3pt Shocks?

I've seen references on the internet to some kind of shock or device that takes the Bounce out of the 3pt hitch. Does anyone know what this would be or if it is available for 4720's? We use snowblowers on our machines, and frequently are driving 16-17mph on the roads with a snowblower on the hitch - When you hit a big bump the blower really bounces hard. It would be nice to soften that a little bit, I'm sure it would be easier both on the tractor and blower, as well as the operator.

Can anyone point me in the right direction?


Thanks!