US3854133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-magnetic distance measuring apparatus
Assignee: South African Inventions Development Corp
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Filing: 1973-05-29
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Granted: 1974-12-10
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Expires: 1993-05-29
Abstract
Abstract In an electro-magnetic distance measuring instrument of the type in which a distance between two points is inferred from a knowledge of the transit time of an electro-magnetic wave by means of a series of phase measurements taken with waves of decreasing effective frequency, apparatus for automatically deriving a final distance from such a series of measurements. These phase measurements have two digits, are subject to errors and are taken with waves having effective frequencies related by powers of ten. The apparatus of the invention operates sequentially on measurements due to waves of decreasing effective frequency by adding a number which may be either four or five to, and subtracting the magnitude of the tens digit of the preceding measurement from a new measurement. This operation corrects the tens digit of the new measurement for any error which may have occurred during measuring, so that it can be used as one of the digits in the final result.
Inventors
- 👤 P Cabion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:08
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/32; G01S13/36
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
146 words
A device for processing phase measurements obtained from electro-magnetic distance measuring apparatus yielding successive phase difference measurements each having one digit with the same significance as the current most significant digit in a partial measure of the distance and one digit of greater significance than that digit to indicate the final distance, comprising means to accept measurements from the measuring apparatus, means to accumulate those measurements and after the first measurement to add in a modulo corresponding with the number of digits in a phase measurement and at the weight of the current most significant digit in the partial measure a correcting quantity to each measurement to allow for error in the measurement, means to control the accumulating means so that correcting quantity is a predetermined quantity minus the current most significant digit in the partial measure of distance, and means to indicate the final distance.
Claim 2
Independent Claim
146 words
A device for processing phase measurements obtained from electro-magnetic distance measuring apparatus yielding successive phase difference measurements each having one digit with the same significance as the current most significant digit in a partial measure of the distance and one digit of greater significance than that digit to indicate the final distance, comprising means to accept measurements from the measuring apparatus, means to accumulate those measurements and after the first measurement to add in a modulo corresponding with the number of digits in a phase measurement and at the weight of the current most significant digit in the partial measure a correcting quantity to each measurement to allow for error in the measurement, means to control the accumulating means so that correcting quantity is a predetermined quantity minus the current most significant digit in the partial measure of distance, and means to indicate the final distance.
Claim 3
Dependent Claim
14 words
A device as claimed in claim 1 in which the predetermined quantity is four.
Claim 4
Dependent Claim
14 words
A device as claimed in claim 1 in which the predetermined quantity is five.
Claim 5
Dependent Claim
26 words
A device as claimed in claim 1 in which the accumulating means is a counter to count a serial train of pulses representing a phase difference.
Claim 6
Dependent Claim
17 words
A device as claimed in claim 4 in which the counter is a two digit decimal counter.
Claim 7
Dependent Claim
44 words
A device as claimed in claim 4 in which the controlling means is digital logic which presets the accumulating means to a value corresponding to the correcting quantity before a phase measurement is accumulated so that the correcting quantity is added to the measurement.
Claim 8
Dependent Claim
16 words
A device as claimed in claim 1 in which the indicating means is a visual display.
Claim 9
Dependent Claim
14 words
A device as claimed in claim 1 in combination with electro-magnetic distance measuring apparatus.
Claim 10
Dependent Claim
14 words
A device as claimed in claim 6 in combination with electro-magnetic distance measuring apparatus.
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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |