US3553456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reading of projected trace errors
Assignee: NAT RES DEV
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Filing: 1968-05-31
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Granted: 1971-01-05
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Expires: 1988-05-31
Abstract
Abstract A method and apparatus are disclosed in which a trace is optically projected on photocells incorporated in electrical circuitry providing a signal indicating the nearest photocell to a reference point on which the trace image is incident. The photocells can be positioned in line from the reference point and the image rotated around the point. The trace can be related to a standard profile, the distance of its image from the reference point representing divergences of workpiece profile from the standard. Provision can be made for providing a further signal indicating the direction of any such divergence. Provision can also be made for suppression of the signals except when they result from incidence on a photocell of light intensity greater than ambient intensity. In an alternative arrangement, the photocells comprise rings concentric on the reference point. The photocells may instead from a semicircular array, the image being doubled about the edge diameter thereof, or a pair of such arrays, the image being duplicated for projection on each array.
Inventors
- 👤 John Ronald Parks
- 👤 Ralph Eric Rengger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:12
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/24; G01B11/25
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
85 words
Apparatus for measuring displacement from a reference point of an optically projected image of a trace, the apparatus comprising a plurality of photocell elements arranged in line at different distances from the reference point, optical projection means for projecting the image on the photocell elements and including means for rotating the image about the reference point and electric circuit means including the photocell elements and arranged to afford an electric signal indicating the nearest element to the reference point on which the projected image falls.
Claim 2
Dependent Claim
85 words
Apparatus for measuring displacement from a reference point of an optically projected image of a trace, the apparatus comprising a plurality of photocell elements arranged in line at different distances from the reference point, optical projection means for projecting the image on the photocell elements and including means for rotating the image about the reference point and electric circuit means including the photocell elements and arranged to afford an electric signal indicating the nearest element to the reference point on which the projected image falls.
Claim 3
Dependent Claim
63 words
Apparatus as claimed in claim 1 in which the electric circuit means comprises a maximum selection circuit for detection of the largest photocell element output, memory devices responsive to the maximum selection circuit outputs, and a detector circuit for detection of the memory device actuated during one rotation of the trace which is associated with the photocell element nearest to the reference point.
Claim 4
Dependent Claim
99 words
Apparatus as claimed in claim 2 in which the photocell elements include a pair of sense elements spaced from The reference point at positions to have a projected trace image similar to but spaced from the first mentioned trace image and arranged to rotate therewith incident on them when the displacement of the first mentioned trace image from the reference point indicates a negative and a positive error respectively, and in which the electric circuit means comprises a maximum selection circuit, for detection of the larger sense element output, and memory devices responsive to the maximum selection circuit outputs.
Claim 5
Dependent Claim
66 words
Apparatus as claimed in claim 2 in which the photocell elements include balance photocell means arranged to produce an output greater than any other of the elements in response to ambient light and in the absence of the trace image, the output of the balance photocell means being made to prevent actuation of the memory devices unless the output is exceeded by that of another cell.
Claim 6
Dependent Claim
30 words
Apparatus as claimed in claim 2 having recording and/or indicating devices arranged to be responsive to the outputs of the memory devices once during each rotation of the trace image.
Claim 7
Dependent Claim
44 words
Apparatus as claimed in claim 1 in which the optical projection means includes a chopper and in which the electric circuit means includes an amplifier tuned to the chopping frequency for amplifying each photocell element output, and a detector for rectifying each amplifier output.
Claim 8
Dependent Claim
65 words
Apparatus as claimed in claim 1 in which the projected trace is related to a standard profile, the apparatus including a device for moving a member bearing the trace relative to a workpiece profile in such a way that differences of the workpiece profile from the standard profile cause the projected trace image to be spaced from the reference point in correspondence with said differences.
Claim 9
Dependent Claim
200 words
Apparatus for measuring differences between a workpiece profile and a standard profile, the apparatus comprising a device having a stylus, a member on which a trace for optical projection can be formed by movement of the stylus thereon, a feeler, means for mounting a standard element having a standard profile, and means linking the feeler, the stylus, the member and the mounting means so that as the feeler tracks the standard profile the stylus forms a trace related thereto on the member optical projection means for projecting an image of the trace on a plurality of photocell elements spaced at different distances from a reference point corresponding to the stylus position, and electric circuit means including the photocell elements arranged to produce a signal indicating the nearest element to the reference point on which the projected trace image is incident, whereby, on removal of the stylus and replacement of the standard profile by a workpiece profile, any signal produced during tracking of the workpiece profile by the feeler and projection of the trace image on the photocell elements will indicate displacement of the image from the reference point due to a difference of the workpiece profile from the standard profile.
Claim 10
Dependent Claim
200 words
Apparatus for measuring differences between a workpiece profile and a standard profile, the apparatus comprising a device having a stylus, a member on which a trace for optical projection can be formed by movement of the stylus thereon, a feeler, means for mounting a standard element having a standard profile, and means linking the feeler, the stylus, the member and the mounting means so that as the feeler tracks the standard profile the stylus forms a trace related thereto on the member optical projection means for projecting an image of the trace on a plurality of photocell elements spaced at different distances from a reference point corresponding to the stylus position, and electric circuit means including the photocell elements arranged to produce a signal indicating the nearest element to the reference point on which the projected trace image is incident, whereby, on removal of the stylus and replacement of the standard profile by a workpiece profile, any signal produced during tracking of the workpiece profile by the feeler and projection of the trace image on the photocell elements will indicate displacement of the image from the reference point due to a difference of the workpiece profile from the standard profile.
Claim 11
Independent Claim
129 words
A method of measuring differences between a workpiece profile and a standard profile, the method comprising the steps of relatively moving a feeler and the workpiece profile so that the feeler tracks the workpiece profile thereby effecting relative movement of a member, the member bearing a trace for optical projection, and a plurality of photocells on which an image of the trace is optically projected, the photocells being differently spaced from a reference point, the trace being such that the projected image thereof passes through the reference point except when the feeler is tracking a part of the workpiece profile which differs from the standard profile, and deriving from the photocells an electric signal indicating the photocell nearest the reference point on which the projected trace image is incident.
Claim 12
Independent Claim
129 words
A method of measuring differences between a workpiece profile and a standard profile, the method comprising the steps of relatively moving a feeler and the workpiece profile so that the feeler tracks the workpiece profile thereby effecting relative movement of a member, the member bearing a trace for optical projection, and a plurality of photocells on which an image of the trace is optically projected, the photocells being differently spaced from a reference point, the trace being such that the projected image thereof passes through the reference point except when the feeler is tracking a part of the workpiece profile which differs from the standard profile, and deriving from the photocells an electric signal indicating the photocell nearest the reference point on which the projected trace image is incident.
Claim 13
Dependent Claim
49 words
A method as claimed in claim 9 having the prior step of forming the trace by relatively moving the feeler and the standard profile to effect relative movement of the trace bearing member and a stylus in manner related to the relative movement of the feeler and the profile.
Claim 14
Dependent Claim
54 words
A method as claimed in claim 10 having the step of employing a device for effecting the relative movements of the standard profile and the feeler and of the workpiece member and the stylus also for effecting the relative movements of the workpiece profile and the feeler and of the member and the photocells.
Claim 15
Dependent Claim
45 words
A method as claimed in claim 9 having the step of rotating the projected image about the reference point, the photocells being arranged in a line extending therefrom, and using said electric signal for indicating said nearest photocell once during each rotation of the image.
Claim 16
Dependent Claim
95 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a plurality of elements located at positions differently spaced from said reference point, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; means for relatively rotating said projected image and said elements about said reference point; and electric circuit means including said elements arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image of radiation is incident.
Claim 17
Dependent Claim
95 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a plurality of elements located at positions differently spaced from said reference point, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; means for relatively rotating said projected image and said elements about said reference point; and electric circuit means including said elements arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image of radiation is incident.
Claim 18
Dependent Claim
79 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a plurality of concentric ring-shaped elements centered on said reference point, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
Claim 19
Dependent Claim
79 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a plurality of concentric ring-shaped elements centered on said reference point, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
Claim 20
Dependent Claim
95 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a semicircular array of concentric half-ring shaped elements centered on said reference point, each element being adapted to produce an electric output in response to incidence of said projected image of radiation thereon; means for doubling said projected image about the edge diameter of the array; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
Claim 21
Dependent Claim
95 words
Apparatus for measuring displacement from a reference point of a radiantly projected image of a trace, said apparatus comprising: a semicircular array of concentric half-ring shaped elements centered on said reference point, each element being adapted to produce an electric output in response to incidence of said projected image of radiation thereon; means for doubling said projected image about the edge diameter of the array; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
Claim 22
Dependent Claim
92 words
Apparatus for measuring displacement from a reference point of a trace, said apparatus comprising: a pair of semicircular arrays of concentric half-ring shaped elements centered on a reference point; means for radiantly projecting an image of said trace on each set of arrays, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
Claim 23
Dependent Claim
92 words
Apparatus for measuring displacement from a reference point of a trace, said apparatus comprising: a pair of semicircular arrays of concentric half-ring shaped elements centered on a reference point; means for radiantly projecting an image of said trace on each set of arrays, each element being adapted to produce an electric output in response to incidence of said projected image radiation thereon; and electric circuit means including said elements and arranged to afford an electric signal indicating the nearest element to said reference point on which said projected image radiation is incident.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |