US3990069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for monitoring changes in the fluidic impedance or volume of an enclosure
Assignee: Individual
•
Filing: 1974-12-10
•
Granted: 1976-11-02
•
Expires: 1994-12-10
Abstract
Abstract A monitoring system for detecting changes in the fluidic impedance of the boundary regions or volume of an enclosure, including detecting entry into, as well as certain movements within, a substantially sealed enclosure by means of synchronous detection of a modulated pressure signal within the enclosure. The air pressure within the enclosure is modulated at a predetermined amplitude and at a frequency which is sufficiently low to substantially avoid reverberation and wave interference effects, and means tuned to that frequency produce electrical signals indicative of the amplitude and phase, whereby entry into or exit from the enclosure, opening of a chamber within the enclosure, or blockage or unblockage of passageways within the enclosure vary the amplitude and/or phase of the modulated pressure, thereby causing an electrical signal to vary sufficiently to actuate an alarm.
Inventors
- 👤 Mark Schuman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:25
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/20
Claims Analysis
Total Claims: 70
Claim 1
Independent Claim
125 words
In an enclosure having at least one boundary region defining at least one bounded region wherein any bounded region has a lower fluidic impedance than any of its boundary regions, a monitoring system for detecting a change in the fluidic impedance of at least one of said boundary regions or for detecting the movement of a portion of at least one of said boundary regions of said enclosure comprising means for inducing a predetermined substantially uniform variation in pressure with respect to time within at least one bounded region of said enclosure, means for monitoring deviation from said predetermined variation, wherein the induced pressure variation is spatially substantially uniform within any said bounded region of said enclosure at most given instants in time during monitoring.
Claim 2
Dependent Claim
125 words
In an enclosure having at least one boundary region defining at least one bounded region wherein any bounded region has a lower fluidic impedance than any of its boundary regions, a monitoring system for detecting a change in the fluidic impedance of at least one of said boundary regions or for detecting the movement of a portion of at least one of said boundary regions of said enclosure comprising means for inducing a predetermined substantially uniform variation in pressure with respect to time within at least one bounded region of said enclosure, means for monitoring deviation from said predetermined variation, wherein the induced pressure variation is spatially substantially uniform within any said bounded region of said enclosure at most given instants in time during monitoring.
Claim 3
Dependent Claim
41 words
The monitoring system of claim 1 wherein said means for monitoring includes means for producing a signal corresponding to the induced variation in pressure within said at least one bounded region, and means for integrating said signal with respect to time.
Claim 4
Dependent Claim
25 words
The monitoring system of claim 1 wherein the means for inducing includes means for conducting fluid across a boundary region in a substantially oscillatory manner.
Claim 5
Dependent Claim
40 words
The monitoring system of claim 3 wherein the means for conducting includes a port and conduit means for conducting gas across a boundary region, and means adapted to repeatedly block the flow of fluid in said port and conduit means.
Claim 6
Dependent Claim
32 words
The monitoring system of claim 3 wherein said means for conducting fluid includes a motor-driven blade mounted for rotation and adapted to alternately block and unblock a port in said conducting means.
Claim 7
Dependent Claim
14 words
The monitoring system of claim 3 wherein said fluid conducting means includes a fan.
Claim 8
Dependent Claim
17 words
The monitoring system of claim 1 wherein said means for inducing includes means for repeatedly heating fluid.
Claim 9
Dependent Claim
21 words
The monitoring system of claim 1 wherein said inducing means includes means for varying pressure in at least two bounded regions.
Claim 10
Dependent Claim
28 words
The monitoring system of claim 8, wherein the means for monitoring includes means for monitoring the difference between the varying pressures in said at least two bounded regions.
Claim 11
Dependent Claim
29 words
The monitoring system of claim 8, wherein the means for monitoring includes a pressure sensor in at least two of said at least two bounded regions of the enclosure.
Claim 12
Dependent Claim
27 words
The monitoring system of claim 10 wherein the means for monitoring further includes means for comparing the pressure variations sensed by at least two of said sensors.
Claim 13
Dependent Claim
15 words
The monitoring system of claim 11 wherein the means for comparing includes synchronous detection means.
Claim 14
Dependent Claim
24 words
The monitoring system of claim 8 wherein the monitoring means includes means for comparing the induced variations in the at least two bounded regions.
Claim 15
Dependent Claim
69 words
The monitoring system of claim 1 wherein said inducing means includes means for varying pressure in at least two bounded regions of the enclosure such that the induced pressure variations in the at least two bounded regions have predetermined relative amplitudes and a common frequency, said means for monitoring including means responsive to a deviation in said relative amplitudes, and means for tuning said monitoring means to said frequency.
Claim 16
Dependent Claim
21 words
The monitoring system of claim 14 wherein said means for monitoring includes means for comparing the amplitudes at a predetermined phase.
Claim 17
Dependent Claim
40 words
The monitoring system of claim 1 wherein said means for inducing a variation in pressure includes means to modulate the pressure at a predetermined amplitude, said means for monitoring including indicator means responsive to a deviation in said predetermined amplitude.
Claim 18
Dependent Claim
48 words
The monitoring system of claim 1 wherein said means for inducing a variation in pressure includes means to modulate the pressure in at least one bounded region at a predetermined frequency and phase, said means for monitoring including indicator means responsive to a deviation in said predetermined phase.
Claim 19
Dependent Claim
32 words
The monitoring system of claim 1 wherein said means for inducing a variation in pressure includes means to modulate the pressure at a frequency between about 0.1 Hertz and about 10.0 Hertz.
Claim 20
Dependent Claim
25 words
The monitoring system of claim 1 wherein the means for monitoring includes means for tuning to the induced variation in pressure and attenuating spurious signals.
Claim 21
Dependent Claim
26 words
The monitoring system of claim 1 wherein said means for monitoring includes sensing means tuned to substantially the frequency and phase of said means for inducing.
Claim 22
Dependent Claim
22 words
The monitoring system of claim 1 wherein the means for monitoring includes synchronous detection means for improving operating characteristics of the system.
Claim 23
Dependent Claim
26 words
The monitoring system of claim 1 wherein the means for monitoring includes means for correcting the system output for the performance of the means for inducing.
Claim 24
Dependent Claim
76 words
The monitoring system of claim 1 wherein said means for monitoring includes means for producing an electrical signal substantially corresponding to the induced variation in the pressure within said at least one bounded region, and filtering and switching means for synchronously rectifying said signal at the frequency of the means for inducing and at a selected phase relative to the means for inducing, so as to attenuate spurious signals and noise at other frequencies and phases.
Claim 25
Dependent Claim
34 words
The monitoring system of claim 1 wherein said means for inducing a variation in pressure includes means to vary the pressure at a characteristic frequency which is less than or equal to 10 Hertz.
Claim 26
Dependent Claim
22 words
The monitoring system of claim 1 wherein the monitoring means includes means for monitoring the difference in pressure across a boundary region.
Claim 27
Dependent Claim
27 words
The monitoring system of claim 25 wherein the means for monitoring includes means for tuning to the variation in said pressure difference and discriminating against spurious signals.
Claim 28
Dependent Claim
14 words
The monitoring system of claim 26 wherein the tuning means includes synchronous detection means.
Claim 29
Dependent Claim
17 words
The monitoring system of claim 1 wherein the means for monitoring includes at least two pressure transducers.
Claim 30
Dependent Claim
32 words
The monitoring system of claim 1 wherein the means for monitoring includes at least two pressure sensors and means for comparing the pressure variations sensed by at least two of the sensors.
Claim 31
Dependent Claim
30 words
The monitoring system of claim 1 wherein the means for inducing includes means for inducing substantially inverse pressure variations in two bounded regions on opposite sides of a boundary region.
Claim 32
Dependent Claim
22 words
The monitoring system of claim 30 wherein the means for monitoring includes means for monitoring pressure variations in the two bounded regions.
Claim 33
Dependent Claim
23 words
The monitoring system of claim 30 wherein the means for monitoring includes means for comparing the induced variations in the two bounded regions.
Claim 34
Dependent Claim
25 words
The monitoring system of claim 32 wherein the induced variations have a characteristic frequency, and means for tuning the comparing means to the characteristic frequency.
Claim 35
Dependent Claim
19 words
The monitoring system of claim 33 wherein said means for tuning includes synchronous detection means for sharpening said tuning.
Claim 36
Dependent Claim
23 words
The monitoring system of claim 30 wherein said means for monitoring includes means for monitoring the difference in pressure across the boundary region.
Claim 37
Dependent Claim
26 words
The monitoring system of claim 35 wherein the induced variations have a characteristic frequency, and means for substantially tuning the monitoring means to the characteristic frequency.
Claim 38
Dependent Claim
18 words
The monitoring system of claim 36 wherein the means for tuning includes means for synchronous rectification and filtering.
Claim 39
Dependent Claim
23 words
The monitoring system of claim 36 wherein the means for monitoring further includes means for averaging the deviation over a number of cycles.
Claim 40
Dependent Claim
20 words
The monitoring system of claim 38 wherein the means for monitoring further includes alarm means responsive to the averaged deviation.
Claim 41
Dependent Claim
27 words
The monitoring system of claim 35 wherein the induced variations have a primary frequency component which is at least 0.1 Hertz and no greater than 10.0 Hertz.
Claim 42
Dependent Claim
15 words
The monitoring system of claim 30 wherein the means for inducing includes a fan means.
Claim 43
Dependent Claim
26 words
The monitoring system of claim 41 wherein the means for inducing includes means for conducting fluid between the two bounded regions in a substantially oscillatory manner.
Claim 44
Dependent Claim
33 words
The monitoring system of claim 1 wherein the induced variation is substantially periodic, the periodic variation having a given fundamental frequency, and wherein the means for monitoring is tuned to the fundamental frequency.
Claim 45
Dependent Claim
15 words
The monitoring system of claim 43 wherein the means for monitoring includes synchronous rectification means.
Claim 46
Dependent Claim
129 words
In an enclosure having at least one boundary region defining at least one bounded region wherein said boundary regions provide significant impedance to fluid flow and are capable of supporting a significant differential pressure thereacross, a monitoring system for detecting a change in the fluidic impedance of at least one of said boundary regions or for detecting the movement of at least a portion of a boundary region, comprising means for inducing, with respect to time, a predetermined substantially uniform variation in the differential pressure across at least one boundary region of said enclosure, means for monitoring deviation from said predetermined variation, wherein the instantaneous induced pressure variation is spatially substantially uniform within any said bounded region of said enclosure at substantially any given instant in time during monitoring.
Claim 47
Dependent Claim
129 words
In an enclosure having at least one boundary region defining at least one bounded region wherein said boundary regions provide significant impedance to fluid flow and are capable of supporting a significant differential pressure thereacross, a monitoring system for detecting a change in the fluidic impedance of at least one of said boundary regions or for detecting the movement of at least a portion of a boundary region, comprising means for inducing, with respect to time, a predetermined substantially uniform variation in the differential pressure across at least one boundary region of said enclosure, means for monitoring deviation from said predetermined variation, wherein the instantaneous induced pressure variation is spatially substantially uniform within any said bounded region of said enclosure at substantially any given instant in time during monitoring.
Claim 48
Dependent Claim
32 words
The monitoring system of claim 45 wherein the means for inducing includes fluid temperature modification means, and means for varying fluid flow in heat transfer relationship with said fluid temperature modification means.
Claim 49
Dependent Claim
22 words
The monitoring system of claim 45 wherein the means for monitoring includes alarm means responsive to said deviation from said predetermined variation.
Claim 50
Dependent Claim
16 words
The monitoring system of claim 45 wherein the means for inducing includes a thermally powered device.
Claim 51
Dependent Claim
47 words
The monitoring system of claim 45 wherein the induced variation has a characteristic frequency, and wherein the monitoring means includes means responsive to a change in the phase of the induced variation in pressure in a bounded region relative to the phase of the means for inducing.
Claim 52
Dependent Claim
36 words
The monitoring system of claim 45 wherein the induced variation has a characteristic frequency, and wherein the monitoring means includes means for monitoring the induced variation at a selected phase relative to the means for inducing.
Claim 53
Dependent Claim
28 words
The monitoring system of claim 45 wherein the monitoring means includes means for generating a signal indicative of the induced variation and means for synchronously rectifying the signal.
Claim 54
Dependent Claim
17 words
The monitoring system of claim 51 wherein the monitoring means further includes means for averaging the signal.
Claim 55
Dependent Claim
26 words
The monitoring system of claim 45 wherein the induced variation is substantially periodic, and means for tuning the monitoring means to the frequency of the variation.
Claim 56
Dependent Claim
17 words
The monitoring system of claim 53 wherein the tuning means includes means for synchronous rectification and filtering.
Claim 57
Dependent Claim
21 words
The monitoring system of claim 53 wherein the means for inducing includes fan means for producing a flow of the fluid.
Claim 58
Dependent Claim
25 words
The monitoring system of claim 53 wherein the characteristic frequency of the induced variation is at least 0.1 Hertz and no greater than 10.0 Hertz.
Claim 59
Dependent Claim
22 words
The monitoring system of claim 45 wherein the means for inducing includes a fan means for producing a flow of the fluid.
Claim 60
Dependent Claim
34 words
The monitoring system of claim 45 wherein said means for inducing a variation in the differential pressure includes means to vary the differential pressure at a characteristic frequency which is less than 10.0 Hertz.
Claim 61
Dependent Claim
20 words
The monitoring system of claim 45 wherein the induced variation has a fundamental frequency between 0.1 Hertz and 10.0 Hertz.
Claim 62
Dependent Claim
17 words
The monitoring system of claim 45 wherein the means for monitoring includes at least two pressure transducers.
Claim 63
Dependent Claim
25 words
The monitoring system of claim 60 wherein the means for monitoring includes means for comparing the output signals of at least two of the transducers.
Claim 64
Dependent Claim
30 words
The monitoring system of claim 54 wherein said means for inducing includes means for making said pressure variation substantially cyclical, and wherein the means for monitoring includes synchronous detection means.
Claim 65
Dependent Claim
17 words
The monitoring system of claim 45 including means for substantially tuning the monitoring means to the variation.
Claim 66
Dependent Claim
27 words
The monitoring system of claim 54 wherein the induced variation has a characteristic frequency, and further including means for tuning the monitoring means to the characteristic frequency.
Claim 67
Dependent Claim
35 words
The monitoring system of claim 45 wherein the induced variation has a predetermined amplitude and frequency, and wherein the monitoring means includes means tuned to said frequency and responsive to a deviation in said amplitude.
Claim 68
Dependent Claim
17 words
The monitoring system of claim 65 wherein the monitoring means includes means for synchronous rectification and filtering.
Claim 69
Dependent Claim
24 words
The monitoring system of claim 45 wherein the means for inducing includes means for producing a differential pressure of substantially constant amplitude and frequency.
Claim 70
Dependent Claim
25 words
The monitoring system of claim 45 wherein the inducing means includes means for inducing substantially inverse pressure variations on opposite sides of a boundary region.
References Cited (Backward Citations)
GB656399A
Cited
US3513463A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |