US3720818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of measurement and apparatus therefor
Assignee: Rank Organization Ltd
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Filing: 1971-01-29
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Granted: 1973-03-13
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Expires: 1991-01-29
Abstract
Abstract Apparatus and method for determining a parameter which will effectively characterize the fluctuations of a dependent variable with respect to an independent variable, such as the height of a surface profile with respect to position along the surface. The apparatus includes means for detecting the variations of the independent variable such as a transducer for detecting the variations of the height of the surface profile along a line in the surface to obtain a signal representing the said variations, and means for differentiating the signal representing the said variations to provide a rate signal depending on the rate of change of the profile height, and means for combining the two signals, such as by integrating each and then dividing one by the other, to provide the said parameter which characterizes the fluctuations.
Inventors
- 👤 R Spragg
- 👤 D Whitehouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:23
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/34; G06; G06G; G06G7/00; G06G7/12; G06G7/20; G07; G07C; G07C3/00; G07C3/14
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
114 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the mean modulus of said dependent variable over said range, means providing a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 2
Dependent Claim
114 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the mean modulus of said dependent variable over said range, means providing a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 3
Dependent Claim
114 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the mean modulus of said dependent variable over said range, means providing a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 4
Dependent Claim
114 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the mean modulus of said dependent variable over said range, means providing a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 5
Dependent Claim
57 words
The apparatus of claim 1, wherein said means providing said second signal representing the mean modulus of said rate of change of said dependent variable with respect to said independent variable comprises a rectifier feeding an integrator and fed with a signal representing the rate of change of said dependent variable with respect to said independent variable.
Claim 6
Dependent Claim
29 words
The apparatus of claim 2 wherein said second signal is obtained at the output of a differentiation circuit fed with said signal representing said value of said dependent variable.
Claim 7
Dependent Claim
54 words
The apparatus of claim 1, wherein said parameter to be determined characterizes the profile of a surface of a body, said apparatus further comprising means for determining the distance of said surface from a reference line, thereby to provide a signal representing said dependent variable over a range of positions spaced over said surface.
Claim 8
Dependent Claim
55 words
The apparatus of claim 4 further comprising a probe movable with respect to said surface along a line in contact with said surface and responsive to changes in said profile of said surface to produce a signal in dependence thereon, said probe comprising said means determining said distance of said surface from said reference line.
Claim 9
Dependent Claim
55 words
The apparatus of claim 5 wherein said probe is a transducer operable at a modulation frequency, and further comprising: a carrier oscillator from which said transducer is fed, said carrier oscillator determining the modulation frequency, means for demodulating said signal from said transducer, and means for removing the low frequency component of said demodulated signal.
Claim 10
Dependent Claim
42 words
The apparatus Of claim 6, further comprising means for removing any components of said demodulated signal having a frequency greater than about 6 octaves above the lowest frequency passed by said means for removing said low frequency component of said demodulated signal.
Claim 11
Dependent Claim
76 words
The apparatus of claim 5 further comprising means for rectifying and integrating said demodulated signal, means for differentiating said demodulated signal, and means for rectifying and integrating said differentiated signal to provide respectively a first signal representing said mean modulus of the distance of said surface of said profile from said reference line and a second signal representing the mean modulus of the rate of change of said distance of said surface from said reference line.
Claim 12
Dependent Claim
59 words
The apparatus of claim 8 further comprising a divider circuit for producing an output signal representing the division of said first signal representing said mean modulus of the distance of said surface from said reference line by said second signal representing said mean modulus of the rate of change of the distance of said surface from said reference line.
Claim 13
Dependent Claim
17 words
The apparatus of claim 8 wherein said means for rectifying said demodulated signal are full wave rectifiers.
Claim 14
Dependent Claim
85 words
The apparatus of claim 5 further comprising means for rectifying and integrating said demodulated signal, means for generating a plurality of reference signals representing a series of attainable values of said demodulated signal, means for detecting the crossing by said demodulated signal of said reference value to produce an output pulse in dependence thereon, and means for counting said pulses produced by said detector, thereby to produce a numerical representation of the rate of change of said distance of said surface from said reference line.
Claim 15
Dependent Claim
84 words
The apparatus of claim 5 further comprising: means for rectifying and integrating said demodulated signal, means for generating a plurality of reference signals representing a series of attainable values of said demodulated signal, means for detecting the crossing by said demodulated signal of said reference value to produce an output pulse in dependence thereon, and means for counting said pulses produced by said detector to produce a numerical representation of the rate of change of said distance of said surface from said surface line.
Claim 16
Dependent Claim
61 words
The apparatus of claim 4 comprising means for displaying said first and second signals respectively representing said mean modulus of said distance of said surface from said reference line, said mean modulus of said rate of change of said distance of said surface from said reference line, and said signal representing said parameter determined by said combination of said two signals.
Claim 17
Dependent Claim
36 words
Apparatus according to claim 1 wherein said modifying means comprises means for modifying the first signal by means of the second signal to provide the third signal, said third signal directly representing said average wavelength parameter.
Claim 18
Dependent Claim
34 words
The apparatus of claim 14 wherein said modifying means modifying said first signal by means of said second signal is a divider circuit in which said first signal is divisible by said second signal.
Claim 19
Dependent Claim
38 words
Apparatus according to claim 1 wherein said modifying means comprises means for modifying the second signal by means of the first signal to provide the third signal, the third signal representing the reciprocal of said average wavelength parameter.
Claim 20
Dependent Claim
34 words
The apparatus of claim 16 wherein said modifying means modifying said second signal by means of said first signal is a divider circuit in which said second signal is divisible by said first signal.
Claim 21
Dependent Claim
118 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the root mean squarE of said dependent variable over said range, means providing a second signal representing the root mean square of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing a roof mean square wavelength parameter characterizing said spectrum.
Claim 22
Dependent Claim
118 words
Apparatus for characterizing the spectrum of a dependent variable with respect to an independent variable, said apparatus comprising: means determining the value of said dependent variable over a range of values of said independent variable, means providing a first signal representing the root mean squarE of said dependent variable over said range, means providing a second signal representing the root mean square of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying means for modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing a roof mean square wavelength parameter characterizing said spectrum.
Claim 23
Dependent Claim
38 words
Apparatus according to claim 18 wherein said modifying means comprises means for modifying the first signal by means of the second signal to provide the third signal, said third signal directly representing said root mean square wavelength parameter.
Claim 24
Dependent Claim
34 words
The apparatus of claim 19 wherein said modifying means modifying said first signal by means of said second signal is a divider circuit in which said first signal is divisible by said second signal.
Claim 25
Dependent Claim
40 words
Apparatus according to claim 18 wherein said modifying means comprises means for modifying the second signal by means of the first signal to provide the third signal, the third signal representing the reciprocal of said root mean square wavelength parameter.
Claim 26
Dependent Claim
34 words
The apparatus of claim 11 wherein said modifying means modifying said second signal by means of said first signal is a divider circuit in which said second signal is divisible by said first signal.
Claim 27
Dependent Claim
62 words
The apparatus of claim 18 wherein said means providing said second signal representing the root mean square of said rate of change of said dependent variable with respect to said independent variable comprises a rectifier feeding an integrator and fed from a differentiation circuit with a signal representing the rate of change of said dependent variable with respect to said independent variable.
Claim 28
Dependent Claim
43 words
The apparatus of claim 23 wherein said signal representing said rate of change of said dependent variable with respect to said independent variable is obtained at the output of the differentiation circuit fed with said signal representing said value of said dependent variable.
Claim 29
Dependent Claim
53 words
The apparatus of claim 18 wherein said parameter to be determined characterizes the profile of a surface of a body said apparatus including means for determining the distance of said surface from a reference line, thereby to provide a signal representing said dependent variable over a range of positions spaced over said surface.
Claim 30
Dependent Claim
55 words
The apparatus of claim 25 further comprising: a probe movable with respect to said surface along a line in contact with said surface and responsive to changes in said profile of said surface to produce a signal in dependence thereon, said probe comprising said means determining said distance of said surface from said reference line.
Claim 31
Dependent Claim
55 words
The apparatus of claim 26 wherein said probe is a transducer operable at a modulation frequency, and further comprising: a carrier oscillator from which said transducer is fed, said carrier oscillator determining said modulation frequency, means for demodulating said signal from said transducer, and means for removing any low frequency component of said demodulated signal.
Claim 32
Dependent Claim
42 words
The apparatus of claim 27, further comprising means for removing the components of said demodulated signal having a frequency greater than about 6 octaves above the lowest frequency passed by said means for removing said low frequency component of said demodulated signal.
Claim 33
Dependent Claim
78 words
The apparatus of claim 26 further comprising: means for rectifying and integrating said demodulated signal, means for differentiating said demodulated signal, and means for rectifying and integrating said differentiated signal to provide respectively a first signal representing said root mean square of the distance of said surface of said profile from said reference line and a second signal representing the root mean square of the rate of change of said distance of said surface from said reference line.
Claim 34
Dependent Claim
61 words
The apparatus of claim 29 further cOmprising a divider circuit for producing an output signal representing the division of said first signal representing said root mean square of the distance of said surface from said reference line by said second signal representing said root mean square of the rate of change of the distance of said surface from said reference line.
Claim 35
Dependent Claim
17 words
The apparatus of claim 29 wherein said means for rectifying said demodulated signal are square law rectifiers.
Claim 36
Dependent Claim
64 words
The apparatus of claim 25 further comprising means for displaying said first and second signals respectively representing said root mean square of said distance of said surface from said reference line, said root mean square of said rate of change of said distance of said surface from said reference line, and said signal representing said parameter determined by said combination of said two signals.
Claim 37
Independent Claim
110 words
A method of characterizing the spectrum of a dependent variable with respect to an independent variable comprising the steps of: determining the value of said dependent variable over a range of values of said independent variable, deriving a first signal representing the mean modulus of said dependent variable over said range, deriving a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 38
Independent Claim
110 words
A method of characterizing the spectrum of a dependent variable with respect to an independent variable comprising the steps of: determining the value of said dependent variable over a range of values of said independent variable, deriving a first signal representing the mean modulus of said dependent variable over said range, deriving a second signal representing the mean modulus of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing an average wavelength parameter characterizing said spectrum.
Claim 39
Dependent Claim
62 words
The method of claim 33 wherein said first signal representing said mean modulus of the rate of change of said dependent variable over said range is derived from a signal representing the value of said rate of change of said dependent variable which in turn is derived by differentiation of a signal representing the value of said dependent variable over said range.
Claim 40
Dependent Claim
49 words
The method of claim 33 wherein said parameter to be determined characterizes the profile of a surface of a body, said dependent variable being the distance of said surface of said body from a reference line and said independent variable being distance along said surface from a predetermined point.
Claim 41
Dependent Claim
44 words
The method of claim 35 wherein said signal representing the value of said dependent variable is obtained by passing a probe in contact with said surface along a predetermined line to obtain a signal representing the distance of said surface from a reference line.
Claim 42
Dependent Claim
61 words
The method of claim 36 wherein a signal representing said rate of change of said dependent variable is obtained by differentiation of said signal representing the distance of said surface from said reference line and is used to provide said first signal representing said mean modulus of said rate of change of said distance of said surface from said reference line.
Claim 43
Dependent Claim
44 words
The method of claim 35, wherein said parameter determined is the rate of said mean modulus of distance of said surface from said reference line to said mean modulus of said rate of change of said distance of said surface from said reference line.
Claim 44
Dependent Claim
36 words
A method according to claim 33 wherein the step of modifying comprises modifying the first signal by means of the second signal to provide the third signal, said third signal directly representing said average wavelength parameter.
Claim 45
Dependent Claim
28 words
The method of claim 39 wherein said first signal is divided by said second signal to provide said third signal representing the average wavelength parameter characterizing said spectrum.
Claim 46
Dependent Claim
38 words
A method according to claim 33 wherein the step of modifying comprises modifying the second signal by means of the first signal to provide the third signal, the third signal representing the reciprocal of said average wavelength parameter.
Claim 47
Dependent Claim
30 words
The method of claim 41 wherein said second signal is divided by said first signal to provide said signal representing the reciprocal of the average wavelength parameter characterizing said spectrum.
Claim 48
Independent Claim
114 words
A method of characterizing the spectrum of a dependent variable with respect to an independent variable comprising the steps of: determining the value of said dependent variable over a range of values of said independent variable, deriving a first signal representing the root mean square of said dependent variable over said range, deriving a second signal representing the root mean square of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing a root mean square wavelength parameter characterizing said spectrum.
Claim 49
Independent Claim
114 words
A method of characterizing the spectrum of a dependent variable with respect to an independent variable comprising the steps of: determining the value of said dependent variable over a range of values of said independent variable, deriving a first signal representing the root mean square of said dependent variable over said range, deriving a second signal representing the root mean square of the rate of change of said dependent variable with respect to said independent variable over said range, and modifying one of said first and second signals by means of the other of said first and second signals to provide a third signal representing a root mean square wavelength parameter characterizing said spectrum.
Claim 50
Dependent Claim
38 words
A method according to claim 43 wherein the step of modifying comprises modifying the first signal by means of the second signal to provide the third signal, said third signal directly representing said root mean square wavelength parameter.
Claim 51
Dependent Claim
30 words
The method of claim 44 wherein said first signal is divided by said second signal to provide said third signal representing the root mean square wavelength parameter characterizing said spectrum.
Claim 52
Dependent Claim
40 words
A method according to claim 43 wherein the step of modifying comprises modifying the second signal by means of the first signal to provide the third signal, the third signal representing the reciprocal of said root mean square parameter wavelength.
Claim 53
Dependent Claim
33 words
The method of claim 46 wherein said second signal is divided by said first signal to provide said third signal representing the reciprocal of the root mean square wavelength parameter characterizing said spectrum.
Claim 54
Dependent Claim
61 words
The method of claim 43 wherein said first signal representing said root mean square of the rate of change of said dependent variable over said range is derived from a signal representing the value of said rate of change of said dependent variable which is derived by differentiation of a signal representing the value of said dependent variable over said range.
Claim 55
Dependent Claim
49 words
The method of claim 43 wherein said parameter to be determined characterizes the profile of a surface of a body, said dependent variable being the distance of said surface of said body from a reference line and said independent variable being distance along said surface from a predetermined point.
Claim 56
Dependent Claim
44 words
The method of claim 49 wherein said signal representing the value of said dependent variable is obtained by passing a probe in contact with said surface along a predetermined line to obtain a signal representing the difference of said surface from a reference line.
Claim 57
Dependent Claim
61 words
The method of claim 50 wherein a signal representing said rate of change of said dependent variable is obtained by differentiation of said signal representing the distance of said surface from said reference line and used to provide said first signal representing said root mean square of said rate of change of said distance of said surface from said reference line.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |