Geometrical instruments – Area integrators – Electrical
Patent
1987-10-09
1989-03-28
Martin, Jr., William D.
Geometrical instruments
Area integrators
Electrical
33 1M, 33503, G01C 1506
Patent
active
048152137
ABSTRACT:
In a coordinate measuring machine, apparatus for compensating the sensing means for determining the position of a probe for changes in temperature, where the machine base and the support column for the probe have differing coefficients of thermal expansion. In a preferred embodiment, the apparatus of this invention is used to prevent "zero shift" in the Z-direction for a Z-rail. The compensating apparatus is associated either with the support column or Z-rail. The apparatus offsets the greater expansion of the machine component having the greater coefficient of thermal expansion. Typically, the position sensing means for the Z-rail includes an encoder and a scale. In one embodiment, either the encoder or the scale is secured to a mount which is affixed to the column. One element of the mount which extends upwardly from the support column has a coefficient of thermal expansion which is substantially less than that of the aluminum of which the column is composed. In another embodiment of this invention, the encoder the scale is secured to a lower end of a rod depending downwardly from the support column. In this alternative embodiment, the rod is composed of a material having a coefficient of thermal expansion substantially greater than that of the component of the support column, which is especially aluminum. In a third embodiment, two supports can be used, one having a coefficient of thermal expansion substantially greater than aluminum and another having a coefficient of thermal expansion substantially less than aluminum. Similar apparatus also is used to prevent "zero shift" in the X and Y directions.
REFERENCES:
patent: 2664787 (1954-01-01), Plimmer
patent: 3045510 (1962-07-01), Brainard
patent: 3212194 (1965-10-01), Brault
McCabe William J.
Pesikov Vitaly I.
Brown & Sharpe Manufacturing Co.
Martin, Jr. William D.
LandOfFree
Apparatus for temperature compensation of sensing means of a mac does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for temperature compensation of sensing means of a mac, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for temperature compensation of sensing means of a mac will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1650334