Lubrication of refrigeration compressors

Claim 1

IN A REFRIGERANT COMPRESSOR OF THE TYPE HAVING A GENERALLY HORIZONTALLY DISPOSED CYLINDER AND A PISTON RECIPROCABLY MOUNTED IN THE CYLINDER, A GENERALLY VERTICALLY EXTENDING DRIVE SHAFT HAVING UPPER AND LOWER CONCENTRIC PORTIONS AND AN INTERMEDIATE ECCENTRIC PORTION ALIGNED WITH THE PISTON, A CONNECTING ROD CONNECTED TO SAID ECCENTRIC PORTION AT ONE END, A WRIST PIN CONNECTING THE OTHER END OF THE CONNECTING ROD WITH THE PISTON, THE LOWER END OF SAID SHAFT BEING FORMED WITH A VERTICAL DUCT OFFSET FROM THE AXIS OF ROTATION OF THE SHAFT, MEANS RESPONSIVE TO THE CENTRIFUGAL ACTION OF THE ROTATING SHAFT AND FORMING A PUMP FOR CONDUCTING OIL UPWARDLY THROUGH SAID VERTICAL DUCT, SAID VERTICAL DUCT TERMINATING AT SAID ECCENTRIC PORTION, SAID ECCENTRIC PORTION BEING FORMED WITH A LATERAL DUCT EXTENDING FROM SAID VERTICAL DUCT TO THE PERIPHERY OF SAID ECCENTRIC PORTION, AN OIL PASSAGEWAY IN SAID CONNECTING ROD EXTENDING FROM SAID ECCENTRIC PORTION TO THE WRIST PIN AND MEANS FORMING AN OIL RESERVOIR AROUND THE LOWER END OF SAID SHAFT AND BELOW SAID LATERAL DUCT WHEREBY UPON ROTATION OF THE SHAFT, THE OIL FLOWING INTO SAID LATERAL DUCT IS FORCED CENTRIFUGALLY INTO THE OIL PASSAGEWAY IN THE CONNECTING ROD, THE IMPROVEMENT WHICH COMPRISES A VENT PASSAGEWAY IN SAID ECCENTRIC PORTION EXTENDING FROM SAID LATERAL DUCT UPWARDLY TO THE PERIPHERY OF THE SHAFT AT AN UNCOVERED PORTION ABOVE THE CONNECTING ROD WHEREBY REFRIGERANT VAPOR IN SAID VERTICAL DUCT AND LATERAL DUCT MAY ESCAPE FREELY AT ALL TIMES THEREFROM, SAID WRIST PIN BEING PROVIDED WITH OPENINGS COMMUNICATING WITH THE OIL PASSAGEWAY IN THE CONNECTING ROD, SAID WRIST PIN OPENINGS EXTENDING TO THE OUTER SURFACE OF THE PISTON TO DISTRIBUTE OIL THERETO, SAID PISTON BEING PROVIDED WITH APERTURES COMMUNICATING WITH SAID WRIST PIN OPENINGS AND EXTENDING FROM SAID SURFACE OF THE PISTON TO THE INTERIOR OF THE PISTON AND COMMUNICATING WITH THE SPACE ABOVE SAID OIL RESERVOIR WHEREBY REFRIGERANT VAPOR FORMED ADJACENT THE WRIST PIN MAY READILY ESCAPE THEREFROM.