Liquid purification or separation – With alarm – indicator – register – recorder – signal or... – Material level or thickness responsive
Reexamination Certificate
2001-08-22
2003-08-26
Drodge, Joseph (Department: 1723)
Liquid purification or separation
With alarm, indicator, register, recorder, signal or...
Material level or thickness responsive
C210S095000, C210S456000, C116S227000
Reexamination Certificate
active
06610198
ABSTRACT:
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to liquid filters, and more particularly to a service interval change indicator more accurately reflecting filter life.
Liquid filters, including fuel filters, typically have a vertically axially extending housing having an annular filter element extending axially between top and bottom ends and having an inner hollow interior and an outer annular space between the filter element and the housing. The housing has an inlet to the annular space, and an outlet from the hollow interior. Liquid is filtered by flowing from the annular space through the filter element into the hollow interior. The annular space is viewable through the housing, e.g. through a transparent housing side wall, such that an operator or service technician can see the level of liquid in the annular space as an indication of when to replace the filter element. The higher the level of liquid in the annular space the greater the pressure drop across the filter element and hence the greater the plugging of the filter element.
In many applications, the liquid or fuel level, including the rise thereof in the noted annular space, does not accurately reflect filter life. For example, in one application, fuel level in a clear housing reaches the top with 2″ Mercury, Hg, restriction, while the filter element is capable of 8″ Mercury, Hg, restriction. Hence, using fuel level in the noted annular space of the clear housing as an indicator to change the filter element results in a premature such change. This is objectionable because of the less than full life usage of the filter element, the more frequent filter element changes, and the corresponding higher overall cost thereof.
The present invention addresses and solves the above noted objections. In one aspect, the invention delays the rise in liquid level in the noted annular space to correct the otherwise premature indication of a need to change the filter element. In another aspect, liquid level in the noted annular space is allowed to rise to controlled levels providing advance and more accurate indication of a forthcoming need to change the filter element.
REFERENCES:
patent: 2748949 (1956-06-01), James
patent: 2843268 (1958-07-01), Kennedy
patent: 2919807 (1960-01-01), Briggs
patent: 3209520 (1965-10-01), McKinlay
patent: 3386230 (1968-06-01), Reisberg et al.
patent: 3397793 (1968-08-01), MacDonnell
patent: 3506475 (1970-04-01), MacDonnell
patent: 3827566 (1974-08-01), Ponce
patent: 4033881 (1977-07-01), Pall
patent: 4058463 (1977-11-01), Bartik
patent: 4104170 (1978-08-01), Nedza
patent: 4181514 (1980-01-01), Lefkowitz et al.
patent: 4243397 (1981-01-01), Tokar et al.
patent: 4392958 (1983-07-01), Ganzi et al.
patent: 4464263 (1984-08-01), Brownell
patent: 4539107 (1985-09-01), Ayers
patent: 4692175 (1987-09-01), Frantz
patent: 4878929 (1989-11-01), Tofsland et al.
patent: 4882056 (1989-11-01), Degen et al.
patent: 4890444 (1990-01-01), Vander Geisen et al.
patent: 4929354 (1990-05-01), Meyering et al.
patent: 4950400 (1990-08-01), Girondi
patent: 5006235 (1991-04-01), Cooper
patent: 5039413 (1991-08-01), Harwood et al.
patent: 5071456 (1991-12-01), Binder et al.
patent: 5082476 (1992-01-01), Kahlbaugh et al.
patent: 5167683 (1992-12-01), Behrendt et al.
patent: 5238474 (1993-08-01), Kahlbaugh et al.
patent: 5252207 (1993-10-01), Miller et al.
patent: 5306321 (1994-04-01), Osendorf
patent: 5350515 (1994-09-01), Stark et al.
patent: 5364456 (1994-11-01), Kahlbaugh et al.
patent: 5376278 (1994-12-01), Salem
patent: 5415676 (1995-05-01), Tokar et al.
patent: 5423892 (1995-06-01), Kahlbaugh et al.
patent: 5427597 (1995-06-01), Osendorf
patent: 5454858 (1995-10-01), Tokar et al.
patent: 5462679 (1995-10-01), Verdegan et al.
patent: 5507942 (1996-04-01), Davis
patent: 5543047 (1996-08-01), Stoyell et al.
patent: 5622537 (1997-04-01), Kahlbaught et al.
patent: 5628916 (1997-05-01), Stevens et al.
patent: 5660729 (1997-08-01), Baumann
patent: 5669949 (1997-09-01), Dudrey et al.
patent: 5672399 (1997-09-01), Kahlbaugh et al.
patent: 5690765 (1997-11-01), Stoyell et al.
patent: 5695637 (1997-12-01), Jiang et al.
patent: 5700304 (1997-12-01), Foo
patent: 5736044 (1998-04-01), Proulx et al.
patent: 5762669 (1998-06-01), Kahlbaugh et al.
patent: 5762670 (1998-06-01), Kahlbaugh et al.
patent: 5766449 (1998-06-01), Davis
patent: 5766468 (1998-06-01), Brown et al.
patent: 5779900 (1998-07-01), Holm et al.
patent: 5792227 (1998-08-01), Kahlbaugh et al.
patent: 5797973 (1998-08-01), Dudrey et al.
patent: 5800581 (1998-09-01), Gielink et al.
patent: 5800587 (1998-09-01), Kahlbaugh et al.
patent: 5814219 (1998-09-01), Friedmann et al.
patent: D402361 (1998-12-01), Nepsund et al.
patent: D404807 (1999-01-01), Nepsund et al.
patent: 5858044 (1999-01-01), Nepsund et al.
patent: 5858224 (1999-01-01), Schwandt et al.
patent: 5871557 (1999-02-01), Tokar et al.
patent: D406315 (1999-03-01), Rao et al.
patent: D406316 (1999-03-01), Rao et al.
patent: 5876601 (1999-03-01), Geibel et al.
patent: D407808 (1999-04-01), Nepsund et al.
patent: 5935284 (1999-08-01), Tokar et al.
patent: RE37165 (2001-05-01), Davis
patent: 2002/0125178 (2002-09-01), Smith et al.
patent: 48310 (1982-03-01), None
patent: 470485 (1992-02-01), None
patent: 631803 (1995-01-01), None
patent: 711588 (1996-05-01), None
patent: 844013 (1998-05-01), None
patent: 860604 (1998-08-01), None
patent: 11253706 (1999-09-01), None
Clevenger, Jr. John W.
Jiang Zemin
Prater Ted Franklin
Scheuren John
Andrus Sceales Starke & Sawall LLP
Cecil Terry K.
Drodge Joseph
Fleetguard Inc.
LandOfFree
Liquid filter with change interval 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 Liquid filter with change interval indicator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid filter with change interval indicator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3084025