AU705233B2

AU705233B2 - Face mask

Info

Publication number: AU705233B2
Application number: AU48528/96A
Authority: AU
Inventors: Staffan Ekstrom; Gunnar Innings; Ian Maxwell
Original assignee: Comasec International SA
Current assignee: Comasec International SA
Priority date: 1995-02-20
Filing date: 1996-02-19
Publication date: 1999-05-20
Anticipated expiration: 2016-02-19
Also published as: WO1996025982A1; SE9500627D0; EP0810897A1; CA2213262A1; SE504000C2; DE69608952T2; AU4852896A; JPH11500637A; SE9500627L; DE69608952D1; EP0810897B1

Description

WO 96/25982 PCT/SE96/00216 FACE MASK The present invention relates to a breathing mask which when worn is intended to cover at least the wearer's mouth and nose and which includes means to hold the mask in a fixed position on the face of a wearer, a first and a second opening, an inhalation valve fitted in the first opening and connectable to a source of breathing gas, and an exhalation valve fitted in the second opening.

Such breathing masks are known to the art. The breathing mask is normally a full-face mask which includes the described mask as an inner mask that covers the mouth and the nose region of the wearer's face, and an outer mask which is worn outside the inner mask and which covers the wearer's face and includes a transparent viewing window in the region of the wearer's eyes. The outer mask and the inner mask are normally constructed so that breathing gas from a gas-storage source will first enter the outer mask and flush the inner surface of the viewing window so as to remove any moisture that may be present, and then passes through a valve and into the inner mask. Exhalation gas leaves the mask through an exhalation valve. These valves are normally one-way valves. Such breathing masks are also usually used together with helmets which embrace the wearer's head and which include a breathing mask that covers the mouth and nose region of the wearer's face. The front side of the helmet includes a transparent viewing window or visor.

As the wearer approaches an area in which the atmosphere is known to be unsuitable or is anticipated to be unsuitable, the mask is donned and breathing gas is taken from a breathing-gas source, normally a gas cylinder having a gas pressure of up to 300 atm. Because the mask cannot be donned quickly, it must be donned in good time before entering a non-breathable atmosphere. When entering a breathable atmosphere after leaving an unbreathable atmosphere, the mask must be removed so as to not consume gas unnecessarily from the breathing-gas source, which covers only a limited breathing time.

An object of the present invention is to enable breathable ambient air to be breathed-in while wearing the mask, and to switch to breathing from the gas supply with the aid of a simple hand manipulation when the ambient air is not safe to breath.

WO 96/25982 PCT/SE96/00216 2 Another object of the invention is to provide a breathing mask of the aforesaid kind which can be switched from a gas-supply breathing mode and an ambient air breathing mode easily and effectively.

Still another object of the invention is to provide a mask which, when worn, will enable air to be inhaled through the medium of the inhalation valve, either from the gas supply or from the ambient atmosphere.

These objects are achieved in accordance with the present invention with the aid of a breathing mask which covers at least the wearer's mouth and nose and which includes means for holding the mask in a fixed position on the wearer, a first and a second opening, an inhalation valve which is fitted in the first opening and which is connectable to a source of breathing gas, and an exhalation valve fitted in the second opening. The inventive mask is characterized by a valve positioning device which is connected to the exhalation valve and which has a second position in which the exhalation valve is out of contact with the second opening, and a first position in which the exhalation valve is in contact with the second opening, wherein the wearer is only able to exhale through said opening when the device is in this latter position.

Particularly preferred embodiments have been made apparent in the claims appendant to the main claim.

The invention will now be described with reference to a non-limiting embodiment and with reference to the accompanying drawing which illustrates schematically and in horizontal section mask components disposed over the exhalation opening of a breathing mask.

The inhalation and exhalation openings of the mask are disposed in a rigid plate fitted in the mask, which is pliable and flexible in other respects. The plate is referenced 6 and the exhalation opening is referenced 1. The exhalation valve 4 solely permits the passage of gas from the opening 1 and is fitted on an arm 3. The arm 3 is pivotal about a pivot pin 2 attached to an exhalation valve positioning device in the form of a cover 5, in a manner not shown. The arm 3 has an extension 7 which extends out on the side of the pivot pin 2 distal from the exhalation valve 4.

The cover 5 is arranged for pivotal movement towards and away from the exhala- WO 96/25982 PCT/SE96/00216 3 tion valve 4. The extension 7 of the arm 3 terminates immediately adjacent the inner defining surface of the cover The cover 5 is pivotal about a pivot pin 8 between the position shown in full section lines and the position shown in dotted lines As the cover 5 is pivoted from the closed position shown in full lines to the open position 5' (shown in dotted lines), it will come into contact with the extension 7 of the arm 3 and therewith rotate the valve 4 from the position shown in full lines, in which the valve closes the opening 1, to a position 5' in which the opening 1 is open. The cover 5 is held fixed in its open and its closed position with the aid of a locking means not shown. A spring (not shown) biases the cover 5 in a direction towards its closed position.

The mask includes an indicator which indicates the position of the cover therewith obviating the need to "feel" for the cover in order to ascertain whether it is open or closed. When the mask is a full-face mask, the cover position indicator may be fitted adjacent the cover and function to cause an electric signal to be transmitted to an indication lamp provided in the viewing window or visor. This lamp may be a light emitting diode. Alternatively, the locking means may include an outwardly and upwardly projecting rod. This rod may, for instance, have an arm or some other device which extends perpendicularly to the rod axis and which must be brought from a low to a high position in order to be able to rotate the cover 5 from its opening closing position to its opening uncovering position. Similarly, the rod must be brought back to the lower position when the cover 5 is swung back to its closed position. The rod is brought to its lower position when the cover 5 is closed by means of a spring force.

When using the illustrated mask, the mask is preferably fitted with a breathing-activatable inhalation valve, preferably a valve which is controlled by the need to breath and which is connected to a portable supply of breathing gas. The connection between the gas supply and the need-controlled inhalation valve may be an open connection. The mask can be donned in good time before entering an unbreathable atmosphere. The cover 5 is therewith open and inhalation and exhalation take place through the exhalation opening 1. The need-controlled inhalation valve is not opened until activated by a subpressure, which can be generated by taking a deep breath. When expecting to enter an unbreathable WO 96/25982 PCT/SE96/00216 4 atmosphere or when detecting that an unbreathable atmosphere has been entered, the cover 5 can be closed without needing to actuate the locking means. When the cover 5 is closed, the cover will no longer act on the arm extension 7 and the valve 4 will be positioned across the exhalation opening 1 and therewith close the opening to the entry of inhalation gas.

When the cover 5, and therewith the exhalation opening 1, is closed to the supply of breathing gas, there is generated in the mask a subpressure which causes the need-controlled inhalation valve to open and gas to be breathed-in from the gas source. Air is then inhaled from the gas store and the expired gas will leave the mask through the exhalation valve 4.

The inventive mask may also be also be provided with a mechanically actuable inhalation valve, preferably a need-controlled inhalation valve, connected to a portable supply of breathing gas. The connection between the gas supply and the need-controlled inhalation valve may be an open connection. The inhalation valve is then inactive, i.e. is closed. The mask can be donned in good time before entering an unbreathable atmosphere. In this case, the cover 5 is open and gas is inhaled and exhaled through the exhalation opening 1. When expecting to enter an unbreathable atmosphere or when detecting that an unbreathable atmosphere has been entered, the cover 5 can be closed without needing to actuate the locking means. The arm extension 7 will therewith no longer act on the cover 5 and the valve 4 will be positioned across the exhalation opening 1 and therewith close the valve for inhalation purposes. As the valve is closed, the inhalation valve is activated so as to enable gas to be inhaled from the gas supply (not shown).

When the wearer re-enters a breathable atmosphere, all that is needed is to open the cover 1 and to close the normal inhalation valve. The need-controlled inhalation valve is closed automatically as the cover s opened.

The face mask according to one or more of Claims 1-12 includes preferably an outer mask or helmet fitted with a visor.

The face mask according to Claim 7 includes preferably an outer mask or a helmet with a visor provided with said indicating device.

The indicating device in the breathing mask is preferably an electronic device, for instance a light emitting diode.

Claims

1. A face mask for covering at least a wearer's mouth and nose and having means for holding the mask fixed in position on the wearer, a first and a second opening, an inhalation valve fitted in the first opening and connectable to a source of breathing gas, and an exhalation valve fitted in the second opening wherein an exhalation valve positioning device which is connected to the exhalation valve and which has a second position in which the exhalation valve is out of contact with the second opening, and a first position in which the exhalation valve is in contact with the second opening wherein solely exhalation through the opening is possible when the device is in its first position.

2. A mask as claimed in Claim 1, wherein the mask includes locking means for holding the device in said second position, in which the exhalation valve is spaced from said opening and in the first position in which the exhalation valve is in contact with said opening. *i S

3. A mask as claimed in Claim 1 or Claim 2, wherein the device is an Sa. openable cover which is attached to the outside of the mask and surrounds the exhalation valve; and in that the cover is pivotally or foldably mounted on the mask, for instance mounted on a pivot pin for pivotal movement in the plane of the cover.

4. A mask as claimed in Claim 2, wherein the device can be opened by simultaneous actuation of both the device and the locking means. a.

5. A mask as claimed in Claim 2, wherein the device can be closed solely by actuation of the device. S o• a

6. A mask as claimed in Claim 4 or Claim 5, wherein the mask includes spring means which bias the device to its first position when the locking means is actuated.

7. A mask as claimed in any one of Claims 1 to 6 including an indicating means which when the mask is worn are visible to the wearer and which indicate when the device is located in said second position in which the exhalation valve is spaced from the opening, and when the device is in its first position in which the exhalation valve is in contact with the opening.

8. A mask as claimed in Claim 7, wherein the indicating means is in mechanical or electrical contact with the locking means or with the device.

9. A mask as claimed in any of Claims 1 to 8 including a second locking means connected to the device or to the inhalation valve, said second locking means functioning to hold the inhalation valve closed when the device is in its open position. A mask as claimed in Claim 9, wherein the second locking means functions to prevent opening of the inhalation valve when the device is in its second position.

S. S S

"11. A mask as claimed in Claim 10, wherein the inhalation valve is a breathing-actuable inhalation valve which can be opened when the device is in its first position in which the exhalation valve is in contact with the opening, by virtue of the effect of a deep breath on the inhalation valve when the mask is worn.

12. A mask as claimed in Claim 10, wherein that inhalation valve is an inhalation valve that can be actuated mechanically and which is activated when the device is brought to its first position in which the exhalation valve is in contact with the opening.