Respiratory filter

Details Respiratory filter Respiratory filter

1998-05-19

2002-06-25

Weiss, John G. (Department: 3761)

Surgery

Respiratory method or device

Means for indicating improper condition of apparatus

C128S202270, C128S205230, C128S205290, C128S201170, C128S206240, C073S040000, C055SDIG003, C055SDIG003, C137S908000, C251S339000, C251S349000, C251S354000

Reexamination Certificate

active

06408845

ABSTRACT:

TECHNICAL FIELD
The present invention relates to personal safety inhalation equipment, particularly breathing mask filters or respirators. More particularly, the present invention relates to an improved filter assembly with built-in seal check mechanism configured to enable rapid, effective negative pressure safety seal checks.
BACKGROUND OF THE INVENTION
Negative pressure user seal checks are normally performed on personal air respirators by blocking the inlet portion of the filter cartridge and withdrawing air from the mask apparatus. A tight seal stops incoming air from leaking past the mask, creating a clearly detectable vacuum effect. A leaky seal results in a limited vacuum effect and a continuing flow of air into the mask.
To accomplish this test, the main air passage is blocked off, as with a separate structure such as a flat piece of cardboard or plastic applied against the outer surface of the filter, or by covering the inlet of the filter with the palm(s) of the user's hand(s), and the user inhales as deeply as necessary to effect a collapsing of the respirator mask, due to the vacuum, which signals a good fit. The user's thumbs may also be used to block the main air passage; however, the diameter of the apertures to be covered is normally larger than most user thumbs, providing a less-than-perfect seal for this very important personal safety equipment check.
However, problems arise from the difficulty in preventing air flow into the mask. These problems may arise from the imperfect seal effected by the cardboard or plastic, or the inability to use one's hands to accomplish an effective seal. The latter often happens when the hands are dirty or gloves are worn.
An improvement (see
FIG. 3
) to this method is known in which a cover
100
having a small aperture
102
is snap-fit into place over a cartridge
104
. However, the free airflow cross-sectional area of aperture
102
may in some instances be smaller than the free airflow cross-sectional area of cartridge
104
, so it may become desirable to remove cover
102
from cartridge
104
for use. This action may disturb the fit of the mask, occasionally necessitating a repeat of the mask fit test procedure.


REFERENCES:
patent: 1596060 (1926-08-01), Mase
patent: 2420372 (1947-05-01), Heidbrink
patent: 2449053 (1948-09-01), Burns et al.
patent: 2738669 (1956-03-01), Silverman et al.
patent: 2970594 (1961-02-01), Doak
patent: 3250873 (1966-05-01), Kudlaty et al.
patent: 3433455 (1969-03-01), Cook
patent: 3486366 (1969-12-01), Jackson
patent: 3504542 (1970-04-01), Blevins
patent: 3580051 (1971-05-01), Blevins
patent: 4146025 (1979-03-01), Warneke et al.
patent: 4494538 (1985-01-01), Ansite
patent: 4559939 (1985-12-01), Levine et al.
patent: 4765325 (1988-08-01), Crutchfield
patent: 4807614 (1989-02-01), van der Smissen et al.
patent: 4832011 (1989-05-01), Busch
patent: 4846166 (1989-07-01), Willeke
patent: 4914957 (1990-04-01), Dougherty
patent: 4964900 (1990-10-01), Thompson et al.
patent: 5299448 (1994-04-01), Maryyanek et al.
patent: 5328152 (1994-07-01), Castle
patent: 5364540 (1994-11-01), Sciuto
patent: 5567230 (1996-10-01), Sinclair
patent: 5617849 (1997-04-01), Springett et al.
patent: 5647356 (1997-07-01), Osendorf et al.
patent: 3006823 (1981-09-01), None

Affiliated with

Also associated with

Rating

Respiratory filter does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Respiratory filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Respiratory filter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2925886