fig1 shows a first embodiment of the present invention . a bracing device 1 is shown fitted to a respirator mask 2 and attached to a helmet 3 . the helmet 3 has a visor 33 mounted via hinges 34 , and attachment slots 30 ( one shown ) therein . a series of straps 35 are provided for fine adjustment of the exact fit of the helmet 3 . the respirator mask 2 comprises a front module 21 , in which exhale valve 22 is formed . the mask covers the face of the user ( not shown ), to protect from dangerous environments . the mask has fitments 23 for filter modules , and a further protective visor portion 24 for protecting the eyes of the user . of course , similar bracing devices can be used with other types of mask and headgear . in the illustrated embodiment , the bracing device 1 comprises a pressure element 10 , connection portions in the form of flexible straps 11 , and helmet mounting portions 14 . note that , although only one strap 11 and helmet mounting portion 14 can be seen in fig1 , another pair is provided on the other side of the pressure element 10 . this can be seen more clearly in fig9 . the connection portions 11 are attached to the pressure element 10 at a first end 12 , and to the attachment slots 30 of the helmet 3 at a second end 13 . the illustrated connection portion 11 is divided in two pieces 110 , 111 . the first piece 110 is attached to the pressure element at a first end 12 , and the second piece 111 ( partially obscured ) is shown attached to the helmet at the second end 13 . in the illustrated embodiment , a helmet mounting portion 14 is provided at the second end 13 of the connection portion 11 , for attaching the connection portion 11 to the attachment slot 30 in the helmet . the two pieces of the connection portion 11 are joined at a buckle 112 , through which part of the first piece 110 of the connection portion 11 is threaded . the part of the first piece 110 which is threaded through the buckle 112 can be secured to the helmet mounting portion 14 . the helmet mounting portion 14 comprises flanges 130 , 131 which combine to form a channel , a slot into the channel being formed by the gap between the flanges 130 , 131 . the part of the first piece 110 which is threaded through the buckle 112 terminates with a securing tag 113 , which is sized so that it cannot be moved through the channel created by the flanges 130 , 131 on the helmet mounting portion 14 . as shown in fig8 , by feeding the part of the first piece 110 which is threaded through the buckle 112 into the slot in the channel of the helmet mounting portion 14 , the first piece 110 of the connection portion can be positioned in the channel despite the size of the securing tag 113 . the size of the securing tag 113 then prevents the first piece 110 from accidentally slipping out of the helmet mounting portion 14 , which would lead to the piece interfering with the user . when such release is desired , for example to remove the mask 2 , the user can manipulate the first piece 110 back out of the slot formed by the flanges 130 , 131 . this complex action is very unlikely to occur accidentally in normal usage . the helmet mounting portion 14 is held on the helmet 3 by a hook projection 132 , which fits into the attachment slot 30 in the helmet 3 . an example of a helmet mounting portion 13 can be seen more clearly in fig3 . in the illustrated embodiment , the pressure element 10 fits over the front module 21 of the mask 2 . to avoid any interference with the function of the mask 2 , the mask mounting portion 10 is formed with an aperture 100 therein through which the exhale valve 22 of the mask 2 protrudes . the inner surface of the pressure element 10 may be fitted with lugs 102 ( not shown ) or other contours to fit more closely to the mask 2 being used , as shown in fig9 . in the illustrated embodiment , the connection portions 11 are attached to the pressure element 10 at positions proximal the front module 21 . this arrangement provides an optimal pressure distribution to the mask 2 , pressing it onto the user &# 39 ; s face without putting pressure on the body or form of the mask 2 or the bracing device 1 . additionally , the pressure is applied mainly on the user &# 39 ; s cheeks , as opposed to their orbital bones . fig2 shows a second embodiment of the present invention . this embodiment is similar to that shown in fig1 , except in the shape of the pressure element 10 . in this embodiment , the pressure element 10 further comprises arms 101 extending to a position proximal the user &# 39 ; s orbital bone . the arms 101 engage the mask 2 , providing further distribution of pressure and evening the pressure of the user &# 39 ; s face . fig3 shows a close up of a helmet mounting portion 14 for use in the present invention . this figure more clearly shows the hook projection 132 for fixing the helmet mounting portion 14 to a suitably adapted headgear . the channel formed by the inwardly extending flanges 130 , 131 can also be seen . fig4 to 8 show a series of the steps involved in using a third embodiment of the present invention to hold a mask to a user &# 39 ; s face . the connection portions 11 of this embodiment are fitted with an elasticated expansion section 114 , which allows for a more comfortable and flexible fit to the user &# 39 ; s face . fig4 shows the bracing device 1 fitted over the front module 21 of a mask 2 , although the bracing device 1 and the mask 2 are separable . when the bracing device 1 is firmly seated on the mask 2 , for example by way of lugs 102 as shown in fig9 , the user positions the mask 2 on their face . this is shown in fig5 . the mask 2 fits onto the user as normal — with the illustrated arrangement , this means that the mask 2 fits partially under the helmet 3 . once the mask 2 is in position , each of the helmet mounting portions 14 is attached to the helmet 3 , as shown in fig6 , in the illustrated embodiment by way of fitting the hook projection 132 into the attachment slot 30 provided on the helmet 3 . at this point the mask 2 is fitted to the user and attached to the helmet 3 , but is most likely not properly tightened to give a secure protective seal . so , the connection portions 11 are reduced in length by increasing the amount of the first piece 110 which is threaded through the buckle 112 , by pulling the first pieces 110 towards the front module 10 . this action is shown in fig7 . this tightening motion reduces the effective length of the connection portions 11 , pressing the mask 2 more firmly onto the user &# 39 ; s face to provide a secure fit . additionally , because of the angle of the hook projection 132 and attachment slot 30 used to attach the headgear mounting portion 13 to the helmet 3 , this action increases the security of that attachment . after this action , the mask 2 is properly fitted to the user . however , there may be some length of the first piece 110 of the connection portion 11 left free , and this might interfere with the user &# 39 ; s actions or line of sight . so , as shown in fig8 , the excess of the first piece 110 can itself be attached to the helmet mounting portion 14 . the helmet mounting portion 14 has flanges 130 , 131 , between which the first piece 110 can be pressed . a security tag 113 at the end of the first piece 110 then holds the first piece 110 in place , as described above with reference to fig1 . fig9 shows a front view of the embodiment of fig1 . in this figure , the lugs 102 on the interior surface of the pressure element 10 can be seen . these lugs 102 help seat the bracing device 1 securely on the mask 2 ( not shown ) to be used . two connection portions 11 extend from substantially diametrically opposite sides of the pressure element 10 , to provide an even pressure to the mask 2 . in fig9 , there is again shown the excess of the first piece 110 positioned in the channel in the helmet mounting portions 14 , the securing tags 113 preventing withdrawal through the channel . fig1 shows a bracing device 1 according to a third embodiment of the present invention , partway through the process of attachment to a helmet 3 . the bracing device 1 comprises a pressure element 10 for bearing against the front module of a respirator mask ( not shown ) as described above . in this embodiment , the connection portions 120 are formed in two pieces : a first piece 121 connected to the pressure element 10 , in this embodiment by integral moulding , and a second piece 122 for attachment to the helmet 3 . the second piece comprises a helmet mounting portion 123 , which in this embodiment has a hook projection 132 as described above . the first and second pieces 121 , 122 of the connection portions 120 are coupled together so that the second piece 122 is slideable with respect to the first piece 121 , as symbolised by the arrows “ a ” in fig1 . this coupling allows the length of the connection portions 120 to be increased or decreased as necessary . such adjustment by extension or distension of the connection portions 120 allows for a close yet comfortable fit to the user . the connection portion 120 is shown partially extended in fig1 . in the illustrated embodiment , the first piece 121 and second piece 122 are elastically coupled by a spring ( not shown ). the spring biases the first and second pieces 121 , 122 together , so that to fit the bracing device 10 the second piece 122 must be “ stretched ” away from the first piece 121 to be attached to the helmet 3 via the hook projections 132 . once the second piece 122 is fitted to the helmet 3 , the biasing of the spring pulls the first piece 121 and thereby the rest of the bracing device 1 and the mask towards the user &# 39 ; s face and thus ensures a good fit of the mask . the spring allows some movement of the bracing device 1 with respect to the helmet 3 , for improved user comfort . it is contemplated that other types of elastic coupling ( for example use of an elastomer ) between the two pieces would serve a similar purpose . the spring or other elastic material which provides this biasing may be mounted in any way to give the required coupling . in some embodiments , the spring may be directly connected to the first and second pieces 121 , 122 . to reduce the chance of fouling or damage to the spring , a covered or otherwise protected or concealed spring or elastomer etc . can be used . to facilitate secure fitment of the mask , along with smooth adjustment of the fit , the first and second pieces 121 , 122 of the connection portions 120 may be coupled by a sliding mechanism . for example , the first piece 121 may comprise a channel in which a lug on the second piece 122 can run , controlling the movement of the two with respect to one another and confining movement to a particular pathway . or , two or more such channels and lugs could be provided , on either the first piece 121 or the second piece 122 . if such lugs and channels are used as the sliding mechanism , the spring or other elastic coupling of the pieces 121 , 122 may be concealed inside one of the first and second piece , further reducing the chance of damage to it . a further feature of the present invention can be seen from fig1 . as noted above , some helmets may include a protective visor 33 , which in the illustrated example can be hinged at positions 34 to swing down in front of the user &# 39 ; s face . usually , these visors are of sufficient length to completely protect the user &# 39 ; s face , and therefore the bracing device 10 is generally covered . in these situations , the exhale valve of the respirator mask being worn is very close to the visor . when the user exhales through the valve , the warmth and moisture of the exhaled air may be sufficient to cause condensation to form on the visor 33 , leading to a ‘ fogging ’. this can seriously impair visibility and the user &# 39 ; s safety . so , the pressure element 10 is adapted such that it partially obscures the exhale valve of the respirator mask ( not shown ), and ‘ funnels ’ exhaled air downwards and away from a deployed visor 33 . this can greatly reduce the fogging effect . fig1 and 12 show a preferred mode of connection between the first and second pieces 121 , 122 of the connection portions 120 . as shown in fig1 , a helical spring 1200 is connected to the first piece 121 at a point 126 , and to the second piece 122 at a point 127 . fig1 shows the connection portion 120 fully distended . in the illustrated embodiment , the two points are not aligned , leaving the spring in a diagonal / non - parallel configuration compared with the connection portions . this angling of the spring means that , when the connection portion 120 is extended in the horizontal direction , the two pieces 121 , 122 are urged together in two dimensions , corresponding to the horizontal and the vertical in fig1 . this ensures a good connection between the first and second pieces 121 , 122 . a tongue 124 formed on the second piece 122 moves in a groove 125 ( not visible in fig1 ) in the first piece 121 , keeping the first and second pieces 121 , 122 aligned . a projection 129 overhangs the end of the groove 125 , and a notch 128 in the end of the tongue 124 can fit under the projection 129 to provide a secure fit between the pieces when the spring is contracted this is shown more clearly in fig1 . of course , the features of the first and second pieces 121 , 122 could be reversed and the same principles still apply . with no channel or lug connection between the pieces , the above described connection allows maximal flexibility of the joint , helping to absorb shock . furthermore , the positioning of the spring 1200 and the tongue 124 and groove 125 connection mean that the pieces are biased into a secure fitment position . if the user dons the device quickly , slightly mis - mounting the second piece 122 to the helmet 3 , the spring 1200 can “ pull ” the piece back into its correct alignment with the first piece 121 . the first and second pieces 121 , 122 of this embodiment are shown in more detail in fig1 . the motion of the second piece 122 as controlled by the spring 125 ( not shown in fig1 ) is illustrated by the arrow marked c . the tongue 124 slides in the groove 125 , constrained by the walls thereof . as can be seen , the pieces 121 , 122 can flex with respect to one another without loss of the joint &# 39 ; s integrity . the tongue 124 and groove 125 keep the motion of the second piece 122 limited to the direction marked by the arrow c . fig1 also shows that two springs 1200 ( not shown ) can be fitted to respective points 126 on the first piece 121 to increase the stability of the joint . in fig1 , each spring is provided with a barrel - like indentation 1260 in which it can flex and move , reducing the spatial requirement of the joint . similar indentations may be provided on the underside of the second piece 122 ( not shown ). in the embodiment shown in fig1 , the bracing device 1 further comprises a support member 103 which joins the two connection portions 120 to each other . this support member is adapted to bear against the forehead of the user . when respirator masks having , for example , a visor or goggle portion are used , it is important that a good seal is achieved in the forehead region to prevent any harmful agents getting behind the visor or goggles . the support member 103 can bear against the forehead portion of such a mask to ensure the integrity of the seal . as shown in fig1 , the support member may include , for example , fitment projections 104 for keeping a good fit between the bracing device and the helmet worn by the user , or to provide a secondary attachment to the helmet . fig1 shows a bracing device 1 according to a fourth embodiment of the present invention , partway through the process of attachment to a helmet 3 . as with the third embodiment described above , the connection portions 220 are formed in two pieces : a first piece 221 connected to the pressure element 10 , and a second piece 222 for attachment to the helmet 3 . the second piece again comprises a helmet mounting portion 123 as previously described . as in the third embodiment , in this fourth embodiment the first and second pieces 221 , 222 are coupled together so that they are slideable with respect to one another . in the illustrated embodiment , the second piece 222 has the form of an arm , which is inserted through a slot 223 in the first piece 221 through which it can slide . the first piece 221 is shown with a shallow guide channel 224 cut therein to better guide the sliding path of the second piece 222 and thereby to prevent it interfering with the user . this guide path 224 also provides a smoother adjustment of the connection portion 220 , as the arm in the guide channel 224 does not suffer from , for example , additional friction from interference with other parts of the bracing device 1 . the guide channel 224 terminates in a ‘ stop piece ’ 228 which acts to stop the arm moving too far forward , or slipping out of the guide channel 224 when the arm is fully distended . again , as described above the two pieces 221 , 222 are adjustably coupled to one another . this may be as in the third embodiment , using a spring or elastomer etc ., but in the illustrated fourth embodiment a different arrangement is shown . a flexible strap 225 is attached to the first piece 221 ( in fig1 , by looping around the upper part of the slot 223 ) and runs to a buckle 226 on the second piece 222 . the illustrated fourth embodiment , as with the first and second embodiments described above , uses a “ ladder - lock ” type buckle for secure fastening . after the strap 225 has run through the buckle , it runs back , in this embodiment through the slot 223 , and preferably terminates with a tag 227 for easy gripping and adjustment of the strap 225 . the strap 225 may itself be elasticated in preferred embodiments . to don a bracing device of this fourth embodiment , the user fits the device over their mask as with other embodiments described above . the second pieces 222 of the connection portions 220 are then slid through the slots 223 , extending the strap lengths between the buckles 226 and the slots 223 , against the bias of any elastication in the straps 225 , and hooked into the helmet 3 at attachment slots 30 . when the bracing device 1 is fitted to the helmet 3 any elastication in the straps 225 pulls the two pieces 221 , 222 together to provide a close fit to the user &# 39 ; s face . if such fit is not tight enough for the user &# 39 ; s preference , or if , for example , conditions change requiring modification of the fit , the strap 225 can be pulled , by the user pulling tag 227 , through the buckle 226 , tightening the fit of the mask . this is symbolised by the arrows marked “ b ” in fig1 . in some circumstances , the user may wish to remove the fitted bracing device 1 quickly . in embodiments with straps 225 for adjusting the fit of the device 1 , where the user has altered the fit of the device 1 by tightening the straps 225 , the buckle 226 may cause difficulties to a quick loosening of the straps 225 . if the user must inch the strap 225 through one aperture of the buckle 226 , then move that slack through the other aperture , and then repeat the process until the straps 225 are loose enough for the mask to be removed , it may take an excessive time to remove the mask . furthermore , the intricate movements required for this slow process may not be easy or even possible if the user is wearing , for example , protective gloves . to overcome this problem , the “ ladder - lock ” buckle 226 of the illustrated fourth embodiment is attached by a hinge 229 to the second piece 222 of the connection portion 220 . when quick release is desired , the buckle 226 can be hinged ‘ upward ’, away from the second piece 222 of the connection portion 220 , allowing the strap 225 to follow a much less frictionally resisted path through the buckle 226 . combined with the tension under which the straps 225 will be in such situations , hinging the buckle 226 up in this way acts as a “ quick release ” for the bracing device 1 . as soon as the buckle 226 is hinged up , the tension in the strap 225 can act to pull it through its now freer path through the buckle 226 and thereby loosen the connection between the first piece 221 and second piece 222 of the connection portion 220 , allowing easier removal of the bracing device 1 from the helmet 3 . the fourth embodiment illustrated in fig1 also has a support member 103 as described above with respect to the third embodiment . the pressure element 10 is similarly adapted to that in the third embodiment , to divert air in a downward path by slight overlapping with the exhale valve . fig1 shows a bracing device 1 according to a fifth embodiment of the present invention . similarly to other embodiments previously described , the connection portions 320 are formed in two pieces : a first piece 321 connected to the pressure element 10 , and a second piece 322 for attachment to the helmet 3 ( not shown ). the second piece comprises a helmet mounting portion 123 as previously described . the fifth embodiment illustrated in fig1 also has a support member 103 as described above with respect to the third and fourth embodiments . the pressure element 10 is similarly adapted to that in the third and fourth embodiments , to divert air in a downward path by slight overlapping with the exhale valve . the first and second pieces 321 , 322 of the connection portion 320 are coupled so as to be slideable with respect to one another . the formation of the first and second pieces 321 , 322 is shown in more detail in fig1 and 16 . in this embodiment , the second piece 322 is connected to the first piece 321 by a strap 325 which is anchored in the first piece ( not shown ), and runs through a loop in the second piece 322 ( not shown ). it then runs through a path 324 in the first piece , becoming exposed at its end for the user to adjust . in fig1 , the second piece 322 is shown in contact with the first piece 321 , but elasticity in the strap 325 allows the two to be moved apart , connected only by the strap 325 . in this embodiment , the strap 325 is toothed ( not shown in fig1 ). the underside of the second piece 322 has a pawl projection corresponding to this toothing , such that the combination forms a ratchet system — this can be seen in fig1 . as the strap 325 is pulled through the path 324 in the first piece 321 , the pawl projection on the underside of the second piece 322 ratchets over the teeth on the surface of the strap 325 . this allows the strap 325 to move freely in one direction . movement in the opposite direction is prohibited by the shape of the teeth on the strap 325 and the shape of the pawl projection on the underside of the second piece 322 . of course , the two could be reversed , the pawl projection being positioned on the first piece 321 . the pawl projection on the underside of the second piece 322 is controlled by way of a simple lever 324 . when the button end of the lever 324 is pressed the pawl projection lifts from the strap 325 , allowing free movement of the strap in both directions . when the button end of the lever 324 is released , resilience in a cantilever member 326 formed to oppose the lever 324 forces the pawl projection back into contact with the strap 325 , renewing the ratchet hold thereon . fig1 shows the connection between the first piece 321 and the second piece 322 in cross sectional detail . as can be seen in this figure , the strap 325 is anchored to the first piece 321 at a point 327 . in this instance , the anchoring is achieved simply by providing a shouldering to the end of the strap 325 , which cannot fit through the anchor slot in the first piece 321 . the strap 325 then runs to the second piece 322 , looping around a mounting point 328 and proceeding through the path 324 in the first piece 321 . the pawl projection 329 can interfere with teeth ( not shown ) on the strap 325 as it passes , to provide secure ratchet fitment as described above . the lever 324 hinges around a point 330 , meaning a user can press the button end of the lever 324 to raise the pawl projection 329 . in doing so , the cantilever member 326 is forced away from the strap . when the user releases the lever 324 the cantilever member 326 returns to its original position , forcing the pawl projection 329 back onto the toothed strap 325 . the ratchet - like interaction between the strap 325 and the pawl projection 329 is shown in more detail in fig1 . it is noted that both ‘ directions ’ of ratchet are possible — the ‘ smooth ’ side of the pawl projection 329 can face either direction ( contrast fig1 and 16 ), and the teeth 331 of the strap 325 must simply face the other direction for the ratchet connection to be effective . to fit the device of the fifth embodiment , the second piece 322 can then be stretched or pulled away from the first piece 321 ( with the lever 324 depressed to relieve the ratchet connection to the strap 325 if necessary ) and fitted to the helmet ( not shown ) by way of the helmet mounting portion 123 . then , with the lever 324 released , the user can pull the strap 325 through the path 324 , ratcheting the teeth 331 past the pawl projection 329 until the mask it suitable fixed . elasticity in the strap 325 can allow for a more comfortable fit for the user , as in other embodiments described herein .
a respirator assembly has a respirator mask and a separate bracing device . the bracing device has a pressure element mountable over a frontpiece of the respirator mask , which bears against that frontpiece to hold the respirator mask against the face of a user . the bracing device also has two connection portions , each having one end attached to the pressure element and the other end being for attaching the bracing device to a helmet worn by the user . the connection portions are extendable . thus , shortening or distending the connection portions reduces the distance between the helmet and the respirator mask and thereby causes the pressure element to bear against the frontpiece of the respirator mask , compressing the user &# 39 ; s head between the helmet and the mask and thereby holding the mask against the user &# 39 ; s face .