of the piston. The step of positioning the collar may include positioning a collar of a predetermined length.

The application further describes a fixed displacement solenoid pump. The fixed displacement solenoid pump may include a chamber, a piston positioned within the chamber, a piston spring attached to the piston, and a collar positioned within the chamber to as to limit movement of the piston within the chamber.

The fixed displacement solenoid pump further may include an electric coil surrounding the chamber. The collar may be positioned outside of the piston spring or inside of the piston spring. The collar may be integral with the chamber or nonintegral with the chamber. The collar may include a predetermined length. The fixed displacement pump further may include a number of collars with varying lengths.

These and other features of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.