Chuck -- Meine deutsch sehr sehr schlect ist! (My German is very very poor.) I learned German nearly 50 years ago from a man who fled Germany in 1932 and (A) it has been a long time since I used it more than trivially and (B) the German language was completely redone after reunification. We had a bunch of German exchange students some years ago and they all told me, "You sound like my grandfather!"
In any case, what you are looking at is traditionally known as a gooseneck clamp. The key here will be to use something like a pair of setscrews to establish perfect clamping when the t-slot screw (and, I assume t-slot key) is tightened. The tips of the (half-dog, recommended) setscrews allow "adjustment" for variations, wear, and cumulative deflection of the clamp.