Description:AN IMPROVED EXHALATION VALVE FOR RESPIRATORS

FIELD OF INVENTION

The present invention relates to the field of respirators, particularly to air-purifying respirators and more particularly to filtering facepiece respirators with a non-return exhalation valve, wherein the said respirators provide comfort to the wearer while breathing without compromising on the filtering of contaminants from the atmosphere.

BACKGROUND OF THE INVENTION

Respirators are devices designed to protect the wearer from inhaling hazardous substances or contaminants from the atmosphere. Air-purifying respirators use filters, cartridges, or canisters to remove gases, vapours, aerosols, or a combination of contaminants from the air. Filtering facepiece respirators are a type of air-purifying respirators which are disposable respirators that cover the nose and mouth.

To improve wearer comfort, some respirators include an exhalation valve which is a non-return valve that opens to allow exhaled air to escape through the valve while closing to force inhaled air through the filter. In filtering facepiece respirators, exhalation valves typically include a membrane composed of natural rubber, silicone, or neoprene. This membrane sits atop a support structure and lies beneath a plastic cover. During inhalations, the membrane closes against the support structure and blocks the opening, thereby not allowing airflow through the valve opening, thus protecting the wearer. During exhalations, when sufficient positive air pressure is achieved, the membrane lifts and the wearer’s unfiltered breath is expelled from the valve.

Although various designs of respirators with exhalation valves exist in the art as well as in the market, most of such respirators are either ineffective, or the ones which are effective, are expensive.

US patent application no. 13/323,130 discloses a respirator whose exhalation valve comprises a flap that has a surface that has been ablated. The said patent document claims that through the use of an ablated flap, the valve flap can be fashioned to remain closed under any orientation but also to open with minimal force or pressure from the wearer's exhaled air. The patent document further discusses that when a conventional button-style valve opens, the radial nature of the valve causes the flap to resist opening around its whole circumference. Thus, only a portion or segment of the flap tends to lift from the seal surface during use. However, it claims that the flap illustrated by the invention disclosed by the said patent application may alleviate this resistance to opening issue. The ablated areas of the flap disclosed therein have less material and thus encourage bending in those areas, which may enable the whole circumference of the flap to be lifted from the seal surface during use. However, while the invention may have improved the wearer’s comfort, such enablement of the whole circumference of the flap to be lifted from the seal surface increases the possibility of allowing particles/ contaminants inside the respirator.
Indian patent application no. 1197/MUM/2013 discloses a butterfly type exhalation valve wherein a butterfly type diaphragm is present within a top cap/lid and bottom seat to hold the valve in a particular position such that the pin in the valve’s bottom/base is of a precise diameter so as to not create any distortion or surface tension on the diaphragm. In the disclosed invention, the solid pin at the centre of the exhalation valve’s bottom seat positions the diaphragm and holds it at the centre as fulcrum, so that the butterfly wings diaphragm shall open out during exhalation process from the side edges whereby four conical slots allow passage of exhaled air through the open space. The said invention further discloses a vertical protruded ribbed restrictor that prevents the diaphragm from getting locked in an open position. However, while the restrictor holds the diaphragm in the centre, it also creates a force on the diaphragm thereby reducing the easy flow of the exhaled air which in turn reduces the wearer’s comfort.

Patent document EP11723590A discloses a one-way valve for use in the inhalation and/or exhalation flow path of respiratory protection equipment wherein the said valve consists of a housing defining a conduit and a circumferential array of three flexible flaps, each extending inwards from the conduit wall and in the direction away from the inlet end of the valve. The patent document further discloses that under a pressure differential in the opening direction of the valve, each flap is adapted to flex outwards towards the conduit wall and under a reverse pressure differential, the free edge of each flap is adapted to press in sealing contact with the respective portions of the free edges of the neighbouring flaps. The document further elaborates that the higher the pressure differential, the tighter the contact will be between the flaps and the contact area between them will also tend to increase the harder they are pressed together, so the better the seal. It claims that the reverse flow though the valve is therefore reliably blocked by this contact between the flaps without the need for any additional valve seat. However, in reality, this would put a strain on the wearer as the pressure differential would depend on the inhalation and exhalation of the wearer.

The above cited prior art documents, however, do not provide an exhalation valve which is simultaneously efficient in the functionalities of giving the wearer increased comfort while at the same time being contamination free. Therefore, there is a need in the art to provide an improved exhalation valve for respirators such that the said exhalation valve provides maximum possible comfort to the wearer while simultaneously ensuring that there is no reverse flow of air through the exhalation valve i.e., that contaminants do not enter inside the respirator.

OBJECTIVES OF THE INVENTION

The primary objective of the present invention is to provide an improved exhalation valve for respirators which provides maximum possible comfort to the wearer while simultaneously ensuring that there is no reverse flow of air through the exhalation valve i.e., that contaminants do not enter inside the respirator.

Another objective of the present invention is to provide an improved exhalation valve for respirators which is cost effective.
Yet another objective of the present invention is to provide an improved exhalation valve for respirator which is easy to manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates the side view of the improved exhalation valve (100) of the present invention.
Figure 2 illustrates the underside component (101) of the improved exhalation valve (100) of the present invention.
Figure 3 illustrates the perspective view of the cover (104) of the improved exhalation valve (100) of the present invention.
Figure 4 illustrates the membrane (106) of the improved exhalation valve (100) of the present invention.

REFERENCE NUMERALS FOR THE FIGURES

100 – Improved exhalation valve of the present invention
101 – Underside component of the improved exhalation valve (100)
101A, 101B, 101C – Fan-shaped blades of the underside component (101)
101D, 101E, 101F – Sector-shaped apertures formed between 101A, 101B, 101C
101a, 101b, 101c – Respective centre pins of 101A, 101B, 101C
102 – Centre pin of the underside component (101)
103 – Flange of the underside component (101)
104 – Cover of the improved exhalation valve (100)
104A, 104B, 104C – Stepped ribs present on the inner side of the cover (104)
104a, 104b, 104c – Curved slits present on the circumferential side of the cover (104)
105 – Flange of the cover (104)
106 – Membrane present between the underside component (101) and the cover (104)
106A, 106B, 106C – Lobes of the membrane (106)
106a, 106b, 106c – Space between the lobes (101A, 101B, 101C)

SUMMARY OF THE INVENTION

The instant invention discloses an improved exhalation valve (100) for respirators, the said improved exhalation valve (100) comprising of an underside component (101) with a centre pin (102) and a flange (103); a cover (104) with a flange (105) which complements the flange (103) so as to get locked; and a membrane (106) wedged between the said underside component (101) and the cover (104); characterised in that:
(i) the said underside component (101) comprises at least three fan-shaped blades (101A, 101B, 101C) diverging from its centre, forming three sector-shaped apertures (101D, 101E, 101F) in between, wherein each of the said fan-shaped blades (101A, 101B, 101C) comprises a centre pin (101a, 101b, 101c), the said centre pins (101a, 101b, 101c) being shorter relative to the centre pin (102);
(ii) the said membrane (106) is cloverleaf shaped, comprising at least three lobes (106A, 106B, 106C), each of the said lobes (106A, 106B, 106C) separated by an equidistant space (106a, 106b, 106c) from the adjacent lobes, wherein the said membrane (106) is pinned at the centre pin (102) of the said underside component (101) such that the lobes (106A, 106B,106C) correspond to the sector-shaped apertures (101D, 101E, 101F) and the spaces (106a, 106b, 106c) correspond to the fan-shaped blades (101A, 101B, 101C) in a manner that the centre pins (101a, 101b, 101c) protrude through the spaces (106a, 106b, 106c); and,
(iii) the cover (104) comprises at least three stepped ribs (104A, 104B, 104C) at its inner side and at least three curved slits (104a, 104b, 104c) on its circumferential side such that when the flange (105) is locked with the flange (103), the said stepped ribs (104A, 104B, 104C) lock the lobes (106A, 106B, 106C) from opening fully.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this specification, the use of the word “comprise” and variations such as “comprises” and “comprising” may imply the inclusion of an element or elements not specifically recited.

The invention disclosed in the present specification overcomes the shortcomings mentioned above in the prior art and achieves the objectives elucidated above wherein the novelty of the improved exhalation valve (100) for respirators disclosed herein lies in the ability of the membrane (106) to open freely even with less efforts from the wearer during exhalation, while at the same time ensuring that the membrane (106) does not open fully to allow particles inside the respirator. This is achieved through the unique cloverleaf shaped design of the membrane (106) synergistically combined with the stepped ribs (104A, 104B, 104C) present on the inner side of the cover (104).

Such an arrangement provides a seat of sorts to the lobes (106A, 106B, 106C) of the membrane (106) such that when air blows in the direction of the underside (101) to the cover (104), the lobes (106A, 106B, 106C) are lifted just until the step on the stepped rib (104A, 104B, 104C) of the cover (104) blocks further lifting of the lobes, and when the air blows from the other direction i.e., from the cover (104) to the underside component (101), the lobes (106A, 106B, 106C) are locked and do not lift. Therefore, not only is the exhalation valve (100) unidirectional, but it also efficiently controls the membrane (106) from lifting too much; rather, lifts just enough to discharge the air exhaled by the wearer, through the curved slits (104a, 104b, 104c) present on the circumferential side of the cover (104), without allowing particles to enter via the said slits (104a, 104b, 104c). This results in a non-return valve design wherein the valve opens just enough only during exhalation and not during inhalation.

The unique design of the membrane (106) is such that the cloverleaf shaped membrane (106) possesses at least three lobes (106A, 106B, 106C), each of the said lobes (106A, 106B, 106C) separated by an equidistant space (106a, 106b, 106c) from the adjacent lobes. The said membrane (106) is pinned at the centre pin (102) of the underside component (101) such that the lobes (106A, 106B,106C) correspond to the sector-shaped apertures (101D, 101E, 101F) and the spaces (106a, 106b, 106c) correspond to the fan-shaped blades (101A, 101B, 101C) in a manner that the centre pins (101a, 101b, 101c) protrude through the spaces (106a, 106b, 106c). When the cover (104) is press-fitted to the underside component (101) such that the flange (105) locks with the flange (103), the stepped ribs (104A, 104B, 104C) lock the lobes (106A, 106B, 106C) from opening fully, i.e., during exhalation of the wearer when there is air flowing in the direction of the underside component (101) to the cover (104), the lobes (106A, 106B, 106C) open freely up until the membrane (106) meets the step, beyond which it is restricted from opening. The cloverleaf shape of the membrane (106) enables the exhalation valve (100) to provide maximum possible comfort to the wearer as the flow of air is evenly distributed for exhalation through the valve, unlike in the prior art, which in turn reduces the efforts required by the wearer during exhalation.
In the preferred embodiment of the improved exhalation valve (100) for respirators disclosed herein, the membrane (106) has three lobes (106A, 106B, 106C).

In the preferred embodiment of the improved exhalation valve (100) for respirators disclosed herein, the membrane (106) is made of rubber or silicone.

In the preferred embodiment of the improved exhalation valve (100) for respirators disclosed herein, the underside component (101) and the cover (104) are made of plastic.

What has been described and illustrated herein is a preferred embodiment of the invention along with some of its components. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognise that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.
, Claims:1. An improved exhalation valve (100) for respirators, comprising of: an underside component (101) with a centre pin (102) and a flange (103); a cover (104) with a flange (105) which complements the flange (103) so as to get locked; and a membrane (106) wedged between the said underside component (101) and the cover (104); characterised in that:
(i) the said underside component (101) comprises at least three fan-shaped blades (101A, 101B, 101C) diverging from its centre, forming three sector-shaped apertures (101D, 101E, 101F) in between, wherein each of the said fan-shaped blades (101A, 101B, 101C) comprises a centre pin (101a, 101b, 101c), the said centre pins (101a, 101b, 101c) being shorter relative to the centre pin (102);
(ii) the said membrane (106) is cloverleaf shaped, comprising at least three lobes (106A, 106B, 106C), each of the said lobes (106A, 106B, 106C) separated by an equidistant space (106a, 106b, 106c) from the adjacent lobes, wherein the said membrane (106) is pinned at the centre pin (102) of the said underside component (101) such that the lobes (106A, 106B,106C) correspond to the sector-shaped apertures (101D, 101E, 101F) and the spaces (106a, 106b, 106c) correspond to the fan-shaped blades (101A, 101B, 101C) in a manner that the centre pins (101a, 101b, 101c) protrude through the spaces (106a, 106b, 106c); and,
(iii) the cover (104) comprises at least three stepped ribs (104A, 104B, 104C) at its inner side and at least three curved slits (104a, 104b, 104c) on its circumferential side such that when the flange (105) is locked with the flange (103), the said stepped ribs (104A, 104B, 104C) lock the lobes (106A, 106B, 106C) from opening fully.

2. The improved exhalation valve (100) for respirators as claimed in Claim 1 wherein the membrane (106) material is rubber or silicone.

3. The improved exhalation valve (100) for respirators as claimed in Claim 1 wherein the underside component (101) and the cover (104) are press fitted.

4. A respirator comprising the said exhalation valve (100).