Patent US3751894A successfully refreshed from Google Patents.
US3751894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
False twisting of yarns
Assignee: LAMBEG IND RES ASS
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Filing: 1970-03-05
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Granted: 1973-08-14
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Expires: 1990-03-05
Abstract
Abstract This invention concerns the false twisting of strands as for example, yarns, tapes and films. The false twisting is effected as the strand is continuously travelled around a freely rotatable roller in the form of a loop, the beginning and end of which constitutes a close simple knot in contact with the roller periphery. The frictional contact of the strand with itself at the knot causes false twist to run back in the strand. The stand leaves the roller in a non-tangential direction. This method of false twisting may be used as a substitute for known methods in the production of modified continuous filament yarns, or to produce preliminary or additive false twist in such cases; in the treatment of wet-spun linen yarns to improve their characteristics; and in the treatment of film either to separate pre-formed filaments therein or to fibrillate it.
Inventors
- 👤 J Ruddell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:38
CPC Classifications
D; D01; D01H; D01H1/00; D01H1/11; D02; D02G; D02G1/00; D02G1/02; D02G1/0206; D02G1/0226; G; G01; G01G; G01G17/00; G01G17/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
85 words
A method of false twisting a strand comprising the steps of travelling the strand continuously onto and around a cylindrical surface, which surface is freely mounted for rotation about its cylindrical axis, passing the strand just prior to leaving said surface over and then under that part of itself which is then just arriving on the surface to form a close simple knot in contact with the surface, and conveying the strand leaving the surface away in a non-tangential direction with respect to the surface.
Claim 2
Independent Claim
85 words
A method of false twisting a strand comprising the steps of travelling the strand continuously onto and around a cylindrical surface, which surface is freely mounted for rotation about its cylindrical axis, passing the strand just prior to leaving said surface over and then under that part of itself which is then just arriving on the surface to form a close simple knot in contact with the surface, and conveying the strand leaving the surface away in a non-tangential direction with respect to the surface.
Claim 3
Dependent Claim
39 words
A method of processing a strand continuously which includes subjecting the yarn sequentially to two false-twisting operations, at least one of which is carried out wholly or partly by the method of false twisting as claimed in claim 1.
Claim 4
Dependent Claim
55 words
A method as claimed in claim 2 in which the yarn is passed through a rotating false-twist tube having a transverse pin which acts as a twist-trapping device, the false-twist thus generated being set upstream of the tube, and in which the yarn is first subjected to an earlier false-twisting operation in the same sense.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 2 in which the level of the earlier false-twist is less than the level of the later false-twist.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 4 in which the earlier false-twist is set, but to a lesser degree than that of the later false-twist.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1 in which the surface is that of the roller which is the twist-trapper of a rotating false-twisting device.
Claim 8
Dependent Claim
38 words
A method as claimed in claim 6 in which the sense of the false-twist generated by virtue of the knot is the same as that of the false-twist which arises by virtue of the rotation of the device.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 6 in which the roller is mounted transversely of the device at right-angles to the axis of rotation of the latter.
Claim 10
Dependent Claim
29 words
A method as claimed in claim 6 in which the roller is mounted transversely of the device, but at an angle to the axis of rotation of the device.
Claim 11
Dependent Claim
22 words
A method as claimed in claim 1 in which the surface is that of the roller which is mounted on air bearings.
Claim 12
Dependent Claim
31 words
A continuous method of processing a strand in the form of wet-spun flax yarn which includes the step of false-twisting the yarn, according to the method as claimed in claim 1.
Claim 13
Dependent Claim
33 words
A continuous method of processing a strand in the form of a film of interconnected filaments which includes the step of false-twisting the film, according to the method as claimed in claim 1.
Claim 14
Dependent Claim
32 words
A method of fibrillating a strand in the form of a longitudinally oriented polymeric film which includes the step of false-twisting the film according to the method as claimed in claim 1.
Claim 15
Independent Claim
24 words
A method of making yarn by break-spinning in which the yarn as it is made is false-twisting by the method as claimed in claim
Claim 16
Dependent Claim
136 words
Apparatus for false twisting strand material including: means for causing said strand continuously to travel from a supply package to a wind up means; and disposed therebetween, in sequence, a freely rotatable roller having a concave periphery around which the yarn may loop and at the same time form a simple knot; a guide over which the yarn may then pass, said guide being capable of adjustment for the purpose of varying the angle between the strand approaching and leaving the roller; a heater disposed after said guide; and a false twisting device disposed after said heater, said false twisting device comprising a rotatable false twisting tube including a twist-trapper in the form of a freely rotatable roller mounted transversely thereof about which the yarn may loop and at the same time form a simple knot.
Claim 17
Dependent Claim
136 words
Apparatus for false twisting strand material including: means for causing said strand continuously to travel from a supply package to a wind up means; and disposed therebetween, in sequence, a freely rotatable roller having a concave periphery around which the yarn may loop and at the same time form a simple knot; a guide over which the yarn may then pass, said guide being capable of adjustment for the purpose of varying the angle between the strand approaching and leaving the roller; a heater disposed after said guide; and a false twisting device disposed after said heater, said false twisting device comprising a rotatable false twisting tube including a twist-trapper in the form of a freely rotatable roller mounted transversely thereof about which the yarn may loop and at the same time form a simple knot.
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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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |