PROTECTIVE HEADGEAR EQUIPMENT WITH RESPIRATOR AND

OPTICAL SHIELD

The invention relates to a protective equipment for the head, with a breathing mask and an optical shield.

More particularly, the invention relates to protective equipment for the head comprising:

- a breathing mask that can be connected to a breathing-gas source and adapted to be applied, in a position of use, around the nose and the mouth of a user, and for supplying him/her with breathing gas,

- a eye protective shield adapted to be applied around his/her eyes, and

- first and second lock elements, respectively located on the mask and on the shield and adapted to cooperate with each other in order to secure the shield to the mask when the mask is in its position of use on the user's face.

The invention has a particularly important, though not exclusive, application in aeronautics. The mask then makes it possible to combat hypoxia or the inhalation of toxic gases. Regulations may also demand that pilots and co-pilots of transport aircraft wear equipment for protection against hypoxia permanently in certain flight conditions, and particularly at very high altitude or when a single pilot is present in the cockpit. During this period, the mask is worn without a shield. However in case of fire or in presence of smoke or irritating gases, the wearer needs to add easily and quickly a shield to protect his eyes while he keeps the mask on his face. Document U.S. Patent Application No. 2005/0210556 discloses an example of such protective equipment that is entirely satisfactory in term of protection. However, it could be advantageous to have such equipment in which the positioning of the shield on the mask as well as the unlocking of the shield from the mask, in particular when the mask is already in place on the user's face, is carried out even more simply

and more naturally.

To better address one or more concerns, in a first aspect of the invention, a head protective equipment comprises:

- a breathing mask connectable to a breathing-gas source and adapted to be applied, in a use position, around the user's nose and mouth, for supplying the user with breathing gas;

- a eye protective shield adapted to be applied around the user's eyes; and

- first and second lock elements, respectively located on the mask and on the shield, and adapted to cooperate with each other in order to secure the shield to the mask when the mask is in the use position on the user's face. The first and second elements are adapted to engage and interlock with each other to create a snap- together connection. The shield and the mask are adapted to be locked together by a two-step movement, the first step consisting in approaching the shield to the mask until the shield reaches the mask, and the second step being a substantially linear movement of bringing the shield closer to the user's nose until locking. The head protective equipment has the advantage to put in place the shield by a natural movement of the user.

In a particular embodiment, the shield comprises a grasping unit around the second lock element. The grasping unit comprises two substantially vertical surfaces and one substantially horizontal surface, the surfaces being adapted to receive the user's fingers during the positioning of the shield onto the mask. Particularly, the vertical surfaces are adapted to receive the user's thumb and middle finger and the horizontal surface is adapted to receive the user's forefinger. The embodiment has the advantage to offer a natural position of the user's fingers to grasp the shield.

In another embodiment, the mask has guidance elements to guide the shield to the locking position during the substantially linear movement. The guidance elements comprise a support area adapted to receive the shield at the end of the first step movement. They comprises also guidance

surfaces diverging from a ridge situated substantially in coincidence with the user's nose bridge, and forming two wings that are substantially symmetrical with respect to a median plane of symmetry of the user's face when the equipment is being worn by the user. The wings are substantially parallel to the linear movement. This embodiment has the advantage to guide the user in the positioning of the shield onto the mask. An other aspect of the invention is a method to lock a eye protective shield onto a breathing mask. The breathing mask is connectable to a breathing-gas source and adapted to be applied, in a use position, around an user's nose and mouth, for supplying the user with breathing gas. The eye protective shield is adapted to be applied around the user's eyes. The mask and the shield are lockable by first and second lock elements, respectively located on the mask and on the shield, and adapted to cooperate with each other in order to secure the shield to the mask when the mask is in the use position around the user's nose and mouth. The first and second elements are adapted to engage and interlock with each other to create a snap-together connection. The method comprises:

• approaching the shield to the mask until the shield reaches the mask,

• moving in a substantially linear movement the shield onto the mask to bring the shield closer to the user's nose until locking.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment described hereafter where:

- FIG. 1 is an isometric view of a protective head equipment in accordance with an embodiment of the invention; - FIG. 2 is an isometric view of a mask of the protective head equipment of FIG. 1 ;

- FIG. 3 is a lateral view of the mask and shield of the protective head equipment of FIG. 1 ;

- FIG. 4 is a sectional view along a Y-Y axis of the protective head equipment of FIG. 1 ; and

- FIG. 5 is a isometric view from the rear of the mask of the protective head equipment of FIG. 1.

In the following description, like reference numerals will be used to refer o like or corresponding elements in the different figures of the

drawings. Position terms such as "top", "bottom", etc. are used to define relative position of elements of a protective equipment when it is worn by a user.

Referring to FIG. 1 , protective equipment 1 comprises a mask 2, a harness 4 and a shield 6.

The mask 2 and the harness 4 are of a known type. They are for example of the type of those already described by the documents EP-A- 0288391 or U.S. Pat. No. 5,630,412. The mask 2 comprises a mouth-and-nose face cover 8, a demand regulator 10, a connecting unit 12 and a shell 14. The demand regulator 10 is connected to a source of pressurized breathing gas by a flexible tube 16. The connecting unit 12 connects the demand regulator 10 to the inflatable harness 4 through a harness block 17. The shell 14 covers the front of the mouth-and-nose face cover 8. The harness is fitted with straps 18 to maintain the mask 2 in use position on user's head. On each side of the mask 2, a positioning member 20 positions the harness outside the area of the user's face covered by the shield 6 in use position. In another aspect, positioning members 20 are adapted to guide the harness around the head of the user even when the harness is not inflated. Therefore, the user can put in place the mask around his/her nose and mouth by using a single hand.

As shown in FIG. 2 and FIG. 3, the mouth-and-nose face cover 8 is adapted to be applied over the bottom of a user's face. The mouth-and- nose face cover 8 comprises a cavity covering the nose and the mouth of the user. This cavity is lined with a flexible membrane also extending all around the latter in order to form a seal 22 intended to be applied in contact with the user's face. The shell 14 comprises a ridge surface 24 located substantially in coincidence with that of the user's nose when the user is wearing the mask 2. The shell 14 is substantially symmetric with respect to a median plane P corresponding to the plane of symmetry of the user's head. It comprises, on each side of the median plane P, two guidance surfaces 26, forming a groove having a funnel form starting from the

ridge surface 24. The two grooves define a translation axe XX substantially perpendicular to the ridge surface 24.

On the ridge surface 24, above the start of the guidance surfaces 26, a substantially plane surface 28 is perpendicular to the translation axe XX. The plane surface 28 comprises an opening 30 having a rectangular shape. The opening 30 is horizontally-oriented.

The shield 6 comprises a protection glass 32 and, beneath the protection glass 32, a grasping unit 34.

The grasping unit 34 comprises two substantially vertical grasping surfaces 36 and a substantially horizontal grasping unit 37. The grasping surfaces 36 have an ergonomic shape adapted to receive the user's fingers and particularly the user's thumb and middle finger for the vertical surfaces 36 and the forefinger for the horizontal surface 37.

Inside the grasping unit 34, FIG. 4 and FIG. 5, between the two grasping surfaces 36, two flexible pins 38 are attached by their proximal ends to the grasping unit 34 and form at their distal ends a hook 40 turned outwards. Each hook 40 has a substantially triangular shape.

The two pins 38 form a substantially horizontal plane.

Under the two pins 38, two convex parts 44 have a form adapted to be placed between the guidance surfaces 26 of the mask.

The operation of the head protective equipment is the following.

The user has already the mask 2 in place on his mouth and nose. The mask is kept on the user's face by the harness 4.

The user takes the shield 6 by pinching the grasping unit between the user's thumb and middle finger onto the vertical grasping surfaces 36.

The forefinger is placed onto the horizontal grasping surface 37. The finger position is natural and helps to position correctly the shield in space.

In a first movement, similar to the natural movement consisting to touch the nose with the finger, the user approaches the shield to the mask until the shield reaches the mask.

The harness block 17, the positioning members 20 as well as the part of the harness between the harness block and the positioning members act as a support element which receives the shield at the end of this

first movement.

Then, in a linear movement guided by the support element along the axis XX, the user brings the shield 6 closer to the mask 2 until the convex parts 44 arrive at the level of the guidance surfaces 26. Then, the movement is guided by the guidance surfaces 26 in which the convex parts 44 are inserted. As the guidance surfaces have a funnel- type form, the movement is increasingly guided and precise in the positioning of the shield vis-a-vis the mask. With the guided movement, the distal ends of the pins 38 arrive at the level of the opening 30. The size of the opening 30 is such that the external sides of each hook 40 slide along the side of the opening 30 and elastically move inwards the pins 38. The linear movement continues until the hooks pass through the opening 30 and the pins 38 return to their initial position. Then, the pins 38 and the opening 30 create a snap-together connection locking the shield 6 to the mask 2.

To unlock the shield 6 from the mask 2, the user holds the shield by the grasping surfaces 26, 27 as described here above and pulls the shield to break apart the mask and the shield. As the hooks 40 form an obtuse angle with the respective pins and the pins have elasticity of flexure, the pins 38 bend inwards until the hooks 40 withdraw from the sides of the opening 30. The user is then free to take away the shield 6 from the mask 2.

The man skilled in the art understands that the choice of the obtuse angle and of the elasticity of flexure of the pins has an impact on the stability of the locking mechanism, particularly on the stability of the locking position and on the needed strength to unlock the shield. The described locking mechanism has the advantage to put in place, or to take out, the shield by a natural movement of the user. While the invention has been illustrated and described in details in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiment. For instance, the guidance elements may have different forms such as, for instance, a two-teeth fork adapted to be inserted into two funnel-type

holes.