Abstract A pneumatic control system having a source of control fluid providing two different control pressure levels for respectively switching the control device of the system from one operating condition thereof to another operating condition thereof, the control device comprising a pair of condition controller means each having a sensor and a bleed-type pneumatic valve operated thereby together with relay means operatively interconnected to the source for directing a branch signal of the control fluid to a pneumatically operated device in relation to a pilot signal directed to a pilot chamber of the relay means by one of the control means. First and second passage means are adapted to respectively interconnect the source to the valves of the control means, a pressure responsive means being disposed in the first passage means for preventing fluid communication therethrough when the source is at one pressure level and permitting fluid communication therethrough when the source is at its other pressure level. A switching means is provided in a third passage means and has one position for interconnecting only the second passage means to the pilot chamber whereby the pilot signal for the relay means is provided only by one of the controller means and having another position for interconnecting only the first passage means to the pilot chamber whereby the pilot signal or relay means is provided only by the other controller means.
In combination, a pair of housing parts having adjacent faces secured together, and a flexible diaphragm disposed between said adjacent faces to seal the same from each other, one of said parts having a cavity interrupting said face thereof and being disposed adjacent said diaphragm, said diaphragm having an opening passing therethrough aligned with said cavity, the other housing part having a tubular extension projecting from the face thereof and passing in a press-fit manner through said opening in said diaphragm and into said cavity and thereby having its exterior sealed by said diaphragm so that no leakage of fluid can take place between said tubular extension and said diaphragm and thereby enter the area between said diaphragm and said adjacent face of said other housing part even though said cavity is disposed outboard of said adjacent face of said other housing part adjacent said tubular extension thereof, said other part having a passage leading from the exterior thereof through said extension to thereby interconnect the exterior of said other housing part to said cavity.
Claim 2
Dependent Claim
175 words
In combination, a pair of housing parts having adjacent faces secured together, and a flexible diaphragm disposed between said adjacent faces to seal the same from each other, one of said parts having a cavity interrupting said face thereof and being disposed adjacent said diaphragm, said diaphragm having an opening passing therethrough aligned with said cavity, the other housing part having a tubular extension projecting from the face thereof and passing in a press-fit manner through said opening in said diaphragm and into said cavity and thereby having its exterior sealed by said diaphragm so that no leakage of fluid can take place between said tubular extension and said diaphragm and thereby enter the area between said diaphragm and said adjacent face of said other housing part even though said cavity is disposed outboard of said adjacent face of said other housing part adjacent said tubular extension thereof, said other part having a passage leading from the exterior thereof through said extension to thereby interconnect the exterior of said other housing part to said cavity.
Claim 3
Dependent Claim
49 words
A combination as set forth in claim 1 wherein said one housing part has another cavity interrupting said face thereof in spaced relation to said first-named cavity, said diaphragm sealing said other cavity from said face of said other housing part, and passage means fluidly interconnecting said cavities together.
Claim 4
Dependent Claim
32 words
A combination as set forth in claim 2 wherein said passage means is provided in said one housing part and interrupts said face thereof from said first-named cavity to said other cavity.