GB1581582A - Vertical louvre window blinds - Google Patents

Description

(54) VERTICAL LOUVRE WINDOW BLINDS (71) We, VENTOLITE NSB LIMITED, a British Company, of Kettering Road North, Northampton NN3 lHF, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to vertical louvre window blinds, in which the louvres are hung from a horizontal track and can slide along the track to enable the blind to be drawn across the window.

Conventionally, the top of each louvre is mounted on a louvre carriage which is slidably mounted in the track, and adjacent carriages are joined together by elongated links, each of which is rigidly fixed to one carriage and slidably mounted to an adjacent carriage and provided with an end stop to prevent disengagement from the second carriage, so that a limited amount of relative movement of the two carriages is permitted, dependent on the effective length of the link, which is the distance between the first carriage and the end stop.

When the blind is not in the drawn position, the louvres and thus the louvre carriages are bunched together at one end of the track or at both ends of the track in the case of a centre-opening blind. The blind is drawn by means of a pull cord which moves the first carriage at the or each end of the track towards the opposite end of the track. Once the first carriage has moved relative to the adjacent carriage by a distance equal to the effective length of the link, the end stop on the link engages the second carriage and pulls it and its associated louvre along the track. This second carriage likewise pulls the third carriage along the track, and so on until the carriages are in their closed positions.

Thus, the strip links perform a double function, they move the carriages along the track to enable the blind to be drawn and they also determine the spacing between adjacent carriages, and thus adjacent louvres when the blind is in the drawn position.

For convenience, the louvres for vertical louvre blinds are made in only a limited range of widths, for example two widths such as a 3+" width and a 5" width. However, windows come in a large variety of widths. Thus, it is necessary to be able to make up a blind to fit any desired width of window, from, say, either 3i" louvres or 5" louvres. Thus, if the louvres are to be evenly spaced as they preferably should be for the sake of aesthetics, the amount of overlap between adjacent louvres will have to be chosen to suit the width of the window.

The amount of overlap depends on the spacing of the louvre carriages, which depends on the effective length of the links.

Previously two types of link have been used. The first of these known types comprises a strip moulded from a plastics material and which has an integral end stop.

The effective length of the link is not variable and thus the spacing of the louvres in blinds assembled using such links cannot be chosen to suit individual windows. The result is that when the blind is drawn, the louvres tend to be unevenly spaced as adjacent louvres are not all separated by the full effective length of the links. The second known type of links are made from strips of spring steel. During manufacture of the blinds these strips are cut to a desired length and an end stop is formed by bending over the cut end. However, this operation has to be performed manually and is therefore time-consuming and expensive.

Also, spring steel is difficult to handle and more expensive than a plastics material such as polypropylene or nylon. Furthermore, once the spring steel strip has been cut, no further adjustment of its length is possible.

We have therefore designed a link for connecting adjacent louvre carriages of a vertical louvre blind, which link includes a movable end stop which therefore enables the effective length of the link to be varied.

According to the invention there is provided a vertical louvre blind for a window, comprising a track to be fitted horizontally at the top of the window, a row of louvre carriages slidable on the track, each pair of adjacent louvre carriages being joined by a link which permits a limited amount of relative movement between the said carriages and defines the maximum distance between the said carriages, each link comprising an elongated strip and an end stop the position of which on the strip can be varied to enable the maximum distance between the carriages to be variably chosen.

The strip and the end stop of the link are preferably formed from a synthetic plastics material.

The strip of the link is preferably formed with a toothed rack at one end and the end stop is preferably dimensioned to fit around the strip and has one or more teeth for engaging the rack.

Thus, a single link can be provided for each louvre width and its effective length can be adjusted by selecting the appropriate position of the end stop on the strip so that the louvre spacing when the blind is drawn is correct for any width of window.

The end stop can easily be fitted to the strip in the appropriate position using a jig, eliminating manual measurement of the link length.

One vertical louvre blind embodying the invention is illustrated by way of example in the accompanying drawings, in which: - Figure 1 is a cross-section of a top portion of a blind, taken through one of the louvre carriages; Figure 2 shows the link strip in side elevation; Figure 3 shows the link strip of Figure 2 in plan; Figure 4 is a detailed longitudinal section through the link showing the rack and the end stop; and Figure 5 is a perspective view showing how adjacent blind carriages are connected by the links.

The blind illustrated comprises a track 50 in the form of a rolled formed or extruded hollow section (e.g. of aluminium, steel, or a plastics material) which in use is mounted horizontally at the top of a window opening. Inside the track is mounted a row of hollow plastics louvre carriages 51, each carriage having a first passage 60 for receiving a pair of cords 70 for opening and closing the blind, and a second passage 62 for receiving a trefoil-section rod 49 mounted in a sleeve 53 which rotates with it and which is connected through gears 55, 62 to a louvre-engaging spindle which projects vertically downwards through an opening in the bottom of the carriage. Thus by rotation of the rod 49, the louvre can be rotated about a vertical axis to vary the amount of light admitted by the blind.

The above features of the blinds are all conventional.

Each pair of carriages 51, all of which are identical, are joined by a link 59, all of the links being identical. For example, the adjacent carriages 51A, 51B (Figure 5) are joined together by a link 59A in the form of a plastics strip which has an integral toothed rack 63 at a first end thereof. At the second end the strip has a pair of parallel stepped lateral flanges 64 and a small cylindrical projection 68. This second end of the link 59A is a snap fit in a slot 66 in the top of the first carriage 51A, with the flanges 63 fitting beneath two opposite projections 67, 67' at the sides of the slot and the projection 68 fitting into a hole (not shown) in the bottom of the slot.

The slot also houses, above the first link, a second link 59B which is identical to 59A and is slidable within the slot. The first link 59A is a sliding fit on the second carriage 51B which is adjacent to the first carriage, and the second end of the second link 59B is a rigid fit in a third carriage 51C, and so on. The toothed rack 63 is in engagement with a plastics end stop 69, which fits around the strip and has a plurality of teeth 71 for mating with the teeth of the rack. The position of the end stop along the strip can be varied depending on which teeth of the rack the stop engages. Moreover, the position of the end stop can be corrected if the end stop and the strip are inadvertently assembled with the end stop in the wrong position, by moving it in the direction shown by the arrow in Figure 4.

As the position of the end stop controls the spacing of the louvres when the blind is closed, the correct louvre spacing for any blind width can be readily adopted, i.e. the spacing which ensures that when the blind is drawn, all of the louvres are spaced apart by an equal distance, which is the maximum spacing permitted by the links.

WHAT WE CLAIM IS: - 1. A vertical louvre blind for a window, comprising a track to be fitted horizontally at the top of the window, a row of louvre carriages slidable on the track, each pair of adjacent louvre carriages being joined by a link which permits a limited amount of relative movement between the said carriages and defines the maximum distance between the said carriages, each link comprising an elongated strip and an end stop the position of which on the strip can be varied to enable the maximum distance between the carriages to be variably chosen.

2. A vertical louvre blind according to Claim 1, wherein the strip and the end stop are of synthetic plastics material.

3. A vertical louvre blind according to Claim 1 or Claim 2, wherein the strip is formed with a toothed rack at one end and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. carriages slidable on the track, each pair of adjacent louvre carriages being joined by a link which permits a limited amount of relative movement between the said carriages and defines the maximum distance between the said carriages, each link comprising an elongated strip and an end stop the position of which on the strip can be varied to enable the maximum distance between the carriages to be variably chosen. The strip and the end stop of the link are preferably formed from a synthetic plastics material. The strip of the link is preferably formed with a toothed rack at one end and the end stop is preferably dimensioned to fit around the strip and has one or more teeth for engaging the rack. Thus, a single link can be provided for each louvre width and its effective length can be adjusted by selecting the appropriate position of the end stop on the strip so that the louvre spacing when the blind is drawn is correct for any width of window. The end stop can easily be fitted to the strip in the appropriate position using a jig, eliminating manual measurement of the link length. One vertical louvre blind embodying the invention is illustrated by way of example in the accompanying drawings, in which: - Figure 1 is a cross-section of a top portion of a blind, taken through one of the louvre carriages; Figure 2 shows the link strip in side elevation; Figure 3 shows the link strip of Figure 2 in plan; Figure 4 is a detailed longitudinal section through the link showing the rack and the end stop; and Figure 5 is a perspective view showing how adjacent blind carriages are connected by the links. The blind illustrated comprises a track 50 in the form of a rolled formed or extruded hollow section (e.g. of aluminium, steel, or a plastics material) which in use is mounted horizontally at the top of a window opening. Inside the track is mounted a row of hollow plastics louvre carriages 51, each carriage having a first passage 60 for receiving a pair of cords 70 for opening and closing the blind, and a second passage 62 for receiving a trefoil-section rod 49 mounted in a sleeve 53 which rotates with it and which is connected through gears 55, 62 to a louvre-engaging spindle which projects vertically downwards through an opening in the bottom of the carriage. Thus by rotation of the rod 49, the louvre can be rotated about a vertical axis to vary the amount of light admitted by the blind. The above features of the blinds are all conventional. Each pair of carriages 51, all of which are identical, are joined by a link 59, all of the links being identical. For example, the adjacent carriages 51A, 51B (Figure 5) are joined together by a link 59A in the form of a plastics strip which has an integral toothed rack 63 at a first end thereof. At the second end the strip has a pair of parallel stepped lateral flanges 64 and a small cylindrical projection 68. This second end of the link 59A is a snap fit in a slot 66 in the top of the first carriage 51A, with the flanges 63 fitting beneath two opposite projections 67, 67' at the sides of the slot and the projection 68 fitting into a hole (not shown) in the bottom of the slot. The slot also houses, above the first link, a second link 59B which is identical to 59A and is slidable within the slot. The first link 59A is a sliding fit on the second carriage 51B which is adjacent to the first carriage, and the second end of the second link 59B is a rigid fit in a third carriage 51C, and so on. The toothed rack 63 is in engagement with a plastics end stop 69, which fits around the strip and has a plurality of teeth 71 for mating with the teeth of the rack. The position of the end stop along the strip can be varied depending on which teeth of the rack the stop engages. Moreover, the position of the end stop can be corrected if the end stop and the strip are inadvertently assembled with the end stop in the wrong position, by moving it in the direction shown by the arrow in Figure 4. As the position of the end stop controls the spacing of the louvres when the blind is closed, the correct louvre spacing for any blind width can be readily adopted, i.e. the spacing which ensures that when the blind is drawn, all of the louvres are spaced apart by an equal distance, which is the maximum spacing permitted by the links. WHAT WE CLAIM IS: -

1. A vertical louvre blind for a window, comprising a track to be fitted horizontally at the top of the window, a row of louvre carriages slidable on the track, each pair of adjacent louvre carriages being joined by a link which permits a limited amount of relative movement between the said carriages and defines the maximum distance between the said carriages, each link comprising an elongated strip and an end stop the position of which on the strip can be varied to enable the maximum distance between the carriages to be variably chosen.

2. A vertical louvre blind according to Claim 1, wherein the strip and the end stop are of synthetic plastics material.

3. A vertical louvre blind according to Claim 1 or Claim 2, wherein the strip is formed with a toothed rack at one end and

the end stop is dimensioned to fit around the strip, and has one or more teeth for engaging the rack.

4. A vertical louvre blind according to any preceding Claim and substantially as herein described, with reference to the accompanying drawings.