WO2008136021A1

WO2008136021A1 - Inlet connector of an m90 nbc face mask provided with means for obtaining low respiratory resistance values both during inhaling and exhaling phases

Info

Publication number: WO2008136021A1
Application number: PCT/IT2007/000323
Authority: WO
Inventors: Giuseppe Galli
Original assignee: Officine Meccaniche Galli S.R.L.
Priority date: 2007-05-02
Filing date: 2007-05-02
Publication date: 2008-11-13
Also published as: EP2144675A1; DE602007013473D1; EP2144675B1; ATE502678T1

Abstract

The inlet connector of an NBC face mask of the' type comprising two openings, a lower inhalation opening formed by an mouthpiece onto which an NBC filter is fixed, and an upper exhalation opening, characterised by providing in its interior, a chamber in communication with said mouthpiece, which is equipped with means adapted to seal it in order to prevent the entry of external air into the face mask when the filter is removed from the mouthpiece, and additional means adapted to operate as an inhalation valve for increasing the entry of already filtered air into the face mask when the filter is fixed onto said mouthpiece. Exhalation and inhalation functions are thus performed more easily, both with and without the filter inserted, thus ensuring that the face mask has improved comfort characteristics and ease of use.

Description

INLET CONNECTOR OF AN M90 NBC FACE MASK PROVIDED WITH MEANS FOR OBTAINING LOW RESPIRATORY RESISTANCE VALUES BOTH DURING INHALING AND EXHALING PHASES

*****

The present invention relates to the NBC protection sector and in particular, refers to an improvement to the inlet connector of a face mask, forming the subject of patent application N° RM2002A000426 in the name of the same applicant, in order to respond to the additional request for a face mask having the following inhalation and exhalation values for different air delivery capacities.

- Inhalation resistance (with empty filter applied to the face mask) :

ΔP < 0.5 mbar at 30 L/minute; ΔP < 1.5 mbar at 95 L/minute; ΔP < 4.3 mbar at 160 L/minute;

- Inhalation resistance (with filter applied to the face mask) :

ΔP < 2.5 mbar at 30 L/minute; ΔP < 6.0 mbar at 95 L/minute; ΔP < 12.0 mbar at 160 L/minute;

- Exhalation resistance: ΔP < 3.0 mbar at 160 L/minute.

Currently, traditional inlet connectors provide the use of a single membrane which fulfils both the role of inhalation valve, when the filter is fixed onto the inlet, and the role of a seal, when the filter is removed from the inlet connector itself.

Said membrane is part of a moveable unit which is mounted, by snap fastening, onto the end of the mouthpiece, and comprises a rubberised leaf, an inhalation seat and a disk, wherein the leaf and the disk are located at the end of a sliding pin which crosses through the inhalation seat. A solution of this kind proved unsatisfactory for a number of reasons.

A first drawback consists of the fact that the air flow coming from the filter and entering into face mask is not facilitated considering the reduced diameter of the membrane.

A second drawback is due to the fact that when the airflow passes through the inhalation seat, said membrane can only bend within certain limits at its edges since it is fixed to the inhalation seat. The main scope of the present invention is that of overcoming said drawbacks, by providing an inlet connector provided with means allowing the user to perform the exhaling and inhaling functions more easily, both with and without the filter inserted, thus ensuring that the face mask has improved comfort characteristics and ease of use.

This has been attained by providing, within the inlet connector, a chamber, in communication with the mouthpiece so as to allow the insertion of a larger membrane, leaving to the existing membrane the opening/closing functions depending on the presence or not of the filter.

Said chamber is essentially formed by a hollow cylindrical body delimited at its lower end by the inhalation membrane, and at its upper end by the inhalation seat, which is closed by the sealing valve. In other words, the inhalation membrane no longer belongs to the moveable unit, and its new position allows a greater airflow to enter into the chamber, when the filter is fixed onto the mouthpiece, and to reach the inside of the face mask, while the gasket which was fixed onto the seat is now fixed onto the disk, having sole sealing function.

A better understanding of the invention will be obtained from the following detailed description and with reference to the enclosed drawings which show, as an example only, a preferred embodiment. In the drawings: figure 1 shows a vertical section of a traditional inlet connector; figure 2 is a vertical section of the invention.

With reference to figure 1, the inlet connector of the known type provides a single membrane 1 which is an integral part of a moveable unit which is mounted by snap fastening onto the bottom of the mouthpiece and which comprises a leaf 2 and a disk 4, both fixed to a centrally located pin 5, at its upper and lower ends respectively, which pin 5 runs along its own axis crossing an inhalation seat 3.

The membrane 1 is located below said inhalation seat 3 and lies substantially adjacent to it. Said membrane is fixed onto the inhalation seat 3.

The leaf 2 is positioned inside the mouthpiece, close to its bottom, while the disk 4 lies below the membrane and the inhalation seat 3 is in contact with the bottom of the mouthpiece itself.

The moveable unit is controlled by a contrast spring 6 positioned between the leaf 2 and the inhalation seat 3: said spring 6 is compressed when the filter to be fixed to the mouthpiece is pressed against the leaf, and it extends when the filter is removed. In the first case, the disk 4 is moved away from the membrane 1 and facilitates the entry of air coming from the filter, into the face mask, allowing the user to inhale. In the second case, the disk 4 is returned behind the membrane 1 so that the latter is closed tightly against the inhalation seat 3, preventing the inlet of contaminated external air into the face mask, avoiding any possibility of the user breathing it after removing the filter.

The inhalation seat 3 comprises two concentric tubular elements, delimiting an area through which the air coming from the filter passes. Said area is subdivided into a plurality of portions by means of radial arms which extend from the outer tubular element to the inner tubular element, by means of which the latter is made integral with the former.

The upper end of the outer tubular element ends in a peripheral flat ring 7 which is in contact with the bottom of the mouthpiece.

The inner tubular element, which is not visible in the drawing, acting as a guide for the pin 5 which passes through the same.

With reference to figure 2, according to the present invention, the herein described inlet connector provides a chamber in communication with the mouthpiece which is substantially formed by a hollow cylindrical body. The upper end of said chamber is delimited by the inhalation seat 3 and its lower end by the membrane 1 acting as an inhalation valve.

The inhalation membrane 1 is thus completely independent from the moveable unit . It is likewise evident that the disk 4 located at the lower end of the moveable unit sliding pin 5 does not interfere with the inhalation membrane 1.

According to a particular characteristic of the invention, in order to seal the inhalation seat 3, when the filter is removed, the disk 4 is provided with a closing valve 8.

The inhalation membrane 1 is mounted by means of a rivet 9 at the centre of a spider which is supported by a ring support 10, integrally connected to the inner wall of the chamber by means of suitable arms. In this way the membrane 1 can bend freely according to the respiration phases, being free from any constraints at its edges.

Due to the large diameter of the inhalation membrane 1, the presence of said ring support 10 has the task of preventing it from bending unusually or becoming deformed over time.

Until the NBC filter is inserted onto the mouthpiece, the disk 4 seals the inhalation seat 3 by means of the closing valve 8 so as to prevent external air from entering into the chamber and consequently into the face mask.

When the NBC filter is inserted onto the mouthpiece, it presses on the leaf 2 and, by overcoming the pressure of the contrast spring 6, makes the pin 5 slide downwards. In this way, the disk 4, on which the sealing valve 8 is mounted, also moves downwards and, by moving away from the inhalation seat 3, allows already filtered air to enter into the chamber. The user's breathing makes the inhalation membrane 1 bend so as to fulfil the entry of the required air quantity.

Advantageously, the inhalation membrane 1 has a diameter greater than that of the traditional membrane, whose diameter is substantially equal to that of the disk 4 used in known inlet connectors, which, given the same thickness, allows to increase the flexibility of the membrane 1, thus allowing the entry of a greater already filtered airflow into the face mask.

It should also be observed that the diameter of the inhalation seat 3 is enlarged with respect to the traditional model, further increasing the airflow entry into the face mask.

According to the invention, a second advantage is given by the fact that, in order to guarantee improved air expiration from inside the face mask towards the outside, an expiration membrane is provided for, being located outside of said chamber, and having a greater diameter with respect to the one used in the known inlet connector.

The present invention has been described and illustrated by means of a preferred embodiment, but it is obvious that a person skilled in the art may be able to bring about modifications and/or technically equivalent substitutions without departing from the scope of protection of the present industrial patent.

Claims

CLAIMS :

1. The inlet connector of an NBC face mask of the type comprising two openings, a lower inhalation opening formed by a mouthpiece onto which an NBC filter is fixed, and an upper exhalation opening, characterised by providing in its interior, a chamber in communication with said mouthpiece, which is provided with means adapted to seal it in order to prevent entry of external air into the face mask when the filter is removed from the mouthpiece, and additional means adapted to operate as an inhalation valve for increasing the entry of already filtered air into the face mask when the filter is fixed onto said mouthpiece .

2. The inlet connector according to the preceding claim, characterised in that the chamber is substantially formed by a hollow cylindrical body which is delimited on its upper end by an inhalation seat (3) onto which said sealing means press, which are formed by a sealing valve (8), and on its lower end by said additional means adapted to operate as an inhalation valve, formed by a membrane (1) .

3. The inlet connector according to the preceding claim, characterised in that said inhalation seat (3) comprises two concentric tubular elements delimiting an area crossed by the air coming from the filter, which area is subdivided into a plurality of portions by means of radial arms which extend from the outer tubular element to the inner tubular element, by means of which the latter is made integral with the former.

4. The inlet connector according to the preceding claim, characterised in that the inner tubular element of the inhalation seat (3) has an upper end which ends in a flat peripheral ring (7) which is in contact with the bottom of the mouthpiece.

5. The inlet connector according to claims 3 or 4 characterised in that the sealing valve (8) and the inhalation seat (3) are part of a moveable unit which is mounted by snap fastening onto the bottom of the mouthpiece and further comprises a leaf (2) and a disk (4), both fixed to a centrally located pin (5), at its upper and lower ends respectively, where the pin (5) runs along its own axis passing through the inner tubular element of the inhalation seat (3) acting as a guide for the pin (5) ; said leaf (2) being located outside the chamber, near its bottom, and said disk (4) being inside the chamber, and provided with a sealing valve (8) .

6. The inlet connector according to the preceding claim, characterised in that said moveable unit is controlled by a contrasting spring (6) located between the leaf (2) and the inhalation seat (3) thus achieving that when the filter is fixed onto the mouthpiece, it pushes the leaf (2) and, by overcoming the pressure of the contrast spring (6), causes the pin (5) to move downwards, moving away from the inhalation seat (3) the disk (4), which opens the sealing valve (8) and thus allowing air to enter into the chamber.

7. The inlet connector according to claim 2 and following, characterised in that the inhalation membrane (1) is mounted by means of a rivet (9) in the centre of a spider supported by a ring support (10) which is integral with the inner wall of the chamber by means of appropriate arms.

8. The inlet connector according to claim 1, characterised in that it allows the achievement of the following inhalation and exhalation resistance values,

for different air delivery capacities:

• ΔP < 0.5 mbar at 30 L/minute;

• ΔP < 1.5 mbar at 95 L/minute;

• ΔP < 4.3 mbar at 160 L/minute;

- Inhalation resistance (with filter applied to the face mask) :

• ΔP < 2.5 mbar at 30 L/minute;

• ΔP < 6.0 mbar at 95 L/minute; • ΔP < 12 . 0 mbar at 160 L/minute;

- Exhalation resistance :

ΔP < 3 . 0 mbar at 160 L/minute .