US 2579942 A
Description (OCR text may contain errors)
Dec. 25, 1951 T, acL N 2,579,942
PROTECTIVE HOOD Fi led Nov. 18, 1948 INVENTOR 77/0/IM5 77/4/44 MAC Lt'A/V Patented Dec. 25, 1951 PROTECTIVE HQOD Thomas Traill MacLean, London, England, as-
signor to Anglo-Iranian Oil Company Limited, London, England, a British joint-stock corporation Application November 18, 1948, Serial No. 60,659 In Great Britain November 21, 1947 14 Claims. 1
The invention relates to protective hoods or helmets, such for example as those commonly used by welders and chemical workers.
The invention has among its objects to provide an improved form 0t, protective hood which can beworn without discomfort, while working for prolonged periods, and which is provided with an adequate supply of fresh air for breathing, even when the temperature of the atmosphere outside the hood is such as would normally allow the hood to be worn only for limited periods' According to the invention, a protective hood or helmet formed with a face-shield is provided with a filter immediately below the face-shield in the front of the hood or helmet and with an exit at the top or crown of the hood or helmet, whereby circulation of air within the hood or helmet is induced upwardly and over the face ofthe wearer.
According to the invention furthermore, the filter is so positioned as to be protected against the flow of liquids or other foreign bodies into the hood or helmet, except when directed upwardly and directly against the external inlet to the filter.
The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which:
Figure 1 is a. perspective view of the outside of the hood or helmet, and
Figure 2 is a cut-away perspective view on an enlarged scale of the hood or helmet.
The hood or helmet may be made of a light, rigid and durable material, and may comprise the facepiece I of curved form substantially semi-circular in transverse section to mask the face of the wearer, and the crown 2, of substantially dome-shape to form a covering for the skull of the wearer. In the facepiece l is mounted a curved panel 3 of a transparent substance such as cellulose acetate.
The two parts I and 2 are secured together along their contiguous edges by metal rivets 4 to form an air-tight joint.
The material of which the hood or helmet is made may be externally coated with an acidresisting paint.
Secured to the edges of the facepiece I and the crown 2 is a skirt or apron 5 which is adapted to complete the enclosure of the wearers head and is of such dimensions as to depend in use as far as, or beyond, the shoulders of the wearer so as to permit barring completely-or substantially the entrance of air into the helmet under the skirt. The skirt or apron 5 is secured to the facepiece and crown by means of strips 8 of a stiff reinforcing fabric material, which extends around the edges of these two parts of the hood or helmet on the inner surface, to secure the edges of the skirt between the strips 6 and the inner surfaces at the free edges of the hood or helmet. The skirt may advantaeously be made of cotton impregnated or otherwise treated with polyvinyl chloride.
A strip of reinforcing material is provided 4 around the lower edge of the crown 2 of the hood or helmet as a substantially oval frame I to follow generally the shape of a human skull, and mounted eccentrically with respect to the crown 2 to be secured at the back of the crown and leaving a space 8 of crescent shape in transverse section at the front. The front of the frame 1 is held in position in relation to the roof of the crown 2 by a curved strip 9 of the rein forcing material extending from the front rearwardly. On the outside of the frame "I is connected, in known manner, a padded strip 0 with looped tapes I I, a string or tape I2 being threaded through the loops of the tapes, whereby the hood or helmet may be adjusted to the shape of the head of the wearer so as to fit comfortably.
The lower edge of the facepiece I below the transparent panel 3 is set back towards the neck of the wearer, to form a ledge or shoulder I3 on the inside of the hood or helmet for the reception of a filter casing I4 in which may be carried any suitable adsorptive material such as activated carbon, silica gel or the like, depending upon the gases or atmosphere in which the wearer is required to work, or instead of a chemical filter, a mechanical filter may be provided.
v The underface of the ledge or shoulder I3 on the outside of the hood or helmet is provided with a series of holes I5 providing the only air inlet to the hood or helmet, thus ensuring that all air is filtered before it is passed. to the wearer.
The filter casing I4 may be formed of a plastic substance having wire gauzes I6 at top and bottom to hold the filter medium, and mounted with I of any suitable non-inflammable heat resisting transparent substance, such as cellulose acetate, and may be mounted with air-tight fit in the cut-away part of the facepiece by means of an endless strip of rubber or the like 58 forming a seating. The strip I8 is of substantially S-section to present two opposed and adjacent grooves or channels l9 and 20 respectively, in the inner of which I9 the edges of the panel 3 are received,
and the outer 2B of which engages the edges of the cut-away portion of thefac'epiece, thus err-T":
suring an air-tight joint between the facepi'ece and the panel 3, which is thus also readily'removable for replacement or repair.
The crownl2 ofthe'hood'or helmet is cut-away at"fa'-rear position to serve as an outlet?! for,
theair passing'upwardly into'the ho'od or helmet through the filter casing II. The outlet 2| is coveredby a small hood orfcasing 22 which,,inl creasingprog'r'essively in transverse cross-section is'directed rearwardly'and downwardly to follow the curve of the rear part of the crown 3 of the hood for helmet, and within the mouth of which is mounted a gauze or screen23 to prevent accidental entry of foreign bodies through the out,- letzh V r In use, air' for ventilating the inside of the i .ho'odor helmet passes upwardly through the filter casing l4 and 'from'bottom to top across the face of the wearen'and out' at the top vi'athe crescent-f shaped space 8 betw eenthe innersuriace of the c hood: or helmet 'and'the forehead of the wearer, V to "the outlet at the back of the crown 3', thus ensuring ahadequate supply of fresh filtered air forth'e' wearer, while ensuringa free passage for the air through the helmet. "The" air entering the Q hood or helmet passes closeto the inner faceof the-transparent panel thus preventing condensationof moisture on the'panel to'obstruct the view of the wearer throughlthe panel. W V The particulardispos'ition' of the filter ensures that itis protected against the entry through the air holes in the base of any liquids or-other foreignbodis, except those directed from below and directly against the holes.
I claim: a
1. A protective hood comprising incombihation a crown part a face-shield part depending from the front of said crown part and having a transparent panel-portion dimensioned to extend over substantially the full length 01 the face of the wearenwhen-the hood is in use, ahead-enclosingapron securedtofthe edges of said crown part and of said face shieldpart, and air filter means -disposed at the base of said face shield part below said panel portion and spaced-inwardly from said transparent section; saidcrown part having an outlet at a rear position thereof, whereby circu--- lation of airis induced'u-pwardly through saidair filter meansand across the face of the wearer to 65 2". :A protective hood according'to claim mom:- prising zmeans providing" an inner Supporting said-outlets '1 frame ec'centrically arranged-within said-helmet, 1
bein'g wider' than' the spate-at the-rear.
space aitthe front'betw'een'said helmet and frame over substantially. the full lengthof the faceiofa,
ated with polyvinyl chloride. ,5 5. A protective hood according to claim 1, wherein saidhelmet including said apron is exte'rnally coated with an acid-resisting paint.
"6. A protective hood comprising in combination a crown part, a face-shield part depending from thefront of said crown part and having a transparentpanel portion'j dimensioned to extend over substantially the full length of the face of the wearer when the hood is inuse, a head-enclosing apron secured flto the edges of said crown part and'of said face-shield part, and air filter means disposed atthe base of said face-shield part below said panel portion, said crown part an outlet at a rear position thereof,,, whereby circulation'of air is induced upwardly. through. said, air-,filter v means and across the; faceof thewearer torsaids. outlet, and a casing over said outlet inthe ,crown of the helmet, said casing being arranged to direct air issuing from saidoutlet, rearwardl-y and} downwardly. I V g s '7. A protective hood according to claim 6, come prising protective air screening ,means mountedw; in said casing. w i,
8. A protective hood according to claim 7,
wherein said protective air screening meansiiszag gauze. I ,7 r ,1 9 A protective hood comprising,inHcombina- ,l,. tion a grown part, place-shield part depending. from therfront of said crown-part and having a transparent: panel portion. dimensioned to extend,
thejwea'rer whenthe hood is in; use, a headre J closing apron secured to the edges f rfiaidicrowna part and, of said faceeshield;,pal fi, and air.,filter. means which is of the chemicalfilter ,type, dis-., posed at; the 7 base or said face-shield. gpartheloww saidf'panel portion, said crown part having an out let at a rear position thereof whereby, circulation? of 'air is'induce'd upwardly through said air filter means, and, across the, race of. the wearer; .to the le '2, 4 y, .11: 2.5. 10."A protective hood as defined in,c1aim; 9,, ,irr -i whichv the pl iemical filter is ,s,elected from. .the group consisting of'active carbgnand silicagel;
1 1. A protective hood lcomprising in .combina: tion a crown .par'tQaff ace-shield partdependingwih from the frontofrsaid crownfpart and ,havinga transparent panel portion'removably mounted on said face piece and dimensioned to extend, over=.:. 1
substantially the. full ,lengthloi the; faceof their. wearer when the hood is in use,.said face+-shie1d being provided with an opening for saiditranse,
channels respectively to receive the transparent panel portion of the race-shield and to,..engage. .l,i
the edge of said openingin the facei-shield, a a
head-enclosing apron secured-to the edgesiof said crown part and 'of said faceeshieldpart, and airs, filter means disposed at the base oisaid faces,
shield part below. saidpanelporticn, said crown; part having an outlet at a rear, positionithereof rli whereby circulation of airis inducedupwardly of the wearerto saidoutleth H 1 2 Aprotective hood comprisingfinrcombina through said air filter means and across .the. face.
' tion acro wn part, a jacershieldpartdepending ,1 r
, from the'front of said crown part and having a transparent panel portion dimensioned to extend over substantially the full length of the face of the wearer when the hood is in use, a head-enclosing apron secured to the edges of said crown part and of said face-shield part, a ledge portion extending inwardly of said hood below said panel portion, and air filter means including a filter casing supported by said ledge portion, said crown part having an outlet at a rear portion thereof, whereby circulation of air is induced upwardly through said air filter means and across the face of the wearer to said outlet.
13. A protective hood according to claim 12, wherein said ledge portion is provided with a series of holes forming the only air inlet to the helmet when the latter is in use.
14. A protective hood comprising in combination, a crown part, a face-shield part depending from the front of said crown part and having a transparent panel portion dimensioned to extend over substantially the full length of the face of the wearer when the hood is in use, a head-enclosing apron secured to the edges of said crown part and of said face-shield part, said face-shield and said crown part being of rigid construction REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Name Date Stern May 30, 1916 Number