Since nobody's rushing to answer, my two bits' worth: this may be an example of the notorious German penchant for 'Bildsprache'. The last time I encountered a 'xxxklammer' term of this sort, after a good deal of googling I discovered that it apparently took its name from a figure depicting the item in question as a forked box with the cross-section of an old-fashioned clothespin (not the American type with a spring, but the slotted rod type), which formed the interface between two other items (processes if I remember right).

You might consider 'transfer link' or 'transfer interface' if it fits the context.