Visor-type mask for dentists

A mask to protect dentists from handpiece splatter which contains all manner of germs and viruses and has a visor which attaches to the head above the eyes and a transparent shield which extends down below the mouth. The shield is preferably detachable from the visor for cleaning and replacement. The visor has a vent for air circulation which may be closed by a cover for protection. A filter may be applied to the shield for eye protection when ultraviolet light is being used for curing plastic tooth cavity fillings.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a new and improved plastic mask for use by 
dentists, surgeons, and others who may be contaminated with germs and 
viruses of their patients and customers. The mask is supported by a band 
which fits across the forehead and around both sides of the head above the 
ears and comprises an upper or visor part which is integral with or 
attached to the band and a removable, disposable transparent shield which 
snaps onto the visor and extends substantially vertically down below the 
level of the mouth of the wearer. The shield protects the eyes, nose and 
mouth of the wearer, but does not interfere with normal breathing. The 
visor is provided with a vent which may be opened and closed as conditions 
require. Coated on or otherwise applied to the shield is a filter to 
protect the eyes from ultraviolet, blue or other harmful radiation from 
instruments which are presently used by dentists in curing tooth-filling 
plastic. 
2. Description of Related Art 
Surgical masks of gauze and paper have been used by surgeons and sometimes 
by dentists to prevent intercontamination of the doctor and patient. 
However, wearing such masks is hot and uncomfortable and, frequently, 
frightening to patients. Putting the masks on and removing them are time 
consuming and often difficult. Breath condenses within the mask and the 
latter becomes saturated with moisture and thereby fails to be an 
effective barrier to viruses and bacteria. 
Surgical masks cause the wearer to re-inhale exhaled breath causing the 
CO.sub.2 content of the blood to rise. The result of this may be increased 
heart and respiration rates and higher body temperatures and perspiration. 
Safety face shields with vents, but of different construction include U.S. 
Pat. Nos. 3,152,588; 3,298,031; 3,678,929; and 4,250,477. 
Detachable masks are shown in British Pat No. 503,750 and U.S. Pat. Nos. 
1,279,884; 2,818,829; and 3,346,875. Mere face shields are shown in U.S. 
Pat. No. 2,978,709, for example. 
Additionally, shields attached to eyeglass-type frames are shown in German 
Pat. No. 688,227; U.S. Pat. Nos. 1,582,164 and 2,774,970. 
SUMMARY OF THE INVENTION 
The present invention is in two pieces. The first piece has a band which is 
resilient and fits across the forehead and around the sides of the head 
above the ears, being sufficiently resilient so as to hold the mask in 
place. Projecting forwardly from the band is a visor which has an opening 
therein which may be closed by a cover which may be raised and lowered to 
control ventillation. 
A removable, preferably disposable transparent flexible plastic shield is 
connected to the visor by snaps or other means. The shield is curved and 
downwardly tapered to protect the eyes, nose and mouth of the wearer from 
contamination. Between uses the shield may be cleaned or, if cost 
considerations are not too great, may be discarded to prevent 
cross-contamination of patients. 
The shield protects the wearer from handpiece "splatter" and foreign 
objects such as filling and tooth structure and viruses. Burrs throw off 
saliva, tooth particles and the like. Similarly, high pressure water and 
air spread contaminants. These may enter the eye, nose and mouth of the 
dentist if not masked. 
Since the shield is detachable, it may be removed between patients or 
whenever it becomes contaminated for cleaning or replacement. 
There is provision in the mask for air circulation so that carbon dioxide 
build-up from re-breathing expelled air does not occur. Venting also 
prevents fogging the eye-glass lenses of the wearer if used. The vents are 
so located, however, that they do not defeat the anti-contamination 
features of the invention. Thus, the bottom of the shield is located 
forwardly of the mouth and nose, permitting air to flow up from below the 
face of the wearer into the space under the shield. Further, as has been 
mentioned, a vent is provided in the visor above the shield. Detritis from 
the mouth of the patient, however, cannot enter the vents because they are 
located out of a direct line of travel. If desired, a hinged or snap-in 
cover may be used to close off the vent in the visor.

The shield of the present invention is supported by means of a band 21 of a 
material such as polyethylene which is resiliently flexible. The center 
portion 22 fits around the forehead of the wearer and extends around the 
sides of the head terminating in ends 23 on either side which grip the 
head sufficiently strongly to hold the device in place without creating 
discomfort. Integral with and extending forwardly from the band 21, is a 
visor 24 shaped in the manner of a conventional sun visor. In the center 
of visor 24 is an opening 26 having a straight rear edge and a curved 
front edge which may be closed off by a cover 27. Cover 27 is connected to 
the visor 24 adjacent to front margin of the opening 26 by hinges 28. In 
the particular type of hinge illustrated herein, there is a leaf 31 fixed 
to the forward edge of cover 27, having outwardly extending hinge pins 32. 
Leaf 33 is fixed to visor 24 adjacent the opening 26 on either side of the 
device and is formed with a socket 34 into which the pin 32 snaps. By the 
pin 32 oscillating within the socket 34, the cover 27 may be raised from 
the solid line position of FIG. 2 to the dotted line position thereof. It 
will be understood that the details of construction of hinge 28 are 
subject to modification. In raised position, ventillation is achieved. 
Nevertheless, the fact that the cover 27 in open position slants 
upwardly-rearwardly prevents foreign objects from falling into the opening 
26. 
For comfort of the wearer, a resilient sponge-rubber pad 36 may be fixed to 
the inside of the band 21 to cushion contact of the latter with the skin 
of the wearer. 
Fixed in the plurality of positions (here shown as three in number) on the 
lower edge of visor 24 are bosses 28 having studs 29 projecting therefrom. 
A shield 41 (of which several varieties are illustrated and hereinafter 
described) is detachably secured to visor 24. As best shown in FIG. 8, 
shield 41 in flat condition has a preferably slightly arcuate upper edge 
42 and formed immediately below edge 42 are holes 43 spaced the same 
distance apart as the arcuate distances between studs 39. To facilitate 
the studs 39 snaping into and out of the holes 43, radial slits 44 are 
formed in the shield 41 which provide prongs which engage under the studs 
39. Thus, the shield 41 may be snapped onto the visor 24 or removed 
therefrom. Preferably the shield 41 is sufficiently inexpensive so that it 
may be discarded between uses but, if economy is a factor, the shield may 
be washed between patients. 
Although the shape of the shield 41 is subject to some modification, it 
preferably covers the eyes, nose and mouth of the user so that in 
transverse horizontal section it is approximately semicircular. Thus, the 
sides 46 of shield 41 converge, terminating in a bottom edge 47 which, in 
the form of the invention shown in FIG. 1 is at a level about the chin of 
the user. Uncontaminated air enters behind the shield 41 and any breath 
expelled from the mouth is discharged from the atmosphere rather than 
being rebreathed. This is particularly facilitated when the cover 27 is in 
open position. 
For some uses, particularly in dentistry, a filter 49 of an orange plastic 
which filters ultraviolet or high wavelength the blue light is disposed 
across the shield 41 at a level slightly below the nose. In normal use, 
the filter 49 is out of the line of sight through the shield 41. Dentists 
frequently use ultraviolet or blue light lamps (not shown) to cure plastic 
tooth-filling materials. By tilting the head upward and directing the 
eyes, the filter 49 may be interposed between the instrument emitting the 
ultraviolet light and the eyes of the wearer to protect against damage. 
Filter 49 may be of other colors, depending upon conditions under which 
the mask is used. Preferably, the outer surface of shield 41 in the region 
of band 49 is silvered to further filter undesired rays. 
As shown in FIG. 8, the filter 49a may be of a different shape than that of 
FIG. 7. Thus, there is a straight upper edge 51 extending only partially 
across the width of the shield 41a and the underside edge 52 of band 49a 
is curved upwardly. The sides 53 are rounded. The mask of FIG. 9 gives 
improved lateral vision and yet performs the necessary filtering function. 
In FIG. 9, the band 49c is located at the extreme upper end shield 41c. 
FIG. 10 shows a shield 41b having no filter incorporated therein which may 
be suitable for users who do not need the protection of a filter by reason 
of the nature of their work. 
In other respects, the shields of FIG. 8, 9 and 10 resemble the preceding 
embodiment and the same reference numerals followed by subscripts a, c and 
b, respectively, designate corresponding parts. 
Directing attention to the simplification of the invention shown in FIGS. 
11-16, the vent 26e in the visor 24d may be left open for ventillation 
purposes since the possibility of contaminating substances entering 
through the vent and contaminating the wearer of the mask is minimal. 
However, as a safety precaution, a modified cover 27d is illustrated. Such 
a cover has a forward side 56 which is curved in two planes and is 
provided with vertical ends 57 on either side. Various means may be used 
to secure the cover 57d in place. In the form shown, particularly in FIGS. 
13 and 14, a plurality of hooks 58 are fixed to the bottom edge of side 56 
and ends 57 which snap under the margins of the hole 56d. The cover 57 is 
sufficiently flexible by reason of its thin construction so that the 
fingers may be used to deform the cover 27d to snap the hooks 58 in place. 
To reinforce the visor 24d and also to provide an improved means for 
attachment of the shield 51d thereto, an arcuate ledge 61 is formed 
projecting vertically down from the underside of the visor 24d. A center 
projection 62 and end projections 63 on either side extend from the rear 
face of the ledge 61. The projections 62, 63 may be of various shapes. In 
the form of the invention shown in FIG. 15, the projections 63 on either 
side each has a vertical leg 69 and on either side of leg 69 are truncated 
round, flat projections 70. Center projection 62 is an inversion of 
projection 63. 
The shield 41d used with projections 62, 63 is formed with a center hole 66 
and end holes 67 which are complementary to the projections 62, 63 and are 
spaced apart a distance equal to the arcuate length between the 
projections 62 and 63. 
FIG. 16 shows a further modification in the use of a filter 71 which is 
detachable and re-usable. The shape of the filter 71 is subject to 
variation in that it may be similar to that of filter 49 shown in FIG. 1 
or the filters 49a, 49c or any other shape. Filter 71 may be formed in a 
thin sheet of orange plastic material or other transparent or translucent 
material which filters out the ultra violet or blue light heretofore 
mentioned. Along all or a portion of the right and left margins of the 
filter 71 are bands of pressure sensitive adhesive 72. Adhesive 72 may be 
used to attach the filter 71 in any position on shield 41d, preferably on 
the rear face thereof to avoid contaminating spray or splatter. 
The filter 71 may be applied in any position where it is most useful to the 
worker. It may be removed when the shield 41d is being cleaned and then 
replaced. Further, it will be understood that many users of the mask do 
not require a filter and, hence, a standard clear shield may be furnished 
and a supply of filters 71 provided which may be attached to perform the 
filtering function as desired. 
In other respects the structure of FIGS. 11-16 resembles that of the 
preceding modifications and the same reference numerals followed by the 
subscript d is to designate corresponding parts.