GB2241725A - Laminated window blind - Google Patents

Abstract

A Laminated Window Blind, is constructed from two or more sheets of clear plastic film (1) upon which are printed lines (2) in a particular and regular pattern. The plastic sheets (1) are supported by rods, which are mounted at each of their free ends, onto cranks. The edges of each sheet of plastic film running vertically from top to bottom, are protected from dust ingression by 'U' shaped channels. The cranks and rods and the top and bottom edges of the clear plastic sheets, are also protected from the ingress of dust, by means of tubular dust covers. This tubular dust cover has 8 slot one side of its entire length, to accept the crank mechanism and plastic sheets. A slot in the tubular dust cover on the bottom part of the blind is provided for the extended crank (7). End caps are fitted to the central rods to provide a pivot for the entire blind mechanism. <IMAGE>

Description

Iti#WNATh'D WINDOW 3MNt L ATED {lblCOvJ DIINE This invention relates to a Laminated Window Blind.

Sindow blinds are normally either of the roller type, or are made up of slats, as in the Venetian Blind. Roler blinds are line ted in their operation, to either being up or down. (open or closed? The Venetian Blind, on the other hand, may be partially opened or closed, by altering the angle of the slats. This allows varying amounts of light to pass between the slats, and permits glare to be shut out, without preventing less intense light from being admitted. Venetian Blinds will also allow light through at pre-determined angles, thus providing privacy without shutting out the light completely.

There are drawbacks to both roller and Venetian type blinds. Firstly, roller blinds are limited to being either up or down, and require the user to reach up a long way to pull the cord. This is especially difficult for the elderly or disabled, and when the return roller mechanism becomes worn, the blind is prone to recoiling upwards when it should be locked in the down position.

Venetian blinds are more versatile, in their mode of operation, but are very difficult to clean, due to the large number of individual slats which require to be wiped. Horizontal slats are prone to collecting large amounts of dust and grease in a fairly short period of time According to the present invention, there is provided, a Laminated Window Blind, comprising; two or more sheets of clear plastic film, upon which are printed lines of a pre-determined thickness. These lines are printed a pre-set distance apart on the clear plastic film, in such a manner that they coincide, when laid one upon the other in the same direction.The distance between the lines is calculated by multiplying the line thickness by the number of sheets of film to be used.From this total, a further ten percent is subtracted, to allow an overlap of lines to prevent light leakage due to inaccaracies. The sheets are laid over one another, in the form of a lamination, but are not fixed to each other.

At the top and bottom of each sheet of plastic a metal rod is inserted into a hem, running along the top & bottom edge of the film sheet. This metal rod is not fixed to the sheet, but is free to rotate inside the hem on the edge. Every sheet has two rods, one at the top edge and one at the bottom edge. Where a blind containing an odd number of sheets is to be made, (3,5,7,9 etc.,) the centre sheet would have rods of a longer length than the other sheets.

The mechanism which retains the plastic sheets and which allows the laminated layers to function as a blind, consists of; a rotating crank at the outer extremeties of the top and bottom of the combined layers of plastic film. Each crank is equipped with holes of similar diameter to the rods fitted in the film hems. These holes are alligned in a straight line across the crank, with one central hole to accept a central axle.

The free ends of each rod are fixed rigidly to the crank after insertion into the corresponding holes. This may be acheived by either adhesive or mechanical means. In the case of a blind with an even number of sheets, the central axle would have to be a separate unit from the rods supporting the sheets. Thus a further hole would be required in the centre of the crank to accept this axle. In the case of the blind having an odd number of sheets, the central sheet rod would form the axle, although larger diameter rod would be employed to support the full weight of the laminations. In the case of either odlor even numbers of sheets, the central axles must be of a larger diameter. The axles are not rigidly fixed to the cranks, but are free to rotate within them.The ends of the axles, which protrude beyond the cranks, are fixed to end caps.

The end caps form the top and bottom corners of the blind unit, and are connected to their opposite end caps respectively by means of a length of 'U' shaped plastic channel. This channel, running down each side of the blind unit, serves as a spacer, to keep tension in the sheets of plastic film, and also the 'U' shaped channel srves to gently grip the edges of the clear plastic film, preventing dust and debris from entering between the plastic sheets. This is acheived by inserting the layers of plastic film into the 'U' shaped channel, so that their edges are covered.

A trigger device, consisting of an extended crank, is positioned in the centre of the lower set of rods and is actuated by finger pressure.

Tubular dust covers are also provided and fit over the rods and cranks by means of a slot running along their length.

Referring to the drawing the Laminated Window Blind comprises; two or more layers of clear plastic film (1) printed with a pattern of lines (2).

Cranks (3) and Rods (4) are provided to support and move the sheets relative to one another. 'U' shaped channels (5) are fitted to the outer edges of the laminated layers of film to provide a dust seal. End caps (6) are attached to the ends of the central rods (4) to facilitate the free rotation of the cranks (3) & rods (4) about the central rods.

A central extendelerank (7) is also provided. This extended crank is fitted to the rods (4) in the centre of the lower edge of the complete unit.

The purpose of this extended crank is to allow single finger actuation of the blind by pressure on the crank.

in order to close the Laminated Blind central extended crank (7) is depressed. This pressure causes the rods (4) cranks (3) and plastic sheets (1) to move simultaneously. The cranks (3) rotate freely about the central rod allowing the rods (4) to follow the same arc. This movement causes a similar arc to be decribed by the sheets of film (1) which are freely attached to the rods. When this occurs a linear sliding movement is induced in the sheets of printed plastic film (1) whereby they are forced to move a proportionate distance to the distance traveled by the rods(4).

As this translation takes place the lines (2) printed upon the plastic film (1) move from being directly above and below one another to overlap their adjacent lin-~ on the nearest sheet thereby forming a barrier to incoming light. As shown in Figure 4.

The linear movement of the sheets (1) being of a proportionate distance to the circular movement of the cranks (3) produces a precisely metred shutter effect when the blind is viewed fron the front as shown in Figure 3 and figure 4. Figures; 1 & 2 show how the movement of the rods (4) and cranks (3) in conjunction with the 'U'shaped channels (5) acting as guides to the plastic film sheets (1) is converted into a linear translation over the working surface of the blind. Figure 3 illustrates how the line pattern (2) is calculated, including a slight reduction in the gap width to overcome any inaccuracies in the printing.

the 'U' shaped channel (5) is employed at the edges of the blind as shown in Figure 5. The purpose of this channel is to gently grip the edges of the sheets (1) so that no particles of dirt or dust may come between the film sheets and cause friction and damage. It may also, as illustrated in Figure 6, contribute to the even loading of the plastic sheets (1 by providing tension between the top and bottom rods (4J and cranks (3!. Also shown in Figure 6 is the tubular dust cover (8) of which there are two fitted to each blind. These prevent dust and debris from entering the gaps between the sheets (1) where they meet the rods (4).

The dust cover on the bottom edge of the blind is equipped with a slot (9! cut at right angles to the horizontal axis. This slot permits the extended crank (7 to protrude, so that it may be actuated by a small movement of the finger or thumb of the user.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which Figure 1 shows, in cross-section the relationship between the printed lines, when moved across one another by the crank mechanism.

Figure 2 shows in cross-section the operation of the crank mechanism.

Figure 3 shows the pattern of lines on a specific example of the blind, in the open position Figure 4 shows the pattern of lines on a specific example of the blind , in the closed position.

Figure 5 shows in cross-section the sheets of clear plastic with the 'U' shaped channel covering their edges.

Figure 6 shows in perspective the general features of the blind when fully assembled.

Claims (1)

1; A Laminated Window Blind comprising two or more sheets of clear plastic film, upon which lines are printed, and where the plastic film sheets are moved over one another by means of a crank or cranks.

2; A Laminated Window Blind as claimed in Claim 1 wherein the lines printed upon the clear plastic film are so proportioned as to overlap and form a shutter when the crank mechanism is operated.

3; A Laminated Window Blind as claimed in Claim 1 or Claim 2, wherein the gaps between the printed lines on each clear plastic sheet, are calculated by multiplying the chosen line width by the number of sheets to be used, then subtracting ten percent of the total.

4; Alaminated Window Blind as claimed in any preceding claim, wherein the printed lines on the said clear plastic sheets are vertical, horizontal curved or straight and of uniform width.

5; A Laminated Window Blind as claimed in any preceding claim, wherein a plastic or metal channel or channels are fitted to the outer vertical edges of the laminated clear plastic sheets to exclude dust and dirt.

6; A Laminated Window Blind as claimed in Claim 5, wherein the blind may be operated by depressing a single extended crank, positioned in the centre of the bottom edge of the blind.

7; A laminated Window Blind as claimed in any previous claim, wherein the printed lines on each clear plastic sheet, are translucent, opaque, or solid, dependent on the nature of application.

8; A Laminated Window Blind as claimed in Claim 7, wherein a number of clear plastic sheets, printed with line patterns, are moved in a linear manner, over one another to exclude or admit light 9; A Laminated Window Blind as claimed in any preceding claim, wherein patterns of dots, lines or circles are used as printed patterns on the clear plastic sheets, in such a manner as to form a complete image, logo or message when the blind is either open or closed or partly open.

10; A Laminated Window Blind,-substantially as decribed herein with reference to Figures 1 - 6 of the accompanying drawing.