GB472897A - Improvements in or relating to gas masks - Google Patents

Abstract

472,897. Gas-masks ; fastenings. NICOLAIDI, J. March 25, 1936, No. 8896. [Class 81 (ii)] [Also in Group XXV] A gas-mask 71, Fig. 11, of rubber or gas-proofed fabric is detachably connected at the sides and front to a collapsable head-piece 72, the frontal connection 1 also permitting swinging of the mask from the face without detachment. The head-piece 72 comprises a frontal band 19 pivotally connected at 20 to occipital bands 23 and lateral head bands 14, and a pair of central bands 13 connected respectively to the band 19 and to the overlapping ends of the bands 23. The pairs of bands 13, 14, have overlapping ends with holes such as 14<1> and are secured by a bolt and nut 25. the holes permitting adjustment of size of the head-piece. The bands 23 are similarly secured. The bands 13 are of flexible material permitting folding of the head-piece about the pivots 20 : the other bands may be flexible or of resilient metal or whalebone. In a modification flexible bands 13, 14, are secured at the crown by passing them through slots in a cruciform head plate. The head-piece 72 may be worn inside a helmet 73. The top corners of the mask have connecting pieces 11 engageable with hooks 22 on the head-piece and retained by springs 21, each part 11 comprising a wire loop 27, Fig. 6, connected to a block 30 retractable, to tighten the mask on the face, by a screw 31. The block 30 is slidable on a wire bail 29 holding the screw and pivotally connected at 28 to a plate secured to the mask. The front of the mask carries a rigid valve chamber 6 having hinged thereto at 5 a rod 4 secured to the mask and carrying a catch 1. The catch, Fig. 4, comprises a plate 3 carrying a spring bolt 1<1> retracted by a knob 2 and engaging a bridge 17 on a plate 16 spring- hinged to the head-piece band 19. Alternatively a pair of spring jaws 51, Fig. 10, on the mask may be engaged with a pin 49 on the band. The valve chamber 6, Fig. 8 comprises an exhaling compartment 34, having a rubber disc valve 35 and an outlet aperture 35<1>, and an inhaling compartment connected to a filter by a pipe 7 and having a rubber disc valve 38. A microphone 37 mounted in the inner wall is connected to sockets, 39 or 40, for connection through flex and a jack to a loud-speaker worn on the person or to a telephone. The eyepieces 9 of the mask are provided internally with pads engaging the frontal bones.