US Patent 7425036 Comfort belt spring pulley

An ergonomic device for a seat is disclosed. The ergonomic device includes a first side plate and a second side plate spaced apart from the first side plate. A hinge connects the second side plate to the first side plate. The ergonomic device also includes at least one pulley connected to the first side plate or the second side plate. A traction element is connected to at least one of the side plates, and the traction element has a cable wire generally wrapped about the at least one pulley. The traction element engages the pulley to at least partially collapse the hinge when a tractive force is applied to the traction element.