Pressurized control signal apparatus

Pressure regulating temperature responsive apparatus comprising

• a. housing means for defining a chamber;
• b. port means extending through said housing means in continuous, unobstructed fluid communication with said chamber, and adapted for connection to a source of air having a variable pressure in excess of atmospheric pressure, for conveying said air into said chamber, and for transmitting a control signal therefrom, said control signal changing pressure in response to temperature;
• c. bleed valve means for bleeding air from said chamber;
• d. diaphragm means forming a wall of said chamber and operative to control and effect the flow of air out of said bleed valve means in response to an increase in pressure exerted on the diaphragm means by air within said chamber from said source of variable air pressure, thereby causing said control signal not to exceed a maximum pressure in excess of atmospheric pressure, said maximum pressure being determined by the summation of forces acting on the diaphragm means;
• and
• e. temperature responsive means adjacent said diaphragm means for directly exerting a force thereon, thereby biasing said diaphragm means to limit the pressure within said chamber to said maximum pressure in response to temperature.