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US4070575A
Expired / Lapsed
US
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Measurement of flow of particulate material by sensing the shadow profile
Assignee: Coal Industry Patents Ltd
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Filing: 1976-01-27
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Granted: 1978-01-24
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Expires: 1996-01-27
Abstract
Abstract A portion of a beam of light directed towards a flow of particulate material is interrupted with an edge such that the edge casts a shadow across the material. The shadow profile is sensed and a signal indicative of the sensed shadow profile is derived and monitored as a function of flow velocity to determine the volume of flow.
Inventors
- 👤 Andrew Howard Donaldson Park
- 👤 Brian George Pidgeon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:49
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/66; G01F1/661; G01F17/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
A method of measuring flow of particulate material comprising directing a beam of light towards the flow of particulate material, interrupting a portion of the beam with an edge of a member such that the edge casts a shadow across the flow of particulate material, sensing the shadow profile, deriving a signal indicative of the shadow profile, and monitoring the derived signal as a function of flow velocity to determine the volume of flow.
Claim 2
Independent Claim
74 words
A method of measuring flow of particulate material comprising directing a beam of light towards the flow of particulate material, interrupting a portion of the beam with an edge of a member such that the edge casts a shadow across the flow of particulate material, sensing the shadow profile, deriving a signal indicative of the shadow profile, and monitoring the derived signal as a function of flow velocity to determine the volume of flow.
Claim 3
Dependent Claim
85 words
Apparatus for measuring flow of particulate material comprising a light beam emitter for directing a light beam towards the flow of particulate material, a member having an edge for interrupting the emitted light beam such that in operation the edge casts a shadow across the flow of particulate material, a sensor for sensing the shadow profile and deriving a signal indicative of the shadow profile, and a monitor for receiving the derived signal as a function of flow velocity to determine the volume of flow.
Claim 4
Dependent Claim
85 words
Apparatus for measuring flow of particulate material comprising a light beam emitter for directing a light beam towards the flow of particulate material, a member having an edge for interrupting the emitted light beam such that in operation the edge casts a shadow across the flow of particulate material, a sensor for sensing the shadow profile and deriving a signal indicative of the shadow profile, and a monitor for receiving the derived signal as a function of flow velocity to determine the volume of flow.
Claim 5
Dependent Claim
15 words
Apparatus as claimed in claim 2, in which the profile of the edge is straight.
Claim 6
Dependent Claim
19 words
Apparatus as claimed in claim 2, in which the sensor comprises a lens device and a photo-diode array instrument.
Claim 7
Dependent Claim
42 words
Apparatus as claimed in claim 2 in which the light beam emitter is mounted to emit light at an angle to the flow of particulate material, and in which the sensor is mounted at an angle to the flow of particulate material.
Claim 8
Dependent Claim
27 words
Apparatus as claimed in claim 5 in which the angle of mounting of the light beam emitter and the angle of mounting of the sensor are similar.
Claim 9
Dependent Claim
50 words
Apparatus as claimed in claim 5 in which the member having an edge for interrupting the emitted light beam extends upward from a direction of particulate material into the light beam, and wherein the edge which casts a shadow across the flow of particulate material is uppermost on the member.
Claim 10
Dependent Claim
77 words
Apparatus as claimed in claim 2 in which the light beam emitter is positioned above particulate material, and in which the sensor is positioned above particulate material spaced from the light beam emitter, and in which the member is positioned above the particulate material and below the light beam emitter in a direction toward the sensor and wherein the edge which casts a shadow across the flow of particulate material is an upper edge of the member.
Claim 11
Dependent Claim
30 words
The method of measuring flow of particulate material of claim 1 wherein the interrupting step comprises interrupting a lower portion of the beam with an upper edge of a member.
Claim 12
Dependent Claim
59 words
The method of measuring flow of particulate material as claimed in claim 1 wherein the directing step comprises directing a light beam downward at an angle toward flow of particulate material, wherein the interrupting step comprises interrupting a lower portion of the light beam with a member whose upper edge casts a shadow across the flow of particulate material.
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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |