Compensation of errors in incremental measuring or positioning instruments
AssigneeDr. Johannes Heidenhain GmbH
InventorAlfons Ernst
Life of this patent
Estimating the term…
Abstract
A method and apparatus for the compensation of guiding errors in an incremental measuring instrument used in conjunction with machine tools or measuring machines is disclosed in which the measuring graduation is corrected in its mounting position in accordance with the error values of the machine. A preferred embodiment of this method is disclosed in which the error compensation is accomplished by the application of equal longitudinal compression or extension forces to the ends of the measuring graduation.
Claims15
A digital electrical measuring instrument for measuring or adjusting the relative position of two objects which compensates for the guiding errors of the two objects, comprising:
- a longitudinally extending, bending resistance hollow body having means for attachment to one of the objects;
- a longitudinally extending, bending resistant measuring scale within the hollow body, fastened to the hollow body by a highly elastic layer interposed between only a single surface of the scale and the adjacent surface of the hollow body;
- a scanning head within the hollow body, having a connecting means extending out of the hollow body for attachment to the other object;
- and
- adjustable first and second force-generating means mounted at the longitudinal ends of the hollow body for applying forces, acting in opposite directions, to the longitudinal ends of the measuring scale, whereby forces of equal magnitude, acting in opposite directions, may be applied to the longitudinal ends to adjust the length of the scale to compensate for the guiding errors of the objects.
In a digital electrical measuring instrument for measuring or adjusting the relative position of two objects including a longitudinally extending, bending resistant graduated measuring scale disposed within and fastened to a hollow body which is attachable to one of the objects, the improvement comprising:
- the fastening of the measuring scale to the hollow body solely by a highly elastic layer interposed between only a single surface of the scale and the adjacent surface of the hollow body, so that the scale does not have any direct contact with the hollow body;
- and, adjustable first and second force-generating means mounted at the longitudinal ends of the hollow body for applying forces to the longitudinal ends of the measuring scale, whereby forces of equal magnitude, acting in opposite directions, may be applied to the longitudinal ends to adjust the length of the measuring scale to compensate for the guiding errors of the objects.
Dependencies are inferred from the claim text.