Two-part structural support member for a harness for breathing apparatus

0001The present invention relates to a structural support member for a harness for breathing apparatus, in particular, a structural support member comprising first and second attached parts defining therebetween a housing for retaining a components.

0002Self-contained breathing apparatus (SCBA) harnesses comprise a structural support member for supporting a cylinder of breathable gas and a pair of shoulder straps and a belt to facilitate the carrying of the structural support member on the back of a user. The structural support member is provided with a valve towards its lower end and a retaining strap at its upper end. In use, a cylinder of breathable gas is attached to the valve and is further secured to the structural support member by means of the retaining strap which is made to pass around an upper portion of the cylinder. A number of flexible hoses extended from the valve to the shoulder straps so that breathing apparatus worn by the user may be conveniently connected thereto.

0003In addition to a gas-cylinder valve, a number of other components that are operatively associated with the breathing apparatus may be mounted to the structural support member. These may include, for example, a battery, a pressure transducer and a radio telemetry device.

0004The gas-cylinder reducer valve is usually mounted on a lower front portion of the structural support member and a battery, pressure transducer and radio telemetry device may be mounted on the rear of the structural support member. The mounting is usually accomplished by known fixing mechanisms such as snap-fit, adhesive, screws, nuts and bolts.

0005<patcit id="pcit0001" dnum="EP0903162A"><text>EP0903162</text></patcit> discloses a backframe for a self contained breathing apparatus (SCBA) formed of a molded shell having some depth, and a closure plate fixed to the shell to provide an enclosed volume. The molded shell with the closure plate provides a water and dust-resistant enclosure for control components of the SCBA.

0006Document <patcit id="pcit0002" dnum="US4049164A"><text>US 4 049 164 A</text></patcit> discloses a structural support member for a harness for breathing apparatus according to the pre-amble of claim 1.

0007The above described methods of mounting are satisfactory but the level of protection offered to the components is somewhat limited. The assembly method can also sometimes be time-consuming.

0008It is therefore desirable to provide a structural support member to which components can be easily mounted. Further, it is desirable to provide a structural support member which offers protection to the components.

0009The invention is defined in the attached independent claim, to which reference should now be made. Further, optional features may be found in the sub-claims appended thereto.

0010According to a first aspect of the present invention there is provided a structural support member for a harness for breathing apparatus, the structural support member being generally elongate and arranged in use to support a cylinder of breathable gas and one or more components operatively associated with the breathing apparatus, wherein the structural support member comprises first and second parts defining therebetween a housing within a lower portion of the structural support member arranged to protectively retain a reducer valve for the cylinder to which the cylinder can be attached, wherein the first and second parts are arranged to be assembled around the reducer valve.

0011The first and second parts may be attached along a longitudinal extent which may be an axis which may be substantially coincident with a longitudinal centreline of the structural support member.

0012Preferably the structural support member comprises: a frame comprising: a lower portion arranged in use to support a first end of a cylinder; an upper portion arranged in use to support a second opposed end of the cylinder; and first and second side limbs coupling the upper and lower portion and defining a void therebetween in a substantially central region of the frame.

0013The void may be substantially longitudinally coextensive with the gas-cylinder that is to be mounted on the back frame. The void may be substantially transversely coextensive with the gas-cylinder that is to be mounted on the back frame.

0014Preferably the void is arranged such that in use it can accommodate a portion of a wearer's back/spine when the wearer bends his back/spine. The void may be delimited by the upper portion, the lower portion and the first and second limbs. The first and second side limbs may be disposed either side of the gas-cylinder that is to be mounted to the back frame.

0015In a preferred embodiment at least one of the first and second side limbs has a guide channel for accommodating a flexible conduit.

0016The upper portion may comprise a yoke that is detachably attached to the back frame. The yoke may be detachably attached to the first and second side limbs.

0017In a preferred arrangement the first part comprises the first side limb and the second part comprises the second side limb.

0018The longitudinal axis along which the first and second parts are attached may be substantially coincident with the longitudinal centreline of the lower portion.

0019According to another aspect of the present invention there is provided a structural support member for a harness for breathing apparatus, the structural support member being generally elongate and arranged in use to support a cylinder of breathable gas and one or more components operatively associated with the breathing apparatus, wherein the structural support member comprises first and second parts substantially attached along a plane that is perpendicular to the plane of the structural support member and defining therebetween a housing for retaining one or more of the components.

0020According to a further aspect of the present invention there is provided a harness for breathing apparatus comprising the structural support member according to any preceding claim

0021The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive.

0022Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="none"><li><figref idref="f0001">Figure 1</figref> schematically shows a harness for breathing apparatus comprising a back frame according to an embodiment of the present invention;</li><li><figref idref="f0002">Figure 2</figref> schematically shows the harness of <figref idref="f0001">Figure 1</figref> with a gas-cylinder mounted on the back frame;</li><li><figref idref="f0003">Figure 3</figref> schematically shows a front view of the back frame shown in <figref idref="f0001">Figure 1</figref>;</li><li><figref idref="f0004">Figure 4</figref> schematically shows a yoke portion of the back frame of <figref idref="f0003">Figure 3</figref>;</li><li><figref idref="f0005">Figure 5</figref> schematically shows a rear view of the back frame shown in <figref idref="f0003">Figure 3</figref>;</li><li><figref idref="f0006">Figure 6</figref> schematically shows the frame of <figref idref="f0003">Figure 3</figref> in a disassembled state;</li><li><figref idref="f0007">Figure 7</figref> schematically shows first and second parts of the back frame being assembled around a gas-cylinder reducer valve;</li><li><figref idref="f0008">Figure 8</figref> schematically shows the yoke portion being attached to first and second parts of the back frame;</li><li><figref idref="f0009">Figure 9</figref> schematically shows a perspective view of the back frame of <figref idref="f0001">Figure 1</figref>;</li><li><figref idref="f0010">Figure 10</figref> schematically shows a rear view the back frame of <figref idref="f0001">Figure 1</figref> with flexible conduits located in guide channels; and</li><li><figref idref="f0011">Figure 11</figref> schematically shows a front view of a back plate for a harness for breathing apparatus according to a second embodiment of the present invention; and</li><li><figref idref="f0012">Figure 12</figref> schematically shows a rear view of the back plate of <figref idref="f0011">Figure 11</figref>.</li></ul>

0023Turing to <figref idref="f0001"><b>Figure 1</b></figref><b>,</b> this shows a harness 100 for breathing apparatus comprising a structural support member in the form of a back frame 10. The harness 100 comprises left and right shoulder straps 110, 120, a waist belt 130 and a gas-cylinder retaining strap 136. A gas-cylinder reducer valve 140 is mounted within a lower portion 11 of the back frame 10. A high-pressure hose 150 and medium-pressure hose 152 extend from the reducer valve 140, along the back frame 10 to positions on the left and right shoulder straps 110, 120.

0024As shown in <figref idref="f0002"><b>Figure 2</b></figref><b>,</b> in use a gas-cylinder 1 is mounted to the back frame 10 of the harness 100. A first end 2 of the gas-cylinder is supported by a lower portion 11 of the back frame 10 and a second end 3 of the gas-cylinder is supported by an upper portion of the back frame 10. The first end 2 of the gas-cylinder is attached to the reducer valve 140 that is mounted within a lower portion of the back frame 10 and the second end 3 is strapped to the upper portion of the back frame using the retaining strap 136.

0025<figref idref="f0003"><b>Figure 3</b></figref> shows a front view of the back frame 10 alone. The back frame 10 comprises a first part 20 a second part 30 and a yoke 40. The first and second parts 20, 30 are substantially the same but are mirror images of one another. They are connected together towards the lower portion of the back frame along a longitudinal axis 12 of the back frame 10 which is coincident with the centre line of the back frame 10. The first and second parts 20, 30 are connected together towards the upper portion of the back frame 10 by the yoke 40.

0026The first part 20 comprises a first lower portion 22 and a first upper portion 24 that make up the lower portion 11 of the back frame 10. A first side limb 26 extends longitudinally and connects the first lower portion 22 to the first upper portion 24. The first part 20 further comprises a first side flange 28 which comprises two fixing portions 27, 29 to which the left shoulder strap 110 and the waist strap 130 can be attached.

0027The second part 30 comprises a second lower portion 32 and a second upper portion 34. A second side limb 36 extends longitudinally and connects the second lower portion 32 to the second upper portion 34. The second part 30 further comprises a second side flange 38 which comprises two fixing portions 37, 39 to which the right shoulder strap 120 and the waist strap 130 can be attached.

0028The first and second side limbs 26, 36 define a void 14 in a central region of the back frame 10. The void 14 is delimited by the first and second side limbs 26, 26, the lower portion 11 of the back frame 10 and the yoke 40 (or upper portion of the back frame 10). The void 14 extends longitudinally along, and transversely across, the majority, or at least a substantial portion, of the back frame 10.

0029With reference to <figref idref="f0004"><b>Figure 4</b></figref><b>,</b> the yoke 40 of the back frame 10 comprises first and second attachment portions 42, 44 for attaching the yoke 40 to the first and second parts 20, 30 respectively. The first and second attachment portions 42, 44 each comprise a tongue 41, 43 (described in more detail below). The yoke 40 further includes left and right shoulder strap fixing portions 46, 48 to which the left and right shoulder straps 110, 120 can be attached.

0030<figref idref="f0005"><b>Figure 5</b></figref> shows a rear view of the back plate 10 alone. The first side limb 26 comprises a first guide channel 25 and the second side limb 36 comprises a second guide channel 35. The channels 25, 35 are arranged to accommodate and retain the high-pressure hose 150 and the medium pressure hose 152 respectively. The guide channels 25, 35 are shaped with projections within and along their length that are arranged to retain flexible conduits within the channels. However, as will be readily apparent to one skilled in the art, other means for retaining flexible conduits within the channels are possible.

0031<figref idref="f0006"><b>Figure 6</b></figref> shows the back frame 10 in a disassembled state. As can be seen, the first part 20, second part 30 and yoke 40 are completely separable. The first and second parts 20, 30 are attached along a longitudinal axis 12 of the back frame 10. The first part 20 comprises two protrusions 21 that, upon assembly, are inserted into two holes in the second part 31 (not shown). A nut and bolt (not shown) are used to hold a first lower portion 22 to a second lower portion 32. The yoke 40 can be snap-fitted to the first and second upper portions 24, 34 (described in more detail later). A housing for the reducer valve 140 is defined between the first and second parts 20, 30 in order to retain the reducer valve 140 on the back frame 10.

0032In this embodiment the longitudinal extent along which the first and second parts 20, 30 are attached is a longitudinal axis 12 which is coincident with a longitudinal centre line of the back frame. However, as will be readily apparent to one skilled in the art, the longitudinal extent of attachment may be orientated at 45°, or any other suitable angle, to the longitudinal axis.

0033Referring now to <figref idref="f0007"><b>Figure 7</b></figref><b>,</b> the first lower portion 22 of the first part 20 comprises a first recess 23 and the second lower portion 32 of the second part 30 comprises a second recess 33. During assembly of the harness 100 first and second lower portions 22, 32 are assembled around the reducer 140 such that it is housed within both the first recess 23 and the second recess 33. After the first and second lower portions 22, 32 have been fixed together using a nut and bolt (or other fixing device) the reducer is retained within the lower portion 11 of the back frame 11. The housing defined by the first and second recesses 23, 33 of the first and second parts 20, 30 protect any delicate components of the reducer valve 140 and also reduce the overall profile of the harness 100 because a portion of the reducer 140 is located within the back frame 10. The reducer 140 is also fixed to the back frame 10 without the need for additional fixing components.

0034After the first and second parts 20, 30 have been attached together by the first and second lower portions 22, 32, the yoke 40 is attached between the first and second upper portions 24, 34. As shown in <figref idref="f0008"><b>Figure 8</b></figref><b>,</b> this is done by slotting the tongues 41, 43 of the first and second attachment portions 42, 44 of the yoke, into first and second grooves 24a, 34a (<figref idref="f0007">Figure 7</figref>) provided in the first and second upper portions 22, 32 of the first and second parts 20, 30. This is a snap-fit-type connection that can be made without the need for tools.

0035The assembled back frame 10 having a reducer valve 140 housed within the lower portion 11 can be seen in <figref idref="f0009"><b>Figure 9</b></figref><b>.</b> The reducer valve 140 comprises a cylinder connection portion 142 that protrudes from the housing such that a gas-cylinder can be attached thereto.

0036With reference to <figref idref="f0010"><b>Figure 10</b></figref><b>,</b> after the back frame 10 has been assembled, a high-pressure hose 150 and a medium-pressure hose 152 are attached to the reducer valve 140. The high-pressure hose 150 is located in the first guide channel 25 of the first side limb 20 and the medium-pressure hose 152 is located in the second guide channel 35 of the second side limb 30. The hoses 25, 35 cross to the front side of the back frame 10 in the region of the yoke 40, cross over, and are positioned on the shoulder straps 110, 120 (<figref idref="f0001">Figure 1</figref>).

0037Referring back to <figref idref="f0001">Figure 1</figref>, assembly of the harness 100 can be completed by attaching the left and right shoulder straps 110, 120, the waist strap 130 and the cylinder retaining strap 136. The harness 100 is particularly light due to the large void 14 that occupies a substantial area of the back frame 10. As can be seen from <figref idref="f0002">Figure 2</figref>, the void 14 is substantially longitudinally and transversely coextensive with the gas cylinder 1. The first and second side limbs 26, 36 are spaced either side of the gas-cylinder.

0038The harness 100 is also comfortable for a wearer. When a user wears the harness 100 on his or her back, the back frame 10 only contacts the user at a lower region and an upper region. When a user bends over his back/spine bends into the void 14. This cannot occur with conventional harnesses 100. With conventional harnesses a user's back is forced against a back plate when the user bends over, which can be uncomfortable.

0039Further, because a user's spine/back can be accommodated in the void, the overall profile of the user including the harness is smaller. This makes crawling and climbing through small spaces easier.

0040In a further embodiment and as shown in <figref idref="f0011"><b>Figures 11</b></figref><b>and</b><figref idref="f0012"><b>12</b></figref><b>,</b> the structural support member comprises a back plate 10 as opposed to a frame. The back plate 10 comprises first and second parts 20, 30 that are attached along a longitudinal axis 11 of the back plate 10 that is the centre line of the back plate 10. The first part 20 comprises an upper left shoulder strap fixing portion 46 and a lower left shoulder strap fixing portion 27. The second part 30 comprises an upper right shoulder strap fixing portion 48 and a lower right shoulder strap fixing portion 37. A central waist belt fixing portion 15 is also provided.

0041The rear side of the back plate (<figref idref="f0012">Figure 12</figref>) comprises a housing 50 for a battery 60, a pressure transducer 70, and a radio telemetry device 80 (collectively known as components operatively associated with the breathing apparatus). The components 60, 70, 80 are retained within the housing which is defined by the first and second parts 20, 30 of the back plate 10. During assembly of the back plate 10, the first and second parts 20, 30 are assembled around the components 60, 70, 80 so as to retain them within the back plate. This arrangement protects the components 60, 70, 80 and allows them to be fixed to the back plate without any additional fixtures. The first and second parts 20, 30 can be fixed together using any known mechanisms such as nuts and bolts, snap-fit, adhesive, for example.

0042As will be readily apparent to one skilled in the art, any components that need to be fixed to the structural support member may be retained in a housing defined by the two separate parts.