Over the years, inventors have attempted to improve the adjustable wrench. In particular, there has been an effort to devise a wrench that puts pressure on more than just 2 flats of the bolt head or nut.
Above, a Craftsman 43380 "pocket socket" adjustable wrench. It is clearly designed to apply force to 4 flats, and also to be applicable in tighter spaces than would permit the use of a conventional Cresent-type adjustable wrench. It was patented by Richard Cone of Dayton, Ohio in 1990, who assigned the patent to the Midwest Tool and Cutlery Company (today, Midwest Snips). This firm apparently made it for Sears, which offered it in four sizes (6, 8, 10 and 12 inches) from 1997 to 2001. It's not a particularly useful design, and I expect it wasn't a big seller. It also has a very poor finish. I hung mine on a pegboard in a shed where I store firewood, and discovered the wrench a few months later totally frosted with rust. Cleaning it off on the wire wheel completely removed the label. As the saying goes, expect less from Sears.
Below, a Crescent RapidRench, which boasts a "7/8-inch adjustable jaw opening to accommodate 38 different bolt/nut sizes." How they came up with 38 sizes is beyond me. Anyway, it's still available, now with serrated jaws. I've never had an occasion to use mine.
Finally, my most recent thrift-store find, a Chinese-made CHL wrench. It was patented in the U.S. in 1995 by Chung-Hshing Chang of the Taiwan Province of China. I think it's a brilliant design, well thought-out, even to the arrow marks which relate the movement of knurled nut to the advancement of the screw acting as a jaw. It puts pressure on 3 sides of the fastener head, applying the force in a very positive fashion. I have been unable to find any reference to this tool on the web. Curious.