Abstract: A blower assembly for a powered air-purifying respirator (PAPR) assembly includes: a lower housing; an upper housing connected to the lower housing, such that the upper housing and the lower housing collectively define a first interior cavity; a filter configured to filter ambient air drawn into the blower assembly; and a fan. The upper housing and the filter define a pathway for a flow of air into the first interior cavity. The fan is positioned in the first interior cavity such that, when the fan is activated, ambient air is drawn into the blower assembly and travels along the pathway into the first interior cavity for subsequent delivery out of the blower assembly. The lower housing defines an outlet port for directing breathable air out of the blower assembly for delivery to a user (e.g., via a breathing tube interconnecting a headpiece and the outlet port).

Abstract: A filter assembly includes a first screen, defining a first flow passageway, a second screen, defining a second flow passageway, and a third screen defining a third flow passageway. The second screen is positioned between the first screen and the third screen. The first flow passageway is aligned with the third flow passageway and the second flow passageway is offset from the first flow passageway and the third flow passageway.

Abstract: A ratchet mechanism for a headband of a protective helmet controls movement of overlapping rear portions of the headband with respect to one another includes a housing defining an internal cavity. The ratchet mechanism further includes an adjustment element with a pinion configured to engage respective rack gears of the overlapping rear portions of the headband within the internal cavity defined by the housing, along with a spring, which provides a torque that biases the adjustment element to a home position. The ratchet mechanism further includes a knob that is configured for movement between a first position in which it engages the pinion and controls rotation of the adjustment element, and a second position in which it disengages from the pinion, such that the spring will return the adjustment element to the home position.

Abstract: A protective helmet adapted to receive and protect the head of a wearer includes an outer shell and an attachment ring removably secured to the outer shell, such that the attachment ring can be selectively attached to or detached and removed from the outer shell. The outer shell is shaped to protect the head of the wearer of the protective helmet and defines a bottom opening and an internal cavity for receiving the head of the wearer. The attachment ring acts as a point of attachment for, and thus secures, one or more components of the protective helmet configured to engage the head of the wearer, such that the components secured to the attachment ring are transported with the attachment ring when the attachment ring is detached and removed from the outer shell.

Abstract: A filter assembly includes a first screen, defining a first flow passageway, a second screen, defining a second flow passageway, and a third screen defining a third flow passageway. The second screen is positioned between the first screen and the third screen. The first flow passageway is aligned with the third flow passageway and the second flow passageway is offset from the first flow passageway and the third flow passageway.

Abstract: A ratchet mechanism for a headband of a protective helmet controls movement of overlapping rear portions of the headband with respect to one another includes a housing defining an internal cavity. The ratchet mechanism further includes an adjustment element with a pinion configured to engage respective rack gears of the overlapping rear portions of the headband within the internal cavity defined by the housing, along with a spring, which provides a torque that biases the adjustment element to a home position. The ratchet mechanism further includes a knob that is configured for movement between a first position in which it engages the pinion and controls rotation of the adjustment element, and a second position in which it disengages from the pinion, such that the spring will return the adjustment element to the home position.

Abstract: A scanning device including a controller and a light source operatively coupled to the controller. The light source is shaped and located such that at least part of the light emitted from the light source is reflected off of a document to be scanned, and the light source has a maximum output when the light source is fully warmed up. The scanning device further includes a receptor operatively coupled to the controller, the receptor being located to receive the light reflected from the document to be scanned such that the at least part of the visual properties of the document to be scanned are transmitted to the receptor in a scanning process. The controller is configured to selectively allow the scanning process to proceed when an output of the light source is less than about 80% of the maximum output.