Fig. 18. Large Beam Caliper
Fig. 18 shows a large beam caliper designed for machinists and patternmakers. It consists of a beam MN and the legs R and S, made of cherry wood to the dimensions indicated. The legs are secured in position on the beam by means of the thumb screws A, which jam against the gibs C at the points of the screws. The gibs have holes countersunk for the screws to enter, to hold them approximately in place, and the nuts B are of brass, fitted into the filling pieces P that keep them from turning. The filling pieces are riveted to the legs by means of cherry dowels D. One leg S is provided with a fine adjustment consisting of flexible steel spring H, ending in a point which is adjusted by the thumb screw E. This screw is locked in adjustment by the check nut G bearing against the brass nut F, which is inserted in the leg as shown.[[8]]
CHAPTER III
MICROMETER MEASURING INSTRUMENTS
Of all measuring instruments used in the shop intended for accurate measurements, those working on the principle of the ordinary micrometer calipers are the most common. In the present chapter we shall describe and illustrate a number of different designs of these tools, intended to be used for various purposes. The instruments shown in Figs. 19 to 23 were built, in leisure hours, by Mr. A. L. Monrad, of East Hartford, Conn.
Micrometer for Snap Gages
