Patent ID: 8261521

Claim:
A method of suspending a header from a towed implement to permit the header to float, the towed implement comprising a main frame, a sub-frame comprising a first side and a second side, and a four-bar linkage system comprising an upper link, a lower link, and an actuator, the method comprising: (a) operatively, pivotally attaching a first end of the upper link to the main frame of the towed implement using a first spherical bearing; (b) operatively, pivotally attaching a second end of the upper link to the first side of the sub-frame using a second spherical bearing; (c) operatively, pivotally attaching a first end of the lower link to the main frame using a first cylindrical bearing; (d) operatively, pivotally attaching a second end of the lower link to the first side of the sub-frame using a third spherical bearing in such a way that the upper link is not parallel to the lower link; (e) operatively, pivotally attaching the actuator to the first side of the sub-frame at a point lower than the second end of the upper link and higher than the second end of the lower link; (f) operatively attaching the header of the towed implement to the second side of the sub-frame, and (g) operatively rotatably attaching at least one ground engaging wheel to the main frame along a substantially horizontal axis, the main frame being fixed with respect to the horizontal axis of the ground engaging wheel.