US3818236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting broken threads or other disturbances in a fibre web
Assignee: Nordiska Maskinfilt AB
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Filing: 1972-08-17
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Granted: 1974-06-18
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Expires: 1992-08-17
Abstract
Abstract An apparatus for the supervision of fibrous webs, or other sheet-like material, particularly within the textile and paper industries, with the purpose of detecting faults in webs. An emitter is positioned at one side of the web and arranged to give off a beam of light essentially at right angles to the web extension. A receiver, positioned at the opposite side of the web, receives the beam of light. In accordance with the invention, the beam is imparted a particular movement covering an area of the web where faults are likely to arise and the immediate vicinity of said area. Evaluation means register any disturbances and compare them with a predetermined value, and upon excess of said predetermined value an impulse is emitted to a warning and/or stopping mechanism.
Inventors
- 👤 B Lind
- 👤 M Mansson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:04
CPC Classifications
D; D03; D03D; D03D51/00; D03D51/18; D03D51/20; D03D51/28
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
183 words
An improved apparatus for detecting disturbances of a fibrous web, such as broken threads, comprising an emitter giving off a beam of light directed essentially at right angles to the threads, a receiver positioned at thE opposite side of the threads and arranged to measure a change of intensity to which said beam of light is subjected when the path of said beam of light is interrupted, e.g., by a thread, means connected to said receiver for emitting, in response to a predetermined disturbance, an impulse capable of providing circuit response, the improvement comprising the emitter giving off an essentially coherent beam of light, a device provided to impart to said beam of light a movement of travel within an area where disturbances are expected to occur, said means connected to said receiver including counting means to count the number of disturbances per time unit and comparatory means to compare said number of disturbances per time unit with a predetermined number, and to emit said impulse in case of any discrepancy between said number of disturbances per time unit and said predetermined number.
Claim 2
Dependent Claim
183 words
An improved apparatus for detecting disturbances of a fibrous web, such as broken threads, comprising an emitter giving off a beam of light directed essentially at right angles to the threads, a receiver positioned at thE opposite side of the threads and arranged to measure a change of intensity to which said beam of light is subjected when the path of said beam of light is interrupted, e.g., by a thread, means connected to said receiver for emitting, in response to a predetermined disturbance, an impulse capable of providing circuit response, the improvement comprising the emitter giving off an essentially coherent beam of light, a device provided to impart to said beam of light a movement of travel within an area where disturbances are expected to occur, said means connected to said receiver including counting means to count the number of disturbances per time unit and comparatory means to compare said number of disturbances per time unit with a predetermined number, and to emit said impulse in case of any discrepancy between said number of disturbances per time unit and said predetermined number.
Claim 3
Dependent Claim
52 words
The improved apparatus as claimed in claim 1 utilized for detection of broken upper and lower warp threads in weaving, wherein said movement imparted to said beam of light by said device is effected within an area lying between the upper and the lower warp threads and above and beneath these threads.
Claim 4
Dependent Claim
22 words
The improved apparatus as claimed in claim 1, wherein a predetermined number of scanning operations of said area defines a measuring sequence.
Claim 5
Dependent Claim
33 words
The improved apparatus as claimed in claim 3, wherein said beam movement imparting device is arranged to give to said beam of light a particular movement a plurality of times per measuring sequence.
Claim 6
Dependent Claim
55 words
The improved apparatus as claimed in claim 1, wherein said beam movement imparting device consists of a hollow shaft, being rotated, through which hollow shaft passes said beam of light from the emitter, an optical element being provided on said shaft to give said beam of light a back and forth movement of adjustable width.
Claim 7
Dependent Claim
21 words
The improved apparatus as claimed in claim 1, wherein said beam of light emitted by said emitter is a laser beam.
Claim 8
Dependent Claim
22 words
The improved apparatus as claimed in claim 1, wherein both said emitter and said receiver are mounted rigidly relative to each other.
Claim 9
Dependent Claim
51 words
The improved apparatus as claimed in claim 1, comprising catcher means positioned beneath the threads to prevent broken threads from hanging down, this arrangement retaining said threads within said area being scanned by said beam of light without causing any disturbance to said beam of light by said catcher means themselves.
Claim 10
Dependent Claim
28 words
The improved apparatus as claimed in claim 1, comprising clock means connected between said receiver and said counting means and programmed to connect and disconnect said counting means.
Claim 11
Dependent Claim
30 words
The improved apparatus as claimed in claim 1, comprising breaking means, switch means connected between said receiver and said breaking means and programmed to carry out measurings at predetermined occasions.
Claim 12
Dependent Claim
18 words
The improved apparatus as claimed in claim 10, comprising means to interrupt measurings upon shift of weaving harness.
Claim 13
Dependent Claim
36 words
The improved apparatus as claimed in claim 1, comprising a unit coupled between the receiver and said counting means to emit an impulse to said counting means only upon change of intensity exceeding a predetermined value.
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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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |