Dual drive link conveyors and methods for chordal compensation

A link conveyor for an assembly machine comprising:

• a frame having a first end and a second end;
• an upper rail assembly, supported by the frame and comprising a first upper rail and a second upper rail, the upper rail assembly defining an upper channel;
• a lower rail assembly, supported by the frame and comprising a first lower rail and a second lower rail, the lower rail assembly defining a second channel;
• a chain comprising a plurality of interconnected links;
• wherein the upper channel and the lower channel cooperatively receive the chain;
• the upper rail assembly comprising a first upper chordal compensation cam, positioned at the first end of the frame, the first upper chordal compensation cam comprising a first upper deflection surface disposed on the first upper rail and a second upper deflection surface disposed on the second upper rail, wherein the first upper deflection surface and the second upper deflection surface cooperate to deflect the chain by a first upper variable deflection amount;
• wherein the first upper variable deflection amount reduces a deviation between a first velocity of the chain at the first end of the frame and a second velocity of the chain at the second end of the frame;
• a first sprocket, positioned at the first end of the frame and engaging the chain;
• a first motor drivingly engaging the first sprocket;
• and
• a second sprocket, positioned at the second end of the frame and engaging the chain.

A method for chordal compensation in a link conveyor, the link conveyor comprising

• a frame having a first end and a second end;
• an upper rail assembly, supported by the frame and defining an upper channel;
• a lower rail assembly, supported by the frame and defining a lower channel;
• wherein the upper channel and the lower channel cooperate to receive a chain;
• a first sprocket, positioned at the first end of the frame and engaging the chain;
• and
• a first motor drivingly engaging the first sprocket;
• the method comprising:
• providing a first upper chordal compensation cam in the upper rail assembly at the first end of the frame to deflect the chain by a first upper variable deflection amount;
• providing a first lower chordal compensation cam in the lower rail assembly at the first end of the frame to deflect the chain by a first lower variable deflection amount;
• configuring the first upper variable deflection amount and the first lower variable deflection amount to reduce deviation between a first velocity of the chain at the first end of the frame and a second velocity of the chain at the second end of the frame;
• providing a second sprocket at the second end of the frame to engage the chain;
• providing a second motor to drive the second sprocket;
• and
• providing a controller comprising a processor and a memory,
• configuring the controller to adjust the second motor to drive the second sprocket at about the second velocity.