DUST-PROOF RESPIRATOR Russian patent published in 1996 - IPC

FIELD: means of individual protection of respiratory organs of workers of various branches of national-economy. SUBSTANCE: the respirator uses a filter half-mask, obturator, head-band, nose clip. The respirator half-mask is made up of two symmetric parts joined by a weld. Each part of the half-mask is made as a complex figure formed by a trapezoid, with its layer base matched with the segment forming the line of obturation in the nose area by an arc with a radius selected within 1.4 to 1.6 of the trapezoid height with a smooth connection along the lateral axis of symmetry of the trapezoid to an arc with a radius selected within 3.2 to 3.5 of the trapezoid height, forming the line of obturation in the area of the chin, and the lateral side of the trapezoid in the nose area is positioned at an angle to the larger base selected within 50 to 60 deg.; the other lateral side with respect to the larger base of the trapezoid is positioned at angle within 40 to 50 deg. ; the points of intersection of the smaller base of the trapezoid with the lateral sides, and of the lateral sides of the trapezoid with the segment arcs are smoothly connected by an arc with a radius selected within 0.4 to 0.6 of the trapezoid height. EFFECT: enhanced efficiency. 5 dwg