Tabor steam engine indicator, in case with key

Tabor steam engine indicator, in case with key

In this instrument the parallel motion is obtained by causing a small roller attached to the pencil arm to travel in a suitably curved guide fixed on the indicator cylinder cover. The piston rod is attached to the piston by a ball-and-socket device, to prevent any tendency to bind, and with the same object the springs are double threaded. The paper drum is fitted with a detent stop motion, and a neat universal guide pulley gives a true lead to the cord from any direction.