Abstract: A rotatably adjustable face mask valve includes a valve seat, a flap and a valve cover. The valve cover includes a fixed member and a movable member that is movable to different height positions relative to the fixed member and includes a pressing portion. When a user holds and rotates the movable member, the pressing portion is movable between a closed position of pressing against the flap, and an open position of separating from the flap. An opening on the valve seat is constantly in a blocked state when the pressing portion is in the closed position, or is subject to user's exhalation to change between the blocked state and a circulating state when the pressing portion is in the open position. Thus, the user may adjust the usage state of the face mask valve according to personal need and change the way the exhaled air leaves the face mask.

Abstract: A respiratory protection mask includes detachably connected main body and front cover. The main body includes a shielding member for shielding a wearer's mouth and nose, and has air outlet with air-outlet valve and air inlets with air-inlet valves. The mask is characterized in a guide structure and a limiting structure provided between the main body and the front cover. The guide structure includes corresponding slide rail and slide channel capable of guiding the front cover to move along a linear path parallel to a longitudinal section of the air outlet to assemble to the main body and cover the air-outlet valve. The limiting structure includes corresponding male and female fasteners that are detachably engaged with each other when the front cover is assembled to the main body, preventing the front cover from moving in an opposite direction on the linear path to separate from the main body.

Abstract: A retractable respiratory mask of the present invention comprise a worn portion, a filter portion adapted to connect with a filter member, and a retractable portion; the retractable portion connected between the worn portion and the filter portion comprises a first bend portion, a second bend portion and a displacement section. The two bend portions are spaced apart from each other and the displacement section is connected between the two bend portions. The retractable respiratory mask of the present invention can change the relative position between the two bend portions by folding over the displacement section. The retractable respiratory mask shows an extended shape when the first bend portion and the second bend portion are orderly arranged in an extending direction, and conversely shows a contracted shape when two bend portions are arranged along the opposite direction. By doing so, the mask can be folded up to reduce entire volume.

Abstract: A valve structure for a respirator includes a base, an upper cover, a membrane and a discharge device, wherein an outer side of an upper annular wall of the upper cover is provided with multiple L-shaped engagement blocks, and a combination hole of the discharge device is provided with multiple L-shaped engagement blocks embedded with the L-shaped engagement blocks of the upper annular wall, so that the discharge device is combined with the upper cover.