Load Balancing Pack Frame

I was fooling around with a load balancing pack frame idea on a backpack trip this week. A little googling showed that I was just reinventing the wheel. Check out this patent.

http://www.patentgenius.com/patent/4217998.html

Enlarge the first drawing, by couble clicking it, to get a good idea of how it might look.

Dj2,
These things have been around for at least 40 years. Simple mechanical analysis and experience show that they work no better than standard frames. They cannot actually shift the center of mass. The result is complexification and weight with no improvement in performance.

I recall that Jan Sport and others used to have a contraption attached to the waist belt shaped like a U on its side. Do you think that was their attempt to replicate this idea?

This basic idea has been made/reinvented in two forms: passive wrap-around frames like the Jansport you mention as well as the Coleman plastic frame; and active leveraging devices like the 'weight balancing' frame. To my knowledge, no one has mass produced any of active leveraging devices. They look good on paper if you don't look too closely, but the prototypes have failed to meet expectations. Notice the date on the patent application. The idea wasn't new then. It's just that it didn't work, so no one followed up. Wrap-around frames don't work that well either. The theory is that they place the pack weight over the hips, closer to the user's center of mass. Of course, that ignores the basic mechanics of leverage. All it really dies is enable the pack to sit up on its own. In the Coleman design it gives the plastic frame extra structural support that it needs.

Thanks for the helpful info.