Apparatus for measuring objects

• US 8,533,970 B2
• Filed: 04/06/2011
• Issued: 09/17/2013
• Est. Priority Date: 04/09/2010
• Status: Active Grant

• Current Assignee: STOTZ Feinmesstechnik GmbH
• Original Assignee: STOTZ Feinmesstechnik GmbH
• Inventors: Stamenkovic, Milan
• Primary Examiner(s): FULTON, CHRISTOPHER W
• Application Number:
  US13/081,247
• Publication Number:
  US 20110247228A1
• Time in Patent Office: 895 Days
• Field of Search: 335/03, 335/56, 335/58, 335/59, 335/61
• US Class Current: 33/559
• CPC Class Codes: G01B 13/00 Measuring arrangements characterised by the use of fluids
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor

Abstract

An apparatus for measuring objects, in particular to a coordinate measuring unit, is provided. The unit has a probe which is movable relative to an object to be measured by means of an actuator to sample the surface of the object in a contacting manner, wherein a sampling body, whose front end is designed as a measuring tip for a contact with the object is supported at the probe. The relative position of the measuring tip with respect to the probe is determined. The sampling body is supported at the probe with movement play along at least one direction. A change in the inclination of the sampling body relative to the probe, or vice versa, can be detected via a measurement of a test parameter.

Claims

1. An apparatus for measuring objects, the apparatus having a probe which is movable relative to an object to be measured by means of an actuator to sample the surface of the object in a contacting manner,

wherein a sampling body whose front end is designed as a measuring tip for a contact with the object is supported at the probe and means are provided to determine the relative position of the measuring tip with respect to the probe,

wherein the sampling body is supported at the probe with movement play along at least one direction;

and

wherein means are provided by which a movement of the sampling body relative to the probe, or vice versa, can be detected via a measurement of a test parameter, wherein the means for detecting a movement, in particular a change in inclination, include at least one pneumatic measuring nozzle which opens into a cut-out of the sampling body.

2. An apparatus in accordance with claim 1, wherein said apparatus is a coordinate measuring unit.

3. An apparatus in accordance with claim 1, wherein said sampling body is an elongate sampling body.

4. An apparatus in accordance with claim 1, wherein said movement play along at least one direction includes a changeable inclination.

5. An apparatus in accordance with claim 4, wherein a movement of the sampling body relative to the probe includes a change in the inclination.

6. An apparatus in accordance with claim 1, wherein the test parameter is a spacing of the sampling body from a reference point.

7. An apparatus in accordance with claim 1, wherein the sampling body is supported in a mount of the probe.

8. An apparatus in accordance with claim 1, wherein measuring apparatus are provided in the probe to detect the position of the sampling body in at least one measurement plane extending transversely to a longitudinal axis of the sampling body and wherein measuring apparatus are provided in the probe which are designed to detect the position of the sampling body in two different measurement planes extend transversely to a longitudinal axis of the sampling body.

9. An apparatus in accordance with claim 8, wherein said measuring apparatus are able to continuously detect the position of the sampling body.

10. An apparatus in accordance with claim 1, wherein the sampling body has a cylindrical-shaped, or a parallelepiped-shaped, bearing section which is received with movement play in a cut-out of the probe, with the sampling body being inserted into the cut-out from above.

11. An apparatus in accordance with claim 10, wherein said cut-out is open at one side.

12. An apparatus in accordance with claim 1, wherein two respective pneumatic measuring nozzles arranged offset from one another about the longitudinal axis are provided in at least one measurement plane extend transversely to a longitudinal axis of the sampling body, and/or wherein two respective pneumatic measuring nozzles arranged offset from one another about the longitudinal axis are provided in two measurement planes spaced apart from one another and extend transversely to a longitudinal axis of the sampling body.

13. An apparatus in accordance with claim 1, wherein at least one pair of mutually opposite pneumatic measuring nozzles, arranged offset from one another about the longitudinal axis, are provided or wherein two pairs of mutually opposite pneumatic measuring nozzles are arranged offset from one another.

14. An apparatus in accordance with claim 1, wherein the means for detecting a movement include an arrangement of a pneumatic measuring nozzle opening into the cut-out and of a support element projecting from an inner wall of the mount.

15. An apparatus in accordance with claim 14, wherein the means for detecting a movement detects a change in inclination.

16. An apparatus in accordance with claim 1, wherein a controllable compressed air supply is associated with each measuring nozzle.

17. An apparatus in accordance with claim 1, wherein a pneumo-electric converter configured to generate a measured signal dependent on the position of the sampling body in the cut-out, in dependence on an air pressure of the measuring nozzle, is associated with each measuring nozzle.

18. An apparatus in accordance with claim 17, wherein an electronic evaluation unit is provided which determines the position of the sampling body relative to the probe with reference to the generated measured signals.

19. An apparatus in accordance with claim 18, wherein said electronic evaluation unit continuously determines the position of the sampling body relative to the probe.

20. An apparatus in accordance with claim 18, wherein said evaluation unit determines the inclination of the sampling body relative to the probe.

21. An apparatus in accordance with claim 1, wherein the sampling body is supported in a floating manner on a flow of air in a mount of the sampling head during the operation of the measurement apparatus.

22. An apparatus in accordance with claim 21, wherein at least one upwardly directed air outlet nozzle is provided in the mount for the floating support of the sampling body.

23. An apparatus in accordance with claim 22, wherein the air outlet nozzle is designed as a pneumatic measuring nozzle which is designed to determine the height of the sampling body supported in a floating manner in the mount.

24. An apparatus for measuring objects, the apparatus having a probe which is movable relative to an object to be measured by means of an actuator to sample the surface of the object in a contacting manner,

wherein a sampling body whose front end is designed as a measuring tip for a contact with the object is supported at the probe and means are provided to determine the relative position of the measuring tip with respect to the probe,

wherein the sampling body is supported at the probe with movement play along at least one direction;

and

wherein means are provided by which a movement of the sampling body relative to the probe, or vice versa, can be detected via a measurement of a test parameter,

wherein at least one pneumatic measuring nozzle opening into a cut-out of the sampling body is provided in each of at least two measurement planes spaced apart from one another with respect to a longitudinal axis, and

a support element projecting from an inner wall of the cut-out is provided between the two measurement planes.