Measuring and testing – Instrument proving or calibrating – Volume of flow – speed of flow – volume rate of flow – or mass...
Patent
1986-06-25
1988-10-18
Noland, Tom
Measuring and testing
Instrument proving or calibrating
Volume of flow, speed of flow, volume rate of flow, or mass...
73 1J, 33503, G01B 2100, G01B 700, G01D 1800
Patent
active
047778180
DESCRIPTION:
BRIEF SUMMARY
This invention is for an improvement relating to coordinate positioning apparatus and, more specifically, for a method of and device for checking the accuracy of such apparatus.
BACKGROUND OF THE INVENTION
It is usually required to determine the accuracy of coordinate positioning apparatus, for example coordinate measuring machines, and manual methods exist for doing so. For example, it is known to provide a test bar, operate the machine to measure the length of the bar in different locations of the bar in the coordinate field, and compare the possibly different results obtained at said different locations thereby to establish a measure of the accuracy of the apparatus. The bar itself has to be placed manually into the respective said positions, use being made of a frame or the line to support the bar in those positions. It is an object of this invention to provide a method of and device for checking coordinate positioning apparatus automatically or substantially automatically.
SUMMARY OF THE INVENTION
According to this invention there is provided a method of checking the accuracy of orthogonal coordinate positioning apparatus, the apparatus comprising a support, a head supported for three-dimensional movement relative to the support, and continually operative measuring means for measuring the position of the head in terms of three orthogonal coordinates; the method comprising providing a test bar, universally pivotally connecting the bar at its one end to the support and at its other end to the head, automatically and sequentially moving the head through a plurality of test locations situated about the connection of the bar to the support, the bar undergoing a corresponding angular movement by virtue of its connection to the head, and at each said location measuring the coordinate position of the head as determined by the length of the bar between said ends thereof.
The method according to this invention avoids the need to position the test bar manually and in this way reduces or avoids the difficulties of the known method.
Also according to this invention there is provided a device for checking coordinate positioning apparatus having a support, a head supported for three-dimensional movement relative to the support, and means for measuring the coordinate position of the head; the device comprising a bar, a mounting removeably securable to the support of the apparatus, first pivot means for supporting the bar at one end thereof for universal pivotal motion on said mounting, second pivot means provided at the other end of the bar and adapted for establishing a universal pivotal connection between said other end of the bar and the head of the machine, and means for producing a signal responsive to the head attaining a predetermined location in the coordinate field of the machine.
The device is intended for carrying out the method according to this invention, and said signal is used to effect the reading of said continually operative means for measuring the coordinate position of the head.
BRIEF DESCRIPTION OF DRAWINGS
In the accompanying drawings:
FIG. 1 is an elevation of a coordinate measuring machine and a checking device therefor.
FIG. 2 is an enlarged detail of FIG. 1
FIG. 3 is a view in the direction of the arrow III in FIG. 2.
FIG. 4 is a view similar to FIG. 1 in diagrammatic form.
FIG. 5 is a plan view of FIG. 4.
FIG. 6 is a flow diagram of a computer program.
DESCRIPTION OF PREFERRED EMBODIMENT
A preferred embodiment of the invention will now be described, by way of example, with reference to the above drawings. Refering to FIG. 1, the coordinate measuring machine, denoted 10, comprises a support or table 11 and a head 12 supported by slides 13,14,15 for three-dimensional movement in the directions X,Y,Z of the orthogonal coordinate system. The Y,Y,Z coordinates of the movement are measurable by continually operative opto-electronic scales 16,17,18 and cooperating counters 19,20,21. The slide movement is producable by motors eg. a motor 22 acting on the slide 13 through a belt 23. The
REFERENCES:
patent: 4168576 (1979-09-01), McMurtry
patent: 4435905 (1984-03-01), Bryan
patent: 4437151 (1984-03-01), Hurt et al.
"Measuring Up: Coordinate Measuring Machine Survey"; Tooling and Production; vol. 49, No. 2, May 1983; pp. 40-46 (p. 47 missing).
Noland Tom
Renishaw plc
LandOfFree
Coordinate positioning apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coordinate positioning apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coordinate positioning apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1187775