Obturator rings are a specific type of piston ring used in World War I aero engines to compensate for warping of the cylinders. ==Purpose== The rotary aircraft engines of World War I (engines with the crankshaft fixed to the airframe and rotating cylinders) were notoriously difficult to keep cool when operating. Thus, their very thin walled steel ...
Found on
http://en.wikipedia.org/wiki/Obturator_ring
An L-section ring fitted round a piston to maintain a gas-tight seal between the piston and the cylinder wall.
Found on
https://www.encyclo.co.uk/local/20784
No exact match found.
