US2775265A - Venetian blind ladder and like webbing - Google Patents

Description

Dec. 25, 1956 G. F. FRENCH ETAL 2,775,255

VENETIAN BLIND LADDER AND LIKE WEBBI Filed Nov. 6, 1951 United States Patent '0 VENETIAN BLIND LADDER vAN D LIKE; WEBBING George Frederick French and Roger. French, Hale, England; Roger French, AlfredHanson, and Neville Christopher OBriemexecutors ofthe estate of GeorgeFred erick Frenchydeceased, assignors to said Roger French Application November 6, 1951,. Serial N. 255,088...

Claims P y, pplication Great Britain November 7, 1950- 10.01am. (Cl. .139384) This M invention. relates .to: Venetian. blind ladder and like. webbing of. theflkind comprising two :orzmore outer or main. bandings. between which are woven or;.partly wovemcross straps arrangediin .one or more rows and in whichvthe cross straps .in anyone. row, or in laterally overlapping rows, are .of such length as to overlap longis tudinally i. e. in their length sohthatone. set oftwarps initially cross.overnthroughanother. Suchoverlap may.

provide; the ,required overlap for the; blind: laths. 1

While such webbing is primarily known. and. used for Venetian blinds,- it has. other.uses', for. example, as a liningfonheadgear to hold. cork or like inserts between. the. .cross. straps, furniture, beds, upholstery, but for convenience such: webbing .will. be referred to hereinafter by the generic term. ladder webbing.

Examples .of ladder. webbing of .the kind above referred to are described. .in our prior British. patent specification.

No. 512,835. particularly with reference. to. Figs. 11,12. and 13. Whilstsuchwebbing may easily be madevwith. the cross.strapsunwoven, certain problems arise; when such .cross straps..are. to be woven or partly woven-due to the. combinedlongitudinal and lateral overlaps. For

example, inwa simple arrangement in whichthere are two sets of warp threads for the cross straps (one SetvfOIT:

each alternate. cross strap) due. to. such combined overlap ,the warps of one .sethaveto pass throughlithetwarps ofthe. other alternately in the. length of each cross strap.

In consequence, .such .kind of ladder webbing has :so far. only been .made. with .unwoven or weftless cross strapsandthe present invention has for its. objectto providewan. improved ladder. webbing and method of making qthe.

samewith woven .or :partly. woven cross straps.

The main object of i the. invention is to pprovide ladder Webbing of the type described hereinbeforehaving. an.

improved character which enables..productio.n costs to befreduced. by simplification. .of the weaving. process and increased loomspeed.

A- further object of thetinvention is .to providerladder webbing of .thetype describedhereinbefore which. whilst lighter and narrower than known types ofJadderWeb-p bing, maintains a. given tensile strength.

A still further object of the inventionis to provide such ladder. webbing .in .Which. the. whole-or only certainw parts of the. cross straps .are woven and in which UIl'w woven warpsware-xdefined by adjacent. woven port-ions.

By buttonholes aremeant apertures throughwhich liftingcords or the like may be passed.

These and many other objectsand advantages will be apparent from the following descriptio-nwand claimss The invention will be described further by Way of example with reference. to the accompanying drawings in which:

Fig; 1 is a perspective view of one exampleofladder webbing. made inaccordance with the present invention and having two main bands and a single row of cross straps 'in line;

2.. Fig. 2 is a fragment-aryview. of a modification of the cross straps shown in Fig.1;

Fig. 3 isa fragmentary .view of a. further modification of oneof the cross straps shown in Fig. l;

Fig. 4 is a perspective view showing a modification of Fig. 1;

Fig. 5 is a fragmentary view of a further modification of a cross strap made in accordance with the invention; Fig. 6 is a perspective view of astill further modified construction.

In one example of the invention as illustrated in Fig.

l ladder webbing having a singlelongitudinal row of cross. straps 11 between main bandings 25, 26, formed. from two sets of warp threads and overlapping in, their length, the webbing is woven -with..four shuttles asfor theprevious ladder web, in which the two middle shuttles Weavethe warps of the staggered .two rows of .cross. straps, but with this difference that, when the crossing over of the strap warpsis effected the shuttle which has previouslybeen weaving aportion. of one cross :strap, is. nowused to weave a similar portion of the consecutive.

cross strap. Thus, from the point of such. cross. over,

each strap at one end is wovenwith weft 12 by one shut tie .and at the other end is woven. with weft 13 by the other of the two shuttles-allocated for weavingthe cross straps.

in eachstrap 11 which will take any wear due to. the passage of the lifting cords as the blind. is .raised and lowered. Also, as has been previously suggested, only some ofthe strap warp threadsmay be Woven the remainder 17 being weftless so that theablind laths maybe held between the woven and unwoven warp threads and the lath held in position (Fig. 4).

In a further. modification shown in Fig. 5, the shedding;

is effected to produce a button-hole 1i8.ir1.each cross strap 11. This is possible because, during the binding-in of the ends of one set of warps forthe. cross straps 11, both strap shuttles are rnade available for weaving thecentrebuttonhole portion 18 of the said cross strap 11. Thus, in any one cross strap the vweft 12 from one shuttle will be continuous from .one. end and extend along one side-- of the buttonrhole18, while the other side of .the-button-- hole 18 and the other endof the strap 11 will be woven..- by Weft 13'frorn the othershuttler The button-hole 18 can therefore bemade without increasing theinumber of shuttles, i. e. still using only 4 shuttles and can extend;

for the combined ,length of the top and bottom binding in.

It will of course be appreciated that, in the buttonhole construction, while .both the intermediate shuttles are being used for weaving thetwo halves of the cross strap it will not be possible to use eitherof these shuttles for the purpose ofstrengthening thebinding-in as is done in accordance with our earlier British PatentNo. 453,832.

In all other examples it isequally to be appreciated that the use of the cross strap shuttles for strengthening the binding-in can be adopted.

The improved construction makes it possible to produce a narrower and lighterladder webbing yet having a broader and stronger. lath. strap by employing more strap warp threads. Such improved webbing will be quicker and easier to manufactureandalso cheaper. The actualsheddingcanbe simplified to eliminatesomeofthe major.

Patented .Dec. 25, 1956 changes thus reducing the shock and requiring less skill and maintenance and enabling the loom speed to be increased. For a cross strap of previously determined tensile strength it is possible to have wider cross strap with fewer picks which will consequently give quicker production and cheaper cost and at the same time retain its tensile strength. The partly woven, partly weftless form has advantages over the weftless form described in our previous patents in that the partly woven strap is enough to prevent the weftless strap warp thread portion from spreading so as to be visible at the sides of the main bands. Thus, for example with the improved construction of ladder web narrower outer bandings can be used whilst the present strap web width could be retained, or increased if necessary, thereby giving equal or greater purchasing power of the straps to the body Webs than in the previously known constructions. Further, the laths are held centrally of the outer bandings.

With body webs 1" wide as against the present 1 /2 the cost of raw materials would be reduced by approximately one-third. Again, loom efliciency would be increased by the fact that approximately one-third more running time would be provided for each weft package on the bandings or body webs. The method of lifting the strap warps may be such that heavy lifts (i. e. over three or four shuttles) could be eliminated thereby allowing the loom to be run at a higher speed.

Instead of keeping the cross straps'of the same width as at present which is substantially a practical maximum width, the said strap width may be increased and strengthened by the introduction of extra threads giving a resultant firmer binding-in and whilst an increase may apparently have a disadvantage it does in fact leave a substantial advantage in that the picks per inch could be reduced, enabling the rate of production to be increased whilst such cross straps would still retain their former strength of binding-in to the outer bandings. Another constructional advantage where the cross straps are in a longitudinal line is not only that the warp tensions in the fabric are balanced, but also the same amount of weft is drawn from the shuttles at each pick, whereas with the staggered cross strap method this was not possible, the weft being pulled off the shuttles unequally at each side.

In a further extension of the principle of the invention cross straps 11 (see Fig. 6) need not be wholly in line but may overlap laterally to a greater or lesser degree.

What we claim is:

1. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, successive cross straps each having portions at least thereof relative to and between its bound-in ends woven, one portion with picks of one common weft thread and another portion with picks of a difierent common weft thread.

2. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being formed alternately from two sets of warp threads and being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, successive cross straps each having portions at least thereof relative to and between its bound-in ends woven, one portion with picks of one common weft thread and another portion with picks of a different common weft thread.

3. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set'of warp threads initially cross over through another set, each successive cross strap being at least partially woven with picks of at least two different common wef threads.

4. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, successive cross straps each having like portions at least thereof relative to and between its bound-in ends woven, one portion with picks of one common weft thread and another portion with picks of a different common weft thread.

5. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, successive cross straps each having at least two diflferent portions woven between its bound-in ends, one portion of each cross strap being like one portion of each other cross strap and all such like portions being woven with picks of one common weft thread, another portion of each cross strap being like another portion of each other cross strap and all such other like portions being woven with picks of a difierent common weft thread.

6. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, the same part, relative to and between its bound-in ends, of each successive cross strap being woven with picks of one common Weft thread and another corresponding part be tween the bound-in ends of each successive cross strap being woven with picks of a diiferent common weft thread, said two parts defining on each cross strap a portion of unwoven warp threads through which lifting cords may be passed. p

7. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, corresponding halves, relative totheir bound-in ends, of each cross strap being woven with picks of one common weft thread and the other halves with picks of a second and difierent common weft thread.

8. A ladder webbing comprising at least two outer main bandings and at least one row of cross straps bound in at their ends between any adjacent two main bandings, successive cross straps being of such length that in-line portions thereof overlap longitudinally, so that one set of warp threads initially cross over through another set, the same part, relative to and between its bound in ends and being less than half thereof, of each successive cross strap being woven with picks of one common weft thread, and another corresponding part of each successive cross strap between its bound-in ends and being also less than half thereof, being woven with picks of a second and different common weft thread, said two parts defining on each cross strap a portion of 'unwoven warp threads successive cross straps in each row being staggeredtransversely but having in-line portions thereof overlapping longitudinally, so that one set of Warp threads cross over and at least partially through another set, successive cross straps each having portions at least thereof relative to and between its bound-in ends woven, one portion with picks of one common weft thread and another portion with picks of a difierent common weft thread.

References Cited in the file of this patent UNITED STATES PATENTS Re. 22,925 Rasero Oct. 7, 1947 6 French Apr. 25, 1939 French Apr. 25, 1939 French Apr. 15, 1941 FOREIGN PATENTS Great Britain Oct. 4, 1940

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