There was a small company that advertised in the back of Bycycling! magazine in 1973 or 74 or both that had a brake possibly called the power cam that worked with a similar principle as the later Shimano AX centerpull brakes.
It used a riser that was part of the brake to hold the cable end in position and thereby eliminate flex and distortion in the system.
Thought about ordering one or a pair but it was pointed out to me that there did not appear to be a provision for a quick release to allow easy wheel changes.
My father's Carlton Catalina had the front brake running through a hole in the stem and that firmed up the front brake quite well, just had to adjust the brake if one wanted to raise or lower the handlebars.
Palos Verdes Ca