GB2613138A

GB2613138A - Window blinds

Info

Publication number: GB2613138A
Application number: GB2113685.8A
Authority: GB
Inventors: Noone Paul
Original assignee: Manchester Mfg Group Ltd
Current assignee: Manchester Mfg Group Ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2023-05-31
Also published as: GB202113685D0

Abstract

A venetian blind 8 comprising a top casing 10, slats, a bottom rail 14, a slat guide means 16, 24, a flexible ladder means, two top mounting means 20A, 20B and two bottom mounting means 22A, 22B. The slat guide means 16, 24 is comprised of a guide line 16 and a guide line tensioning means 24; the top casing 10 comprises means to anchor the guide line 16 to the top casing 10, and at least one attachment to attach a first end of each flexible ladder means to the top casing 10. The two top mounting means 20A, 20B each comprise a window unit engaging means adapted to engage with the glazed window unit, and a casing engagement means which engages with and reversibly retains the top casing 10. The two bottom mounting means 22A, 22B each comprise a window unit engaging means which engage the window unit, and a guide line guide means. The guide line guide means are so configured that the guide line 16 may pass through the guide means and, when the guide line 16 is under tension, the orientation of the guide line 16 may be different either side of the guide means. The ends of the guide line 16 are attached to opposite ends of the tensioning means 24, the guide line extends, not in order, between a first and second end of the tensioning means 24, through the bottom mounting means 22A, 22B, through at least part of the bottom rail 14, through the slats 12, and through the top casing 10. The bottom rail 14 comprises means to anchor a second end of the or each flexible ladder means to the bottom rail 14. A window unit comprising the blind and a kit of parts is also claimed.

Description

WINDOW BLINDS

This invention relates to blinds for glazed windows, in particular to venetian blinds for use in connection with glazed windows units where it is desired that the structure of the venetian blind remains within a predetermined distance of the glazed portion of the window unit.

Glazed window units are typically comprised of a frame and a glazing portion wherein the glazing portion is supported by and retained in the frame. Such glazed window units are typically supported in a predetermined position by a support structure such as a wall or roof for fixed window units. Glazed window units may also form part of a door, in which circumstance the frame for the window unit may be fixed to or integral with the structure of the door. Such doors are typically attached to a support structure by one or more hinges, attached to at least a second door by one or more hinges, or retained within or on one or more, typically two, channels or tracks by means which allow the door or a portion of the door to move along the channels or tracks.

Typically, venetian blinds comprise a top casing, a number of slats, a bottom rail, a pulley mechanism, a pulley cord, at least two flexible ladder means, and a tilting mechanism.

The tilting mechanism is comprised of a first part which is housed within the top casing and a second part which is a longitudinally extending rod one end of which is attached to the first part of the tilting mechanism in a fashion which allows torque generated by rotation of the rod about its longitudinal axis to be transmitted to the first part of the tilting mechanism.

Each flexible ladder means is comprised of a pair of side elements with a number of rungs extending between the side elements. The side elements and rungs of each flexible ladder are generally formed from wires, cords, or tapes and there are the about the same number of rungs as there are slats. -2 -

Each flexible ladder has a lower end engaged with the bottom rail in a sliding or fixed fashion and an upper end which is engaged with the tilting mechanism.

Each slat is supported individually at or adjacent each end of the slat by a rung of a flexible ladder means. Additional flexible ladder means may support the slat between the ladder means at or adjacent each end of the slat.

The inclination of the slats may be adjusted by actuation of the tilting mechanism which causes movement of one or both side elements of each flexible ladder in a longitudinal direction relative to the other side element of that flexible ladder.

The pulley mechanism is engaged with at least one pulley cord which is typically a flexible wire, cord or tape, at least one end of which is engaged with the bottom rail. Actuation of the pulley mechanism causes the bottom rail to be lifted or lowered with the weight of the bottom rail being supported by the or each pulley cord. Lifting or lowering the bottom rail allows the gathering up or deployment of the slats respectively. Actuation of the pulley mechanism is typically achieved by use of one or more cords or the like hanging from the top casing which are pulled and or released by the user to raise or lower the bottom rail.

If a venetian blind is to be associated with a glazed window unit that venetian blind is typically fixed to the frame of the glazed window unit or to the structure to which the frame of the glazed window unit is attached. Typically attachment to that structure is in a region of that structure adjacent to the frame.

In some circumstances, for example where a number of glazed window units are part of a bi-fold, tri-fold or multi-fold door it is desired that the whole of the structure of a venetian blind used in connection with that door is always within a predetermined distance of the glazed portion of the door. This is desired because if the venetian blinds project too far from the glazed portion of the glazed window units they may interfere with each other and or damage each other when the individual doors are folded and are adjacent to each other.

It is also desirable that the structure of the venetian blind is so configured that the structure of the venetian blind is within a predetermined distance of the glazed -3 -portion of the door when a number of glazed window units are part of a set of sliding doors when the doors slide past each other. This is desirable because it can avoid the sliding of one door relative to an adjacent door damaging a blind on one or both of the sliding doors.

It is known to construct the glazed window units of bi-fold, tri-fold or multi-fold doors or sliding doors with double glazed glazing units where a venetian blind is located between the glazing sheets of an or each double glazing unit. This construction prevents any possibility of the blinds interfering with each other but has disadvantages. In particular, the manufacture of the glazed portion of such glazing units is expensive, and it is not possible to repair or maintain the blind without removing the glazed portion of the glazing unit from the door and deconstructing the glazing portion.

According to an aspect of the present invention there is provided a venetian blind suitable for use in connection with a glazed window unit which comprises a glazed portion, in which the venetian blind comprises a top casing, a number of slats, a bottom rail, a slat guide means, a number of flexible ladder means, two top mounting means and two bottom mounting means in which the slat guide means is comprised of a guide line and a guide line tensioning means, the top casing comprises means to anchor the guide line to the top casing, and at least one attachment means adapted to attach a first end of each flexible ladder means to the top casing, the two top mounting means each comprise a window unit engaging means adapted to engage with the glazed window unit, and a casing engagement means adapted to engage with and reversibly retain the top casing in engagement with the casing engagement means, the two bottom mounting means each comprise a window unit engaging means adapted to engage with the glazed window unit, and a guide line guide means, the guide line guide means are so configured that the guide line may pass through the guide means and, when the guide line is under tension, the orientation of the guide line may be different either side of the guide means, the ends of the guide line are attached to opposite ends of the tensioning means, -4 -the guide line extends, not in order, between a first and second end of the tensioning means, through the bottom mounting means, through at least part of the bottom rail, through the slats, and through at least a portion of the top casing, and the bottom rail comprises means to anchor a second end of the or each flexible ladder means to the bottom rail.

In some embodiments of this aspect of the present invention the tensioning means is a tension spring, in some embodiments the tensioning means is a helical spring made of spring steel or another appropriate material.

In some embodiments of this aspect of the present invention the tensioning means is located between the bottom mounting means. In such embodiments the guide line extends, in order, from a first end of the tensioning means, through a bottom mounting means, through at least part of the bottom rail from a first end to a first side port in a side of the bottom rail, through the slats, through the top casing from a first side port therein to a second side port therein, through the slats, through at least part of the bottom rail from a second side port in a side of the bottom rail to the second end of the bottom rail, through the other bottom mounting means, and to the other end of the tensioning means.

In some embodiments of this embodiment of this aspect of the present invention the guide line is comprised of first and second sub-guide lines with a first end of each sub-guide line being anchored to the top casing and the second end of each sub-guide line is attached to the tensioning means. Such a configuration works in the same fashion as the above embodiment with the exception that the portion of guide line extending between the first and second side ports of the top casing is replaced by the structure of the top casing. Such a configuration gives rise to the same advantages as when there is a single guide line.

In some embodiments of this aspect of the present invention the tensioning means is located within the top casing. In such embodiments the guide line extends, in order, from a first end of the tensioning means, through a portion of the top casing to and through a first side port in the top casing, through the slats, through at least part of the bottom rail from a first side port in a side of the bottom rail to a first end of the bottom rail, through a first then a second bottom mounting means, through at -5 -least part of the bottom rail from the second end of the bottom rail to a second side port in a side of the bottom rail, through the slats, through a second side port in the top casing, through a portion of the top casing, and to the other end of the tensioning means.

In some embodiments of this embodiment of this aspect of the present invention the guide line is comprised of first and second sub-guide lines with a first end of the first and second sub-guide lines being anchored to the first and second bottom mounting means and the second end of each sub-guide line is attached to the tensioning means. Such a configuration works in the same fashion as the above embodiment with the exception that there is no portion of guide line extending between the first and second bottom mounting means. Such a configuration gives rise to the same advantages as when there is a single guide line.

The guide line may be formed from a cord, string, tape, wire, coated wire or other similar flexible longitudinally extending material. It is desirable that the guide line has a surface that allows it to slide over elements of the bottom rail without damage to the guide line or the elements of the bottom rail.

An advantage of this aspect of the present invention is that the guide line of the slat guide extends from the top casing to the bottom mount means which has the effect that the slat guide means controls the position of the slats when the venetian blind of the present invention is in all configurations from extended, that is it covers part of or all of the glazed portion of the glazed window unit to fully retracted where it covers only a minimal part of the glazed portion.

In this aspect of the present invention the tension applied to the guide line by the tensioning means is such that the guide line will slide through the first and second rail guides when a user is pushing the bottom rail toward the top casing or the bottom mounting means and the guide line will not slide through the rail guides when no force is applied by a user to the bottom rail. This has the advantage that there are no hanging cords or the like needed to raise or lower the bottom rail. As such, there are no hanging cords which can get caught on any other blind, glazed window unit and or any other structure. -6 -

In some embodiments of this aspect of the present invention the bottom rail is longitudinally extending and comprises first and second ends, first and second longitudinally extending sides, and first and second rail guides, in which the first rail guide is configured to cause the guide line to pass through the first end of the bottom rail and out of the first side of the bottom rail via a first side port, and the second rail guide is configured to cause the guide line to pass through the second end of the bottom rail and out of the first side of the bottom rail via a second side port.

In some embodiments, the first side port is between the second side port and the second end, and the second side port is between the first side port and the first end.

The first and second rail guides are, in some embodiments, each a single unit comprising a channel in the rail guide extending between the first end and the first side port and between the second end and the second side port.

In other embodiments, the first rail guide is comprised of a first end guide and a first intermediate guide and the second rail guide is comprised of a second end guide and a second intermediate guide. The first and second end guides re-orient the guide line between an orientation in which the guide line passes along the bottom rail and an orientation in which the guide line passes from the end of the bottom rail to one of the bottom mounting means.

The first and second rail guides may, in some embodiments be formed from a polyoxymethylene (also known as acetal) plastic In some embodiments of this aspect of the present invention a flexible ladder means is anchored to the bottom rail at about the same longitudinal positions on the bottom rail as the first and second side ports. This has the advantage that the guide line and the flexible ladders are, as a result, in about the same position longitudinally along the slats which gives an aesthetically pleasing appearance to a user. -7 -

In some embodiments of this aspect of the present invention the top casing further comprises a tilting mechanism, each flexible ladder means is comprised of a first and second longitudinally extending side element and a number of rungs, in which each rung extends between and is attached to the first and second side elements, and the tilting mechanism comprises tilt means configured to cause the first or second side elements of each flexible ladder to move in a longitudinal direction relative to the other side element of that ladder. This arrangement allows the tilting mechanism to adjust the orientation of the slats of the blind and hence the amount of light that the blind lets through.

In some embodiments of this embodiment the tilting mechanism further comprises a tilt wheel and a connection means. The tilt wheel is positioned relative to the top casing so that a user may turn or apply torque to the wheel. The connection means extends between the tilt wheel and the tilt means and transmits torque applied to the tilt wheel by a user to the tilt means. That torque actuates the tilt means. The tilt wheel may be knurled on its outer circumference or otherwise configured to allow a user to gain a grip on the tilt wheel. The advantage of using a tilt wheel rather than the known system of using a longitudinally extending rod one end of which is attached to the first part of the tilting mechanism in a fashion which allows torque generated by rotation of the rod about its longitudinal axis to be transmitted to the first part of the tilting mechanism is that, in contrast to the rod, the tilt wheel cannot change position relative to the top casing and as such cannot move to a position away from the top casing and thus potentially interfere with adjacent blinds or glazed window units.

In some embodiments of this aspect of the present invention the window unit engaging means of one or both of the top and bottom mounting means is suitable for use in connection with a glazed window unit having a glazed portion and a frame within which the glazed portion is retained, and the window unit engaging means comprises a mounting plate, in which the mounting plate is configured and dimensioned to be reversibly inserted between a face of the glazed portion and the frame of the window unit. The mounting means of these embodiments are useful because it is known that many glazed window units are constructed with a frame supporting and retaining in position a glazed portion. In such a construction there is typically a seal material, such as an elastically deformable material, between the -8 -frame and the glazed portion. The mounting plate is dimensioned and configured to be slid along the face of the glazed portion and between the seal and the glazed portion. The elastic deformation of the seal holds the mounting plate in position. The mounting plate is, in some embodiments, configured so that with sufficient force the mounting plate can be withdrawn from between the frame and the glazed unit. In some embodiments the mounting plate comprises a tapered edge and a non-tapered portion. This allows relatively easy introduction of the tapered edge between the frame and the glazed portion and the gripping of the non-tapered portion by the elastically deformed seal.

In some embodiments of this aspect of the present invention the window unit engaging means of one or both of the top and bottom mounting means is suitable for use in connection with a glazed window unit having a glazed portion and the window unit engaging means comprises a bonding face which is adapted for adhesion to the glazed portion of the window unit by a suitable adhesive. In some embodiments such an adhesive is a UV curable adhesive.

In some embodiments of these aspects of the present invention the casing engagement means of each of the top mounting means comprises a pair of arms which are elastically deformable to move towards each other, and the top casing is configured to reversibly clip onto the arms. In some embodiments the cross section of the top casing includes a narrowed portion which the free ends of the arms of the casing engagement means have to deflect to pass through and the arms are so configured that the arms may substantially return to their un-deflected configuration once the free ends have passed through the narrowed portion.

In some embodiments of these aspects of the present invention the casing engagement means of each of the top mounting means are configured so that the engagement of the top casing onto the top mounting means requires the top casing to be moved toward the casing engagement means in a direction substantially parallel to the face of the glazed portion of the glazed window unit on which the top mounting means are mounted.

The use of the top mounting means configured to require the top casing to be moved toward the casing engagement means in a direction substantially parallel to -9 -the face of the glazed portion of the glazed window unit has further advantages for glazed window units which include a quadrilateral frame, which is typically square or rectangular. In such embodiments, the mounting plates can be inserted or adhered so that the top mounting means are in the corner of the frame and the top casing configured so that an edge of that casing sits very close to or substantially in contact with the portion of the frame that is substantially parallel to the top casing. This is because any movement or flexure of the top casing necessary for or caused by engagement of the top casing with the top mounting means is in a direction substantially perpendicular to the face of the glazed unit, As such, no allowance for that movement needs to be included in the relative positioning of the edge of the casing that sits very close to or substantially in contact with the frame that is substantially parallel to the top casing.

A further advantage of the embodiments that require the top casing to be moved toward the casing engagement means in a direction substantially parallel to the face of the glazed portion of the glazed window unit is that incorrect or incomplete engagement between the top casing and the top mounting means will not have an effect on the distance between the face of the glazed portion of the glazed window unit and the furthest part of the venetian blind of the present invention.

In some embodiments of this aspect of the present invention the blind further comprises a bottom casing, and each of the bottom mounting means further comprise a bottom casing engaging means.

An advantage of including a bottom casing is that the bottom casing can, once engaged with the bottom mounting means, help to prevent any movement for the bottom mounting means towards each other as a result of the tension in the guide line.

In some embodiments of these embodiments the bottom casing engagement means are so configured that the bottom casing is required to move toward the bottom casing engagement means in a direction substantially parallel to the face of the glazed portion of the glazed window unit. Such embodiments have all the same advantages as those discussed above for the equivalent top casing engagement means.

-10 -In some embodiments of this aspect of the present invention the top and bottom mounting means may be dimensioned to suit a predetermined configuration of glazed window unit frame. In particular, the top and bottom mounting means mayu be configured so that the top and or bottom casing (if present) is, once engaged with the top or bottom mounting means, held in a position such that the surfaces of the frame and the mounting means remote from the glazed portion are at substantially the same distance from the glazed portion.

In some embodiments of this aspect of the present invention the top and bottom mounting means are so configured that they are handed. That is the mounting means for use on a first side of the galazed window unit as it is orientated in use is a mirror image of the equivalent mounting means on the other side of the glazed window. In some embodiments, the left bottom mounting means has the same configuration as the right top mounting menas, and the left top mounting means the same configuration as the right bottom mounting means.

In some embodiments of this aspect of the present invention one or both of the top casing and the bottom casing (where present) are longitudinally extending and have a cross section substantially perpendicular to the longitudinal axis of the casing which comprises a portion which is substantially U or C shaped.

In some embodiments of this aspect of the present invention one or both of the top and bottom casing and or the bottom rail are formed from aluminium or unplasficised polyvinyl chloride (UPVC).

In some embodiments of this aspect of the present invention which are suitable for use in connection with a glazed window unit having a glazed portion and a frame within which the glazed portion is retained, one or both of the top casing and bottom casing Of present) comprises a first and second longitudinally extending side wall joined by a bridging portion at a first longitudinal edge of the first and second side walls, the second longitudinal edges of the first and second side walls are free, and the casing is configured so that when the casing is engaged with the casing engagement means of the top or bottom mounting means the second side wall sits adjacent to the glazed portion of the window glazing unit and the bridging portion is the portion of the casing furthest from the portion of the frame to which the casing is adjacent and substantially parallel. In some embodiments the first side wall is deeper than the second side wall. The depth of the first and second side walls is measured from the first to the second longitudinal edges of each side wall, that is the depth is measured in a direction substantially perpendicular to the longitudinal axis of the casing.

In some embodiments the first side wall is sufficiently deep that the second edge of the first side wall overlies a part of the frame to which the casing is adjacent and substantially parallel. Use of such a casing will result in a blind with a pleasing aesthetic because there will be no visible gap between the casing and the frame to which the casing is adjacent and substantially parallel. As a result, the appearance of the casing will be such that it appears to be a very good fit with the frame. The first side wall may be configured to match or compliment any contours on the surface of the frame to which the casing is adjacent and substantially parallel.

In some embodiments the longitudinal extent of the first side wall is greater than for the second side wall and the bridging portion of the casing. In such embodiments the portions of the first side wall that extend beyond the ends of the second side wall and the bridging portion overlie a part of the frame adjacent the longitudinal ends of the second side wall and bridging portion. As a result, again, the appearance of the casing will be such that appears to be a very good fit with the frame. The first side wall may be configured to match or compliment any contours on the surface of the frame that the longitudinal ends of the first leg overlies.

According to a second aspect of the present invention there is provided a glazed window unit comprising a glazed window unit having a glazed portion, and a venetian blind according to the first aspect of the present invention.

In some embodiments of the second aspect of the present invention the glazed window unit further comprises a frame within which the glazed portion is retained.

According to a third aspect of the present invention there is provided a kit of parts comprising a top casing, a number of slats, a bottom rail, a slat guide means, a number of flexible ladder means, two top mounting means and two bottom -12 -mounting means which can be used to construct a venetian blind according to the first aspect of the present invention.

The present invention will be further described and explained with reference to the accompanying drawings in which: Figure 1 shows a glazed window unit to which there is attached an embodiment of a venetian blind according to the first aspect of the present invention; Figure 2 shows a schematic view of certain elements of the venetian blind of Figure 1; Figure 3 shows a schematic view of an embodiment of the guide line of the venetian blind of Figure 1; Figure 4 shows a schematic view of a second embodiment of the guide line of the venetian blind of Figure 1; Figure 5 shows a first perspective view of an embodiment of a mounting means of the venetian blind of Figure 1; Figure 6 shows a second perspective view of an embodiment of a mounting means of the venetian blind of Figure 1; Figure 7 shows side view of an embodiment of a mounting means of the venetian blind of Figure 1; Figure 8 shows a second side view of an embodiment of a mounting means of the venetian blind of Figure 1; Figure 9 shows a cross section of an embodiment of the top casing of the venetian blind of Figure 1; and Figure 10 shows a cross section of an alternative embodiment of the top casing of the venetian blind of Figure 1.

With reference to Figures 1 to 3, a glazed window unit 2 is comprised of a frame 4 and a glazed portion 6. The frame 4 is rectangular and retains the glazed portion 6 in a fixed position.

Attached to the glazed window unit 4 is a venetian blind 8. The venetian blind 8 is comprised of a top casing 10, a number of slats 12, a bottom rail 14, a slat guide means 15, two flexible ladder means 18A, 18B, two top mounting means 20A, 208, and two bottom mounting means 22A, 22B.

-13 -The slat guide means 15 is comprised of a guide line 16 and a guide line tensioning means 24.

The guide line 16 is formed from a cord, string, tape, wire, coated wire or other similar flexible longitudinally extending material. The guide line tensioning means 24 is a helical tension spring.

The tensioning means 24 is located between the bottom mounting means 22A and 22B and the guide line 16 extends, in order, from a first end 26 of the tensioning means 24, through the bottom mounting means 22A, through a guide line guide means 38 located in the first end 30 of the bottom rail 14, through the bottom rail to a guide line guide means 40, through a first side port 34 in a side of the bottom rail 14, through a second aperture in each of the slats 12 where each second aperture is substantially in the same longitudinal position along the slat as the second ladder means 18B, through a second side port 48 in the side of the top casing 10, through a guide line guide means 46, along a portion of the top casing 10,through a guide line guide means 44, through a first side port 42 in the side wall of the top casing 10, through a first aperture in each of the slats 12 where each second aperture is substantially in the same longitudinal position along the slat as the first ladder means 18A, through a second side port 34 in a side of the bottom rail 14, through a guide line guide means 50, through the bottom rail 14, through a guide line guide means 52 in the second end 32 of the bottom rail, through the bottom mounting means 22B, and to the second end 28 of the tensioning means 24.

The tensioning means 24 maintains a desired tension in the guide line 16 and will absorb any increases in tension within the guide line 16, for example increases that may be expected when the venetian blind 8 is being adjusted by a user (on which more below), and thus protects the guide line from being stretched or damage to one or more of the guide line guide means.

The guide line guide means 38, 40, 50, 52, side ports 36, 42, 34, 48 and bottom mounting means 22A, 22B are all so configured that the guide line 16 can slide through or is in sliding engagement with those elements. One or both of the guide line guide means 44, 46 are, in the illustrated embodiment, configured to grip or -14 -engage with the guide line 16 and prevent the guide line 16 passing through one or both of the guide line guide means 44, 46.

When the deployment of the venetian blind 8 is to be adjusted by a user, that is when it is to be lowered or raised, the user will grasp the bottom rail 14 and impel the rail up towards the top casing 10 or down toward the bottom mounting means 22A and 22B. The guide line 16 will then slide through the first and second side ports 34, 36 and the guide line guide means 38, 52 of the bottom rail 14. The tension imparted to the guide line 16 by the tension means 24 will in part determine how easily the guide line slides through those elements of the bottom rail. The nature of the surface of the guide line 16 will also in part determine how easily the guide line slides through those elements of the bottom rail.

With reference to Figure 4, the Figure shows an alternative configuration of guide line 16 for some alternative embodiments of a venetian blind according to the present invention. The various elements that interact with the guide line 16 are the same elements as shown in Figure 3 and have the same numbering.

The slats 12 of the venetian blind 8 can be tilted in the same fashion as is known in known venetian blinds. Actuation of the tilting is achieved by a user turning a dial 54. The dial 54 is mechanically linked to a known venetian blind tilting mechanism housed in the top casing 10. The mechanical linkage is such that rotation of the dial is transmitted to the tilting mechanism.

The tension means 24 and the portions of the guide line 16 extending to the tension means from the bottom mounting means 22A and 22B may be covered by a bottom casing 56.

With reference to Figures 5 to 8, bottom mounting means 22A has a frame engagement portion 58 and a casing engagement portion 60. Frame engagement portion 58 is made up of a tapered portion 58A and a non-tapered portion 58B. The tapered portion 58A of the frame engagement portion 58 is dimensioned and configured to be easily introduced between the frame 4 and the glazed portion 6 of the glazed window unit 2. The non-tapered portion is dimensioned and configured -15 -To fit between the frame 4 and the glazed portion 6 of the glazed window unit 2 and to be held in that position by elastic deformation of the frame 4 and or any sealing material (not shown) located between the frame 4 and the glazed portion 6.

The casing engagement portion 60 includes a plate 62 on which is mounted a pair of engagement arms 64. The engagement arms extend in a direction substantially parallel to the plate 62 and are integral with the plate 62 for approximately half their length. The portion of the engagement arms 64 that is integral with the plate 62 is around the half of each arm that is closest to the other of the arms. The remainder of each arm is spaced from the plate 62 and is elastically bendable toward the other of the arms. Located between the free ends of the arms 64 is a stop means 66 which prevents bending of the arms 64 beyond a predetermined amount. The plate 62 also defines a guide line guide 68 and a slot 70 which allows the guide line to be introduced into the guide line guide 68 without having to thread the end of the guide line through the guide line guide.

The bottom mounting means 223 has a similar configuration to the bottom mounting means 22A with the exception that the engagement portion is attached to the opposite edge of the plate 62. The top mounting means 20A is of the same configuration as the bottom mounting means 22B, and the top mounting means 203 is of the same configuration as the bottom mounting means 22A.

In use the frame engagement portion top and bottom mounting means 20A, 203, 22A, 22B are introduced between the portion of the vertical side elements 4A of the frame 4 that is immediately below the corner between the vertical side elements 4A and the upper most horizontal element 4B and immediately above the corner between the vertical side elements 4A and the lower most horizontal element 4B. The mounting means are orientated so that the free ends of the arms 64 are adjacent the horizontal frame elements 4B.

With reference to Figure 9, the longitudinally extending top casing 10 has a first side wall 72 and a second side wall 74 joined by a bridging portion 76. The edges of the first and second side walls 72, 74 remote from the bridging portion 76 are free, that is not attached to anything. Upstanding from the surface of the side walls 72, -16 - 74 that face each other and adjacent the free edge of the side walls are longitudinally extending ridges 78.

When the top casing 10 is to be attached to the top mounting means 20A and 20B the second wall 74 is laid against the glazed portion 6 with the gap between the free edges of the side walls 72, 74 facing the mounting means 20A, 20B. The top casing 10 is slid toward the mounting means and the casing engagement means 60 enter the space between the side walls 72, 74. As the casing engagement means 60 enters that space the ridges 78 contact a face of the free end of the arms 64 and bend them toward the stop means 66. Once the ridges 78 have passed over the free end of the walls 72, 74 the arms 64 spring back and the top casing is then retained in position by the arms 64.

The bottom casing 56 has the same configuration as the top casing 10.

With reference to Figure 10, an alternative top casing 80 is shown. The top casing 80 has much the same structure and method of engagement with the mounting means as the top casing 10 described above with the exception that it has an overlap portion 82. The over lapping portion 82 is configured and dimensioned so that at least a part of face 84 of the overlap portion overlies a part of the horizontal frame element 4B.

Again, the bottom casing may have the same configuration as the top casing 80.

Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of the present invention. In other words, a system designed according to an embodiment of the present invention will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures.

Moreover, the whole of or selected features of one or more embodiments of aspects of the present invention as discussed herein are to be understood as being combinable with the whole of or features of other embodiments and such combinations are explicitly disclosed herein.

-17 -The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from this invention.

Claims

-18 -CLAIMS1 A venetian blind suitable for use in connection with a glazed window unit having a glazed portion, in which the venetian blind comprises a top casing, a number of slats, a bottom rail, a slat guide means, a number of flexible ladder means, two top mounting means and two bottom mounting means in which the slat guide means is comprised of a guide line and a guide line tensioning means, the top casing comprises means to anchor the guide line to the top casing, and at least one attachment means adapted to attach a first end of each flexible ladder means to the top casing, the two top mounting means each comprise a window unit engaging means adapted to engage with the glazed window unit, and a casing engagement means adapted to engage with and reversibly retain the top casing, the two bottom mounting means each comprise a window unit engaging means adapted to engage with the glazed window unit, and a guide line guide means, the guide line guide means are so configured that the guide line may pass through the guide means and, when the guide line is under tension, the orientation of the guide line may be different either side of the guide means, the ends of the guide line are attached to opposite ends of the tensioning means, the guide line extends, not in order, between a first and second end of the tensioning means, through the bottom mounting means, through at least part of the bottom rail, through the slats, and through the top casing, and the bottom rail comprises means to anchor a second end of the or each flexible ladder means to the bottom rail.
2 A venetian blind according to claim 1 in which the guide line is comprised of first and second sub guide lines with a first end of each sub guide line being anchored to the top casing and the second end of each sub guide line is attached to the tensioning means.
3 A venetian blind according to claim 1 or 2 in which the bottom rail is longitudinally extending and comprises first and second ends, first and second longitudinally extending sides, and first and second rail guides, in which the first rail guide is configured to cause the guide line to pass through the first end of the -19 -bottom rail and out of the first side of the bottom rail via a first side port, and the second rail guide is configured to cause the guide line to pass through the second end of the bottom rail and out of the first side of the bottom rail via a second side port.
4 A venetian blind according to claim 3 in which the first side port is between the second side port and the second end, and the second side port is between the first side port and the first end.
5 A venetian blind according to claim 3 or 4 in a flexible ladder means is anchored to the bottom rail at about the same longitudinal positions on the bottom rail as the first and second side ports.
6 A venetian blind according to any of claims 1 to 5 in which the top casing comprises a tilting mechanism, each flexible ladder means is comprised of a first and second longitudinally extending side element and a number of rungs, in which each rung extends between and is attached to the first and second side elements, and the tilting mechanism comprises tilt means configured to cause the first or second side elements of each flexible ladder to move in a longitudinal direction relative to the other side element of that ladder.
7 A venetian blind according to claim 6 in which the tilting mechanism further comprises a tilt wheel and a connection means, in which the tilt wheel is positioned relative to the top casing so that a user may turn the wheel, and the connection means transmits torque applied to the tilt wheel by a user to the tilt means, and that torque actuates the tilt means.
8 A venetian blind according to any of claims 3 to 7 when dependent on claim 3 or 4 in which the tension applied to the guide line by the tensioning means is such that the guide line will slide through the first and second rail guides when a user is pushing the bottom rail toward the top casing or toward the bottom mounting means and the guide line will not slide through the rail guides when no force is applied by a user to the bottom rail.
-20 - 9 A venetian blind according to any of claims 1 to 8 in which the window unit engaging means of one or both of the top and bottom mounting means is suitable for use in connection with a glazed window unit having a glazed portion and a frame within which the glazed portion is retained, and the window unit engaging means comprises a mounting plate, in which the mounting plate is configured and dimensioned to reversibly be inserted between a face of the glazed portion and the frame of the window unit.
A venetian blind according to any of claims 1 to 8 in which the window unit engaging means of one or both of the top and bottom mounting means is suitable for use in connection with a glazed window unit having a glazed portion and the window unit engaging means comprises a bonding face which is adapted for adhesion to the glazed portion of the window unit.
11 A venetian blind according to any of claims 1 to 10 in which the casing engagement means of each of the top mounting means comprises a pair of arms which are elastically deformable to move towards each other, and the top casing is configured to reversibly clip onto the arms.
12 A venetian blind according to any of claims 1 to 11 in which the casing engagement means of each of the top mounting means are configured so that the engagement of the top casing onto the top mounting means requires the top casing to be moved toward the casing engagement means in a direction substantially parallel to the face of the glazed portion of the glazed window unit on which the top mounting means are mounted.
13 A venetian blind according to any of claims 1 to 12 in which the blind further comprises a bottom casing, and each of the bottom mounting means further comprise a bottom casing engaging means.
14 A venetian blind according to claim 13 in which the bottom casing engagement means of each of the bottom mounting means are configured so that the engagement of the bottom casing onto the bottom mounting means requires the bottom casing to be moved toward the bottom casing engagement means in a -21 -direction substantially parallel to the face of the glazed portion of the glazed window unit on which the bottom mounting means are mounted.
A venetian blind according to any of claims 1 to 13 and or 14, in which one or both of the top casing and the bottom casing are longitudinally extending and have a cross section substantially perpendicular to the longitudinal axis of the casing which comprises a portion which is substantially U or C shaped.
16 A venetian blind according to claim 15 suitable for use in connection with a glazed window unit having a glazed portion and a frame within which the glazed portion is retained, in which the edge of the top casing and or bottom casing further comprises a portion that extends the edge of the top or bottom casing remote from the other of the top or bottom casing and remote from the glazed portion, away from the other of the top or bottom casing, and the extended portion is configured to overlie any gap between the casing and the portion of the frame adjacent the top or bottom casing.
17 A glazed window unit comprising of a frame, a glazed portion, and a venetian blind according to any of claims 1 to 16.
18 A kit of parts comprising a top casing, a number of slats, a bottom rail, a slat guide means, a number of flexible ladder means, two top mounting means and two bottom mounting means for construction of a venetian blind according to any of claims 1 to 16 and a set of instructions.