Breathing mask testing head comprises hollow rubber body fixed to top plate which plugs into bottom plate and uses inbuilt valves system and seals to seal pressurized body despite plate separation.

摘要

Valves built into top and bottom plates (1 and 2) allow the hollow rubber body (3) to be pressurized once the two plates are plugged together. The hollow body pressure is maintained constant when the two plates are separated. In operation when the plates plug together the valve plunger (4) is pressed by spring (5) onto the seal (6) as loaded by the pressure in the body (3). The hollow bolt (8) in plate (2) is forced up by the plunger to reinforce the seal (6) by the seal (9) round the bolt. Valve plunger (4) seals automatically when the plates are parted leaving the seals fully operative.