| 摘要 |
1,032,640. Piston rings. DANA CORPORATION. Jan. 18, 1965 [April 27, 1964], No. 2205/65. Heading F2T. A spacer-expander ring 20 for a piston-ring particularly an oil ring, assembly is coated with a layer of polytetrafluorethylene 40 preferably of a thickness between 0À0003 and 0À0008 inch. Split rings 18 are urged both radially into contact with the cylinder 16 and axially against the walls 36 of the groove 12 in the piston 14 by the spacer-expander ring 20 which is split and comprises upper and lower spring members 24, 26 interconnected at their outer peripheries by spaced struts 28 and having inclined shoulders 32 that contact the inner peripheries of the rings 18. Oil removed from the cylinder by the rings 18 flows between the struts 28 and is drained through an opening 30 in the piston. The layer of polytetrafluoroethylene reduces friction between the rings 18 and the spacer-expander ring 20 and inhibits the formation of carbonaceous deposits on the latter. Reference has been directed by the Comptroller to Specification 881,932. |
