Self-contained breathing apparatus, components thereof and battery compartment thereof

Abstract

The invention relates to a self-contained breathing apparatus, components thereof and a battery compartment thereof. A digital display device is provided. For example, a digital display device may include a rigid housing, a compressible layer over at least a portion of the rigid housing, and a rigid cover. The rigid housing defines an interior chamber and an opening to the battery compartment. The battery compartment is adapted to receive the battery at a position where a longitudinal axis of the battery is substantially parallel to the opening. The compressible layer defines an opening that shares a boundary with the opening to the battery compartment. The rigid cover is selectively attachable to the rigid housing such that when the rigid cover is selectively attached to the rigid housing, at least a portion of the compressible layer is sandwiched between the rigid cover and the rigid housing and at least a portion of the rigid cover at least partially compresses a corresponding portion of the compressible layer.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to self-contained breathing apparatus, and more particularly to a battery compartment for a self-contained breathing apparatus. Background Art

[0002] A self-contained breathing apparatus ("SCBA") is a device used to provide air to a user when the ambient air is dangerous for the user to breathe. Such an environment may be considered an "immediate danger to life and health" or "IDLH" environment. Firefighters or other first responders often use SCBAs when in hazardous environments. Applicants have identified a number of deficiencies and problems associated with conventional SCBAs. Through applied effort, creativity, and innovation, many of these identified problems have been solved by developing solutions that are included in embodiments of the present invention, many examples of which are described in detail herein. Summary of the invention

[0003] Various embodiments described herein relate to SCBAs, components of SCBAs, and battery compartments for SCBAs and components of SCBAs.

[0004] According to various embodiments of the present disclosure, a digital display device is provided. In some embodiments, the digital display device includes a rigid shell, a compressible layer on at least a portion of the rigid shell, and a rigid cover. The rigid shell defines an internal chamber and an opening to a battery compartment. The battery compartment is separated from the internal chamber and is suitable for receiving a battery in a position where the longitudinal axis of the battery is substantially parallel to the opening to the battery compartment. The compressible layer defines an opening that shares a boundary (coterminous) with the opening to the battery compartment. The rigid cover has an inner side and an opposite outer side, and can be selectively attached to the rigid shell, so that when the rigid cover is selectively attached to the rigid shell, at least a portion of the compressible layer is sandwiched between the rigid cover and the rigid shell, and at least a portion of the rigid cover at least partially compresses the corresponding portion of the compressible layer.

[0005] In some embodiments, the rigid cover includes at least two opposing claws that protrude from the inner side and are suitable for holding the battery in an appropriate position therebetween so that the longitudinal axis of the battery is substantially parallel to the inner side for insertion into the battery compartment when the rigid cover is selectively attached to the rigid shell.

[0006] In some embodiments, the at least two opposing jaws each have a curved medialedge adapted to contact an outer wall of the battery to retain the battery.

[0007] In some embodiments, the at least two opposing prongs include two prongs on a first side of a midline of the rigid cover and one prong on an opposing second side of the midline of the rigid cover.

[0008] In some embodiments, the rigid cover defines a fastener hole for inserting a fastener to fix the rigid cover to the rigid shell, and the rigid cover also includes a ridge protruding from the inside and surrounding the fastener hole. When the rigid cover is selectively attached to the rigid shell, the ridge at least partially compresses the corresponding portion of the compressible layer.

[0009] In some embodiments, the fastener comprises a screw.

[0010] In some embodiments, the compressible layer comprises an overmolded layer over the rigid shell.

[0011] In some embodiments, the rigid cover includes a pull ring pivotally attached to an outer side of the rigid cover.

[0012] In some embodiments, the digital display device comprises a display device of the self-contained breathing apparatus for displaying an air pressure reading.

[0013] According to various embodiments of the present disclosure, a self-contained breathing apparatus is provided. In some embodiments, the self-contained breathing apparatus includes an air tank, a mask connected to the air tank via a pipeline, and a digital display device for displaying the air pressure reading of the air tank. The digital display device includes a rigid shell, a compressible layer on at least a portion of the rigid shell, and a rigid cover. The rigid shell defines an internal chamber and an opening to a battery compartment. The battery compartment is separated from the internal chamber and is suitable for receiving a battery in a position where the longitudinal axis of the battery is substantially parallel to the opening to the battery compartment. The compressible layer defines an opening that shares a boundary with the opening to the battery compartment. The rigid cover has an inner side and an opposite outer side, and can be selectively attached to the rigid shell, so that when the rigid cover is selectively attached to the rigid shell, at least a portion of the compressible layer is sandwiched between the rigid cover and the rigid shell, and at least a portion of the rigid cover at least partially compresses the corresponding portion of the compressible layer.

[0014] The foregoing illustrative summary as well as other exemplary objects and / or advantages of the present disclosure, and the manner in which the same are accomplished, are further explained in the following detailed description and its accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The description of the illustrative embodiments may be read in conjunction with the accompanying drawings. It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale unless otherwise described. For example, the dimensions of some elements may be exaggerated relative to other elements unless otherwise described. Embodiments incorporating the teachings of the present disclosure are shown and described in conjunction with the drawings presented herein, in which:

[0016] Figure 1 An example SCBA according to an exemplary embodiment of the present disclosure is shown;

[0017] Figure 2A and 2B The exemplary embodiment according to the present disclosure is shown Figure 1 An example digital display unit of an example SCBA;

[0018] Figure 3 According to an exemplary embodiment of the present disclosure Figure 2A and 2B A partially exploded view of an example digital display;

[0019] Figure 4A and 4B The exemplary embodiment according to the present disclosure is shown Figure 2A and 2B an example battery compartment cover of an example digital display; and

[0020] Figure 5 According to an exemplary embodiment of the present disclosure Figure 2A and 2B A cross-sectional view of an example digital display. DETAILED DESCRIPTION

[0021] Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments of the present disclosure are shown. Indeed, these disclosures may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout.

[0022] As used herein, terms such as "front," "rear," "top," "bottom," "left," "right," and the like are used for explanatory purposes in the examples provided below to describe the relative positions of certain components or portions of components. Additionally, as will be apparent to one of ordinary skill in the art from this disclosure, the terms "substantially" and "approximately" indicate that the referenced element or associated description is accurate within applicable engineering tolerances.

[0023] As used herein, the term "comprising" means including but not limited to and should be interpreted in the manner in which it is commonly used in a patent context. The use of broader terms, such as "comprising," "including," and "having," should be understood to provide support for narrower terms, such as "consisting of," "consisting essentially of," and "consisting essentially of.

[0024] The phrases "in one embodiment," "according to one embodiment," "in some embodiments," etc. generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure (importantly, such phrases do not necessarily refer to the same embodiment).

[0025] The phrases "in one example," "according to an example," "in some examples," etc. generally mean that a particular feature, structure, or characteristic following the phrase may be included in at least one example of the present disclosure, and may be included in more than one example of the present disclosure (importantly, such phrases do not necessarily refer to the same example).

[0026] If the specification states that a component or feature "may", "could", "would", "should", "will", "preferably", "likely", "typically", "optionally / optionally", "for example", "as an example", "in some examples", "often", or "might" (or other such language) be included or have a property, then the particular component or feature need not be included or have that property. In some examples, such components or features may optionally be included, or such components or features may be excluded.

[0027] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0028] The terms "electronically coupled," "electronically coupled," "electronically coupled," "communicating with," "electronically communicating with," or "connected" in this disclosure refer to two or more elements or components that are connected by wired means and / or wireless means such that signals, voltage / current, data and / or information can be sent to and / or received from these elements or components.

[0029] The term "component" may refer to an article, device, or equipment that may include one or more surfaces, parts, layers, and / or elements. For example, an exemplary component may include one or more substrates that may provide (one or more) underlying layers for the component and may include one or more elements that may form part of the substrate and / or be disposed on top of the substrate. In the present disclosure, the term "element" may refer to an article, device, or equipment that may provide one or more functions.

[0030] Some existing SCBAs include a digital display unit (which may also be referred to as a digital display device). Such a digital display unit displays the air pressure in the cylinder of the SCBA and may interface with a head-up display (HUD) mounted in the mask of the SCBA so that the HUD displays information about the air pressure in the cylinder.

[0031] Existing battery compartment designs used in various applications, such as in digital display units of SCBAs, have certain technical problems. For example, in some existing battery compartments, water and dust may leak into the battery compartment (and then possibly into the internal compartment that houses the electronic components (e.g., processor, air pressure sensor, etc.)) due to poor sealing.

[0032] To address the challenges and limitations associated with SCBAs, various examples of the present disclosure may be provided. For example, various examples of the present disclosure may provide example SCBAs, components for SCBAs (such as digital display units), and battery compartments for SCBAs and components of SCBAs. Although embodiments of the present disclosure are described herein in relation to digital display units for SCBAs, embodiments of the present disclosure may be used with other battery-powered components of SCBAs and other non-SCBA battery-powered devices.

[0033] Various embodiments of the present disclosure provide an exemplary digital display unit for firefighting and other wet and / or harsh (e.g., dirty or contaminated) environments having a sealed battery compartment to reduce the possibility of leakage into the battery compartment and the internal cavity of the device.

[0034] In various embodiments, the battery is positioned so that the force of the spring holding the battery in place (and providing one of the electrical contacts) does not apply an outward force to the battery compartment cover.

[0035] In various embodiments, the digital display unit has a compressible layer, and the battery compartment cover is securely attached against the compressible layer to provide a seal that helps prevent the intrusion of water and other contaminants.

[0036] In various embodiments, the battery compartment cover has a three-claw structure to hold the battery in a fixed position for easy insertion and removal.

[0037] Reference now Figure 1 , an example SCBA 100 is shown according to various embodiments of the present disclosure. Figure 1As shown, in some embodiments, the SCBA 100 includes a mask 102 (in which a heads-up display (not shown) may be mounted) and a harness 106. The harness 106 includes a back frame 108 that holds a cylinder or air tank 110. The harness 106 includes shoulder straps 112 and a waist belt 114 that enable a user to wear the SCBA 100. Breathable air is provided from the air tank 110 via an air hose 116, which is connected to the air tank 110 via a first stage regulator 103 and to the mask 102 via a second stage regulator 104. Information about the amount of breathable air in the air tank 110 is provided to the user via a separate analog pressure gauge (not shown) or a digital display unit 120 (which may also include an analog pressure gauge), which is connected to the air tank 110 via an air hose 118. The digital display unit 120 is battery powered and contains sensitive electronic components and should therefore be protected from infiltration of water, dust, etc.

[0038] Although the description herein provides an example SCBA 100 and a digital display unit 120, it should be noted that the scope of the present disclosure is not limited to the description herein. In some examples, the example SCBA 100 and / or the digital display unit 120 according to the present disclosure may be in other forms. In some examples, the example SCBA 100 and / or the digital display unit 120 may include one or more additional and / or alternative elements, and / or may be configured differently than shown in the figures.

[0039] Now refer to Figure 2A-2B , which shows Figure 1 1. An exemplary digital display unit 120 of an exemplary SCBA 100 is shown in FIG. Figure 2A-2B The exemplary digital display unit 120 includes a housing 122 that defines an internal chamber (internal chamber 164 at Figure 5 1). The housing 122 is constructed of any suitable rigid, durable material or combination of materials, including any suitable plastic, such as polycarbonate. The front side of the digital display unit 120 has a digital display 124 (e.g., an LCD display) and an analog pressure gauge 126. In some embodiments, the digital display 124 displays information such as the air pressure within the air tank 110 and other information. The rear side of the digital display unit 120 has a battery compartment cover 130 and a compressible layer 123 on a portion of the housing 122. Figure 2A and 2BIn some embodiments, the battery compartment cover 130 is fixed in place to cover the opening to the battery compartment. In some embodiments, the compressible layer 123 is overmolded on a portion of the housing 122. In some embodiments, the compressible layer 123 includes rubber, synthetic rubber, etc. In some embodiments, when the battery compartment cover 130 is selectively attached to the housing 122, at least a portion of the compressible layer 123 is sandwiched between the battery compartment cover 130 and the housing 122, and at least a portion of the battery compartment cover 130 at least partially compresses a corresponding portion of the compressible layer 123 to provide a seal.

[0040] In the exemplary embodiment shown, a plurality of holes 128 are defined on the rear side of the digital display unit 120 to enable a user or other person to hear any sounds (e.g., alarms) emitted by the digital display unit 120, such as sounds that may be generated by a personal alarm safety system (PASS) function of the digital display unit 120. The digital display unit 120 is connected to the air hose 118 to enable the digital display unit 120 to detect the air pressure within the air tank 110.

[0041] Reference now Figure 3 , showing the digital display unit 120, the battery compartment cover 130 and the battery 146 removed. Figure 3 As shown, with the battery compartment cover 130 removed, a circular recess 154 is defined in the housing 122 (which is also covered by the compressible layer 123) to recessedly receive the circular battery compartment cover 130. In the exemplary embodiment shown, the battery compartment 150 is formed by a semi-cylindrical wall 152 to receive the cylindrical battery 146. Figure 3 As shown, the arrangement of the battery compartment is such that the battery is received by the battery compartment at a position where the longitudinal axis of the battery is substantially parallel to the opening to the battery compartment. In some existing SCBA digital display units, the battery is received by the battery compartment with the longitudinal axis of the battery being perpendicular to the opening to the battery compartment, in which case the spring pushes the battery against the battery compartment cover, which may adversely affect the seal between the battery compartment cover and the housing.

[0042] In the exemplary embodiment shown, the spring 158 helps hold the battery 146 in the battery compartment 150 and serves as a negative electrical contact. A positive electrical contact (not shown) is located on the opposite end of the battery compartment 150. In some embodiments, the spring 158 is constructed of a wire having a diameter greater than that typically used to hold similarly sized batteries, so as to provide a stronger spring force to push the battery 146 against the positive electrical contact and thereby provide a better hold of the battery 146 in the battery compartment 150. In an exemplary embodiment, the spring 158 is constructed of a wire having a diameter of 0.8 millimeters. In various embodiments, where the spring 158 and the positive electrical contact protrude through the openings of the respective end walls of the battery compartment 150, a sealant (e.g., an adhesive sealant) is placed around the opening to help prevent any contaminants that enter the battery compartment 150 from also entering the interior chamber 164.

[0043] As seen in the exemplary embodiment shown, the battery compartment cover 130 includes a pull ring 132 that is pivotally attached to the outside of the battery compartment cover 130 via two attachment points 134 to enable easy removal of the battery compartment cover 130 to replace the battery. In the exemplary embodiment shown, the battery compartment cover 130 defines a fastener hole 142 for inserting a fastener 140 (such as, but not limited to, a screw or bolt) to secure the battery compartment cover 130 to the housing 122. Corresponding fastener holes 156 are defined in the compressible layer 123 and in the lower portion of the housing 122 to receive the fastener 140. In embodiments where the fastener is an externally threaded fastener such as a screw or bolt, the corresponding fastener hole defined in the housing will be internally threaded.

[0044] Reference now Figure 4A and 4B , and the battery compartment cover 130 is shown from the inside without the battery 146 and with the battery 146 held by the battery compartment cover 130, respectively. Figure 4A and 4B As shown, the battery compartment cover 130 includes three claws 138 protruding from the inner side thereof for holding the battery 146 in place therebetween so that the longitudinal axis of the battery is substantially parallel to the inner side of the battery compartment cover 130 for insertion into the battery compartment 150 when the battery compartment cover 130 is selectively attached to the housing 122. In the illustrated embodiment, there are two claws on a first side of the centerline of the battery compartment cover 130 and one claw on an opposite second side of the centerline of the battery compartment cover 130. Figure 3As shown, the opposing long edges of the battery compartment wall 152 define three notches 162, namely two notches on the top edge and one notch on the bottom edge. When the battery compartment cover 130 is selectively attached to the housing 122, these notches 162 align with and receive portions of corresponding claws 138 of the battery compartment cover 130. Thus, the alignment of the notches and claws ensures that the battery compartment cover 130 is properly positioned to place the negative terminal of the battery 146 against the spring 158 and the positive terminal of the battery 146 against the positive electrical contact (not shown), and to properly align the fastener holes 142 in the battery compartment cover 130 with the corresponding fastener holes 156 in the housing 122.

[0045] like Figure 4A and 4B As shown, each claw 138 has a curved inner edge having substantially the same curvature as the outer wall of the battery 146, so as to contact the outer wall of the battery 146 to hold the battery 146 between the claws 138. In various embodiments, when the battery is held between the claws, the distal ends of the claws (and their curved edges) extend beyond a mid-plane that bisects the battery and is parallel to the battery compartment cover. Thus, when inserting or removing the battery between the claws, some force is required to move the battery past the distal ends of the claws, thereby helping to hold the battery between the claws. In alternative embodiments of the present disclosure, only two opposing claws may be used, or more than three claws may be used.

[0046] like Figure 4A and 4B As shown, the battery compartment cover 130 has a ridge 136 protruding from the inside along its perimeter. Similarly, the battery compartment cover 130 has a ridge 144 protruding from the inside and surrounding the fastener hole 142. When the battery compartment cover 130 is selectively attached to the housing 122, the peripheral ridge 136 and the fastener hole ridge 144 each at least partially compress a corresponding portion of the compressible layer 123 to provide a seal that helps prevent water and other contaminants from intruding around the edge of the battery compartment cover 130 and through the fastener hole 142, respectively.

[0047] Reference now Figure 5 , shows the digital display until along Figure 3 of Figure 5-Figure 5 The cross-sectional diagram of the line. Figure 5 As shown, a number of components are located within an interior chamber 164 formed by the housing 122. In the illustrated embodiment, such internal components include a printed circuit board 166 on which, for example, a processor may be mounted that controls the operation of the digital display unit 120, and a pressure sensor 160 for detecting the air pressure of the air in the air hose 118 connected to the air tank 110.

[0048] In some optional embodiments of the present invention, one or more parts of the shell may have two layers, defining a space between the two layers, in which insulating material (including but not limited to thermal insulation oil or flame retardant foam) is inserted to protect internal components from heat.

[0049] Although various embodiments according to the principles disclosed herein have been shown and described above, those skilled in the art may modify them without departing from the teachings of the present disclosure. The embodiments described herein are representative only and are not restrictive. Many variations, combinations and modifications are possible and are within the scope of the present disclosure. Alternative embodiments resulting from combining, integrating and / or omitting the features of the embodiments are also within the scope of the present disclosure. Therefore, the scope of protection is not limited by the description set forth above, but by the appended claims, which include all equivalents of the subject matter of the claims. Each claim is incorporated into the specification as further disclosure, and the claims are embodiments of the present disclosure. In addition, any of the advantages and features described above may relate to specific embodiments, but the application of these published claims should not be limited to processes and structures that achieve any or all of the above advantages or have any or all of the above features.

[0050] In addition, the section headings used herein are provided to be consistent with the recommendations in 37 CFR § 1.77 or to otherwise provide organizational cues. These headings should not limit or characterize the disclosure set forth in any claims that may be issued from this disclosure. For example, the description of the technology in the "background technology" should not be interpreted as an admission that certain technologies are prior art to any disclosure in this disclosure. "Summary of the invention" should also not be considered as a limiting characterization of the disclosure set forth in the issued claims. In addition, any reference to "disclosure" or "embodiment" in the singular form in this disclosure should not be used to prove that there is only a single novel point in this disclosure. Multiple embodiments of the disclosure may be set forth in accordance with the limitations of multiple claims issued from this disclosure, and such claims accordingly define the disclosure and its equivalents protected therefrom. In all cases, the scope of the claims should be considered on their own merits in accordance with this disclosure, but should not be constrained by the titles set forth herein.

[0051] In addition, without departing from the scope of the present disclosure, the systems, subsystems, devices, techniques and methods described and illustrated as discrete or separated in various embodiments can be combined or integrated with other systems, modules, technologies or methods. Other devices or components shown or discussed as being connected or communicating with each other can be indirectly connected through some intermediate devices or components, whether electrically, mechanically or otherwise. Other examples that can be changed, replaced and altered can be found and made by those skilled in the art without departing from the scope disclosed herein.

[0052] Benefiting from the teachings presented in the foregoing description and the related drawings, those skilled in the art to which these embodiments belong will think of many modifications and other embodiments of the present disclosure set forth herein. Although the drawings only show certain components of the devices and systems described herein, various other components may be used in combination with the components and structures disclosed herein. Therefore, it should be understood that the present disclosure is not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the appended claims. For example, various elements or components may be combined, rearranged or integrated in another system, or certain features may be omitted or not implemented. In addition, the steps in any of the above methods may not necessarily occur in the order depicted in the drawings, and in some cases, one or more of the depicted steps may occur substantially simultaneously, or may involve additional steps. Although specific terms are used herein, they are used only in a general and descriptive sense, not for the purpose of limitation.

Claims

1. A digital display device, comprising: a rigid housing defining an interior chamber and an opening to a battery compartment, the battery compartment being separate from the interior chamber and adapted to receive the battery in a position where a longitudinal axis of the battery is substantially parallel to the opening to the battery compartment; a compressible layer over at least a portion of the rigid shell, the compressible layer defining an opening that shares a boundary with the opening to the battery compartment; as well as A rigid cover having an inner side and an opposite outer side and capable of being selectively attached to the rigid shell, so that when the rigid cover is selectively attached to the rigid shell, at least a portion of the compressible layer is sandwiched between the rigid cover and the rigid shell, and at least a portion of the rigid cover at least partially compresses a corresponding portion of the compressible layer.

2. The digital display device according to claim 1, wherein: The rigid cover includes at least two opposing claws, which protrude from the inner side and are suitable for holding the battery in an appropriate position therebetween, so that the longitudinal axis of the battery is substantially parallel to the inner side so as to be inserted into the battery compartment when the rigid cover is selectively attached to the rigid shell.

3. The digital display device according to claim 2, wherein: The at least two opposing claws each have a curved inner edge adapted to contact an outer wall of the battery to retain the battery.

4. The digital display device according to claim 2, wherein: The at least two opposing prongs include two prongs on a first side of a centerline of the rigid cover and one prong on an opposing second side of the centerline of the rigid cover.

5. The digital display device according to claim 1, wherein: The rigid cover defines a fastener hole for inserting a fastener to secure the rigid cover to the rigid shell; and Wherein, the rigid cover further includes a ridge protruding from the inner side and surrounding the fastener hole, so that when the rigid cover is selectively attached to the rigid shell, the ridge at least partially compresses a corresponding portion of the compressible layer.

6. The digital display device according to claim 1, wherein: The rigid cover includes a pull ring pivotally attached to an outer side of the rigid cover.

7. A self-contained breathing apparatus comprising: Air tank; a face mask connected to the air tank via a tube; as well as A digital display device, used to display the air pressure reading of the air tank, the digital display device comprising: a rigid housing defining an interior chamber and an opening to a battery compartment, the battery compartment being separate from the interior chamber and adapted to receive the battery in a position where a longitudinal axis of the battery is substantially parallel to the opening to the battery compartment; a compressible layer over at least a portion of the rigid shell, the compressible layer defining an opening that shares a boundary with the opening to the battery compartment; A rigid cover having an inner side and an opposite outer side and capable of being selectively attached to the rigid shell, so that when the rigid cover is selectively attached to the rigid shell, at least a portion of the compressible layer is sandwiched between the rigid cover and the rigid shell, and at least a portion of the rigid cover at least partially compresses a corresponding portion of the compressible layer.

8. A self-contained breathing apparatus as claimed in claim 7, wherein: the rigid cover including at least two opposed claws projecting from the inner side and adapted to hold the battery in position therebetween such that a longitudinal axis of the battery is substantially parallel to the inner side for insertion into the battery compartment when the rigid cover is selectively attached to the rigid housing; and The at least two opposing claws each have a curved inner edge, and the curved inner edge is suitable for contacting the outer wall of the battery to hold the battery.

9. A self-contained breathing apparatus as claimed in claim 8, wherein: The at least two opposing prongs include two prongs on a first side of a centerline of the rigid cover and one prong on an opposing second side of the centerline of the rigid cover.

10. The self-contained breathing apparatus of claim 7, wherein: The rigid cover defines a fastener hole for inserting a fastener to secure the rigid cover to the rigid shell; and Wherein, the rigid cover further includes a ridge protruding from the inner side and surrounding the fastener hole, such that when the rigid cover is selectively attached to the rigid shell, the ridge at least partially compresses a corresponding portion of the compressible layer.

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