An inline motorised fan module and a powered air-purifying respirator system

Abstract

The present invention discloses an inline motorised fan module for a helmet. The inline motorised fan module comprises a fan, a connector configured to couple the fan inline between a primary air hose and an inlet of the helmet, at or integrated with a helmet outlet, or within a helmet cavity, and an electrical interface configured to draw power from a power source of the PAPR unit, a helmet power source or auxiliary port, or an integrated power source of the module. The fan is configured to increase the volume of airflow delivered into the helmet to improve respiratory comfort for a user. The invention also provides a powered air-purifying respirator system and methods of supplying airflow using the inline motorised fan module.

Description

[0001] AN INLINE MOTORISED FAN MODULE AND A POWERED AIR-PURIFYING RESPIRATOR SYSTEM

[0002] Field of the Invention

[0003] [1] The present invention relates to an inline motorised fan module and a powered air-purifying respirator system, and in particular to an inline motorised fan module for a helmet and a powered air-purifying respirator system comprising the inline motorised fan module.

[0004] [2] The invention has been developed primarily for use in welding applications and will be described hereinafter with reference to this application. It will, however, be appreciated that the invention is not limited to this particular field of use.

[0005] Background of the Invention

[0006] [3] Respiratory helmet systems are devices designed for enabling a user to draw in air from the environment while simultaneously protecting the user from inhaling unwanted, hazardous, or contaminating particles. Such systems have applications in fields including medical disease control, firefighting and rescue, chemical handling, mining, construction, and welding. Welders, in particular, are frequently exposed to hazardous fumes, fine particulates, and airborne pollutants that can pose serious health risks when inhaled. Prolonged exposure to such conditions can lead to respiratory illnesses, reduced lung capacity, and other long-term health effects. In addition to respiratory hazards, welding environments often involve elevated temperatures, sparks, and physical exertion, all of which can compound discomfort and fatigue for the user. Ensuring a consistent flow of clean, breathable air is therefore essential for both safety and comfort in such demanding work conditions.

[0007] [4] Various powered air-purifying respirator (PAPR) systems and respiratory helmet designs have been developed to address these concerns. They typically have a fan and filtration unit that draws in ambient air, removes harmful particulates, and delivers the filtered air through a hose to the user’s helmet or face covering. In welding applications, some solutions incorporate helmet-mounted airflow channels to distribute air more evenly, while others integrate higher-capacity filters to extend operational time before maintenance is required. Some systems are also designed with adjustable airflow rates or automated sensors to respond to changing environmental conditions.

[0008] [5] While these existing solutions provide varying degrees of respiratory protection and comfort, they are not without limitations. In many cases, as filters accumulate dust and particulates, airflow resistance increases, leading to reduced air delivery and potential system performance alerts. To compensate, some systems attempt to increase fan speed, which can rapidly drain battery power and shorten operational duration. Additionally, airflow distribution inside the helmet is not always optimal, resulting in uneven cooling and discomfort during prolonged use. The added weight or bulk of certain systems can also negatively affect user mobility and ergonomics, particularly in confined workspaces.

[0009] [6] Conventional PAPR systems are limited to single-user configurations, while multi-user airline systems require tethering to fixed compressors, and refuge packs are static shelters. There is no system providing multi-user capability combined with battery portability and integration with PAPRs, enabling mobile inspection and hazardous environment work

[0010] [7] Therefore, there is a need for a solution that supports the health, safety, and endurance of users working in demanding welding and similar industrial environments, without compromising on portability, ergonomics, or operational duration.

[0011] [8] Any discussion of the background art throughout the specification should in no way be considered as an admission that such background art is prior art nor that such background art is widely known or forms part of the common general knowledge in the field in Australia or worldwide.

[0012] Summary of the Invention

[0013] [9] According to an aspect of the present invention, an inline motorised fan module for a helmet is provided. The inline motorised fan module comprising a fan, a connector configured to couple the fan inline between a primary air hose and an inlet of the helmet, at or integrated with a helmet air outlet, or within a helmet cavity and an electrical interface configured to draw power from a power source. Further, the fan is configured to increase the volume of airflow delivered into the helmet to improve respiratory comfort for a user.

[0010] Advantageously in this embodiment, the inline motorised fan module allows the fan to directly supplement the airflow supplied to the helmet without requiring modification to the primary air supply system. By positioning the fan inline between the primary air hose and the helmet inlet, airflow losses due to hose length, bends, or filter resistance are reduced, ensuring consistent delivery of air volume to the user. The electrical interface, which draws power from the helmet’s primary power source, eliminates the need for a separate power unit, reducing weight and complexity. Together, these features enhance respiratory comfort, maintain adequate ventilation during high-demand conditions, and improve user endurance in contaminated or high- temperature environments.

[0014]

[0011] In an embodiment, the power source is a power source of the PAPR unit, a helmet power source or auxiliary port, or an integrated power source of the module.

[0015]

[0012] In one embodiment, the electrical interface is operable with a low voltage auxiliary output of the primary power source of the helmet.

[0016]

[0013] In one embodiment, the fan is configured to maintain airflow in the range of, but not limited to, 200 to 400 litres per minute, in particular 270 to 305 litres per minute during operation.

[0017]

[0014] In one embodiment, the fan is configured to operate in a startup burst mode providing airflow exceeding 305 litres per minute for a predetermined duration before reaching a predetermined airflow rate.

[0018]

[0015] In one embodiment, the inline motorised fan module further comprises a user- operable control switch configured to adjust fan speed to maintain a desired airflow.

[0019]

[0016] In one embodiment, the inline motorised fan module further comprises a coupling module configured for installation onto an existing powered air-purifying respirator system without modification to the primary air hose or helmet.

[0020]

[0017] In one embodiment, the fan is configured to distribute airflow more evenly within the helmet cavity to enhance user comfort.

[0021]

[0018] In one embodiment, the fan is an axial fan.

[0022]

[0019] In one embodiment, the primary power source is a battery powered source.

[0020] In one embodiment, the connector is configured to couple the fan inline within an air hose, conduit, or duct used to convey breathable air to a respirator headpiece or confined workspace.

[0023]

[0021] According to another aspect of the present invention, a powered air-purifying respirator system is provided. The powered air-purifying respirator system comprising a primary fan and filter unit configured to deliver filtered air through an air hose, a head cover adapted to receive the airflow, an inline fan module coupled between the air hose and the head cover. Further, the inline fan module is configured to supplement the primary airflow when the filter unit experiences increased resistance, thereby maintaining or increasing airflow into the head cover to reduce system performance alerts and improve respiratory comfort for a user.

[0024]

[0022] Advantageously in this embodiment, the use of an inline fan module to supplement the primary airflow ensures that performance is maintained even as filter resistance rises due to particulate loading. This arrangement avoids the common problem in existing systems where reduced airflow triggers safety alarms or forces the user to stop work to replace or clean the filter. By boosting the airflow downstream of the primary filter unit, the system can deliver consistent ventilation without increasing the primary fan’s load, which extends battery life and reduces mechanical strain on the primary components. The result is improved safety, continuous operation in high- dust environments, and greater comfort for the user over extended work periods.

[0025]

[0023] In one embodiment, the fan generates a turbulent airflow pattern that enhances heat dissipation and increases sweat evaporation inside the helmet.

[0026]

[0024] In one embodiment, the combined airflow from the primary fan and inline fan reduces user breathing effort and enhances endurance during extended use.

[0027]

[0025] In one embodiment, the powered air-purifying respirator system further comprises a control switch configured to maintain operational airflow under environmental conditions including high ambient temperature, elevated physical exertion, welding fume exposure, or airborne particulates.

[0028]

[0026] In one embodiment, the inline fan includes a controller configured to adjust fan speed dynamically based on downstream airflow pressure or flow rate.

[0029]

[0027] In one embodiment, the inline fan is an inline axial fan.

[0028] In one embodiment, the powered air-purifying respirator system further comprises a battery powered source.

[0030]

[0029] In one embodiment, at least one inline fan module is positioned within a hose, conduit, or duct of an air supply line upstream of the head cover, to compensate for airflow losses along the supply path.

[0031]

[0030] In one embodiment, the primary fan and filter unit is replaced by or supplemented with an external breathable air supply line, including a long-line rescue or emergency air supply, the inline fan module being configured to compensate for line resistance and maintain stable positive pressure at the head cover. Preferably, the primary fan and filter unit is battery-powered to enable portable, multi-user operation without fixed compressors or airline tethering.

[0032]

[0031] In one embodiment, an exhaust conduit or outlet is provided, which is configured to assist in removing exhaled carbon dioxide from the head cover in combination with the supplemental fan airflow.

[0033]

[0032] According to a further aspect of the present invention, a powered air-purifying respirator system is provided. The powered air-purifying respirator system comprising a battery-powered fan and filter unit configured to deliver filtered air at a total flow rate of up to or exceeding 400 litres per minute, a dual outlet manifold configured to divide the airflow into at least two separate air delivery hoses and at least two head covers, each adapted to receive airflow from one of the air delivery hoses. Further, the battery- powered fan and filter unit configured to simultaneously supply at least 200 litres per minute to each of the two head covers to support two users concurrently.

[0034]

[0033] Advantageously in this embodiment, the dual outlet manifold combined with a high-capacity fan and filter unit enables a single powered air-purifying respirator system to support two users at once without compromising airflow requirements. This configuration significantly reduces equipment costs, maintenance effort, and storage needs compared to using two separate systems. The ability to maintain at least 200 litres per minute to each head cover ensures compliance with safety airflow standards, even in high-demand or high-resistance scenarios. Additionally, the arrangement promotes operational efficiency in environments where multiple operators are working in close proximity, such as welding bays, confined spaces, or assembly lines, by centralising air supply equipment and minimising downtime for battery or filter changes.

[0035]

[0034] In one embodiment, the battery-powered fan unit includes a controller configured to regulate and balance airflow between the two hoses based on downstream pressure.

[0036]

[0035] In one embodiment, the fan and filter unit include a replaceable high-capacity filter capable of supporting continuous operation at 400 litres per minute for a predetermined duration.

[0037]

[0036] In one embodiment, each of the two head covers include an inline fan module configured to supplement the delivered airflow to maintain comfort under increased respiratory demand or filter resistance.

[0038]

[0037] In one embodiment, the dual outlet manifold includes flow restrictors or valves configured to maintain independent airflow rates to each user.

[0039]

[0038] In one embodiment, the dual outlet manifold is replaced by or extended to a multi-outlet manifold configured to supply airflow to more than two head covers, each head cover including an inline fan module.

[0040]

[0039] According to one aspect of the invention, there is provided a method of supplying airflow in a powered air-purifying respirator (PAPR) system. The method comprises a primary fan and filter unit that delivers filtered air through an air hose to a head cover or helmet worn by a user. The method also comprises a supplemental fan that is positioned inline between the air hose and a helmet air inlet, or at or integrated with a helmet outlet connector, or within a helmet cavity. The method further comprises operating the supplemental fan to generate airflow into the head cover in addition to airflow from the primary fan and filter unit. The method also comprises generating a turbulent airflow pattern within the helmet cavity to enhance cooling, reduce stagnant zones, and improve respiratory comfort for the user. In addition, the turbulent airflow continues when resistance at the filter unit increases.

[0041]

[0040] Advantageously, this embodiment ensures that airflow is supplemented directly at the point of greatest resistance, such as the helmet interface or within the helmet cavity itself. Maintaining a controlled airflow at levels suitable for respiratory protection, for example in the range of about 200 to 400 L / min, and optionally in a preferred range of about 270 to 305 L / min with the option of a temporary burst above 305 L / min, ensures compliance with current safety airflow requirements while providing immediate relief under high-demand conditions. The capability to draw power from multiple sources, including the PAPR unit, existing helmet auxiliary ports, or integrated batteries, eliminates the need for dedicated power modules and reduces overall system weight and complexity. In addition, generating turbulent airflow within the helmet cavity enhances heat dissipation and sweat evaporation, thereby reducing operator fatigue and extending endurance in hot, contaminated, or high-exertion environments.

[0042]

[0041] In one embodiment, the method further comprises maintaining airflow at a level suitable for respiratory protection.

[0043]

[0042] In one embodiment, the airflow is maintained in the range of about 200 to 400 litres per minute.

[0044]

[0043] In one embodiment, the airflow is maintained in the range of about 270 to 305 litres per minute.

[0045]

[0044] In one embodiment, the airflow is maintained in a burst mode that exceeds 305 litres per minute for a predetermined duration.

[0046]

[0045] In one embodiment, the method further comprises supplying electrical power to the supplemental fan from at least one of a power source of the PAPR unit, a helmet power source or auxiliary / task-light port, or an integrated battery of the supplemental fan.

[0047]

[0046] In one embodiment, the supplemental fan is an axial fan.

[0048]

[0047] In one embodiment, the method further comprises controlling the supplemental fan by a user-operable switch to set airflow output.

[0049]

[0048] In one embodiment, the method is carried out in a dual-outlet PAPR system that is configured to supply filtered air through two hoses to two helmets, each helmet including a supplemental fan according to the method.

[0050]

[0049] In one embodiment, the method further comprising a step of positioning the supplemental fan inline within a hose, conduit, or duct of an air supply path remote from the helmet, to locally boost airflow and compensate for pressure losses along the path.

[0050] In one embodiment, the airflow is supplied from a centralised filtration and fan unit to a plurality of helmets.

[0051]

[0051] In one embodiment, the airflow is supplied from an external breathable air supply line located remote from the user, the supplemental fan being configured to compensate for resistance along the supply line.

[0052]

[0052] According to another aspect of the present invention, the inline motorised fan module may be applied in a centralised airflow system wherein a single high-capacity filtration and fan unit supplies filtered air through a multi-outlet manifold to multiple users. Each air delivery line is coupled to an inline fan module positioned at or near the user’s helmet inlet, thereby ensuring that airflow to each helmet remains above minimum required levels irrespective of hose length, user count, or distribution imbalance. Advantageously, this configuration supports applications including underground rescue, refuge chambers, tunnelling, or cleanroom environments, where several users may be connected to a common supply source. This arrangement enables scalable respiratory protection solutions across diverse applications including mining, tunnelling, emergency refuge chambers, high-dust manufacturing, smelting, medical cleanrooms, and disaster response operations.

[0053]

[0053] In another embodiment, each inline motorised fan module is configured to supplement and stabilise airflow at the helmet inlet irrespective of hose length, user count, or downstream resistance. Advantageously, this ensures that each user connected to a centralised or multi-outlet powered air-purifying respirator system receives compliant and consistent airflow, even when distribution imbalances occur.

[0054]

[0054] This invention may also be said broadly to comprise in the parts, elements, and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements, or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0055]

[0055] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

[0056]

[0056] Other aspects of the invention are also disclosed.

[0057] Brief Description of the Drawings

[0058]

[0057] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0059]

[0058] Figure 1 shows a front perspective view of an embodiment of an inline motorised fan module of the present invention;

[0060]

[0059] Figure 2 shows a rear perspective view of the inline motorised fan module of Fig. 1 ;

[0061]

[0060] Figure 3 shows a front view of the inline motorised fan module of Fig. 1 ;

[0062]

[0061] Figure 4 shows a right side view of the inline motorised fan module of Fig. 1 ;

[0063]

[0062] Figure 5 shows a cross sectional left side view of the inline motorised fan module of Fig. 1 ;

[0064]

[0063] Figure 6 shows a top view of the inline motorised fan module of Fig. 1 ;

[0065]

[0064] Figure 7 shows a bottom view of an embodiment of the inline motorised fan module showing the inline fan and a portion of the electrical interface housing;

[0066]

[0065] Figure 8 shows the inline motorised fan module replacing a connector of a typical prior art PAPR system; and

[0067]

[0066] Figure 9 shows a prior art PAPR system.

[0068] Description of Embodiments

[0069]

[0067] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[0070]

[0068] An inline motorised fan module for a helmet according to an aspect of the invention is indicated by the numeral 1000.

[0071]

[0069] In the embodiment as shown in Fig. 1 , the inline motorised fan module comprises a housing 1001 , a first end 1002 extending outwardly from a first side of the housing 1001 , and a second end 1003 extending outwardly from a second side of the housing 1001. As shown in Fig. 1 , the first end 1002 extend outwardly and opposite the second end 1003, thereby forming an inline arrangement such that the housing 1001 is located intermediate the first end 1002 and the second end 1003. In use, the first end 1002 is configured to be connected to an inlet of a helmet and the second end 1003 is configured to be connected to an end of a primary air hose such that the inline motorised fan module is positioned inline between the helmet and the primary air hose.

[0072]

[0070] As shown in Fig. 7 the inline motorised fan module includes a inline fan 1004. The inline fan 1004 is rotatably mounted within the housing 1001 , the fan being configured, when in use, to rotate about an axis -A-, as shown in Figs. 1 , 3 and 4. The inline fan 1004 is adapted to blow air towards the first end 1002 such that the blown air will move towards the helmet inlet.

[0073]

[0071] In an embodiment as shown in Fig. 8, the inline motorised fan module 1000 further comprises an electrical interface 1006. The electrical interface 1006 comprises an inlet end and an outlet end. The outlet end is configured for electrically coupling the electrical interface 1006 to the inline fan 1004, and the inlet end is configured for electrically coupling the electrical interface 1006 to a primary power source of the helmet. In use, the electrical interface 1006 is adapted to draw power from a primary power source to the inline fan 1004. In another embodiment, the inlet end of the electrical interface 1006 is configured for electrically coupling the electrical interface 1006 to a power source (“secondary power source”) of an external powered-air purifying respirator, such that in use, the electrical interface 1006 is adapted to draw power from the secondary power source to the inline fan 1004. The inline motorised fan module 1000 is provided with an electrical interface housing 1009 adapted to house the electrical interface 1006, or at least a portion thereof.

[0074]

[0072] In an embodiment, the electrical interface is operable with a low voltage auxiliary output of the primary power source or the secondary power source. In an embodiment, the electrical interface 1006 is a task light cable.

[0075]

[0073] In another embodiment, the inline motorised fan module comprises a built-in power source 1005. The inlet end of the electrical interface 1006 may be electrically coupled to the built-in power source 1005 such that in use, the inline fan 1004 draws power from the secondary built-in power source 1005. The secondary power source 1005 may be housed within the power source compartment 1007 affixed to a portion of the housing 1001.

[0076]

[0074] As shown in Figs. 1-2, 4-5, the inline motorised fan module 1000 includes a user interface 1010. The user interface 1010 is configured to provide fan controls to a user to control the inline fan 1004. In an embodiment, the user interface 1010 can be interacted with to control a power and / or a volume airflow output of the inline fan 1004. In an embodiment, the user interface 1010 is a control switch.

[0077]

[0075] In another embodiment not shown, the inline motorised fan module 1000 comprises a controller configured for adjusting the speed of the inline fan 1004 dynamically based on downstream airflow pressure or flowrate.

[0078]

[0076] In an embodiment, the inline fan 1004 is adapted to increase the volume of airflow delivered into the helmet to improve respiratory comfort for a user. In an embodiment, the fan is configured to maintain airflow in the range of 200 litres per minute (“LPM”) to 400 LPM during operation. In a preferred embodiment, the fan is configured to maintain airflow in the range of approximately 270 to 305 LPM during operation. In an embodiment, the inline fan 1004 is an axial fan.

[0079]

[0077] The inline fan 1004 is further adapted to operate in a startup burst mode. When operating in a startup burst mode, the fan is adapted to further improve airflow exceeding 305 LPM and maintaining such airflow for a predetermined duration before reaching a predetermined airflow rate.

[0080]

[0078] The inline motorised fan module 1000 further comprises a coupling module configured for installation onto an existing powered air-purifying respirator system without modification to the primary air hose or helmet.

[0081]

[0079] Fig. 9 shows a typical prior art Powered air-purifying respirator system 2000. The prior art PAPR system 2000 typically comprises an originating fan 2001 , a filter unit 2002, an air hose 2003, a helmet connector 2004, and a helmet 2005. The powered air-purifying system is powered by a primary power source 2006. The originating fan 2001 and the filter unit 2002 are contained within a housing 2007, the filter unit being coupled to the originating fan 2001. The air hose 2003 comprises a housing end 2031 and a connector end 2032, the housing end 2031 being configured to connect to an end of the housing inline with the filter unit 2002, and the connector end 2032 being configured to connect to a helmet connector inlet of the helmet connector 2004. helmet connector 2004 further comprises a helmet connector outlet adapted to be connected to a helmet inlet 2041 of the helmet 2005. In use, the originating fan 2001 is adapted to draw in air from the environment and blow the air through the filter unit 2002. The filter unit 2002 is then adapted to filter dust, dirt, sediments or other particulate from the incoming air. The filtered air then travels through the air hose 2003, through the helmet connector 2004, and through helmet inlet 2041 . Finally, the filtered air then travels to the helmet to provide air to the user.

[0082]

[0080] An aspect of the present invention provides a powered air-purifying respirator system (not shown), herein referred to as “PAPR”, comprising similar elements to the prior art powered air-purifying respirator system as described and shown in Fig. 9, with the helmet connector 2004 having been replaced with the inline motorised fan module 1000 as described in the foregoing.

[0083]

[0081] In the configuration of the present invention, the first end 1002 of the inline motorised fan 1004 is connected to the helmet inlet and the second end 1003 is connected to connector end 2032. The electrical interface 1006 is then extended such that the inlet end of the electrical interface 1006 is connected to the primary power source.

[0084]

[0082] In use, the originating fan of the PAPR is adapted to draw in air from the environment and blow the air through the filter unit. The filter unit is then adapted to filter dust, dirt, sediments or other particulate from the incoming air. The filtered air then travels through the air hose and towards the inline motorised fan module via the second end 1003. Ultimately, the filtered air then travels to the helmet via the helmet inlet that is connected to the first end 1002 of the inline motorised fan module 1000. As time passes by and the originating fan draws in more air towards the system, the filter becomes saturated with dust, dirt, and other particles which increases the resistance against incoming airflow to the system. The inline fan 1004 can then be activated since it is electrically coupled to the primary power source via the electrical interface 1006. When the inline fan 1004 is activated, the inline fan 1004 is configured to supplement the airflow by the originating fan of the PAPR, thereby maintaining or increasing airflow into the helmet, ultimately reducing system performance alerts and improving respiratory comfort to the user.. The combined airflow from the primary fan and the inline fan 1004 reduces user breathing effort and enhances endurance during extended use. In an embodiment, the inline fan 1004 is adapted to increase the volume of airflow delivered into the helmet and maintain that airflow in the range of 200 litres per minute (“LPM”) to 400 LPM during operation. In a preferred embodiment, the inline fan 1004 is configured to maintain airflow in the range of approximately 270 to 305 LPM during operation. The inline fan can be operated in a startup burst mode where it can further improve airflow exceeding 305 LPM.

[0085]

[0083] In an embodiment, the user, through the user interface 1010, may set a power or desired volume airflow output of the inline fan 1004. In another embodiment, the user via the user interface may set a predetermined duration for the inline fan to maintain an airflow. The user interface 1010 may likewise be interacted with to such that an operational airflow is maintained under environmental conditions including high ambient temperature, elevated physical exertion, welding fume exposure or airborne particles.

[0086]

[0084] In another embodiment, the speed of the inline fan 1004 is adjusted dynamically by the controller based on downstream airflow pressure or flow rate.

[0087]

[0085] The inline fan 1004 may be configured via the controller or the user interface 1010 to generate a turbulent airflow pattern that enhances dissipation and increases sweat evaporation inside the helmet.

[0088]

[0086] In another embodiment, the inline fan 1004 is connected to the built-in power source 1005 to save the power level of the primary power source. In this configuration, the inline fan 1004 is powered by the built-in power source instead of the primary power source.

[0089]

[0087] Another aspect of the present invention provides a PAPR system having the inline motorised fan module 1004 as described in the foregoing, the PAPR system further comprising a dual outlet manifold (not shown), a first air hose and a second air hose. The dual outlet manifold comprises a first air outlet and a second air outlet, both the air outlet and the second outlet being inline with filter unit such that the air filtered by the filter unit will be delivered both to the first air outlet and the second air outlet. The first air hose is then connected to the first air outlet and the second air hose is connected to the second air outlet. A connector end of the first air hose is connected to a second end of a first inline motorised fan module and a connector end of the second air hose is connected to a second end of a second inline motorised fan module. The first end of the first inline motorised fan module is then connected to a first helmet inlet of a first helmet and the first end of the second inline motorised fan module is connected to a second helmet inlet of the second helmet. In use, the originating fan is adapted to draw in air from the environment and blow the air through the filter unit. The filter unit 2002 is then adapted to filter dust, dirt, sediments or other particulate from the incoming air. The filtered air is then delivered towards the dual outlet manifold, dividing the incoming filtered air flow into a first airflow and a second airflow. A first airflow passes through the first air hose, towards the first inline motorised fan module, and finally to the first helmet. A second airflow passes through the second air hose, towards the second inline motorised fan module, and finally to the second helmet. This embodiment enables two users to be equipped with separate helmets that is provided with filtered air by a single PAPR system.

[0090]

[0088] In this configuration, the originating fan and the filter unit is adapted for delivering an air at a total flow rate of up to or exceeding 400 LPM. Simultaneously, the first airflow and the second airflow each has at least a flow rate of 200 LPM provided to the first helmet and the second helmet, respectively.

[0091]

[0089] In an embodiment, the originating fan is a battery-powered fan and includes a fan controller. The fan controller is configured to regulate and balance airflow between the first air hose and the second air hose based on a downstream pressure.

[0092]

[0090] The filter unit is modular and is replaceable by a high-capacity filter capable of supporting continuous operation at 400 LPM for a predetermined duration. In an embodiment, the controller is configured to provide an alert, reminding when to replace the filter unit.

[0093]

[0091] Each of the first inline motorised fan module is configured to supplement the delivered airflow of the originating fan to maintain comfort under increased respiratory demand or filter resistance. The dual outlet manifold further comprises a flow restrictor configured to maintain independent airflow rates to each user. In a preferred embodiment, the flow restrictor is a valve.

[0094]

[0092] In another embodiment, the powered air-purifying respirator system is configured as a centralised supply arrangement in which a single high-capacity fan and filter unit delivers airflow to more than two users via a multi-outlet manifold. Each outlet hose is connected to a corresponding inline motorised fan module as described in Figs. 1-7. In this configuration, the system ensures that each helmet receives a stabilised and compliant airflow level regardless of hose length differences, filter resistance, or the number of connected users. Such arrangements are particularly suited for group operations in environments such as underground rescue systems, tunnelling works, cleanroom facilities, or refuge chambers.

[0095]

[0093] According to a further aspect of the present invention, a method of supplying airflow to a helmet is provided.

[0096]

[0094] In one embodiment, the method comprises positioning a fan inline between an air hose and a helmet air inlet. As illustrated in Figs. 1-7, the inline motorised fan module 1000 comprises a housing 1001 with a first end 1002 and a second end 1003. The fan 1004 is positioned inside the housing such that, when the second end 1003 is coupled to an air hose 2003 and the first end 1002 is coupled to a helmet inlet 2041 , the fan is located inline along the airflow path. In this configuration, the method includes positioning the fan module 1000 between the hose and helmet to directly boost airflow before it enters the helmet.

[0097]

[0095] In one embodiment, the method comprises positioning the fan at or integrated with a helmet outlet connector. As shown in Fig. 8, the inline motorised fan module 1000 may replace the helmet connector 2004 of a conventional powered air-purifying respirator (PAPR) system 2000 (see Fig. 9). In such cases, the fan effectively becomes part of the helmet outlet, ensuring airflow is supplemented at the interface between the hose and the helmet.

[0098]

[0096] In one embodiment, the method comprises positioning the fan within the helmet cavity itself. In this embodiment (not shown in the drawings), the fan is mounted directly inside the helmet 2005 downstream of the inlet 2041 , allowing air to be boosted and distributed within the helmet chamber. This variation provides direct internal airflow control without requiring modification to the hose or connector assemblies.

[0099]

[0097] Once the fan is positioned, the method comprises operating the fan to supplement airflow delivered from a PAPR unit. As illustrated in Fig. 9, the PAPR system 2000 includes a primary fan 2001 and filter unit 2002 that deliver filtered air into the air hose 2003. When filter resistance increases, or when user demand rises, the method includes activating the inline fan 1004 (Figs. 1-7, 8) so that airflow volume delivered to the helmet 2005 is maintained or increased.

[0098] In one embodiment, the method further comprises maintaining airflow at a level suitable for respiratory protection, for example within a range of about 200 to 400 litres per minute. In a preferred embodiment, the airflow is maintained in the range of about 270 to 305 litres per minute. In another embodiment, the fan operates in a startup burst mode in which airflow exceeds 305 L / min for a predetermined duration before stabilising to a target range. This ensures rapid pressurisation of the helmet cavity and compliance with airflow standards even under high-demand conditions.

[0100]

[0099] The method further comprises drawing power for the fan. As depicted in Fig. 7, the electrical interface 1006 within housing 1009 may connect to a primary PAPR power source 2006 (Fig. 9), a helmet auxiliary port, or an external task-light output. In another embodiment, the method includes drawing power from a built-in power source 1005 positioned within the fan module housing 1001. This flexibility ensures the fan can be powered in multiple ways without requiring a dedicated supply.

[0101]

[0100] The method also comprises generating turbulent airflow within the helmet cavity. By directing the fan 1004 to create turbulence, the method enhances internal air mixing, reduces stagnant zones, and increases convective cooling across the user’s face and head. As described with reference to Figs. 1-5, the fan 1004 is mounted to rotate about axis A, thereby directing airflow toward the helmet inlet and into the helmet interior in a manner that induces turbulence.

[0102]

[0101] In one embodiment, the turbulence is user-adjustable via the control interface 1010 (Figs. 1-6), enabling the wearer to modify fan speed or airflow rate. In another embodiment, the method includes dynamically adjusting fan speed through a controller that senses downstream airflow pressure or flow rate.

[0103]

[0102] In one embodiment, the method is applied in a dual-user configuration. As described in the specification and shown schematically, a dual outlet manifold may divide filtered air from the PAPR unit into two hoses, each hose being connected to a respective inline motorised fan module 1000 (Figs. 1-7) before entering a corresponding helmet 2005 (Fig. 9). In this variation, the method includes positioning and operating a fan at each helmet to ensure that both users receive at least 200 L / min airflow, even under high filter load conditions.

[0104]

[0103] Accordingly, the method provides multiple implementation pathways — inline (Figs. 1-7), at the helmet outlet (Fig. 8), or within the helmet itself — while ensuring consistent delivery of safe and comfortable airflow to the user, regardless of filter loading, hose length, or environmental demands.

[0105]

[0104] In another embodiment, the method is applied in a centralised airflow system wherein a primary filtration and fan unit distributes filtered air through a multi-outlet manifold to a plurality of hoses. Each hose is connected to a helmet equipped with a supplemental fan according to the present method. The inline fans operate to stabilise airflow at each user’s helmet, ensuring that no user receives airflow below the minimum respiratory protection standard, even as the number of connected users or hose lengths vary.

[0106]

[0105] It will be appreciated that while certain embodiments describe airflow in the range of 270-305 L / min, the invention is not limited to this range. Depending on regulatory requirements or user demand, the airflow may be maintained at other suitable levels, for example between about 200 L / min and 400 L / min, or at higher levels as required by future standards.

[0107]

[0106] The following examples are provided to illustrate certain embodiments and applications of the invention. It will be understood that these examples are not intended to be limiting, and that variations and modifications may be made without departing from the scope of the invention as defined in the claims.

[0108] Examples

[0109] Example 1 : Tunnelling rescue system

[0110]

[0107] In one example, a high-capacity battery-powered fan and filter unit is provided at the entrance of an underground tunnelling worksite. The filtered air is delivered through a multi-outlet manifold to a plurality of air hoses. Each air hose is connected at a second end 1003 of a respective inline motorised fan module 1000, the first end 1002 of the fan module 1000 being connected to a helmet inlet 2041 of a helmet 2005 worn by a worker. The inline fan 1004 of each module supplements and stabilises airflow to the helmet 2005, thereby ensuring that each user receives a compliant airflow volume irrespective of hose length or the number of connected users. This arrangement enables several workers to connect simultaneously to the shared supply while maintaining respiratory comfort and safety.

[0111] Example 2: Refuge chamber protection

[0108] In another example, an underground refuge chamber is equipped with a centralised powered air-purifying respirator (PAPR) system comprising a primary fan 2001 and filter unit 2002 adapted to deliver filtered air through a multi-outlet manifold. A plurality of air hoses extend from the manifold, each hose being coupled to a second end 1003 of an inline motorised fan module 1000, with the first end 1002 connected to the helmet inlet 2041 of a helmet 2005. During an emergency event such as fire, blast, or dust overwhelm, the inline fan 1004 of each module is activated to supplement the centralised airflow, thereby maintaining airflow into each helmet 2005 at or above the minimum required level without triggering system performance alerts.

[0112] Example 3: Cleanroom and industrial use

[0113]

[0109] In a further example, a centralised battery-powered fan and filter unit supplies filtered air through a multi-outlet manifold to a plurality of workstations in a cleanroom or high-dust manufacturing facility. Each air hose is connected to a helmet inlet 2041 via an inline motorised fan module 1000. The inline fan 1004 of each module stabilises airflow directly at the helmet 2005, maintaining positive pressure within the helmet cavity and improving cooling for the user. This configuration reduces the need for individual powered units for each operator, while ensuring that airflow standards are maintained consistently across all connected users.

[0114] Example 4: Hot work and smelter operations

[0115]

[0110] In another example, a powered air-purifying respirator system includes a primary fan 2001 and filter unit 2002 configured to deliver filtered air at high flow rates through a multi-outlet manifold. Multiple air hoses extend from the manifold, each connected at a second end 1003 of an inline motorised fan module 1000. The first end 1002 of each module is connected to a helmet inlet 2041 of a helmet 2005 worn by operators working in smelting, furnace, or other hot work environments. The inline fan 1004 of each module supplements airflow directly at the helmet 2005, generating a turbulent airflow pattern within the helmet cavity that enhances heat dissipation and increases sweat evaporation. This reduces fatigue and improves user endurance under elevated temperature conditions while maintaining respiratory protection for multiple users connected to the same centralised supply.

[0116] Example 5: Disaster and emergency crew operations

[0111] In another example, a portable powered air-purifying respirator system comprising a high-capacity fan 2001 and filter unit 2002 is deployed to support disaster or emergency crews such as firefighters, collapse rescue teams, or bushfire smoke response units. The filtered air is distributed through a multi-outlet manifold to several hoses, each hose connected to a second end 1003 of an inline motorised fan module 1000. The first end 1002 of each module is connected to the helmet inlet 2041 of a helmet 2005 worn by a responder. The inline fan 1004 of each module supplements the shared airflow supply and ensures that each helmet 2005 receives stabilised and compliant airflow, even at the end of extended hose lines. This configuration enables safe, scalable respiratory protection for multiple operators working simultaneously in hazardous emergency environments.

[0117]

[0112] In one embodiment, the airflow assist module is deployed at the distal end of a steerable or robotic probe. The probe may be configured to navigate through cracks, voids, or collapsed structures, with the module delivering breathable air at the tip. In some arrangements, the probe includes a chamber or lumen behind the tip for passing capsules containing supplies such as medication, hydration fluids, or food, enabling support for trapped or isolated personnel. Advantageously, the airflow module ensures stable and positive airflow delivery into otherwise inaccessible spaces, while the steerable probe provides precise positioning in rescue environments.

[0118]

[0113] In another embodiment, the airflow assist module feeds an inflatable or expandable refuge chamber located at the end of a supply line. In use, the chamber may be deployed in confined or underground locations to provide a temporary safe space for one or more users. The airflow assist module ensures that positive airflow and respiratory safety are maintained within the chamber regardless of hose length, duct resistance, or back-pressure.

[0119]

[0114] In a further embodiment, the airflow assist module may be used to purify and deliver air into a vehicle cabin, enclosed space, or cavity. For example, the module may be connected via a hose to deliver filtered and stabilised airflow into an automobile, inspection vehicle, or other enclosed compartment, thereby reducing operator exposure to dust, fumes, or smoke while allowing mobile operation. In another arrangement, the module is attached to a portable hub powered by a 12V or 24V supply, enabling flexible deployment across industrial vehicles, temporary shelters, or residential environments.

[0115] In yet another embodiment, a centralised battery-powered hub is configured to feed multiple outlets, each coupled to a respective inline airflow assist module. The hub may be powered by common portable power supplies, such as 12V or 24V batteries, and can be deployed in field conditions to supply multiple users simultaneously. This configuration extends the applicability of the invention beyond welding helmets to group operations in hazardous environments, confined spaces, or mobile inspection tasks.

[0120] Markush Groups

[0121]

[0116] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognise that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0122] Chronological sequence

[0123]

[0117] For this specification, where method steps are described in sequence, the sequence does not necessarily mean that the steps are to be carried out in chronological order in that sequence, unless there is no other logical manner of interpreting the sequence.

[0124] Embodiments:

[0125]

[0118] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0126]

[0119] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Description of Embodiments are hereby expressly incorporated into this Description of Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[0127]

[0120] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0128] Different Instances of Objects

[0129]

[0121] As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0130] Specific Details

[0131]

[0122] In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0132] Terminology

[0133]

[0123] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. The invention is, however, not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

[0134]

[0124] As used herein the term “and / or” means “and” or “or”, or both.

[0125] As used herein “(s)” following a noun means the plural and / or singular forms of the noun.

[0135] Comprising and Including

[0136]

[0126] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e., to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[0137]

[0127] Any one of the terms: including orwhich includes or that includes as used herein is also an open term that also means including at least the elements / features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

[0138] Scope of Invention

[0139]

[0128] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0140]

[0129] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

[0141] Industrial Applicability

[0142]

[0130] It is apparent from the above, that the arrangements described are applicable to the welding industry as well as other industries including but not limited to firefighting and rescue, mining, tunnelling, construction, cleanroom environments, smelting, high- dust manufacturing, medical facilities, disaster response, and other hazardous or confined workspace operations.

Claims

Claims:

1. An inline motorised fan module for a helmet, comprising: a fan; a connector configured to couple the fan inline between a primary air hose and an inlet of the helmet, at or integrated with a helmet air outlet, or within a helmet cavity; and an electrical interface configured to draw power from a power source; wherein the fan is configured to increase the volume of airflow delivered into the helmet to improve respiratory comfort for a user.

2. The inline motorised fan module of claims 1 , wherein the power source is a power source of the PAPR unit, a helmet power source or auxiliary port, or an integrated power source of the module3. The inline motorised fan module of claim 1 , wherein the electrical interface is operable with a low voltage auxiliary output of the primary power source of the helmet.

4. The inline motorised fan module of claim 1 , wherein the fan is configured to maintain airflow in the range of approximately 200 to 400 litres per minute during operation.

5. The inline motorised fan module of claim 1 , wherein the fan is configured to operate in a startup burst mode providing airflow exceeding 305 litres per minute for a predetermined duration before reaching a predetermined airflow rate.

6. The inline motorised fan module of claim 1 , further comprising a user- operable control switch configured to adjust fan speed to maintain a desired airflow.

7. The inline motorised fan module of claim 1 , further comprising a coupling module configured for installation onto an existing powered air-purifying respirator system without modification to the primary air hose or helmet.

8. The inline motorised fan module of claim 1 , wherein the fan is configured to distribute airflow more evenly within the helmet cavity to enhance user comfort.

9. The inline motorised fan module of claim 1 , wherein the fan is an axial fan.

10. The inline motorised fan module of claim 1 , wherein the primary power source is a battery powered source.

11. The inline motorised fan module of claim 1 , wherein the connector is configured to couple the fan inline within an air hose, conduit, or duct used to convey breathable air to a respirator headpiece or confined workspace.

12. A powered air-purifying respirator system comprising: a primary fan and filter unit configured to deliver filtered air through an air hose; a head cover adapted to receive the airflow; and an inline fan module coupled between the air hose and the head cover; wherein the inline fan module is configured to supplement the primary airflow when the filter unit experiences increased resistance, thereby maintaining or increasing airflow into the head cover to reduce system performance alerts and improve respiratory comfort for a user.

13. The system of claim 12, wherein the fan generates a turbulent airflow pattern that enhances heat dissipation and increases sweat evaporation inside the helmet.

14. The system of claim 12, wherein the combined airflow from the primary fan and inline fan reduces user breathing effort and enhances endurance during extended use.

15. The system of claim 12, further comprising a control switch configured to maintain operational airflow under environmental conditions including high ambient temperature, elevated physical exertion, welding fume exposure, or airborne particulates.

16. The system of claim 12, wherein the inline fan includes a controller configured to adjust fan speed dynamically based on downstream airflow pressure or flow rate.

17. The system of claim 12, wherein the inline fan is an inline axial fan.

18. The system of claim 12, further comprising a battery powered source.

19. The system of claim 12, wherein at least one inline fan module is positioned within a hose, conduit, or duct of an air supply line upstream of the head cover, to compensate for airflow losses along the supply path.

20. The system of claim 12, wherein the primary fan and filter unit is replaced by or supplemented with an external breathable air supply line, including a long-line rescue or emergency air supply, the inline fan module being configured to compensate for line resistance and maintain stable positive pressure at the head cover.

21. The system of claim 20, wherein the primary fan and filter unit is battery- powered to enable portable, multi-user operation without fixed compressors or airline tethering.

22. The system of claim 12, further comprising an exhaust conduit or outlet configured to assist in removing exhaled carbon dioxide from the head cover in combination with the supplemental fan airflow.

23. A powered air-purifying respirator (PAPR) system comprising: a battery-powered fan and filter unit configured to deliver filtered air at a total flow rate of up to or exceeding 400 litres per minute; a dual outlet manifold configured to divide the airflow into at least two separate air delivery hoses; and at least two head covers, each adapted to receive airflow from one of the air delivery hoses; wherein the battery-powered fan and filter unit configured to simultaneously supply at least 200 litres per minute to each of the two head covers to support two users concurrently.

24. The system of claim 23, wherein the battery-powered fan unit includes a controller configured to regulate and balance airflow between the two hoses based on downstream pressure.

25. The system of claim 23, wherein the fan and filter unit include a replaceable high-capacity filter capable of supporting continuous operation at 400 litres per minute for a predetermined duration.

26. The system of claim 23, wherein each of the two head covers includes an inline fan module configured to supplement the delivered airflow to maintain comfort under increased respiratory demand or filter resistance.

27. The system of claim 23, wherein the dual outlet manifold includes flow restrictors or valves configured to maintain independent airflow rates to each user.

28. The system of claim 23, wherein the dual outlet manifold is replaced by or extended to a multi-outlet manifold configured to supply airflow to more than two head covers, each head cover including an inline fan module.

29. A method of supplying airflow in a powered air-purifying respirator (PAPR) system, the method comprising: providing a primary fan and filter unit configured to deliver filtered air through an air hose to a head cover or helmet worn by a user;positioning a supplemental fan inline between the air hose and a helmet air inlet, at or integrated with a helmet outlet connector, or within a helmet cavity; operating the supplemental fan to generate airflow into the head cover in addition to airflow from the primary fan and filter unit; and generating a turbulent airflow pattern within the helmet cavity to enhance cooling, reduce stagnant zones, and improve respiratory comfort for the user, including when resistance at the filter unit increases.

30. The method of claim 29, further comprising maintaining airflow at a level suitable for respiratory protection.31 . The method of claim 30, wherein the airflow is maintained in the range of about 200 to 400 litres per minute.

32. The method of claim 31 , wherein the airflow is maintained in the range of about 270 to 305 litres per minute.

33. The method of claim 31 or 32, wherein the airflow is maintained in a burst mode exceeding 305 litres per minute for a predetermined duration.

34. The method of claim 29, further comprising supplying electrical power to the supplemental fan from at least one of a power source of the PAPR unit or a helmet power source or auxiliary / task-light port, or an integrated battery of the supplemental fan.

35. The method of claim 29, wherein the supplemental fan is an axial fan.

36. The method of claim 29, further comprising controlling the supplemental fan by a user-operable switch to set airflow output.

37. The method of claim 29, further comprising positioning the supplemental fan inline within a hose, conduit, or duct of an air supply path remote from the helmet, to locally boost airflow and compensate for pressure losses along the path.

38. The method of claim 29, wherein airflow is supplied from a centralised filtration and fan unit to a plurality of helmets.

39. The method of claim 29, wherein the airflow is supplied from an external breathable air supply line located remote from the user, the supplemental fan being configured to compensate for resistance along the supply line.

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