US2537865A - Venetian blind ladder - Google Patents

Description

Jan. 9, 1951 w. J. STUBER ET AL 2,537,865

VENETIAN BLIND LADDER Filed Feb. 1, 1947 f3 10 INVENTORS L WALTER MSn/BMAND 34 BY ARNOLD I'VE/$554 BERG A T TOR/V5 Y Patented Jan. 9, 1951 UNITED STATES PTENT OFFICE 'Weisselberg, Leonia, N. .'I., assignors to Carey- McFail Company, Philadelphia, Pa., a corporation of Pennsylvania Application February 1, 1947, SerialNo. 725,956

'2 Claims.

Theinvention relates to a novel Venetian blind ladder constructed of tape in the nature of a fabric of relatively open mesh.

In the construction of these ladders, it has been thepractice heretofore to unite parallel and vertically extending tape elements to cross bars generally of the same material, as b sewing, interweaving or cementing the same in place .at regularzintervals along the tape elements.

It is an object of the present invention to providea ladder of this general nature but wherein .a simple and highly effective union of cross bars to tapesis attained.

A further object of the invention is to provide the'tapes as well as the cross bars of which a lad- .derJis constructed of an open-mesh fabric surfaced with a moisture-proof layer of flexible and "fusible plastic material covering one surface only of the material.

.Another object of the invention is to provide a ladder construction wherein the plastic material extends entirely through the interstices of the fabric only at the portions at which bonding is effected with the cross bars.

'-It is an additional object of the invention to provide a joint between the vertical tapes and the cross bars through a multiplicity of bonds of plas- "tic material extrusions, whereby fabric of the tapes and cross bars or solely of the tapes becomes locked between two strips of the said plastic material and isnot afiorded merely by an uncertain surface adhesion of cemented plastic and fabric "as heretofore.

' The invention has for an object, also, to provide cross bars which will afford ample clearance longitudinally of the bars to avoid any tendency of the "slat operating cord of the blind to bind in or become jammed with respect to the bars.

'Still another object of the invention is to provide a ladder wherein the cross bars all are of a width less than one-half the width of the tapes and'are connected thereto alon corresponding edges of said tapes at the outer side thereof only to allow ready removal and replacement of the tapes from the slats of the blind.

In carrying out the invention, the tapes are selected of fabric of a suitably open mesh to perm-it'of the extrusion therethrough of fusible plastic material from the one surface of a tape. It is to be understood, in the use of the term open 'mesh or expressions of similar import herein and in the claims, that the mesh of the tapewith re- "lation to the diameters of its fibers meets this re- '-*q'uirement. By juxtaposing the ends of cross bars, which maybe of like fabric-plastic-surfaced ma- 'terial or simply be of fusible plastic 'materiaL'to corresponding tapes and then subjecting the'juX- taposed portions to the application of heatiarrd pressure, the surfacing plastic material is extruded through the fabric interstices to wel'd'the plastic elements together through a multiplicity of integral bonds formed in situ to lock 'inbetween said elements the intermediate fabric material. This precludes possible stripping at 'a joint of the plastic material from the fabric, as occurs when it is attempted to secure the junction of plastic to plastic and fabric to plastic in the cementing of the one to the other. It avoids, also, discontinuity of attachment in'such joint, such as would result from vaporization of the cementing substance and prevention of .escapeof the vapors by an impervious plastic coating.

By thus securing a markedly more perfect joint at the cross bar ends, it becomes possible-with plastic-surfaced fabric to reduce substantially'the width of said cross bars to an extent that they may be constructed less than one-half the width of the tapes to which they are to besecured. All the cross bars of one pair of tapes may, therefore, be arranged along the respective edges thereof at one side (the outer one) of the pairs of 'tap'esand thus provide for the convenient and rapidseparation of an end ladder from the blind slats, supported on the cross bars, merely by disconnecting the tapes thereof from their top and bottom connections to the blind.

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary underneath plan and Fig. 2 a longitudinal section, both on an enlarged scale, of a piece of plastic-surfaced fabric'as utilized in the'novel ladder.

Fig. 3 is a fragmentary horizontal section'o'f a juxtaposed cross bar end and tape preparatory to effecting a joint therebetween; and Fig. 4 is a similar view showing the same bonded in the novel manner, both views being on a greatly enlarged scale.

Figs. 5 and 6 are views similar to Figs. -3 and 4 "and illustrate a modification.

Fig. '7 is a fragmentary perspective view of a portion of a Venetian blind ladder assembly embodying the novel bond of crossbar with tapes;

and illustrates also a novel type of cross bar.

Fig. 8 is a horizontal section, with slat omitted,

through a ladder assembly embodying the'novel bond, and illustrates a "modification in the cross bar arrangement.

Fig. 9 is a'fragmentary sideelevation-deflatider constructed in the novel manner and illustrates a further modification.

Fig. is a vertical section taken on the line Ill-40, Fig. 9, and looking in the direction of the arrows; and Fig. 11 is a fragmentary plan thereof.

Fig. 12 is a fragmentary plan view illustrating a further modification in the cross bar connection to tapes.

Referring to the drawings, the novel ladder is shown as constructed throughout of the same material, namely: plastic-surfaced, open-mesh fabric H] such as is illustrated in Figs. 1 and 2, the surfacing being on one side thereof only. This fabric should be composed of inelastic or substantially non-stretchable fibers of adequate strength and of a weave affording openings of sufficient area to permit of ready extrusion therethrough of the plastic-surface material I I under the application of heat and pressure thereto. It has been found that a satisfactory ratio of fiber diameter to mesh ranging from to will provide a suitable open mesh, which term, as has already been indicated, is intended to include material meeting the aforesaid requirement. Marquisette cloth has been found particularly suitable for the purpose, such as with the warp and woof threads each being approximately 0.006" in diameter and the weave such as to afford openings of 0.024 or approximately 34-43 threads per inch of material.

This material is overlaid or surfaced on one face only with a relatively thin strip of suitable plastic material, the thickness of the latter not exceeding generally 0.015 and, preferably, being about 0.010 so as not to impair appreciably the flexibility of the cloth to which it has been applied. Vinyl chloride, because of its property of not becoming brittle over a wide range of temperatures and of not aging appreciably over long periods of time, affords a very satisfactory coating, although it is to be understood that various other plastic synthetic resins of sufficient flexibility and waterproof characteristics may be utilized provided they may be extruded through the fabric under pressure and temperature application compatible with the cloth material and general processing operations. These are of the nature generally employed in plastic extrusion operations, such as those involving the utilization of high frequency heating and simultaneous application of pressure. While in the instant example the plastic material for both tapes and cross bars is the same, it will be understood that these may be difierent so long as they are compatible with each other with respect to fusion and extrusion properties.

It is to be noted that in the preparation of the surfaced elements for use in constructing a ladder therefrom, the plastic material [I should not have the fibers of the cloth extend therein for a distance more than approximately that equal to the radius of a fiber, whereby the surface 12 of the cloth or fabric opposite the surfacing material remains substantially free of the plastic. In utilizing cloth of fiber dimensions of the example hereinbefore set forth, the total thickness of such fabric with plastic will then be approximately 0.019".

The thus-surfaced material is utilized for the tapes l3 and i i of the ladder as well as for the cross bars [5 thereof, Fig. 7; and the novel bonds provided between the respective ends of the bars I5 and the corresponding vertically extending tapes l3 and M are best effected by juxtaposing non-surfaced faces of ends l3 and W of said cross bars and of the corresponding tapes, Fig. 3, the cross bars being interconnected with said tapes at regular intervals as is the usual practice. A bond is effected preferably by the application of known extrusion methods, as hereinbefore noted, to the juxtaposed portions. Such application will provide for a multiplicity of extrusions 18, Fig. i, affording bonds between opposite plastic surfaces and extending through the interstices of the fabric 40, which extrusions integrally bond the two plastic surfacing portions to each other and at the same time the fibers of the cloth reinforce the joint against tensile stresses, particularly those applied longitudinally of the tapes and joint portions thereof. A reduction at the joint in thickness of the juxtaposed members results, the finished joints, Fig. 4, being approximately 0.029 thick in the specific example as a result of the bonding, whereas the over-all unbonded thickness of the superposed surfaced fabric layers originally amounted to approximately 0.038.

Or, as indicated in Figs. 5 and 6, one of the juxtaposed portions 20 and 2 I, such as the cross bars 21 which are not subject to any appreciable longitudinal stress in use, may consist solely of plastic.

In Fig. 12, a further modification is indicated, the cross bars 22 being shown as butt-welded at their respective ends to the tapes 23, as shown at 24.

In the ladder assembly shown in Fig. 7, a novel form of the cross bars 15 is indicated, the same being shown as of substantially the full width of the tapes i3 and M, but having a longitudinal slot 25 provided therein whereby to accommodate the control cord 25 which will thus remain much more free under the various angular positions assumed by the cross bars in adjusting the slats of a blind of this nature.

Fig. 8 shows a somewhat similar arrangement, the cross bars being constructed of a pair of separated strips 27, 28 disposed along both sides of the tapes 29 and 30 and said strips each being of a width somewhat less than one-half the width of the tapes to which they are bonded. This provides a longitudinal opening 3! substantially midway of a bar to accommodate the control cord 32.

A still further modification is shown in Figs. 9 to 11. In this embodiment, the cross bars 35 are indicated as all disposed along only one of the corresponding sides (the outer ones) of a pair of vertically extending tapes 3% and 37, and are of a width somewhat less than one-half the width of a tape so as to lie at one side of its median line to allow a free play of the control cord 38. The construction admits, furthermore, of readily withdrawing a ladder from its supported slats 39 merely by detaching the ladder ends at the tops and bottoms from the usual ladder rails (not shown) and then pulling the said ladder laterally beyond the corresponding ends of the slats. Also, the respective end portions 40 and M of the cross bars 35, where joined to the corresponding tapes, may be directed oppositely to each other. Thus, the portion 40 extends upwardly and the portion ti downwardly of the cross bars.

We claim:

1. In a Venetian blind ladder-assembly including a pair of parallel, vertically extending, openmesh fabric tapes and cross bars having their opposite ends juxtaposed to the respective tapes at regular intervals: means securing said ends to the respective tapes comprising a coating of plastic material over the outer surface only of each of the tapes, said coating having a multiplicity of penetrations of the plastic coating through the interstices of the fabric, the same extending to the inner surface thereof and only at the respective juxtaposed cross bar ends which are turned thereat parallel to the tapes and contact said ends and bonded thereto to form an integral joint between the respective tapes and the said juxtaposed cross bar ends, as well as to anchor the tape coatings at corresponding intervals along the tapes.

2. A Venetian blind ladder-assembly according to claim 1, wherein the cross bars are of fabric and are coated with a plastic material only over their respective surfaces not contacting with the tapes and said material is integrally bonded to the ends of the penetrations.

WALTER J. STUBER. ARNOLD WEISSELBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Images