Multiple arrangement of simultaneously used laser interferometers for trilaterational determination of the position of a movable point

摘要

The invention relates to a multiple arrangement of simultaneously used laser interferometers for trilaterational determination of the position of a movable point. In order to be able to use such a multiple arrangement to measure accurately the position of mating bores in a plane clamping plate, the laser interferometers are formed by in each case one basic module which is special for each interferometer and a measuring foot common to all the interferometers. The basic modules are set up in a fixed fashion at points whose position is known; they respectively contain on a rotating disc the necessary polarising beam splitter and the reference reflector. A plurality of rotating discs are arranged one above another on the measuring foot; specifically, they can be rotated separately but are all mounted about a common swivelling axis which is at right angles to the clamping plate in the centre of the point to be measured. Each of the measuring rotating discs carries on the outer circumference a measuring reflector which in terms of position is aligned as to its angular position with the associated measuring beam. By means of a suitable connection, of which the distance can be varied but which is secure against rotation, between each of the basic modules and the associated measuring rotating disc of the measuring foot, a permanent mutual alignment of the measuring beam and measuring reflector is maintained, with the result that the risk of beam interruption is avoided. Various possibilities are shown for such connections.