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

p-0002The 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.

p-0003Self-contained breathing apparatus (SOBA) 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 of 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.

p-0004In 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.

p-0005The 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.

p-0006The 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.

p-0007It 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.

p-0008According 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 for retaining one or more of the components.

p-0009The first and second parts may be attached along a longitudinal extend which may be an axis which may be substantially coincident with a longitudinal centreline of the structural support member.

p-0010In one embodiment the first and second parts define a housing within a lower portion of the structural support member arranged in use to retain a valve for the cylinder.

p-0011Preferably 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.

p-0012The 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.

p-0013Preferably 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.

p-0014In a preferred embodiment at least one of the first and second side limbs has a guide channel for accommodating a flexible conduit.

p-0015The 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.

p-0016In a preferred arrangement the first part comprises the first side limb and the second part comprises the second side limb.

p-0017The longitudinal axis along which the first and second parts are attached may be substantially coincident with the longitudinal centreline of the lower portion.

p-0018According 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.

p-0019According 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

p-0020The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive.

p-0021Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

p-0022<figref idrefs="DRAWINGS">FIG. 1</figref> schematically shows a harness for breathing apparatus comprising a back frame according to an embodiment of the present invention;

p-0023<figref idrefs="DRAWINGS">FIG. 2</figref> schematically shows the harness of <figref idrefs="DRAWINGS">FIG. 1</figref> with a gas-cylinder mounted on the back frame;

p-0024<figref idrefs="DRAWINGS">FIG. 3</figref> schematically shows a front view of the back frame shown in <figref idrefs="DRAWINGS">FIG. 1</figref>;

p-0025<figref idrefs="DRAWINGS">FIG. 4</figref> schematically shows a yoke portion of the back frame of <figref idrefs="DRAWINGS">FIG. 3</figref>;

p-0026<figref idrefs="DRAWINGS">FIG. 5</figref> schematically shows a rear view of the back frame shown in <figref idrefs="DRAWINGS">FIG. 3</figref>;

p-0027<figref idrefs="DRAWINGS">FIG. 6</figref> schematically shows the frame of <figref idrefs="DRAWINGS">FIG. 3</figref> in a disassembled state;

p-0028<figref idrefs="DRAWINGS">FIG. 7</figref> schematically shows first and second parts of the back frame being assembled around a gas-cylinder reducer valve;

p-0029<figref idrefs="DRAWINGS">FIG. 8</figref> schematically shows the yoke portion being attached to first and second parts of the back frame;

p-0030<figref idrefs="DRAWINGS">FIG. 9</figref> schematically shows a perspective view of the back frame of <figref idrefs="DRAWINGS">FIG. 1</figref>;

p-0031<figref idrefs="DRAWINGS">FIG. 10</figref> schematically shows a rear view the back frame of <figref idrefs="DRAWINGS">FIG. 1</figref> with flexible conduits located in guide channels; and

p-0032<figref idrefs="DRAWINGS">FIG. 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

p-0033<figref idrefs="DRAWINGS">FIG. 12</figref> schematically shows a rear view of the back plate of <figref idrefs="DRAWINGS">FIG. 11</figref>.

p-0034Turing to <figref idrefs="DRAWINGS">FIG. 1</figref>, this shows a harness <b>100</b> for breathing apparatus comprising a structural support member in the form of a back frame <b>10</b>. The harness <b>100</b> comprises left and right shoulder straps <b>110</b>, <b>120</b>, a waist belt <b>130</b> and a gas-cylinder retaining strap <b>136</b>. A gas-cylinder reducer valve <b>140</b> is mounted within a lower portion <b>11</b> of the back frame <b>10</b>. A high-pressure hose <b>150</b> and medium-pressure hose <b>152</b> extend from the reducer valve <b>140</b>, along the back frame <b>10</b> to positions on the left and right shoulder straps <b>110</b>, <b>120</b>.

p-0035As shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, in use a gas-cylinder <b>1</b> is mounted to the back frame <b>10</b> of the harness <b>100</b>. A first end <b>2</b> of the gas-cylinder is supported by a lower portion <b>11</b> of the back frame <b>10</b> and a second end <b>3</b> of the gas-cylinder is supported by an upper portion of the back frame <b>10</b>. The first end <b>2</b> of the gas-cylinder is attached to the reducer valve <b>140</b> that is mounted within a lower portion of the back frame <b>10</b> and the second end <b>3</b> is strapped to the upper portion of the back frame using the retaining strap <b>136</b>.

p-0036<figref idrefs="DRAWINGS">FIG. 3</figref> shows a front view of the back frame <b>10</b> alone. The back frame <b>10</b> comprises a first part <b>20</b> a second part <b>30</b> and a yoke <b>40</b>. The first and second parts <b>20</b>, <b>30</b> 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 <b>12</b> of the back frame <b>10</b> which is coincident with the centre line of the back frame <b>10</b>. The first and second parts <b>20</b>, <b>30</b> are connected together towards the upper portion of the back frame <b>10</b> by the yoke <b>40</b>.

p-0037The first part <b>20</b> comprises a first lower portion <b>22</b> and a first upper portion <b>24</b> that make up the lower portion <b>11</b> of the back frame <b>10</b>. A first side limb <b>26</b> extends longitudinally and connects the first lower portion <b>22</b> to the first upper portion <b>24</b>. The first part <b>20</b> further comprises a first side flange <b>28</b> which comprises two fixing portions <b>27</b>, <b>29</b> to which the left shoulder strap <b>110</b> and the waist strap <b>130</b> can be attached.

p-0038The second part <b>30</b> comprises a second lower portion <b>32</b> and a second upper portion <b>34</b>. A second side limb <b>36</b> extends longitudinally and connects the second lower portion <b>32</b> to the second upper portion <b>34</b>. The second part <b>30</b> further comprises a second side flange <b>38</b> which comprises two fixing portions <b>37</b>, <b>39</b> to which the right shoulder strap <b>120</b> and the waist strap <b>130</b> can be attached.

p-0039The first and second side limbs <b>26</b>, <b>36</b> define a void <b>14</b> in a central region of the back frame <b>10</b>. The void <b>14</b> is delimited by the first and second side limbs <b>26</b>, <b>26</b>, the lower portion <b>11</b> of the back frame <b>10</b> and the yoke <b>40</b> (or upper portion of the back frame <b>10</b>). The void <b>14</b> extends longitudinally along, and transversely across, the majority, or at least a substantial portion, of the back frame <b>10</b>.

p-0040With reference to <figref idrefs="DRAWINGS">FIG. 4</figref>, the yoke <b>40</b> of the back frame <b>10</b> comprises first and second attachment portions <b>42</b>, <b>44</b> for attaching the yoke <b>40</b> to the first and second parts <b>20</b>, <b>30</b> respectively. The first and second attachment portions <b>42</b>, <b>44</b> each comprise a tongue <b>41</b>, <b>43</b> (described in more detail below). The yoke <b>40</b> further includes left and right shoulder strap fixing portions <b>46</b>, <b>48</b> to which the left and right shoulder straps <b>110</b>, <b>120</b> can be attached.

p-0041<figref idrefs="DRAWINGS">FIG. 5</figref> shows a rear view of the back plate <b>10</b> alone. The first side limb <b>26</b> comprises a first guide channel <b>25</b> and the second side limb <b>36</b> comprises a second guide channel <b>35</b>. The channels <b>25</b>, <b>35</b> are arranged to accommodate and retain the high-pressure hose <b>150</b> and the medium pressure hose <b>152</b> respectively. The guide channels <b>25</b>, <b>35</b> 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.

p-0042<figref idrefs="DRAWINGS">FIG. 6</figref> shows the back frame <b>10</b> in a disassembled state. As can be seen, the first part <b>20</b>, second part <b>30</b> and yoke <b>40</b> are completely separable. The first and second parts <b>20</b>, <b>30</b> are attached along a longitudinal axis <b>12</b> of the back frame <b>10</b>. The first part <b>20</b> comprises two protrusions <b>21</b> that, upon assembly, are inserted into two holes in the second part <b>31</b> (not shown). A nut and bolt (not shown) are used to hold a first lower portion <b>22</b> to a second lower portion <b>32</b>. The yoke <b>40</b> can be snap-fitted to the first and second upper portions <b>24</b>, <b>34</b> (described in more detail later). A housing for the reducer valve <b>140</b> is defined between the first and second parts <b>20</b>, <b>30</b> in order to retain the reducer valve <b>140</b> on the back frame <b>10</b>.

p-0043In this embodiment the longitudinal extent along which the first and second parts <b>20</b>, <b>30</b> are attached is a longitudinal axis <b>12</b> 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.

p-0044Referring now to <figref idrefs="DRAWINGS">FIG. 7</figref>, the first lower portion <b>22</b> of the first part <b>20</b> comprises a first recess <b>23</b> and the second lower portion <b>32</b> of the second part <b>30</b> comprises a second recess <b>33</b>. During assembly of the harness <b>100</b> first and second lower portions <b>22</b>, <b>32</b> are assembled around the reducer <b>140</b> such that it is housed within both the first recess <b>23</b> and the second recess <b>33</b>. After the first and second lower portions <b>22</b>, <b>32</b> have been fixed together using a nut and bolt (or other fixing device) the reducer is retained within the lower portion <b>11</b> of the back frame <b>11</b>. The housing defined by the first and second recesses <b>23</b>, <b>33</b> of the first and second parts <b>20</b>, <b>30</b> protect any delicate components of the reducer valve <b>140</b> and also reduce the overall profile of the harness <b>100</b> because a portion of the reducer <b>140</b> is located within the back frame <b>10</b>. The reducer <b>140</b> is also fixed to the back frame <b>10</b> without the need for additional fixing components.

p-0045After the first and second parts <b>20</b>, <b>30</b> have been attached together by the first and second lower portions <b>22</b>, <b>32</b>, the yoke <b>40</b> is attached between the first and second upper portions <b>24</b>, <b>34</b>. As shown in <figref idrefs="DRAWINGS">FIG. 8</figref>, this is done by slotting the tongues <b>41</b>, <b>43</b> of the first and second attachment portions <b>42</b>, <b>44</b> of the yoke, into first and second grooves <b>24</b><i>a, </i><b>34</b><i>a </i>(<figref idrefs="DRAWINGS">FIG. 7</figref>) provided in the first and second upper portions <b>22</b>, <b>32</b> of the first and second parts <b>20</b>, <b>30</b>. This is a snap-fit-type connection that can be made without the need for tools.

p-0046The assembled back frame <b>10</b> having a reducer valve <b>140</b> housed within the lower portion <b>11</b> can be seen in <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0047The reducer valve <b>140</b> comprises a cylinder connection portion <b>142</b> that protrudes from the housing such that a gas-cylinder can be attached thereto.

p-0048With reference to <figref idrefs="DRAWINGS">FIG. 10</figref>, after the back frame <b>10</b> has been assembled, a high-pressure hose <b>150</b> and a medium-pressure hose <b>152</b> are attached to the reducer valve <b>140</b>. The high-pressure hose <b>150</b> is located in the first guide channel <b>25</b> of the first side limb <b>20</b> and the medium-pressure hose <b>152</b> is located in the second guide channel <b>35</b> of the second side limb <b>30</b>. The hoses <b>25</b>, <b>35</b> cross to the front side of the back frame <b>10</b> in the region of the yoke <b>40</b>, cross over, and are positioned on the shoulder straps <b>110</b>, <b>120</b> (<figref idrefs="DRAWINGS">FIG. 1</figref>).

p-0049Referring back to <figref idrefs="DRAWINGS">FIG. 1</figref>, assembly of the harness <b>100</b> can be completed by attaching the left and right shoulder straps <b>110</b>, <b>120</b>, the waist strap <b>130</b> and the cylinder retaining strap <b>136</b>. The harness <b>100</b> is particularly light due to the large void <b>14</b> that occupies a substantial area of the back frame <b>10</b>. As can be seen from <figref idrefs="DRAWINGS">FIG. 2</figref>, the void <b>14</b> is substantially longitudinally and transversely coextensive with the gas cylinder <b>1</b>. The first and second side limbs <b>26</b>, <b>36</b> are spaced either side of the gas-cylinder.

p-0050The harness <b>100</b> is also comfortable for a wearer. When a user wears the harness <b>100</b> on his or her back, the back frame <b>10</b> only contacts the user at a lower region and an upper region. When a user bends over his back/spine bends into the void <b>14</b>. This cannot occur with conventional harnesses <b>100</b>. With conventional harnesses a user's back is forced against a back plate when the user bends over, which can be uncomfortable.

p-0051Further, 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.

p-0052In a further embodiment and as shown in <figref idrefs="DRAWINGS">FIGS. 11 and 12</figref>, the structural support member comprises a back plate <b>10</b> as opposed to a frame. The back plate <b>10</b> comprises first and second parts <b>20</b>, <b>30</b> that are attached along a longitudinal axis <b>11</b> of the back plate <b>10</b> that is the centre line of the back plate <b>10</b>. The first part <b>20</b> comprises an upper left shoulder strap fixing portion <b>46</b> and a lower left shoulder strap fixing portion <b>27</b>. The second part <b>30</b> comprises an upper right shoulder strap fixing portion <b>48</b> and a lower right shoulder strap fixing portion <b>37</b>. A central waist belt fixing portion <b>15</b> is also provided.

p-0053The rear side of the back plate (<figref idrefs="DRAWINGS">FIG. 12</figref>) comprises a housing <b>50</b> for a battery <b>60</b>, a pressure transducer <b>70</b>, and a radio telemetry device <b>80</b> (collectively known as components operatively associated with the breathing apparatus). The components <b>60</b>, <b>70</b>, <b>80</b> are retained within the housing which is defined by the first and second parts <b>20</b>, <b>30</b> of the back plate <b>10</b>. During assembly of the back plate <b>10</b>, the first and second parts <b>20</b>, <b>30</b> are assembled around the components <b>60</b>, <b>70</b>, <b>80</b> so as to retain them within the back plate. This arrangement protects the components <b>60</b>, <b>70</b>, <b>80</b> and allows them to be fixed to the back plate without any additional fixtures. The first and second parts <b>20</b>, <b>30</b> can be fixed together using any known mechanisms such as nuts and bolts, snap-fit, adhesive, for example.

p-0054As 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.