Adjustable probe holder

Claim 1

Apparatus for accurately locating an externally mountable sensing device within a substantially enclosed machine for electrically observing a body contained therein over a defined air gap, the apparatus comprising a mounting structure secured to the outside of the machine adjacent to the observed body and being arranged to support a probe assembly, the structure having an opening coaxially aligned with an opening formed in the machine and a reference surface positioned a predetermined distance from the observed body, a removable probe assembly supported within the mounting structure including, a plate receivable upon said reference surface having a threaded hole therein overlying the opening in the machine, an elongated probe holder being adapted to pass through said opening and having a threaded shank on one end thereof mated into said threaded hole in the plate and an electrical sensing element at the other end positionable in close proximity to the body to be observed, an adjusting means slidably mounted upon the shank end of the probe holder having at least one flat surface for contacting a complementary surface upon the shank whereby rotation of said adjusting means causes the probe holder to be threaded into or out of said plate, stop means operatively associated with the adjusting means for limiting the range of rotation thereof to prevent the sensing element from contacting the observed body, removable clamping means for securing the plate to said reference surface whereby the probe assembly is insertable and removable from said machine.