US 12,449,049 B2
Check valve for RAT restow pump
Przemysław Kiełczykowski, Kiełczów (PL); Damian Adam Słodczyk, Wrocław (PL); Janusz Michał Sarosiek, Wrocław (PL); Piotr Michał Bereszyński, Głogów (PL); and Tomasz Marek Skórka-Siemieński, Wrocław (PL)
Assigned to HAMILTON SUNDSTRAND CORPORATION, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Feb. 22, 2024, as Appl. No. 18/584,375.
Claims priority of application No. 23461520 (EP), filed on Feb. 23, 2023.
Prior Publication US 2024/0287951 A1, Aug. 29, 2024
Int. Cl. F16K 15/04 (2006.01); B64D 41/00 (2006.01); F04B 53/10 (2006.01)
CPC F16K 15/042 (2013.01) [F04B 53/1005 (2013.01); F04B 53/1007 (2013.01); F04B 53/109 (2013.01); F16K 15/044 (2013.01); B64D 41/007 (2013.01); F04B 53/1015 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A check valve assembly comprising:
a housing having a fluid inlet arranged to be fluidly connected, in use, to a source of hydraulic fluid;
a first stage body having a first stage fluid outlet and a second stage body having a second stage fluid outlet and a flow passage between the first stage body and the second stage body,
wherein the first stage body is a hollow body having a first end in fluid communication with the fluid inlet and housing a hollow first stage retainer around which is mounted a first stage spring that biases a first stage ball;
wherein the second stage body is a hollow body housing a second stage retainer around which is mounted a second stage spring that biases a second stage ball;
wherein a first stage pressure differential between the first stage fluid outlet and the fluid inlet creates a fluid flow path from the fluid inlet to the first stage fluid outlet and causes the first stage ball to press against a bias of the first stage spring to close the flow passage between the first stage body and the second stage body;
wherein removal of the first stage pressure differential causes the first stage spring to return the first stage ball to its biased position to close the flow path from the fluid inlet to the first stage fluid outlet and to open the flow passage between the first stage body and the second stage body; and
wherein a second stage differential pressure between the flow passage and the second stage fluid outlet presses the second stage ball against a bias of the second stage spring to open a second stage fluid flow path between the flow passage and the second stage fluid outlet.