US2649864A - Attachment for weaving high density fabrics - Google Patents

Description

M. MAYER, JR., ETAL ATTACHMENT, FOR WEAVING HIGH DENSITYFABRICS F iledApril 24. 1951 Aug. 25, 1953 3 Sheets-Sheet l lNVENiORS M.MAYER JR. G.J.KYAME ZJfl-MW ATTORNEY Aug. 25, 1953 M. MAYER, JR, ETAL ATTACHMENT FOR WEAVING HIGH DENSITY FABRICS Filed April 24, 1951 V s Sheets-Sheet z m r R mJ WR E Y A M ATTORNEY Aug. 25," 1953 M. MAYER; JR.. EI'AL 12,649,864

ATTACHMENT FOR WEAVING HIGH DENSITY FABRICS J5 Sheets-Shegt 3 Find April 24, 1951 JQVENTORS M.MAYER JR. G.J.KYA ME {my W ATTORNEY Patented Aug. 25, 1953 ATTACHMENT FOR WEAVIN G HIGH DENSITY FABRICS Mayer Mayer, Jr., and George J. Kyame, New Orleans, La., assignors to the United States of America as represented by the Secretary of Agriculture Application April 24, 1951, Serial No. 222,726

(Granted under Title 35, U. S. Code (1952),

sec. 266) 4 Claims.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes throughout the world without the payment to us of any royalty thereon.

This invention relates to weaving. More particularly it provides a new method of weaving which produces fabrics having a smoother look and feel than those produced by the processes of weaving heretofore known. The new method is capable of producing denser fabrics than can be produced by the processes of weaving heretofore employed. In addition, the invention provides an apparatus which is capable of mechan cally weaving by the new method, and which is suitable for mounting upon any loom.

It is old in the loom art to produce special effects in cloth by applying variable tensions to the warp yarns during weaving. For example, a cover may be produced on the cloth if the warp yarns forming one of the shed layers are given a greater tension than the remaining yarns as the lay beats up. The means heretofore used for obtaining the added tension in the warp yarns are varied. Frequently the tension is obtained, to a certain extent, by raising the whip roll and the sand roll or breast beam, but these methods are not always satisfactory or practical. For over twenty years it has been known that cover could be obtained by attaching to a loom an apparatus embodying a bar extending transversely across the warp strands, close to the shed harnesses, which bar deflected from their normal approach to the shed harnesses the warp strands, at the time they are pulled into shed layers by the harnesses. However, while by such means, for certain weave patterns, all of the warp strands are, in the consecutive deflecting motions of the bar, deflected by the .bar'; different additional tension is applied to part of the warp strands to which additional tension is applied. For example, since the shed harnesses are arranged in banks and some banks are closer to the deflecting bar the warp strands running through the closest banks of the shed harnesses receive the greatest additional tension for a given distance of deflection.

In the above and other means heretofore used for applying variable tension to the warp yarns during the weaving, the resultant fabrics occasionally had a greater density than would have been obtained in the absence of the application of the additional tension. However, the majority of the fabrics so produced were characterized by their lack of uniformity which was the purpose for which the tension was varied. In addition,

the increase in fabric density was slight because the occasional variation in the tension resulted only in an occasional closer packing of the threads into the fell.

We have found that if during the process of weaving. the war strands are divided into two groups each of which contain half of the total number of strands as well as half of the strands passing through each two consecutive dents in the reed, and an additional tension is intermittently applied substantially uniformly upon all of the strands in one group and then upon all of the strands in the other group, with additional tension being applied at the moment of extreme beatup and at least partially released between beats, and with the additional tension being applied so that the warp strands approach the shed harnesses without substantial deviation from the normal warp line; the fabrics produced are unobviously and advantageously different from fabrics of the same composition produced by the same loom without such a synchronized uniform application ofintermittent additional tension.

In contrast to the fabrics produced by the application of variable tensions during weaving, as heretofore practiced; the fabrics produced by the synchronized uniform application of intermittent additional tension (i. e. produced as described in the preceding paragraph) have a smoother look and feel than do fabrics of the same composition woven by the methods heretofore known.

In addition, the density of fabrics woven with a synchronized uniform application of intermittent additional tension is not solely dependent upon the mechanical limitations of the weaving equipment (as is the case in the methods of weaving heretofore employed), but is governed substantially completely by the physical characteristics of the yarn and cloth construction. Particularly when the maximum application of additional tension is synchronized to occur at the instant of extreme beatup; fabrics of abnormally high density can be produced. Such fabrics without chemical treatment or coatings of any kind, are highly resistant to penetration by liquids or gases.

Among the objects of the present invention is the provision of an apparatus which can be attached to any loom, and when so attached, is

' capable of accomplishing the synchronized uniintermittent additional art from the following description, illustrations, and examples of embodiments of the invention.

Fig. 1 is an oblique view showing the components of the attachment and their location relative to each other and to the loom.

Figures 2a, 2b and 2c are general schematic views of the attachment in the neutral position, and in two successive beatup positions.

Fig. 3 is a schematic view showing how the stroke of the warp tensioning member can be reduced.

Fig. 4 is a plan view showing another means for actuating the warp tensioning member.

In the preferred embodiment, Fig. l, a push bar I, preferably one having rounded top and bottom edges, separates warp l6 into two layers, 2 and 3, respectively. Each of the layers contains, hal of the total number of warp strands and half of the strands passing through any two consecutive dents in the reed. A loading member such, as loading bar 4, which is a smooth flat plate having a centrally located aperture, which is preferably one which closely fits the push bar and restricts its vertical motion, yet, permits, free passage of said push bar therethrough, is fitted on push bar I. The overall length, of plate 4 is preferably such that it extends. as far above and below the push bar as is necessary to prevent linking members, such as I2, from contacting the warp, i. e. layers 2 or 3. A slotted member, such as slotted bar .is fittedaround push bar I. Member 5 is a smooth flat plate which is slotted to receive push bar I, The overall length, of; the slot is at least twice the totalvertical; distance traversed by the push bar plus the; vertical dimension of the bar. The lower ends of said, members 4, and 5 terminate in adjustable connecting members, such as threaded connecting rods If} which screw into one end of turnbuckles II, while the upper ends terminate in connecting members, such aschain connectin links; I2 Flexible members, such as chains I3supportedfrom idler sprockets Mwhich are rotatably attached to superstructure I5, are connected tov links I2, thereby positively linking members 4 and5 to eachother. Attached to the lower ends, of turnbuckles II are connectingrods I! which, in turn, are pivotally attached to one end of actuating members, suchaslevers 8 and 9. The other endsv of; said. levers are pivotally attached to supports such as I8which are fitted to a supportmount such,as. I9. Cams Band '1' are rigidly mounted on the loom camshaft 2a and make contact with cam follower. rolls 24 on levers 8 and 9;, to, transmitflpowerfrom said camshaft to said levers. Spaced compensator bars 22-are clamped in clamps 23 supported by brackets 2-4. Mounted on clamps 23 are push bar guides 25 which limit the lateral movement of push'bar I.

The loom is preferably powered by a single motor in the conventional manner, and in such an embodiment, camshaft 20, shuttle harnesses 3fi and lay, sword 34 move synchronously and the relative time of occurrenceof their various functional motions is. adjustable-in the conventionalmanner. In. a particularly preferred embodiment' of the present invention the harnesses are adjusted to form a closed shed at'the-moment, of extreme beatup of lay sword 34 and cams Band I are positioned so that push bar I applies the maximumadditional tension to-one shed layer at the same moment, and-applies such tension to the other. shed layerat the-instant the reed is in the extreme beatup position on the next stroke of the lay sword.

In placing the attachment on a loom, a particularly suitable arrangement is one which will permit loading push bar I (via load members 4) to be at, or as near as possible to, the so-called quarter points, i, e. one quarter the distance from each end of said bar.

As shown in Fig. 2a, warp I6 is threaded through the loom in the conventional manner: from the warp beam 25 over whip roll 28, through drop wires 29, harnesses 3i), and reed iii to the fell 32- of the woven fabric 33. The presence of the attachment on the loom does not in any way interfere with the threading up operation since it is so designed that those parts which would interfere can be readily dismantled and reassembled after the warp is in place. Thus, with the warp in place, compensator bars 22 are clamped in position, one over and one under the warp, and loading members 4 and 5 are brought up through the warp in line with chains I3, and connected thereto through. links I2. Warp I6 is then separated into two sheets to form shed layers 2 and 3 in the immediate vicinity of the aforementioned members. 4. and 5. Push bar. I isinserted between. said shed layers and through members 4 and 5. Guides 25v are then installed.

It isessential that one half. of the warp strands passing through any two adjacent dents of the reed be put in the same layer of war strands passing above or below push bar I. All ofv the strands passing through a given, dent. may be in the same layer, thus, thegroups in alternate dents of reed 3I will all be in the same shed layer and will subsequently be on the same side of the push bar. A particularly preferred: arrangement for the weaving of an oxfoldv or plain fabric isto have half of the strands passing through each, dent in the reed in the same layer above or, below push bar I.

Cams 5 and I are preferably set out of phase with each other, and areadjusted so that push bar I reaches its extreme position, either upward or downward, when loom lay sword 34 is at its extreme forwardor beatup position. Although the camsshown arecircular and rotate eccentrically, they neednot be so limited. Other cam shapes can be used provided they impart to said push bar one upward and-one downward stroke with each revolution of. loom camshaft 2B:

In Fig. 2a, the cams 6, I, and; levers, 8, 9, are shown in the neutral position, in which case, push bar, I preferably exerts no pressure-on either; shed layer 2: or 3; Lay sword 34' is in. its rearmost. position and harnesses 30. have formed a shed 35 through which shuttle 3B is traveling to insert weft thread.3:l. As the loomoperates, lay sword 34 advances causing reed:.3'I= to push weft 3'! toward fell 32 of fabric 33. Meanwhile, cams 6 are pushing levers 8 downward causing push bar I to exert pressure on shed layer 3 thereby placing the warp strands in said shedlayer under extreme-tension.

At this timeshed layer 2 is preferably completely relaxed as-shownin Fig. 2b; As laysword 34reaches-itsforwardmost position, reed 31 beats weft- 31 into fabric 33. slackened warp strands in shed layer 2= over or underthe previouslypicked weftthread. As-the loom operation-continues, lay sword 34 retracts,- cams I push down-onlevers 9 which, through the depending action ofloading members 5- and chains I3, return push bar I to its neutral position. Harnesses 30 form' a reversedshed' 35 and shuttle 36 returns therethrough-to insert. another pick (Weft 31).

As lever 9 continues downward it preferably Weft 37'- thus forces the causes push bar I to leave shed layer 3 and produce tension in shed layer 2 as shown in Fig. 2c. The tightening of said shed layer draws the previously mentioned overriding or underriding weft thread into the plane of the fabric, while the new weft 31 forces warp strands from shed 3 over orunder the pick just described. Lay sword 34 again retracts, lever 8 moves downward pulling push bar I to its neutral position, harnesses 30 form a normal shed, and the above described cycle is ready to repeat.

Compensator bars 22 are placed in close proximity to drop wires 29 and prevent any substantial movement of the warp out of the plane of the normal warp line. Another important function of said compensator bars is to reducethe amount of vertical movement of push bar I required to develop a given amount of tension in the warp shed layers. Thus. while not always necessary, it is desirable to have a second pair of such compensators on the opposite side of the push bar; this arrangement is shown in Fig. 3.

The amount of stroke of push bar I required for weaving a high density fabric is dependent on the physical characteristics of the yarn used and on-the fabric construction. Turnbuckles II allow the regulation of said stroke by controlling the amount of slack inchain linkage I3, thus permitting the utilization of the total throw of camsB and I, or any fractional part thereof. Springs 21 take up the slack in chains I3 thereby maintaining the vertical alignment of loading members 4 and 5 and preventing warp damage which would otherwise occur if loa- d members 4 and 5 are free to slip around.

The invention is not limited to the particular apparatus described above. For example, load members 4 and associated cams, levers, etc. may be positioned so as to apply load to push bar I at its extremities or' any other intermediate points without deviating from the spirit of the invention. The same may be said for slotted member 5. A further variation would consist in making such arrangements as to cause slotted member 5 to function outside the confines of warp I6, in which case said load member would be omitted and chain I3 would be extended to join corresponding connecting rod I0.

Another modification of the invention shown in Fig. 4. In this arrangement cranks 39, fixed to the ends of jackshaft 40 are driven from loom camshaft through suitable driving means such as a gear train, chain and sprocket drive, etc. Crankpins 4 I, adj ustably mounted on cranks inload members 4. The vertical component of the rotary motion of crankpins M is transmitted by connecting rods 42 to load members 4 and hence to push bar I. Guides 43, similar to guides 25 in the preferred embodiment, restrict push bar I to vertical motion only.

Tests have proven that our invention utilizes to the fullest extent the compressibility of the yarn. For example, in the case of the first fabric listed in Table I below. attempts were made to put in more than 72 picks per inch with the attachment providing synchronized uniform application of intermittent additional tension, i. e., to put in 76 and 78 picks. But in each case, pick counts made on the fabrics after weaving revealed that they contained, as recorded, not more than '72 picks per inch. This indicates that the limit of compressibility of the yarn was reached at '72 picks per inch. Without said attachment on the 100m it was found that with gears for the production of more than 56 picks per inch, the operation resulted in an abnormal number of end breaks, thus in impractical operation. I

Data so obtained for typical fabric construe tions are given in the following table; the yarns used were cotton yarns and were woven into an Oxford pattern. In the weavings conducted in accordance with the process oflthe invention the two groups containing half the total warp strands also contained half of the warp strands passing through each dent in the reed, the maximum additional tension was applied and the harnesses formed a closed shed, at the instant of extreme beatup.

The high density fabrics woven by the process of our invention are extremely resistant to penetration by liquids or gases as may be seen in Table II, which gives data for the permeabilities of the above fabrics having the maximum density weavable with and without the use of our 39, actuate connecting rods 42 which terminate invention.

Table II 'lh d Fabric tea 00mm Weight A1r Water P are are Invention Warp Filling yd. 1 Y No. used State Threads per in M1 124 50 9. 20 0184 9. 05 1, 14 124 72 10. 10 0171 32. 82 15. 9 12s 56 9. 37 0171 9. 1, 845 130 10 10. 20 0164 28. 07 108 124 53 9. 00 0181 11. 4a 249 as 10. 34 0173 42. 35 4. 2 12s as 9. 05 0162 10.47 1, 005 67 10. 24 0101 30. 28 103 122 53. 5 9. 03 0175 10.80 265 122 70. a 10. 47 0168 5s. 50 0. 14 124 63 s. 80 0104 s. 45 1, 391 122 71 10. 34 0150 32. 47 s. 5

1 Time required for 300 cc. of air under constant pressure to pass through an orifice covered with the fabric.

1 Volume of water leaking through an 8 x 8 inch fabric sample subjected to the h drostatlc ressure of a water column of constant height for 6 minutes. y p

A lain weave cotton fabric" composed of warp yarn of 36 72" and weft yarnof 18 72 was woven with 64- picks per inch in accordance with the processor the invention in the same manner as the above fabrics. The fabric was subjected to the ASTM drop penetration test (the amount of leakage, in 3 hours, through a fabric mounted on a 45 angle under a constant stream of water from a shower head 8- ft. above the fabric) leakages of 8 cos. and 0 cc. were observed in tests of the untreated fabric. Under the ASTM Suter hydrostatic head test, a head of 74.7 cm. was required-- tocause the first three drops to form on the opposite side of the fabric.

The above fabric was mildew proofed in the conventional manner (causing its hydrostatic head test to increase to 76.5 cm.) and was exposed for two:- months to the semi-tropical weather in the vicinity of. New Orleans, La. When the exposed fabric was again: subjected to the Suter hydrostatic head test, a head of 912.3 cm. was required to. cause the fist three drops to appear. The drop penetration test resulted in no penetration. The impermeability properties of the" fabric hadmarkedly improvedupon weathering.

Having thus described our invention,,we c1aim-:

L In a loom having a warp beam, whip roll, drop wires, shuttle harnesses, shuttle lay sword and reed provided with dents, and a loom camo shaft for operating movable parts, the apparatus comprising: a horizontal push bar slidably mounted so that it is free to move in a vertical direction, but not in a horizontal direction, and positioned behind the drop wires so that it divides the Warp strands into two groups each containing half of the total number of strands and half of the strands passing through each consecutive two dents in the reed; two elongated fiat loading bars centrally pierced to receive and hold said' push bar, so that the push bar is: free to: move horizontally but not vertically with respect to the loadingv bars, positioned with their width parallel to the warpstrands andextending above and below said strands further than saido loading bars move; a chain passing from each of said load bars over an idler sprocket mounted on a loom superstructure to an elongated slotted flat bar positioned with its width paralleling the fiber strands and slottedtoaccommodate the travel of the push bar; cam actuated levers pivotally' attached to the said loading and slotted bars through adjustable rigid connecting memhas and mounted below the loom cam shaft; cams rig-idly attached to the 10cm camshaftpositioned to lower one of said levers the-same distance the other is allowedto rise; and horizontal guide bars rigidly mounted above and below the warp strands both of the aforesaid groups and mounted between the said push bar and the drop: wires so that all of the warp strands are held substantially in the planeo'fthe normal warp line:-

2. In a loom having the standard loomparts comprising whipro'll, shuttle harnesses, lay sword and ree'd' providedwithdents, the apparatus which comprises: a vertically movable horizontal push bar dividing the warp strands into two groups each containing half of the total number of strands and half off the strands passing through every two consecutive dents in the reed; a cam driven. push bar actuating. mechanism arranged to raise and: lower the push bar sothat the warp strands passing above and below the. push! bar arerespectively deflected asthe reed reaches each extreme: beatup position; and two horizontal bars rigidly mounted transversely above and: below thewarp strands and positioned between the push bar and the-drop'wiressothat the deflection imparted to thewarp strands doesnot deflect the strands from the plane of the normal warp line as they pass forward along the-loom.

3a The apparatus ofcl'aimZ with the eamzdriven push ba-r' actuating mechanism synchronized with the loom functions so that the pushbar reaches its maximum vertical travel and the harnesses position the shed layers substantially in parallel at the instant of extreme b'eatup.

4-.. The. apparatusof claim=2 in which two horizontal barsrigidly mounted: transversely above and below the warp strands are positioned between the push bar andthe whip roll in addition to-thetwo-horizontal bars positioned-between the push bar and drop: wiresr MAYER MAYER) JR. GEORGE J.

References Cited inthefile of this patent- UNITED STATES PATENTS Number Name Date 76333628 Petersen i June 28', 1904 1,294,809 Johnstone Feb. 18-,, 1-9-l9 1349;1'2-3' Benson Mar. 4, 1930 1,874,320 Liparif et al Aug. 30-, 1932 2,556,055 Bahan June 5; 1951

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