NZ612740B2 - Low profile frame for a filter incorporating a negative pressure check mechanism - Google Patents
Low profile frame for a filter incorporating a negative pressure check mechanism Download PDFInfo
- Publication number
- NZ612740B2 NZ612740B2 NZ612740A NZ61274012A NZ612740B2 NZ 612740 B2 NZ612740 B2 NZ 612740B2 NZ 612740 A NZ612740 A NZ 612740A NZ 61274012 A NZ61274012 A NZ 61274012A NZ 612740 B2 NZ612740 B2 NZ 612740B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- filter
- frame
- halves
- upper half
- cantilever beam
- Prior art date
Links
- 230000029058 respiratory gaseous exchange Effects 0.000 claims abstract description 50
- 238000007789 sealing Methods 0.000 claims description 15
- 229920000642 polymer Polymers 0.000 claims description 2
- 235000012771 pancakes Nutrition 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- -1 polypropylenes Polymers 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 230000000241 respiratory Effects 0.000 description 3
- 239000004698 Polyethylene (PE) Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000000875 corresponding Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000003522 irritant Effects 0.000 description 1
- 239000002085 irritant Substances 0.000 description 1
- 231100000021 irritant Toxicity 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 239000011236 particulate material Substances 0.000 description 1
- 238000004023 plastic welding Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 230000001681 protective Effects 0.000 description 1
- 238000009420 retrofitting Methods 0.000 description 1
- 230000002588 toxic Effects 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B18/00—Breathing masks or helmets, e.g. affording protection against chemical agents or for use at high altitudes or incorporating a pump or compressor for reducing the inhalation effort
- A62B18/08—Component parts for gas-masks or gas-helmets, e.g. windows, straps, speech transmitters, signal-devices
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B23/00—Filters for breathing-protection purposes
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B23/00—Filters for breathing-protection purposes
- A62B23/02—Filters for breathing-protection purposes for respirators
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B27/00—Methods or devices for testing respiratory or breathing apparatus for high altitudes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2271/00—Sealings for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2271/02—Gaskets, sealings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/0002—Casings; Housings; Frame constructions
- B01D46/0005—Mounting of filtering elements within casings, housings or frames
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
Abstract
Disclosed is a low-profile filter frame for maintaining an open filter plenum configuration during normal operation, and for enabling quick and reliable negative pressure testing. The frame has upper and lower halves. A breathing tube in the lower half connects to a respirator port. The upper and lower halves snap together to maintain the structure in an assembled configuration. The halves also include features that bias the halves apart when the device is in the assembled configuration, thereby maintaining the breathing tube open. To perform a fit test, a force is applied to an outer surface of the upper half, which moves the halves together, in opposition to the bias, so that the upper half seals against the breathing tube. The frame can be provide in as a single-piece, with a living hinge connecting upper and lower halves, or the upper and lower halves can be separate pieces. wer halves snap together to maintain the structure in an assembled configuration. The halves also include features that bias the halves apart when the device is in the assembled configuration, thereby maintaining the breathing tube open. To perform a fit test, a force is applied to an outer surface of the upper half, which moves the halves together, in opposition to the bias, so that the upper half seals against the breathing tube. The frame can be provide in as a single-piece, with a living hinge connecting upper and lower halves, or the upper and lower halves can be separate pieces.
Description
LOW PROFILE FRAME FOR A FILTER
INCORPORATING A NEGATIVE PRESSURE CHECK MECHANISM
Cross-Reference to Related ations
This application claims priority to pending U.S. Provisional Patent Application Serial No.
,761, filed January 20, 2011, the entirety of which provisional application is incorporated
herein by reference.
Field
The ion is lly related to the field of air filtration systems, more particularly to
atory protection devices, and specifically relating to an improved e filter
arrangement for use with respiratory protection devices.
Background
Respiratory protection devices are used in a wide variety of service applications to protect
users from the effects of toxic or irritant particulate materials dispersed in the air. Such
respirators are only fully effective, however, if they fit the user’s face and head and if they have
been donned properly. Performing a negative pressure fit check is a common method of
ensuring proper ece fit and to ensure that the facepiece has been properly donned. This
can typically be accomplished by using ones palms to cover the inlet of the filters installed on the
respirator facepiece and inhaling. The inhaled breathe causes a ve pressure within the
facepiece and allows the user to assess the seal and leak tightness of the facepiece by observing
the pressure decay within the facepiece. When using ones palms to cover the inlet of the filters,
however, the force required to effect a proper seal between the palms and the filter may be
substantial and may cause the user to deflect the face seal of the respirator creating either false
ve or false ve results. When using low profile particulate filters (often referred to as
“pancake” filters) this fit check can become difficult if not impossible as there may be no way to
tely cover the entire media surface due to its size/shape.
Some particulate s employ a rigid frame around the outside such that the media is
only exposed on the top. This allows for the effective use of palm sealing, but such filters are
typically neither low profile nor flexible enough to interface with other personnel protective
equipment the way a typical pancake filter can. Other filter styles employ semi flexible internal
AH26(9355632_1):AEM
frame structures which allow for the desirable personnel tive equipment interfaces
previously discussed. However, such styles do not allow the user to perform a negative pressure
leak check as the user cannot cover the entire e area of the filter media due to their size and
shape.
It would be desirable to provide an improved “pancake” style ulate and/or nuisance
filter that orates a negative pressure check mechanism that is easily and reliably actuated
by a user.
Object of the Invention
[0005a] It is the object of the present invention to substantially overcome or at least ameliorate
one or more of the above disadvantages or to provide a useful alternative.
Summary
[0005b] According to a first aspect of the invention there is disclosed herein a single piece filter
frame structure comprising:
a frame having upper and lower halves and a living hinge disposed therebetween, the
upper and lower halves configured to ate with a low profile particulate filter; the upper
and lower halves further comprising a snap joint for engaging the upper half to the lower half
when the device is folded at the living hinge to maintain the structure in an assembled
configuration;
wherein the frame has an open plenum configuration in which a filter plenum is held in
an open position, and a negative pressure check configuration in which a portion of the upper
half seals against a portion of the lower half to facilitate seal and leak tightness of a facepiece
associated with the filter structure.
[0005c] According to a second aspect of the invention there is disclosed herein a filter ure
comprising:
a frame having an upper n and a lower n, the upper and lower portions
configured to cooperate with a low profile particulate filter, the upper and lower portions
AH26(9355632_1):AEM
including a fulcrum bar and cantilever beam ation to bias the upper and lower
portions apart;
wherein the frame is selectively movable between an open plenum configuration and a
ve pressure check configuration;
wherein when the frame is in the open plenum configuration, a filter plenum is held in an
open position, and
wherein when the frame is in the a negative pressure check configuration, the upper
portion seals against the lower portion to facilitate seal and leak tightness of a ece
associated with the filter structure.
[0005d] According to a third aspect of the invention there is disclosed herein a filter arrangement
comprising:
a frame having upper and lower halves and a living hinge disposed therebetween;
a low profile particulate filter positioned to cooperate with the upper and lower halves;
wherein the lower half of the frame includes a breathing tube for connecting to an
ated port of a respirator;
wherein the frame further comprises a snap joint for ng the upper half and the
lower half when the device is folded at the living hinge, the snap joint to maintain the structure in
an assembled configuration;
wherein the lower half further includes a fulcrum bar to engage a cantilever beam of the
upper half to bias the upper and lower halves apart when the device is in the led
configuration; and
wherein when the ure is in the assembled configuration, a force applied to an outer
surface of the upper half moves the upper half toward the lower half in opposition to the bias of
the fulcrum bar and cantilever beam so that the upper half seals against the breathing tube.
A single piece filter frame structure is disclosed. The structure includes a frame having
upper and lower halves and a living hinge disposed therebetween. The upper and lower halves
can be configured to cooperate with a low profile particulate filter. The upper and lower halves
may r include a snap joint for engaging the
AH26(9301507_1):AEM
configuration. The lower half further es a fulcrum bar to engage a cantilever
beam of the upper half to bias the upper and lower halves apart when the device is in
the folded configuration Thus arranged, when the structure is in the folded
configuration, a force applied to an outer surface of the upper half moves the upper
half toward the lower half in opposition to the bias of the fulcrum bar and cantilever
beam so that the upper half seals against the breathing tube.
A filter structure is disclosed, comprising a single-piece frame having
upper and lower halves and a living hinge disposed therebetween. The lower half
may include a ing tube for connecting to an associated port of a respirator. The
upper and lower halves further may include a snap joint for engaging the upper half to
the lower half when the device is folded at the living hinge. The snap joint may
maintain the structure in a folded configuration. The lower half may further include a
fulcrum bar to engage a cantilever beam of the upper half to bias the upper and lower
halves apart when the device is in the folded configuration. Thus arranged, when the
structure is in the folded configuration, a force applied to an outer e of the upper
half may move the upper half toward the lower half in opposition to the bias of the
fulcrum bar and cantilever beam so that the upper half seals against the ing
tube.
Brief Description of the Drawings
By way of example, a specific embodiment of the disclosed device will
now be bed, with reference to the accompanying drawings:
is a side view of the disclosed internal filter frame ure in the
unassembled and assembled configurations;
is an isometric view of the internal filter frame structure of
showing the device in the unassembled configuration;
is an isometric view of the internal filter frame structure of
showing the device in the assembled uration;
is an isometric view of an alternative embodiment of an internal
filter frame structure ing to the disclosure, showing the device in the
unassembled configuration;
is a side view of the ative frame structure of in the
unassembled and assembled configuration;
is an isometric view of a further alternative embodiment of an
internal filter frame structure according to the disclosure, showing the device in the
mbled configuration;
is a side view of the frame structure of in the
unassembled and assembled configurations;
is a top transparent view of the internal filter frame structure of
showing the device in the assembled configuration and in context with a filter
element;
is a cross section view of the frame structure and filter element of
, taken along line 6B-6B of ;
FIGS. 7A and 7B are isometric views of a multi-piece embodiment of the
internal filter frame structure according to the disclosure; and
is an isometric view of the internal filter frame structure of FIGS.
7A and 7B in the assembled uration.
Detailed Description
An improved flexible “pancake” style particulate and/or nuisance filter is
disclosed that incorporates a ve pressure check ism that is easily
actuated by a user. The ve pressure check mechanism is incorporated into a
single frame structure that employs the use of a “living hinge” to connect the
breathing tube structure to the sealing mechanism structure. In the standard position
the sealing mechanism frame is bent over the breathing tube frame and held in
tension, which biases the frame open. In addition, this bias serves to hold an open
plenum, which is the normal operating configuration of the filter. From this open
plenum configuration, a force can be applied to the structure to overcome the bias and
to press the sealing mechanism against the breathing tube, which seals off the
breathing tube so that a negative pressure test of the ated facepiece or
respiratory protection device can be performed. Thus, the disclosed design provides
multi-functionality not found in prior devices. That is, a force can be applied to the
frame to facilitate a negative pressure check (i.e., during fit testing), and then the force
can be ed so that the device assumes a normal open plenum configuration for
use.
The disclosed design solves problems inherent the prior art designs by
incorporating a g mechanism inside the filter media that directly seals to the
breathing tube, and thus little force is required in order to affect the fit test seal. This
is lished while also keeping the profile of the filter low.
The sed design includes a sealing mechanism that is integral to the
frame structure of the filter. The sealing mechanism is easily operated by the user
with minimal force so as not to adversely affect the seal between the respirator and
the user when the check is performed. The disclosed design can be moldable as a
single piece, thus ng part count and cost. atively, the design can be
formed in multiple pieces and fit together during assembly. As noted, the disclosed
design can hold the plenum of the filter media open, thus allowing for proper
distribution of air flow across the media when in the standard (i. 6., operating)
position. The disclosed design may also facilitate closure of plenum, by application
of a small force to the filter frame, to enable a negative pressure check of the filter to
be performed.
Referring now to FIGS. 1 and 2, the disclosed design includes a frame
structure 1 that provides a negative pressure check mechanism in a single piece that is
molded in a flat position (position “A”) and includes a living hinge 2 that enables the
frame structure 1 to be folded in the direction of arrow “B” into a standard operating
position (position “C,” shown in dashed lines).
shows the frame structure 1 in the flat on (“A”), which is how
the frame will be , for embodiments in which the frame structure 1 is ed
as a single piece. The frame structure 1 includes a lower half 4 and an upper half 6
positioned on opposite sides of the living hinge 2. The lower half 4 includes a
breathing tube 8 that can be configured to connect to a respirator (not shown) using
any of a variety of connection arrangements (e.g., bayonet, thread, push to connect,
etc.). The ular configuration used to effect such connections can be
incorporated within the breathing tube 8 (for e, along inner surface 9), thus
keeping the profile of the structure as low as possible against the respirator.
To assemble the frame structure 1 for use, the upper half 6 and lower half
4 are folded toward each other in the direction of arrow “B” until the upper half
overlies the lower half 4 ion “C” of . To hold the halves 4, 6 together, a
projection 10 in the lower half 4 engages a corresponding recess 12 in the upper half
6. In the illustrated embodiment, this projection 10 is a snap connector that includes a
pair of outwardly biased fingers 10a, b having barbed tips 11a, 11b. When the fingers
10a, b are pressed into the recess 12 they compress together to enable the barbed tips
11a, b to pass though the recess 12. Once the tips 11a, b have passed h the
recess 12 the arms 10a, b spring back outward to lock the projection 10 in the recess
12. If necessary, the halves 4, 6 can be unlocked by squeezing the tips 11a, b together
and g the projection 10 back through the recess 12. It will be iated that
although the projection is illustrated in the lower half, and the recess is shown in the
upper half, the two could be switched so that the projection is provided in the upper
half and the recess in the lower half.
Thus, when the frame structure 1 is folded, the snap mechanism holds the
lower and upper halves 4, 6 in the standard (i.e., operating) position. In operation, it
is desirable that the breathing tube 8 be held open to allow for the s of air to the
filter media surrounding the frame structure 1. Thus, the frame structure 1 may
include one or more features designed to bias the upper half 6 away from the
breathing tube 8 during normal operation. In the illustrated embodiment, this
achieved through the interaction of a fulcrum bar/cantilever beam arrangement.
As shown, the lower half 4 includes a fulcrum bar 14 with first and second
legs 14a, 14b that connect to opposite lateral sides 4a, 4b of the lower half 4. The
fulcrum bar 14 also includes a central portion 14c that extends upward toward the
upper half 6 when the structure 1 is folded. On the upper half 6, opposite lateral sides
of the half serve as ever beams 16a, 16b that engage the central portion 140
and/or the first and second legs 14a, of the fulcrum bar 14. Thus, when the structure 1
is folded (position “C” of , the fulcrum bar 14 engages the cantilever beams
16a, b, and biases the upper half 6 away from the lower half 4 and spaces the upper
half 6 a distance “S” away from the breathing tube 8.
Though the halves are biased apart via the interaction of the fulcrum bar
and ever beams, the upper and lower halves remain connected via the interaction
between the snap connector 10 and recess 12.
Referring now to a negative pressure leak check can be performed
by pressing down on the upper half 6 along the direction of arrow “D.” By applying a
light force to the top g mechanism 18 oned on the upper half 6, the user
can selectively seal the breathing tube 8 to achieve a seal between a soft seal 20 on the
upper half 6 and the breathing tube 8. In one ment, the soft seal 20 may be a
piece of die cut rubber or elastomeric material attached to the surface of the upper half
6. atively, the soft seal 20 may be an overmolded piece of material suitable to
provide a desired sealing between the upper half 6 and the breathing tube 8. Use of a
soft seal is an advantage e it can easily conform to the surface of the breathing
tube 8, thus reducing the impact of any surface discontinuities and/or misalignment
between the upper half 6 and the breathing tube 8.
As force is applied to the top sealing ism 18, the cantilever beams
16a, 16b are bent about the m bar 14. The amount of force ed to affect a
seal is controllable by the cross section of the cantilever beams 16a, b, the length of
the beams, and position of the fulcrum bar 14. The amount of force required should
be kept to a minimum such that when the force is applied it does not translate through
the mask face seal and affect the seal of the respirator to the users face. It will also be
iated that the use of a soft seal can also advantageously reduce the force
required to affect a seal between the upper half 6 and the breathing tube 8.
It will be appreciated that although the illustrated embodiment shows a
pair of cantilever beams and a fulcrum bar having a pair of legs and a central portion,
other bar and beam arrangements can also be used to bias the halves in the open
on. For example, the fulcrum bar could comprise a pair of bars, while the
cantilever beams may instead be a single beam. Other biasing arrangements are also
contemplated.
For example, FIGS. 4A and 4B show an embodiment of a frame structure
100, including lower and upper halves 104, 106 connected at a living hinge 102. With
this embodiment, however, the outward g is provided by a fulcrum bar 107 on
the lower half 104 which bears upon a flexible midsection 109 of the upper half 106
when the halves are folded together at the living hinge 102 to obtain the assembled
configuration (see , dashed lines). As can be seen, the lower and upper
halves 104, 106 are held together by a snap connector, which in this embodiment
includes a pair of spaced apart arms 110a, 110b forming a recess 112 therebetween.
The recess 112 may be sized to be the same width as, or slightly greater than, the
width of the midsection 109 of the upper half 106. The spaced apart arms 110a, 110b
can have barbed tips 111a, 1 1 1b ed at distal ends f, and the barbed tips
may extend into the recess 112. Thus arranged, when the midsection 109 of the upper
half 106 is pressed into the recess 112 of the lower half 104, midsection 109 ts
the barbed tips 111a, 111b and pushes the arms 110a, 110b apart so that the
midsection 109 can pass into the recess 112. Once midsection 109 passes the barbed
tips 111a, 111b, the arms 110a, 110b spring back inward to lock the midsection 109 in
the recess 112. If desired, the halves 104, 106 can be unlocked by pressing the tips
111a, b apart and pulling the midsection 109 of the upper half 106 back through the
recess 112.
As shown in , when the upper half 106 is locked to the lower half
104, the midsection 109 of the upper half bears against the fulcrum bar 107, biasing
the upper half 106 away from the lower half 104 and spacing the upper half 106 a
distance “S” away from the breathing tube 108. This provides the previously
described open plenum uration, which is the normal operating configuration.
To perform fit g, slight pressure can be applied to the upper half 106 (in the
direction of arrow “D”) to overcome the bias and to seal the upper half 106 to the
breathing tube 108.
One advantage of the snap arrangement of FIGS. 4A and 4B is that the
arms 110a, 110b are positioned between the fulcrum bar 107 and the living hinge 102,
which enables the upper half 106 to be “pre—stressed” by positioning the snap
connector slightly lower than the fulcrum bar 107. This arrangement allows for
enhanced bias as ed to arrangements in which bias is achieved only through
cantilevering the upper half on the fulcrum.
As with the embodiment of FIGS. 1-3, the embodiment of FIGS. 4A and
4B can be molded as a single piece in the flat configuration (position “A”) of . Folding the lower and upper halves 104, 106 together in the direction of arrow
“B” ures the frame structure 100 into the standard operating on (position
“C,” shown in dashed lines.)
FIGS. 5A and 5B show yet another biasing arrangement for a frame
structure 200 in accordance with the disclosure. As with the previous embodiments,
the frame ure 200 es lower and upper halves 204, 206 connected at a
living hinge 202. With the , 5B embodiment, however, outward biasing is
provided by a fulcrum ramp 207 on the lower half 204 which bears upon first and
second side portions 205 a, 205b of the upper half 206 when the halves are folded
together at the living hinge 202 to obtain an assembled configuration. The lower and
upper halves 204, 206 are held in the assembled configuration by a snap connector,
which in this embodiment include an arm 210 oned on the lower half 204, which
is configured to be received in a recess 212 in the upper half 206. The arm 210 can
include a barbed tip 211 at a distal end thereof. Thus arranged, when the lower and
upper halves 204, 206 are folded together along the living hinge 202 in the direction
of arrow “B,” the arm 210 is pressed into the recess 212 of the lower half 204. A
surface adjacent to the recess 212 contacts the barbed tip 211 and pushes the arms 210
back slightly so that the arm can pass into the recess 212. Once the barbed tip 211
passes through the recess 212, the arm 110 springs back to lock the arm 210 in the
recess 212, thereby locking the halves 204, 206 together. If desired, the halves 204,
206 can be unlocked by pressing the tip 211 back and pulling the arm 210 back
h the recess 212.
As noted, when the upper half 206 is locked to the lower half 204, the first
and second side portions 205a, 205b of the upper half 206 bear against the fulcrum
ramp 207, which biases the upper half 206 away from the lower half 204 and spaces
the upper half 206 a distance away from the breathing tube 208 in a manner similar to
that shown in relation to the prior embodiments. This provides the previously
described open plenum configuration, which is the normal operating uration.
As with the prior embodiments, to perform fit testing, slight pressure can be applied to
the upper half 206 to overcome the bias and to seal the upper half 206 to the breathing
tube 208.
As with the us embodiments, the embodiment of FIGS. 5A and 5B
can be molded as a single piece in the flat configuration shown. Folding the lower
and upper halves 204, 206 together in the direction of arrow “B” configures the frame
structure 200 into the assembled configuration (i.e., standard operating position) as
previously described.
With the exception of the described alternative biasing arrangements, the
frame structures 100, 200 include the same features as the frame structure 1. For
example, the lower half 104, 204 includes a breathing tube 108 that can be configured
to connect to a respirator (not shown) using any of a y of tion
arrangements (e.g., bayonet, thread, push to connect, etc.). The upper halves 106, 206
may include a soft seal 20 on the upper half 6 to seal against the breathing tube 8. As
previously noted, the soft seal 20 may be a piece of die cut rubber or elastomeric
al attached to the e of the upper half 6. atively, the soft seal 20
may be an overmolded piece of material suitable to provide a desired sealing between
the upper half 6 and the breathing tube 108, 208.
FIGS. 6A and 6B show the disclosed frame structure 1 in relation to a low
profile particulate filter (i.e., a pancake style filter) including a plurality of filter media
portions 22, 24. The configuration of FIGS. 6A and 6B illustrates a rd position
for maintaining a plenum between top 22 and bottom 24 filter media ns, with
space “S” formed between the upper half 6 and the breathing tube 8. As will be
appreciated, this arrangement allows for even air flow distribution through all parts of
the filter media when the device is in the standard position. As will be appreciated,
the frame structure 1 can be implemented in any application in which a pancake style
filter is used. gh FIGS. 6A and 6B show the frame structure 1 in relation to
the filter media ns 22, 24, it will be appreciated that a ntial similar
configuration will be obtained using the frame structures 100, 200 described in
relation to FIGS. 4A, 4B, 5A and 5B.
As previously noted, the disclosed frame structure 1, 100, 200 can be
molded as a single piece. Thus, the structure can be made from any of a variety of
polymer materials, including polypropylenes, polyethylenes and derivations thereof.
A variety of benefits are provided by the disclosed device. For example,
incorporating a living hinge into the design enables the structure to be molded as a
single flat piece, and then folded into the standard configuration. Such an
ement can reduce part count as well as cost and complexity of parts/tooling.
Referring now to FIGS. 7A, 7B and 8, an embodiment of the disclosed
frame structure 300 is shown in which the lower and upper halves 304, 306 are not
connected by a living hinge, but rather are ed as separate . The lower
half 304 can include a breathing tube end 305 and an opposite engagement end 307.
The breathing tube end 305 includes a breathing tube 308 similar to that described in
relation to the previous embodiments. The engagement end 307 includes a receiving
structure 310 having a recess 312 disposed therein and configured to receive a portion
of the upper half 306. A raised snap member 314 is positioned adjacent to the mouth
of the recess 312.
The upper half 306 of the frame ure 300 has a sealing cover end 316
and an opposite engagement end 318. The engagement end 318 has a snap element
320 with an underlying recess (not shown) configured to receive the raised snap
member 314 of the lower half 304 when the engagement end 318 is received in the
recess 312.
shows the lower and upper halves 304, 306 in the assembled
configuration. The upper half 306 overlies the lower half 304, and the respective
engagement ends 307, 318 of the lower and upper halves are d together.
Specifically, the engagement end 318 of the upper half 306 is slid into the recess 312
of the ing structure 310 of the lower half 304 until the raised snap member 314
snaps into the underlying recess of the snap element 320. In this assembled
configuration, the sealing cover end 316 of the upper half 306 is biased away from the
breathing tube 308 of the lower half to provide a space “S” between the upper half
306 and the breathing tube 308. As with previous embodiments, this arrangement
allows for even air flow bution through all parts of the associated filter media
when the device is in the standard position.
A negative pressure leak check can be performed by pressing down on the
upper half 306 in the direction of arrow “D.” By applying a light force to the upper
half 306, the user can selectively seal the breathing tube 308 to achieve a seal between
a soft seal (similar to that shown in on the upper half 306 and the breathing
tube 308. In one embodiment, the soft seal may be a piece of die cut rubber or
elastomeric material ed to the surface of the upper half 306. Alternatively, the
soft seal may be an overmolded piece of al suitable to provide a desired sealing
between the upper half 306 and the breathing tube 308.
The lower and upper halves 304, 306 may be coupled permanently or
semi-permanently using ves, plastic welding and/or riveting ques, in
addition to or as an alternative to the illustrated snap configuration.
It will be appreciated that by ing the lower and upper halves 304,
306 as separate pieces, the two can be fabricated from different materials. One
age of such an arrangement is that the lower and upper halves can be of
different flexibilities, strengths, toughnesses or other desired physical characteristic.
One or both of the upper and lower halves 304, 206 can be formed from a polymer
such as polypropylene, polyethylene, and derivations thereof.
Using a biasing arrangement to bias the device into the standard position
enables fine control of the force necessary to affect a fit seal. Further, providing a
substantially open breathing tube allows for retrofitting of any type of connection
method, and also maintains the profile of the filter very low where it connects to a
respirator.
Also, the negative pressure mechanism frame structure enables a plenum
to be held open when not performing a seal test. Use of a soft seal to seal against the
breathing tube provides enhanced sealing efficiency with low force. Other advantages
will be apparent to those of skill in the art.
While certain embodiments of the disclosure have been bed herein, it
is not intended that the disclosure be d thereto, as it is intended that the
disclosure be as broad in scope as the art will allow and that the specification be read
likewise. ore, the above description should not be construed as limiting, but
merely as exemplifications of ular ments. Those skilled in the art will
envision other modifications within the scope and spirit of the claims appended
hereto.
Claims
Claims (20)
- l. A single piece filter frame structure comprising: a frame having upper and lower halves and a living hinge disposed etween, the upper and lower halves configured to cooperate with a low profile ulate filter; the upper and lower halves r comprising a snap joint for engaging the upper half to the lower half when the device is folded at the living hinge to maintain the structure in an assembled configuration; wherein the frame has an open plenum configuration in which a filter plenum is held in an open position, and a negative pressure check configuration in which a portion of the upper half seals against a portion of the lower half to facilitate seal and leak tightness of a facepiece associated with the filter structure.
- 2. The single piece filter frame structure of claim 1, the lower half including a breathing tube for connecting to an associated port of a ator; the lower half further including a fulcrum bar to engage a cantilever beam of the upper half to bias the upper and lower halves apart when the device is in the assembled configuration.
- 3. The single piece filter frame structure of claim 2, wherein a force required to configure the frame in the negative pressure check configuration is controllable by controlling a cross section of the cantilever beam, a length of the cantilever beam, a position of the fulcrum bar, and a position of the snap joint.
- 4. The single piece filter frame structure of claim 3, n at least one of the cross section of the cantilever beam, the length of the cantilever beam, and the position of the fulcrum bar are selected to minimize the force ed to configure the frame in the negative pressure check configuration to minimize translation of the force through the facepiece.
- 5. The single piece filter frame structure of claim 2, wherein when the structure is in the assembled configuration, a force applied to an outer surface of the upper half moves the upper half toward the lower half in opposition to the bias of the fulcrum bar and cantilever beam so that the upper half seals against the ing tube.
- 6. The single piece filter frame structure of claim 5, the upper half further comprising a soft seal to facilitate sealing of the upper half against the breathing tube.
- 7. The single piece filter frame structure of claim 1, n when the structure is in the assembled configuration the bias of the upper and lower halves serves to hold an open plenum between top and bottom media halves.
- 8. The single piece filter frame structure of claim 1, wherein the frame comprises a polymer.
- 9. A filter structure sing: a frame having an upper portion and a lower portion, the upper and lower portions configured to cooperate with a low profile ulate filter, the upper and lower portions including a fulcrum bar and cantilever beam combination to bias the upper and lower portions apart; wherein the frame is selectively movable between an open plenum configuration and a negative re check configuration; wherein when the frame is in the open plenum configuration, a filter plenum is held in an open position, and wherein when the frame is in the a negative pressure check configuration, the upper portion seals against the lower portion to facilitate seal and leak tightness of a facepiece associated with the filter structure.
- 10. The filter structure of claim 9, n the upper n and the lower n are formed as separate pieces.
- 11. The filter ure of claim 9, wherein the upper and lower portions are connected by at least one of a snap joint, a sonic weld, a permanent joining arrangement and a semi-permanent joining arrangement.
- 12. The filter structure of claim 9, the lower portion including a breathing tube for connecting to an associated port of a respirator; the upper and lower halves further comprising a snap joint for ng the upper half to the lower half when the device is in an assembled configuration, the snap joint to maintain the structure in the assembled configuration;.
- 13. The filter structure of claim 12, wherein a force required to configure the plenum closed is controllable by controlling a cross section of the cantilever beam, a length of the cantilever beam, a on of the fulcrum bar, and a position of the snap joint.
- 14. The filter structure of claim 13, wherein at least one of the cross section of the cantilever beam, the length of the cantilever beam, and the position of the fulcrum bar are selected to ze the force required to configure the plenum closed to minimize translation of the force through the ece.
- 15. The filter structure of claim 12, wherein a force applied to an outer surface of the upper portion moves the upper n toward the lower portion in opposition to the bias of the fulcrum bar and cantilever beam so that the upper portion seals against the breathing tube.
- 16. The filter structure of claim 15, the upper portion further comprising a soft seal to facilitate sealing of the upper portion against the breathing tube.
- 17. A filter arrangement comprising: a frame having upper and lower halves and a living hinge disposed therebetween; a low profile particulate filter positioned to ate with the upper and lower halves; wherein the lower half of the frame includes a breathing tube for connecting to an associated port of a respirator; wherein the frame further ses a snap joint for engaging the upper half and the lower half when the device is folded at the living hinge, the snap joint to maintain the structure in an assembled configuration; wherein the lower half further includes a fulcrum bar to engage a cantilever beam of the upper half to bias the upper and lower halves apart when the device is in the assembled configuration; and wherein when the ure is in the assembled configuration, a force applied to an outer surface of the upper half moves the upper half toward the lower half in opposition to the bias of the fulcrum bar and cantilever beam so that the upper half seals against the breathing tube.
- 18. The filter arrangement of claim 17, wherein the bias holds a plenum of the low profile particulate filter open.
- 19. The filter arrangement of claim 17, wherein a force required to seal the upper half against the breathing tube is controllable by controlling a cross section of the ever beam, a length of the cantilever beam, a position of the fulcrum bar, and a position of the snap joint.
- 20. The filter structure of claim 17, wherein at least one of the cross section of the cantilever beam, the length of the ever beam, and the position of the fulcrum bar are selected to minimize the force required to configure the plenum closed to minimize translation of the force through a ece associated with the filter structure.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201161434761P | 2011-01-20 | 2011-01-20 | |
US61/434,761 | 2011-01-20 | ||
PCT/US2012/021954 WO2012100116A1 (en) | 2011-01-20 | 2012-01-20 | Low profile frame for a filter incorporating a negative pressure check mechanism |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ612740A NZ612740A (en) | 2014-11-28 |
NZ612740B2 true NZ612740B2 (en) | 2015-03-03 |
Family
ID=
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