Berg has a cable chain product they call FLEX-EPITCH POSITIVE DRV that sounds a bit like what you are describing, but it has nowhere near the strength you require.
I'm having difficulty finding a product that I know exists, but I can't remember the proper terminology for which to search.
What I'm looking for is a steel cable that has cogs or segments attached to it, (kinda like the diamond cable saws for cutting granite), that can be engage with either spur or worm gear, causing the cable to advance along a path.
Basically what I need is something like the flexible rack-and-pinion setups, that are available, except I need a stronger setup. I would like to have a static pull of 800-1000lbs but I cannot even find the basic design that I'm looking for.
I have seen this in production use on the sun-roof on a vehicle. The roofs travel was actuated by a flexible cable that was moved by a worm gear.
Does anyone know the proper terminology for such a cable? I'm looking for a place to start my search for suppliers?
Doesn't meet your load requirements but could give you a place to start. "Synchromesh Cable" from sdp-si
You may also want to look at "bead chain" It's typically not used for anything except moderate loads but there could be a supplier that makes a load rated version.