Patent Description:
Face shields are often used to protect a user's eyes and face while performing certain tasks such as grinding or pressure washing. Over time, the lenses of face shield systems can either become dirty, contaminated, or experience wear due to the debris the face shields are designed to deflect. As a result, some conventional face shields allow for removal and replacement of these lenses. Conventional lens replacement requires significant time and effort to remove the used lens and install the replacement lens.

The face shields can further integrate a positive air pressure respirators which provide the additional benefit of supplying purified air to the wearer without requiring the user to don additional personal protective equipment, such as a separate respirator. As with the lenses, the materials used to create a seal to a wearer's head may become dirty or worn. The traditional systems also often require significant time and effort to remove the used lens and install these seal components, or else may be prone to inadvertent release. <CIT> discloses a replaceable lens attachment system for respiratory devices and methods of use.

Face shield systems for securing removable face shield lenses are disclosed, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.

The figures are not to scale. Where appropriate, the same or similar reference numerals are used in the figures to refer to similar or identical elements.

Individuals wear face shields for protecting the wearer's face from various harms. Commonly, face shields are used to protect an individual from airborne debris from metalworking or similar processes during activities such as grinding or cutting with power tools. Face shields can also guard against sprays from various sources, such as pressurized piping or even sneezing humans. Unlike safety glasses, a face shield protects the entire face instead of just the wearer's eyes from the hazardous debris. This configuration also minimizes the risk of debris reaching the eye from more angles angle as compared to traditional safety glasses while also limiting obstructions to peripheral vision.

Traditional face shields often use a flexible polycarbonate lens. Though many of the traditional face shields may have replaceable lenses to allow for exchanging damaged or worn lenses, the wearer may be hesitant to replace the lens because of the time intensive and difficult process involved. The traditional process often includes bending both the lens and/or the shell of the face shield in which the lens is mounted. The shell often has a series of channels in which the user must insert the lens while either the lens and/or the shell are distorted. Improper installation may result in a gap between the lens and the shell creating an opening for debris to get past the shield. Additionally, an improperly installed lens may not provide the full protection against debris impact. By simplifying the process, a user could potentially remove and re-install the face shield lens without removing the face shield shell from the user's head allowing for greater flexibility of lens selection such as tinted lenses for bright light environments.

Relatedly, the hazardous types of work that require a face shield also often also require breathing protection in the form of a respirator. In many cases, the user will wear the respirator underneath the face shield. Standard respirators are often bulky, heavy, may restrict breathing, and/or require special fitting tests prior to use. Some systems integrate these requirements into the face shield in the form of a Positive Air Pressure Respirator ("PAPR"), sometimes also referred to as a "Powered Air Purifying Respirator. " By adding a seal between the face shield and the user's head, an air hose can provide filtered air to the wearer's face while minimizing the negative effects of standard respirators. Additionally, these seals provide an additional barrier to the airborne debris reaching the user's face. The PAPR system further prevents the debris infiltration because the higher pressure creates an air barrier against particulate debris.

Disclosed are example face shield systems and methods for removing and installing various components of the face shield systems. In some example systems and methods, the face shield uses a removable face shield lens and a face shield shell which holds the lens during normal use. The face shield shell uses a lens lock to secure the lens for use, and further examples release of the lens for ease of replacement.

Also disclosed are example face shields with integrated using PAPR systems for breathing protection. The disclosed examples describe methods and systems for removing and replacing various components mounted to the face shield shell. By using mechanical attachment locations, these components may be removed and replaces with less effort and time. These systems also minimize the risk of inadvertent release of the attachment locations.

As used herein, the terms "first," "second," "third," etc., are used to enumerate instances of similar or identical elements, and do not indicate or imply order unless an order is specifically identified.

As used herein, the term "inner surface" refers to the portion of a given component closest to the user's head and the term "outer surface" refers to the portion of a given component away from the user's head.

Turning now to the drawings, <FIG> is an exploded view of an example face shield system <NUM> having a face shield shell <NUM>, a face shield lens <NUM>, and a head seal <NUM>. The face shield shell <NUM> provides the primary attachment point for the other portions of the face shield system <NUM>. For purposes of illustration, the user's head <NUM> is depicted.

In some examples, the face shield shell <NUM> includes lens locks <NUM>. In some examples, the lens lock <NUM> has at least two positions. During normal use, the lens lock <NUM> is kept in a locked position that prevents removal of the face shield lens <NUM>. When the user desires to replace the face shield lens <NUM>, the user places the lens lock <NUM> in the unlocked condition which allows the first face shield lens <NUM> to be removed and a second face shield lens <NUM> to be installed. Once the second face shield lens <NUM> is installed, the user returns the lens lock <NUM> to the locked condition to retain the face shield lens <NUM> within the face shield shell <NUM>. As shown, the face shield shell <NUM> covers the front portion of the user's face. In some examples, the face shield shell <NUM> could be integrated into a helmet which would cover the front of the user's face as well as the top of the user's head.

In some examples, the face shield system <NUM> also includes air ducts <NUM>, which may be coupled to air supply hoses via hose connectors <NUM> for connection to a PAPR system. The example air ducts <NUM> may cooperate with the inner surface of the face shield shell <NUM> to direct air from the hose connectors <NUM> into the face shield system <NUM> to enable the user to breathe the supplied air. The example ducts <NUM> include air outlets <NUM>, which direct the air toward the user's face. The outlets <NUM> provides the filtered air to within a cavity created between the face shield shell <NUM>, the face shield lens <NUM>, the head seal <NUM>, and the user's head <NUM>. In addition to providing the air for breathing, the air outlets <NUM> may also provide a cooling effect to the user and/or conduct expirations by the user away from the user's face.

The example The PAPR system may include a replaceable air filter to remove certain contaminants from the air. The air filter may conform to certain governmental standards such as the U. National Institute for Occupational Safety and Health (NIOSH), and be rated based on the amount and type of particulate filtered from the air. In some examples, the air supply device also includes an electrical motor for supplying the air through the system to the face shield system <NUM> via the ducts <NUM>. The electrical motor may be connected to a fan, a positive displacement pump, or other similar device. The air supply device draws air from the surrounding area, through the air filter, through the air supply device, and to the user's face within the face shield shell <NUM> via the hose connectors <NUM>, the ducts <NUM>, and the outlets <NUM>. In some examples, the air supply device may be worn by the user at the waist on a belt or on a harness on the user's back or chest.

In some examples, the air supply device monitors either the discharge pressure; a differential pressure, for example across the filter; or volume of airflow at the discharge of the air supply device. Low airflow can be a sign the air filter may need to be replaced. In some examples, the air supply device may provide an audible, visual, or haptic indication to the user to indicate the status of the filter or the need to replace the filter. The air supply device may provide these indications, or else send a signal to the face shield shell to provide these indications. In some examples, the filter life may be determined based on a time of use instead of, or in addition to, the pressure drop across the filter. In some examples, the status of the filter may be shown as a useful life percentage, a time remaining, a qualitative status (such as "good" or "needs replacement"), etc. In some examples, the air supply device may adjust the speed of the motor to maintain a constant output pressure or airflow through the air supply hose.

The head seal <NUM> closes any large gaps between the face shield shell <NUM> and the top of the user's head <NUM>. As described in more detail below, the head seal <NUM> may be attached to a shroud that extends from the head seal <NUM> to around the back of the user's head <NUM>. The number and size of gaps between the various components of the face shield system <NUM> and the user's head <NUM> are reduced or minimized. However, some air leakage is expected and required by the PAPR type system to vent excess air as well as the air exhaled by the user, thereby preventing infiltration of environmental gasses and/or contaminants into the interior of the face shield system <NUM>. The continual replenishment of filtered air minimizes the buildup of carbon dioxide, excess moisture, and other gasses from the user's breathing within the face shield shell <NUM>.

The example face shield system <NUM> further includes a chin seal <NUM> attached to the face shield shell <NUM> and configured to reduce gaps between the face shield shell <NUM> and the user's chin. In some examples, the chin seal <NUM> may include or be attached to a flexible (e.g., elastic) shroud that is biased into contact with the user's chin and/or neck.

The example face shield shell <NUM> is supported on the user's head by a headgear <NUM>. The headgear <NUM> securely attaches to the front, rear, and/or top of the user's head <NUM>, and may be adjustable to enable a comfortable and secure fit to different user's heads. The face shield shell <NUM> is coupled to the headgear <NUM> at pivot points <NUM> on the sides of the headgear <NUM> via pivoting clips <NUM>. The pivoting clips <NUM> couple the face shield shell <NUM> to the headgear <NUM> to support the face shield shell <NUM>. The pivoting clips <NUM> permit the face shield shell <NUM> to be pivoted with respect to the headgear <NUM>, in which the axes of rotation are the pivot points <NUM>.

The headgear <NUM> may operate as a suspension system and to provide attachment points for the face shield shell <NUM>. In this manner, the suspension system provided by the headgear <NUM> provides some flexibility between the rigid face shield shell <NUM> and the user's head <NUM>.

<FIG> is a front elevation view of the example face shield shell <NUM> of <FIG>, showing an exterior surface of the face shield shell <NUM>. <FIG> is a rear elevation view of the face shield shell <NUM>, showing an interior surface of the face shield shell <NUM>. <FIG> is a perspective view of the face shield shell <NUM>. The example lens locks <NUM> are located on one or both sides of the face shield shell <NUM>.

The example face shield shell <NUM> has a shell lock channel <NUM>. The shell lock channel <NUM> may be configured to accept the portion of a face shield lens locking channel of the face shield lens <NUM>. <FIG> is a more detailed view of a portion of the face shield shell <NUM> illustrating the shell lock channel <NUM>. The shell lock channel <NUM> may also provide support and/or a sealing location to the inner surface and outer surface of the face shield lens <NUM>.

The face shield shell <NUM> further includes a lens channel <NUM>. In the example in <FIG>, the lens channel <NUM> is at the bottom portion of the face shield shell <NUM>. However, the lens channel could be on one of the sides, the top of the face shield shell, or at an intermediary location between those areas. When installing the face shield lens <NUM>, the user first inserts the face shield lens <NUM> into the lens channel <NUM>. In some examples, the top of the outer surface of the lens channel <NUM> creates a lens insertion flange <NUM>. The lens insertion flange <NUM> abuts the face shield lens <NUM> to provide a hard stop for the user installing the face shield lens <NUM>. The shapes of the lens channel <NUM> and the lens insertion flange <NUM> aid in alignment of the face shield lens <NUM> during installation into the face shield shell <NUM>. In some examples, when the face shield lens <NUM> is fully installed into the face shield shell <NUM>, the lens channel <NUM> and lens insertion flange <NUM> provide support and a sealing surface to the inner surfaces of the face shield lens <NUM>.

In some examples, the face shield shell <NUM> will also have a face shield groove <NUM>. The face shield groove <NUM> may provide additional alignment for the other edges of face shield lens <NUM> adjacent the shell lock channel <NUM>. Due to the positive pressure created by the air supply device, minor leakage between the face shield shell <NUM> and the face shield lens <NUM> is permitted due to the lack of a gasket or other seal between the face shield shell <NUM> and the face shield lens <NUM>. In some examples, a gasket type material may be applied to the lens insertion flange <NUM> or the corresponding shell mating surface on the face shield lens <NUM> to further limit the air leakage around the face shield lens <NUM>.

The lens lock <NUM> extends through the face shield shell <NUM>. In some examples one or more lens lock tracks <NUM> may define the path of movement for the lens lock <NUM>. In some examples, the lens lock track <NUM> may be linear as shown. In some examples, the lens lock <NUM> will cover the lens lock track <NUM> in both the open and locked positions. In other examples, the lock track is curved. In some examples such as shown in <FIG>, the lens lock may snap fit into the inner surface of the face shield shell <NUM>. In other examples, the lens lock <NUM> may not extend through the inner surface of the face shield shell <NUM>. In yet other examples, the lens lock may rotate about a lock pivot point to engage the face shield channel.

<FIG> is a perspective view of the outer surface of the face shield lens <NUM>. <FIG> is a side elevation view of the face shield lens <NUM>, illustrating a shell locking channel <NUM> that may be used to selecting lock or secure the face shield lens <NUM> to the face shield shell <NUM>. The example face shield lens <NUM> is constructed of a uniform thickness polycarbonate plastic. However, other materials may be used.

In some examples, a user may possess a series of face shield lenses which may be tinted to varying degrees. The user may select a different tinted lens based on the working conditions and the task at hand. For example, the user may have an un-tinted lens for normal usage. The user may also have a dedicated tinted lens for work outdoors. The user may also have different tinted lens for grinding or welding operations. In some examples, the lens may be provide with auto-darkening features for welding purposes.

The example face shield lens <NUM> of <FIG> has locking channels <NUM> on either side of the lens <NUM>. The locking channels <NUM> engage the lens lock <NUM> of <FIG> when the locking channels <NUM> are inserted into the corresponding shell lock channels <NUM> and the lens lock <NUM> is moved into the locked position. When locked, the lens locks <NUM>, the shell lock channels <NUM>, and the locking channels <NUM> cooperate to hold the face shield lens <NUM> in place on the face shield shell <NUM>.

In other examples, portions of the face shield lens <NUM>, such as the locking channel <NUM> and/or portions in contact with the lens insertion flange <NUM>, may be thicker than the remaining portions of the face shield lens <NUM> to provide greater strength and rigidity to the locking channel <NUM>. In some examples, the lens lock <NUM> engages the locking channel <NUM> to create a tensile force on the face shield lens <NUM> to force the mating areas onto the face shield shell <NUM>. In other examples, the face shield lens <NUM> may have a locking channel <NUM> only on one side of the lens or at a different location on the lens such as the top or the bottom of the face shield lens <NUM>. In these other examples, the lens lock may use tension and/or compression forces as the lens lock <NUM> engages the outer surface of the face shield lens <NUM> to improve conformance of the face shield lens <NUM> to the lens insertion flange <NUM>.

As shown in <FIG>, the locking channel <NUM> is a linear shape to correspond to the lens lock track <NUM> of <FIG>. In other examples, the locking channel <NUM> may take other shapes to correspond to other configurations and/or other methods of mounting the lens lock <NUM> to the face shield shell <NUM> to allow the lens lock <NUM> to enter the locking channel <NUM> when in a locked position and exit the locking channel <NUM> when moved to the unlocked position.

The face shield lens <NUM> also has a channel centering indent <NUM>. The channel centering indent <NUM> may be configured to abut against the lens centering contour <NUM> to aid in the alignment of the face shield lens <NUM> centerline with the face shield shell <NUM> centerline.

As mentioned above, the lens channel <NUM> of the face shield shell <NUM> may improve alignment of the face shield lens <NUM> when inserted into the face shield shell <NUM>. As illustrated in <FIG> and <FIG>, the face shield shell <NUM> may align the lens <NUM> using a lens centering contour <NUM>. As illustrated in <FIG>, the face shield lens <NUM> has a corresponding channel centering indent <NUM>. As shown, when the user inserts the face shield lens <NUM> into the lens channel <NUM>, the channel centering indent <NUM> will abut against the lens centering contour <NUM> thus aiding the user to align the centerlines of the face shield lens <NUM> with the centerline of the face shield shell <NUM>. The user may align the channel centering indent <NUM> with the lens centering contour <NUM> prior to inserting the shell locking channels <NUM> of the face shield lens <NUM> into the shell lock channels <NUM> of the face shield shell <NUM>.

In some examples, the face shield lens <NUM> is at least <NUM> (<NUM> inches) thick. At this thickness, the face shield lens is unlikely to bend while inserted or removed from the face shield shell <NUM>, and/or may allow some flexing during insertion and removal from the face shield shell <NUM>, but provide adequate protection to the user during normal use.

In other examples, the face shield may only have a lens lock <NUM> on one side of the face shield shell <NUM> and a lens channel <NUM> on the opposite side. In some of these examples, the lens channel <NUM> may also have a lens insertion flange <NUM> and/or a lens centering contour <NUM>. Instead of aligning the centerlines of the face shield shell <NUM> and face shield lens <NUM>, the channel centering indent <NUM> and the corresponding lens centering contour would act to aid in the vertical alignment of the face shield lens <NUM>. In yet other examples, an interlocking hinge or other releasable feature may join the face shield shell <NUM> and face shield lens <NUM> opposite the side opposite of the single lens lock <NUM>.

In some examples, the face shield shell <NUM> may have a lens channel <NUM> at the bottom and/or top of the shell <NUM>, and have a single lens lock on the opposite horizontal edge. In this example, the face shield shell <NUM> may also have a second and/or third lens channel on either side of the face shield shell <NUM> to provide support to the inner and outer surfaces of the face shield lens <NUM>.

<FIG> is a side elevation view of the example face shield system <NUM> of <FIG>. The face shield system <NUM> of <FIG> illustrates one of the lens locks <NUM>, and the head seal <NUM> attached to a head shroud <NUM>. The head seal <NUM> creates a barrier to airflow between the face shield shell <NUM> and the user's head <NUM> in a PAPR type system.

The lens lock <NUM> of <FIG> slides between a locked position and an unlocked position. In the locked position, the lens lock <NUM> engages with the shell locking channel <NUM>, which is positioned within the lens channel <NUM>, to resist removal of the lens <NUM> from the lens channel <NUM>. For example, a protrusion <NUM> of the lens lock <NUM> extends into the lens channel <NUM>. When the lens lock <NUM> moves from the unlocked position (shown as unlocked position <NUM> in <FIG>) to the locked position (shown as unlocked position <NUM> in <FIG>) while the shell locking channel <NUM> is seated in the lens channel <NUM>, the protrusion <NUM> moves into a locking engagement with the shell locking channel <NUM>, which may involve further tightening the lens <NUM> against the lens insertion flange <NUM> due to the angle of the shell locking channel <NUM> with respect to the protrusion <NUM>. To release the lens <NUM>, the protrusion <NUM> is moved to the unlocked position <NUM> by sliding the lens lock <NUM> to the unlocked position, which may be marked on the shell <NUM>.

The example head seal <NUM> is attached to an interior surface of the shell <NUM>, near the upper rear edge of the shell <NUM>. For example, the interior surface of the shell <NUM> may include a seal channel into which the head seal <NUM> is seated to limit air flow between the head seal <NUM> and the shell <NUM>. <FIG> is a more detailed view of the example head seal <NUM>.

As illustrated in <FIG>, the head seal <NUM> may be attached to the shell <NUM> near the pivoting clips <NUM>. <FIG> is a cross-sectional view of the face shield system <NUM> illustrating the head seal <NUM> attached to the shell <NUM> and the air ducts <NUM>. The example head seal <NUM> includes clips <NUM> that support the head seal <NUM> via corresponding protrusions <NUM> from the air ducts <NUM>. The head seal <NUM> further includes locking tabs <NUM> arranged on a circular portion <NUM> of the head seal <NUM>. The circular portion <NUM> permits the head seal <NUM> to be attached to the shell <NUM> around the pivoting clips <NUM>.

In some examples, the head seal <NUM> and/or the chin seal <NUM> are constructed from a molded plastic, 3D printed plastic, silicone, and/or any other appropriate material.

The example head seal <NUM> is attached to the shroud <NUM>, which may then be wrapped over the user's head <NUM>. In the example of <FIG>, the shroud <NUM> is sewn to the head seal <NUM>. However, other methods of attachment may be used based on the materials of the shroud <NUM> and/or the head seal <NUM>, such as gluing or other adhesion, ultrasonic welding, clipping, clamping, and/or any other techniques. In the example of <FIG>, the shroud <NUM> is sewn to the side of the head seal <NUM> that contacts the shell <NUM>. In this manner, the head seal <NUM> may be constructed to be thin enough that the head seal material can be pierced by a sewing needle for attachment of the shroud <NUM>. The shroud <NUM> may further be provided with an elastic edge opposite the edge attached to the head seal <NUM> to improve conformity to the user's head <NUM> and limit air exchange from the volume under the shroud <NUM> (e.g., adjacent the user's head 108_with the environment.

In some examples, the shroud <NUM> may be further coupled to the chin seal <NUM> and extend down to the user's neck. In such examples, the elastic edge may be configured to permit the user's head <NUM> to pass through the elastic edge, and then contract the edge around the user's neck to limit air exchange without restricting the user's breathing or circulation. The shroud <NUM> may be constructed using any appropriate flexible, airtight material. In some examples, the shroud <NUM> may comprise an impregnated fabric, a closed cell foam, a plastic sheet, a woven plastic fabric, and/ any similar material or combination of materials.

<FIG> is a perspective view of the example lens lock <NUM>, and <FIG> is an elevation view of the lens lock <NUM>. As shown in <FIG>, the lens lock <NUM> includes the protrusion <NUM> which engages and disengages the shell locking channel <NUM> of the lens <NUM>. The example lens lock <NUM> further includes clips <NUM>, <NUM> that retain the lens lock <NUM> within the lens lock track <NUM>. The protrusion <NUM> and the shell locking channel <NUM> provide a limit on translation of the lens lock <NUM> in a first direction (e.g., a locking direction) along the lens lock track <NUM>. The example lens lock <NUM> includes a motion stop <NUM> that provides a limit on translation of the lens lock <NUM> in a second direction (e.g., an unlocking direction) along the lens lock track <NUM>.

As previously described, the lens lock <NUM> in described examples moves in a linear track. However, in other examples the lens locks may move along a curved track to lock and unlock the lens <NUM>. For example, the lens lock may have a curved shape instead of the linear shape as illustrated in <FIG>.

Additionally or alternatively, instead of a lens lock track, the lens lock may rotates about a lock pivot point. The lens locks mentioned may or may not use a similar shell lock channel as described above. In some examples, only the inner surface or the outer surface may be supported and used to create the seal around the lens lock.

In some examples, the lens lock may be provided with a backup lock to further prevent the lens lock <NUM> from being opened inadvertently while in use. For example, the backup lock may limit movement of the lens lock <NUM> until the backup lock is physically unlocked by the user, at which time the lens lock <NUM> may be moved. In other examples, the backup lock may rotate, may be a recessed spring loaded button, or any other similar configuration to limit or prevent the movement of the lens lock <NUM>.

In some examples, the lens lock <NUM> may be biased into a locked position by a biasing element. For example, a spring may be attached between the lens lock <NUM> and a stationary point on the face shield shell <NUM> to provide a tensile force to move the lens lock <NUM> from the unlocked position to the locked position and/or to help keep the lens lock <NUM> in the locked position. In other examples, the spring could be a rubber band, an air piston, or any other similar component to provide a biasing force.

While the present system has been described with reference to certain implementations, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope.

Claim 1:
A face shield, comprising:
a face shield lens (<NUM>) comprising a locking channel (<NUM>);
a face shield shell (<NUM>) configured to receive the face shield lens (<NUM>) when the face shield is inserted into the face shield shell (<NUM>); and
a lens lock (<NUM>) configured to move between:
a locked position (<NUM>) in which the lens lock (<NUM>) is configured to engage the locking channel (<NUM>) of the face shield to secure the face shield lens (<NUM>) to the face shield shell (<NUM>); and
an unlocked position (<NUM>) in which the lens lock (<NUM>) is configured to disengage the locking channel (<NUM>) of the face shield to permit insertion of the face shield to the face shield shell (<NUM>) and removal of the face shield from the face shield shell (<NUM>).