Drop tube assembly with shut-off valve and method for assembling the same

A drop tube assembly used to fill tanks from a delivery device connected to a source of liquid, the assembly comprising:

• a hollow drop tube having a length, a hollow interior, an exterior, an upper end, a lower end, a tapered part positioned below the outlet port, the tapered part being tapered inwardly toward the lower end, the drop tube being securable within the tank;
• the upper end including a fitting adapted for connection to the delivery device;
• a barrier sealing off the interior of the drop tube at a position along the length of the drop tube;
• an outlet port positioned above the barrier and fluidly coupling the hollow interior and the exterior;
• a restrictor sleeve having an inner surface inwardly tapered toward the lower end and slidably mounted to the drop tube, the restrictor sleeve slidably movable between a first position, at which the outlet port is unobstructed by the restrictor sleeve, and a second position, at which the restrictor sleeve at least substantially obstructs the outlet port;
• and
• float means, coupled to the restrictor sleeve, for slidably moving the restrictor sleeve on the drop tube between the first and second positions according to the amount of liquid in the tank, whereby when the restrictor sleeve moves to the second position, liquid movement into the tank is at least substantially stopped by the restrictor sleeve to prevent overfilling the tank, wherein the tapered part of the drop tube and the inner surface of the restrictor sleeve are sized so that there is a variable diametral clearance between at least a portion of the opposed inwardly tapered surfaces, irregardless of the position of the restrictor sleeve so as to aid free movement of the restrictor sleeve between the first and second positions.

A method for assembling a drop tube assembly comprising the following steps:

• selecting a hollow drop tube having an interior, an exterior, an upper end couplable to the liquid source and a lower end;
• sealing the interior of the drop tube at a barrier position along the drop tube;
• providing an outlet port through the drop tube above the barrier and through which liquid from the liquid source can flow from the interior of the tube and into the tank;
• mounting a restrictor sleeve to the exterior of the drop tube;
• coupling the restrictor sleeve to a float means for moving the restrictor sleeve between a first position, at which the outlet port is at least substantially unobstructed by the restrictor sleeve, and a second position, at which the outlet port is at least substantially but not completely obstructed by the restrictor sleeve so that liquid flow into the tank is at least substantially stopped, when the level of the liquid in the tank reaches a predetermined level, and providing a variable clearance between the restrictor sleeve and the drop tube adjacent the outlet port as said restrictor sleeve moves between said first and said second positions, wherein the not completely obstructed outlet port permits liquid in the drop tube to seep into the tank through said variable clearance so that liquid in the tube and liquid in the tank achieve hydraulic equilibrium.