Patent ID: 7637367

Claim:
An over-under conveyor for transporting workpieces, said over-under conveyor comprising: a support frame having first and second ends and first and second spaced elongated side rails, each said side rail having an inside surface and a set of upper and lower chain guides fixed to said inside surface; first and second chain loops that form upper and lower moving chain tracks, each said chain loop being aligned with and slidably held by one of said sets of upper and lower chain guides; a plurality of flexible platforms movingly supported by said chain loops and adapted to carry the workpieces along at least one of either said upper and lower chain tracks, each said flexible platform having a plurality of substantially rigid elongated slats joined together by a flexible band, each of said slats having an inside surface and being spaced apart from an adjacent slat to form an elongated flex joint, each of said slats having first and second sets of upper and lower shoes extending from its said inside surface, each of said upper shoes being linearly aligned to supportably engage said upper chain tracks and each of said lower shoes being linearly aligned to supportably engage said lower chain tracks; a chain drive assembly having a drive shaft rotatably fixed between said side rails at said first end of said conveyor and an idler shaft rotatably fixed between said side rails at said second end of said conveyor, each said shaft including first and second sprockets, each said sprocket having a uniform diameter, said first chain loop fixed on said first drive and idler sprocket, said second chain loop fixed on said second drive and idler sprocket, said drive shaft rotating said sprockets to propel said chain loops in one direction along their said upper track and an opposite direction along their said lower track, said chain loops rotatably driving said idler sprockets and idler shaft; a platform inversion assembly having first and second pneumatic wheels with an outer friction surface, each of said pneumatic wheels having a predetermined width and a diameter slightly larger than said uniform diameter of said sprockets, said one of said pneumatic wheels being fixed to and rotatably driven by said drive shaft and said other of said pneumatic wheels being fixed to and rotatably driven by said idler shaft; and, wherein each of said platforms is propelled along said upper track until said platform meets one of said one pneumatic wheels and is propelled along said lower track until said platform meets said other of said pneumatic wheels, said platform riding up onto and frictionally engaging said friction surface of said pneumatic wheel and said pneumatic wheel flexibly compressing to receive said platform, and said slats of said platform flexing at each said flex joint around said pneumatic wheel as said pneumatic wheel rotates said platform to said other of said upper and lower tracks.