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Filters listed in this article are known to contain materials hazardous to health Exercise caution when handling and storing. Refrain from using these filters. Seek medical advice if you have any concerns. |
The Invalid Respirator, also referred to as the Invalid Helmet, was an unusually designed respirator designed for people with an illness/injury that prevented the use of a regular respirator.
Respirator Overview[]
As the name implies, this respirator was issued to invalids - people who had a severe illness or injury. Contrary to popular assumptions the Invalid respirator was not issued to those suffering from less severe respiratory issues (such as asthma). Those particular members of the public were issued the regular British General Civilian Respirator, but with a flapper valve attachment.
Frontal view - note the thick rubber-coated rope at the bottom and sides
A large pyramid-looking contraption, the Invalid Respirator cloaked the entire upper portion of the user's body. The core section of the respirator was constructed of rubber sheets which were stitched together and strengthened by thick rubber-coated rope to ensure structural integrity was plentiful and preventing the rubber hood from being too baggy.
Closeup of eye assembly, a date of 1940 is etched into the metal
Vision was afforded by two circular eyepieces made of glass. The affixation of said eyepieces to the respirator was similar to other British masks of this era - by using screw bezels. One of the metal rings on the eyepieces should be etched with a date. A manufacturers mark can also be found on these eyepieces, usually H&L.
Invalid Respirator's cowl
At the bottom of the Invalid respirator, the rubber sheeting is attached to a tan fabric neck and shoulder cowl. A thick lip made from rubber-coated rope adds more security to the attachment and helps alleviate bagginess at the bottom.
Eyelets and tightening toggle
Several fabric tabs containing metal eyelets feature on the cowl. These eyelets were to allow a piece of rope to pass through, at the end of each rope piece was a black rubber tightening toggle. When pulled and tightened, the rope caused the cowl to scrunch together, creating an airtight seal. The eyelet assembly featured on both sides; each side had its own rope tightening toggle and had to be tightened separately.
Instructions
Each Invalid respirator had a section of instructions printed on their rubber. These instructions can be viewed by lifting the filter assembly up.
Filter[]
The Invalid filter is possibly the same filter as seen on the British Baby Gas Mask. This was because the Invalid respirator began production after the war began, thus it was decided to simply use Avon's baby filter assembly, as this would create more efficiency within respirator component production.
The filter was a bellows type, in which the air was forced through the filtering layers by mechanical action, usually extending and compressing the filter with one's hand. This meant that breathing resistance was decreased significantly, as the airflow would be decided by the user's hands, not their respiratory system.
The actual filter itself is located in the upper part of the filter assembly, above the ribbed bellows section. Although it is not currently known exactly what particular filter it is, it is likely to be the same filter from the British Civilian Duty Respirator. The Baby Gas Mask used the Civilian Duty filter, so it could be suggested the Invalid Respirator followed suit. A possible explanation for such a choice is that by creating a common filter (Civilian Duty filter) between the different designs, the cost per unit could be decreased and production efficiency increased.
Fabric tape on filter assembly
The invalid respirator filter was placed inside one half of the rubber filter housing, and then connected to the rest of the filter assembly via fabric tape.
A brown fabric strap was added to the bottom of each filter assembly, to act as a hand-mount.
Closeup of filter clamp
The filter assembly was attached to the rest of the mask by a singular metal clamp that was tightened into place via a square nut and bolt. Although this example does not feature a manufacturers mark, it was possibly Longbottom & Co who made these clamps. Longbottom secured a large government contract for respirator clamps and other various fittings.
The actual filter for the invalid. Has a 'contex' pre-filter attached to the end.
For added rigidity, the filter assembly was stitched into the mask's front. Looking at the photo of the clamp assembly, one can see two circles of stitching.
Other notes[]
The Invalid Respirator is quite scarce to find today, but one can turn up once in a while from UK military and auction sites.