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US3911698A Expired / Lapsed US ⏱️ 0.0 years remaining

Thread feeding device for inserted weft knitting machines

Assignee: JP Stevens and Co Inc
•
Filing: 1974-07-01
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Granted: 1975-10-14
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Expires: 1994-07-01
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Abstract

Abstract Elastic yarns are fed to knitting machines by measuring predetermined amounts of the elastic thread or yarn, which otherwise would be non-uniform in length or degree of stretch because of the high and not always uniform elasticity of the yarn. There are two distinct variants. Both variants include feeding out from yarn packages by driving the yarn package by friction on its surface. The first variant is for a weft knitting machine, such as a circular knitting machine, and in it a package of elastic yarn is moved along the needle line with a drive roller in contact with its surface, which roller turns as the package moves. The speed of the roller determines length of the elastic yarn paid out. Knitting is either by a non-elastic yarn which knits around the paid-out elastic yarn in the case of single knit machines, or in the case of double knit machines the paid-out elastic yarn may be sandwiched between the two layers of the double knit. The second variant deals with a multiple-package filling-thread-feeding device for warp knitting machines of the so-called ''''carousel'''' type in which thread from a plurality of packages, which are moved around by an endless chain, is fed to transfer chains provided with pins which carry the filling or weft threads to the knitting line, the motion of the packages stringing successive filling thread lengths from the pins on one chain to the pins on the other, and which provides for intermittent tensioning devices for the thread, for example spring-pressed discs, the tension being applied to the thread as it is clamped by the pin on one chain, then the tension releases, for example by a cam, until just before reaching the corresponding pin on the second chain and the tension is reapplied. The threading device is modified for feeding elastic yarn preferably by providing the yarn package, having a hollow core, with means for preventing rotation of the core for a portion of the travel of each package from carrier chain to carrier chain, the means preferably which apply a brake to the inside of the hollow core and cam which raises each package during a portion of the stringing from chain to chain which releases the braking means and permits rotation of the cores. The cams are of suitable length so that the elastic yarn is paid out a desired amount. The packages are moved along the cam and are turned thereby. In the unbraked portion of the travel a predetermined length of elastic yarn is paid out. Braking permits a predetermined stretch of the yarn. Instead of a large hollow core, packages may be on spindles to which intermittently brakes may be applied by any suitable means.

Inventors

  • 👤 Richard L Walford

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 14:25
CPC Classifications
D; D04; D04B; D04B23/00; D04B23/12

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 338 words
In an elastic weft thread feeding device for warp knitting machines comprising a first and second endless carrier with yarn clamping means thereon for opening and closing to clamp on weft thread, a third endless carrier provided with a plurality of yarn packages, each package having associated with it and moving therewith a tensioning means which, with elastic yarn, act as gripping means for the yarn, the endless carriers being synchronously driven and positioned so that as a package comes adjacent to the clamping means on the first carrier the means opens, clamps the yarn from the package, and then strings out the yarn as the package continues to move, the tensioning or gripping means being provided with means for applying pressure to the yarn intermittently to hold the yarn as it is grasped by the clamping means on the first carrier, maintaining gripping for a short distance beyond, the pressure then being released until the package approaches the clamping means on the second carrier and reactuated for a short distance as the package transfers its yarn to said clamping means on the second carrier, the yarn being tension free during the major portion of the travel of each packaGe between carriers, the impovement which comprises means for producing relative motion between packages having yarns that are elastic and a surface whereby the packages are rotated and yarn is unwound therefrom under substantially no tension, and means for intermittently braking the rotation of the yarn packages for sufficient periods to string the yarn from carrier to carrier in predetermined length when relaxed and at a predetermined tension, cutting means for cutting the elastic yarn after the package has passed the second carrier chain, and means for producing relative motion between the package and the surface, the package being free to turn, whereby a predetermined amount of yarn is wound off under substantially no tension and a tail is formed from the package of suitable length for clamping to the first carrier chain when the package passes across it.
Claim 2
Dependent Claim 338 words
In an elastic weft thread feeding device for warp knitting machines comprising a first and second endless carrier with yarn clamping means thereon for opening and closing to clamp on weft thread, a third endless carrier provided with a plurality of yarn packages, each package having associated with it and moving therewith a tensioning means which, with elastic yarn, act as gripping means for the yarn, the endless carriers being synchronously driven and positioned so that as a package comes adjacent to the clamping means on the first carrier the means opens, clamps the yarn from the package, and then strings out the yarn as the package continues to move, the tensioning or gripping means being provided with means for applying pressure to the yarn intermittently to hold the yarn as it is grasped by the clamping means on the first carrier, maintaining gripping for a short distance beyond, the pressure then being released until the package approaches the clamping means on the second carrier and reactuated for a short distance as the package transfers its yarn to said clamping means on the second carrier, the yarn being tension free during the major portion of the travel of each packaGe between carriers, the impovement which comprises means for producing relative motion between packages having yarns that are elastic and a surface whereby the packages are rotated and yarn is unwound therefrom under substantially no tension, and means for intermittently braking the rotation of the yarn packages for sufficient periods to string the yarn from carrier to carrier in predetermined length when relaxed and at a predetermined tension, cutting means for cutting the elastic yarn after the package has passed the second carrier chain, and means for producing relative motion between the package and the surface, the package being free to turn, whereby a predetermined amount of yarn is wound off under substantially no tension and a tail is formed from the package of suitable length for clamping to the first carrier chain when the package passes across it.
Claim 3
Dependent Claim 223 words
A weft thread feeding device according to claim 1 in which the yarn packages are carried on hollow cores of relatively large internal diameter, each package having within the hollow core a spindle attached to the third endless carrier and a second shaft connected to the spindle by spring means and carrying a brake show adapted, when the spindle is in its lowest position, to turn the shaft and apply the brake shoe to the inside of the hollow core, thereby locking the package against rotation, and means actuated by movement of the packages for raising the packages sufficiently to turn the shaft carrying the brake shoe to a point at which the brake shoe no longer contacts the core and hence the yarn is free to unwind, whereby when the packages carry elastic yarn it is first stretched by the locked packages as and after clamping to the first carrier, then raised to unlock the packge and permit yarn to unwind freely, whereby the yarn first unwinds to the point where it takes up the stretch and means adjacent the second endless carrier to again lock the package core from turning, the device being provided with a cutting means beyond the second endless carrier for sufficient distance to permit relaxation of the slightly stretched yarn to form a tail of predetermined length.
Claim 4
Dependent Claim 39 words
A device according to claim 2 in which the carrier for the packages rotates in a vertical plane, the packages extend horizontally, and the means for raising lowering the packages are cam means attached to the knitting machine frame.
Claim 5
Dependent Claim 63 words
A device according to claim 1 in which the intermittent tensioning or gripping means for the yarn are a pair of discs spring urged against each other and a rod with a wedge-shaped end and cam means attached to the knitting machine frame to move the rod up and cause the wedge to move the disc apart thus relieving pressure on the yarn.
Claim 6
Dependent Claim 64 words
A device according to claim 2 in which the intermittent tensioning or gripping means for the yarn are a pair of discs spring urged against each other and a rod with a wedge-shaped end and a cam means attached to the knitting machine frame to move the rod up and cause the wedge to move the discs apart thus relieving pressure on the yarn.

References Cited (Backward Citations)

US2290628A Cited
US3364701A Cited
US3303671A Cited
US3636731A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-10-13 1979-04-14 1979-10-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-10-13 1983-04-14 1983-10-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-10-13 1987-04-14 1987-10-14 $7700.00 Window Closed / Lapsed

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