The invention relates to a mounting mechanism, in particular, although not exclusively, to a mounting mechanism for retaining a breathable gas pack, such as a plurality of cylinders of breathable gas located side-by-side, to a back plate of a breathing apparatus harness.

Self-contained breathing apparatus (SCBA) typically comprises a harness for supporting a cylinder of compressed breathable gas on the back of a user, a first stage pressure reduction valve for reducing the pressure of the gas within the cylinder, and a fluid supply line connected to a second stage pressure reduction valve (such as a lung demand valve) for supplying the breathable gas to the user. The harness usually comprises a structural support member, such as a back plate or back frame, left and right shoulder straps, and a waist belt. A cylinder of breathable gas is mounted to the back plate by fluidically and structurally connecting the valve of the cylinder to the first stage pressure reduction valve which is attached to a lower portion of the back plate. The harness is typically provided with a retaining strap or band that passes around an upper portion of the cylinder and which restricts movement of the cylinder. Whilst this arrangement is entirely satisfactory, it may be relatively time consuming to mount a cylinder and a certain amount of dexterity may be required. This may be disadvantageous if it is necessary to mount or replace a cylinder quickly whilst wearing protective clothing. Further, it is known to use breathing apparatus having two or more cylinders of breathable gas located side-by-side. In such circumstances each cylinder must be mounted separately and is provided with a separate fluidic and structural connection and a separate retaining band or strap. Therefore, as the number of cylinders of breathable gas is increased, the time taken to mount or replace the cylinders increases.

It is therefore desirable to provide an improved arrangement for mounting a breathable gas pack. The phrase "breathable gas pack" is intended to cover a single cylinder of breathable gas, a plurality of cylinders of breathable gas, or any other portable unit capable of supplying breathable gas to a user. According to an aspect of the invention there is provided breathing apparatus comprising: a breathable gas pack comprising a plurality of longitudinally extending cylinders of breathable gas transversely arranged side-by-side, the breathable gas pack having a gas outlet port and first and second longitudinally spaced mounting portions; and a harness arranged to be worn by a user, the harness comprising: a gas connector arranged to be fluidically connected to the gas outlet port of the breathable gas pack; a longitudinally extending structural support member arranged to support the breathable gas pack; and a mounting mechanism attached to the structural support member and comprising first and second mounts arranged to cooperate with the first and second mounting portions of the breathable gas pack respectively so as to retain the breathable gas pack to the structural support member; wherein the first and second mounts are longitudinally spaced with respect to the structural support member and longitudinally moveable relative to one another between a loading configuration, in which the breathable gas pack can be loaded onto the mounting mechanism, and a retained configuration in which the breathable gas pack is retained by the first and second mounts on the mounting mechanism.

The first and second mounts may be arranged to cooperate with the first and second mounting portions of the gas pack so as to retain the first and second mounting portions. In the retained configuration the mounting mechanism may restrict both longitudinal and transverse movement of the breathable gas pack with respect to the structural support member. In the retained configuration the first mount may restrict the longitudinal and transverse movement of the first mounting portion of the breathable gas pack with respect to the structural support member and the second mount may restrict the longitudinal and transverse movement of the second mounting portion of the breathable gas pack with respect to the structural support member.

The first mount may comprise at least one pin or aperture which is arranged to cooperate with at least one corresponding aperture or pin provided by the first mounting portion of the breathable gas pack. The second mount may comprise at least one cylinder retainer which is arranged to cooperate with a portion, such as an end, of at least one cylinder of the breathable gas pack. The second mount may comprise a plurality of end caps which are each arranged to receive an end of one of the plurality of cylinders of the breathable gas pack.

The mounting mechanism may further comprise a locking mechanism for locking the mounting mechanism in the retained configuration. The mounting mechanism may further comprise an actuation mechanism for moving the first and second mounts between the loading configuration and the retained configuration. The actuation mechanism may comprise a lever which is arranged to operate the actuation mechanism.

The mounting mechanism may further comprise a tension latch arranged to move the first and second mounts between the loading configuration and the retained

configuration and/or to lock the mounting mechanism in the retained configuration. Either the first or second mount may be fixed with respect to the structural support member.

The structural support member may be longitudinally extending, which in use is substantially vertical. The first mount may be located towards the lower end of the structural support member and the second mount may be located towards the upper end of the structural support member.

The mounting mechanism may be configured such that, during normal mounting of a breathable gas pack to the mounting mechanism, the gas connector cannot be fluidically connected to the gas outlet port of the breathable gas pack until the mounting mechanism is in the retained configuration.

The breathing apparatus may further comprise a reducer valve located towards an upper portion of the harness and fluidically connected to the gas connector with a flexible conduit.

According to another aspect of the invention there is provided a mounting mechanism for a breathable gas pack, comprising: first and second mounts arranged to cooperate with first and second mounting portions of the gas pack respectively; wherein the first and second mounts are longitudinally spaced and moveable relative to one another between a loading configuration, in which the gas pack can be loaded onto the mounting mechanism, and a retained configuration, in which the gas pack is retained by the first and second mounts on the mounting mechanism. The breathable gas pack may be a single cylinder of breathable gas, two or more cylinders of breathable gas located side-by-side, one or more spheres of breathable gas, or another pressurised unit of breathable gas. The first and second mounting portions of the gas pack may comprise brackets, lugs, pins, or may be part of a gas cylinder. For example, one of the mounting portions may be the end of the cylinder, or the cylinder valve.

The first and second mounts may be arranged to cooperate with the first and second mounting portions of the gas pack so as to retain the first and second mounting portions. In the retained configuration, the mounting mechanism may restrict both longitudinal and transverse movement of the gas pack. For example, the mounting mechanism may restrict or prevent upwards, downwards and sideways movement of the gas pack. In the retained configuration, the first mount may restrict the longitudinal and transverse movement of the first mounting portion of the gas pack and the second mount may restrict the longitudinal and transverse movement of the second mounting portion of the gas pack. For example, one of the mounts may restrict or prevent sideways and upwards movement, and the other mount may restrict or prevent sideways and downwards movement. The first mount may comprise at least one pin or aperture which is arranged to cooperate with at least one corresponding aperture or pin provided by the first mounting portion of the gas pack. In one embodiment the first mount may comprise two laterally spaced pins arranged to cooperate with two corresponding apertures provided on the gas pack. Alternatively, the first mount may comprise two apertures and the gas pack may comprise two corresponding pins. Of course, the first mount may comprise a pin and an aperture, and the gas pack may comprise an aperture and a pin.

The second mount may comprise at least one cylinder retainer which is arranged to cooperate with a portion of at least one gas cylinder of the gas pack. In such an arrangement the second mount in the form of a cylinder retainer is arranged to receive a portion of a gas cylinder so as to restrict the movement of the gas pack. The cylinder retainer may be a cylinder end cap arranged to receive and cooperate with the end of a gas cylinder. If the gas pack comprises a plurality of cylinders of breathable gas located side-by-side, the second mount may comprise a corresponding number of cylinder end caps, each arranged to receive the end of a gas cylinder of the gas pack. In one embodiment the second mount is fixed and the first mount is moveable.

Alternatively, both mounts may be moveable, or the first mount may be fixed. The mounting mechanism may further comprise a locking mechanism for locking the mounting mechanism in the retained configuration. This may prevent relative movement between the first and second mounts and therefore may prevent a gas pack from becoming unintentionally detached from the mounting mechanism. The mounting mechanism may further comprise an actuation mechanism for moving the first and second mounts between the loading configuration and the retained configuration. The actuation mechanism may comprise a lever which is arranged to operate the actuation mechanism.

The mounting mechanism may further comprise a tension latch arranged to move the first and second mounts between the loading configuration and the retained

configuration and/or to lock the mounting mechanism in the retained configuration. The tension latch may perform the function of both a locking mechanism and an actuation mechanism. The invention also relates to a harness for breathing apparatus comprising a structural support member, such as a back plate or a back frame, arranged to support a breathable gas pack; a mounting mechanism in accordance with any statement herein attached to the structural support member and arranged to retain a breathable gas pack to the structural support member; and a gas connector arranged to be fluidically connected to a gas port of the breathable gas pack. The first or second mount may be fixed with respect to the structural support member. The structural support member may support the gas pack on the back of a user. The harness may comprise left and right shoulder straps and a waist belt. The structural support member may be longitudinally extending, which in use is substantially vertical. The first mount may be located towards the lower end of the structural support member. The second mount may be located towards the upper end of the structural support member. The mounting mechanism may be configured such that, during normal mounting of a breathable gas pack to the mounting mechanism, the connector cannot be fluidically connected to the gas port of the gas pack until the mounting mechanism is in the retained configuration.

The harness may further comprise a first stage pressure reduction valve located towards an upper portion of the harness and fluidically connected to the gas connector with a flexible conduit.

The invention further relates to breathing apparatus comprising: a harness in accordance with any statement herein; and a breathable gas pack attached to the structural support member; wherein the first and second mounts of the mounting mechanism cooperate with first and second mounting portions of the gas pack respectively so as to retain the breathable gas pack to the structural support member.

The gas pack may comprise at least one gas cylinder. The gas pack may comprise a plurality of gas cylinders arranged side-by-side. The second mount may comprise a plurality of cylinder caps, each arranged to receive and cooperate with an end of a cylinder of the gas pack. The first mount may comprise one or more pins or apertures arranged to cooperate with a corresponding number of apertures or pins provided on the gas pack.

In accordance with another aspect of the invention there is provided a breathable gas pack storage station comprising: a structural support; and a mounting mechanism in accordance with any statement herein attached to the structural support and arranged to retain a breathable gas pack to the structural support.

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

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

Figure 1 schematically shows a perspective view of breathing apparatus;

Figure 2 schematically shows a perspective view of the breathable gas pack of Figure 1 ; Figure 3 schematically shows an end view of the breathable gas pack of Figure 1 ;

Figure 4 schematically shows a perspective view of the harness of Figure 1 in a loading configuration;

Figure 5 schematically shows a perspective view of the harness of Figure 1 in a retained configuration;

Figure 6 schematically shows a side view of the latching mechanism of the harness of Figure 4 in the loading position;

Figure 7 schematically shows a side view of the latching mechanism of Figure 6 in an intermediate position between the loading position and the retained position; Figure 8 schematically shows a side view of the latching mechanism of Figure 6 in the retained position;

Figure 9 schematically shows a side view of the harness of Figure 4 in the loading configuration with a gas pack mounted thereto;

Figure 10 schematically shows a side view of the harness of Figure 5 in the retained configuration with a gas pack mounted and retained thereto;

Figure 1 1 schematically shows a front view of the harness of Figure 4 in the loading configuration with a gas pack mounted thereto; and

Figure 12 schematically shows a front view of the harness of Figure 5 in the retained configuration with a gas pack mounted and retained thereto. Figure 1 shows a self contained breathing apparatus (SCBA) 10 comprising a harness 12 and a breathable gas pack 14 mounted to and retained on the harness 12. The harness 12 comprises a structural support member 16, in the form of a back plate, a mounting mechanism 21 which is arranged to retain the gas pack 14 to the back plate 16, a pair of shoulder straps 18, and a waist belt 20. The harness 12 also comprises various components for the supply of breathable gas from the gas pack 14 to a user. With reference to Figures 2 and 3, the gas pack 14 comprises three longitudinally extending coextensive cylinders of breathable gas 22, 24, 26 located side-by-side in a curved formation, with the central cylinder 24 disposed slightly forwardly of the two side cylinders 22, 26. The curved formation provides a concave rear side, that in use is held against the front face of the back plate 16, and a convex front side. The lower end of each cylinder 22, 24, 26 has a neck terminating at a valved port and the upper end of each cylinder 22, 24, 26 is domed.

The cylinders 22, 24, 26 are held side-by-side in their curved formation by a retaining clamp 28 clamped around the upper portions of the three cylinders 22, 24, 26. The clamp 28 restricts both longitudinal and transverse relative movement between the cylinders 22, 24, 26. The gas pack 14 further comprises a manifold 30 to which the valved port of each cylinder 22, 24, 26 is connected. The manifold 30 provides a structural support for the three cylinders 22, 24, 26 and also provides a common fluid line. The manifold 30 is provided with a common gas port 32 which is located below the central cylinder 24 on the rear side, and a control valve 34 which is located on the front side for controlling the supply of breathable gas through the gas port 32. The gas port 32 projects rearwardly and obliquely away from the manifold 30, and the control valve 34 projects forwardly and obliquely away from the manifold 30. A manifold housing 36 is provided that protectively houses the manifold 30.

The gas pack 14 further comprises two mounting brackets 38, 40 attached to the manifold 30 and which extend upwardly and which lie in a vertical plane. The mounting brackets 38, 40 are located either side of the central cylinder 24. Each bracket 38, 40 comprises a longitudinally extending keyhole slot 42 having an upper narrow slot 44 and a lower enlarged aperture 46. As will be described in detail below, the mounting brackets 38, 40 are used to mount the gas pack 14 to the harness 12.

Referring now to Figures 4 and 5, the harness 12 comprises a longitudinally extending rigid back plate 16, left and right shoulder straps 18 attached to the back plate at their upper and lower ends, and a waist belt 20 attached to left and right sides of the back plate 16. The back plate 16 provides structural rigidity to the harness 12 which is arranged to be worn on the back of a wearer. The harness 12 further comprises a mounting mechanism 21 comprising three cylinder end caps 66, 68, 70 attached to an upper part of the back plate 16, a longitudinally extending concave mounting plate 48 attached to the front side of back plate 16, and a horizontal mounting bar 64 having two mounting pins 78 and which is longitudinally moveable with respect to the back plate 16. Each of the cylinder end caps 66, 68, 70 comprises a cylindrical side wall defining an open lower end. The end caps 66, 68, 70 are all of the same diameter which is slightly larger than the outer diameter of the cylinders 22, 24, 26. The end caps 66, 68, 70 are attached to a common upper plate 71 which covers the upper end of the caps 66, 68, 70 and maintains them in a curved profile which corresponds to the curved profile of the gas pack 14. The upper plate 71 is attached to an upper portion of the front face of the back plate 16 so that the open lower ends of the end caps 66, 68, 70 face downwards. This allows the upper domed end of each cylinder 22, 24, 26 of the gas pack 14 to be inserted into and retained within a respective end cap 66, 68, 70. The mounting plate 48 is attached to the front face of the back plate 16 and extends from the lower end of the back plate 16 towards the upper end of the back plate 16 along the longitudinal centreline of the back plate 16. The mounting plate 48 has a concave front face having a profile corresponding to that of the central cylinder 24 of the gas pack 14. The concave front face is therefore arranged to receive the central cylinder 24 of the gas pack 14 with the other two cylinders 22, 26 disposed either side.

The mounting bar 64 is horizontally extending and is disposed below the lower end of the mounting plate 48 and has substantially the same lateral extent. Two forwardly projecting cylindrical spacers 76 are provided at either side of the mounting bar 64 and each supports a forwardly projecting mounting pin 78. The spacers 76 and mounting pins 78 are laterally spaced apart by the same distance as the mounting brackets 38, 40 of the gas pack 14 so as to cooperate therewith. Each mounting pin 78 comprises a neck portion 80 and an enlarged head 82 having a frustoconical tip. The head 82 has a diameter that is slightly less than the diameter of the enlarged aperture 46 of the keyhole slot 42 but greater than the width of the narrow slot 44. The neck 80 has a diameter that is slightly less than the width of the narrow slot 44 of the keyhole slot 42. Therefore, the head 82 of the pin 78 can be inserted into the enlarged aperture 46 of the keyhole slot 42 and moved vertically upwards such that the neck 80 is located within the narrow slot 44. This prevents the pin 78 from being withdrawn from the keyhole slot 42 without moving it vertically downwards. The mounting bar 64 is also provided with a downwardly projecting safety tab 84; the function of which will be described in detail below.

The mounting bar 64 is coupled to the mounting plate 48 by two retractable struts 86 such that it is longitudinally moveable with respect to the mounting plate 48 and the back plate 16. The struts 86 are parallel and longitudinally extending and are disposed at either side of the mounting bar 64. The struts 86 are telescopically received within corresponding housings (not shown) that are attached to the mounting plate 48. The struts 86 therefore act to guide the longitudinal movement of the mounting bar 64. The mounting bar 64 can move between an extended loading position (Figure 4) in which it is longitudinally spaced away from the mounting plate 48 and back plate 16, and a retracted retained position (Figure 5) in which it is adjacent to the mounting plate 48 and back plate 16. The function of these positions will be described in detail below. The mounting mechanism 21 further comprises a biasing means 88 in the form of a spring that is attached between the mounting plate 48 and the mounting bar 64. The biasing means 88 biases the mounting bar 64 away from the mounting plate 48 and back plate 16 towards the loading position (Figure 4). The mounting mechanism 21 also comprises a locking and actuation mechanism in the form of an over-centre latch 90. The latch 90 is capable of moving the mounting bar 64 between the loading and retaining positions, and can also be used to lock the mounting bar 64 in the retained configuration. With reference to Figures 6-8, the over-centre latch 90 comprises a latch member 94 having an upper end pivotably coupled to the lower end of the mounting plate 48 at an upper pivot 96, and a lever 98 having a lower end pivotably coupled to the mounting bar 64 at a lower pivot 100. The lower pivot 100 is disposed a short distance rearwardly of the upper pivot 96. This distance does not change as the mounting bar 64 longitudinally moves as the struts 86 prevent lateral movement of the mounting bar 64. The lever 98 is pivotably coupled to the latch member 94 part way along its length at a central pivot 102. The lever 98 comprises a handle 104 disposed on one side of the central pivot 102 and a bar 102 disposed between the central pivot 102 and the lower pivot. Figure 6 shows the latch 90 in an open configuration with the mounting bar 64 spaced away from the mounting plate 48 in the loading position. In the open configuration of the latch 90, the handle portion 104 extends upwardly from the central pivot 102.

Referring now to Figure 7, anti-clockwise rotation of the handle portion 104 of the lever 98 about the central pivot 102 causes the central pivot 102 to move rearwardly and the mounting bar 64 to move longitudinally upwardly towards the mounting plate 48. As shown in Figure 8, continued rotation of the handle portion 104 causes the central pivot 102 to move below the lower pivot 100 and past the common centreline 106 of the upper and lower pivots 96, 100 to a locked configuration. In the locked configuration of the latch 90 the mounting bar 64 is in the retained position in which it is adjacent to the mounting plate 48.

With the mounting bar 64 in the retained position and the latch 90 in the locked configuration, forces acting between the mounting plate 48 and mounting bar 64 (such as the spring force exerted by the biasing means 88) act through the central pivot 102. This keeps the lever 98 in the locked position, and therefore the mounting bar 48 in the retained position, since the central pivot 102 is below the common centreline 106 of the upper and lower pivots 96, 100. In order to move the mounting bar 64 to the loading position, a force must be applied to the handle portion 104 of the lever so as to move the central pivot 102 past the centreline 106. This mechanism is known as an over- centre tension latch.

In addition to the components described above, the harness 12 also comprises a first stage pressure reduction valve 54 attached to an upper part of the back plate 16 and a gas connector 50 for making a fluidic connection with the gas port 32 of the gas pack 14. The gas connector 50 is attached to an inlet of the reducer valve 54 with a flexible conduit 52 and hangs below the bottom of the back plate 16. The flexible conduit 52 is located within a guide channel in the rear of the back plate 16. A second stage pressure reduction valve (such as a lung demand valve (LDV)) 56 is connected to an intermediate pressure outlet of the first stage pressure reduction valve 54 and a pressure gauge 60 is connected to a high pressure outlet of the first stage pressure reduction valve reducer valve 54. In use, the LDV is attached to a face mask or hood (not shown) that is worn by the user and breathable gas is supplied from the gas pack 14 to the user through the LDV 56. With reference to Figures 9-12, in order to attach the gas pack 14 to the harness 12, the harness 12 is laid horizontally and the mounting mechanism 21 is moved to the loading position (Figures 9 and 1 1) in which mounting bar 64 is longitudinally spaced away from the mounting plate 48 and back plate 16. The gas pack 14 is then aligned with the harness 12 and the enlarged heads 82 of the two mounting pins 78 are inserted into the enlarged apertures 46 of the respective mounting brackets 38, 40. In such a position the central cylinder 24 rests in the concave front face of the mounting plate 48. Further, the safety tab 84 sits over the gas port 32 and prevents the gas connector 50 from being fluidically coupled to the gas port 32. The gas pack 14 is then longitudinally moved towards the cylinder end caps 66, 68, 70 which are located at the upper end of the harness 12. This results in relative movement between the gas pack 14 and the back plate 16 but the mounting bar 64 moves with the gas pack 14 and therefore the safety tab 84 remains over the gas port 32 preventing a connection from being made. As the upper ends of the cylinders 22, 24, 26 of the gas pack 14 near the cylinder end caps 66, 68, 70, the handle 104 of the lever 98 is rotated so as to draw the mounting bar 64 towards the mounting plate 48 and back plate 16. This forces the ends of the cylinders 22, 24, 26 into the end caps 66, 68, 70 (Figure 10) and also moves the mounting bar 64 relative to the gas pack 14 such that the necks 80 of the mounting pins 78 move into the narrow slots 44 of the respective keyhole slots 42 (Figure 12). The lever 98 is then fully moved into the locked position (Figure 8) in which the mounting mechanism 21 is in the retained configuration. The relative movement between the mounting bar 64 and gas pack 14 moves the safety tab 84 away from the gas port 32 and therefore the gas connector 50 can be fluidically connected to the gas port 32. The safety tab 84 therefore prevents a gas connection being made before the gas pack 14 has been fully locked to the harness 12.

In the retained configuration the upper ends of the cylinders 22, 24, 26 are retained within the end caps 66, 68, 70 which prevent both upwards and lateral movement of the gas pack. In the retained configuration the mounting pins 78 are engaged with the keyhole slots 42 of the mounting brackets 38, 40 which prevents downwards and lateral movement of the gas pack. Accordingly, in the retained configuration the gas pack 14 is securely mounted and retained to the back plate 16 of the harness 12 by the mounting mechanism 21. Further, the mounting operation can be achieved quickly and with ease and multiple cylinders can be mounted in a single operation. In order to remove the gas pack 14 from the harness 12 the reverse operation is performed. Specifically, the lever 98 is rotated out of the locked configuration and the biasing means 88 automatically moves the mounting bar 64 away from the mounting plate 48 and back plate 16 to the unloading configuration. This movement of the mounting bar 64 causes the ends of the cylinders 22, 24, 26 to be withdrawn from the end caps 66, 68, 70. The gas pack 14 can then be moved with respect to the mounting bar 64 so as to move the mounting pins 78 within the keyhole slots 42 such that the pins 78 are positioned within the enlarged apertures 46. This allows the gas pack 14 to be fully removed from the harness 12. Again, this procedure can be achieved quickly and with ease.

Although not shown in the figures, the mounting mechanism 21 may also be used in a gas pack mounting station for storing gas packs 14. In such an arrangement the mounting mechanism 21 is mounted to a wall or panel so that the end caps 66, 68, 70 are fixed to the wall or panel and the mounting bar 64 is able to move longitudinally. Thus, a gas pack 14 can be located onto the mounting pins 78 and the latch 90 can be actuated to move the mounting mechanism 21 to the retaining configuration in which the gas pack 14 is retained to the wall or panel. In the embodiment described above the mounting brackets 38, 40 of the gas pack 14 provide the function of a first mounting portion and the ends of the cylinders 66, 68, 70 provide the function of a second mounting portion. The mounting pins 78 of the mounting mechanism 21 provide the function of a first mount and the cylinder end caps 66, 68, 70 provide the function of a second mount.

It should be appreciated that other mounts (provided by the mounting mechanism) and mounting portions (on the gas pack) may be provided. For example, if the gas pack comprises a single cylinder of breathable gas, the first mounting portion may be the cylinder valve and the second mounting portion may be the upper end of the cylinder. The mounting mechanism may comprise a first mount in the form of a first stage pressure reduction valve, and a second mount in the form of a cylinder end cap. In use, the cylinder valve may be fluidically and structurally coupled to the first stage pressure reduction valve and relative movement between the first stage pressure reduction valve and end cap may cause the end of the cylinder to move into the end cap, thereby securing the cylinder. Although it has been described that a latch provides the features of an actuation mechanism and a locking mechanism, it should be appreciated that in other embodiments the relative movement between the first and second mounts may be achieved without an actuation mechanism, and a locking catch may be provided to lock them in place.