Self-service refrigerated display case

Claim 1

A SELF SERVICE REFRIGERATED DISPLAY CASE HAVING A BASE, A TOP, A MEMBER EXTENDING VERTICALLY FROM SAID BASE TO SAID TOP, AIR SUPPLY AND AIR RETURN DUCTS IN SAID VERTICALLY EXTENDING MEMBER, MEANS FOR FORCING AIR THROUGH SAID AIR SUPPLY DUCT AND FOR DRAWING AIR INTO SAID AIR RETURN DUCT, A PLURALITY OF HOLLOW SHELVES ARRANGED IN VERTICALLY SPACED RELATION WITHIN SAID CASE AND EACH COMMUNICATING WITH SAID AIR SUPPLY DUCT, THE VERTICALLY EXTENDING MEMBER HAVING OPENINGS THEREIN COMMUNICATING WITH THE SPACE BETWEEN SAID SHELVES AND SAID AIR RETURN DUCT, SAID SHELVES HAVING OPENINGS THEREIN ADJACENT THE OUTER EDGES OF THE SHELVES, AND MEANS FOR REFRIGERATING THE AIR FORCED THROUGH THE AIR SUPPLY DUCT TO EACH SHELF TO PRODUCE AN INDEPENDENT AIR CURTAIN ADJACENT THE FRONT OF EACH SHELF, THE AIR FROM SAID AIR CURTAIN FLOWING REARWARDLY THROUGH THE SPACE BETWEEN SAID SHELVES FROM THE FRONT TO THE REAR OF THE SHELVES SO AS TO BE DRAWN THROUGH THE OPENINGS IN THE VERTICALLY EXTENDING MEMBER TO SAID AIR RETURN DUCT.