Snap-on Inc.

Snap-on Technologies, Inc.

Roger L Husarik

J Steven Martin

Dean P Pfefferle

A refrigerant recovery and/or recycling system includes fluid flow control mechanism controlling the flow of refrigerant between a refrigerant containing structure and an associated refrigeration unit, under the control of a microprocessor-based control circuit. The system has a text-based display screen and selective input keys including software-definable keys respectively associated with different regions of the display screen and respectively associated therewith by indicia on the screen bezel. Memories are coupled to the control circuit for cooperation therewith to control the display of messages on the display screen and for defining functions performed by the software-definable keys in accordance with the corresponding messages displayed on the display screen.

Low-cost user interface for refrigerant recycling machine

A refrigerant recycling system includes a recycled refrigerant tank for storing recycled refrigerant, and first and second valves connected in series between the recycled refrigerant tank and atmosphere. In purging non-condensables from the recycled refrigerant tank to atmosphere, a programmed microcontroller holds the first valve open for exposing the pressure transducer to the pressure in the recycled refrigerant tank, and opens the second valve when the measured pressure exceeds a predetermined pressure for purging non-condensables to atmosphere, holding the second valve open until the measured pressure drops below the predetermined pressure. The pressure checking and purging steps are repeated after a short period, as often as necessary until the measured pressure is less than or equal to the predetermined pressure while the second valve is closed and then, after a longer delay, the system goes through one more pressure check and, if necessary, purging operation.

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Bartlett, IL, United States of America

Roger L Husarik