Locking mechanism for pyrometers

摘要

A pyrometer has a lock nut that engages a threaded sighting tube. The lock nut has a flange with a circle of thirteen apertures. A second similar flange is mounted on the body of the pyrometer which is restrained from rotation by splines which engage splines in the sighting tube. The second flange has a circle of only twelve apertures which is concentric with the circle of apertures on the first flange. The two flanges are locked together and the pyrometer is thereby locked in the sighting tube by means of a split pin pushed through aligned apertures. The different number of apertures in the flanges gives a number of locking positions that exceeds the number of apertures.