US2287519A - Multiple warp ladder web - Google Patents

Description

June 2 3,

i 'G. F. FRENCH MULTIPLE WARP LADDER WEB a Sheets-Sheet 1 Filed A'pi-il 22, 1938 UN I a a %N H GEORGE RFMH June 23, 1942.

a; F. FRENCH MULTIPLE WARP, LADDER WEB Filed April 22, 1938 3 Sheets-Sheet 2 INVENTOR.

v GEORGE F'FRENGH BY 9+2:

ATTORNEY.

L e. F. FRENCH MULTIPLE WARP LADDER WEB" June 23,1942:

Filed April 22, 1938 5 sneis-sneet s GEORGE E- FRENCH Patented June 23, 1942 UNITED STATES RATE-NT OFFICE 2,287,519 MULTIPLE WARP LADDER WEB George Frederick French, Manchester, .England, as'signor, ,by mesne assignments, to"-R,oger Fre Manchest lan i-en lh mse QnApril-fi, 1938, Serial 203,584

' teile m e 22, 19am 16 cl s. (01. 139 -3s4) This invention relates .to ladder web, as for example, such asisused for supporting thej'l aths of Venetian blinds or for holding pieces of cork or the like in sun helmets. The presentinvention is closely related to that describedin tmy copending application Serial No. 203,583; filed April "22, l938, entitled Triplewarp ladder Web, now Patent No. 2,141,038, dated December 20,

The previously known make of webbing consisted of two lengths-of wide outer webbing, usually called bands or bandings, joined atfintervals by narrow cross-straps arranged in'rdws, one near each edge. The connections of the cross-straps with the bandings consisted of short portions of the warp threads'of'each cross strap superimposed upon and interwoven with affe'w 0f the weft threads of the bandings. 'Theilengths of the connections were at most about 'halfLto three quarters of an inch for thelargest size of webbing, or longest length of strap, and shorter for smaller sizes of webbing, or shorter lengths of straps. Owing to such short connectionsand owing to the strap-warp threads being onlysu'perimposed upon the bandings and only "held thereto by the banding weft, the straps were liable to pull out, -'or become disconnected from the bandings:

The weakness of the connections was further-accentuat'ed by the use of relativel'y' fine yarn for the cross-straps, and especially 'in webbing with short cross-straps; perimpo'sing and weft binding-in method of con nection, plain weave for strength, the joining-sot the cross-strap threads showed through and d-is- In the making of the prior art webbing only,

one lot of warp threads was used to ,weave each O 0f cro r s, c wa p threads .beine continuous for the whole length of the webbing and, a t sstr a w ve bein upe impdsed i l h be d e s n qu d ther o b the banding, wefts, short-free cross warp threads beingleft'between successive bindings-in, which were afterwards "cut 'away to free} thebandings fromleach isniemnereso'jcmed;

' With such make of webbing, each binding-in Moreover, owing to the su-- outer band, a cross-strap, aportion of the opposite outer band, then crossing over to 'the first named outer band, and the cycle is repeated. The present invention utilizesthe principles involved in said applicationandjprovides' further improvements and"'developmen ts which give greater flexibility: in operation and allows considerable variation in the manufacture of ladder Web' I 7 r It is, therefore,among the objects of the present invention to produce ladderwebbing in which, without altering the usual spacing of the crossstraps for a'given width of blind lathand overlap, the'connections of the cross-strap warps withthe outer bandings are lengthened-and strengthened,

and their liability to pullout, or be'comediSconnectedifrom the bandin'gs, thereby reduced to a minimum, if notentirely obviated. A'further object is to make uselof the increased strength of strap-warp connec'tionsto allow of the webbing b'eing produced more cheaply than heretofore, and without the blemishes of the knownfrnake of webbing.

It is still further among-the-objects of the present invention to provide a ladder webbing which allowsof a firmer and stronger connection of the cross-straps with the outer ban'dSQWherein the cross straps may be weftless, narrower outer bands maybe utilized, giving'greater flexibility in the operation of forming ladder web, allowing greater production from a loom,and resulting in a lower cost of production.

As an example of the practice of the present invention, the warp threads of each cross-strap interchange with, or displace a like number of warp threads of one outer band, and'are then interwoven with the other warp threads of the same outer band'foraldistan'ce equalto the distance from the start 0f' such interweaving to a pointwhere theinterweaving of the warp threads of the next strap with the sameouter'band commences. Where the interchange takespl'a'ce, the

displaced band warp threads pass over, in the form of short free warps, to the opposite outer band, when a like number of warp threads of such opposite outer band are displaced, and used to form the next succeeding cross-strap, whilst such displaced warps are replaced by the warp threads of the previous interweaving with the first outer band, after which the third cross-strap is formed. The interweaving of the warp threads of one strap with one outer band, followed by free warp threads extending from such band to the opposite band, then by the interweaving of the same warps with such opposite band, followed by the formation of a cross-strap between the bands, form a cycle, which is repeated throughout the length of the webbing for every first and fourth cross-strap, and the same cycle occurs for each of the two intermediate cross-straps.

In such example, three separate sets of warp threads are used, one for the first and each succeeding first cross-strap, another for the second cross-strap, and a third for the third cross-strap, and so on.

The foregoing description applies to the crossstraps lying in one row and at or near one edge of the webbing, and the same applies to the other row of cross-straps at or near the other edge of the webbing, and, as usual, the cross-straps in one row will usually lie opposite the spaces between the cross-straps in the other row, although, as hereinafter described, the straps in one row may lie opposite those in the other row, or slightly in advance. Or, there may be one row of cross-straps only, especially in the case of webbing for small blind laths. For conveniently giving effect to the foregoing method of connecting the cross-strap warp threads to the hands, a multiple warp-shedding motion will be used.

In carrying out the invention according to a further example, the cross-strap warp threads, after forming a cross-strap, are superimposed upon the warp threads of one outer band and bound thereto by the bad weft in like manner to the usual binding-in, but instead of for a short distance only, for a distance reaching to the binding-in of the next cross-strap warp threads with the same outer band, after which they pass to the opposite outer band in the form of short free warp threads. The same length of strap warp thread binding-in then takes place with such opposite outer band, previous to-another cross-strap being formed, when, after such crossstrap is formed, the cross-strap warp threads are again bound into the opposite outer band, and so on continuously throughout the entire length of the webbing. As in the first example, there will be a cross-strap between the binding-in of the cross-strap warp threads with one outer band of the preceding cross-strap, and the binding-in with the opposite outer band of the warp threads of the succeeding cross-strap. The same operations take place in the formation of each row of cross-straps. In this last described example,

there will also be three sets of cross-strap warp threads.

The cross-strapwarp threads, after being interwoven, or bound-in with an outer band, instead of crossing over immediately, as free warp threads, to the opposite outer band, may then be superimposed upon such band for the distance normally required with the old type of bindingin, thereby giving an additional length of connection as well as reducing the length of free crosswarps and the consequent cutting of such warps to a minimum.

Although preferring that the bindings-in shall be of uniform length, those of one outer band may be shorter than the bindings-in of the other outer band, and in such case (as in the others), the cross-strap warp connections with one outer band may be by the warp-interchange method, and the connections with the other outer band may be by the warp-thread superimposing the weft-binding method. In this example, two sets only of cross-strap warp threads may be used.

As usual, the cross-over portion of the free warps between the bands will be cut away after the webbing is fully formed.

In the accompanying drawings, constituting a part hereof and in which like reference characters indicate like parts:

Fig. 1 is a side elevational view, diagrammatic in character, showing one form of the present invention;

Fig. 2 is a horizontal cross-sectional view taken along the line 2--2 of Fig. 1 with the omission of certain details and also of the cross-over threads, and exaggerating the distance between the outer bands;

Fig. 3 is a view similar to Fig. 1 showing a modification of the invention, wherein the structure of Fig. l is shown in dotted lines and additional structure is shown in full lines; and

Fig. 4 is a horizontal cross-sectional view taken along the line 44 of Fig. 3 with the omission of the cross-over threads.

Fig. 5 is a diagrammatic side elevation of another example of the invention.

Figs. 6 and '7 are side sectional views of portions of one of the outer webbing bands, and show the manner of binding in the cross-strap warps.

Figs. 8 and 9 are diagrammatic sectional plan views of two further examples of the invention.

In accordance with the embodiment shown in Fig. 1, there is provided a weft thread i for the upper outer band, said weft thread being woven continuously into a plurality of sets of warp threads la to form the upper outer band.

There is also provided a set of Warp threads 2 which are woven with weft thread I up to point 3 and the warp threads 2 then cross over at 4, entering the lower outer band at 5 and being interwoven with the weft thread 6 of said lower outer band, the weft thread being continuously interwoven to form the lower outer band. Said warp threads 2 are continued in the lower outer band over an area 1 leaving said lower outer band at 3 and crossing over to form cross-strap 9, and entering the upper outer band at It. The warps 2 are continuously interwoven over the area- H to form said upper band past the point I2 and leaving said upper band at' [3, formingforced section with the first set of warp threads. Said second warp threads 20. continue to the point 22, where they leave the lower outer band, forming cross-strap 23, and entering the upper outer band at point I2, continuing in the same as shown at 24, repeating the cycle. 'I'he'section between points .12 and i3 constitutes a reinforced area.

.A third set of warp threads 25, forming an area of the lower outer band, leave the same at point'Zfi, forming a cross-strap .21, and entering the upper outer band at point 28 and continuing therein over the area 29. .The section between points .28 and I8 constitutes a reinforced area. Said warp threads25 leave the upper outer .band at point .35, forming the cross-over 31. The section between points ill and3ll constitutes a reinforced area. Said threads then enter the lower outer band at point 32, and are woven in over an area 33, thus repeating the cycle. The section betweenpoints 32 and .22 constitutes a reinforced area.

Said reinforced areas serve not only for the purpose of strengthening the entire structure, but they also have the effect of providing a ladder web in which the spacing of the severalelements is or may beidentical with the spacing of the elements in the oldand previously known ladder web.

In the description in connection with Fig. 1, I have set forth the weaving of but a single set of cross-straps, Whereas ordinarily there are two sets of cross-straps, alternating along each side of the ladder web. The omission of the second set of cross-straps was in order to clearly illustrate the manner of formation of the present ladder web, and it is understood that a duplicate set of warp threads are to be provided to form the opposite half of the ladder web. In Fig. 2 I have illustrated diagrammatically the entire combination. Outer band 34 has cross-straps 21, 9 and 23, which are formed as shown in Fig. 1 and described herein. Said cross-straps have been indicated as extending from practically the edge of the outer band and extending to practically the centre of the ladderweb. A similar set of cross-straps 21', 9 and 23' are formed at the opposite edge of the ladder web by the same process as illustrated in Fig. 1.

In Fig. 3 I have illustrated a form of the invention which does not require staggered or alternate cross-straps, but all of the cross-straps may be in alignment. There is shown in dotted lines the weaving-in of one set of warp threads to form portions 2, 4 and 9, which are respectively, the weaving-in, the cross-over, and the cross-strap of one set of warp threads (see Fig. 1). There is also shown in dotted lines the elements 27, st and 33, which are respectively, the cross-strap, cross-over, and weavingin of the second set of Warp threads. There is further shown in dotted lines the elements l1, l9 and 23- which are, respectively, the weaving-in, the cross-over, and the cross-strap of the third set of warp threads.

At the same time that the above-mentioned sets of warp threads are being woven in order to produce the structure shown in Fig. 1, there is provided an additional plurality of sets of warp threads which are Woven into the structure and which cross over and through the sets of warp threads of Fig. 1. This is shown in Fig. 3, wherein the warp threads 35 cross over into the lower band at 36, continue therein over the area 31, leaving the same at point 38, and forming cross-strap 35. The threads of the cross-strap pass through and interlace with the threads of the cross-over l9, and they interlace at point 49. Said warp threads then continue, entering the upper band at 4|, being interwoven therein over :the area-:42, and leaving the same :to form cross-over 35', repeating the cycle.

A second set of warp threads 43 form part .of the .lower band, leaving the same at point .44, forming a reinforced section between points 43 and 44, and constituting cross-strap 45. These threads interlace with the cross-over threads 4 at point 46 and continue, entering the upper band at point 41. They are woven into the upper band, leaving the same at point 48, forming cross-over 49, and interlacing at 50 with the threads of cross-strap.9. They enter the lower of the upper band, leaving the same at 54, while providing a reinforced section between bands 41 and 54. They then form the cross-over 55 which interlaces with the cross-strap 21 at point 56 and enter the lower band at 51. .They continue therein forming an-area thereof .to point 58, leaving the same and forming-a cross-strap 59, and interlace at 68 with the cross-over threads 3|. They then enter the upper band at BI and continue therein overthe area 53, repeating the cycle.

From this it will'be seen that the two sets of cross-straps which previously were staggered by reason of necessity, may now be placed in alignment, and the width of the ladder web may I be decreased by atleast half, by-reason of this structure alone. -It is, of course, essential in this modification of the invention that the portions where interlacings occur, namely, points 45, 56, 48, 5B, 60, and so forth, must be constituted by weftless portions of the cross-straps.

In Fig. 4 I have illustrated, diagrammatically, the structure resulting from this modification. The outer band is provided with sets of crossstraps 45, 21, 39, 9,59 and 23', which are in the positions of the equivalent elements shown in Fig. 3. These sets of cross-straps are shown in Fig.4- as being divided into two portions 62 and 53 of the outer band, with an intermediatesection 54 not containing any cross-strap threads. Usually, section 54' is of twill weave and the warp threads thereof are continuously bound into their respective outer band. The cross-straps have been shown as spaced a short distance 65 back of the edges of the outer band. This is in accordance with prior practice, but is here shown only for purposes of illustration, it notbeing necessary to have such spacing since no detrimental effects result from placing the crossstraps up to the very edges of the outer bands.

As shown in Fig. 5, two sets only of warp threads may be used for each row of cross-straps, each set first forming part of, or being bound in with oneouter band, then crossing over to the other outer band to form a cross-strap, then forming part of, or being bound in with such other band, and finally passing back to the first band as free warps. In this example, one crossstrap formed by one set of warps lies between the cross-straps formed by the first and third set of warps, and whilst the union or binding on of each set of warps with one outer band is relatively long, and approximately equal in length to the distance between successive cross-straps, the union or binding-in with the other band is comparatively short, and parts of such outer band are of single thickness. It is; therefore, preferred to use three or more sets of warp threads for the cross-straps so that all parts of the webbing bands shall be uniform.

When the cross-strap warp threads are united with the outer hands by binding-in, the bindingin may be as shown in Fig. 6 for a plain weave, and as shown in Fig. 7 for a twill weave, the cross-strap warp threads being engaged in both cases by each weft of the bands.

As shown in Fig. 8, in place of using warp threads for the cross-straps, a series of lengths of braid, narrow tape or the like may be used, each length of braid or tape being first superimposed upon and bound to an outer band, then passed over to the other outer band to form a cross-strap and then superimposed upon and bound to the other outer band, afterwards passing back to the first outer band, and again being superimposed upon and bound to such outer band, and so on continuously.

As shown in Fig. 9, a series of no less than six narrow lengths of braid or narrow tape are used in each half of the width of the webbing, and those in one half are arranged so as to cause their cross-strap portions to lie opposite the crossstrap portions of the companion lengths of braid or tape, every seventh cross-strap in each half width being a repeat of the first crossstrap. The dispositions of the cross-straps in the two half parts of the webbing may be other than opposite each other, such as one in one half slightly in advance of one in the other half, or one in one half centrally opposite the spaces between the cross-straps in the other half.

As a result of the longer cross-strap connections, much firmer and stronger unions of the cross-straps with the outer bands are obtained, and with such increase of strength, the webbing (bands and cross-straps) may be made to narrower or lighter proportions. Again, especially in the case of the warp thread interchange method of connection, the points of connection with the outer bands will be less visible, and will not interfere with, or spoil the continuity of the weave of the bands, whichmay be plain or twill.

The improved warp-thread connection will also allow of the cross-straps being connected at points nearer to, or at the edges of the outer bands, without distorting such edges. Coarser strap warp threads may also be used, and thus give further strength to the connections, or finer yarn may be used for the cross-straps, or both for the outer bands, and the cross-straps.

If desired, the cross-straps may be weftless, in which case the webbing may be formed in one loom slot. And, to further help to lower the cost and expedite production, there may be two wefts laid in each warp shed of the outer bands, and the loom take-up motion speeded up to suit. By making the webbing and cross-straps narrower, they will be further reduced in cost. Each strap is integral with the body webs for a length equal to the distance between the straps, plus the distance required for a lath overlap; consequently giving a much greater purchase of the straps and body than hitherto.

Although I have described my invention set-= ting forth several specific embodiments thereof, my invention is not limited thereto, as said examples were intended to illustrate and not to limit the invention.

Various changes and modifications thereof are possible, for instance, in the case where the warp threads cross over from one outer band to the other and pass through cross-straps, certain of the cross straps may be composed partly of warp and weft and partly of warp only, and others may be composed of warp only.

When the cross-straps are weftless, and especially when the cross-straps lie in one row and extend across the full width of the webbing, the connetions of the strap warp threads with each band may be somewhat shorter than the distance between successive cross-straps, since the free warps in crossing over from one band to the other may pass through the weftless cross-strap. The cross-straps may be in rows opposite to each other, in which case a lath may be placed between the same to be held firmly in position, or if desired, one row of cross-straps may be slightly in advance of the adjacent row to allow of a lath passing between them and being held therey.

With weftless cross-straps, the web can be made with two shuttles and the harness tie-up accommodated on a twelve jack dobby with two jacks connected to each of the six cross-strap shafts. The body or outer-band webs are controlled from tappets in either plain, twill or check, whilst the pattern chain or lags for any size will always be three times the number used to make the size by the prior art method.

From the above it will be apparent that my inventionis to be broadly construed and not to be limited except by the character of the claims appended hereto.

What I claim is:

1. In ladder web including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises three sets of warp threads, each set forming successively a section of an outer band, a binding-in thereon, a cross-strap, the opposite binding-in and a section of the opposite outer band, and additional warp threads continuously forming part of the respective outer bands.

2. In ladder web including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of sets of warp threads, eachset forming successively a section of an outer band, a binding-in thereon, a cross-strap, a section of the opposite binding-in and the opposite outer band, and a cross-over to said first outer band, the cross-over of each set interlacing with the cross-strap of the adjacent set.

3. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of sets of warp threads, each set forming successively part of an outer band, a cross-. strap and part of the opposite outer band, and a crossover, the sets of cross-straps so formed being in alignment along the length of said webbing, the length of binding-in area of each of said sets of warp threads being substantially greater than the distance between adjacent longitudinally spaced cross-straps.

4. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of sets of warp threads, each set forming successively part of an outer band, a crossstrap and part of the opposite outer band, and a cross-over, the sets of cross-straps so formed being in alignment along the length of said webbing, the length of binding-in area of each of said sets of warp threads being substantially greater than the distance between adjacent cross-straps, a portion of said area being woven with two of said sets of warp threads.

5. In ladder webbing including two-wovenouter bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of sets of warp threads, each set forming successively part of an outerband, a crossstrap and part of the opposite outer band, and a cross-over, the sets of cross-straps so formed being in alignment along the length of said webbing, the length of binding-in; area of each of said sets of warp threads being substantially greater than the distancebetween adjacent crossstraps, a portion of said area being woven with two of said sets of warp threads adjacent to each cross-over on both of the outer bands.

6. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality ofseparated strap-forming elements taken from the class consisting of sets of warp threads, lengths of braid and narrow tape, each element being successively woven into an outer band, then crossing over to the opposite outer-band to form a cross-strap, then being woven into said opposite outer band, and finally passing back to the first band to start a fresh cycle, each of said elements forming a set of cross-straps, the crossstrap of each set alternating with the corresponding cross-strap of the other sets, said cross-straps being equally spaced and inlongitudinal alignment on said webbing; the longitudinally adjacent cross-straps being formed from different strap-forming elements.

7. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of separated strap-forming elements taken from the class consisting of sets of warp threads, lengths of braid and narrow tape, each element being successively woven into an outer band, then crossing over to the opposite outer band to form a cross-strap, then being woven into said opposite outer band, and finally passing back to the first band to start a fresh cycle, each of said elements forming a set of cross-straps, the cross-straps of each set alternating with the corresponding cross-straps of the other sets, said cross-straps being equally spaced and in longitudinal alignment on said webbing, the longitudinally adjacent cross-straps being formed from different strap-forming elements, each of said cross-strap elements being woven into the outer bands for a distance at least equal to the distance between said successive cross-straps.

8. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises three separate sets of separated strap-forming elements taken from the class consisting of sets of warp threads, lengths of braid and narrow tape, each element being successively woven into an outer band, then crossing over to the opposite outer band to form a cross-strap, then being Woven into said opposite outer band, and finally passing back to the first band to start a fresh cycle, each of said elements forming a set of cross-straps, the cross strap of each of the three sets alternating with the corresponding cross-strap of the other sets, said. cross-straps being equally spaced and in longitudinal alignment on said webbing, the longitudinally adjacent cross-straps being formed from different strap-forming elements.

9. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises two separate sets of separated strap-forming elements cross-straps of each of the two sets alternating with the corresponding cross-straps of the other sets, said cross-straps being equally spaced and in longitudinal alignment on said webbing, the longitudinally adjacent cross-straps being formed from. different strap-forming elements.

1-0. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of separated strap-forming elements taken from the class consisting of sets of wrap threads, lengths of braid: and narrow tape, each element being successively woven into, an outer band, then crossing over to the opposite outer band to form a cross-strap, then being woven into said opposite outer band, and finally passing back to the first band to start a fresh cycle, each of said elements formi a set of cross-straps, the cross-straps of each set alternating with the corresponding cross-straps of the other sets, said cross-straps being equally spaced and in longitudinal alignment on said webbing, the longitudinally adjacent cross-straps being formed from different strap-forming elements, those portions of each of said strap-forming elements woven into one outer band being shorter than those portions thereof which are woven into the opposite outer band.

11. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of separated sets of warp threads, each set forming successively part of the warp of a woven outer band, a cross-strap and part of the warp of the opposite outer band and a cross-over, the sets of cross-straps being in longitudinal aligmnent along said webbing, said cross-straps being weftless, the successive longitudinally aligned cross-straps being formed from different sets of cross-strap warp threads,

12, In ladder webbing including two woven. outer bands and cross-straps therebetween at spaced intervals, the improvement which c0mprises three separated sets of warp threads, each set forming successively part of the warp of a woven outer band, a cross-strap and part of the warp of the opposite outer band and a cross" over, the sets of cross-straps being in longitudinal alignment along said webbing, said crossstraps being weftless, the successive longitudinally aligned cross-straps being formed from different sets of cross-strap warp threads.

13. In ladder webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of separated sets of warp threads, each set forming successively part of the warp of a woven outer band, a cross-strap and part of the warp of the opposite outer band and a cross-over, the sets of cross-straps being in longitudinal alignment along said webbing, said cross-straps being weftless, the successive longitudinally aligned cross-straps being formed from different sets of cross-strap warp threads, said cross-straps extending substantially to the lateral edges of said outer bands.

14. In ladder Webbing including two woven outer bands and cross-straps therebetween at spaced intervals, the improvement which comprises a plurality of separated strap-forming elements taken from the class consisting of sets of warp threads, lengths of braid and narrow tape, each element being successively woven into an outer band, then crossing over to the opposite outer band to form a cross-strap, then being woven into said opposite outer band, and finally passing back to the first band to start a fresh cycle, each of said elements forming a set of cross-straps, the cross-strap of each set alternating with the corresponding cross-strap of the other sets, said cross-straps being equally spaced and in longitudinal alignment on said Webbing, the longitudinally adjacent cross-straps being formed from different strap-forming elements, the components of said strap-forming elements being spaced apart transversely of the webbing, thereby providing a plurality of transversely aligned cross-straps from each of said elements.

15. A ladder tape including: first and second main tapes each formed of warp strands woven with weft strands, part of which warp strands of each tape consist of, at least three warpwisealigned sets of ladder-warp strands which sets also form ladders connecting said main tapes and each of which sets is successively woven with weft strands of said first main tape, then forms a ladder as it extends over to said second main tape where it is woven with weft strands of said second main tape, then forms a crossover to said first main tape where it is woven with weft strands of said first main tape, and

so on, each woven-invsection of each of said sets of ladder warp strands being of substantially greater length than the distance between two adjacent warpwise-aligned ladders and having portions in overlapping woven relation with the immediately preceding and following woven-in sections of sets of ladder warp strands of a main tape.

16. A ladder tape including: first and second main tapes each formed of groups of warp strands woven with weft strands, part of which warp strands of each tape consist of at least three warpwise-aligned sets of ladder-warp strands which sets also form ladders connecting said main tapes and each of which sets is successively woven with weft strands of said first main tape, then forms a ladder as it extends over to said second main tape where it is woven with weft strands of said second main tape, then forms a cross-over to said first main tape where it is woven with weft strands of said first main tape, and so on, each woven-in section of each of said sets of ladder warp strands being of substantially greater length than the distance between two adjacent warpwise-aligned ladders and having portions in overlapping woven relation with the immediately preceding and following woven-in sections of sets of warp strands of a main tape, and substantially each wovenin section of substantially each ladder warp strand of said sets of ladder warp strands forming a section of a said group of warp strands.

GEORGE FREDERICK FRENCH.

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