Measuring arrangement
AssigneeDr. Johannes Heidenhain GmbH
InventorsAlfons Ernst, Alfred Reichl
Life of this patent
Estimating the term…
Abstract
A laser interferometer is disclosed in which the measuring path is enclosed in an elongated hollow body which has a flexible slot along one side through which extends the entrainment means for the movable reflector enclosed within the hollow body. This hollow body is maintained under a vacuum, with the area around the flexible slot being filled with a fluid to help maintain the vacuum. This fluid may be highly viscous oil or a magnetic fluid which is maintained by the magnetic field of permanent magnets.
Claims19
A measuring instrument for measuring the relative position of an object, comprising:
- a measuring element movable along a path;
- a supporting means for connecting the movable measuring element to the object whose position is to be measured;
- an elongated hollow body enclosing the area around the measuring element's path;
- an elongated slot formed in the hollow body, the slot extending along substantially the entire length of one longitudinally extending side of the hollow body, the slot being of sufficient size to permit the passage therethrough of the supporting means;
- flexible sealing members extending over the slot to seal the slot along its entire length and to accommodate the passage of the supporting means;
- and, a fluid which cooperates with the sealing members to seal the slot.
A measuring instrument for measuring the relative position of an object, comprising:
- a measuring element movable along a path;
- a supporting means for connecting the measuring element to the object whose position is to be measured;
- an elongated hollow body enclosing the area around the measuring element's path;
- an elongated slot formed in and extending along one longitudinally extending side of the hollow body, the slot being of sufficient size to permit the passage therethrough of the supporting means;
- a pair of mating, flexible, roof-shaped sealing lips extending over the slot to seal the slot along its entire length while permitting the passage therethrough of the supporting means;
- a groove formed between the sealing lips;
- a magnetic fluid disposed in the groove to seal said groove;
- and a means for generating a magnetic field to maintain the magnetic fluid in the groove.
Dependencies are inferred from the claim text.