US2745281A

US2745281A - Device for measuring the unwinding tension from a textile yarn package

Info

Publication number: US2745281A
Application number: US362344A
Authority: US
Inventors: Vincent John Joseph; Wolfenden Philip Hunter
Original assignee: British Cotton Industry Research Association
Current assignee: British Cotton Industry Research Association
Priority date: 1952-06-19
Filing date: 1953-06-17
Publication date: 1956-05-15
Anticipated expiration: 1973-05-15

Description

May 15, 1956 J. J. VINCENT ET AL 2,745,281

DEVICE FOR MEASURING THE UNWINDING TENSION FROM A TEXTILE YARN PACKAGE Filed June l7, 1955 INVEPITORS'.

IFoHH TosePH VINCE/YT AND HIL/p HUIYTE'? h/OL-FET/DE/l United States Patent DEVICE FOR MEASURING THE UNWINDING TENSION FROM A TEXTILE YARN PACKAGE John Joseph Vincent, Wilmslow, Chester, and Philip -Hunter Wolfenden, Manchester, England, assignors to The British Cotton Industry Research Association, Manchester, England, a British research association Application June 17, 1953, Serial No. 362,344

Claims priority, application Great Britain June 19, 1952 11 Claims. (Cl. 73143) This invention relates to an improved device for measuring the unwinding tension from a textile yarn package, and is particularly, though not exclusively, applicable to the measurement of the unwinding tension of yarn from a package in a shuttle.

It is well known that control of weft tension is an important factor in the production of high quality woven textiles, and that considerable variations do in fact exist in the tension in the yarn as the weft is laid by the shuttle. Variation in the unwinding tension of packages other than weft packages may be equally important to other sections of the textile industry.

Measuring devices are known, by means of which the unwinding tension of yarn from a package, for example from a pirn in a shuttle, may be ascertained. Such devices work on the assumption that measurements obtainable from a stationary package, from which the yarn is drawn off at a constant lineal speed, are an indication of tension conditions likely to occur during actual weaving. These machines usually measure the tension arising from all causes, including those of uncoiling resistance, various drag devices and the resistance of the shuttle eye, and the use of these instruments has shown that the unwinding tension from a shuttle varies with the chase of the wind, as well as increasing steadily as the unwinding progresses towards the base of the package. It is the presence of the rapid fluctuations due to the chase of the wind which has hitherto necessitated the employment of a complicated and relatively expensive indicating or recording device.

Such unwinding tension measuring devices as have so far been evolved are more suitable for laboratory or other research work than for general use in a weaving shed or spinning mill, and the object of the present invention is to provide an unwinding tension measuring device which is of simple, cheap and robust construction, requiring a minimum of skill to operate, but which at the same time will give readings of immediate practical value.

According to the invention an unwinding tension measuring device, for a yarn package, comprising a holder for the package and means for drawing off the yarn at a predetermined uniform speed, is characterised by yarn tension measuring means comprising a body of substantial mass, resilient mounting means for said body providing a long natural period of vibration and providing resistance to displacement in counterbalance with the yarn tension, and means for indicating displacement of the said body, whereby a tension indication is obtainable which is substantially a mean value, at any stage, of the unwinding tension of the package.

with the effect of the long natural period of vibration, in

providing the desired readings.

The accompanying drawing is a diagrammatic illustration of one example of an unwinding tension measuring device made in accordance with the invention.

In the example of the invention shown in the drawing for measuring the unwinding tension of; weft in a shuttle the device comprises a holder a in the form of a cradle having a shelf a in which the shuttle rests, and an end'wall a forming an abutment for the nose of the shuttle. The holder is suspended from a pair of long parallel steel strips b attached at their upper ends to The expression mean value is used above to define a suitable anchorage in the form of a top rail 0 so as to be suspended in front of a vertical surface, such as against a wall and so that the holder is suspended in the manner of a pendulum and adapted to swing to-and-fro (leftto-right on the drawing) parallel to thesaid surface with a centralising or" restoring force provided partly by the resilience of the steel strips b but mainly by the force of gravity. The spring strips b are rigidly attached to the holder a andto the anchorage c and such manner of suspension obviates any frictional resistance to move-- ment and provides substantially parallel motion for the holder. Attached to the under side of the holder is a fine toothed ratchet d which may conveniently be provided by a hack-saw blade, and mounted on the vertical face is a back plate 2 carrying a pawl f loaded by gravity or by a light spring into contact with the ratchet. The direction of the ratchet and the pawl is such as to allow diplacement or the holder only-in the direction of the pull of the yarn is to the right in the drawing. Attached to the holder is a pointer g complementary to a scale it at tached to the same back plate andcalibrated to give readings of the force required for displacement.

Adjacent to the device is an unwinding mechanism, preferably including variable speed mechanism whereby the yarn may be drawn from the shuttle in a horizontal direction and parallel to the vertical face at any desired of gravity and resilience of the spring strips [2. Oscilla; tion is prevented by the non-return action of the pawl and ratchet a. The displacement of the holder atiany moment as indicated by the pointer against the scale a function of the displacing force against which it is balanced. The device is not responsive to the rapid variations of tension due to the oscillation of the yarn guide during the winding operation, but gives a reading which. at any stage of unwinding isa mean value oflthej un winding tension over the chase cycle. This is arranged by constructing the instrument in such a wayas to have a natural period of vibration, very long compared with that of the tension variations with the chase. The pawl and ratchet prevent other ramdom oscillations aiiecting the instrument, and at the same time allow the recording of' any steady, or steadily increasing, mean tension.

An instrument of this kind is'useful for: 1. Providing information on the design of the inter'nal fittings of shuttles and on the determination of the most appropriate parts of the internal walls of the shuttle to line with fur or lambs Wool, and to investigate the effect of tuning to control the unwinding of continuous fila-' ment and highly twisted yarns. v

2. Providing means of standardising the unwinding tension from the shuttle is of multi-shuttle looms or shuttles from different looms weaving a similar cloth.

I 3. Providing information on the changes'imunwinding tension which accompany changes in. the; settings of shuttle-eyes. fitted with tensioners. of. any" sort;

. 4.;Providing ;means of standardising. unwinding tension ingeneral.

While described above the. particular. reference to the measurement of. the unwinding tension of aweaving'package in a shuttleQthe device may of course be used or modified for'use tormeasure. the. unwinding tension. of any other package, such as the bobbin for a .sewing machine S t e- Whatweclaimis:

' l. An unwinding tension-measuring device for a yarn packagecomprising a'rbody of substantial mass, resilient mounting means for said body providing. a long natural period of vibration, said mounting. means permitting, but

1 resiliently opposing displacement of said body in a predetermined. direction, means for indicating displacement of said body from anormalzero. position, a holder on said body for a yarn p ackage,.means. for drawing oil the yarn therefrom. at a predetermined uniform speed and in a direction such thatt-he tensionin the yarn has a component in the direction of displacement, of the body, and nonreturn-means in association with the. body to check its returnmovementand thereby assist, in combination with rnounting means. including means. resiliently opposing movement of said yarnholding'meansin said predetermined direction; and meansfor indicating the displacement of saidyarnholdingmeans. in said predetermined direction against-the action; of said resilient means during.

pulling bysaidpullingmeans. 3. Apparatus for measuring the tensile force necessary' to. draw. a yarn from 'a yarn holding means comprising, in combination, a fixed support; means connected to said support for mounting said yarn holding means for movement in a predetermined direction relative to said support; means for pulling the yarn from'said. yarn holding means ihsaid predetermined direction While supported by said support, such pulling of the' yarn resulting also in pulling of'the entire yarnholding means due to resistance of said yarn to-removal from said" yarn'holding means, said mounting means including means resiliently opposing movement of said yarn holding means in said predetermined direction; means for indicating thedis'placement of said yarn holding. means in said predetermined direction 1* againstthe action of said resilient mean during pulling by said pulling means; and means for preventing said yarn holding. means from moving in a direction opposite to said predetermined direction.

4'. Apparatus for measuring the-tensile'force necessary to'draw a yarn from a yarn holding means comprising, in

combination, a fixed support; means for mounting said yarn holding means; resilient means connecting said mounting means to said supportto permit movement of said-yarn holding means in a predetermined direction relative to said support, said resilient means tending to resiliently oppose movement of said yarn holding means in said'predetermined' direction; means for pulling the yarn from said yarn holding means in said predetermined direction while mounted on said mountingmeans, suclr,

pulling of the. yarn. resulting also in. pullingof theenn're yarn holding means due to resistance of said yarn'to removal from said yarn holding means; and means for indicating the displacement of. said yarn holding means in said predetermined direction against the action of said resilient means during pulling 'by said pulling means;

5. Apparatus for measuringthe tensile force necessary to draw a yarn from a yarn holding means comprising, in combination,- a fixed support;- means for .mounting said yarn holding means; resilient means'connecting. said mounting means to said fixed support to permit movement of said yarn holding means in a predetermined direction relative tonsaid support, said resilient means site to: said predetermined direction while said yarn is being pulled; from saidyam holding means. a

6. Apparatus for measuring the tensile force necessary to draw a yarn fromzayarn holding means comprising, in comhination a fixed support;.means connected to said support for. mounting said yarn holding means for movement. in: a predetermined direction. relative to said sup- Q port;.means for pulling the 'yarn from said yarn holding means in said predetermined: direction while supported by said support, such. pulling'of the yarn resulting also in pulling of theentire yarn holding means due to. re-

sistance ofi SaidJyaIn to: removal from. said yarn holding means, saidimounting meansrincluding means resiliently opposingmovement; of said yarn. holding means. in: said predetermined direction; means for indicating the dis placement'ofisaidkyarn' holding. means in said predetermined directiornagainst the action of said resilient: means during pullingrby said: pulling means a" ratchet fixedly connected to said yarn holding means; and a pawl mounted on said support adapted. to. engage saidratchet and prevent said yarn holdingrmeans from IIIOVlIIg.lXlJ.2l: direction opposite to said predetermined. direction while i said yarn is being pulled: from. said yarn'holding means.

7. Apparatus for, measuring the tensile force necessary" to draw. ayar-n ;f-rom .a' yarn-holdingmeans comprising, in

combination, a; fixed? support; means connected to said support for mounting; said: yarnholding" means feirmovement in. a predetermined direction'relative to said support; meansfor. pulling tlie' yarn' from; said: yarn holding means .in..-said-Ipredetermined direction while" supported:

holding means. in said. predetermined direction against:

the action. of said resilient means during pulling by said pulling means,

8. Apparatus forfmeasuringthe tensile force necessary to'draw a yarn from a yarn holding. means comprising, in combination,afixedsupport; means connected to said support formountingsaidfyarn. holding means for. movement in a predetermineddirection. relative. to said support; means for pulIingtheyarnfrom said yarn holding means in said'predetermined; direction. while supported by said support, suclipulling oftlie yarn resulting also in' pulling of the entire'yarnholding means'due to resistance of said yam to removal from said yarn holding means, said mounting means including means resiliently opposing movement of said yarn holding means in said predetermined direction, said resilient means having a long natural period of vibration; and means for indicating the displacement of said yarn holding means in said predetermined direction against the action of said resilient means during pulling by said pulling means.

9. Apparatus in accordance with claim 4 wherein said resilient means include thin parallel spring-like members which provide progressively increasing resistance to displacement and also provide a frictionless and substantially parallel motion for said yarn holding means.

10. Apparatus in accordance with claim 4 wherein said mounting means and said resilient means are arranged so that the yarn holding means is suspended as a pendulum to provide resistance to displacement.

11. Apparatus for measuring the tensile force necessary to draw a yarn from a yarn holding means comprising, in combination, a fixed support; means for mounting said yarn holding means, said mounting means having a substantial mass; resilient means connecting said mounting means to said fixed support to permit movement of said yarn holding means in a predetermined direction relative to said support, said resilient means tending to resiliently oppose movement of said yarn holding means in said predetermined direction; means for pulling the yarn from said yarn holding means in said predetermined direction while mounted on said mounting means, such pulling of the yarn resulting also in pulling of the entire yarn holding means due to resistance of said yarn to removal from said yarn holding means; and means for indicating the displacement of said yarn holding means in said predetermined direction against the action of said resilient means during pulling by said pulling means.

References Cited in the file of this patent UNITED STATES PATENTS 1,911,006 Valentine May 23, 1933 2,092,439 Bouhuys Sept. 7, 1937, 2,407,545 Fish Sept. 10, 1946

Claims

1. AN UNWINDING TENSION MEASURING DEVICE FOR A YARN PACKAGE COMPRISING A BODY OF SUBSTANTIAL MASS, RESILIENT MOUNTING MEANS FOR SAID BODY PROVIDING A LONG NATURAL PERIOD OF VIBRATION, SAID MOUNTING MEANS PERMITTING, BUT RESILIENTLY OPPOSING DISPLACEMENT OF BODY IN A PREDETERMINED DIRECTION, MEANS FOR INDICATING DISPLACEMENT OF SAID BODY FROM A NORMAL ZERO POSITION, A HOLDER ON SAID BODY FOR A YARN PACKAGE, MEANS FOR DRAWING OFF THE YARN THEREFROM AT A PREDETERMINED UNIFORM SPEED AND IN A DIRECTION SUCH THAT THE TENSION IN THE YARN HAS A COMPONENT IN THE DIRECTION OF DISPLACEMENT OF THE BODY, AND NONRETURN MEANS IN ASSOCIATION WITH THE BODY TO CHECK ITS RETURN MOVEMENT AND THEREBY ASSIST, IN COMBINATION WITH THE EFFECT OF THE LONG NATURAL PERIOD OF VIBRATION, IN PROVIDING THE DESIRED READINGS.