Improved strap fastening device for protective mask

Abstract

Strap fastening device for a protective mask suitable for protecting at least the respiratory tract of a user, wherein the mask (1) comprises a body (2) connected to at least one strap (3) configured to enable the user to wear the mask, the strap (3) having ends (3A, 3B), the device comprising buckles (4) relating to associated ends (3A, 3B) of the strap (3), each buckle (4) configured to interact with a limiting element (15) by means of which the buckle (4) and the end (3A, 3B) of the strap connected thereto can be connected to a connection area (10) of the mask (1), the connection area projecting from the body (2) of the mask and having opposite sides (12, 13) and a through-hole (14), one side (13) of the sides (12, 13) being suitable for a first surface (6) between a first and a second opposite surface (6,7) a body (5) of the buckle can be arranged thereon, the body (5) of the buckle has a through-hole (30) which is designed to interact with the limiting component (15), the limiting component (15) has a pin (27) which is designed to penetrate the through-holes (14, 30) of the connecting area (10) and the buckle (4), characterized in that a first and a second enlarged area (17, 28) are provided at opposite ends of the pin, both of which are tapered at one end and are designed to interact by positive locking with the connecting area (10) of the body (2) of the mask and with a seat (31; 31, 39) of the buckle, the positive locking counteracts or at least limits a rotation of the buckle (4) about an axis (X) which runs perpendicular to the connecting area (10).

Description

[0001] The present invention relates to a strap fastening device for a protective mask for the respiratory tract of a user, which is designed to cover at least a part of the user's face, according to the preamble of the main claim.

[0002] As is known, protective masks for the respiratory tract can be of the "half mask" or "full mask" type, or they can be designed to cover only part of a user's face (protecting only their respiratory tract) or the entire face (covering and protecting the eyes as well). In any case, the mask has one or more straps or bands (headgear) designed to be placed around the user's head. Each strap has a fastening device at each free end for connection to the mask, comprising a buckle designed to engage with a corresponding pin (or similar element) located on each side of the mask.This pin is normally associated with a corresponding holding area or tab that protrudes from this body.

[0003] Typically, the interaction between each buckle and its corresponding pin allows for a relative rotation between these components of the mask. This facilitates the placement of the strap on the user's head.

[0004] However, the coupling between each buckle and its corresponding pin often allows excessive rotation between the parts, even 360°; as a result, the buckle may remain oriented in a way that does not correspond to the normal orientation of the strap around the user's head. Consequently, it can be difficult to insert the end of the strap into the buckle or to adjust the length of the strap around the user's head.

[0005] In fastening devices for protective masks of the type mentioned above, it is known to limit this movement between the buckle and the pin; however, these known solutions involve buckles with a complex shape or complex coupling methods that provide fastening components which in any case allow mutual rotation between the contacting parts at an angle that may make it difficult to position and / or adjust the strap and thus the mask on the user's face.

[0006] The present invention aims to provide a protective mask of the type mentioned, which is improved compared to known masks.

[0007] In particular, the invention aims to provide a strap fastening device for a protective mask in which the rotation of the buckle around the pin, thereby connecting the corresponding end of the strap to the body of the mask, is limited at least in such a way as to keep the buckle in a position adapted to facilitate its coupling with the strap and the adjustment of the strap around the user's head.

[0008] Another task is to provide a strap fastening device for a protective mask of the aforementioned type, whereby the coupling between each buckle and the associated pin described above is achieved by structurally simple methods and at low cost.

[0009] These and other objectives, which are obvious to experts in this field, are achieved by a strap fastening device for a protective mask according to the attached claims.

[0010] For a better understanding of the present invention, the following drawings are included as a purely illustrative, but not limiting, example, in which: Fig. 1 shows a perspective view of a mask (only as an exemplary embodiment) that was manufactured according to the invention; Fig. 2 shows a perspective exploded view from the rear of an area of ​​the mask that is suitable to be connected with a strap buckle during an assembly phase; Fig. 3 a side perspective exploded view of the area of ​​the mask made of Fig. Figure 2 shows the buckle also in an exploded view during its coupling with this area of ​​the mask; Fig. 4 a front view of the mask area Fig. 2 shows during a further coupling phase with the buckle; Fig. 5 a view similar to the one in Fig. 4 is, however, with the buckle that is attached to the area of ​​the mask made of Fig. 2 is appropriate; and Fig. 6 a cross-section along line 6-6 in Fig. 5 shows.

[0011] Referring to the aforementioned figures, Fig. 1. By way of example, a full-face respirator designed to cover the entire face of a user. However, the invention also relates to a strap fastening device that can be used with any type of respirator, not just a full-face respirator like the one in Fig. 1, but also with masks of the type designed to cover only the user's respiratory tract ("half mask").

[0012] The mask, generally designated 1, comprises a body 2 to which a strap 3 of a known type is related; the strap 3 is related at each of its opposite ends 3A and 3B to an associated buckle 4, which has a body 5. In particular, the body 5 has surfaces 6 and 7 opposite each buckle 4, with the surface 6 forming a loop 9 to allow the buckle to be attached to one of the ends 3A and 3B of the strap 3. This loop 9 is of a known type to allow the length of the strap to be adjusted on the head of a user wearing the mask 1.

[0013] The buckle 4 is designed to engage with a corresponding area 10 (made of an elastomer material) of the body 2 of the mask. This area 10 (or a connection area of ​​the strap 3) projects laterally from a corresponding side 11 of the mask, to which the ends 3A and 3B of the strap 3 are to be attached. The connection area 10 has the shape of a tab and is referred to below as "tab 10".

[0014] The tab 10 has two opposing sides 12 and 13 and a standard through-hole 14. Side 13 is flat, while side 12 has a teardrop-shaped recess 18. This recess 18 and the hole 14 are designed to interact with the tab 10 (and therefore with the body 2 of the mask 1) via a connecting element 15 of the associated buckle 4.

[0015] Each connecting or limiting component 15 comprises a teardrop-shaped area or head 17 whose dimensions correspond to or are complementary to those of the teardrop-shaped recess 18 of the tab 10. As described below, the teardrop-shaped (or "cam-shaped") area or head 17 is designed to be coupled to the teardrop-shaped (or "cam-shaped") recess 18 by snapping and positive locking; that is, it is coupled to the recess 18 in such a way that its circumference 20 follows or "copies" an edge 21 of this teardrop-shaped recess 18. To achieve this, the circumference 20 and the edge 21 have essentially curved shapes, which facilitates their construction and coupling. In this way, the shape of the area 17 is complementary to the shape of the recess 18.

[0016] Consequently, with this (releasable) coupling, the teardrop-shaped area 17 cannot rotate within the teardrop-shaped recess 18, and the entire limiting component 15 is blocked with respect to the tab 10, preventing it from rotating relative to it. Furthermore, the shape of the parts (which, due to their teardrop shape, are significantly tapered at one end compared to the opposite end) facilitates the relative positioning between the area 17 and the recess 18 when the area is inserted into the recess.

[0017] From one side 26 of the head or region 17 (facing the tab 10) protrudes a pin 27 (which is smaller than the region 17), and at one of its free ends has an enlarged end region 28 (essentially circular in the example viewed from above) provided with a projecting tooth or projection 29 that tapers or has a smaller cross-section than the enlarged end region 28. Such a pin 27 and the enlarged end region 28 are designed to be forced into the hole 14; this process is facilitated by the fact that the limiting component 15 is made of a compliant material, for example, an elastomer.

[0018] The limiting component 15 therefore has a pin 27 which can be inserted into the hole 14 and at whose opposite ends the head- or teardrop-shaped area 17 or the enlarged end area 28 are provided.

[0019] Since the tab 10 is made of an elastomer material, the limiting component 15 can also be made of a rigid plastic material, whereby the insertion of the pin 27 and the enlarged end area 28 through the through hole 14 is made possible by the elasticity and deformability of the tab 10.

[0020] The enlarged end area 28 is designed to be positioned on side 13 of the tab 10.

[0021] As already explained, the buckle 4 has two opposing surfaces 6 and 7; the first surface 6 is designed to come into contact with the side 13 of the tab 10, whereas the surface 7 is designed to interact directly with the enlarged end region 28 of the limiting component 15. This interaction is achieved by inserting the end region 28 and the pin 27, which supports the pin in the hole 14 of the tab 10 and in a through hole 30 provided in the body 5 of the buckle 4 that connects the surfaces 6 and 7 of the buckle.

[0022] By inserting the pin 27 and the enlarged end area 28 into the holes 14 and 30, this end area is positioned, with the projection or protruding tooth 29 resting on the surface 7 of the buckle 4.

[0023] On this surface a seat 31 is provided for this enlarged end area 28, which has a raised edge 35 and an elongated shape with straight and parallel, opposite sides 36 and 37, which are connected to a first end of the seat 31 by a curved side 38.

[0024] In this seat, the aforementioned hole 30 opens.

[0025] The distance between sides 36 and 37 corresponds approximately to the transverse dimension (in the case of the figures, the diameter) of the enlarged end region 27, while the curved side 39 has a radius that corresponds approximately to the radius of the enlarged end region 28.

[0026] A second end of the seat 31 has a narrowed region 39, which is also bounded by the rim 35 and has a shape complementary to that of the projecting tooth 29 provided on the enlarged end region 28. The projecting tooth 29 is designed to be positioned in this narrowed region 39 when the buckle 14 is attached to the tab 10, in order to block or at least limit the relative rotation between the limiting component 15 and the buckle 14.

[0027] This is achieved during the fastening of the buckle 14 to the tab 10.

[0028] To establish this connection, the limiting component 15 is first brought into relation with the tab 10 by inserting the circular enlarged end region 28 with the projecting tooth 29 into the hole 14 of the tab 10. During this process, the head or region 17 is spatially arranged such that it is positively coupled with the teardrop-shaped recess 18 (i.e., arranged so that it fits completely into this recess and its circumference 20 rests completely against the edge of the recess 18).

[0029] Due to the specific shape of the recess 18 and the head 17 (complementary to each other), the insertion of the head 17 into this recess is unambiguous. Of course, the head and the recess can also have shapes other than those shown in the figures, but they must be similar and still identical to each other to facilitate their coupling and to prevent mutual movement between these parts when the head 17 is inserted into the recess (especially since the coupling of these latter parts, i.e., the head 17 and the recess 18, always occurs by positive locking).

[0030] After inserting the pin 27 and the enlarged end section 28 into the hole 14 of the tab 10, this section 28 is positioned on the side 13 of the tab. Due to the positive locking between the head or the teardrop-shaped section in the recess 18, the limiting component 15 is torsionally fixed to the tab 10.

[0031] At this stage, the buckle 4 is brought closer to the tab 10, with surface 6 facing the tab ( Fig. 3) The enlarged end section 28 of the limiting component 15 is then inserted into the hole 30 of the buckle, thereby bringing the enlarged end section and the projection or protruding tooth 29 into the seat 31 provided on the surface 7 of the body 5 of the buckle 4. This positioning is in Fig. 4 shown.

[0032] By acting on the buckle 4 and pulling it towards the outside of the tab 10 (i.e. moving it away from the body 2 of the mask 1), as indicated by the arrows K in Fig. As shown in Figure 4, at least the protruding tooth 29 of the enlarged end region 28 of the limiting component 15 is now brought into the narrowed part 39 of the seat 31, which is provided on the surface 7 of the body 5 of the buckle 4.

[0033] Since the narrowed part 39 of the seat 31 also has a shape that is identical or very similar to that of the projecting tooth 29, this tooth locks into the narrowed part 39 in a torsionally rigid manner (i.e., so that it cannot rotate in it).

[0034] Consequently, the buckle 4 remains locked in coupling with the tab 10 and, due to the elasticity and compliance of the material from which the limiting component 15 is made, can rotate at most by an angle α between 0° and 10° about an axis that corresponds to the longitudinal axis X of the pin 27 (and runs orthogonally to the tab 10).

[0035] In this case, it can be determined that the buckle 14 is essentially blocked with respect to the limiting component 15 (despite the possibility of the small angular rotation mentioned above).

[0036] This overcomes the problem of known solutions where the buckle can rotate 360° relative to the tab 10. Due to the device according to the invention, when connected to the tab 10 via the limiting element 15, the buckle 4 essentially maintains a fixed position relative to this tab, thus facilitating its connection to the strap 3 and the adjustment of the strap, particularly when the mask is worn.

[0037] Even in the case of the coupling of the protruding tooth 29 and the narrowed area 39 of the seat 31, this coupling between the parts is a positive fit that does not allow any relative rotation (at least not beyond a limited angular arc), while a relative displacement along a longitudinal axis M of the seat 31 (parallel to the direction of the arrows K) is allowed in order to achieve their coupling.

[0038] This further improves the locking of a buckle 4 with respect to the tab 10.

[0039] Furthermore, as in the case of the recess 18 and the head or teardrop-shaped area 17 of the boundary component 15, the shapes of the narrowed area 39 and the projecting tooth 29 can vary, as long as these shapes are identical (or substantially identical) to those of the area 39 and allow a positive-locking connection between the area 39 and the tooth 29 (i.e., a form fit between them).

[0040] A preferred embodiment of the invention has been described, and others have been specified. However, all these embodiments have the features of the invention specified in the following claims.

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