Abstract: A miniature pneumatic switch apparatus has a diameter of three-eights inches and a height of five sixteenths inches and operates from minimal pressure to 100 psi. A pressure responsive unit includes outer spaced guide walls extending from a pressure movable wall. A switch unit is secured to the guide walls in spaced aligned relation to the movable wall and forms an operating chamber. A spring carrier is mounted within the chamber. The carrier includes a plate having a lateral opening with a beam spring extending therethrough, with the spring ends supported in openings aligned with the plate. An elastic band encircles the support walls and holds the beam spring in place. The opening in the plate facing the switch unit is a flat face, and the opposite face facing the movable wall is curved for line contact with the spring.

Abstract: A multi-stage pneumatic pressure regulator establishes a constant output pressure with a change in the output flow. The regulator includes a poppet valve connecting the input and output. A relief valve mounted on the poppet valve includes a first positioning diaphragm subjected to output chamber pressure and a vent hole to atmosphere. A pilot valve is mounted on the relief valve and includes a pressure chamber with a positioning diaphragm of a lesser area than the first diaphragm, coupled to the relief valve and opposing the first position diaphragm. A precision bleed orifice connects the pressure chamber to the input chamber and establishes a precise bleed. A presettable spring load orifice unit in the pilot valve couples the pressure chamber to the output chamber and passes the bleed flow to the output chamber and venting atmosphere. The pilot chamber pressure is greater than the output pressure and prevents feedback of the bleed. The poppet valve and pilot orifice have novel constructions.