초록 ▼

A fluid level controller having a thermal expansion element in the form of cylinder made from polytetrafluoroethylene. The cylinder is located in a container which is connected to a supply of cryogenic fluid by a ball valve. When the cryogenic fluid in the container reaches the level of the cylinder

A fluid level controller having a thermal expansion element in the form of cylinder made from polytetrafluoroethylene. The cylinder is located in a container which is connected to a supply of cryogenic fluid by a ball valve. When the cryogenic fluid in the container reaches the level of the cylinder and cools it, the cylinder shrinks and causes a lever to close the ball valve. When the cryogenic fluid falls below the level of the cylinder, the cylinder expands and the lever opens the ball valve and permits cryogenic fluid to flow through the valve and into the container. The cylinder has a heating element disposed in its interior to hasten the response of the cylinder to a change in the fluid level.

대표청구항 ▼

A fluid level controller for maintaining at a predetermined level the cryogenic fluid provided to a container by a cryogenic fluid supply, said controller comprising: a valve disposed between the container and the supply for controlling the flow of fluid from the supply to the container, said valve

A fluid level controller for maintaining at a predetermined level the cryogenic fluid provided to a container by a cryogenic fluid supply, said controller comprising: a valve disposed between the container and the supply for controlling the flow of fluid from the supply to the container, said valve having a first open position wherein fluid is free to flow from the supply to the container and a second closed position wherein fluid is not permitted to flow from the supply to the container; a thermal expansion member disposed entirely within said container for being in direct contact with the fluid in the container when the fluid is at or above the predetermined level, and for being out of contact with the fluid when the fluid is below the predetermined level, said thermal expansion member cooled by the fluid and having a smaller physical dimension when in contact with the fluid; and valve actuating means coupled to said thermal expansion member for moving said valve from one of the first and second positions to the other of the first and second positions when said thermal expansion member comes into contact with the fluid in the container at least a portion of said valve actuating means being disposed within said container and adjacent to said thermal expansion member.