Low tension piston rings and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9494233-B2
Application number	US-201615002753-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Mar 14, 2013
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

The invention provides a low tension piston ring having a finished outer diameter and negligible tangential tension. The method includes the steps of machining a stock bar to an initial outer diameter slightly greater than the finished outer diameter of the piston ring, finishing the initial outer diameter of the stock bar to a rounded profile having a nominal diameter equal to the finished outer diameter, and machining the stock bar to the preferred cross-section. Dykes-type piston rings can have keystone or semi-keystone shaped cross-sections. The method continues by detaching the piston ring from the stock bar using a parting tool in response to completing all tension inducing operations including the steps recited above. The method continues with the steps of lapping the piston ring to a final longitudinal thickness and cutting the piston ring longitudinally to form a final gap.

First claim

What is claimed is:

1. A dykes-type piston ring comprising;
an annular ring body presenting a generally L-shaped cross-section with a lip section that extends longitudinally relative to said ring body and a tail section with a pair of sides that extends radially inwardly from said lip section,
said annular ring body having a pair of lateral faces defining a final gap therebetween, and
said annular ring body having a measurable tangential tension ranging from zero to 25 Newtons in a free and uncompressed state.

2. A dykes type piston ring as set forth in claim 1 wherein said final gap has a gap width measurable between said lateral faces ranging from zero to 0.4 millimeters when said annular ring body is in said free and uncompressed state.

3. A dykes type piston ring as set forth in claim 2 wherein said gap width ranges from zero to 0.1 millimeters when said annular ring body is in said free and uncompressed state.

4. A dykes type piston ring as set forth in claim 1 wherein said pair of sides of said tail section each tapper inwardly to define a keystone shaped cross-section.

5. A dykes type piston ring as set forth in claim 1 wherein one of said pair of sides of said tail section tappers inwardly to define a semi-keystone shaped cross-section.

6. A dykes type piston ring as set forth in claim 1 wherein said annular ring body includes an outer circumferential surface having a predetermined profile of arcuate shape.

Assignees

• Federal Mogul Corp
• Federal Mogul Corp

Inventors

• Salenbien Gregory
• Azevedo Miguel
• Belford Matthew

Classifications

• F16J9/14

  Joint-closures · CPC title

• B23P15/06

  piston rings from one piece · CPC title

• Y10T29/49284

  including machining or angular cutting · CPC title

• B23P15/065

  from metal strip · CPC title

• F16J9/02 Primary

  L-section rings · CPC title