Gravity operated valve

1. A valve comprising:

a valve body defining a valve cavity;

first and second inlet ports, an outlet port, and a dump port each through the valve body; and

a weighted member positioned in the valve cavity and movable between a first position wherein the first inlet port is fluidically connected to the outlet port and the second inlet port is fluidically connected to the dump port and a second position wherein the second inlet port and the dump port are fluidically connected to the outlet port.

2. The valve of claim 1 , wherein the weighted member limits flow through the first inlet port in the second position.

3. The valve of claim 1 , wherein the weighted member limits flow between the second inlet port and the outlet in the first position.

4. The valve of claim 1 , wherein the valve has a valve top and a valve bottom, wherein the weighted member is positioned toward the valve bottom in the first position, and wherein the weighted member is positioned toward the valve top in the second position.

5. The valve of claim 1 , wherein the weighted member is movable between the first and second positions in response to changes in gravitational forces.

6. The valve of claim 1 , wherein the dump port has a smaller diameter than that of the first and second inlet ports and the outlet port.

7. The valve of claim 1 , wherein first inlet port and the dump port are both fluidically connected to a sump of a gas turbine engine, the second inlet port is fluidically connected to an auxiliary reservoir, and the outlet port is fluidically connected to a lubricating liquid pump.

8. The valve of claim 1 , wherein the weighted member comprises a material selected from the group consisting of steel and tungsten carbide.

9. The valve of claim 1 , wherein the second inlet port is fluidically connected to the dump port during all positions of the weighted member.

10. The valve of claim 1 , and further comprising:

an inner sleeve positioned inside the valve cavity between the valve body and the weighted member.

11. The valve of claim 10 , wherein the inner sleeve comprises:

a main sub-cavity containing the weighted member;

a second sub-cavity connecting the second inlet port to the dump port; and

a sub-cavity port connecting the main sub-cavity to the second sub-cavity when the weighted member is in the second position.

12. A method of operating a valve, the method comprising:

flowing fluid from a first inlet port to an outlet port and from a second inlet port to a dump port when the valve experiences gravitational forces exceeding a threshold; and

flowing fluid from the second inlet port and from the dump port to the outlet port when the valve experiences gravitational forces less that the threshold.

13. The method of claim 12 , wherein the valve includes a valve body and a weighted member, wherein the weighted member is in a first position with respect to the valve body when the valve experiences gravitational forces exceeding a threshold, and wherein the weighted member is in a second position with respect to the valve body when the valve experiences gravitational forces less that the threshold.

14. The method of claim 13 , wherein the threshold is greater than 0 g and less than 1 g.

15. The method of claim 13 , and further comprising:

flowing fluid from each of the first inlet port, the second inlet port, and the dump port to the outlet port when the weighted member is between the first and second positions.

16. The method of claim 12 , and further comprising:

supplying lubricating liquid from a sump to the first inlet port;

supplying lubricating liquid from an auxiliary reservoir to the second inlet port; and

pumping lubricating liquid from the outlet port to a bearing of a gas turbine engine.

17. The method of claim 12 , wherein the fluid flowed from the dump port to the outlet port includes air bled in through the dump port when the valve experiences gravitational forces less that the threshold.

18. A method of operating a valve having a valve body and a weighted member, the method comprising:

flowing fluid from a first inlet port to an outlet port and from a second inlet port to a dump port when the weighted member is in a first position with respect to the valve body;

applying a pressure from the second inlet port tending to bias the weighted member toward a second position with respect to the valve body; and

flowing fluid from the second inlet port to the outlet port when the weighted member is in the second position.

19. The method of claim 18 , wherein the weighted member moves from the first position to the second position when the weighted member experiences gravitational forces less than a threshold.

20. The method of claim 19 , wherein the threshold has a value greater than zero gravity.