Patent ID: 8183812

Claim:
A synchronous fan system comprising (a) a livestock shelter including a roof and floor; (b) live stock in said livestock shelter; (c) at least first and second spaced apart fans each suspended from said roof and including (i) a housing, (ii) a fan blade rotatably mounted on said housing, (iii) a motor mounted on said housing to rotate said fan blade, and (iv) a shaft including a proximate end connected to said housing and including a distal end extending upwardly from said housing, (d) a motor connected to said distal end of said shaft of said first fan to oscillate said shaft of said first fan; (e) a motor connected to said distal end of said shaft of said second fan to oscillate said shaft of said second fan; (f) a control unit to synchronously calibrate intermittently said first and second fans by rotating said shafts of each fan to (i) contact simultaneously a common hard stop position, and (ii) simultaneously move each fan away from said common hard stop position to oscillate generally synchronously between a selected pair of common steady state points.