Combination valve assembly with actuatable overfill relief
An exemplary embodiment of a combination valve assembly comprises a valve housing, an overpressure vent valve, a fill valve and a movable liquid overfill seal. The valve housing includes a longitudinal axis. The overpressure vent valve relieves excess pressure from the tank to which the assembly is affixed. The fill valve includes a fill valve pin actuatable between an open and closed configuration. The overfill seal is movable between a fluid sealing position and a fluid releasing position, and is elastically biased toward its fluid sealing position. In its fluid sealing position, the overfill seal prevents liquid from escaping the tank through the dip tube and outward of the valve assembly. Actuation of the fill valve pin toward its open position and movement of the overfill seal toward its fluid releasing position are preferably configured to both occur in the same direction, which is substantially parallel to the longitudinal axis.
1. A combination valve assembly comprising:
a valve housing member having a generally right cylindrical shape and including a first end, a second end and a longitudinal axis extending therebetween, said valve housing member having a vent valve socket, a fill valve socket and an overfill channel, each substantially extending from said second end toward said first end;
a dip tube at least partially inserted within said overfill channel and extending outwardly of said second end;
an overpressure vent valve disposed within said vent valve socket and having a pressure holding and a pressure relief configuration, said overpressure vent valve being elastically biased toward its pressure holding configuration, said elastic bias adapted to being overcome by a fluid pressure at said second end in excess of a pre-determined safe value;
a fill valve disposed within said fill valve socket and having a fill valve pin actuatable between an open and a closed position, said fill valve allowing fluid to flow therethough when said fill valve pin is in its open position, said fill valve being adapted to prevent fluid from flowing therethough when said fill valve pin is in its closed position, said fill valve pin being spring biased toward its closed position; and
an overfill seal element being movable between a fluid sealing position and a fluid releasing position, said overfill seal element preventing fluid from flowing through said overfill channel when in its fluid sealing position and allowing fluid to flow through said overfill channel when in its fluid releasing position, said overfill seal element being resiliently biased toward its fluid sealing position, said resilient bias being provided by a seal bias spring secured within said overfill channel, the seal bias spring being disposed between and in mutual axial alignment with said dip tube and said overfill seal element;
wherein said actuation of said fill valve pin toward its open position and said movement of said overfill seal element toward its fluid releasing position are configured to both occur in a direction substantially parallel to said longitudinal axis and toward said second end.
2. A combination valve assembly as defined in claim 1 further comprising an annular seal element and a second seal member, said annular seal element being axially retained substantially between said fill valve and said first end in concentric alignment with said fill valve socket, and said second seal member being axially retained substantially between said overfill seal element and said first end in concentric alignment with said overfill channel.
3. A combination valve assembly as defined in claim 2 further comprising a guide element affixed to said valve housing member at least in part to provide said axial retention of said annular seal element and said second seal member.
4. A combination valve assembly as defined in claim 3 wherein said guide element is a unitary component made substantially of a polymer.