Signals and indicators – Indicators – Fluid flow
Reexamination Certificate
2002-01-31
2003-08-12
Gutierrez, Diego (Department: 2859)
Signals and indicators
Indicators
Fluid flow
C116SDIG002, C116S273000, C116S272000
Reexamination Certificate
active
06604486
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to restriction indicators, and more particularly to restriction indicators for use with combustion engine intake air cleaners.
Background of the Invention
Restriction indicators are commonly used to indicate when it is recommended to service the air cleaner system of an internal combustion engine. Engine air cleaner systems usually use barrier filtration media that requires periodic servicing to ensue that adequate air flow is provided to the engine. Restriction indicators typically are connected to the air outlet of the air cleaner system upstream of the intake of the engine. Many mechanical restriction indicators employ a bellows-type diaphragm vented to the atmosphere, which is resisted from expanding by a compression spring. As the air cleaner system becomes more contaminated, the differential pressure between the “atmospheric” /high pressure side and the “negative” /low pressure side of the restriction indicator increases, thereby causing the diaphragm to expand. When the differential pressure has reached a certain level, the diaphragm typically becomes locked in an expanded position, and a constant warning signal is provided to the user that the air cleaner system is recommended to be serviced. An example of such prior art restriction indicators is shown in U.S. Pat. No. 3,443,365.
A problem associated with restriction indicators is providing a locking mechanism which will consistently lock and release after repeated use. In many designs, the locking mechanism includes a resettable plunger which engages a latch to lock the diaphragm in an expanded warning position. An example of this is shown by the '365 patent, in which the plunger is bent to engage the latch off-center. Another example is shown by U.S. Pat No. 4,445,456 which discloses a restriction indicator having a ratchet that swings through an arc and interlocks with a floating indicator. An inherent disadvantage of this indicator is that side loads from the ratchet can cause canting, misalignment, friction and binding of the floating indicator.
SUMMARY OF THE INVENTION
According to the present invention, a restriction indicator for an air cleaner system is provided.
One aspect of the present invention relates to a restriction indicator for an air cleaner system of an internal combustion engine. The restriction indicator includes a housing divided into first and second chambers by a diaphragm. A signal member is connected to the diaphragm. The signal member is moveable along an axis between a reset position and a first indicator position, and defines an axial opening within which a first retaining shoulder is located. A guide member is provided for guiding the signal member as the signal member is moved between the reset position and the first axial position. A retaining member is provided for retaining the signal member in the first indicator position. The retaining member extends within the axial opening of the signal member and includes at least two fingers that project radially outward from the axis. The fingers are configured to engage the first retaining shoulder to retain the signal member in the first indicator position. The restriction indicator further includes a reset button for deflecting the fingers radially inward to disengage the fingers from the first retaining shoulder thereby allowing the signal member to be returned to the reset position. The reset button includes a portion that extends within the axial opening of the signal member between the retaining member and the signal member.
These and other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto. However, for a better understanding of the invention and its advantages, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter in which there are illustrated and described preferred embodiments of the invention.
REFERENCES:
patent: 1176338 (1916-03-01), Bromberg
patent: 1874913 (1932-08-01), Crowley
patent: 3066527 (1962-12-01), Stein et al.
patent: 3068831 (1962-12-01), Witchell et al.
patent: 3258960 (1966-07-01), Baden et al.
patent: 3283584 (1966-11-01), Coffing
patent: 3335694 (1967-08-01), Dwyer et al.
patent: 3443365 (1969-05-01), Lee et al.
patent: 3465707 (1969-09-01), Kashiwaba
patent: 3916817 (1975-11-01), Kemp
patent: 3939457 (1976-02-01), Nelson
patent: 3963891 (1976-06-01), De Magondeaux
patent: 4014209 (1977-03-01), Emerick
patent: 4020783 (1977-05-01), Anderson et al.
patent: 4029041 (1977-06-01), Genshpring et al.
patent: 4031847 (1977-06-01), Sullivan
patent: 4033733 (1977-07-01), Nelson
patent: 4060050 (1977-11-01), Simonsson
patent: 4116156 (1978-09-01), Draxler
patent: 4153003 (1979-05-01), Willis
patent: 4162660 (1979-07-01), Albertson et al.
patent: 4184376 (1980-01-01), Thomas et al.
patent: 4189707 (1980-02-01), Ermert
patent: 4189724 (1980-02-01), Onuma et al.
patent: 4193292 (1980-03-01), Simonsson
patent: 4254731 (1981-03-01), Taylor
patent: 4365582 (1982-12-01), Boyer et al.
patent: 4369728 (1983-01-01), Nelson
patent: 4445456 (1984-05-01), Nelson
patent: 4445457 (1984-05-01), Bargman
patent: 4651670 (1987-03-01), Silverwater
patent: 4688511 (1987-08-01), Gerlach et al.
patent: 5188728 (1993-02-01), Traonvoez et al.
patent: 5351035 (1994-09-01), Chrisco
patent: 5606311 (1997-02-01), Polidan et al.
patent: 5774056 (1998-06-01), Berry, III et al.
patent: 6026539 (2000-02-01), Muow et al.
patent: 6161417 (2000-12-01), Nepsund
patent: 6307466 (2001-10-01), Ferris
patent: 6327902 (2001-12-01), Berry, III et al.
patent: 26 17 972 (1976-04-01), None
patent: 25 50 162 (1977-05-01), None
patent: 2 141 993 (1973-01-01), None
patent: 2 298 097 (1975-01-01), None
patent: 2 338 395 (1976-01-01), None
patent: 2 568 484 (1985-07-01), None
patent: WO 97/06363 (1997-02-01), None
patent: WO 99/25974 (1999-05-01), None
Couillard William E.
Diver Robert W.
Kaul Wayne A.
Krisko William J.
Matthys Bernard A.
Donaldson & Company, Inc.
Gutierrez Diego
Merchant & Gould P.C.
Reis Travis
LandOfFree
Restriction indicator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Restriction indicator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Restriction indicator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3078551