US20040051252A1 - Angled gap compression rings with end relief - Google Patents
Angled gap compression rings with end relief Download PDFInfo
- Publication number
- US20040051252A1 US20040051252A1 US10/243,967 US24396702A US2004051252A1 US 20040051252 A1 US20040051252 A1 US 20040051252A1 US 24396702 A US24396702 A US 24396702A US 2004051252 A1 US2004051252 A1 US 2004051252A1
- Authority
- US
- United States
- Prior art keywords
- ring
- gap
- compression ring
- longitudinal axis
- relieved
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
- F16J9/12—Details
- F16J9/14—Joint-closures
Definitions
- This invention relates to engine piston compression rings having modified gap end configurations.
- ring joints have been used including lap joints, angle joints, seal joints, and butt joints.
- modified ring joints may still allow end butting to occur under severe conditions such as low temperature cold starting and warm up.
- the present invention provides engine piston compression rings which can minimize negative effects of ring gap end butting while optionally providing smaller ring gaps and reduced gas blowby in normal operation.
- the invention controls deflection of the ring ends by using an angled joint and a relieved ring end.
- the angled joint and an appropriately placed relief area allow the relieved ring end to deflect a substantial distance after butting of the ring ends and before the relieved end engages a wall of an associated ring groove of the piston.
- the direction of deflection is controlled by the angle and direction of the ring joint. Deflecting the relieved portion of the ring end allows additional relative ring expansion after ring end butting without increasing the ring load against the cylinder bore. Thus, harmful effects of end butting are minimized and the gap between the ring ends can be reduced, resulting in reduced blowby.
- a compression ring has a gap that forms an angle with respect to a radius drawn from a longitudinal axis. Butting of the ring ends at the gap causes one end of the ring to be deflected inward and that one end is relieved for a portion along an inner edge. The relieved portion slopes outward toward the ring end where the radial thickness of the ring is smallest. This design creates end relief, which allows the relieved end of the ring to bend into the annular piston ring groove instead of increasing ring load against the cylinder bore.
- a variation of the previously described embodiment has a slot adjacent the relieved portion that extends outward from the inner edge to promote bending of the relieved end. This slot decreases the force required during end butting to move the relieved end inward toward the piston instead of increasing ring load against the cylinder bore.
- the relieved portion is generally circumferential with a transition portion to the full ring thickness. This design creates end relief, which allows the relieved end to bend a greater distance than the previous embodiments.
- the compression ring has a gap that forms an angle with respect to the longitudinal axis of the ring. Butting of the ring ends at the gap causes one end of the ring to slide up on the angled other end so that the one end is relieved for a portion along the upper side of the ring. The relieved portion slopes downward toward the ring end where the longitudinal thickness of the ring is smallest.
- This design creates a form of end relief which allows the relieved end of the ring to slide toward the top of the annular piston ring groove instead of bending in toward the inner diameter of the ring groove like the other embodiments referred to.
- the invention is particularly useful in avoiding negative effects of ring end butting which may occur under severe low temperature cold engine starting and warm-up conditions. However, it can also reduce effects of end butting under other conditions and may be used to reduce ring gap dimensions with resulting reductions of gas blowby during normal engine running.
- FIG. 1 is a top view of a first embodiment of engine piston compression ring according to the invention
- FIG. 2 is an enlarged side view from the line 2 - 2 of FIG. 1 showing the gap portion of the ring;
- FIG. 4 is a view similar to FIG. 3 showing a modified embodiment of piston compression ring
- FIG. 7 is an enlarged fragmentary side view of the embodiment of FIG. 6.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
Description
- This invention relates to engine piston compression rings having modified gap end configurations.
- It is known in the art relating to engine piston compression rings that joints between the ring ends should allow enough space to normally avoid ring gap end butting. The traditional approach used to minimize end butting has been to increase the gap size between the ring ends. However, increasing the gap size between the ring ends increases the amount of combustion gas blowby.
- Various types of ring joints have been used including lap joints, angle joints, seal joints, and butt joints. However, modified ring joints may still allow end butting to occur under severe conditions such as low temperature cold starting and warm up.
- The present invention provides engine piston compression rings which can minimize negative effects of ring gap end butting while optionally providing smaller ring gaps and reduced gas blowby in normal operation.
- The invention controls deflection of the ring ends by using an angled joint and a relieved ring end. The angled joint and an appropriately placed relief area allow the relieved ring end to deflect a substantial distance after butting of the ring ends and before the relieved end engages a wall of an associated ring groove of the piston. The direction of deflection is controlled by the angle and direction of the ring joint. Deflecting the relieved portion of the ring end allows additional relative ring expansion after ring end butting without increasing the ring load against the cylinder bore. Thus, harmful effects of end butting are minimized and the gap between the ring ends can be reduced, resulting in reduced blowby.
- In one embodiment of the invention, a compression ring has a gap that forms an angle with respect to a radius drawn from a longitudinal axis. Butting of the ring ends at the gap causes one end of the ring to be deflected inward and that one end is relieved for a portion along an inner edge. The relieved portion slopes outward toward the ring end where the radial thickness of the ring is smallest. This design creates end relief, which allows the relieved end of the ring to bend into the annular piston ring groove instead of increasing ring load against the cylinder bore.
- A variation of the previously described embodiment has a slot adjacent the relieved portion that extends outward from the inner edge to promote bending of the relieved end. This slot decreases the force required during end butting to move the relieved end inward toward the piston instead of increasing ring load against the cylinder bore.
- In another embodiment of the invention having a similarly angled gap, the relieved portion is generally circumferential with a transition portion to the full ring thickness. This design creates end relief, which allows the relieved end to bend a greater distance than the previous embodiments.
- In a differing fourth embodiment, the compression ring has a gap that forms an angle with respect to the longitudinal axis of the ring. Butting of the ring ends at the gap causes one end of the ring to slide up on the angled other end so that the one end is relieved for a portion along the upper side of the ring. The relieved portion slopes downward toward the ring end where the longitudinal thickness of the ring is smallest. This design creates a form of end relief which allows the relieved end of the ring to slide toward the top of the annular piston ring groove instead of bending in toward the inner diameter of the ring groove like the other embodiments referred to.
- The invention is particularly useful in avoiding negative effects of ring end butting which may occur under severe low temperature cold engine starting and warm-up conditions. However, it can also reduce effects of end butting under other conditions and may be used to reduce ring gap dimensions with resulting reductions of gas blowby during normal engine running.
- These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
- In the drawings:
- FIG. 1 is a top view of a first embodiment of engine piston compression ring according to the invention;
- FIG. 2 is an enlarged side view from the line 2-2 of FIG. 1 showing the gap portion of the ring;
- FIG. 3 is an enlarged top view of the gap portion of the ring shown in FIG. 2;
- FIG. 4 is a view similar to FIG. 3 showing a modified embodiment of piston compression ring;
- FIG. 5 is a view similar to FIGS. 3 and 4 showing another modified embodiment of piston compression ring;
- FIG. 6 is an enlarged fragmentary top view showing the gap portion of a distinct alternative embodiment of piston compression ring according to the invention; and
- FIG. 7 is an enlarged fragmentary side view of the embodiment of FIG. 6.
- Referring now to FIGS. 1 and 2 of the drawings in detail,
numeral 10 generally indicates an engine piston compression ring.Ring 10 includes aninner edge 12,outer face 14,upper side 16, and alower side 18. Agap 20 is cut through the ring to provide for installation and expansion.Ring 10 is centered on alongitudinal axis 22 and has aradius 24 extending through thegap 20. The gap extends parallel with thelongitudinal axis 22. - FIGS. 3-7 following indicate various embodiments of the invention wherein like numerals refer to like features.
- FIG. 3 shows enlarged the portion of the
ring 10 in thecircle 2 of FIG. 1 including thegap 20.Gap 20 is defined by 26, 28 of the ring and is cut at an angle with respect to theopposed ends radius 24. Theinner edge 12 of the ring is cut away adjacent theend 28 to form arelieved portion 30. The relievedportion 30 is sloped outward toward theend 28, where the radial thickness of the ring is smallest. Dashedline 32 indicates the outline of the normal ring thickness, showing the region of end relief. - FIG. 4 is similar to FIGS. 1-3 but differs in that the
ring 33 includes aslot 34 adjacent to relievedportion 30 to increase resilience of the relievedportion 30. - FIG. 5 is similar to FIGS. 1-3 but differs in that
ring 35 has a modified relievedportion 36. Relievedportion 36 has a reduced radial thickness with a generally circumferential configuration and adjoins atransition portion 38 extending to the full ring depth for further increasing resilience. Dashedline 40 indicates the outline of the normal ring thickness. - FIGS. 6 and 7 show another embodiment of
piston compression ring 42 wherein agap 44 is cut through the ring to provide for installation and expansion. The ring is also centered on alongitudinal axis 22 and has aradius 24 extending through thegap 44. The ring differs from the previously described embodiments in that thegap 44 forms an angle with respect to thelongitudinal axis 22 but is aligned with theradius 24.Gap 44 is defined by 46, 48 of the ring. Theopposed ends upper side 16 of the ring is cut away adjacent theend 46 to form arelieved portion 50. The relievedportion 50 slopes downward toward theend 46 where the longitudinal thickness of the ring is smallest. Dashedline 52 indicates the outline of the normal ring thickness, showing the region of end relief. - In operation of the embodiments of FIGS. 1-7 the ring ends may butt in extreme conditions, such as cold engine starting and warm up. In the embodiments of FIGS. 1-5 extreme conditions may cause the
gap 20 to close and the ring ends 26, 28 to butt. Further relative expansion of the ring then causes therelieved end 28 to slide along the oppositeangled end 26 as therelieved end 28 is deflected inward toward the inner diameter of the annular piston ring groove. This allows additional relative expansion of the ring to occur without increasing the ring load against the cylinder bore. - In the embodiments of FIGS. 6-7 extreme conditions may cause the
gap 44 to close and the ring ends 46, 48 to butt. Further relative expansion of the ring then causes therelieved end 46 to slide along the oppositeangled end 48 as therelieved end 46 is deflected upward toward the top of the annular piston ring groove. This allows additional expansion to occur without increasing the ring load against the cylinder bore. - The placement and amount of ring end relief which may be provided may be varied to suit particular engine characteristics, operating conditions and piston ring design. However, the advantages of the concept, of which the foregoing embodiments represent only examples, include extension of the ability of an engine to operate in severe conditions of cylinder bore contraction or piston ring expansion and/or the reduction of ring end gap dimensions with resulting reductions of gas blowby.
- While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.
Claims (9)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/243,967 US6715767B1 (en) | 2002-09-12 | 2002-09-12 | Angled gap compression rings with end relief |
| DE10341782A DE10341782A1 (en) | 2002-09-12 | 2003-09-10 | Compression rings with angled gap and end finishing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/243,967 US6715767B1 (en) | 2002-09-12 | 2002-09-12 | Angled gap compression rings with end relief |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| US20040051252A1 true US20040051252A1 (en) | 2004-03-18 |
| US6715767B1 US6715767B1 (en) | 2004-04-06 |
Family
ID=31991772
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US10/243,967 Expired - Fee Related US6715767B1 (en) | 2002-09-12 | 2002-09-12 | Angled gap compression rings with end relief |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US6715767B1 (en) |
| DE (1) | DE10341782A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2878773A1 (en) * | 2013-11-13 | 2015-06-03 | MTU Aero Engines GmbH | Gas turbine with slotted retention ring |
| US20190257424A1 (en) * | 2018-02-22 | 2019-08-22 | Hyundai Motor Company | Piston ring for engine |
| GB2638278A (en) * | 2024-02-19 | 2025-08-20 | Phinia Delphi Luxembourg Sarl | Fuel pump and sealing arrangement therefor |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1536167B1 (en) * | 2002-05-29 | 2012-08-08 | Nok Corporation | Seal ring |
| US7510195B2 (en) * | 2003-11-21 | 2009-03-31 | Honeywell International Inc. | High temperature and high pressure compressor piston ring |
| DE102006022027A1 (en) * | 2006-05-10 | 2007-11-15 | Mahle International Gmbh | Piston ring for the piston of an internal combustion engine |
| BRPI0605175B1 (en) * | 2006-12-05 | 2020-01-21 | Mahle International Gmbh | piston ring for internal combustion engines |
| JP5029044B2 (en) * | 2007-02-01 | 2012-09-19 | Nok株式会社 | Seal ring |
| EP2136212A4 (en) * | 2007-03-28 | 2012-07-25 | Ntn Toyo Bearing Co Ltd | Rotation sensor |
| ES2710496T3 (en) | 2009-10-12 | 2019-04-25 | Toray Industries | Axial labyrinth seal for spirally wound membrane module systems |
| DE102009052587A1 (en) * | 2009-11-10 | 2011-05-12 | Federal-Mogul Burscheid Gmbh | piston ring |
| RU2016114799A3 (en) * | 2013-10-18 | 2018-06-28 | Exco Technologies Ltd | Wear ring for die-casting piston, die-casting piston incorporating same, and method of forming same |
| EP3246603B1 (en) * | 2015-01-14 | 2020-09-16 | Nok Corporation | Seal ring and sealing structure |
| US10359112B2 (en) * | 2016-03-28 | 2019-07-23 | Progress Rail Locomotive Inc. | Piston ring set for internal combustion engine and system and method thereof |
Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1280739A (en) * | 1915-06-03 | 1918-10-08 | John B Jameson | Piston-ring. |
| US1344342A (en) * | 1918-10-08 | 1920-06-22 | Oscar W Hanson | Piston packing-ring |
| US1357729A (en) * | 1918-06-26 | 1920-11-02 | Eva C Schaap | Piston-ring and mounting therefor |
| US1360820A (en) * | 1919-11-03 | 1920-11-30 | Arthur B Thompson | Piston packing-ring |
| US1360733A (en) * | 1917-04-13 | 1920-11-30 | Deutsch | Piston-ring |
| US1398439A (en) * | 1921-01-18 | 1921-11-29 | Mcmaster Frederick Keith | Piston-ring |
| US1470113A (en) * | 1920-11-11 | 1923-10-09 | Morris A Davis | Piston ring |
| US1499571A (en) * | 1920-11-11 | 1924-07-01 | Morris A Davis | Piston ring |
| US1658440A (en) * | 1926-11-20 | 1928-02-07 | Adam W Hanigan | Piston packing |
| US1757877A (en) * | 1928-10-01 | 1930-05-06 | Fisher H Roberts | Piston ring |
| US1833887A (en) * | 1930-12-03 | 1931-12-01 | William C Andrews | Piston ring |
| US2462586A (en) * | 1946-01-02 | 1949-02-22 | New York Air Brake Co | Seal for resisting high pressures |
| US2569777A (en) * | 1946-10-12 | 1951-10-02 | Hastings Mfg Co | Piston ring |
| US2812196A (en) * | 1954-05-20 | 1957-11-05 | Gen Motors Corp | Piston ring turbine shaft seal |
| US4251083A (en) * | 1979-05-15 | 1981-02-17 | Adriel Montes | Piston ring with tongue and groove joint |
| US4449721A (en) * | 1980-12-18 | 1984-05-22 | Tokico Ltd. | Split piston ring having stepped ends |
| US5087057A (en) * | 1990-01-19 | 1992-02-11 | Kurkowski Ronald C | Helical cut seal |
| US5253878A (en) * | 1991-06-04 | 1993-10-19 | Kabushiki Kaisha Riken | Compression ring for internal-combustion engines |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5618048A (en) | 1988-03-24 | 1997-04-08 | Moriarty; Maurice J. | Piston ring seal having angled ends |
-
2002
- 2002-09-12 US US10/243,967 patent/US6715767B1/en not_active Expired - Fee Related
-
2003
- 2003-09-10 DE DE10341782A patent/DE10341782A1/en not_active Withdrawn
Patent Citations (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1280739A (en) * | 1915-06-03 | 1918-10-08 | John B Jameson | Piston-ring. |
| US1360733A (en) * | 1917-04-13 | 1920-11-30 | Deutsch | Piston-ring |
| US1357729A (en) * | 1918-06-26 | 1920-11-02 | Eva C Schaap | Piston-ring and mounting therefor |
| US1344342A (en) * | 1918-10-08 | 1920-06-22 | Oscar W Hanson | Piston packing-ring |
| US1360820A (en) * | 1919-11-03 | 1920-11-30 | Arthur B Thompson | Piston packing-ring |
| US1470113A (en) * | 1920-11-11 | 1923-10-09 | Morris A Davis | Piston ring |
| US1499571A (en) * | 1920-11-11 | 1924-07-01 | Morris A Davis | Piston ring |
| US1398439A (en) * | 1921-01-18 | 1921-11-29 | Mcmaster Frederick Keith | Piston-ring |
| US1658440A (en) * | 1926-11-20 | 1928-02-07 | Adam W Hanigan | Piston packing |
| US1757877A (en) * | 1928-10-01 | 1930-05-06 | Fisher H Roberts | Piston ring |
| US1833887A (en) * | 1930-12-03 | 1931-12-01 | William C Andrews | Piston ring |
| US2462586A (en) * | 1946-01-02 | 1949-02-22 | New York Air Brake Co | Seal for resisting high pressures |
| US2569777A (en) * | 1946-10-12 | 1951-10-02 | Hastings Mfg Co | Piston ring |
| US2812196A (en) * | 1954-05-20 | 1957-11-05 | Gen Motors Corp | Piston ring turbine shaft seal |
| US4251083A (en) * | 1979-05-15 | 1981-02-17 | Adriel Montes | Piston ring with tongue and groove joint |
| US4449721A (en) * | 1980-12-18 | 1984-05-22 | Tokico Ltd. | Split piston ring having stepped ends |
| US5087057A (en) * | 1990-01-19 | 1992-02-11 | Kurkowski Ronald C | Helical cut seal |
| US5253878A (en) * | 1991-06-04 | 1993-10-19 | Kabushiki Kaisha Riken | Compression ring for internal-combustion engines |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2878773A1 (en) * | 2013-11-13 | 2015-06-03 | MTU Aero Engines GmbH | Gas turbine with slotted retention ring |
| US20190257424A1 (en) * | 2018-02-22 | 2019-08-22 | Hyundai Motor Company | Piston ring for engine |
| US10844956B2 (en) * | 2018-02-22 | 2020-11-24 | Hyundai Motor Company | Piston ring for engine |
| GB2638278A (en) * | 2024-02-19 | 2025-08-20 | Phinia Delphi Luxembourg Sarl | Fuel pump and sealing arrangement therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| DE10341782A1 (en) | 2004-04-08 |
| US6715767B1 (en) | 2004-04-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6715767B1 (en) | Angled gap compression rings with end relief | |
| US6631908B2 (en) | Compression piston ring | |
| US4346685A (en) | Internal combustion engine with gas sealing device | |
| EP0937921B1 (en) | Piston ring and method of mounting the piston ring | |
| EP0952326B1 (en) | Piston of internal combustion engine | |
| CN106103960B (en) | piston ring | |
| US5450783A (en) | Low emission piston ring | |
| US9243583B2 (en) | Piston for an internal combustion engine | |
| US8955488B2 (en) | Piston for use in internal combustion engines | |
| EP3043054B1 (en) | Cuff-ring for a cylinder liner | |
| EP3030809B1 (en) | Piston ring | |
| EP3775630B1 (en) | A piston ring | |
| US6113107A (en) | Self-lubricated and-adjusted piston ring | |
| US4417549A (en) | Sealing arrangement for wet cylinder liners | |
| US20140216388A1 (en) | Engine cylinder mid-stop | |
| US20050110223A1 (en) | Cylinder-head gasket comprising an edge-to-edge stop ring which is connected by means of stapling | |
| US7429048B1 (en) | Piston ring with projection | |
| EP4206498B1 (en) | Combination of piston rings and combined structure of piston and piston rings | |
| US10975920B2 (en) | Synchronizer ring | |
| JPH0979377A (en) | Internal combustion engine pistons | |
| EP4239227B1 (en) | Piston ring for a large two-stroke turbo-charged uniflow-scavenged crosshead internal combustion engine | |
| JPS6346677Y2 (en) | ||
| EP4206497B1 (en) | Combination structure of piston and piston rings | |
| JPH09203463A (en) | Piston ring | |
| US11136936B2 (en) | Piston |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: GENERAL MOTORS CORPORATION, MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MEERNIK, PAUL RICHARD;PERRY, THOMAS ARTHUR;KRAMER, MARTIN STEPHEN;AND OTHERS;REEL/FRAME:013459/0560;SIGNING DATES FROM 20020917 TO 20020918 |
|
| FPAY | Fee payment |
Year of fee payment: 4 |
|
| AS | Assignment |
Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC., MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GENERAL MOTORS CORPORATION;REEL/FRAME:022117/0047 Effective date: 20050119 Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC.,MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GENERAL MOTORS CORPORATION;REEL/FRAME:022117/0047 Effective date: 20050119 |
|
| AS | Assignment |
Owner name: UNITED STATES DEPARTMENT OF THE TREASURY, DISTRICT Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022201/0547 Effective date: 20081231 Owner name: UNITED STATES DEPARTMENT OF THE TREASURY,DISTRICT Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022201/0547 Effective date: 20081231 Owner name: UNITED STATES DEPARTMENT OF THE TREASURY, DISTRICT OF COLUMBIA Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022201/0547 Effective date: 20081231 |
|
| AS | Assignment |
Owner name: CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SEC Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022553/0399 Effective date: 20090409 Owner name: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES, DELAWARE Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022553/0399 Effective date: 20090409 Owner name: CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES, DELAWARE Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022553/0399 Effective date: 20090409 Owner name: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECU Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:022553/0399 Effective date: 20090409 |
|
| AS | Assignment |
Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC., MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:UNITED STATES DEPARTMENT OF THE TREASURY;REEL/FRAME:023124/0470 Effective date: 20090709 Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC.,MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:UNITED STATES DEPARTMENT OF THE TREASURY;REEL/FRAME:023124/0470 Effective date: 20090709 |
|
| AS | Assignment |
Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC., MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNORS:CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES;CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES;REEL/FRAME:023127/0273 Effective date: 20090814 Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC.,MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNORS:CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES;CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES;REEL/FRAME:023127/0273 Effective date: 20090814 |
|
| AS | Assignment |
Owner name: UNITED STATES DEPARTMENT OF THE TREASURY, DISTRICT Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:023156/0001 Effective date: 20090710 Owner name: UNITED STATES DEPARTMENT OF THE TREASURY,DISTRICT Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:023156/0001 Effective date: 20090710 |
|
| AS | Assignment |
Owner name: UAW RETIREE MEDICAL BENEFITS TRUST, MICHIGAN Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:023161/0911 Effective date: 20090710 Owner name: UAW RETIREE MEDICAL BENEFITS TRUST,MICHIGAN Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:023161/0911 Effective date: 20090710 |
|
| AS | Assignment |
Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC., MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:UAW RETIREE MEDICAL BENEFITS TRUST;REEL/FRAME:025311/0725 Effective date: 20101026 Owner name: GM GLOBAL TECHNOLOGY OPERATIONS, INC., MICHIGAN Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:UNITED STATES DEPARTMENT OF THE TREASURY;REEL/FRAME:025245/0347 Effective date: 20100420 |
|
| AS | Assignment |
Owner name: WILMINGTON TRUST COMPANY, DELAWARE Free format text: SECURITY AGREEMENT;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:025327/0262 Effective date: 20101027 |
|
| AS | Assignment |
Owner name: GM GLOBAL TECHNOLOGY OPERATIONS LLC, MICHIGAN Free format text: CHANGE OF NAME;ASSIGNOR:GM GLOBAL TECHNOLOGY OPERATIONS, INC.;REEL/FRAME:025780/0902 Effective date: 20101202 |
|
| REMI | Maintenance fee reminder mailed | ||
| LAPS | Lapse for failure to pay maintenance fees | ||
| STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
| FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20120406 |