Angle tangent micrometer

A device

• for converting between angular values and the corresponding tangential values, comprising
• a protractor,
• means mounting a cylindrical micrometer housing adjacent said protractor, said housing having on a portion of its outer peripheral surface a set of axially spaced graduations,
• a reciprocable shaft projecting slidably from one end of said housing and extending over, and parallel to, a portion of at least one quadrant of said protractor,
• said housing having a sleeve rotatably mounted thereon and operatively connected to said shaft to shift said shaft selectively in and out of said one end of said housing,
• a pin carried by said shaft and having a pointed end overlying said protractor for movement by said shaft between a first limit position in which the pointed end of said pin registers with a line on said protractor corresponding to a zero angle on the protractor, and a second limit position in which said pointed end registers with a line denoting an angle of 45.degree. on the protractor,
• said graduations on said housing being calibrated to represent the corresponding tangential values of the angles included on the protractor between said zero and 45.degree. designations,
• said sleeve being mounted to reciprocate axially on said housing, when rotated in opposite directions thereon,
• said sleeve being in one of its limit positions when the pointed end of said pin registers with the zero angle on said protractor, and is in the other of its limit positions when said pointed end registers with the 45.degree. angle on said protractor,
• one end of said sleeve registering with a graduation denoted as zero on said housing, when the sleeve is in said one, position, and registering with a graduation denoted as "1" on said housing, when said sleeve is in its other limit position,
• a rod having a bifurcated end pivotally connected to said shaft by said pin, and
• means supporting said rod intermediate its ends for pivotal movement about the center point of said protractor, and for sliding movement at right angles to axis of its pivotal movement, whereby when said shaft is reciprocated the angular position of said rod about said center point will have its corresponding tangential value represented by the graduation on said housing then in registry with said one end of said sleeve.