US2419829A - Woven fabric reinforcement - Google Patents

Description

April 29,1947. w, FRAIM wovEN FABRIC REINFORCEMENT Filed May 15, 1944 INVENTOR- i'fi'ae/w n m/ l'cvxm ATTORN EYS Patented Apr. 29, 1947 WOVEN FABRIC REINFORCEMENT Freeman W. Fraim, West Barrington, R. I., assignor to International Braid Company, a corporation of Massachusetts Application May 13, 1944, Serial No. 535,421

8 Claims.

This invention relates generally to the reinforcing of a woven fabric and especially to reinforcing a parachute fabric. It has particular reference to the manufacture of reinforcing braid to increase the load-carrying capacity of the woven sail or canopy of a parachute.

All textile materials in being loaded have a definite elongation characteristic dependent upon the type of fiber used and the construction of the fabric. When two dissimilar constructions of fabric each made of a different fiber are tightly joined as by sewing, the problem of causing each fabric to sustain its own proportion of the load is complicated by many factors.

Heretofore, it has been practically impossible to sew a highly dimensionally unstable braid to a more stable Woven fabric and have both fabrics or members exhibit the same elongation characteristics before rupture. Even so, it has been considered desirable to sew a coreless unstable braid to a parachute formed of woven cloth for reinforcing the same.

One of the objects of this invention is to provide a braided cord which when sewed onto a woven cloth will have an equal elongation to the cloth so that both units will elongate equally as a whole.

Another object of this invention is to provide the reinforcing braid of novel construction simplifying the problem of balancing the stretch characteristics of the reinforcing member and of a woven cloth.

Another object of this invention is to provide a braided fabric with a known and controllable elongation that can be easily manipulated by unskilled sewing machine operators in attaching the same to a woven cloth so as to have the same elongation as the woven fabric.

Another object of this invention is to provide a parachute in which the maximum strength of the reinforcing braid is obtainable thus resulting in a stronger parachute and. yet one which may be made light in weight and occupy a minimum volume.

Another object of the invention is to provide a braid which will lie generally flat and free from twisting.

More specifically, this invention is to provide a braided fabric which will have a core or warp to definitely provide a reference point as to elongation of the braided fabric which may be used in properly attaching or sewing the braided fabric to the woven fabric.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is a plan view of a fragmental portion of a braided fabric constructed in accordance with this invention;

Fig. 2 is an elevation of a parachute open an showing my reinforcing braid such as shown in Fig. 1 attached to the canopy thereof; i

Fig. 3 is a greatly enlarged view illustrating the position of a core or warp in the fabric of Fig. 1;

Fig. 4 is a sectional view taken substantially 0 line 4--4 of Fig. 2;

Fig. 5 is a diagrammatic view illustrating a portion of the serpentine path of the yarns of the fabric about the core or warp.

In proceeding with this invention I provide a braid woven on a usual form of braiding machine and of generally known construction except that.

one or more members are located in the braid for controlling its axial stretch and which are in-;

equal to the elongation of the material of the woven fabric to which thefinished reinforcing braided cord is to be sewed. The braided cord is then constructed of selected yarns with a deflnite pickage and tension such that its elongation from the point at which the axial control members are taut to rupture will be the same as that of the axial control members. These axial control members therefore contribute to the strength of the cord as a whole and provide a reference point from which the elongation of the entire cord is definite and known. This reference point is that point of elongation where the warp ends becometaut through the application of a certain range of tension. This tension may be easily applied by hand when sewing occurs. Working tension at or beyond the amount to produce this condition is all that is needed to properly handle the finished cord and fabric. A braid constructed in the foregoing manner can readily be handled in a sewin operation where it is applied to a woven cloth by sewing. It is only required that sufiicient tension be applied to make the warp ends become taut since a considerable increase of tension would be required to elongate the warp ends beyond this point.

With reference to the drawings, the braid which I construct is made upona regul'artubular braider with the carriers winding in and out of the serpentine raceways to leave the yarns as H] and II as fragmentally shown in -Fig. -5 in a tubular formation. At diametrically opposite points extending up through posts intwo of the diametrically opposite quoits of themachine, there are cores or warps which are fed up to the maypole of the machine and there assembled in the braid in a locked relation.

The axially controllable members are designated l5 and I6, as shown in Figs. 1 and 3, and are strands of twisted yarn composed of fibers so selectedor prestretchedias to have a fixed elongation from hand tautness to rupture equal to the elongation of the woven material [8 to which the finished reinforcing cord'is tobe sewed.

The braided yarns 25? are provided froma plurality of packages on the braider carriers'which move in and out through the serpentine pathways of a braider so as'to braid their yarnsone about the other'and also about the cores liand i6. By this arrangement the cores l5 and 16- are locked in the braided fabric as cores and'provided axially extending controllable members. The elongation of the braid may becontrolled by changing the icks per inch.

The yarns'which are used in braiding as at 25 maybe of many diiferentmaterials, such for'instance as cotton, rayon, or silk, I. have foundit satisiactoryto use rayon yarn which is composed of a plurality of yarns laid side by side and woven as a group in generally flat form oneabout the other. The. number of yarns and the'tWist gi-ven each will be selected for the strength-"characteristics desired.

In Fig. 2 I have illustrated a parachute consisting generally of a sailor canopy H composed of aplurality of segments I S seWed together along gore lines l9 eachshaped substantiallyalong thearea of a segment of the surface ofthe's pliere. The. fabric in each one ofthe segments l8 -is woven from a light-weight materialof strong construction. The sewing or gore lines I-B ser-ve to reinforce the canopyalong the dire'ction of theirextent. At the'e'dge of: the canopy-20 where the gore lines meet this edgeshroud lines '21 areattached which come to a common point ZZt-o support a load through'thepart designated generally 23. In. order to reinforce this-canopy-the braided cord described'abo've designated generally 241s sewed around the canopy atri'g'ht 'angles'tm The controllable. members wand I6 serve to provide a, definite referencepoint'i for the braided cordso that the braided 'cord. maybe' 'made hand 151 the above construction.

taut at this certain point as a limit in sewing it in position. For this reference point it is known that the characteristics of the braid by reason of prior selection, picking and so forth will be a certain definite amount which will be equal to the elongation from this reference point to rupture of the Woven cloth. Thus when the two are sewed together under the same tautness from this reference point it is known that both members, materials or units will elongate the same from this reference point to rupture and thus each will add to the final product the maximum strength which itapo'sse's'ses.

The parachutemay be packed into a very small space and yet be very strong for its weight due to I claim:

1. The method of reinforcing a woven fabric which consists in selecting a strand having a fixed-elongation from a certain tautness to rupture-eciua'l to the elongation of the woven fabric from a definite tautness to rupture, braiding about said strand a cord formed of yarns so selected as to material and so tensioned that the elongation from the point at which said strand is taut to rupture will be the same'as that of the strand and attaching said cord to the woven fabric to be reinforced with both under their predetermined tautness'as a reference point.

2. A woven fabric having a: braided cord attached thereto, said fabric'and cord both with the same'fixed elongation from a certain tautness to rupture, and'an axial member in said cord serving as a reference point for determining the stretch of said cordat said tautness.

3. A woven fabric havinga braided cord attached thereto, said fabricand cord'both with the same fixed elongation-from a certain tautness to rupture, and an axial member in said cord serving as a reference point for'determiningthe stretch of said cord at said tautness, said member also having the same elongation to rupture from said tautness.

4. A woven fabric having a braided cord at- 1 tached thereto,. said fabric and cord both with the same fixed elongation from a certain tautness to rupture, and a pair of axial members insaid cord serving as a: reference point'for determining the stretch of said. cord: at saidtautness.

5. A woven fabric having a braided cord attached thereto; said fabric and cord' both withthe same fixed elongation from a certain tautnessto rupture, and a pair of' axial members irnsaid cord serving as: a referencet point for determining. the stretch of said cord at saidtautn'ess; said members also' havingJthe same elongation torupture from said tautness.

6. A woven fabric havinga tubular braided cord; attached" thereto; said fabric and cord both with "the same fixed elongation from a certain tautness to rupture; and a pair of axial members in-said cord located at diametrically-opposite points for controlling the-stretch of said c'ord at said-tautness.

7-: A parachutehaving a2 canopy with circular reinforcing cordsi attached theret'm' s'a'id many andcords'both having: the same circulai' el'o'n'gation" from a'certain tautness toz ru'pture and-anaxial member in said cord controlling the stretch of saidcord'atsaid-tautness;

8;"A parachute-having a canopy'of woven fabric with circular reinforcing cords sewed thereto, said canopy and" cords-both having thefsame elongation in the direction'ofsaid cords'froma certain taiit'ness-to rupture and an axial member in said cord controlling the stretch of said cord Number at said. tautness. 2,001,527 FREEMAN W. FRAIM. 2,145,786 2,125,838 REFERENCES CITED 5 1,321,322 The following references are of record in the 770:0 3 file of this patent: 1,194,691 UNITED STATES PATENTS N 2337192 Number Name Date 330,787 Isherwood Nov. 1'7, 1885 Number 1,108,262 Smith Aug. 25, 1914 21,450

Name Date Davison May 14, 1935 Birkmeyer Jan. 31, 1939 Stark Aug. 2, 1938 Lane June 24, 1930 Deming Apr. 28, 1885 Gingras Sept. 13, 1904 Adams Aug. 15, 1916 Hastings Dec. 21, 1943 FOREIGN PATENTS Country Date Swiss May 21, 1901

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