Patent Description:
<CIT> discloses a window blind that has a plurality of connectors. Each of the connectors passes through the holes formed on the slats from above. Each of the connectors has a first end connected to the rear vertical portion of the ladder, and each of the connectors has a second end formed with a loop portion for a lifting cord to pass therethrough, so that the lifting cord can only be moved vertically but not transversely. In addition, after passing through the holes of the slats, the second end of the connector can be provided with a stopper formed by a metal sheet or a knot to prevent the connector from slipping off the slats.

In the prior patent, however, although the connector is flexible, the small hole diameter makes it time-consuming to pass the connector through the hole from above. Further, after the time-consuming threading operation, there is an additional step to use the metal sheet to hold the second end of the connector or to knot the second end of the connector, making the overall assembling work more difficult. Once any of the assembled slats gets damaged and needs to be replaced, it is necessary to detach the metal sheet or unknot the second end before taking further maintenance or repair actions.

<CIT> discloses a window blind having upper and lower beams linked by two ladder-like ropes, that has a front vertical portion, a rear vertical portion, transverse portions connected between the vertical portions, first ring portions connected to the front vertical portion, second ring portions connected to the rear vertical portion, and third ring portions connected to the front vertical portion. The transverse portion supports a slat from below. The slat has two ends thereof each provided with a through hole and a slot communicated with the through hole. To assemble the slat, the third ring portion of the ladder-like rope has one segment inlaid into the through hole of the slat through the slot, and then the third ring portion is mounted around the front edge of the slat.

However, the above cited prior art is inconvenient in terms of assembling, and improvement is therefore desirable.

It is a primary objective of the present invention to provide a venetian blind that is structurally simple and easy to be assembled, in which its slats are prevented from excessive transverse displacement.

To attain the above objective, the venetian blind comprises a top rail, a bottom rail, a bottom rail located below the top rail, two ladder ropes connected between the upper and bottom rails, and a plurality of slats positioned between the upper and bottom rails and disposed on the transverse portions of the ladder ropes. The ladder ropes each have a first vertical portion, a second vertical portion opposite to the first vertical portion, a plurality of transverse portions connected between the first and second vertical portions and arranged in an equidistant manner along the first and second vertical portions, and a plurality of loop portions connected to the first vertical portion. The slats each have a top surface, a bottom surface opposite to the top surface, a first long edge caught by the loop portions of the ladder ropes, a second long edge adjacent to the second vertical portions of the ladder ropes, two holes through the top and bottom surfaces and penetrated by the loop portions of the ladder ropes, two openings formed at the first long edge for allowing the loop portions to enter and exit, and two slots through the top and bottom surfaces and each communicating between the hole and the opening for guiding the loop portion to move from the hole to the opening or from the opening to the hole. The openings each have a width gradually decreasing toward the slot. In this way, the loop portion is easy to enter the slot through the opening. Further, a peripheral wall of each of the holes has a guiding surface and a positioning portion. When the slats are tilted from a horizontal position to a tilted position, the loop portions are moved along the guiding surfaces to the positioning portions, and when the slats are located at the tilted position, the loop portions are positioned in the positioning portions of the slats.

It can be seen from the above that with the holes, the openings and the slots of the slats, the venetian blind of the present invention allows the ladder ropes to be assembled with the slats conveniently and firmly without using other tools: meanwhile, the damaged slats are easily disassembled from the ladder ropes for repair or replacement. Further, the venetian blind of the present invention prevents the slats from excessive transverse displacement through the loop portions and the holes, such that the venetian blind of the present invention can eliminate traditional lift cords to provide a simple structure.

Preferably, the peripheral wall of each of the holes has two said guiding surfaces. When the slats are tilted from the horizontal position to the tilted position, each of the loop portions is moved along one of the guiding surfaces to the positioning portion.

Preferably, the positioning portion is formed at a junction of the two guiding surfaces. A distance between the two guiding surfaces gradually increases away from the positioning portion.

Preferably, the slots each have a first guiding section communicating with the hole and extending along a longitudinal direction of the slat, and a second guiding section connected with the first guiding section and communicating with the opening and extending along a width direction of the slat.

Preferably, a chamfer is formed at a junction of the first and second guiding sections to avoid interference between the loop portion and the slot.

Preferably, the loop portions each have two ends thereof connected to the first vertical portion of the ladder rope and located at the same side of the transverse portion of the ladder rope.

Preferably, the loop portions each have two ends thereof connected to the first vertical portion of the ladder rope and located at the opposite side of the transverse portion of the ladder rope.

Preferably, the two slots are arranged in a transversely symmetrical. In this way, it is easier for the slats to be positioned.

Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure.

Referring to <FIG> and <FIG>, a venetian blind <NUM> of the present invention comprises a top rail <NUM>, a bottom rail <NUM>, two ladder ropes <NUM>, and a plurality of slats <NUM> (the number is not limited herein).

The top rail <NUM> and the bottom rail <NUM> are arranged in an up-down manner.

The two ladder ropes <NUM> are connected between the top rail <NUM> and the bottom rail <NUM>. Each of the ladder ropes <NUM> has a first vertical portion <NUM>, a second vertical portion <NUM>, a plurality of transverse portions <NUM>, and a plurality of loop portions <NUM>. As shown in <FIG> and <FIG>, the first vertical portion <NUM> and the second vertical portion <NUM> are opposite to each other, and both have their respective tops extending into the top rail <NUM> to be connected with an angle adjusting mechanism (not shown) for adjusting the tilt angle of the slats <NUM>. Since the angle adjusting mechanism is known in the prior art and not the characteristic of the present invention, the detail thereof is omitted herein. The transverse portions <NUM> are connected between the first and second vertical portions <NUM>, <NUM> by means of sewing or weaving and arranged in an equidistant manner along the first and second vertical portions <NUM>, <NUM>. The loop portions <NUM> each have a first end <NUM> and a second end <NUM>. The first and second ends <NUM>, <NUM> are connected to the first vertical portion <NUM> by means of sewing or weaving and located at the same side or opposite side of the transverse portion <NUM>, as shown in <FIG> and <FIG>.

As shown in <FIG>, the slats <NUM> each have a top surface <NUM>, a bottom surface <NUM> opposite to the top surface <NUM>, a first long edge <NUM>, a second long edge <NUM> opposite to the first long edge <NUM>, two holes <NUM> through the top and bottom surfaces <NUM>,<NUM>, two openings <NUM> formed at the first long edge <NUM>, and two slots <NUM> through the top and bottom surfaces <NUM>, <NUM> and each have a first guiding section <NUM> communicating with the hole <NUM> and extending along the longitudinal direction of the slat <NUM>, and a second guiding section <NUM> connected with the first guiding section <NUM> and communicating with the opening <NUM> and extending along the width direction of the slat <NUM>, wherein the peripheral wall of each of the holes <NUM> has two guiding surfaces <NUM> (at least one is sufficient) and a positioning portion <NUM> formed at a junction of the two guiding surfaces <NUM>. A distance D between the two guiding surfaces <NUM> gradually increases away from the positioning portion <NUM>.

What needs to be added here is that the hole <NUM> can have different geometrical shapes, such as triangle, circular, semicircular, quadrangle or hexagon. In this embodiment, the hole <NUM> has a triangular shape.

To assemble the ladder rope <NUM> and the slats <NUM>, as shown in <FIG>, the slats <NUM> are parallel to each other and arranged between the top rail <NUM> and the bottom rail <NUM>, and further, each of the slats <NUM> is supported by the transverse portions <NUM> of the two ladder ropes <NUM> in such a way that the first long edges <NUM> of the slats <NUM> are adjacent to the first vertical portions <NUM> of the ladder ropes <NUM> and the second long edges <NUM> of the slats <NUM> are adjacent to the second vertical portions <NUM> of the ladder ropes <NUM>. Thereafter, the loop portion <NUM> of the ladder rope <NUM> is inserted into the second guiding section <NUM> of the slot <NUM> through the opening <NUM>, and then moved to the first guiding section <NUM> of the slot <NUM> from the second guiding section <NUM> of the slot <NUM>, and then penetrated into the hole <NUM> of the slat <NUM> from the first guiding section <NUM> of the slot <NUM>, so that the loop portion <NUM> of the ladder rope <NUM> is mounted around the first long edge <NUM> of the slat <NUM> to complete assembly of the ladder rope <NUM> and the slat <NUM>. What needs to be added here is that the openings <NUM> each have a width W gradually decreasing toward the slot <NUM> to permit the loop portions <NUM> to easily enter the openings <NUM>, and further, a chamfer <NUM> is formed at a junction of the first and second guiding sections <NUM>, <NUM> to make it easier for the loop portion <NUM> to move from the second guiding section <NUM> to the first guiding section <NUM> without interfering with the slot <NUM>.

It is worth mentioning that in this embodiment, each of the loop portions <NUM> of the ladder ropes <NUM> is penetrated into one of the holes <NUM> of the slat <NUM>. However, each of the loop portions <NUM> of the ladder ropes <NUM> can be penetrated into the holes <NUM> of the two adjacent slats <NUM>, as shown in <FIG>. Further, the slot <NUM> is not limited to be formed by the first guiding section <NUM> and the second guiding section <NUM>. As shown in <FIG>, the slot <NUM> can be formed in an inclined manner for guiding the loop portion <NUM> to move.

As the ladder rope <NUM> and the slat <NUM> are such assembled, the slat <NUM> is prevented from excessive transverse displacement, and further, since the slot <NUM> is in a reversed-L shape, even when the assembled slat <NUM> is lifted, lowered or tilted, the loop portion <NUM> of the ladder rope <NUM> inserted in the hole <NUM> is difficult to move into the first guiding section <NUM> of the slot <NUM>, thereby effectively preventing the loop portion <NUM> of the ladder rope <NUM> from accidentally coming off the slat <NUM>.

Replacement of a damaged slat <NUM> can be easily achieved by pulling the loop portion <NUM> of the ladder rope <NUM> inserted in the hole <NUM> of the damaged slats <NUM> out of the hole <NUM> through the slot <NUM> and the opening <NUM>, and having a new slat <NUM> assembled with the loop portion <NUM> of the ladder rope <NUM> as described above. The replacement is simple and rapid.

Moreover, when the slats <NUM> are tilted from a horizontal position P1 as shown in <FIG> to a tilted position P2 as shown in <FIG> and <FIG>, the loop portions <NUM> of the ladder ropes <NUM> are moved along one of the two guiding surfaces <NUM> to the positioning portions <NUM> (as shown in <FIG>) by the staggered arrangement of the holes <NUM> and the loop portions <NUM>. During movement of the loop portions <NUM> of the ladder ropes <NUM>, the slats <NUM> are aligned automatically to each other. Once the slats <NUM> are located at the tilted position P2 as shown in <FIG>, the loop portions <NUM> of the ladder ropes <NUM> are positioned in the positioning portions <NUM> of the slats <NUM>. At this time, each two adjacent slats <NUM> are closer to each other, thereby minimizing the interval therebetween that may allow light to leak in, and in turn improving the light-shading effect.

Claim 1:
A venetian blind (<NUM>) comprising:
a top rail (<NUM>);
a bottom rail (<NUM>) located below the top rail (<NUM>);
two ladder ropes (<NUM>) connected between the top and bottom rails (<NUM>, <NUM>), the ladder ropes (<NUM>) each having a first vertical portion (<NUM>), a second vertical portion (<NUM>) opposite to the first vertical portion (<NUM>), a plurality of transverse portions (<NUM>) connected between the first and second vertical portions (<NUM>, <NUM>) and arranged in an equidistant manner along the first and second vertical portions (<NUM>, <NUM>), and a plurality of loop portions (<NUM>) connected to the first vertical portion (<NUM>); and
a plurality of slats (<NUM>) positioned between the top and bottom rails (<NUM>, <NUM>) and disposed on the transverse portions (<NUM>) of the ladder ropes (<NUM>), the slats (<NUM>) each having a top surface (<NUM>), a bottom surface (<NUM>) opposite to the top surface (<NUM>), a first long edge (<NUM>) caught by the loop portions (<NUM>) of the ladder ropes (<NUM>), a second long edge (<NUM>) opposite to the first long edge (<NUM>) and adjacent to the second vertical portions (<NUM>) of the ladder ropes (<NUM>), two holes (<NUM>) through the top and bottom surfaces (<NUM>, <NUM>) and penetrated by the loop portions (<NUM>) of the ladder ropes (<NUM>), two openings (<NUM>) formed at the first long edge (<NUM>) for allowing the loop portions (<NUM>) to enter and exit, and two slots (<NUM>) through the top and bottom surfaces (<NUM>, <NUM>) and each communicating between the hole (<NUM>) and the opening (<NUM>) for guiding the loop portion (<NUM>) to move between the hole (<NUM>) and the opening (<NUM>), wherein a peripheral wall of each of the holes (<NUM>) has a guiding surface (<NUM>) and a positioning portion (<NUM>), and when the slats (<NUM>) are tilted from a horizontal position (P1) to a tilted position (P2), the loop portions (<NUM>) are moved along the guiding surfaces (<NUM>) to the positioning portions (<NUM>), and when the slats (<NUM>) are located at the tilted position (P2), the loop portions (<NUM>) are positioned in the positioning portions (<NUM>);
characterized in that
the openings (<NUM>) each have a width (W) gradually decreasing toward the slot (<NUM>).