Patent 8978794 was granted and assigned to Polaris Industries on March, 2015 by the United States Patent and Trademark Office.
A snowmobile rear suspension is shown comprised of a linear force element (LFE) positioned outside the envelope of the snowmobile endless track. The LFE is attached at one end to the frame and at the other end to a bell crank. The bell crank is operatively connected to the slide rails, and carrier rollers extend from the bell crank. When the slide rails collapse in normal operation, the bell crank strokes the LFE, and the suspension is progressive throughout the range.