US3883735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line tracer
Assignee: Westinghouse Canada Inc
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Filing: 1973-12-26
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Granted: 1975-05-13
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Expires: 1993-12-26
Abstract
Abstract A line tracing system having provision for memory function to enable it to cross inadvertent or intentional gaps in the line and maintain the same direction. In addition, the system can identify the end of a line and stop or reverse as desired. By utilizing co-ordinate direction, information from the drawing and from the tracing head a gating signal is produced which is continuously directed in the forward direction in which tracing is to take place.
Inventors
- 👤 Francis P Murphy
- 👤 Robert E Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:12
CPC Classifications
B; B23; B23Q; B23Q35/00; B23Q35/04; B23Q35/08; B23Q35/12; B23Q35/127; B23Q35/128
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
147 words
A circular scanning line tracer including optical means to scan an illuminated pattern and produce a train of pulses in accordance with the front and rear crossing of the line by the scan, a pair of sinusoidal reference signals phase related to the rotational position of the scan, means comprising gating means for selecting from said train of pulses those pulses indicative of the front crossing of the line by the scan, means to utilize the pulses so selected to sample said sinusoidal reference signals and produce co-ordinate signals representative of the direction of the line relative to the rotational position of the scan, means to combine said coordinate signals with said sinusoidal signals to produce a directional sinusoid of constant amplitude with phase representative of the direction of the line and means to derive from said directional sinusoid, a gating signal to control said gating means.
Claim 2
Dependent Claim
147 words
A circular scanning line tracer including optical means to scan an illuminated pattern and produce a train of pulses in accordance with the front and rear crossing of the line by the scan, a pair of sinusoidal reference signals phase related to the rotational position of the scan, means comprising gating means for selecting from said train of pulses those pulses indicative of the front crossing of the line by the scan, means to utilize the pulses so selected to sample said sinusoidal reference signals and produce co-ordinate signals representative of the direction of the line relative to the rotational position of the scan, means to combine said coordinate signals with said sinusoidal signals to produce a directional sinusoid of constant amplitude with phase representative of the direction of the line and means to derive from said directional sinusoid, a gating signal to control said gating means.
Claim 3
Dependent Claim
26 words
A circular scanning line tracer as claimed in claim 1 wherein said pair of sinusoidal reference signals comprise a sine wave and a cosine wave signal.
Claim 4
Dependent Claim
45 words
A circular scanning line tracer as claimed in claim 1 wherein said gating signal continues to be produced in the same phase with reference to the rotational position of the scan even in the absences of one or more pulses from said train of pulses.
Claim 5
Dependent Claim
24 words
A circular scanning line tracer as claimed in claim 3 wherein said gating signal continues to be produced for a selectable period of time.
Claim 6
Dependent Claim
38 words
A circular scanning line tracer as claimed in claim 1 including means to detect the end of a line and means to stop further tracing a predetermined period of time after detection of the end of the line.
Claim 7
Dependent Claim
73 words
A circular scanning line tracer as claimed in claim 1 having a first gating signal derived from said selected pulses and a second gating signal derived from said directional sinusoid and means to utilize said first gating signal to enable selection of pulses from said train of pulses when a line has been scanned and to utilize said second gating signal to enable selection of pulses after the absence of a scanned line.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |