GB2525442A

GB2525442A - Improvements in or relating to window blinds

Info

Publication number: GB2525442A
Application number: GB1407346.4A
Authority: GB
Inventors: Darren Lock; Shaun Welsh
Original assignee: Hillarys Blinds Ltd
Current assignee: Hillarys Blinds Ltd
Priority date: 2014-04-25
Filing date: 2014-04-25
Publication date: 2015-10-28
Also published as: GB201407346D0

Abstract

A leveller 10 for a bottom bar (18, Fig. 3) of a suspended blind (19, Fig. 3) includes a bobbin 12 secured to an axle 11, wherein the axle 11 and bobbin 12 have a retainer with an aperture 13 for securing a suspension cord (22, Fig. 3). The bobbin 12 also has at least one flange 14, 16 having an edge feature that is lockably engageable in an aperture (24, Fig. 3) in a bottom bar (18, Fig. 3). The bobbin 12 can be locked in an aperture (24, Fig. 3) in a chosen rotational orientation, with a cord (22, Fig. 3) wound on the bobbin 12 to a selected extent. The leveller 10 permits easy adjustment of the orientation and hanging height of the bottom bar (18, Fig. 3). Also disclosed is a method for adjusting the height of a bottom bar assembly (18, Fig. 3).

Description

IMPROVEMENTS IN OR RELATING TO WINDOW BLINDS

The invention concerns improvements in or relating to window blinds including suspended slats and a bottom bar, and in particular but not necessarily to Venetian blinds. The term "s/at" as used herein includes both discrete slats that are formed independently of one another before assembly; and so-called fan-folded sheets in which blind elements are joined together by webs of material in the manner of concertina. Such slats are known to be made from a variety of materials including wood and various plastics and lightweight metals.

The invention furthermore is of utility in other designs of window blind, not necessarily including identifiable slats, that have a suspended bottom bar defining a lowermost edge of the blind. For convenience the blinds with which the invention may be used are herein referred to as "suspended bIinds' Venetian and other suspended blinds have been popular for many years, in part because of their practicality and also because in many situations the array of horizontal lines they present is visually appealing.

The basic design of a Venetian blind is well known and includes a series of horizontally extending, elongate slats that are supported one beneath another hanging from a top fixing rail. Guide cords extend downwardly from the top fixing rail through mutually aligned apertures in the slats, and terminate by being anchored in a bottom bar that defines the lower end of the blind. The guide cords together with suspension cords described below maintain the integrity of the blind: and the bottom bar provides a weight that increases the inertia of the blind and limits its tendency to swing e.g. when fixed adjacent an openable window through which the wind may blow.

At either end of the slats, and in some designs of blind also mid-way along their length, pairs of front and rear suspension cords extend from the top to the bottom of the blind, outside the slats. In register with each slat the suspension cords are interconnected by a respective flexible thread or line that underlies the adjacent slat and supports it from underneath.

The suspension cords are fed via a releasable clamp mechanism inside the fixing rail and have free ends that extend downwardly outside the fixing rail in a convenient position for manual grasping. A user may cause the entire blind to compress upwardly towards the fixing rail by pulling on the free ends of all the suspension cords simultaneously. This causes the blind to withdraw and as a result occupy less than the entire depth of a window.

The user also may manipulate the free ends of the suspension cords to cause the clamp mechanism to let the blind lengthen downwardly, thereby increasing the spacing between adjacent slats and causing the blind to occupy more of the window depth. A further mode of use involves adjusting the suspension cords influencing opposite ends of the blind in a differential manner that results in non-horizontal extension of the slats and bottom bar, In addition venetian blinds include a baissing screw, located in the fixing rail, that causes relative vertical movement of the suspension cords of each pair thereby causing the slats to tilt in a fore-and-aft direction under the influence of the flexible threads. As is well known this adjusts the extent to which the blind blocks off light transmitted via a window bay in which it is mounted. Typically the biasing screw is connected to an elongate screw rod that extends externally of the other parts of the blind to be easily manually gripped and rotated to cause such adjustment.

The assembly and installing of a venetian blind and indeed other types of suspended blinds often require care not least because a failure to achieve correct supporting of the slats (when present as individually suspended elements) and the bottom bar gives rise to an unsightly arrangement.

One particular problem derives from the need to ensure that the suspension cords are of the correct length such that the slats and bottom bar extend horizontally in use. The human eye is drawn to any arrangement in which members intended to extend horizontally are skewed. This effect is especially pronounced when there are other genuinely horizontal lines visible in the vicinity of an installed blind.

On assembly of a blind such as a Venetian blind in a factory the suspension cords are adjusted, before they are fixed in the bottom bar, to be of the same length. As a result the slats and bottom bar extend horizontally when the fixing bar is secured to a horizontal lintel.

In many installation locations however, even in new buildings, window lintels are not truly horizontal. Suspending a Venetian or other suspended blind from such a lintel results in a fixing bar, and hence a bottom bar and slats, that noticeably fail to achieve a horizontal

S

orientation. Moreover a careless installation technique can result in a non-horizontal mounting even when the lintel has been accurately built.

This can to some extent be compensated for by adjusting the suspension cords individually until the blind parts appear horizontal, but this is inconvenient to achieve (especially in a modern office in which many sets of blinds may require such adjustment). Moreover in the case of several suspended blind designs one mode of use involves releasing the clamp and allowing the suspension cords to run freely until they are fully extended. At such a point any lack of horizontal mounting of the fixing bar becomes visually accentuated in the slats and bottom bar.

Thus there is a need for improvements in the means available for levelling the bottom bars, and hence the slats or equivalent features, of suspended blinds. The invention seeks to address this requirement.

IS

According to the invention in a first aspect there is provided a leveller for a bottom bar of a suspended blind comprising an axle having secured thereto a bobbin, the axle andfor the bobbin including formed therein a retainer for securing of a suspension cord, the bobbin also including at least one bobbin flange having a periphery including an edge feature (e.g. a straight edge) that is lockably engageable in an aperture in a bottom bar for the purpose of locking the bobbin therein in in a selected rotational orientation with a cord wound on the bobbin to a selected extent.

Such a device advantageously provides a reliable anchor means that may be used to adjust the length of a blind suspension cord. The leveller may be made very cheaply from e.g. a plastics material.

In accordance with a second aspect of the invention there is provided a bottom bar for a suspended blind including a leveller as defined in accordance with the first aspect of the ao invention received in a leveller aperture formed therein that (a) journals the axle in a manner permitting release of the leveller from the aperture and (b) when the leveller is received therein is engaged by a peripheral edge feature of at least one said bobbin flange to prevent rotation of the leveller.

The invention is also considered to reside in a suspended blind, especially but not necessarily a Venetian blind, including a bottom bar according to the second aspect of the invention.

According to a third aspect of the invention there is provided a method of adjusting the height of a bottom bar according to the second aspect of the invention, the method including removing at least one said leveller from an associated said leveller aperture; S rotating the leveller so as to cause winding of the cord onto the bobbin or winding of the cord off the bobbin as desired; and replacing the leveller in the said leveller aperture such that its axle is journalled in the aperture and the periphery of at least one bobbin flange engages the aperture to prevent subsequent rotation of the leveller.

io Optional features of the invention are set out in the dependent claims appended hereto.

There now follows a description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying representations in which: Figure 1 is a plan view of a leveller in accordance with the invention; Figure 2 is a side elevational view of the Figure 1 leveller; and Figure 3 shows a bottom bar of a Venetian blind including a leveller as shown in Figures 1 and 2 in use.

Referring to the representations a leveller 10 may be made from e.g. a typical low-cost plastics material such as a nylon and includes an axle 11 in the form of a solid cylinder.

Axle 11 protrudes equally on either side of a bobbin part 12 to which it is rigidly secured by reason of (in the embodiment shown, although this need not necessarily be so) being rnoulded integrally with it.

The bobbin includes a retainer for a suspension cord of a suspended blind, as will be described in more detail hereinbelow.

The retainer in the preferred embodiment illustrated takes the form of a through-going aperture 13 that extends from one side of the axle to the other in the centre of the region of the bobbin part 12. In other embodiments of the invention the retainer may take other forms and may be e.g a clip or clamp. Moreover the retainer does not necessarily have to be located centrally in the axle as shown in the figures.

The bobbin includes at least one, and in the practical embodiment shown, two, bobbin flanges 14, 16.

The bobbin flanges 14, 16 are respective rigid hexagonal plates that are concentric with one another and the axle 11 on which they are secured as shown, and that are spaced mutually from one another. In the region between the flanges 14, 16 the axle 11 thickens to define an optional central bobbin disc 17 that is of larger diameter than the remainder of the axle 11. This facilitates winding of a cord onto the bobbin, as described below. Such a construction in addition lends itself to construction of the leveller as a moulded, once piece item as is preferred. The aperture 13 extends through the bobbin disc from one side to the other between the flanges 14. 16.

The hexagons of the respective bobbin flanges 14, 16 are in register with one another as illustrated. Although hexagonal bobbin flanges are preferred, other polygonal shapes are possible within the scope of the invention. Thus e.g. a pair of octagonal bobbin discs may be provided, with the octagonal shapes in register in like manner to the hexagonal flanges shown in the figures. The hexagonal or other polygonal shapes assist in locking the IS leveller in a chosen orientation when it is received in a leveller aperture described below.

A further possibility is for the periphery of each bobbin flange 14, 16 to define an irregular shape that includes a straight edge that also provides a locking function. Thus for example each flange 14, 16 may have an essentially circular outer periphery that incorporates a straight edge portion for leveller locking purposes. It is also possible for one or more bobbin flanges to have a completely circular outer periphery while providing a binding effect, that locks rotation of the leveller, on insertion into the aperture 24. All such arrangements lie within the scope of the invention.

Use of the leveller 10 of Figures 1 and 2 takes place in conjunction with a bottom bar 18 of a suspended blind as shown in Figure 3.

In Figure 3 the bottom bar 18 is part of a Venetian blind, but as explained the leveller of the invention is useable in conjunction with bottom bars of other designs of suspended blinds.

Figure 3 shows part of the length of a bottom bar 18, between the ends of a blind 19. Blind 19 is shown in its compressed configuration by reason of lateral suspension cords, of which one, 21, is visible in Figure 3, being tensioned as described above. Figure 3 illustrates the mounting of the leveller 10 of the invention with reference to a central suspension cord 22 that is illustrated in a slack condition.

A further lateral suspension cord that additionally is available to suspend and compress the blind 19 is not visible in Figure 3.

Bottom bar 18 includes formed in its lowermost edge 23 an in-use upwardly extending leveller aperture 24. Leveller aperture 24 is circular and is defined in part by a perforated plug 26 that is inserted therein to provide a liner for the leveller aperture 24.

Perforated plug 26 is moulded from a lightweight plastics material and includes at its in-use lowermost extent in a plug flange 27 that assists to terminate the aperture 24.

Plug flange 24 has formed therein a cross-shaped aperture 28 defining the perforation of plug 26.

The limbs of the cross of the aperture 28 are of differing widths as illustrated, such that two mutually opposed limbs 29 are wider than the other two mutually opposed limbs 31.

All four limbs 29, 31 of the cross shape define in-use upwardly extending chambers. The narrower limbs 31 are of a size into which the ends of the axle 11 respectively fit. When the axle is inserted into the limbs 31 in this way the bobbin flanges are accommodated within the orthogonal, wider limbs 29.

When thus received inside the leveller aperture 24 the straight edges of the bobbin flanges 14, 16 engage with the sides of the leveller aperture 24 and prevent rotation of the leveller 10. If however the leveller 10 is released downwardly out of the leveller aperture 24 the bobbin flange edges clear the material of the perforated plug 26 defining the interior of the aperture with the result that the leveller becomes rotatable relative to the plug 26 and aperture 24.

As shown in Figure 3 the in-use lower end of the suspension cord 22 extends through a transverse aperture 32 formed in the side of the plug flange 27. This end of cord 22 passes along a passage to extend through the retainer aperture 13 where a knot is tied. This causes retention of the cord 22 relative to the leveller 10.

In use of the leveller 10 to level a bottom bar 18 having plural such levellers fitted, and hence to level the slats of a blind, following assembly of the leveller as described in the foregoing paragraphs the fixing rail typically is screwed or otherwise secured to a window lintel. Adjustment of the orientation of the bottom bar to a horizontal orientation may then be effected by pulling one or more of the levellers 10 downwardly out ot the aperture 24 via the cross-shaped aperture 28.

As mentioned this frees the leveller to rotate. Rotation may be effected manually in order to wind a desired length of suspension cord onto or foo the bobbin disc 17 with the result that the effective length of each suspension cord becomes adjusted as desired. In the illustrated embodiment the suspension cord runs through the transverse aperture 32 during such adjustment. The presence of the aperture 32 however is optional, and guiding of the suspension cord may be achieved in other ways in further embodiments of the invention.

Once a particular suspension cord is as a result of this process of the requisite length the leveller 10 is reinserted into the aperture 24 via the cross-shaped aperture 28. This causes one or more of the straight edges of the bobbin flanges 14, 16 to engage an internal part of the perforated plug. This in turn causes binding of the leveller such that further rotation is prevented and the length of the suspension cord 22 becomes effectively fixed.

Optional features of the invention include for example snap retainers for the ends of the axle 11 inside the recesses defined by the narrower limbs 31 of the cross-shaped aperture 28; but in simple embodiments of the invention tension in the suspension cord following insertion of the leveller into the aperture 24 is sufficient to retain the former in the latter and give rise to the binding effect described.

The binding effect may be enhanced through the provision of features such as protrusions inside the perforation defined in plug 26.

Overall the leveller of the invention offers a low-cost, reliable means of adjusting the hanging heights and orientations of suspended blinds.

so The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention.

Claims

CLAIMS1, A leveller for a bottom bar of a suspended blind comprising an axle having secured thereto a bobbin, the axle and/or the bobbin including formed therein a retainer for securing of a suspension cord, the bobbin also including at least one bobbin flange having a periphery including an edge feature that is lockably engageable in an aperture in a bottom bar for the purpose of locking the bobbin therein in in a selected rotational orientation with a cord wound on the bobbin to a selected extent.
2. A leveller according to Claim 1 wherein the axle is a cylindrical shaft and wherein the retainer is a through-going aperture extending therethrough, the leveller including two bobbin flanges extending parallel to one another outwardly from the axle respectively on either side of the through-going aperture.is
3. A leveller according to Claim 2 wherein the bobbin flanges are each of the same design.
4. A leveller according to any preceding claim wherein the outer periphery of the or each bobbin flange is polygonal, especially hexagonal.
5. A bottom bar for a suspended blind including a leveller according to any preceding claim received in a leveller aperture formed therein that (a) journals the axle in a manner permitting release of the leveller from the aperture and (b) when the leveller is received therein is engaged by a peripheral edge feature of at least one said bobbin flange to prevent rotation of the leveller.
6. A bottom bar according to Claim 5 including a perforated plug secured to the bottom bar and defining an opening of the leveller aperture.
7. A bottom bar according to Claim 6 wherein the perforated plug is perforated in a cross shape.
8. A bottom bar according to any of Claims 5 to 7 including a cord of the suspended blind secured via the retainer to the leveller.
9. A bottom bar according to Claim 8 wherein a length of the cord is wound around the bobbin.
10. A bottom bar according to any of Claims 5 to 9 including a pair of levellers each according to any of Claims ito 4 received in a respective leveller aperture formed therein that (a) journals the axle in a manner permitting release of the leveller from the aperture S and (b) when the leveller is received therein is engaged by a peripheral straight edge of at least one said bobbin flange to prevent rotation of the leveller, the respective levellers being located at or near opposite ends of the bottom bar.
11. A suspended blind including a bottom bar according to any of Claims 6 to 10.
12. A suspended blind according to Claim ii wherein the blind is a Venetian blind.
13. A method of adjusting the height of a bottom bar according to Claim 8 or any preceding claim depending from ClaimS, the method including removing at least one said is leveller from an associated said leveller aperture; rotating the leveller so as to cause winding of the cord onto the bobbin or winding of the cord off the bobbin as desired; and replacing the leveller in the said leveller aperture such that its axle is journalled in the aperture and the periphery of at least one bobbin flange engages the aperture to prevent subsequent rotation of the leveller.
14. A leveller generally as herein described, with reference to and/or as illustrated in the accompanying drawings.
15. A bottom bar generally as herein described, with reference to and/or as illustrated in the accompanying drawings.
16. A suspended blind generally as herein described, with reference to and/or as illustrated in the accompanying drawings.
17. A method generally as herein described, with reference to and/or as illustrated in the accompanying drawings.