Patent Application
20060130981
This invention relates to window coverings, and in particular to a multi-tier venetian blind.
Venetian blinds are well known. Such blinds consist of a plurality of horizontal parallel slats supported on cord ladders. The ladders are suspended from a header rail mounted to the top of the window. A bottom rail is connected to the bottom ends of the ladders. A tilt control mechanism is typically provided in the header rail to tilt the slats to control the amount of light entering the room. Lift cords typically run from the bottom slat to a cord lock located in the header rail. The lift control mechanism permits the lifting or lowering of the bottom rail to control the portion of the window covered by the blind.
One of the problems encountered with prior art venetian blinds, particularly when installed in large windows, is that users want to control the amount of light entering the room through different sections of the window without lifting or lowering the blind. For example, it is often desirable to tilt the slats in the upper portion of a window to permit light to enter the room, while tilting the slats to a closed position in the bottom portion of the window for privacy reasons (i.e. to prevent people from looking into the building through the window.
Consequently, a number of two-tier venetian blinds have been developed in the prior art. Such blinds permit top and bottom sections or tiers of the slats to be tilted independently of each other. However, such prior art blinds are difficult to install, and are prohibitively expensive to manufacture. Accordingly, there is a need for an improved multiple tier venetian blind which is less expensive and can be manufactured from existing commercially available materials used for conventional single tier blinds.
According to a first aspect of the invention, a multi-tier venetian blind is provided. The venetian blind comprises first and second spaced apart ladders operatively suspended from a header rail. The ladders support a plurality of slats which comprise a first tier and a second tier below the first tier. The blind also comprises at least one lift cord and at least one adjustment cord. The lift cord is connected to a bottom slat and adapted to lift and lower the slats. The adjustment cord is connected to the first ladder at a predetermined point and is adapted to tilt the slats in the second tier by moving the first ladder at the predetermined point.
Preferably, the adjustment cord is connected to a loop located on the predetermined point of the first ladder.
According to a second aspect of the invention, a cord lock for controlling a first cord and a second cord is provided. The cord lock comprises:
a) a housing defining at least one pathway therein, the pathway comprising a first portion, a second portion and a third portion;
b) a retaining surface located in the housing; and
c) a first member and a second member slidably received in the pathway;
wherein the first member is movable between the first portion where the first cord moves freely and the second portion where the first member and the retaining surface cooperate to resist movement of the first cord;
wherein the second member is movable between the first portion where the second cord moves freely and the third portion where the first second and the retaining surface cooperate to resist movement of the second cord.
Preferably, the first and second cords are lift cords and adjustment cords, respectively, for a venetian blind.
In the accompanying drawings:
Continuing to refer to
The slats 32 rest on corresponding rungs 34 of each ladder 30a, 30b. Each slat 34 may include a pair of slots 36a, 36b. First and second lift cords 38a, 38b are secured to a heavier bottom slat 40 and run through the slots 36a, 36b of each slat 34. The lift cords pass into the header rail 12 through first openings 42a, 42b. The lift cords 38a, 38b pass through a cord lock 44 (described in detail below) and exit the header rail 12 through a second opening 46, where they are tied together to be controlled by the user.
A plurality of loops 50 are provided along the rear cords 52a, 52b of ladders 30a, 30b, respectively. As used herein, “rear” means the side of the blind 10 facing the window and “front” means the side of the blind facing the room. Preferably the ladders 30a, 30b are cord ladders and the loops 50 are cord loops attached to the ladders in any suitable fashion.
The loops 50 are preferably provided adjacent to each rung 34 of ladders 30a, 30b. It will be understood by those skilled in the art that loops 50 may be provided along front cords 54a, 54b of ladders 30a, 30b. Alternatively, no loops may be provided.
First and second adjustment cords 60a and 60b are each connected to a predetermined point 62 on the rear cords 52a, 52b of ladders 30a, 30b. The predetermined point 62 may be selected by the manufacturer and is located between a first upper tier 64 and a second lower tier 66 of the slats 32. Preferably, the adjustment cords 60a, 60b are tied to corresponding loops at the predetermined point 62, but may be connected to ladders 30a, 30b in any other suitable fashion. The corresponding loops are adjacent to the rungs 34 which support the uppermost slat 34 of the lower tier 66.
The adjustment cords 60a, 60b preferably run through all of the loops 50 of rear cords 52a, 52b above the predetermined point 62 and enter the header rail 12 through first openings 42a, 42b. The adjustment cords 60a, 60b pass through a cord lock 44 (described in detail below) and exit the header rail 12 through the second opening 46, where they are tied together to be controlled by the user.
Referring to
Continuing to refer to
Referring to
The lift cords 38a-d are secured to the bottom slat 40. Lift cords 38c and 38d pass through loops 50 on the rear cords 52c and 52d of ladders 30c and 30d. Lift cords 38a and 38b pass through loops 50 on the front cords 54a and 54b of ladders 30a and 30b.
Continuing to refer to
In this embodiment, two conventional cord locks 90, 92 are secured within the header rail 12. The first cord 90 lock locks and releases the lift cords 38a-d, and the second cord lock 92 locks and releases the adjustment cords 60a, 60b.
The operation of the first embodiment will now be described with reference to
When the entire blind 10 is in a completely or partially open position (the completely open position is shown in
The second embodiment is operated in the same manner as described above.
The venetian blind according to the present invention provides the advantage of manufacturing a multiple tier blind using standard off-the-shelf parts (i.e. standard cords and cord ladders) used for conventional single tier blinds, thereby reducing the cost and simplifying the manufacture of the multiple tier blind.
While the present invention as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and thus, is representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims.
