Optics: measuring and testing – By alignment in lateral direction – With light detector
Reexamination Certificate
1999-05-28
2001-10-09
Evans, F. L. (Department: 2877)
Optics: measuring and testing
By alignment in lateral direction
With light detector
C356S401000
Reexamination Certificate
active
06301007
ABSTRACT:
TECHNICAL FIELD
This invention relates to an optical machine tool locator and a method of locating a machine tool.
BACKGROUND ART
It is necessary to know the machine tool tip radius and the position of the machine tool edge relative to the manufacturing machine axis to accurately machine parts within close tolerances. Presently this is generally done using electronic touch probes which locate the tool at the machine in only two dimensions. Touch probe systems cannot provide visual feedback useful for measuring the shape of the cutting tool edge and detecting tool wear and condition. Touch probes are also subject to stiction, dirt and wear.
Visual systems such as optical comparators have been used to measure the shape of the machine tool cutting edge or to detect cutting tool wear. Generally these visual systems are remote from the manufacturing machine and thus are not aligned to reference points that have precise relationships to the machine axes.
Therefore, there is still a need for a measuring and positioning system which can be used at the machine: to set tools accurately without touching the tool or the part; to measure tool radius at the machine; to measure machine tool wear during machining; and to detect and accurately reposition damaged or worn out machine tools.
It is an object of this invention to provide a method and apparatus for measuring and positioning tools for machining.
It is another object of this invention to provide a method and apparatus for measuring machine tool radius and wear.
It is a further object of this invention to provide a machine tool locator which is aligned to a reference point which has a precise, known spatial relationship to the machine axes.
It is yet another object of this invention to provide a method and apparatus for measuring machine tool radius and wear without contact with the machine tool.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. The claims are intended to cover all changes and modifications within the spirit and scope thereof.
DISCLOSURE OF INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, there has been invented an apparatus and method for accurately measuring and positioning machine tools within small tolerances on manufacturing machines such as machine shop lathes.
An autocollimator with projection and reference reticles is positioned so that it is focused through lenses as needed upon a reference tooling ball. The reference tooling ball is located at an exactly known distance from the axis and faceplate of the manufacturing machine.
A digital camera is attached to the viewing end of the autocollimator to receive images reflected back from the reference tooling ball or to view the edges of the machine tool.
A marker and measure generator connected to the digital camera receives digital signals from the camera and can overlay markers, lines and circles on the images before relaying the images to a monitor. Images of the reference reticle, images of the projection reticle reflected from the reference tooling ball, or images of the machine tool tip can be displayed. Fine line crosses generated by the marker and measure generator are overlaid on the monitor screen and positioned over the reference reticles with the measure and marker generator by use of keyboard controls for aligning the tool tip. The marker and measure generator can also be used to measure distances on the monitor screen images, and to measure the size and shape of the machine tool tip.
To align a tool tip, the slides of the three-axis mount holding the autocollimator are moved until the image of the projection reticle that has been reflected from the reference tooling ball is completely aligned on the monitor screen with the image of the reference reticle. The machine tool is then substituted for the reference tooling ball. An image of the reference reticle and the machine tool are displayed on the monitor screen. The machine tool is moved until the image of the machine tool edge is aligned with the reference reticle, meaning that the machine tool edge is also aligned with the known position of the reference tooling ball and therefore with respect to the manufacturing machine axes. At least two viewing directions are provided so the machine tool can be aligned in three dimensions.
To measure the size and shape of the machine tool tip, three or more markers which are generated by the marker and measure generator are aligned with the outer diameter of the image of the machine tool tip displayed on the monitor screen, then a circle which passes through the markers is generated and related to the actual radius of the machine tool tip.
After using these procedures for aligning a machine tool tip and for measuring the shape of a machine tool tip, the actual position and dimensions of the machine tool tip can then be entered into a CNC controller program for generating an extremely accurate tool path that takes into account position and size of the machine tool tip.
By using magnified backlit images of the machine tool tip, the invention also can be used to measure machine tool tip wear.
A PC can be used in place of the marker and measure generator and also can be used to provide a historical record of the machine tool tip wear and the machine tool setting operation.
REFERENCES:
patent: 3736402 (1973-05-01), Mefferd et al.
patent: 4451892 (1984-05-01), McMurtry
patent: 4653360 (1987-03-01), Compton
patent: 4817007 (1989-03-01), New
patent: 4990840 (1991-02-01), Migda
patent: 5024527 (1991-06-01), Harrison
patent: 5054929 (1991-10-01), Dey
patent: 5069528 (1991-12-01), Dey
patent: 5072399 (1991-12-01), Laws et al.
patent: 5193314 (1993-03-01), Wormley et al.
patent: 5255199 (1993-10-01), Barkman et al.
patent: 5387061 (1995-02-01), Barkman et al.
patent: 5461472 (1995-10-01), Harvey et al.
patent: 5691540 (1997-11-01), Halle et al.
patent: 3238691 (1984-04-01), None
Gill Timothy J.
Hanlon John A.
Bennett Gemma Morrison
Evans F. L.
Smith Zabrew
The Regents of the University of California
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