Patent ID: 11867191
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  H | IPC F  H

Claim 0:
1. An industrial fan assembly comprising:
a central hub having a first axis;
a plurality of blades operatively connected to and configured to rotate around the central hub; and
an anti-rotation device having a second axis, the second axis being perpendicular to the first axis, the anti-rotation device configured to prevent the plurality of blades from rotating in a reverse direction, the anti-rotation device comprising:
a substantially L-shaped lever having a long side and a short side;
a pulley operatively connected to the substantially L-shaped lever at a point where the long side and the short side meet, the pulley comprising a wheel on an axle or shaft configured to support a movement of the substantially L-shaped lever; and
a substantially flat plate attached to one end of the short side of the substantially L-shaped lever,
so that when the industrial fan assembly is OFF, airflow from the industrial fan assembly gradually stops and a weight of the substantially flat plate pulls the substantially flat plate downwards due to gravity to move the long side into a rotating path of the plurality of blades of the industrial fan assembly, interaction of the blades with the long side when the fan is rotated in the reverse direction biases the flat plate into contact against a surface on which the fan assembly is supported and that interferes with further movement of the flat plate and the long side thereby engaging the substantially L-shaped lever with the plurality of blades of the fan and locking a reverse movement of the plurality of blades, and
so that when the industrial fan assembly is ON, forward movement of the plurality of blades disengages the substantially L-shaped lever, and airflow is generated by the plurality of blades of the industrial fan assembly lifts the substantially flat plate upwards.