CA2072063A1

CA2072063A1 - Improvements in or relating to protective helmets

Info

Publication number: CA2072063A1
Application number: CA002072063A
Authority: CA
Inventors: Granville Collis James
Original assignee: Coal Industry Patents Ltd
Current assignee: Centurion Safety Products Ltd
Priority date: 1990-12-20
Filing date: 1992-06-23
Publication date: 1993-12-24
Also published as: ES2101729T3; DE69126112D1; GB9127008D0; SE9201996L; EP0492984A1; DE69126112T2; SE501653C2; GB2251173A; GB2251173B; EP0492984B1; AU8993591A; AU657503B2; SE9201996D0; GB9027677D0

Abstract

ABSTRACT OF THE DISCLOSURE

IMPROVEMENTS IN OR RELATING TO PROTECTIVE HELMETS

A protective helmet incorporates a visor retractable therewithin, a fan for providing filtered airflow through a duct within the shell to the visor, and ear defenders mounted substantially within the profile of the shell.

Description

- 1 2 0 72 ~ bA3 I~5PROVE~NTS IN OR ~EL~TING ~O PROTECTIVE H~3LMETS

This invention concerns improvements in or relating to protective helmets for use by operatives in indu~trial environments.

In particular, although not exclusively, the invention has reference to auch helmets for use in the mining or quarrying industrie~ wherein the need for protective headwear is e~pecially acute. Protection ia required not only to prevent physical injury but also to avoid and indeed minimise damage to the respiratory organ~, to the aural, ocular and olfactory sense~.

Protective helmets in the form of powered helmet respirator~
are already known and generally include a protective ~hell within which i5 provided means for introducing a filtered air 3upply between the wearer' 9 face and a visor which may assume a f$xed dispo~ition on the shell or may be pivotally mounted outside the #hell to allow movement into and out of an operable, ie protective, position in front of a wearer'~ face.

It is also known to provide protective heImets with ear defender~ mounted externally of the shell and pivotable between operative and inoperative position The problem is that because of their location exteriorly of the shell, they can become snagged on equipment which occa3ions discomfort to the wearer, and damage or dislodgement of the ear defender.

It has been and remain~ a feature of known powered helmet respirators that they are cumbersome and also heavy and poorly balanced when provided with respirator fans and filter, face visor and ear defenders, with conse~uential user res1stance.

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- 2 - 2 ~7~3 It is therefore an object of the present invention to provide an improved protective helmet.

According to the invention there is provided a protective helmet including a protective ahell for accommodating a wearer's head, a visor at the front part of the shell and retractable therewithin, the shell being provided with an ear defender at each side thereof, each ear defender being substantially within the profile of the shell, an air duct defined within the shell and having an inlet towards the rear part of the shell and a number of outlets associated with the front part of the shell and diracted on to the internal surface of the visor and at least some of its marginal edges which in use extend adjacent the wearer's face, a filter associated with the duct, and an air mover for introducing air to the duct.

Advantageously the air duct extends from the occipital region to terminate at the front part of the shell in the or each outlet which in use supplies air to the top part of the visox when in its operational extended position in front of a wearer' facej such that the interior of the visor is ~wept wi~h air. Preferably thar~ is provided a plurality of outlets for the air duct, the outlets being directed ~uch as in use to ~weep the interior of the vi~or with air and to target the marginal edges o~ the visor lying adjacent the wearer's face thereby to provide a pneumatic seal therearound to minimise the ingrass of injuriou~ atmospheric pollutant~.

An inner protective s~in is disposed within the shell in spaced relation thereto, the skin conveniently defining the duct between it and the internal surfa~e of the shell.
The air duct extends over a sub~tantial part of its length between the shell and the inner skin, the inner skin being bifurcated at the front part of the ahell to provide both the number of outlets and the space for visor retraction.

- 3 - ~ ~72 ~ ~'3 The shell may be formed to give at it3 rear part an outer wall and at its front part an inner wall, the front part being provided with a cover to define a channel within which the visor may retract. The cover in such an embodiment is so formed as to give the helmet a continuous or substantially continuous outer profile. The cover may for convenience be removable and replaceable, suitable fixtures being provided for that purpose.

The filter may conveniently extend across the inlet ko the duct, and the air mover may be disposed within the duct in rearwards of the crown of the shell. The air mover is constituted by at lea#t one fan, preferably hattery powered.

~he visor may be removably mounted in a carrier having a renewable transparent section constituting the visor per se. Alternatively, the carrier may comprise a frame into which a renewable transparent section may be insertabla.

The visor carrier may be slidably mounted to the interior of the shell by means oP side supports each having slot~ with which bushes on the carrier engage to afford in use and arcuate slidin~ motion for the visor into and out of an operative position in front of the wearer's face.

~ach ear defender may conveniently be provided substantially within the profile of the helmet thereby to secure that there are no protuberances which in use could constitute a source of danger by snagging.

The front part of the shell may be peaked and be provided with protective side cheeks which in use complement the vi or and the ear defender# to provide continuity arGund the wearer's face. The side cheeks form a proximity seal between the visor frame and the wearer's face, thus providing enhanced protection from side drau~ht~ of contarninated air.

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2072~63 The front part of the shell may be provided with a mount for a lamp such as is used in underground mining, the lamp being battery powered. In the one embodiment described above, the cover would be provided with the mount at the front of the helmet. The removable cover provides a degree of versatility whereby different fitments thereto can be provided on a range of covers.

By way of example only, one embodiment of protective helmet according to the invention is described below with reference to the accompanying drawings in which:

Figure 1 i8 a side view of the helmet partly in section and in position on a wearer~s head;
Figure 2 is an interior view of the helmet.
Figure 3 is a vertical section through the centre line of an ear dsfender of the helmetj and Figure 4 i~ an exploded view of the ear defender 3hown in Figure 3.
, Referring to Figures 1 and 2 of the drawings, there is shown at 1 a protective helmet in the ~orm of a powered helmet respirator in po~ition on a wearer's head 3, the re~pirator comprising a protective shell 2 having a rear part 4, a crown 6, a front part 8 and 3ides 10. A head harness (not shown) 2D is provided within the ~hell 2 for comfortabIy seating the respirator on the wearer's head 3.

An inner skin 12 extends from the rear part 4 to the front part 8 and de~ines in the occipital region an air inlet 14 acros~ which there is provided a filter 16 of suitable ~ibrous material. The filter 16 i3 clipped into a holder 13 and can thu~ be easily di3mountable and replaceable.

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A further inner skin which CompriSe# parts of the shell 4, 6, 8 extends through 4, 6 and downwards through 8 terminating in a plurality of outlets 20 in the form of ~lots. An air duct 22 is thus defined within the shell 2 between it~ inner surface and the skins 12 and 4, 6 and 8.

A front cover 9 is fixed to the shell 2 to provide a smooth profile to the helm~t exterior and with the front part of the protective shell 8, provides a space 42 into whiah the visor 30 may retract.

An air mover in the form of two battery-powered fans 24 i~
located within the duct 22 on sound-absorbing mount~ 26 rearwards of the crown 6 of the shell 2. The power for the fans 24 i~ conveniently provided by a body mounted battery pack (not shown) which is of such capacity as additionally to power a lamp (not ~hown) releasably fixable to the front part 9 on 2 bracket 29 provided for that purpose ~Figure 1).

~ visor 30 comprising a carrier 32 which is r21easably fixed to a txansparent window 34 i~ slidably and pivotally mounted on supports 38 fixed to the sides of the helmet shell 2, with bushes 39 attached to the vi~or carrier 32. The supports 38 have curved ~lots within which ~he bushe~ are adapted to ~lide.
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The visor 30 i~ retractable within a space 42 defined between part 8 of the shell 2 and the inside wall of the outer cover 9. The visor 30 ha~ a ~top for abutting a cut-off ~witch (not shown) euch that when the visor is fully extended in front of the wearer's face, the power to the fan 24 is initiated. Additionally, in this position, the visor is sealed against the inner face of the outer cover 9 by a sealing strip 21. The visor may alternatively seal again~t the outer face of the shell 8 along it~ lower edge. A

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2072~6'3 limited pivoting motion about the lower bush 39 may be provided to enable the lower part of the visor to move closer to the wearer's face, and is achieved by a small rece~s in the slot in the support 38 into which the upper bush may move.
In its operative position as shown in Figure 1, the visor 30 in conjunction with cheek plates 52 and ear defenders 60, to be described later, on the sides 10 of the shell 2 gives panoramic protection for the front and sides of the wearer's face.

The visor 30 may be provided with a range of proximity seals 5not shown) to reduce the distance between the visor margins and the wearer's face for the purpose of ~urther minimising the ingress of contaminated air into the wearer's breathing zone.

With reference to Figure 1, there i~ shown on one side of the powered helmet respirator 1 an ear de~ender 60 which is ~ecured to the shell 2. A corresponding ear defender ~not shown) is provided on the other aide o the shell. The ear defender 60 conform~ to the general profile of the helmet 1.

Re~erring now more specificall~ to Figures 3 and 4, each ear defender 60 inaludes an outer aover 101 provided to form an attachment to the helmet 1 and to contain a main body shell 102 of the defender. The main body shell 102 ia attached in spaced relation to an apertured back plate 103 enclosing 2S sound absorbing material 104 therebetween.

A cruciform spring 105 is held in po0ition within the body ~hell 102 and is engaged by a telephone activator/release knob 106 provided with a sealing face 106a for abutting a seat 114 formed around an orifice 114a extending axially through the body shell 102, the arrangement being such that when the knob 106 is depre~ed against the action of the .

'. , , ~' , 2~72~3 spring 105, the orifice 114a iB opened allowing sound to pa~
inwardly of the ear de~ender in use toward~ the ear of a helmet wearer through the apertured back plate 103. Release of pressure on the knob 106 allows the spring 105 to return the knob to a sealing position in relation to the orifice 114a thereby restoring the ear defender to it~ noise attenuating role.

An ear qeal 113 is secured to the backplate 103 in a po~ition comfortable to the wearer, and forms a contact seal with that part of the weaxer'~ head immediately surrounding the ear.

Wire-form springs 107 support the body shell 102 inside the outer cover 101 such that when the body shell 102 i~ pushed into the cover 101, the springs 107 hold the shell 102 thexein using the 'over centre' principle. When the body shell 102 is pushed in the oppo~ite direction, the spring3 107 press the ear defender seal 113 again~t the wearer's head wlth the co rect pres~ure for providing noise attenuation.
The springs 107 are attached to the outer cover 101 using vibration damper~ 108.

In u~e, in order permit the u~e of a telephone, the telephone earpiece tnot ~hown) i~ brought into contact with the knob 106 and pres~ure applied suPficiently to depress th~ ~pring 105 and thus open the orifice 114a, The outer part of the telephone earpiece is pre~sed against a seal 110 provided on the body shell 102 to exclude external noise. In this mode, sound from the telephone ear piece is transmitted via the orifice 114a, through the body shell 102 and the apertured backplate 103 to the wearer's ear. Removal of the telephone earpiece from contact with the knob 106 automatically allows the ear defender to revert to its full attenuation mode.

A reflective Rtrip 109 is wrapped around that part of the body ~hell 102 ~uch that when the ear defender i~ in it~

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207~3 non-operative (parked) position, when no sound attenuation is effected, the reflective strip i8 visible externally of the outsr cover 101. When the ear defender is in its operative position, the reflective strip 109 is not readily visible.

The outer cover 101 i8 fitted with means for a-ttachment to a helmet in one of several positions to suit the width of the wearer's head. The attachment may be effected by screws 112 or by any other suitable means.

The relatively forward part of the outer cover 101 i8 provided with a pair of tabs 115 having a serie~ of holes capable of accepting a visor atop peg 111. The peg 111 ia secured into a pair of holeY best suited to the wearer to provide a comfortable and effective position for holding the visor clo~e to, but not in contact with the wearer~ face.

In use, the helmet 1 fits snugly and comfortably on the wearer~s head 3 initially with the visor 30 in its retracted position within the space 42, the fans 24 being stationary.
Downward movement of the visor 30 brings it into its operative position as shown in ~igure 1. At the same time release of the cut-off switch ~not ahown) allows power to be restored to the fans 24 which accordingly induce an air flow through the inlet 14 and the filter 16 into the duct 22 and thence to the outlets 20 whence it travels downwards between the visor 34 and the face of the wearer to ventilate same with filtered air and to provide cooling. By virtue of the slot form of the outlets 20 and the close fitting of the visor 30 with the cheek plates 52 and ear defenders 60, a screen of air passes in a concentrated flow over the nose and mouth of the wearer, the air flow passing out between the lower margins of the visor 30 and the wearer's chin, and lower part~ o~ the cheeks.

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, . - - ., 2072~3 g The ear defender~ 60 are within the general profile o the shell 2 of the helmet 1, and present no projection likely to be a hazard. Operation of a fully integrated and custom designed helmet according to the present invention in which the ear defenders are within the profile of the shell enables noise attenuation to be achieved effectively.

The present invention thus provide~ a comprehensive and versatile powered helmet respirator possessing an optimum of protective features whilst being le~s cumbersome and less weighty than its antecedents. Equally, replacement of the filter and of the vi~or window are facilitated thus reducing cost and time spent in repair.

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Claims

1. A protective helmet including a protective shell for accommodating a wearer's head, a visor at the front part of the shell and retractable therewithin, an ear defender at each side thereof at each side of the shell, each ear defender being substantially within the profile of the shell, an air duct defined within the shell, an inlet means to the duct towards the rear part of the shell and a number of outlet means associated with the front part of the shell and directed on to the internal surface of the visor and at least some of its marginal edges which in use extend adjacent the wearer's face, a filter associated with the duct, and an air mover for introducing air to the duct.

2. A helmet according to Claim 1 in which the air duct extends from the occipital region of the helmet to terminate at the front part of the shell in each outlet means which in use is adapted to supply air to the top part of the visor when in its operational extended position in front of a wearer's face, such that the interior of the visor is swept with air.

3. A helmet according to Claim 1 in which there is provided a plurality of outlet means for the air duct, the outlet means being directed such as in use to sweep the interior of the visor with air and to target the marginal edges of the visor lying adjacent the wearer's face.

4. A helmet according to Claim 1 in which the shell provides at its rear part the outer profile of the helmet and is stepped at its front part, a removable cover being provided in spaced relation to the front part to define a space into which the visor is retractable and being continuous with the profile of the helmet.

5. A helmet according to Claim 1 in which the filter extends across the inlet means to the duct.

6. A helmet according to Claim 1 in which the air mover is disposed within the duct to the rear of the crown of the shell and downstream of the filter.

7. A helmet according to Claim 1 in which the air mover is constituted by at least one fan.

8. A helmet according to Claim 1 in which the visor includes a carrier to which a transparent section is detachably fixed.

9. A helmet according to Claim 1 in which the visor is slidably mounted to the interior of the shell by means of at least one support arm.

10. A helmet according to Claim 1 in which each ear defender is attached to the shell, the defenders having parts adapted to move between non-operating and operating positions.

11. A helmet according to Claim 10 in which the ear defender in its operating position in use contacts the otic region of a wearer.

12. A helmet according to Claim 11 in which an inner part of the ear defender is caused to contact the otic region mechanically.

13. A helmet according to Claim 11 in which the ear defenders are adapted in their operating position in contact with the otic region to prevent or allow the passage of sound therethrough.

14. A helmet according to Claim 13 in which pressure applied to the ear defenders opens sound transmission passageways therewithin thereby allowing the passage of sound.

15. A helmet according to Claim 14 in which the or each ear defender is provided with an outer cover attachable to a side of the helmet, a body shell mounted within the outer cover for movement between operational and non-operational positions, a sound transmitting means provided in the body shell, a resiliently biased means for sealing the sound transmitting means, and sound absorbing material provided within the body shell.

16. A helmet according to Claim 15 in which the mounting of the body shell within the outer cover is effected by means of wireform springs.

17. A helmet according to Claim 15 in which the resilient bias comprises a cruciform spring mounted in the body shell.

18. A helmet according to Claim 15 in which the means for sealing the sound transmitting means is an actuating knob provided with a sealing face fer abutting a seat formed around the sound transmitting means.

19. A helmet according to Claim 1 in which the front part of the shell is provided with protective side cheeks which in use complement the visor and the ear defenders to provide continuity around the wearer's face.

20. A helmet according to Claim 1 in which the front part of the helmet is provided with a mount for a lamp.

21. A helmet according to Claim 1 in which the air mover is battery-powered.