US2689587A - Weaving of textile fabrics - Google Patents

Description

p 1954 w. w. DENNISON ETAL 87 WEAVING OF TEXTILE FABRICS 2 Sheets-Sheet 1 Filed April 18 1951 INVENTORS.

N B U mam M DA D O W. CE T R M M E R AT L WCW Sept. 21, 1954 w. w. DENNISON ETAL 8 WEAVING OF TEXTILE FABRICS v v 2 Sheets-Sheet 2 Filed April 18, 1951 INVENTORS. WILLIAM W. DENN ISON CHESTER C. ABRAMSON WALTER E. DAVIS AT TORN EYS.

Patented Sept. 21, 1954 WEAVING F TEXTILE FABRICS William W. Dennison, West Englewood, N. .L, and Chester 0. Abra-mean, Lavale, and Walter E. Davis, Cumberland, Md., assignors to 'Oelanese Corporation of Americ ,poratinn of Delaware a. New York, N. Y., a col-'- ApplicationApl-il 13, 1951, Serial No. 221,652

This invention relates to the weaving of textile fabrics and relates more particularly to a novel process and apparatus for the weaving of textile such looms are normally equipped to prevent the production of defective fabrics. After correcting whatever conditions necessitated the stopping of the looms, the said looms are started again by the operator to continue the weavin 0f the textile fabrics. The stoppin and starting of th'elooms produces noticeable marks on the woventextile fabrics, which marks are commonly called stop marks or set marks. While these set marksare not too noticeable in certain types of woven textile fabrics and therefore dot not greatly affect their commercial value, they are very noticeable and therefore highly objectionable in other types of woven textile fabrics and the presence of more than 'a very small number of these set marks in apiece of these latter types of woven textile fabrics leads to the downgrading, of said fabrics.

It is an important object of this invention to provide a novel process and apparatus for the production of woven textile fabrics which will be free from the foregoing and other difficulties and) which will beespecially efficient in operation and simple in construction.

A further object of this invention is to provide a process and a paratus for the production of woven textile fabrics substantially free from set marks.

Other objects of this invention, together with certain details of construction and combinations of parts, will be apparent from'the following detailed description and claim.

It has been discovered that when a loom is stopped, the tension on the warp yarns that have" not yet been woven into the textile fabric tends to remove some of the crimp from the warp yarns in that portion of fabric positioned between the breast beam over which the textile fabric passes on its way to the take-up roll, and the fell of the fabric, i. e. the edge or the fabric which is closest to the reed of the loom. When the loom-is started up after having been stopped, the first few picks are over-beaten into the fabric resulting in a tight set mark. Moving of the fell of the fabric to the position it occupied before the loom was stopped does not successfully eliminate the .set

marks although it does reducetheir noticeability' in some types of fabrics.

1 Claim. '(Cl. 139-316) It has been found th t substantially to eliminate all traces of a set mark the fell of the fabric must be moved, before the loom on which said fabric is being woven is again started, to a posi-- tion closer to the reed-0f the loom than the position it occupiedwhen the m was stopped. The precise position to which the fell of the woven textile fabric must be moved before starting the loom will depend upon the nature of textile fabric being woven and of the loom employed in the weaving operation. Howevergin the weaving of many different types of textile fabrics on several different types of looms, the set marks have been substantially eliminated from said fabrics by moving the fell of the fabric, before again starting a loom once it has been stopped, to a position from about 0.060 to 0.090 inch closer to the reed of the loom than the position it occupied before the loom was stopped; the exact distance for any type of fabric bein readily determined by the loom operator. The fell of the fabric may "be positioned at any desired point by rotating the pick wheel of the loom, as is well understood in the art.

Any suitable measuring means may be employed accurately to determine the position the fell of the fabric after thefloom has stopped and before it is again started, which measuring means may, for example, be optical, electrical or mechanical in nature. Optical means have been found to be especially well suited for this purpose since they enabl'ethe fell of the fabric to be magnified to any desired extent so that its position may be determined accurately wi'th a minimum of difficulty. The optical means may comprise a suitable magnifier or microscope mounted to view the fell of the fabric, or an optical projector suitably positioned to cast an image of the fell of the fabric onto a screen. In positioning the fell of the fabric before the loom is started, more reproducible and more accurate results are obtained if the measurement of said position is made, not on the last pick in thefa'bric, but on the pick next adjacent thereto.

While the positioning of the fell of the fabric in the manner described above will substantially eliminate the set marks from the fabric, it has been discovered that "theappearance of the fabric'may be improved even further if the tenstopped without the necessity for special action on the part of the loom operator. For example, means may be provided to release the pawl on the pick wheel when the loom is stopped thereby effectively removing the tension on the fabric and the warp of yarns. In this case, the loom may also be provided with braking means which will automatically engage the pick wheel when the pawl is disengaged therefrom to limit the speed of rotation of said pick wheel and to prevent overrunning of the fabric roll to which said pick wheel is secured.

A preferred embodiment of the apparatus of this invention is shown in the accompanying drawings wherein:

Fig. l is a diagrammatic side elevational view of the loom,

Fig. 2 is a detail view, on an enlarged scale, of

a portion of the loom shown in Fig. 1,

Fig. 3. is a plan view, on an enlarged scale, of a portion of the loom shown in Fig. 1,

Fig. 4 is a detail cross-sectional view, on an enlarged scale, taken along the line 44 in Fig. 3 in the direction of the arrows, and

Fig. 5 is a showing of the field of the microscope when the fell of the fabric is positioned properly.

Referring now to the drawings, the reference numeral I designates a warp beam from which a warp of yarns I2 is drawn under suitable tension over a whip roll l3 which is usually loaded by means of springs, weights, or the like (not shown) From the whip roll I3, the warp yarns l2 are passed through a stop motion device l4 and are then threaded between lease rods IE to separate the yarns into two groups. After leaving the lease rods l5, the warp yarns |2.pass through harnesses l6 which raise and lower selected yarns in any desired sequence to form a shed ll. Positioned in front of the harnesses l6 is'a lay or batten l8 which carries a raceplate l9 and is provided with a reed 2| between the dents of which the warp yarns l2 are threaded. A'shuttle 22, riding on the raceplate l9 and guided by the reed 2|, passes through the shed I! to lay a filling yarn or pick 23 into the said shed. After the shuttle 22 has passed through the shed II, the batten I8 is moved from the position shown in full lines to the position shown in dotted lines in Fig. l of the drawings to beat the pick 23 into its proper position in fabric 24, the fell of which is indicated by reference numeral 25. The fabric 24 then passes over a breast beam 26, around a positively driven sand roll or take-up roll 21, over a guide roll 28 and is wound onto a fabric roll or cloth roll 29. There is provided in the loom a ratchet wheel or pick wheel 30 equipped with a pawl 3 |,'which pick wheel is connected through suitable means (not shown) to the take-up roll 21 and the cloth roll 29 and is driven stepwise in synchronism with the operation of the loom to take up the fabric at the rate it is produced. It is to be understood that the construction and operation of the loom described above is entirely conventional.

When the loom is stopped, either through the operation of the stop motion device l4 or in any other manner, brake arm 32 of the loom will drop from the position shown in full lines to the position shown in dotted lines in Fig. 2 of the drawings and shipper arm 33 of the loom will rotate clockwise about pivot 34 on which it is mounted, all in a manner well known in the art. The rotation of the shipper arm 33 will carry rod 35, which is secured to the shipper arm 33 by means of a bracket 33, into contact with the pawl 3|, releasing the said pawl from engagement with the pick wheel 30 and thereby effectively removing the tension from the fabric 24 and the warp yarns l2. To limit the speed of rotation of the pick wheel 30 and prevent overrunning of the cloth roll 29 when the pawl 3| is released, the brake arm 32 is'provided with a bracket 31 carrying a brake member 38 which will frictionally engage pick hand wheel 39 fastened to the pick wheel 30 when the brake arm 32 drops on the stopping of the loom.

To position properly the fell 25 of the fabric 24 before the loom is again started after it has been stopped, there is provided a measuring means, indicated generally by reference numeral 4|. The measuring means 4| comprises a plate 42 fastened to the breast beam 26, which plate 42 has an arm 43 secured thereto by means of a hinge 44. The arm 43 carries a bracket arm 45 which extends over the fabric 24 and supports an adjustable mount, indicated generally by reference numeral 46, carrying a microscope 41. The mount 45 comprises a lower slide 43 which is fastened to the bracket arm 45 and has a stud 49 projecting upwardly therefrom. An upper slide 5| having a slot 52 extending therethrough is positioned adjustably on the lower slide 48 and is held against movement by means of a knurled nut 53 in threaded engagement with the stud 49. Fastenedto the upper slide 52 is a fitting 54 which carries the microscope 41 and is provided with an adjusting rod 55 to enable the microscope 4! to be focusedsharply on the fabric 24.

In starting the loom after it has once been stopped, the measuring means 4| is moved manually to the position shown in Fig. 3 of the drawings. The pick hand wheel 39 is then rotated by the loom operator to apply tension to the warp yarns l2 and the fabric 24 and to draw the fell 25 of said fabric 24 under the microscope 41 until the pick 23, which is next adjacent to the fell 25, is aligned with the index line 56 as shown in Fig. 5 of the drawings. In this position, the fell 25 is closer to the reed 2| than it was when the loom was stopped. The measuring means 4| is then pivoted about the hinge 44 to the position shown in dotted lines in Fig. 1 of the drawings so that it will not interfere with the operation of.

In a process for the weaving of textile fabrics on a loom wherein the loom is stopped and started again during the weaving operation, the steps of substantially eliminating set marks from the woven textile fabric, which comprises removing tension from the fabric and the warp of yarns when the loom is stopped, whereby due to the release of tension, the fell of the fabric moves towards the reed of the loom, applying tension to the fabric to move the fell thereof in a direction away from the reed to a different position which is between the position occupied by the fell of the fabric after said release of tension and the position occupied by the fell of the fabric when the loom was stopped, said different position being about 0.060 to 0.090 inch from the position occupied by the fell of the fabric when the loom was stopped, and then starting the 100m when the fell of the fabric is in said diiferent position.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Hollins Mar. 2, 1915 Jenckes May 15, 1917 Northrop Jan. 1, 1924 Astle Oct. 13, 1925 Gibbs May 14, 1935 Darwin June 13, 1950 Sprouse May 8, 1951 Gosnell Apr. 1, 1952 FOREIGN PATENTS Country Date Germany Nov. 21, 1929

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