Sam Sasan Navidi

49913921, Feb 12, 1991

Mar 6, 1990

7/489022

Gary L. Goldberg - San Diego CA
Sam S. Navidi - Poway CA
Wendell E. Reed - Chula Vista CA

Sundstrand Corporation - Rockford IL

F02D 3500

60 39281

In order to control fuel flow at a fuel delivery point for auxiliary power units, and for other low fuel flow applications, an altitude-sensitive fuel flow control device (10) includes a fuel inlet (12) in communication with a fuel source and a fuel outlet (14) in communication with a fuel combustor. The device (10) includes an axially extending rod (16) having a metering surface (22) intermediate the ends (24, 26) thereof which may be located in various positions relative to a fuel flow path (18a, 18b, 18c, 18d, 18e) extending from the fuel inlet (12) to the fuel outlet (14) by axial movement of the rod (16) which varies fuel flow within a preselected range of altitude-dependent fuel flow rates. In order to move the axially extending rod (16) to variously position the metering surface (22) relative to the fuel flow path (18a, 18b, 18c, 18d, 18e), an aneroid bellows (28) movable responsive to changes in ambient pressure is interconnected with the axially extending rod (16) and a differential pressure regulaator (52) is in communication with the fuel flow path (18a, 18b, 18c, 18d, 18e) upstream and downstream of the metering surface (22) for maintaining a constant pressure drop independently of altitude.