Powered air respirator kit

A powered air respirator kit comprising visor (9) removably attachable to a front edge of a safety helmet (4), a drive unit (1) removably attachable to said safety helmet (4), at least one filter module removably attachable to said safety helmet such that, in use, a fluid flow path is defined through said filter module to a space defined between a user's face and an inner surface of said visor, the kit further comprising a power module (10) removably attachable to said safety helmet and, in use, electrically connectable to said drive unit (1).

This application is a national stage filing under 35 U.S.C. 371 of International Application No. PCT/GB2016/052550, filed Aug. 18, 2016, which claims priority to United Kingdom Application No. 1515081.6, filed Aug. 25, 2015. International Application No. PCT/GB2016/052550 was published under PCT Article 21(2) in English, the entire teachings of which are incorporated by reference herein.

This invention relates generally to a powered air respirator kit for use in atmospheres that are contaminated with dust fumes, gases or vapours that may be hazardous to health.

Many different types of respirator apparatus have been proposed and used in various fields for many years. Such apparatus can be considered in two different categories:Head mounted systems; andWaist mounted systems.

Head mounted systems tend to be bespoke respirator systems, having a helmet incorporating a visor and carrying a drive and filter module, with or without a power source. Such systems tend to be heavy and uncomfortable to wear and, as a result, there is a constant drive to reduce the weight of the overall assembly. In known such bespoke respirator systems, this has usually involved a reduction in thickness and/or coverage of the helmet, thus reducing its capacity for protection and eliminating the ability for such helmets to have the required statutory safety certification of normal safety helmets.

An alternative solution to the above-mentioned weight problem has been proposed, in the form of waist mounted systems, wherein the helmet is still provided with an integral visor, but the respirator assembly itself is carried by the user around their waist, with a pipe or duct extending between an opening in the visor and the respirator assembly. Such systems are complex and the extension of a pipe along the user's upper body can restrict their movement. In both cases, and in use, the operative must utilise the head protection afforded by the system itself, rather than being able to use the safety helmet they normally use and feel most comfortable in.

It is an object of aspects of the present invention to address at least some of these issues, and provide a powered air respirator assembly that can be removably fitted to a standard safety helmet, having full statutory safety certification, as and when the need arises, and removed again when the apparatus is no longer required.

In accordance with an aspect of the present invention, there is provided a powered air respirator kit comprising visor removably attachable to a front edge of a safety helmet, a drive unit removably attachable to said safety helmet, at least one filter module removably attachable to said safety helmet such that, in use, a fluid flow path is defined through said filter module to a space defined between a user's face and an inner surface of said visor, the kit further comprising a power module removably attachable to said safety helmet and, in use, electrically connectable to said drive unit.

The kit may comprise a gasket which is removably attachable to a front edge of said safety helmet, and is configured to removably receive at least a portion of said drive unit and/or said filter module. The gasket may be of a curved configuration so as to extend around a corresponding curved portion of said front edge of said safety helmet.

In an exemplary embodiment, at least one filter module may be mounted on said drive unit such that, in use, said at least one filter module is removably attachable to said safety helmet via said drive unit. A filter module may be mounted on each side of said drive unit, and said drive unit may be removably attachable to said safety helmet at a generally central location at the front edge thereof.

The power module may be configured to be removably attachable at the rear of said safety helmet. In an exemplary embodiment, the power module may be configured to be removably attachable to a rear strap of an inner harness of said safety helmet.

The kit may comprise a sealing skirt configured to be removably attached to the side and lower edges of said visor.

In an exemplary embodiment, the kit may comprise a pair of adaptors, each being removably connectable to a side surface of said safety helmet, and an elongate visor carrier member on which said visor can be mounted and having, at each distal end thereof, connector members configured, in use, to pivotally engage with respective said adaptors. In this case, the kit may further comprise a pair of ear defender assemblies, each including a connector member, wherein said connector members are configured to adjustably engage with respective said adaptors.

The visor carrier may comprise a curved band configured, in use, to be connected to said front edge of said safety helmet. The visor carrier may comprise a peak portion extending substantially horizontally from a generally central portion of said band, wherein, in use, said visor extends downwardly from said band such that a first portion of said peaked portion extends beyond a front edge of said visor and a second portion of said peaked portion extends between the rear of the band and the front edge of the safety helmet. In this case, the gasket may comprise a grill member extending substantially horizontally therefrom, wherein said grill member engages with said second portion of peaked portion of said visor carrier, in use. The second portion of said peaked portion of said visor carrier may include at least one opening therein, and said gasket is configured to, in use, receive said drive unit such that a fluid flow path is defined between said at least one filter module and said opening. The at least one opening may be provided with a guidance duct configured to direct air away from a user's eyes onto a rear surface of said visor, in use. The duct may comprise a bisected pre-plenum portion and at least one turning vane on one side, the opposing side being at least partially open.

In an exemplary embodiment, at least one light emitting device may be provided in or on said first portion of said peaked portion of said visor carrier, said light emitting device being electrically connectable to said power module, said drive unit and/or said at least one filter module. At least one angled transmission vane may be provided between the band and a lower surface of said first portion of said peaked portion of said visor carrier, said transmission vane being configured to guide light from said at least one light emitting device to an inner surface of said visor, in use. Said at least one transmission vane may be formed of transparent plastic material. In an exemplary embodiment, a plurality of light emitting devices may be provided in or on the first portion of said peak portion of said visor carrier, wherein a plurality of respective transmission vanes, arranged substantially parallel to each other, may be provided for guiding light from each respective light emitting device to an inner surface of said visor, in use. The or each said transmission vane may have an angled edge comprising two sections, wherein each section extends at the same angle from the lower surface of the peaked portion and the band respectively. The angle may be substantially 55°.

In accordance with another aspect of the present invention, there is provided a visor carrier for a kit as described above, said visor carrier comprising a curved band configured, in use, to be removably connected to said front edge of said safety helmet, and a peak portion extending substantially horizontally from a generally central portion of said band, wherein, in use, said visor extends from said band such that a first portion of said peaked portion extends beyond a front edge of said visor and a second portion of said peaked portion extends between the rear of the band and the front edge of the safety helmet.

In accordance with another aspect of the present invention, there is provided gasket for a kit as described above and for use with the visor carrier described above, the gasket being configured, in use, to be removably connected to said front edge of said safety helmet and having a curved configuration so as to extend, in use, around a corresponding curved portion of said front edge of said safety helmet.

In accordance with yet another aspect of the present invention, there is provided a powered air purifying respirator comprising a safety helmet having a visor, a drive unit and at least one filter module removably attached thereto.

The drive unit may be removably attached to said safety helmet at a front edge thereof, and further comprising a power module removably attached to a rear portion of said safety helmet.

Referring toFIG. 1of the drawings, a powered air (purifying) respirator PAPR kit according to an exemplary embodiment of the present invention comprises a drive and filter unit1, a visor gasket2, a visor carrier3and a visor9.

Referring additionally toFIG. 2of the drawings, the drive and filter unit1comprises a generally central drive unit consisting of a housing or cowl10within which is housed a volute12defining a generally central horizontal channel therethrough, between openings in the side edges of the cowl10. A motor14is mounted within the volute channel and communicably coupled at each distal end of its shaft to a respective impeller16. A drive PCB18is mounted at the base of the volute12, for driving the motor14(and, optionally, generating signals for operating an indicator LED as will be described later). The impellers16are housed within respective recesses17at each end of the volute12and a respective volute lid20is used to cover the end of each recess17, each volute lid defining a generally central opening defining a fluid flow path for the respective impeller, in use.

On each side of the drive unit, there is provided a filter assembly22. Referring additionally toFIG. 3of the drawings, each filter assembly is communicably coupled to the fluid flow path from a respective impeller16via a filter gasket24coupled to a respective volute lid20. As shown inFIG. 3, each filter assembly22additionally comprises a finger mesh26, a filter case27, some form of filter media28, a filter grill29, a pre-filter member30and a pre-filter cover31. However, it will be appreciated by a person skilled in the art that other filter assembly configurations can be used, and the present invention is not necessarily intended to be limited in this regard.

Referring back toFIG. 1of the drawings, it can be seen that, in the assembled form, the drive and filter unit1is curved to generally correspond with the curve of the outer front wall of a safety helmet4.

The visor gasket2comprises a similarly curved gasket member having a grill member2aextending substantially horizontally from a generally central front portion thereof. The visor carrier3comprises a curved band member having, at each distal end, an arm3apivotally mounted thereon. Each arm3aterminates in a connector member3b. The connector members3bare configured to enable the visor carrier3to be hingedly connected to the safety helmet4by means of a pair of adaptors (4a—FIG. 4) removably clipped thereon.

The generally central front portion of the band member of the visor carrier3is provided with an integral peaked portion comprised of a front portion that extends forward of the band member and is outwardly curved, and a rear portion that extends rearward of the band member and is inwardly curved to generally correspond with the curved front edge of the safety helmet4. A pair of openings3cis provided in the rear portion.

In the assembled form, and referring additionally toFIG. 4of the drawings, the visor gasket2is removably mounted to the front edge of the safety helmet4and the drive and filter unit is coupled to the gasket such that it sits across the front surface of the safety helmet4, and such that a fluid flow path is defined from the atmosphere, through the filter assemblies, down through the grill member2ain the visor gasket. In use, the impellers, driven by the motor, draw air from the atmosphere through the filter assemblies and direct it out through the grill member2a.

The visor carrier3is pivotally mounted at the side edges of the helmet4, via the connector members3band adaptors4a, and the visor9is mounted to the visor carrier3. The visor9is thus pivotable (via the visor carrier3) between an operative position, in which it covers a user's face(shown), and an inoperative position in which the visor9is pivotally lifted up and away from the user's face. A removable sealing skirt11may be provided around the side and lower edges of the visor9so as to provide a seal between the visor9and the user's face, if required and depending on the environment in which the assembly is to be used. In use, air drawn through the filter assemblies and directed through the grill member2aof the visor gasket2by the impellers16, passes through the openings3cinto the space defined between the rear or inner surface of the visor9and the user's face.

Referring back toFIG. 1of the drawings, a powered air purifying respirator kit according to an exemplary embodiment of the invention further comprises an adaptor5which can be removably clipped at a side edge of the safety helmet4. The adaptor5is, in this case, configured not only to receive the connector members3bat the end of the visor carrier arms3a, but also ear defender assemblies (discussed below), so that their configuration may be different to that required if only the visor (and not the ear defenders) are required to be mounted to the safety helmet4. The visor carrier connector members3bare connected to the respective adaptors5via a visor pivot fastener7. An ear defender assembly8is subsequently connectable to the adaptors5to complete the assembly process.

Referring additionally toFIG. 4of the drawings, a battery box assembly19is removably mountable on the rear strap21of the helmet harness and acts to counter-balance the weight of the drive and filter unit1at the front. A power cable (not shown) is provided to electrically connect the battery box19to the drive PCB18of the drive unit. Thus, the modular kit can be mounted as shown inFIG. 4, for use as required and only the elements thereof required for a particular job need to be mounted (i.e. only the visor, the visor and sealing skirt assembly, or the visor and ear defenders). When the kit is not in use, it can be removed from the safety helmet4altogether and the safety helmet, which can be a standard safety helmet conforming to safety standards such as EN397 certification, can be used as such.

Referring now toFIG. 5of the drawings, the lower surface of the rear part of the peaked portion of the visor carrier3is provided with air flow directing vents30in respect of the openings3c, and a set of light transmission vanes32on the lower surface of the front portion of the above-mentioned peaked portion of the visor carrier3.

Considering first the transmission vanes32, these comprise a set (in this case, three) angled ‘light pipes’ formed of transparent plastic (e.g. ABS). A set of three warning LEDs34are provided in the front portion of the above-mentioned peak portion, in this case, a red LED, a blue LED and a green LED may be provided. The LEDs34are intended to provide information to a user (and others) as to the condition of the battery and/or the filter assemblies, but their actual position relative to the user's eyes (in use) is such that they are barely, if at all, visible to the user. Thus, the transmission vanes32are configured to refract the output of the LEDs34downward from the peaked portion of the visor carrier3toward the inner surface of the visor9which, in turn, reflects the light back to the user's eyes, thereby providing a heads-up indicator display to the user, during normal use. The angle of the vanes32is such that they provide an internal reflection surface at an angle of incidence greater than the critical angle, as illustrated inFIG. 6of the drawings. Thus, each vane32is angled from a point closest to the front of the peaked portion (on the lower surface) to the curved band3d. Referring toFIG. 7of the drawings, an optimum profile of the angled edge of each vane32to achieve the desired result is illustrated. As shown, the angle between the edge and the lower surface of the peaked portion is around 55° in this case and changes at around a third of the way along the edge such that the angle between the edge and the vertical surface defined by the band3dis also around 55°. Thus, more generally, an advantageous configuration of the angled edge may be in the form of two angled portions, a first portion at a first angle relative to the lower (horizontal) surface of the peaked portion and a second portion at a second angle relative to the vertical (inner) surface of the carrier band3d; and, in an exemplary embodiment, the first and second angles may be substantially identical. However, other suitable angle configurations may be apparent to a person skilled in the art and the present invention is not necessarily intended to be limited in this regard.

The pattern of warning light indicators may, for example, be as follows:

Static green (only)All systems goodStatic green and flashing redBattery approaching flatFlashing red (only)Flat batteryStatic green and flashing blueBlocking filterFlashing blue (only)Blocked filter
but the present invention is not necessarily intended to be in any way limited in this regard.

Referring now toFIG. 8of the drawings, the air flow directing vent members30are intended to prevent irritation and drying of a user's eyes by directing air, drawn by the impellers through the filter assemblies and into the space between the inner surface of the visor9and the user's face, away from the user's eyes toward the inner surface of the visor9. As shown, the vents30may, advantageously, each comprise a bisected pre-plenum portion30acombined with a turning vane30b, with each vent having an open side to maintain optimal cross-sectional open area such that flow is directed away from the eyes and attached to the visor9, minimising recirculation, whilst pressure against the impellers is not overly increased.

It will be apparent to a person skilled in the art, from the foregoing description, that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined by the appended claims.