Height-measuring column and method for regulating a height-measuring column

#The present invention concerns a height-measuring column. The present invention concerns also the method for regulating a height-measuring column according to the invention.

#Height-measuring columns are measuring machines enabling the height of a point relative to a reference plane to be measured or the vertical distance between to measuring points to be calculated. The precision that is expected of such measuring machines is on the order of the micron.

#The main elements of a height-measuring column are generally:

#The invention will be better understood by reading the description of a preferred embodiment given by way of example and illustrated by the attached drawings, in which:

#FIG. 1 shows a simplified view of a height-measuring column.

#FIG. 2 shows a cross section of the base and of the seat of the supporting frame of a height-measuring column according to the invention.

#The preferred embodiment of the invention is a height-measuring column comprising a supporting frame 1 fastened on a base 3 perpendicular to the seat of this base 2, a carriage 4 moving on rails 10 along the supporting frame 1 thus defining the measuring axis. According to the applications, for example a probe tip 40 or a comparator (not represented) will be fastened on the carriage 4. The height-measuring column according to the preferred embodiment of the invention also comprises a measuring system in order to determine exactly the position of the carriage on the supporting frame and, by extension, to determine the coordinates on the position measuring axis, for example of the probe tip or of the comparator fastened to the carriage. The height-measuring column further comprises a driving mechanism controlling the movements of the carriage 4 along the supporting frame 1.

#The height-measuring column according to the preferred embodiment of the invention is designed to function on a plane reference surface 3 that can serve as zero point of the measuring axis, for example a marble or granite table.

#The supporting frame 1 of the height-measuring column is fastened to the base 2 by means of fastening elements. The function of the fastening elements is to ensure that the supporting frame 1 is held on the base 2 and that any mechanical play between these elements after assembly is avoided. In the preferred embodiment of the height-measuring column, these fastening elements are for example three fastening screws 7. The fastening screws 7 are inserted in the holes provided for this purpose under the base 2 of the height-measuring column, then screwed in the holes threaded at the bottom of the supporting frame 1 located opposite the holes of the base 2 when the base 2 and the supporting frame 1 are assembled. The fastening screws 7 are preferably fillister-head screws provided with washers 70 in order to spread the force exerted around the head on the base 2 during screwing. In order to avoid unscrewing after assembly of the fastening screws 7, the washers 70 will preferably be of the self-blocking type and can be secured by a drop of glue or of a screw locking product.