US2669301A - Venetian blind - Google Patents

Description

Feb. 16, 1954' C. S. EVANS VENETIAN BLIND Filed Oct. 14, 1946 INVENTOR body which flattens into a strong,

tion, showing on an enlarged scale that portion of Figure 1 which is enclosed by the dotted circle 5.

Figure 6 is a vertical sectional view through the bottom rail and lower slat. The plane of section is indicated by the line 6-6 of Figure 1. Figure '7 is a plan view, and Figure 8 is an elevation partly in vertical section of a fastening element slidably supported on the twin cross tapes. Figure 8 is on an enlarged scale; and in all of the figures small or thin parts are necessarily shown somewhat out of scale.

A Venetian blind generally includes a series of thin horizontal slats, with mechanism for adjusting their vertical position to vary the amount of window opening covered; and mechanism for tilting the slats with reference to the horizontal plane in order to vary the degree of opening of the blind; at all times the slats being maintained in parallelism. My invention is not primarily concerned with either the lifting cord lock or the tilting mechanism; excellent devices for those purposes having long been available. These por tions of the blind embodied in my invention will therefore be referred to, but not explained in detail.

My blind comprises a ceiling board 2 having a tilting head 3 of common worm gear type at one end, and a bracket 4 at the other end forming part of the cord lock 5. between the tilting head 3 and the bracket; and cords 8 hanging down on the left side of the blind, provide means for turning the tilt rail. A molding 9 secured to the ceiling board extends across the front of the structure and conceals the tilt rail,

' tilting head and cord lock.

Detachably secured to the tilt rail near each end is a ladder tape in which the slats it are hung and demountably secured. Each ladder tape comprises front and rear vertical webs l2 and I3 respectively, extending downwardly from the tilt rail to the bottom rail it. A detachable fastening means i'l, preferably of snap fastener type, secures the end of each web to the bottom rail.

By snap fastener, I mean two-part releasable connecting device, comprising an annularly grooved stud which is fixed on one of the parts to be connected, and a resilient ring into which the stud may be inserted to be resiliently held thereby, and which is fixed on the other part.

The upper ends of the ladder tape webs are releasably connected by snap fasteners 18 to op posite ends of the saddle 19, fixed by double pointed tacks 2! to the top surface of the tilting rail; and hanging free over the curved sides of the rail as shown in Figure 1. The saddle may be made of thin leather or of light canvas stitched about the edges to prevent raveling. When laid out flat the saddle has the shape of an elongated ring. The center opening provides a free space surrounding the groove 22 in the side of the tilt rail, through which the lifting cord 23 passes.

The proportion and arrangement of parts are such that when the tilt rail is horizontal the bottom rail is also horizontal. Extending between the vertical webs l2 and 13 of each ladder tape are the rung tapes or cross tapes on which the slats 9 lie; and these are evenly spaced lengthwise of the webs so that the slats lying thereon will maintain parallelism with each other and with the tilt and bottom rails.

The rung tapes are arranged in pairs 25 and 2t; and preferably are formed of a braided tubular double-thick- A tilt rail 1 is supported 4 ness, rather narrow cord-like tape. The ends are woven or sewed to the web; and at midpoint between the webs, the ring member 21 of a snap fastener is secured to both; the two parts of the ring clamping the tapes securely between them. Preferably the points of securement of the twin tapes to the webs and the fastener ring are such as to space their outer ends somewhat further apart than their midpoints caught in the fastener ring, as shown in Figure 2. There are several reasons for this: a more even and balanced stress is placed on the webs; there is less tendency for the fastener ring to tip out of the horizontal, easily engageable position when free of the slat; there is less tendency of the slats to sway lengthwise so that the blind has a greater vertical stability; and a freeway for the lifting cord with no frictional engagement against the tapes is ensured.

Lying on the corresponding sets of twin tapes in each ladder are the slats it, each of which carries a stud member 28, so placed that when snapped into its associate ring 21, the slat is aligned laterally with other slats and with the bottom rail. It is to be noted that the slat is demountably secured directly to the twin supporting tapes, and through them to the vertical webs of the ladder. The eye demands alignment of the slats with the ladder webs which are the dominant vertical element in the design formed by the blind as a whole. The twin cross tapes are held taut by the weight of the slat; and since the slat is fastened to the twin tapes, accurate alignment is assured.

While a snap ring may join the centers of each set of twin tapes, as shown in Figure 2, and associate studs placed on each slat, it is preferred for reasons involving costs of manufacture and ease with which the slats may be detached and taken out, to use but one snap fastener to a slat; and to stagger these in the two ladders, so that as to each ladder, alternate slats are fastened to the twin tapes, the other end of the fastened slat being unsecured to the twin tapes on which it lies.

It will be noted that bringing the center portions of the twin tapes closer together in the snap ring, than the ends fixed to the vertical webs, tends to shorten the distance between the latter, so that when fasteners are applied to every other set of twin tapes, the intervening sets are, in effect, somewhat longer since they extend straight across between the webs. This small variation when it occurs may be readily eliminated if desired during manufacture of the ladder tape, but the variation is so slight as to be negligible. Furthermore any variation is symmetrical and balanced from the side to side and for that reason is unnoticeable.

Means are provided for lifting the bottom rail so that as it rises, the slats are successively stacked thereon, until all are collected at the top of the blind between it and the tilt rail. On its upper face the ceiling board is formed with grooves in which lie the two strands of a cord loop 32. One strand 23 passes over a pulley 34 and down through the underlying saddle l9 and groove 22 in the side of the tilt rail, then down between the rear edge of the slats and the rear web l3, and through the spaces between the ends of the twin tapes supporting each slat, to the bottom rail where the end passes through a groove 36 and terminates in a knot seated in a recess 31 formed to one side of the center in the bottom of the rail where it is covered by the bottom end of the web.

The other strand 38 passes over pulley 39, and extends down similarly but in front of the slats and next to the front web I2. The two lifting cords 23 and 38, secured on opposite sides of the bottom rail are sufiioient, but with a particularly long or heavy blind, a lifting cord may be arranged on each side next the front and rear webs in each ladder tape.

As the blind is pulled up from its lower position to stack the slats on the lower rail, the lifting cord moves smoothly upwardly with no lateral contact with the twin cross tapes since it lies midway between them; and with but light engagement with slat and web. With long and heavy blinds, it may be desirable to relieve the slat a small amount along the edge adjacent the lifting cord, as shown at 42, Figure 3, so that the cord moves past the slat with substantially no rubbing of the edge. Because each lifting cord, from bottom rail to top pulley, is almost free of frictional drag, except for a slight amount from the web which decreases as the blind is raised, my blind is noticeably easy to operate. Because of the balanced distribution of stresses on the webs, which results from the twin rung tapes, there is no tendency to uneven folding of the webs, which gather into vertically aligned and even folds as the blind rises. This result is materially aided by the securement of the slats to the rung tapes since that construction tends to prevent relative lateral movement of either one while promoting vertical alignment of the slats as the stack forms.

From the foregoing explanation it will be clear that the slats are readily demountable; and that any one or all of them may be detached from the rung tapes by separation of the fastener elements, and then removed from the blind for cleansing or other treatment, after which they may be reinserted and snapped in place. If it is desired to clean or replace the ladder tapes, the slats are first unsnapped and removed. The lower snaps I! are then opened to free the lower rail from the ends at the bottom of each ladder web, and disengage the knotted ends of the lifting cords from the recesses in the bottom face of the rail. The rail may then be removed. By disengaging the snaps l8 on both sides of the saddle, the ladder tape may be pulled free, leaving the lifting cords hanging loose from the tilt rail, ready for reassembly of ladder tape, bottom rail and slats.

In Figures 7 and 8, I have shown a modificae tion of the rung tape and fastener structure. It is desirable in some cases to space the twin rung tapes further apart than can be caught by a rather small standard fastener element. Sometimes also it is an advantage to permit a small amount of shifting of the slat along the rung tapes toward one of the webs. Either or both of these conditions may be satisfied by setting the two elements 48 and -41 of the fastener ring on opposite sides of a thin plate 48 having an aperture 49 therethrough in which the fastener is centered. The fastener thus is mounted directly on the plate instead of directly on the twin tapes as in Figure 2. It will be obvious that instead of inserting a, thin apertured plate between the fastener elements, the lower element itself may be extended on opposite sides to provide the desired plate. In either case, the opposite ends of the plate are bent over and under as shown, to provide broad open resilient eyes 5| adapted to be hooked over the twin rung tapes 52, as shown in Figure 8.

The opening of the eye should be sufficient to permit entrance of the tape under light stress and free movement of the plate along the tape, if such movement is desired. If the plate is to be fixed on the cross tapes, the eye is smaller so as to clamp the tape therein.

I claim:

1. A ladder tape for a Venetian blind comprising spaced webs, twin rung tapes spaced apart and connected at their ends to the webs, and a fastener element bridged across the twin tapes intermediate their ends, the distance between the twin tapes at the fastener element being less than between their ends.

2. A ladder tape for a Venetian blind comprising spaced webs, twin rung tapes spaced apart and connected at their ends to the webs, a plate bridged across the twin tapes intermediate their ends and spacing the tapes closer together than at their ends, and means adjacent opposite edges of the plate to fix the plate to the rung tapes.

3. A ladder tape for a Venetian blind comprising spaced webs, twin rung tapes spaced apart and connected at their ends to the webs, a plate bridged across the twin tapes intermediate their ends and spacing the tapes closer together than at their ends, and opposing surfaces adjacent opposite edges of the plate to fix the plate to the rung tapes.

CHARLES S. EVANS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 451,924 Fisher May 12, 1891 1,861,606 Mackin June 7, 1932 2,031,981 Runge Feb. 25, 1936 2,043,501 Wood June 9, 1936 2,111,978 Lawson et a1 Mar. 22, 1938 2,123,817 Warren July 12, 1938 2,141,502 Ajouelo Dec. 27, 1938 2,200,349 Walker May 14, 1940 2,311,716 Walker Feb. 23, 1943 2,317,660 Williams Apr. 27, 1943 2,381,060 Kahn Aug. 7, 1945

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