Geometrical instruments – Distance measuring – Process
Patent
1990-04-30
1991-11-12
Cuchlinski, Jr., William A.
Geometrical instruments
Distance measuring
Process
33758, 33503, 156574, 156361, G01B 310, G01B 2100, B32B 3100
Patent
active
050636855
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method and a device for applying a tape to a substrate which is provided on a coordinate positioning machine (e.g. a coordinate measuring machine or machine tool). It may be used to apply a metrological scale which is in the form of a tape to such a machine. Typically, the coordinate positioning machine will have at least two parts movable relative to each other along an axis; the scale is affixed to one of the parts, and used in conjunction with a read head (attached to the other of the parts) to measure the relative movement of the two parts. The read head projects light onto the scale, and, from the light passed on by the scale determines the magnitude of relative movement of the two members along the axis.
SUMMARY OF THE INVENTION
In order to obtain high accuracy measurements of the relative movement of the two parts, it is desirable to apply the tape to one of the parts so that it retains a precise pre-determined alignment with the read head along the entire extent of movement of the read head. Any misalignment of the tape relative to the path of the read head will inevitably result in reduced accuracy measurement readings. The present invention attempts to overcome the difficulty of misalignment of the tape by providing a method and apparatus of applying a tape to a substrate according to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of the invention will be described with reference to the accompanying drawings wherein:
FIG. 1 is an isometric view of a first embodiment of a device according to the present invention,
FIG. 2 is a plan view showing the device in FIG. 1 mounted on a co-ordinate measuring machine or machine tool,
FIG. 3 is a horizontal section on the line III--III in FIG. 1,
FIG. 4 is a horizontal section on the line IV--IV in FIG. 1,
FIG. 5 shows part of a tape scale which is to be applied to the machine,
FIGS. 6 and 7 are isometric views showing the positioning of the scale in the device prior to applying it to the machine,
FIG. 8 is an enlarged view of part of FIG. 7,
FIG. 9 is an isometric view of a second, and preferred, embodiment of a device according to the present invention,
FIG. 10 is a section on the line X--X in FIG. 9,
FIG. 11 is a section on the line XI--XI in FIG. 9, and
FIG. 12 is an isometric view showing the application of a scale to a substrate using the device of FIGS. 9 to 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIG. 2 there is shown a portion of a co-ordinate measuring machine or machine tool, comprising a relatively fixed part 50 having a guideway 52 along which a movable part 54 is slideable. (The guideway thus defines the axis of relative movement of the two members). For example, the movable parts 54 may be a carriage or gantry of the machine, while the relatively fixed part 50 may be the bed of the machine or another carriage or gantry. It is common in such machines to provide a periodically marked metrological scale 26 on the fixed part 50 (which thus provides a substrate for supporting the scale), and a readhead on the movable part 54, so as to measure the relative position of the two parts. The inverse arrangement, with the scale on a movable part (which would then provide the substrate) and the readhead on a relatively fixed part, is also quite common, and the present invention is equally applicable to such an arrangement.
The plane in which the substrate lies (and thus in which the scale is supported) may be defined as the x-y plane; the x-axis extends in the direction of the length of the scale (which is ideally parallel to the guideway 52), and the y-axis in the direction of extension of the lines on the scale. A z-axis is defined as extending parallel to the surface normal of the x-y plane. This notation will be adhered to in all examples shown in the present application.
Our International Patent Specifications Nos. WO 88/00331 and WO 88/00332 show examples of such scales and readheads, in which the scale is in the form of a flexible tape
REFERENCES:
patent: 2742705 (1956-04-01), Gelardi
patent: 3775219 (1973-11-01), Karlson et al.
patent: 3810805 (1974-05-01), Goldsworthy et al.
patent: 4333238 (1982-06-01), McMurtry
patent: 4702013 (1987-10-01), McMurtry
patent: 4777818 (1988-10-01), McMurtry
patent: 4781782 (1988-11-01), Luhman et al.
patent: 4782598 (1988-11-01), Guarini
patent: 4877193 (1989-10-01), Vaniglia
patent: 4884889 (1989-12-01), Beckwith, Jr.
patent: 4936023 (1990-06-01), Pechak
Henning Brian C. R.
Lummes Stephen E.
McMurtry David R.
Morrison Robert B.
Cuchlinski Jr. William A.
Fulton C. W.
Renishaw plc
LandOfFree
Tape scale applicator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tape scale applicator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tape scale applicator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1005181