HELMET WITH AUXILIARY CIRCUIT SWITCH

Abstract: A helmet comprises a headshell (1), visor (2) and a harness (3) within which the head of the user is engagable. An auxiliary electricity supply is provided for such as a lamp or air supply operated by switch means (16) which are actuated as the helmet is engaged on or disengaged from the head of the user. Where the attachment is an air supply, the switch (16) operates a fan motor (15) which draws air into the helmet through a filter (14).

Description: This invention relates to protective helmets and, more particularly, such a helmet provided with an auxiliary electrically operated service such as a lamp or air supply. To achieve optimum usage of the auxiliary service provided on the helmet, it is important to conserve the electrical supply therefor. Operation of the auxiliary service, as may occur when manually operated switches are employed to switch the service on and off, at times when it is not strictly needed, is, therefore, to be avoided. The present invention consists in a helmet comprising a headshell, a visor mounted on the headshell, a harness suspended from the headshell and within which, during use, the head of a user is engaged, an auxiliary, electrically operated service, such as a lamp or air supply, provided on the headshell and switch means for operating said auxiliary service adapted to be actuated to switch said service into and out of operation as the helmet is respectively engaged upon and disengaged from the head of the user. The invention further consists in a respirator helmet comprising a headshell, a visor mounted on the headshell, a harness suspended within the headshell and within which, during use, the head of a user is engaged, air supply means mounted within the headshell and having a motor operated fan and a filter through which said fan enables air to be drawn into the helmet and switch means for operating said fan motor and adapted to be actuated to switch the fan motor on and off as the helmet is respectively engaged upon and disengaged from the head of a user. Suitably curtain means are provided which are hermetically attached to margins of the headshell and visor and are adapted to extend around the sides and back of the head of the user and, adjacent a free edge thereof, are provided with means for effecting engagement of said curtain means round the neck of the user. Advantageously an expiratory valve is provided on the helmet. Preferably, the expiratory valve is provided on the visor at a location below the mouth and nose of the user. Advantageously, also, power supply means for the auxiliary service are provided by rechargeable battery means located in the headshell. In one form of the invention, the switch means comprise a micro-switch mounted on the headshell and having a pivotal actuating arm which is spring biassed to extend within the harness when the helmet is not in use and is displaced to energise the auxiliary service as the head of the user is engaged in the harness. In a further form of the invention, the switch means comprise a pressure sensitive switch mounted in relation to the headshell and the harness so as to be compressed to energise the auxiliary service as the head of the user is engaged in the harness. The invention will now be described by way of example with reference to the accompanying drawings, in which: FIG. 1 is a diagrammatic side elevation of a respirator helmet according to the invention, and FIG. 2 is a diagrammatic side elevation of a modified respirator helmet according to the invention. In the drawings like reference numerals are employed to designate like parts. Although the helmets shown in Figures 1 and 2 are respirator helmets such as may be used in dust or vapour contaminated atmospheres, those skilled in the art will appreciate that the invention is applicable to helmets provided with an auxiliary electrically operated service, e.g. a lamp, other than an air supply. Referring to Figure 1, a respirator helmet comprises a headshell 1 having a visor 2 fixed relatively to the headshell and a head harness or cradle 3 suspended within the headshell which comprises a headband 4 secured by straps (not shown) to the headshell and arcuate strap members 5 by means of which the headband 4 is attached to a fixing element which 7 suspends the harness at the top thereof from the shell. Curtain means 8 are secured hermetically at marginal edges thereof to a rear edge 9 of the visor and a lower edge 10 of the headshell. Remotely from the edges 9 and 10, the curtain means at the free edge thereof are provided with a drawstring 11. The curtain means thus extend around the sides and back of the head of the wearer of the helmet, illustrated in broken outline, and the drawstring is operable to draw the free edge of the curtain means into contact with the neck of the wearer so as to inhibit the flow of noxious fumes into the helmet. At a lower end of the visor 2 is provided an expiratory valve 12 which is located below the nose and mouth of the user and allows for the passage to the ambient atmosphere of exhaled breath of the user. Air supply means 13 are provided and mounted in a part of the headshell at the rear of the user's head and comprise a filter 14 and electric motor operated fan 15 which serves to draw air into the headshell from the atmosphere by way of the filter 14. A power supply (not shown) for the motor of the fan 15 comprises a bank of rechargeable batteries which are mounted within the headshell. To energise the motor of the fan, there is provided a switch means which, in the embodiment of Figure 1, is in the form of a micro-switch 16 having a spring biassed actuating arm 17 which, when the helmet is not in use extends within the harness 3 above the headband 4. The micro-switch 16 is mounted on a rigid integral part 18 of the shell 1 located at the centre back of the head of the user. When the helmet is mounted on the head of the user, as the user's head passes into the harness through the headband 4, the arm 17 is engaged with the head of the user and swung upwardly and rearwardly. As a result of such movement, the micro-switch contacts are made and the power supply is connected to the motor of the fan which commences to draw air from the external atmosphere into the body of the helmet. The drawstring 11 is pulled to bring the free edge of the curtain means into contact with the neck of the wearer. The flow of air through the filter 14 into the helmet is controlled so as to maintain a slight positive air pressure within the body of the helmet and thereby prevent the flow into the helmet of fumes from the external atmosphere. On removal of the helmet, the drawstring 11 is slackened and the helmet is lifted from the head of the wearer. During this movement, the spring bias of the arm 17 returns the arm to its initial position thereby switching off the power supply to the fan motor. In the embodiment depicted in Figure 2, instead of a micro-switch, there is employed a pressure sensitive switch 19 which is mounted on the integral part 18 of the headshell between that part and the headband 4. Thus, when the helmet is placed on the head of the user, as the head of the user engages within the harness 3, the switch 19 is compressed so as to actuate the motor of the fan 15 and thus initiate the supply of air to the interior of the helmet. Removal of the helmet from the head of the user removes the compressive force acting on the pressure sensitive switch 19 with the result that the power supply is disconnected from the motor of the fan 15. In the embodiments of the invention described, as the auxiliary service is switched on and off as the helmet is engaged on and disengaged from the head of the wearer, the use of power is kept to a minimum so that where the power supply is in the form of rechargeable batteries, the maximum effective use of the auxiliary service per charge of the batteries is made. Also, from the safety point of view, because the switch is disposed internally of the helmet, accidental switching on or off of the power is not as likely to take place as in the case where the switch is mounted on the exterior of the helmet, thus the attendant risk of danger to the user of the helmet is minimised.

Claims: 1. A helmet comprising a headshell, a visor mounted on the headshell, a harness suspended from the headshell and within which, during use, the head of a user is engaged and an auxiliary, electrically operated service, such as a lamp or air supply, provided on the headshell, characterised by switch means within the helmet for operating said auxiliary service adapted to be actuated to switch said service into and out of operation as the helmet is respectively engaged upon and disengaged from the head of the user. 2. A respirator helmet comprising a headshell, a visor mounted on the headshell, a harness suspended within the headshell and within which, during use, the head of a user is engaged and air supply means mounted within the headshell and having a motor operated fan and a filter through which said fan enables air to be drawn into the helmet, characterised by switch means within the helmet for operating said fan motor and adapted to be actuated to switch the fan motor on and off as the helmet is respectively engaged upon and disengaged from the head of a user. 3. A helmet as claimed in Claim 2, characterised in that curtain means are provided which are hermetically attached to margins of the headshell and visor and are adapted to extend around the sides and back of the head of the user and, adjacent a free edge thereof, are provided with means for effecting engagement of said curtain means round the neck of the user. 4. A helmet as claimed in Claim 2 or Claim 3, characterised in that an expiratory valve is provided on the helmet. 5. A helmet as claimed in Claim 4, wherein the expiratory valve is provided on the visor at a location below the mouth and nose of the user. 6. A helmet as claimed in any preceding claim, characterised in that power supply means for the auxiliary service are provided by rechargeable battery means located in the headshell. 7. A helmet as claimed in any preceding claim, characterised in that the switch means comprise a micro-switch mounted on the headshell and having a pivotal actuating arm which is spring biassed to extend within the harness when the helmet is not in use and is displaced to energise the auxiliary service as the head of the user is engaged in the harness. 8. A helmet as claimed in Claim 7, characterised in that the micro-switch is mounted on an integral part of the headshell disposed at the centre back of the head of the user. 9. A helmet as claimed in any one of Claims 1 to 6, wherein the switch means comprise a pressure sensitive switch mounted in relation to the headshell and the harness so as to be compressed to energise the auxiliary service as the head of the user is engaged in the harness. 10. A helmet as claimed in Claim 9, characterised in that the switch means are disposed between the harness and an integral part of the headshell disposed at the centre back of the head of the user.

Inventors: DAMPNEY, IAN TREVOR
Applicants: HELMETS LIMITED
Application year: 1986
Main classification: A62B18
IPC codes: A62B18, A42B3