초록 ▼

A fan check valve is formed from plastic film having an outer edge and a central region. The valve also has a number of slits that define flaps in the film. The flaps are symmetrically arrayed in a spiral-like pattern between the central region and the outer edge. The valve mounts to the outer surfa

A fan check valve is formed from plastic film having an outer edge and a central region. The valve also has a number of slits that define flaps in the film. The flaps are symmetrically arrayed in a spiral-like pattern between the central region and the outer edge. The valve mounts to the outer surface of a tube axial fan. Under normal operating conditions, the fan moves a helical flow of air in a generally axial direction toward through the valve. The flaps are blown open and align with the oncoming flow at low angles of attack to minimize dynamic losses. The flaps are in the closed position and lie flush on the outer surface of the exhaust plate mounted on the fan at all other times to prevent airflow back through the fan in the opposite direction once the fan has failed.

대표청구항 ▼

[ We claim:] [1.] A check valve for a fan having a rotary axis and a grid that is substantially perpendicular to the axis, comprising:a resilient substrate adapted to be mounted to the grid of the fan, the substrate having a center point, a radially inward region and a perimeter;a plurality of flaps

[ We claim:] [1.] A check valve for a fan having a rotary axis and a grid that is substantially perpendicular to the axis, comprising:a resilient substrate adapted to be mounted to the grid of the fan, the substrate having a center point, a radially inward region and a perimeter;a plurality of flaps formed in the substrate, each of the flaps being defined by a slit having a radial edge segment with inner and outer ends extending from the inward region of the substrate toward the perimeter, and an outer edge segment extending transversely from the outer end of the radial edge segment; and whereinthe valve moves to an open position due to air pressure from the fan wherein the flaps flex axially away from the grid, and a closed position when air pressure from the fan ceases wherein the flaps are adapted to lie flush on the grid of the fan to prevent reverse airflow through the fan.