Link-Belt and Sumutomo have been together since the early eighties on excavators. They were the small ones at first, 2650, 2700, 2800 and 3400 size were all made in Japan by Sumutomo. Link-Belt made the 5400, 5800, 6400 and 7200 in Kentucky. Link-Belt cranes were always made in Kentucky.
Drott, Case and Poclain were owned by Tennico Corporation until sometime in the late eighties. Poclains were marketed by Case in the United States. Poclain made the twenty ton and larger units while Case concentrated on the smaller machines in the Drott product line. The Case product line was inexpensive and built to stay that way. The didn't provide a long service life and their cost per hour went sky high after a few thousand hours of operation. The Poclain line was usually priced in the premium market, had very poor factory and dealer support and the sky was the limit as far as cost per hour was concerned.
Case bought itself out of Tennico sometime in the eighties and formed some kind of joint partnership with Sumitomo in the early to mid nineties. They got the new model of machines before the Link-Belt dealers did which caused a lot of confusion and plenty of hard feelings at the time.
I don't know what all is happening nowdays with either as their market share in my area of the country is very poor. Link-Belt has owned the logging market until the last couple of years with the Deere/Hitachi lines taking a big bite. There are a few companies using Link-Belt excavators as leverage to get better prices on the market leaders. Case seems to be completely out of the mid to large machine lines around here.