Like you, I typically can't move fast enough for Shock Jockey alone to do the trick. The best strategy I've found involves using Possession on an armored machine gunner who's behind the Patriot, or opening up a tear to bring in a turret there. When the Patriot turns around to handle my ally, his gears are exposed to me, and then I can shock him and blast away. Alternatively, if the Patriot keeps focusing on me, at least my ally is shooting it in its gears, so it's not a total loss.
Of course this strategy will technically work with any ally type, but I've found that others — e.g. Mosquitoes and melee-only fighters — either don't distract Patriots very well or quickly get torn up by Patriot guns if they do. Also, this obviously requires you to be able to get in position to possess someone or open the tear in the first place; I've never found a good strategy for hitting the gears of a lone Patriot.
EDIT for DLC:
In Clash in the Clouds, Shock Jockey alone does work long enough for you to get around Patriots and shoot them in the gears. This is awesome for making money and running up the score, because gear shots give lots of bonus points/cash per shot. Shock a Patriot, get behind it and go to town with a low-damage, high-frequency gun like the pistol or machine gun. (You may need to apply extra shocks while you reload your gun.) For extra effect, use the Tunnel Vision gear and do not zoom in!