Glow plug for diesel engines of motor vehicles
Abstract
Abstract A glow plug for preheating the combustion chamber of a diesel engine includes a tubular metal sheath (5) closed at an end to define a tip and in which an electric heating element spiral (7) is embedded within a powder (6) of an electrically insulating material. The spiral (7) is connected by one end to the sheath tip and and at its other end to a current feeder (4). The filament (8) of the spiral (7) is advantageously made of a Fe-Cr-Al alloy and is coated for an initial length (L 1 ) of the spiral (7), from the connection location thereof with the current feeder (4), with a high electrical conductivity material (9), preferably nickel (Ni) having a very high positive temperature coefficient of resistance with respect to that of the filament (8). The uncoated end length (L 2 ) of the spiral (7) acts as a heating element while the initial coated length (L 1 ) acts as a control resistance element for the supply current upon increase in the sheath temperature. The thickness of the coating (9) and the coated length L 1 of the spiral (7) are chosen to provide the desired electric and thermal characteristics of the glow plug.
Inventors
- 👤 Gilberto Izzi
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |