US3795906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic system distinguishing between good knots and defects in a moving strand
Assignee: Leesona Corp
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Filing: 1972-05-19
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Granted: 1974-03-05
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Expires: 1992-05-19
Abstract
Abstract Two photocell detectors are spaced along a path of a moving strand with a gap of known fixed distance therebetween. The photocells view a length of the strand on each side of a knot or defect in the strand when the knot is presented in the gap. An inspection cycle is started by entry into the detectors of a knot or defect and a defective knot or defect is determined by comparing the dynamic signal status of a photocell spaced some distance behind the knot with the signal taken from a photocell ahead of the defect and stored. The existence of a signal at this position or of an exceptionally large signal indicated by comparison at the time of initiation of the cycle indicates the presence of a defective knot.
Inventors
- 👤 R Erbstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:48
CPC Classifications
B; B65; B65H; B65H63/00; B65H63/06; B65H63/062; B65H63/065; B65H2701/00; B65H2701/30; B65H2701/31
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
128 words
Electronic apparatus processing a moving knotted strand such as yarn to detect defects therein and pass good knots comprising in combination, a pair of detection means sampling the strand at two positions successively along its path of movement with a gap therebetween, means responsive to the entry of a knot or defect when it enters a first of said positions to initiate an inspection cycle, means storing a signal derived from the entry of a knot by one of said detection means, and means comparing during said inspection cycle the stored signal with the current signal being received from said strand by the other of said detection means to derive a defect signal upon a signal imbalance when one of said signals is significantly greater than the other.
Claim 2
Dependent Claim
128 words
Electronic apparatus processing a moving knotted strand such as yarn to detect defects therein and pass good knots comprising in combination, a pair of detection means sampling the strand at two positions successively along its path of movement with a gap therebetween, means responsive to the entry of a knot or defect when it enters a first of said positions to initiate an inspection cycle, means storing a signal derived from the entry of a knot by one of said detection means, and means comparing during said inspection cycle the stored signal with the current signal being received from said strand by the other of said detection means to derive a defect signal upon a signal imbalance when one of said signals is significantly greater than the other.
Claim 3
Dependent Claim
58 words
Apparatus as defined in claim 1 wherein the pair of detection means comprises a pair of photoelectric cells and including means detecting entry of the knot or defect at each of the cells and producing therefrom a defect signal, and means eliminating the defect signal during the time the defect is viewed only by the first detection means.
Claim 4
Dependent Claim
46 words
Apparatus as defined in claim 2 including a timing circuit generating a signal used to control said means eliminating the defect signal, said timing circuit producing said signal a predetermined time after said defect is first viewed by the second successive one of said detection means.
Claim 5
Dependent Claim
24 words
Apparatus as defined in claim 3 including further timing means for processing said defect signal when said signal imbalance persists beyond a predetermined time.
Claim 6
Dependent Claim
37 words
Apparatus as defined in claim 1 wherein the comparing means include timing means for producing the imbalance signal only when the defect persists beyond a predetermined time span during which a good knot is expected to pass.
Claim 7
Dependent Claim
24 words
Apparatus as defined in claim 5 including separate amplifying channels processing the signals from each detection means to provide signals to said comparison means.
Claim 8
Dependent Claim
35 words
Apparatus as defined in claim 1 wherein said stored signal is derived from one of said detection means and the comparing means compares the stored signal with the current signal on the other detection means.
Claim 9
Independent Claim
77 words
The method of distinguishing between a good knot and an unacceptable defect in a moving strand such as yarn, comprising the steps of, detecting in a moving strand enlarged portions presented at a detection station, timing the duration of the presence of the enlarged portions detected, and producing an alarm only when the enlarged portions are present for a period beyond a predetermined time span approximating the time span during which good knots pAss said detection station.
Claim 10
Independent Claim
77 words
The method of distinguishing between a good knot and an unacceptable defect in a moving strand such as yarn, comprising the steps of, detecting in a moving strand enlarged portions presented at a detection station, timing the duration of the presence of the enlarged portions detected, and producing an alarm only when the enlarged portions are present for a period beyond a predetermined time span approximating the time span during which good knots pAss said detection station.
Claim 11
Dependent Claim
35 words
The method defined in claim 8 wherein the step of detecting the enlarged portions of the strand includes sensing the strand at two successive detection station positions along the path of movement of the strand.
Claim 12
Dependent Claim
38 words
The method defined in claim 9 including the step of piecing up two broken ends in a knotter away from said two successive positions and thereafter moving the pieced up strand into both said detection station positions simultaneously.
Claim 13
Dependent Claim
30 words
The method defined in claim 8, wherein the detecting step includes impinging diffused light on the moving strand and processing collimated diffused light leaving the strand at said detection station.
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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |