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US4176639A Expired / Lapsed US ⏱️ 0.0 years remaining

Evaporative emission system for improving engine starting characteristics

Assignee: Toyota Motor Corp
•
Filing: 1977-08-12
•
Granted: 1979-12-04
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Expires: 1997-08-12
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Abstract

Abstract An evaporative emission system for an engine includes a float chamber of a carburetor connected to a charcoal canister via an inlet port and an outlet port. The emission system is characterized in that an electromagnetic opening and closing mechanism for actuating a valve which selectively opens and closes the inlet port is controlled by a temperature-sensitive switch so that evaporation of low-boiling-point components of fuel and absorption thereof by the charcoal is prevented at low temperatures even in case of long periods during which the engine is not running. The starting characteristics of the engine are thus maintained.

Inventors

  • 👤 Osamu Shinoda
  • 👤 Keiichi Okabayashi
  • 👤 Takanori Nagai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 19:57
CPC Classifications
F; F02; F02M; F02M25/00; F02M25/08; F02M25/0836; F02M2025/0845

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 160 words
An evaporative emission system comprising a carburetor, a canister, an ignition key-operated circuit which includes an ON circuit and an OFF circuit, an inlet port connected to said carburetor, outlet port connected to said canister; a valve means communicating said inlet port with said outlet port for opening and closing said inlet port comprising electromagnetic operating mechanism including two separately energized coils one being disposed in said OFF circuit of said ignition key-operated circuit and the other being disposed in said ON circuit of said ignition key-operated circuit, a single valve as closing and opening means against said inlet port coupled to said coils, means forming part of the system which exhibits an operating temperature thereof, and a temperature-sensing switch means in said OFF circuit of said ignition key-operated circuit and responsive to the operating temperature of said means forming part of the system for interrupting current to said electromagnetic mechanism when the operating temperature falls below a given value.
Claim 2
Dependent Claim 160 words
An evaporative emission system comprising a carburetor, a canister, an ignition key-operated circuit which includes an ON circuit and an OFF circuit, an inlet port connected to said carburetor, outlet port connected to said canister; a valve means communicating said inlet port with said outlet port for opening and closing said inlet port comprising electromagnetic operating mechanism including two separately energized coils one being disposed in said OFF circuit of said ignition key-operated circuit and the other being disposed in said ON circuit of said ignition key-operated circuit, a single valve as closing and opening means against said inlet port coupled to said coils, means forming part of the system which exhibits an operating temperature thereof, and a temperature-sensing switch means in said OFF circuit of said ignition key-operated circuit and responsive to the operating temperature of said means forming part of the system for interrupting current to said electromagnetic mechanism when the operating temperature falls below a given value.
Claim 3
Dependent Claim 37 words
An evaporative emission system as set forth in claim 1, wherein said valve means includes a casing, and wherein said valve is equipped with a resilient spring, said spring being positioned between said casing and said valve.
Claim 4
Dependent Claim 27 words
An evaporative emission system, according to claim 1, wherein said temperature-sensing switch means is OPEN at temperatures below 50° C. and CLOSED at temperatures above 50° C.
Claim 5
Dependent Claim 34 words
An evaporative emission system, according to claim 1, wherein said means forming part of the system is a radiator, and wherein said temperature-sensing switch means is a water temperature-sensing switch mounted on said radiator.
Claim 6
Dependent Claim 27 words
An evaporative emission system according to claim 4 wherein said water temperature-sensing switch is OPEN at temperatures below 50° C. and CLOSED at temperatures above 50° C.
Claim 7
Dependent Claim 28 words
An evaporative emission system according to claim 1, wherein said temperature sensing switch means is disposed in said ignition key-operated circuit in series with one of said coils.

References Cited (Backward Citations)

US3191587A Cited
US2875780A Cited
US2842334A Cited
US3221724A Cited
US3456635A Cited
US3534720A Cited
US3680318A Cited
US3831572A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-12-03 1983-06-04 1983-12-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-12-03 1987-06-04 1987-12-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-12-03 1991-06-04 1991-12-04 $7700.00 Window Closed / Lapsed

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