Today in 1939, US Patent 2163817 A was issued, an invention of Eugene H. Wagner, for his “Draw Rod Adaptor.” There’s no Abstract, although in the description it includes this summary:

This invention relates to direct draw beer dispensing and cooling cabinets and more particularly to an adapter to accommodate a draw rod for either center or side tapping.

The principal purpose and object of my invention is to provide an adapter so constructed and arranged that by merely reversing the relative positions of its parts, the desired passageway out of the cabinet for a draw rod may be easily and quickly provided for either center or side tapping.

In accordance with my invention the adapter comprises a pair of separable block-like elements of the desired material and provided at their engaging surfaces, one with a pair of spaced grooves, and the other with a groove and a projection in the same spaced relation as the grooves in the other element so that the selected grooves may be made to register to provide a draw rod passageway through the adapter while the projection extends in to and closes the groove not being. used.