Geometrical instruments – Gauge – Pivoted probes
Patent
1989-08-01
1991-09-17
Will, Thomas B.
Geometrical instruments
Gauge
Pivoted probes
33561, G01B 520, G01B 728
Patent
active
050481940
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to probes used for position sensing or measurement, in position determining apparatus such as co-ordinate measuring machines, machine tools and inspection robots.
DESCRIPTION OF PRIOR ART
It is known in such machines to mount a probe in a quill or spindle of the machine for movement in three dimensions, X,Y,Z. The machine has means for measuring the X,Y and Z co-ordinates of the probe, such as a scale and read head for each of these co-ordinate directions.
Two types of such probe are in common use. One is a trigger probe, which produces a trigger signal upon attaining a pre-determined relationship with a workpiece surface (such as contact of a stylus of the probe with the workpiece surface). This trigger signal is used to latch or freeze the output from the scales and read heads of the machine, and to cause a computer or numerical control which controls the operation of the machine to read the X,Y and Z co-ordinates relating to the position on the workpiece surface thus sensed. Examples of such probes can be seen in UK Patent Application GB 2,006,435 A (Renishaw), International Patent Application WO 86/03829 (Renishaw), and U.S. Pat. No. 4,177,568 (Zeiss).
The other known kind of probe is a measurement probe, producing an analogue or digital output proportional to displacement of a stylus of the probe in the X,Y and Z directions. Such a probe is particularly useful for scanning the contour of a workpiece surface, as opposed to measuring specific points on the workpiece surface to gauge the dimensions of the workpiece. Examples can be seen in U.S. Pat. No. 3,945,124 (Leitz), GB 1,429,973 (Zeiss), GB 1,551,218 (Rolls-Royce and Renishaw) and EP 0,239,337 (Renishaw).
SUMMARY OF THE INVENTION
In broad outline, one aspect of the present invention provides a combination of a trigger probe and a measurement probe.
In a second aspect of the invention, the present application describes novel forms of measurement probe, useable with or without combination with a trigger sensor.
In a third aspect, the invention relates to various novel methods of using a probe.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described with reference to the accompanying drawings, wherein:
FIG. 1 is a vertical cross section of a probe,
FIG. 2 is an isometric diagram of part of the probe,
FIG. 3 is a block diagram showing how sensors in the probe are connected in a co-ordinate measuring machine or machine tool,
FIGS. 4 and 5 are vertical and horizontal sections of part of a modified probe, and
FIG. 6 is a vertical section of part of a further modified probe.
DESCRIPTION OF PREFERRED EMBODIMENTS
Measurement Probe Arrangement
Referring firstly to FIG. 1, the probe has an upper housing 10 which can be inserted in the quill or spindle of a co-ordinate measuring machine, inspection robot or machine tool, so as to be movable in three dimensions X,Y,Z. The probe comprises three spring parallelogram arrangements 12X, 12Y, 12Z arranged in series between the relatively fixed housing 10 and a movable workpiece-contacting stylus 14. Each of the spring parallelograms permits translational movement of the stylus 14 in a respective one of the directions X,Y,Z. Thus, the spring parallelogram 12Z allows for Z axis movement of a connecting member 16 arranged between the parallelograms 12Z and 12Y; the spring parallelogram 12Y provides for Y axis movement of a lower housing 18 relative to the connecting member 16; and the spring parallelogram 12X provides for X axis movement of a stylus holder 20 relative to the housing 18, the stylus 14 being secured in the stylus holder 20. The three spring parallelograms are substantially identical, except that they are of course orientated at 90.degree. to each other, and the arrangement 12Y is inverted with respect to the arrangement 12X so that both fit inside the lower housing 18.
The spring parallelogram arrangement 12X will be described with reference to both FIGS. 1 and 2. An inner plate 22X, which carries the stylu
REFERENCES:
patent: 3869799 (1975-03-01), Neuer et al.
patent: 3945124 (1976-03-01), Jacoby et al.
patent: 4084323 (1978-04-01), McMurtry
patent: 4153998 (1979-05-01), McMurtry
patent: 4177568 (1979-12-01), Werner et al.
patent: 4333238 (1982-06-01), McMurtry
patent: 4364180 (1982-12-01), Willhelm
patent: 4513507 (1985-04-01), Laskowski
patent: 4523383 (1985-06-01), Rogers et al.
patent: 4563823 (1986-01-01), Klingler et al.
patent: 4621434 (1986-11-01), Hirschmann
patent: 4716656 (1988-01-01), Maddock et al.
patent: 4752166 (1988-06-01), Lehmkuhl
patent: 4769919 (1988-09-01), Lloyd et al.
patent: 4882848 (1989-11-01), Breyer et al.
Renishaw plc
Will Thomas B.
LandOfFree
Position sensing probe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Position sensing probe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Position sensing probe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1907104