Abstract: A method for adjusting a spacing of a leveling plate from a chamber body comprises attaching a mounting stud that includes a stud threaded surface to the chamber body. An adjustment screw is provided that has a first threaded surface threadingly engaged with the stud threaded surface. A bushing is provided that has a bushing threaded surface threadingly engaged with a second threaded surface of the adjustment screw. The bushing is movably coupled to the leveling plate. Coarse adjustment of the spacing between the leveling plate and the chamber body is made by rotating the adjustment screw with respect to the mounting stud. The bushing is fixed to the leveling plate. Fine adjustment of the spacing between the leveling plate and the chamber body is made by rotating the adjustment screw with respect to the mounting stud and the bushing.

Abstract: A device for adjusting a spacing between a chamber body such as a chamber body and a leveling plate such as a leveling plate comprises a mounting stud configured to be mounted to the chamber body. The mounting stud includes a stud threaded surface. A bushing is capable of being fixed to the leveling plate, and includes a bushing threaded surface. An adjustment screw has a first threaded surface threadingly engaged with the stud threaded surface of the mounting stud, and a second threaded surface threadingly engaged with the bushing threaded surface of the bushing. The threaded surfaces are configured, when the bushing is fixed to the leveling plate and the adjustment screw is turned, to cause the adjustment screw to move in a first direction with respect to the mounting stud at a first rate and the bushing to move in a second direction opposite from the first direction with respect to the adjustment screw at a second rate which is different from the first rate.

Abstract: A measuring instrument that includes a tube 21 having a female thread 211 and a spindle 3 having a lead screw 31 screwing with the female thread 211 and capable of being advanced and retracted in an axial direction along with rotation around the axial center, and measures dimensions etc. of a workpiece according to displacement in an axial direction of the spindle 3 based on a rotation amount of the spindle 3. According to this measuring instrument, a pitch P of the lead screw 31 is twice as large or more than the difference between an external diameter R and a core diameter r thereof, and the difference between the external diameter R and the core diameter r is one-fifth or less of the external diameter R. Because of the lead screw 31 with the large pitch, the spindle 3 can be moved at high speed, thus enhancing operational performance of the measuring instrument.

Abstract: A digital optical micrometer for mounting on an optical instrument and having an optical flat plano-parallel window which is connected to a micrometer drum. The drum can pivot or incline the optical plano-parallel window to cause displacement of a line of sight. The digital optical micrometer further has an LCD read-out that indicates the amount of displacement of the line of sight, a circuit that is connected to the optical plano-parallel window and provides an electrical signal having a signal property which varies in proportion to the inclination of the line of sight, and an analog-to-digital converter that is connected to the circuit and converts the electrical signal to a digital word having a binary value representative of the inclination of the line of sight. The optical micrometer further has a computer which has a clock input that provides for an automatic power down of the micrometer.

Abstract: A keratome includes a miniature differential micrometer having a barrel, a middle sleeve, and a inner sleeve connected by a threaded shaft having threads of two different pitches. One end of each of the middle sleeve and inner sleeve is drilled and tapped undersize and is slotted to conform resiliently to the threaded shaft. The middle sleeve is attached to a keratome by set screws drawing the middle sleeve into tight contact with the body of the keratome. The adjustable plate in the keratome is attached to the inner sleeve.