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Title:
CRANIUM-COVERING EXTENSION DEVICE FOR A FACE SHIELD
Document Type and Number:
WIPO Patent Application WO/2022/115961
Kind Code:
A1
Abstract:
An extension device for a face shield features a shell of at least partially dome-like form that delimits a hollow interior space for accommodating a cranial region of a user's head. At a lower marginal area of a frontal region of the shell that is worn over the user's forehead, and at an internal surface of the shell, one or more coupling elements are arranged for selective coupling to an outer side of the face shield to secure said shell onto the face shield in a manner fully supported thereby. An internal airflow channel in a scalp-covering part of the shell communicates with a chimney-like airflow space between two forehead depressions at the frontal region to exhaust warm air from the facial region. The scalp-covering part is angled at more than 90-degrees to the lower marginal area of the frontal region, so as to reside at a rearwardly inclined slope relative to the user's head when worn for greater ventilating effect. An out-turned flange is provided on a boundary edge of the shell to enable coupling of a flexible shroud to the shell.

Inventors:
RANSON ROBERT (CA)
Application Number:
PCT/CA2021/051730
Publication Date:
June 09, 2022
Filing Date:
December 03, 2021
Export Citation:
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Assignee:
RANSON ROBERT (CA)
International Classes:
A41D13/11; A42B3/20; A61F9/04
Domestic Patent References:
WO2021195766A12021-10-07
WO2017108082A12017-06-29
Foreign References:
JP2006052497A2006-02-23
US9532617B22017-01-03
EP0492984A11992-07-01
KR20050088974A2005-09-07
US20210368883A12021-12-02
US20170112224A12017-04-27
US20170215511A12017-08-03
US20150040297A12015-02-12
Attorney, Agent or Firm:
ADE & COMPANY INC.. (CA)
Download PDF:
Claims:
22

CLAIMS:

1. An extension device for a face shield, said device comprising: a shell of predetermined self-sustaining shape and at least partially dome-like form that delimits a hollow interior space for accommodating a cranial region of a user’s head in a working position of said device when installed on said face shield in a worn position on said user’s head, said shell having a boundary edge spanning around said hollow interior space at an open side thereof through which said cranial region of the user’s head is receivable into said hollow interior space; and at a lower marginal area of a frontal region of the shell that is worn anteriorly of a forehead of the user’s head in the working position of the device, and at an internal surface of the shell that faces inwardly into said hollow interior space, one or more coupling elements arranged for selective coupling to an outer side of said face shield to secure said shell thereto in the working position.

2. The device of claim 1 consisting solely of said shell and said one or more coupling elements.

3. The device of any preceding claim wherein said coupling elements at the lower marginal area of the frontal region of the shell are the sole means by which the device is couplable to the face shield.

4. The device of any preceding claim wherein said one or more coupling elements comprise one or more pieces of fastening material attached to said internal surface of the shell.

5. The device of claim 4 wherein said one or more pieces of fastening material comprise hook or loop fastener.

6. The device of any preceding claim in combination with said face shield, wherein said face shield comprises a transparent panel for protective coverage of a facial region of said user’s head in visually unobstructive fashion, and supportive headwear attached to said transparent shield.

7. The device of claim 6 wherein the device is configured for selective coupling solely to the panel of the face shield, independently of the supportive headwear thereof.

8. The device of claim 6 or 7 wherein the panel has one or more cooperative coupling elements thereon that are of matably compatible type to the coupling elements on the shell of the device, and are laid out in matching placement thereto to align therewith in the working position of the device.

9. The device of claim 8 wherein the cooperative coupling elements comprises one or more pieces of cooperative fastening material attached to an outer side of the panel that faces away from the facial region of the user’s head in the worn position.

10. The device of claim 9 wherein the cooperative fastening material comprises loop or hook fastener.

11. The device of any one of claims 6 to 10 wherein said supportive headwear comprises padding that lines an inner side of the panel at an upper marginal area thereof that neighbours an upper boundary edge of the panel, and the panel is configured to receive selective coupling of the shell thereto also at said upper marginal area, but on an opposing outer side of the panel.

12. The device of any one of claims 6 to 11 wherein said supportive headwear comprises a flexible strap coupled directly or indirectly to the panel to span snuggly around a rear of the user’s head to support the face shield in the worn position.

13. The device of any preceding claim wherein a scalp section of the shell is joined to a top of the frontal region and spans rearward therefrom to overly a user’s scalp, and has an airflow channel on an interior side of said scalp section that runs lengthwise thereof.

14. The device of claim 13 wherein said airflow channel is neighboured on opposing sides by a pair of troughs that are recessed into an exterior of the cranial portion and have respective trough floors, relative to which a ceiling of the airflow channel is of elevated relation.

15. The device of claim 13 or 14 comprising a pair of forehead depressions residing above the lower marginal area of the frontal region, and an open airflow space left between said forehead depressions, and wherein a front end of the airflow channel fluidly communicates with said open airflow space to receive rising warm air therefrom, and channel said warm air rearwardly therefrom.

16. The device of claim 15 wherein a width of said airflow space delimited between said forehead depressions, from a widened lower end of said airflow space, tapers upwardly to a lesser width than said widened lower end.

17. The device of any one of claims 13 to 16 wherein an angle of divergence between the scalp section and the lower marginal area of the frontal region is greater than 90- degrees.

18. The device of any one of claims 1 to 12 wherein a scalp section of the shell is joined to a top of the frontal region and spans rearward therefrom to overly a user’s scalp, and an angle of divergence between the scalp section and the lower marginal area of the frontal region is greater than 90-degrees.

19. The device of claim 17 or 18 wherein the angle of divergence between the scalp section and the lower marginal area of the frontal region is at least 95-degrees.

20. The device of any one of claims 1 to 13 comprising a pair of forehead depressions residing above the lower marginal area of the frontal region, and an open airflow space left between said forehead depressions within the interior space of the shell, and wherein a width of said airflow space delimited between said forehead depressions, from a widened lower end of said airflow space, tapers upwardly to a lesser width than said widened lower end.

21. The device of any preceding claim wherein the boundary edge of the shell comprises a front segment spanning the lower marginal area of the shell, and the boundary edge comprises, at least at some areas thereof other than said front segment, has an out-turned flange thereon for use in coupling of a flexible shroud to the shell along said boundary edge.

22. The device of claim 21 further comprising at least one connector clip mated or matable with said out-turned flange to secure a flexible shroud to the shell along the boundary edge thereof.

23. The device of claim 22 wherein said connector clip is a flexible connector clip comprising an elongated extrusion with a cross-sectional profile shaped for hooked engagement onto said out-turned flange.

24. The device of claim 23 wherein said cross-sectional profile is a J-shaped profile having a stem, and an overbent hooking portion attached to an end of said stem and configured to clip onto the shell at the out-turned flange thereof in an orientation placing said stem in a position that juts into the interior space of the shell through the opening thereof, and that lines an internal perimeter-strip of the shell adjacent said opening. 25

25. The device of claim 24 wherein an outer side of said stem comprises a fastening material thereon for holding said stem to said internal perimeter-strip of the shield.

26. A method improving an effective coverage area of protective face shields, said method comprising: having an inventory of existing face shields each having a transparent panel and an associated supportive headwear by which said transparent panel is supportable in a worn position in front of a facial region of a user’s head; obtaining an inventory of supplemental extension devices for said existing face shields, each supplemental extension device comprising a shell of predetermined self-sustaining shape and dome-like form; and attaching a respective one of said supplemental extension devices to one of said existing face shields by establishing a fastened interface between an inner lower marginal area of the shell of the extension device and an outer upper marginal area of the face shield, thereby securing the face shield and the supplemental extension together in an assembled state collectively forming a combined face and head shield, of which the panel of said face shield hangs downwardly from the interior space of the shell of the supplemental extension device, and the shell of the supplemental extension device is suitably positioned to cover a cranial region of the user’s head in the worn position of the face shield.

27. The method of claim 26 wherein each supplemental extension device is a device according to any one of claims 1 to 25.

28. A protective device for shielding cranial regions of a user’s head against contaminants, said device comprising a shell made of a singular unitary piece of material of predetermined self-sustaining shape and at least partially dome-like form that delimits a hollow interior space for accommodating a cranial region of a user’s head when said protective shell is worn thereover, said shell including a frontal region for overlying a user’s forehead, and a scalp section that is joined to a top of the frontal region and spans rearwardly therefrom to overly a user’s scalp, and wherein said shell is further characterized by at least one of the following features:

(a) said front region has a pair of forehead depressions recessed into an exterior of the shell and protruding into the interior space thereof for placement against a user’ s forehead, 26 an open airflow space resides between said forehead depressions, and a width of said airflow space delimited between said forehead depressions, from a widened lower end of said airflow space, tapers upwardly to a lesser width than said widened lower end;

(b) said scalp section has an airflow channel on an interior side of said scalp section that runs lengthwise thereof;

(c) an angle of divergence between the scalp section and a lower marginal area of the frontal region is greater than 90-degrees; and

(d) a boundary edge of said shell spans around an opening through which the user’s head is accommodated entry to said interior space, and said boundary edge, at least at some areas thereof other than a front segment of the boundary edge at a frontal region of the shell, has an out-turned flange thereon for use in coupling of a flexible shroud to the shell along said boundary edge.

29. The device of claim 28 characterized by inclusion of at least feature (a).

30. The device of claim 29 also characterized by inclusion of feature (b), and wherein a front end of said airflow channel fluidly communicates with the airflow space between the forehead depressions.

31. The device of claim 28 or 29 characterized by inclusion of at least feature (b).

32. The device of claim 30 or 31 wherein said airflow channel is neighboured on opposing sides by a pair of troughs that are recessed into an exterior of the cranial portion and have respective trough floors, relative to which a ceiling of the airflow channel is of elevated relation.

33. The device of any one of claims 28 to 32 characterized by inclusion of at least feature (c).

34. The device of claim 33 wherein the angle of divergence is at least 95- degrees.

35. The device of claim 33 wherein the angle of divergence is between 95- degrees and 100-degrees, inclusive.

36. The device of any one of claims 28 to 35 characterized by inclusion of at least feature (d). 27

37. The device of claim 36 further comprising at least one connector clip mated or matable with said out-turned flange to secure a flexible shroud to the shell along the boundary edge thereof.

38. The device of claim 37 wherein said connector clip is a flexible connector clip comprising an elongated extrusion with a cross-sectional profile shaped for hooked engagement onto said out-turned flange.

39. The device of claim 38 wherein said cross-sectional profile is a J-shaped profile having a stem, and an overbent hooking portion attached to an end of said stem and configured to clip onto the shell at the out-turned flange thereof in an orientation placing said stem in a position that juts into the interior space of the shell through the opening thereof, and that lines an internal perimeter-strip of the shell adjacent said opening.

40. The device of claim 39 wherein an outer side of said stem comprises a fastening material thereon for holding said stem to said internal perimeter-strip of the shield.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 62/121,003, filed December 3, 2020, the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to personal protective equipment, and more specifically to protective face shields.

BACKGROUND

The current COVID-19 pandemic demonstrates the significant demand for adequate personal protective equipment (PPE) for medical personal who risk potential exposure to pathogens when treating infected patients. A face shield used in such context is conventionally composed of a panel of transparent polymeric material worn in curtain-like fashion hanging in front of the user’s face via attached supportive headwear, typically in the form of a headband or visor worn at forehead level. The panel is curved in a horizontal direction across the wearer’s face, so that a central region of the panel resides anteriorly of the wearer’s face over the eyes, nose and mouth, and lateral regions of the panel curve posteriorly from this central region to at least partially cover the side of the face. The shield itself typically terminates at an upper edge of the panel situated at, or shortly above, the shield’s attachment to the headband or visor, leaving at least part of the forehead and the user’ s hairline exposed, especially if a separate protective cap or other head cover is not also worn, in which case the user’s hair, scalp and crown are also open to potential exposure. Such inadequate coverage at the upper facial area (forehead) and cranial region (scalp& crown) leaves the user at risk of exposure to droplets or aerosol particles, especially those that are explosively emitted by a sneezing or coughing patient. More adequate coverage than that provided the shield itself thus conventionally requires donning of additional protective gear.

In PCT Publication No. WO2021/195766, and Registered European Community Design No. 008435192-0001, both of which are incorporated herein by reference in their entirety, Applicant has disclosed a novel face and head shield that provides more comprehensive coverage in order to protect both facial and cranial regions of the wearer’s head. However, the world’s existing inventory of PPE is dominated by face shields of conventional design. Therefore, it would be desirable if there were some way to make use of existing conventional face shields, but in a manner that does not leave the users of such existing product susceptible to the inferior protective coverage thereof.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided an extension device for a face shield, said device comprising: a polymeric shell of predetermined self-sustaining shape and at least partially dome-like form that delimits a hollow interior space for accommodating a cranial region of a user’s head in a working position of said device when installed on said face shield in a worn position on said user’s head, said polymeric shell having a boundary edge spanning around said hollow interior space at an open side thereof through which said cranial region of the user’s head is receivable into said hollow interior space; and at a lower marginal area of a frontal region of the polymeric shell that is worn anteriorly of a forehead of the user’s head in the working position of the device, and at an internal surface of the polymeric shell that faces inwardly into said hollow interior space, one or more coupling elements arranged for selective coupling to an outer side of said face shield to secure said polymeric shell thereto in the working position.

According to a second aspect of the invention, there is provided a method improving an effective coverage area of protective face shields, said method comprising: having an inventory of existing face shields each having a transparent panel and an associated supportive headwear by which said transparent panel is supportable in a worn position in front of a facial region of a user’s head; obtaining an inventory of supplemental extension devices for said existing face shields, each supplemental extension device comprising a shell of predetermined self-sustaining shape and dome-like form; and attaching a respective one of said supplemental extension devices to one of said existing face shields by establishing a fastened interface between an inner lower marginal area of the shell of the extension device and an outer upper marginal area of the face shield, thereby securing the face shield and the supplemental extension together in an assembled state collectively forming a combined face and head shield, of which the panel of said face shield hangs downwardly from the interior space of the shell of the supplemental extension device, and the shell of the supplemental extension device is suitably positioned to cover a cranial region of the user’s head in the worn position of the face shield.

According to a third aspect of the invention, there is provided a protective device for shielding cranial regions of a user’s head against contaminants, said device comprising a shell made of a singular unitary piece of material of predetermined self-sustaining shape and at least partially dome-like form that delimits a hollow interior space for accommodating a cranial region of a user’s head when said protective shell is worn thereover, said shell including a frontal region for overlying a user’s forehead, and a scalp section that is joined to a top of the frontal region and spans rearwardly therefrom to overly a user’s scalp, and wherein said shell is further characterized by at least one of the following features:

(a) said front region has a pair of forehead depressions recessed into an exterior of the shell and protruding into the interior space thereof for placement against a user’ s forehead, an open airflow space resides between said forehead depressions, and a width of said airflow space delimited between said forehead depressions, from a widened lower end of said airflow space, tapers upwardly to a lesser width than said widened lower end;

(b) said scalp section has an airflow channel on an interior side of said scalp section that runs lengthwise thereof;

(c) an angle of divergence between the scalp section and a lower marginal area of the frontal region is greater than 90-degrees; and

(d) a boundary edge of said shell spans around an opening through which the user’s head is accommodated entry to said interior space, and said boundary edge, at least at some areas thereof other than a front segment of the boundary edge at a frontal region of the shell, has an out-turned flange thereon for use in coupling of a flexible shroud to the shell along said boundary edge.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described in conjunction with the accompanying drawings in which:

Figure 1 is an exploded perspective view of a conventionally-shaped PPE face shield together with a cranial extension device according to one embodiment of the present invention, which is attachable to the face shield to supplement the protective coverage thereof by covering cranial regions of the wearer’s head.

Figure 2 is an assembled perspective view of the face shield and extension device of Figure 1.

Figure 3 is a side elevational view of the face shield and extension device of Figure 2 when worn on a user’s head.

Figure 4 is another exploded perspective view of a conventionally-shaped PPE face shield, but with a cranial extension device according to a second embodiment of the present invention.

Figure 5 is an assembled perspective view of the face shield and extension device of Figure 4.

Figure 6 is a side elevational view of the face shield and extension device of Figure 5 when worn on a user’s head.

Figure 7 is another exploded perspective view of a conventionally-shaped PPE face shield, but with a cranial extension device according to a third embodiment of the present invention.

Figure 8 is an assembled perspective view of the face shield and extension device of Figure 7.

Figure 9 is a side elevational view of the face shield of Figure 8.

Figure 10 is a rear elevational view of the face shield of Figure 8.

Figure 11 is a side elevational view of the face shield and extension device of Figure 5 when worn on a user’s head, and cross-sectioned in a bisecting medial plane denoted by line A - A of Figure 10.

Figure 14A is a rear perspective view of the shield of Figure 12E with a flexible attachment clip installed on a flanged boundary edge around a rear opening of the shield.

Figures 12A and 12B are fragmentary perspective and cross-sectional views of a flexible attachment clip for installation on a flanged boundary edge of any of the forgoing cranial extension devices.

Figures 12D and 12D show an optional variant in the profile shape of the flexible attachment clip of Figures 12A and 12B

DETAILED DESCRIPTION

Referring initially to Figure 1, and to set the context in which the present invention is intended for use, there is illustrated therein a PPE face shield 10 of conventional shape and construction. The face shield 10 thus features a curved panel 12 of transparent polymeric material so as not to obstruct the user’s vision when worn over the face for protection from droplet or aerosol carried pathogens that are emitted (e.g. coughed, sneezed, exhaled, etc.) by one or more person’s in the user’s proximity. Historically, such face shields are perhaps most often used by medical personnel to protect them from infectious or contagious pathogens from their patients, though the user of the present invention is certainly not limited to specific use in such context

The transparent panel 12 possesses a curved profile in horizontal cross-section, but has a linear profile in vertical cross-section. That is, the transparent panel 12 is curved in only one of the two dimensions of the two-dimensional polymeric sheet from which the panel 12 is formed, whereby the panel 12 is curved about a singular reference axis AR of upright orientation, and therefore has a generally arcuate profile in cross-sectional planes lying normal to that reference axis, but is not curved in cross-sectional planes parallel to that reference axis. The concave side of the panel 12 faces toward the user’s face in a worn position of the face shield 10, and is therefore referred to herein as an inner side of the panel 12. The opposing convex side of the curved panel 12 thus faces away from the user’s face, and is accordingly referred to herein as the outer side of the panel 12. An outer perimeter of the panel 12 is composed of a curved upper boundary edge 14 A, two lateral boundary edges 14B extending downward from the upper boundary edge 14A at opposing ends thereof, and a curved lower boundary edge 14C that joins together the two lateral boundary edges at bottom ends thereof in opposing relationship to the upper boundary edge 14 A.

The face shield 10 further comprises a supportive headwear 16 by which the panel 12 is supported on the user’s head. The illustrated example of face shield 10 employs a relatively thin, light-weight, low-cost, panel 12 intended for one-time disposable use, and thus also employs a supportive headwear 16 of a simple, low-cost construction that is likewise disposed of in a throw-away manner after a singular use. The illustrated headwear 16 is of a two-piece construction composed of a compressible, flexible elongated bar of foam padding 18 that braces against, and spans across, the user’s forehead in the worn position of the face shield 10. This foam padding 18 is adhered to the inner side of the panel 12 at an upper marginal area 12A thereof that is of neighbouring relation to the upper boundary edge 14A. The foam padding 18 serves multiple purposes, acting as an absorbent sponge to soak up forehead sweat of the user, while acting as a spacer between the user’s forehead and the panel 12 in order to offset the panel forwardly in spaced relation from the user’s face, and while also forming a compressively padded area of an overall headband structure that circumferentially encircles the user’s head in the worn position if the face shield. Through inclusion of such compressible padding, this headband can better conform to the user’s forehead in a secure but comfortable fashion. The remainder of the headband is embodied by flexible, preferably elastic, and optionally adjustable, strap 20. This strap 20 spans around the sides and back of the user’s head in a snugly worn position pulling the foam padding 18 firmly against the user’s forehead. The circumferentially tightened relationship of the strap 20 and foam padding 18 around the wear’s head frictionally supports the entirety of the head shield 10 thereon.

In the illustrated example, opposing ends of the strap 20 are shown as attached to the bar of foam padding 18, but it will be appreciated that they may instead be attached to directly to the panel 12 itself at or near the upper marginal area 12A thereof. In the illustrated example, the bar of foam padding 18 occupies a maximum elevation of the upper marginal area 12A of the panel 12, whereby the top of the foam padding 18 resides generally flush with the upper boundary edge 14A of the panel 12, though this need not always be the case. In some face shields, the panel 12 extends a short distance upwardly past the foam padding 18, in which the case the foam padding 18 occupies only a partial lower elevation of the upper marginal area 12A of the panel 12.

Having described the conventionally shaped and constructed face shield 10 to establish the context of the present invention, attention is now turned to the novel cranial extension device 30 also shown in the figures. The extension device 30 is selectively attachable to the conventionally shaped PPE face shield of the type described above in order to achieved a combined two-piece head and face shield that not only covers the user’s face, but also a cranial region of the user’s head. The illustrated example of the extension device 30 achieves full cranial coverage that encompasses the frontal scalp, mid-scalp and crown of the user’s head. The extension device 30 is substantially embodied by a singled-walled polymeric shell 32 of dome-like form that delimits a hollow interior space for accommodating the cranial region of the user’s head. The shell is preferably manufactured by vacuum-forming or thermo-forming of the shell over a suitably shaped male mold to impart a dome-like form of predetermined and self-sustaining shape to the shell. By self-sustaining, it is mean that the shell will normally maintain this predetermined default shape in the absence of any external force exerted on the shell.

That being said, the shell may be flexible or pliable, and thus capable of being deviated from this predetermined default shape in the presence of such external forces, even under manually applied forces of relatively low magnitude. This pliable character may be at least partially attributed to a relatively thin-walled constitution of the preferably vacuum formed or thermoformed shell, thus differentiating this non-rigid, light-weight, low-cost, one-time-use disposable shell from the significantly rigid plastics used in the production of hard hats and other impact-protective helmets, where the rigid character is key to the intended impact protection purpose of such products. Unlike such helmets, the disposable cranial extension device 30 is designed to block pathogen transmission, not to withstand forceful impact forces and reduce transmission thereof to the wearer. Accordingly, the shell 30 of the extension device 30 in each of the illustrated embodiments lacks any padded liner on its exposed interior surface, and in the illustrated example, constitutes a near entirety of the device 30, with the exception of comparably smaller coupling elements that are attached to the shell, for purposes outlined below, and span only a minor fraction of its internal surface area. In the disposable polymer shell embodiments, a thickness of the shell is preferably between 0.2 mm and 2.0 mm, and more preferably between 0.3 mm and 1.0 mm.

The hollow interior space of the shell 32 is open on only one side thereof, namely at an open bottom 32A of the shell 32, where a singular continuous boundary edge 34 spans circumferentially around the only opening into the shell’s hollow interior space. In the illustrated embodiment of Figures 1 to 3, this boundary edge 34, and the opening delimited thereby, reside solely within a singular plane P. The opening of the shell delimited by the boundary edge 34 within this plane P is greater in one of the plane’s two orthogonal dimensions than in the other. This is denoted in Figure 1 by a primary axis Ai along which the shell’s opening has a greater measurement than it does along a secondary axis A2 that lies orthogonally of the primary axis Al . The greater of these two dimensions of the shell’ s opening thus denotes a length dimension L of the shell 32, whereas the lesser of these two dimensions denotes a lesser width dimension W of the shell that’s measured orthogonally of the length. A third dimension measured orthogonally of the length L and width W dimensions denotes a height dimension H of the shell 32. Front and rear ends 32B, 32C of the shell 32 are spaced from one another in the length dimension L, while lateral sides 32D, 32E of the shell 32 are spaced from one another in the width dimension W.

In a working position of the device 10 worn over the cranial region of a user’s head, as shown in Figure 3, the front and rear ends 32B, 32C reside anteriorly and posteriorly of the user’s head, respectively, while the two lateral sides 32D, 32E reside laterally of the user’s head on opposing sides thereof. In the width dimension W, the dome-like shape of the shell 32 curves upwardly over and across the cranial region of the head between the lateral sides 32D, 32E of the shell. With reference to Figure 3, in the length direction L (i.e. in side profile), the dome-like shape of the shell 32 has a curved front section 36 that curves upwardly and posteriorly over the forehead and frontal scalp of the user’s head from near the front end 32B of the shell 32, and a curved rear section 38 that curves upwardly and anteriorly over the crown of the head from at or the rear end 32B of the shell. In the first illustrated embodiment, the dome shape of the shell 32 is a squashed or flattened-dome when viewed in side profile, as can be seen in Figure 3, where a relatively straight mid-section 40 of the shell 32 overlies the user’s scalp and joins together the curved front and rear sections 36, 38 in generally linear fashion in the length direction L. That being said, the shell may alternatively have a more continuous curvature in the length dimension L to resemble a more fully-rounded dome in its side elevation profile, like it does in its front and rear elevation profiles. The mid-section 40 may also be referred to herein as a scalp section, owing to its overlying relation to the user’s scalp in the worn state of the shell.

For the purpose of coupling together the extension device 30 and the face shield 10, the shell 32 of the extension device 30 has a set of one or more coupling elements 42 thereon a lower marginal area 44 of a frontal region of the shell. The frontal region of the shell 32 embodies a curved front segment 34A of the shell’s boundary edge 34 that spans approximately 180-degrees (i.e. the full or nearly full width of the shell) and is bisected by primary axis Ai, and this bisection point of the curved front segment 34A denotes a forwardmost apex of the shell at the front end 32B thereof. The lower marginal area 44 of the frontal region resides in immediately neighbouring elevation to the front segment 34A of the boundary edge. At this lower marginal area 44, the wall of the shell 32 stands in generally perpendicular relation to the plane P occupied by the boundary edge 34 of the shell, before the frontal region then transitions into a curved profile sloping upwardly over the frontal scalp of the user’s head in rearwardly and medially sloping fashion from the forehead and temples of the user, respectively. The curvature of the curved front segment 34A of the shell’s boundary edge 34 about upright reference axis AR, which lies normal to the plane P of the boundary edge, and a matching curvature of the lower marginal area 44 of the shell’s frontal region about this same axis, generally matches the arcuate curvature of the face shield 10 at the upper marginal area 12A of the panel 12 thereof, at least over a partial central span of these curved marginal areas 12 A, 44 of the shield 10 and extension device 12.

The coupling elements 42 reside at the interior surface of the shell 32 at the lower marginal area 44 of the shell’s frontal region, and in the illustrated example are embodied by three pieces of hook or loop fastener that are adhered to the interior surface of the shell 32 at equally spaced intervals across the frontal segment of the shell. A middle one of these three fastener pieces 42 of the illustrated embodiment is aligned at the central front end 32B of the shell. To render the otherwise conventional face shield 10 compatible with the extension device 30, cooperative coupling elements are likewise provided on the panel 12 at the upper marginal area 12A thereof, specifically at the outer side of the panel so as to reside in opposing relation to the foam padding 18 that occupies the inner side of the panel’s upper marginal area 12A. So, in the illustrated example, the panel 12 is outfitted with three pieces of loop or hook fastener 46 that are adhered to the outer side of the panel 12 at equally spaced intervals across the upper marginal area 12A thereof, with the middle piece centered widthwise across the panel 12. Accordingly, these cooperative fastener pieces 46 align with the fastener pieces 42 on the interior shell surface of the extension device 30. It will be appreciated that the number of fastener pieces used on each component may be varied, whether decreased down to as few as one piece, optionally made notably wider across the width dimension W of the shield and extension, or increased from the illustrated three-piece scenario to a greater quantity.

So, to use the extension device 30 on an existing face shield 10, a first set of hook or loop fastener pieces 42, if not preinstalled by the manufacturer, are adhered to the shell 32 of the extension device 30 on the inner surface thereof at the lower marginal area 33 of the frontal region, and a cooperative second set of loop or hook fastener pieces 46 are adhered to the panel 12 of the face shield 10 on the outer side of the upper marginal area 12A thereof. The shell 32 is slipped downwardly over the top of the face shield 10, thereby tucking the upper marginal area 12A of the face shield panel 12 up into the hollow interior space of the shell 32. The outer side of the face shield’s upper marginal area 12A and the inner surface of the shell’s lower- frontal marginal area 44 are then pressed together, thereby coupling the shield 10 and the extension 30 together via the mating of the hook and loop fastener pieces 42, 46 thereon. The assembled result is the combined face and head shield shown in Figures 2 and 3.

Referring specifically to Figure 3, when the combined shield is worn, the face shield 10 is supported in conventional fashion in front of the wearer’s face by the headwear 16 that is worn in encircling relation around the user’s head with the foam padding 18 abutting against a lower forehead region thereof. Meanwhile, the novel extension 30 is secured to the face shield 10 solely through its quick-attach hook and loop connection to the shield panel 12, without any additional or alternative connection to the headwear 16, and without requiring any separate supportive headwear of its own. The added cranial extension 30 dramatically increases the shielded PPE coverage of the user’s head, fully covering the upper forehead region, frontal scalp, mid-scalp and crown of the head in the Figure 3 example for optimal protection. Consisting solely of a thin, single-walled thermoformed or vacuum formed shell and a few pieces of hook and loop fastener, the illustrated embodiments of the extension device are extremely cost efficient, lightweight and disposable, thus representing an ideal compatibility with the described type of disposable face shield 10 on which it is used herein.

As shown in the illustrated embodiments, the shell 32 may include two inwardly protruding depressions 48 at the frontal region for bracing against the upper forehead of the wearer to help maintain the spacing of the face shield 10 from the wearer’s face. Due to their positioning at a forehead-level elevation on the shell, these depressions may be referred to herein as forehead depressions. These optional forehead depressions 48 also enable mounting of external accessories to the combined face and head shield at the floors 50 of these forehead depressions 48, as schematically shown in Figure 6 where a surgical or dental headlight 49, or other accessory (e.g. lighting or magnification device) is mountable in secured fashion atop the floor 50 of one or both forehead depression 48. In the illustrated example, securing the headlight accessory 49 is attained by co-operable mating of a first piece of hook or loop fastener material 49A that is adhered or adherable to the underside of a support base of the headlight 90, and a corresponding second piece of loop or hook fastener material 49B that is adhered or adherable on top of the depression floor 50 of the shell 32. Other fasteners, e.g. double-sided adhesive tape, may alternatively be employed for such mounting of a component to the depression floor(s) 50, provided that the bonding or coupling strength thereof is sufficient to hold the accessory 49. A singular accessory with a U-shaped or suitably shaped base may be supportable atop both depression floors 50 in embracing relation about the front of the brow ridge 54. Alternatively, two separate accessories, each mounted to the floor 50 of a respective one of the two depressions 48, may be used. Though not shown in the illustrated example, the two depression floors 50 may be interconnected by a small joining strip lying coplanar thereto and spanning across the front of the brow ridge 54, in which case the two floors 50 and joining strip cooperatively form a larger collective ledge on which one or more accessories can optionally be mounted.

As also shown in the illustrated embodiments, the scalp section 40 of shell 32 may also incorporate externally recessed troughs 52 spanning lengthwise thereof at the top of the shell toward the rear end 32C thereof from at or near the curved front section 36. As a result, the interior side of the scalp section 40 features an airflow channel 53 delimited between the troughs within the interior of the shell 32. The top ceiling of this internal, integrally formed airflow channel 53 is thus of elevated relation to the bottom floors of the two neighbouring troughs 52. A fan-fed air conduit may optionally be connected to this airflow channel 53 at the rear end 32C of the shell 32. Optional installation of a channel cover to form a floor or bottom wall of the airflow channel 53 and cooperating installation of an inlet fitting at the rear end of the airflow channel 53 to receive the fan-fed air conduit is described and illustrated in the Applicant’s incorporated PCT application cited above, particularly in Figures 11A to 11D and 13 A to 13D thereof. The connected fan is then operable to blow air through this airflow channel 53 forwardly over the cranial region of the user’s head to the forehead area, where the air continues downward into the space between the user’s face and the overlying face shield for ventilation, cooling and/or positive pressurization purposes.

In the illustrated embodiments, the shell 32 features a central brow ridge 54 that is bumped-out forwardly from the forehead depressions 48 to allow such airflow to pass downwardly between the two forehead-abutting depressions. Where a fan is not connected to the rear end of the airflow channel to blow air forwardly therethrough to the space behind the face shield (also referred to herein as the “facial region” for brevity), the airflow channel and brow ridge 54 are nonetheless useful for airflow enablement, where warm air from the facial region can rise upwardly in an internal airflow space of the brow ridge 54 that is left open between the two forehead depressions 48. The rising warm air from this airflow space of the brow ridge 54 is then channeled rearwardly by the central airflow channel 53 over the top of the user’s head, and exhausted to the ambient environment from the rear end of the airflow channel 53 at the rear end 32C of the shell 32.

However, it will be appreciated that such forehead depressions 48, and channeldefining troughs 52 are optional features that may be omitted entirely, with the shape of the extension optionally being simplified to a more purely dome-like shape. While the illustrated embodiment uses hook and loop fastener material to couple the face shield and extension together, it will be appreciated this is just one possible example of cooperatively matable coupling elements 42, 46, other examples of which may include double sided tape adhesively bonded to the shield and extension, or matable tabs or slots integrated or cut in the shield and the extension.

While the cranial extension device 30 of Figures 1 through 3 features a full-dome shell 32 that covers the entire cranial region of the user from the upper forehead to the back of the head, thus covering the entirety of the frontal scalp, mid-scalp and crown, it will be appreciated that this need not be the case, for example as evidenced by the second embodiment device 30’ shown in Figures 4 through 6. In this embodiment, the extension device 30’ is substantially the same as described above for the preceding figures, except that the shell 32 forms a partial dome that is truncated by an inclined plane Pi that slopes downwardly and forwardly from the shell’s rear end 32C, which is now situated over the crown of the user’s head (i.e. from approximately where the curved rear section 38 and straight mid-section 40 of the earlier first embodiment joined together) to around the temple area of the user, somewhere rearward of the end points of the curved front segment 34A of the boundary edge. The side profile shape of the device 30’ in the second embodiment thus lacks the curved rear section 38, and is composed only a curved front section 36 and a relatively straight scalp section 40 extending rearwardly from the top end of the curved front section 36.

In this embodiment, the entirety of the boundary edge 34, and the opening delimited thereby to receive insertion of the user’s cranial region (in this case, mainly the forehead, frontal scalp and mid-scalp, and possibly part of the crown), does not reside solely within the reference plane P that specifically contains the curved front segment 34A of the boundary edge. Instead, a front half of the boundary edge, including at least the curved front segment 34A, resides in reference plane P, while the remaining rear half 34B of the boundary edge resides in the inclined plane Pi. Here, it will be appreciated that the term “half’ is used in a general sense, meaning two parts that collectively define a whole, and not in a mathematical sense denoting exactly 50% of the whole.

Despite the truncated partial-dome shape of the shell 32, the extension device 30’ still nonetheless offers a dramatic improvement of coverage over the use of the face shield alone. In all of the illustrated embodiments, the boundary edge 34 has an out-turned flange 112 thereon, at least over the rear half of the boundary edge that spans rearwardly from the two ends of the lower marginal area 44 of the frontal region so as to likewise span rearwardly from the face shield 10 when the shell 32 is mounted in the working position thereon. This flange, for example in the manner described further below, can be used for optional connection of a flexible shroud for covering otherwise exposed areas of the user’s head that are not already covered by the face shield and connected cranial extension device, optionally in a position also draping down over the neck and shoulders of the user, in similar manner to that described in Applicant’s incorporated PCT Application cited above, and illustrated in Figure 8 thereof.

In Figure 6 of the enclosed drawings, the second embodiment also illustrates that in the working position on the worn face shield 10, the extension device’s entire structure and weight may be borne solely by its fastened connection to the face shield 10 at the overlapping marginal areas 12 A, 44 of the two components, as demonstrated by the fact that the top of the shell 32 in this illustration resides in non-contacting elevated relation to the top (scalp) of the user’s head, with the only physical head contact occurring at the forehead depressions 48. Accordingly, the supportive headwear 16 of the face shield can optionally support the entirety of the combined weight of the face shield 10 and the cranial extension device 30’, unlike visor or shield equipped helmets of various types, where the cranial covering component (helmet) is worn in weight-bearing contact atop the user’s head, with the face shield or visor having its weight borne in suspended fashion from the helmets rested position atop the user’s head. Alternatively, the cranial extension device can be worn in a seated contact atop the user’s head, specifically with the bottom walls of the recessed troughs 52 resting atop the user’s head, yet maintaining the central internal airflow channel 53 open between the troughs 52 to allow the aforementioned airflow overtop of the user’s head for improved ventilation and cooling of the facial region. The troughs 52 whose floors are of recessed elevation relative to the ceiling of the airflow channel 53 therebetween thus help assure that there is always at least some open airflow space between the user’s scalp and the overlying scalp section 40 of the shell 32, even if the lowest parts of the scalp section’s widthwise profile (the trough floors) are resting in contact with the top of the user’s head.

It will be appreciated that while the first and second illustrated embodiments of the cranial extension device 30, 30’ are shown as being transparent, this need not necessarily be the case, since it does not obstruct the user’s sight line when worn in the working position atop the face shield. Figures 7 through 11 illustrate a third embodiment of the extension device 30” that, like the second embodiment, is composed, in the non-limiting illustrated example, solely of a singular unitary shell 32 of truncated dome-like shape, and a set of one or more coupling elements 42 on the shell’s interior surface at the lower marginal area 44 of the shell’s frontal region for mating with one or more cooperative coupling elements 46 at the upper marginal area 12A of the face shield. Once again, the shell 32 may also be transparent or translucent, but is shown in opacity in Figures 7 through 11 for illustrative simplicity and convenience. The third embodiment is similar in many aspects to the second embodiment, and thus is described primarily in terms of features that distinguish it from the preceding embodiment.

The third embodiment of the device 30” once again has forehead depressions 48 and a forwardly bumped-out upright central brow ridge 54 therebetween, but the geometry of the depressions 48 and brow ridge 54 is modified somewhat for functional purpose. Particular modification is made to the relative orientation of the inner sidewalls 60 of the two forehead depressions 48, which also double as sidewalls of the upright brow ridge 54 therebetween. When the shield is worn, air can flow upwardly or downwardly over the wearer’s forehead through the inside of the brow ridge 54 between the two forehead depression 48, i.e. through the open airflow space 62 (Fig. 10) left between the inner sidewalls 60 of the two forehead depressions 48. To help with exhaust of warm air and carbon dioxide from the facial region, bottom halves 60A of the sidewalls 60 are in non-parallel tilted relation to one another in an upwardly convergent and downwardly divergent fashion. As a result, the airflow space 62 between the two forehead depressions 48 is wider at a lower end 62A thereof, whose elevation coincides with the floors 50 of the forehead depressions 48, than it is at a narrower mid-region situated further up this airflow space 62. Top halves 60B of the sidewalls 60 are also tilted relative to one another, but in opposing fashion to the lower halves, thus being upwardly divergent and downwardly convergent to one another.

From its wider bottom end 62A, the airflow space initially tapers to a narrower width to the mid-region of the airflow space 62, and then widens again toward an open, unobstructed top end 62B of the airflow space, whose elevation coincides with the top ends of the forehead depressions 48. Accordingly, the airflow space 62 is configured with a constricted mid-region between two ends of greater width than said mid-region, with the intent of providing a chimney stack or venturi like effect for more effective drawing of heated/exhaled air upwardly out of the facial region. This warm air escapes the shell through open clearance space available between the shell 32 and the top of the user’s head, which in the illustrated example is at least partially embodied by the central airflow channel 53 that is delimited between the troughs 52, and whose front end coincides with the top end 62B of the airflow space 62 of the brow ridge 54 to receive the warm upward airflow therefrom.

To also increase the volume of the available clearance space for airflow at the top of the user’s head, the third embodiment also differs from the earlier embodiments in terms of a relative angle between the lower marginal area 44 and the scalp section 40 in the side-profile shape of the shell 30, as can be seen in the side elevational view of Figure 9, and in the cross- sectional view of Figure 11, where shell 32 and attached face shield 10 have both been vertically bisected in a medial plane of symmetry. In this medial plane, denoted by line B — B of Figure 10, the lower marginal area 44 has a linear profile that hangs downward from the bottom end of the curved brow ridge 54. In this third embodiment, the angle of divergence a between the linear slopes of the lower marginal area 44 and the scalp section 40 is greater than 90-degrees, preferably at least 95-degrees, and approximately 100-degrees in one exemplary scenario. In the earlier first and second embodiments, the relative angle of divergence a between the linear slope profiles of the lower marginal area 44 and the scalp section 40 was a right angle of 90- degrees.

In the present embodiment with the greater angle of divergence a, the height of the clearance space between the top of the user’s head and the overlying scalp section 40 of the shield is greater, and gradually increases toward the back of the user’ s head owing to the inclined slope of the scalp section 40, therefore allowing plenty of clearance space for ventilation and user comfort. In the illustrated example, the scalp section 40 is linearly profiled over its entire span from the top end of the brow ridge 54 to the top end of the shell’s boundary edge 34 at the rear end 32C of the shell. In this example, the divergence angle a is therefore uniform over an entirety of the scalp section 40. Regardless of the degree of uniformity in the chosen divergence angle, at no point between the top end of the curved front section 36 and the terminal rear end 32C in the side profile of the shell in the bisecting plane of symmetry does the top of the shell ever have a convergent relationship to the marginal area 44 of the frontal region. In the illustrated example, the divergence angle a is greater than 90-degress throughout this span from the top end of the curved front section to the terminal rear end 32C of the shell.

Another differentiator in the third embodiment is an increased width of the airflow channel 53 on the interior of the scalp section 40 between the two externally recessed troughs 52. In the earlier first and second embodiments, the troughs 52 were closer to one another, resulting in a relatively narrow airflow channel 53 whose width was less than that of the airflow space 62 between the two forehead depressions 48. In the third embodiment, the troughs 52 are spaced further apart from one another to create a wider airflow channel 53 whose width spans at least a majority of the width of the internal airflow space 62 of the brow ridge 54. In the illustrated example, the front ends of the troughs 52 intersect the top ends of the forehead depressions 48, and the front end of the airflow channel 53 spans the entire width of the top end of the brow ridge airflow space 62. The airflow channel maintains at least this much width over its entire rearward span to the top rear end 32C of the shell. Between the stack effect working on the warm air in the facial region, the optimized venturi-like shape of the brow ridge airflow space 62 and the wide airflow channel 53 that fluidly communicates therewith, effective exhausting of the warm air from the facial region may be achieved, even in fully passive implementations lacking a powered ventilation fan.

In the third embodiment, the forward reach of each trough 52 in the scalp section 40 is sufficient to reach to the respective forehead depression 48 on the same side of the medial plane, whereby the front end of the airflow channel 53 between the two depressions 48 fully joins up with the top end 62B of the internal airflow space 62 of the brow ridge 54. On the other hand, the troughs 52 of the third embodiment have less of a rearward span that the earlier embodiments, and thus terminate short of the top rear end 32C of shell 32. In the third embodiment, the forehead depressions 48 are shallower than those of the earlier embodiments, whereby the floors 50 of these depressions may lack sufficient depth for securement of accessories thereto, but a brow ridge recess 64 is provided in an exterior of the brow ridge 54, and in the illustrated example spans fully thereacross from one forehead depression 48 to the other at the narrow mid-region of the internal airflow space 62, and may be useful in securement of optional accessories (lighting, camera and/or magnification devices) to the shell 32, for which the exterior troughs 52 of the scalp section 40 may also be useful in housing and/or securing of such accessories in positions residing at least partially atop the shell 32.

As mentioned in relation to the earlier embodiments, the boundary edge 34 of the shell has an out-turned flange 112 thereon, by which a flexible shroud can be attached to the shell 32. For such purpose, Figures 12A through 12D illustrate a flexible attachment clip 114 having an extruded profile that is generally J-shaped in profile, and can be used on the out-turned flanges of any of the various disclosed embodiments of the extension device. This J-shaped profile includes a lower overbent hooking portion 116 denoting the curved bottom end of the J- shape, and a stem 118 standing upright from the hooking portion 116 to the define the top end of the J-shape. An originating bottom span 116A of the overbent hooking portions 116 juts outwardly to one side of the stem 118 from a bottom base end thereof. A returning top span 116A, thus reaching back toward the stem 118. The returning top span 116 stops short of the stem 118 so as to leave a small gap space 120 between the stem 118 at a terminal end 116C of the returning top span 116B. Figures 12A and 12B illustrate one version of the J-shaped profile, where after the 180-degree curve at the hooking portion’s distal bend 116D furthest from the stem 118, the remainder of the returning portion 116B is generally linear in its reach back toward the stem, and lies generally parallel to the similarly linear originating bottom span 116A. Figures 12C and 12D illustrate an alternate variant of the J-shaped profile, where the returning upper span 116B is curved throughout, and thus curves downwardly toward the originating bottom span 116A during its inward return toward the stem 118, rather than running parallel to the originating bottom span 116A.

The overbent hooking portion 116 is resiliently flexible, which allows the returning upper span 116B to be temporarily flexed away from the originating lower span 116A such that the out-turned flange 112 of the shell 32 can be inserted between the two spans 116A, 116B of the overbent hooking portion 116 via the small gap 120 left between the stem 118 and the terminal end 116C of the overbent hooking portion 116. The returning upper span 116B will snap back into its default position closely adjacent the originating bottom span 116A, thus biasing itself against the front side of the shell’s out-turned flange 112, thereby holding the flexible connector clip 114 on the shell 32 of the extension device.

In this installed position of the connector clip 114 on the boundary edge 112 of the shell 32, the stem 118 of the connector clip’s J-shaped profile reaches into the interior space of the shell 32, and lines the interior surface of the shell along a perimeter strip thereof around the shell’s opening, in the same manner shown for a combined head and face shield in Figure 14A of Applicant’s incorporated PCT application cited above. In the present invention however, the connector clip 114 only occupies the rear segment 34B of the boundary edge 34, and the not the front portion 34A thereof at the lower marginal area 44 occupied by the separate face shield. In view of this, the out-turned flange 112 may be included on only the rear segment 34B of the shell’s boundary edge. In the illustrated embodiments with the airflow channel 53, two connector clips 114 may be used, each occupying a respective half of the boundary edge’s rear segment 34B, from the rear end of the airflow channel at the rear end 32C of the shell to a respective nearest end of the lower marginal area 44 of the shell. In the second and third illustrated embodiments, it be seen that the out-turned flange 112 may protrude further outward from the opening of the shell 32 at areas immediately neighbouring the airflow channel 53 on either side thereof. In the illustrated example, the protruding depth of the flange 112 increases gradually over these channel-neighbouring areas in a centrally inward direction toward the airflow channel 54. As a result, this variable-depth section of the flange 112A forms a triangular gusset that serves to reinforce the shape of the airflow channel 53 at the rear end thereof. In such embodiments, each connector clip is installed in a position spanning from the triangular gusset 112A on one side of the airflow channel 53 to the nearest end of the shell’s lower marginal area 44. Each flexible connector clip 114, for example composed of a flexible polymeric material, is flexible in its elongated extrusion direction, allowing it to conform to the interior contours of the shell 32 at the interior perimeter strip adjacent the rear opening of the shield. In embodiments lacking the airflow channel 53, a singular flexible connector clip 114 may span the entire rear segment 34B of the shell’s boundary edge from one end of the front segment 34A at one end of the frontal region’s lower marginal area 44 to the other end of the front segment 34A at the other end of the frontal region’s lower marginal area 44.

In either case, the flexible connector clip(s) 114 may be used to attach a shroud to the shield. For such purposes, an exposed outer side 118A of stem 118 (the side opposite the overbent hooking portion 116) is equipped with a deposit of hook or loop fastener material 122, whether a continuous strip thereof spanning the full extruded length of the flexible connector clip, or discrete pieces of fastener material attached at spaced apart locations therealong. The shroud (not shown) is equipped with a mating deposit of loop or hook fastener material along a perimeter of the shroud. Accordingly, fastening together of hook and loop material on the shroud and the flexible connector clip 114 is operable to secure the shroud to the shell 32. Inside the shell 32, additional hook or loop fastener material may be applied across the rear end of the airflow channel 53 and on the neighbouring internal areas of the shield on either side of the airflow channel, in order to also mate with the loop or hook fastener material on the shroud, thereby achieving fastened connection of the shroud around the entire rear segment 34B of the shell’s boundary edge 34. Double sided tape or snap fasteners may alternatively be used in place of the hook and loop fastener to similarly enable convenient quick assembly by a customer or end-user from initially separate components. Alternatively, the shroud and the one or more connector clips 114 may instead be combined into a singular unit by a manufacturer or supplier, for example where the shroud is pre-sewn, pre-bonded with suitable adhesive, or even heat sealed to the stem of the flexible connector clip(s) 114.

It will be appreciated while the illustrated disposable embodiments of the cranial extension device 30 are described as being made of thin-walled, shape-retaining but flexible polymer (e.g. lightweight polyethylene terephthalate (PET) or polypropylene), whose described shape is imparted by thermal forming or vacuum forming, other disposable embodiments may employ other light-weight disposable materials, for example molded paper/cardboard of the type employed in the packing industry.

Other optionally-reusable embodiments may employ a rigid structure capable of also withstanding light impact, for example for use in industrial applications where a thicker more rigid face shield is worn to similar withstand impact, in which case the shell 32 may be made of harder and/or thicker plastics, for example acrylonitrile butadiene styrene (ABS). Such embodiments may require increase in the total surface area of hook or loop fasteners used to secure it to the face shield, whether by using a larger singular piece occupying an entirety or majority of the front marginal area of the shell, or a greater quantity of individual fastener pieces. Alternatively, snaps or other releasable mechanical fasteners may instead be used, as may also be the case for the various disposable embodiments. The greater of weight of the impactresistant optionally-reusable embodiments may optionally be borne through a combination of not only the releasably fastened connection to the face shield, but also an optional one or more blocks or otherwise-shaped pieces of foam or other padding material adherable to the interior surface of the shell at the top of its interior space. This internal padding would rests against all or some of the cranial region of the user’s head, so that the weight of the extension device 30 is borne partly thereby and doesn’t create a tilt-inducing moment force on the face shield.

Such foam padding for the extension device 30 is preferably not pre-attached to the shell by the manufacturer or distributor, and is instead only applied on-site at the intended location of use, as is also preferably the case for the foam padding 18 of the disposable face shield. Accordingly, large quantities the shells 32 can be stacked together in flush nested relationship with one another for space efficient storage and shipment, together with unattached foam padding attachments. Likewise, the shell’s fasteners 42 may optionally be delivered as unattached components from the manufacturer or distributor for subsequent application thereof the shells 32 at the intended site of use, where corresponding shield fasteners 44 optionally included in the same shipment are likewise to be applied to the face shields as part of the on-site assembly process. This way, a newly, or separately, delivered inventory of the extension devices can optionally be assembled onto an existing, or separately delivered, inventory of face shields to improve the effective coverage area thereof. In any embodiments, whether disposable or reusable and flexible or rigid, the shell can be made sufficiently large to be one-size-fits-all, or various different sizes (e.g. small, medium, large) may be made to better accommodate head size variability.

It will also be appreciated that novel ventilation providing features of the various embodiments disclosed herein, such as the internal airflow channel 53 disposed between externally recessed troughs in the scalp section, functionally tapered brow ridge airspace 62 between forehead depressions 48 of the frontal region for encouraging upward flow of warm air from the facial region for overhead exhaust thereof from the rear of the shell, and/or the divergence of the scalp section at more than 90-degrees to the frontal region’s lower margin area to impart a sloped incline to the scalp section and thereby create a rearwardly growing clearance space atop the head for optimal ventilation may be employed regardless of whether the shell is particularly one designed for mounting onto a conventional face shield, or is designed to be self- supporting independently of the face shield, or is designed to support both itself and a face shield optionally mounted thereon, for example a movable flip-up face shield movably coupled to the shell 32.

Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.