CA2995258A1 - Bottom rail for a blind covering - Google Patents

Abstract

The invention relates to a bottom rail for attachment to an edge of a sheet of blind fabric, such as the type of fabric included in a roller blind. The bottom rail comprises an elongate front member and an elongate rear member, wherein the front member and the rear member are configured to fasten together by friction fit and clamp the edge of the blind fabric therebetween.

Description

BOTTOM RAIL FOR A BLIND COVERING
FIELD OF INVENTION
[0001] The present invention relates to the field of blinds, particularly bottom rails for window blinds.

[0002] In one form, the invention relates to a bottom rail for the fabric component of a roller blind.

[0003] It will be convenient to hereinafter describe the invention in relation to a bottom rail for a roller blind, however it should be appreciated that the present invention is not limited to that use only and could be used for other types of fabric blinds.
BACKGROUND ART

[0004] It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention.
Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor.
Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein.

[0005] Blinds are commonly used to provide a covering for openings in a wall, such as windows or glass doors. Typically, they comprise a rectangular sheet of fabric that is used for privacy or to block out light. The upper edge of the fabric is attached to, and hangs vertically down from a head rail mounted to a wall, a round rotating tube or other fixed structure above the opening.

[0006] The extent to which the fabric hangs down to cover the opening can be adjusted for privacy or to control the amount of light entering a room. For example, the pleated fabric of a Roman blind is adjusted by a user manipulating a system of pull strings which extend vertically from the head rail and can raise or lower the fabric. The sheet of fabric of a roller blind is adjusted by a user pulling a looped cord that causes the fabric to wind on or off a cylinder. Pulling on one side of the loop causes the cylinder to rotate in one direction and wind up the fabric, lifting the blind. Pulling on the other side of the loop causes the cylinder to rotate in the other direction and wind off the fabric, lowering the blind.

[0007] The lower edge of the fabric is typically attached to a bottom rail, which is elongate, straight and has some weight. This helps the fabric to hang straight, makes it look neat and resists flapping in a breeze. The weight of the bottom rail also contributes to smooth adjustment and smooth operation of a roller blind.

[0008] In the past, during manufacture of the blind the bottom rail has been attached to the fabric by application of glue, tape or staples. For example, the fabric may be attached using a single strip of double sided adhesive tape on each side of the bottom rail. The fabric is folded around and adheres to both sides of the rail.
Alternatively, a plastic spline may be glued, taped or stapled on the fabric and then folded and slid into a recess in the bottom rail.

[0009] One of the problems associated with the prior art methods for attaching the bottom rail to the fabric is that they are labour intensive ¨ particularly when they require steps such as correct positioning of the tape, adhering the spline and stitching operations. These steps slow production and increase production costs.

[0010] Another problem is that some prior art techniques can cause puckering of the fabric, which diminishes appeal to consumers.

[0011] Attempts have been made to overcome these problems. For example, US
patent application 2011/0049071 describes a specific configuration of bottom rail. The edge of a sheet of blind fabric is inserted into a longitudinal slot in the rail, then an elongate insert is pushed into the slot to trap and retain the edge of the blind fabric.

SUMMARY OF INVENTION

[0012] An object of the present invention is to provide a simplified method or device for the incorporation of a bottom rail in a blind.

[0013] A
further object of the present invention is to alleviate at least one disadvantage associated with the related art.

[0014] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems.

[0015] In a first aspect of embodiments described herein there is provided a bottom rail for attachment to an edge of a sheet of blind fabric, the bottom rail comprising:
- an elongate front member, - an elongate rear member, wherein the front member and the rear member are configured to fasten together by friction fit and clamp the edge of the blind fabric therebetween.

[0016] In a particularly preferred embodiment the bottom rail comprises:
- an elongate front member having a first internal surface comprising one or more front flanges, and - an elongate rear member having a second internal surface comprising one or more rear flanges.

[0017]
Preferably, the edge of the blind fabric is clamped between at least one front flange on the front member and at least one correspondingly located rear flange on the rear member.

[0018] Typically, in a preferred embodiment the projection of front flanges and rear flanges is approximately perpendicular from an internal surface. Typically, when the front member and rear member are engaged, part of the surface of each corresponding front flange and rear flange are adjacent and the blind fabric is clamped therebetween.
The surfaces of the flanges may be slightly curved surface or otherwise contoured to maximise the clamping effect

[0019] Preferably, the front member and the rear member of the rail are held together by friction fit between at least one front flange on the front member and at least one correspondingly located rear flange on the rear member. For example, the front flange may include small teeth which interlock with small teeth on a rear flange.

[0020] In a particularly preferred embodiment one pair of flanges hold the front and rear members in engagement and a separate pair of flanges clamp the material.

[0021] Preferably the front member and the rear member comprise lengths of extruded material such as polymer or metal.

[0022] In another aspect of embodiments described herein there is provided a method of attaching the aforesaid bottom rail to an edge of a sheet of blind fabric, the method comprising the steps of:
locating the edge of the fabric between the elongate front member and elongate rear member, and subsequently, applying pressure to fasten the front member to the rear member by friction fit and retain the edge of the blind fabric therebetween.

[0023] In this manner the bottom rail can be quickly fitted to the fabric either manually or more preferably, as part of a mechanised blind assembly process.

[0024] Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention.

[0025] In essence, embodiments of the present invention stem from the realization that a bottom rail could be configured to conveniently clamp on to the edge of blind fabric.

[0026] Advantages provided by the present invention comprise the following:
= allows blind fabric to be securely attached to the bottom rail without time consuming or labour intensive alignment, stapling, gluing or sewing steps, = manufacturing process requires only a small inventory of parts and materials, = the bottom rail may be removed from the fabric by snapping the two rail members out of frictional engagement, and.
= allows a consumer to have a choice of appearance of the bottom rail, such as, a curved edge or a flat edge appearance.

[0027] Further scope of applicability of embodiments of the present invention will become apparent from the description given hereinafter. However, it should be understood that the description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this description.
BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present application may be better understood by those skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which:
FIG. 1 illustrates a prior art method for attachment of a bottom rail 1 to the edge of a fabric blind 3 using a single strip of double sided tape 5.

FIG. 2 illustrates another prior art method for attachment of a bottom rail to the bottom edge of a fabric blind 7 by wrapping around a rod 9 of square cross-section and securing the blind fabric 7 using stitching 11.
FIG. 3 illustrates another prior art bottom rail and method of use as described in US patent application 2011/0049071. FIG 3A illustrates blind fabric 15 extending down from the main body of the blind before forming a tight fold in a fold slot 17 in the rail 13. The fabric 15 is imprisoned by a rod 11 that runs the length of the fold slot 17. The fabric 15 backs out through the opening of the slot 17, then folds over the back of the rail 13 until the edge of the fabric 15 is located in a main slot 19. An insert 21 can be snapped into place in the slot 19 to cover and secure the edge of the fabric 15. FIG 3B depicts the same bottom rail as FIG 3A, assembled using a slightly different method such that the blind fabric 15 folds over the front of the rail 13 until the edge of the fabric 15 is located in main slot 19.
FIG. 4 is a view of one embodiment of the bottom rail of the present invention when the front member 31 and rear member 33 are disengaged (FIG. 4A), when the front member 31 and rear member 33 are engaged (FIG. 4B) and when the front member 31 and rear member 33 are clamping the edge of blind fabric 40 (FIG. 4C).
FIG. 5 is a perspective view of the bottom rail of FIG. 4A when the front member 31 and rear member 33 are disengaged.
DESCRIPTION

[0029] As mentioned above, FIGS 1 to 3 illustrate bottom rails of the prior art while FIGS 4 and 5 illustrate embodiments of the present invention.

[0030] For purposes of description herein, the terms "upper," "lower,"
"right," "left,"
"rear," "front," "vertical," "horizontal," "interior," "exterior," and derivatives thereof shall relate to the invention as oriented in FIG. 5. Typically, when the bottom rail of FIG. 5 is in use in a blind hanging on a window, the longitudinal axis it would horizontal (ie extending in the direction of the x-axis), the fabric would be hanging vertically (ie the plane of the fabric would be in the direction of, or coplanar with, the y-axis).

[0031] However, it is to be understood that the invention may assume various alternative orientations, such as during manufacture, and except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawing, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. Additionally, unless otherwise specified, it is to be understood that discussion of a particular feature of component extending in or along a given direction or the like does not mean that the feature or component follows a straight line or axis in such a direction or that it only extends in such direction or on such a plane without other directional components or deviations, unless otherwise specified.

[0032] FIG 4 and 5 illustrate the present invention comprising an elongate front member 31 and an elongate rear member 33. The elongate front member has a curved, convex surface for aesthetic effect, but many other desirable aesthetic effects could alternatively be used.

[0033] In this embodiment the front member 31 has a first internal surface comprising four front flanges 35, 37, 39, 41. The rear member 33 has a second internal surface comprising four rear flanges 43, 45, 47, 49. The flanges project more or less perpendicularly from the internal surface, however other angles of projection may also be suitable provided that they bring corresponding pairs of front and rear flanges into sufficiently close proximity.

[0034] FIG. 4B illustrates the front member 31 engaged with the rear member 33 and shows the friction fit between projecting front flanges 39, 41 and corresponding projecting rear flanges 47, 49. The corresponding front flange/rear flange pairs (39/47, 41/49) are held together by friction fit aided by series of teeth 53, 57 on the front flanges which interlock with a series of teeth 51, 55 on the rear flanges 51. This enables the front member 31 and rear member 33 to be pressed together and remain engaged.
If necessary, it may be possible to apply pressure in the opposite direction to overcome the frictional engagement between teeth and disengage the front member 31 and rear member 33.

[0035] It will be readily apparent to the person skilled in the art that alternative configurations may be suitable for frictional engagement of the front member 31 with the rear member 33. Typically, the front member or rear member are formed by extrusion of polymer or a metal and elongate members with many different numbers and configurations of front flanges and rear flanges may be suitable.

[0036] FIG. 4C shows the engagement of FIG. 4B with the fabric edge 40 of a blind clamped between the front member 31 and the rear member 33 of the bottom rail.
The fabric 40 is clamped where front flanges 35, 37 contact corresponding rear flanges 43,45. In this embodiment the rear flanges have slightly curved surfaces where they contact a front flange to enhanced the clamping effect although it is readily apparent that the clamping effect may be enhanced by a wide range of complementary configurations where the surface of a front flange meets a corresponding rear flange.

[0037] FIG. 5 is a perspective view of the arrangement shown in cross section in FIG.
4B. Forming the front member and the rear member as an extrusion has the added advantage that the members may be readily cut to any convenient and useful length.

[0038] Attaching the aforesaid bottom rail to an edge of a sheet of blind fabric is relatively easily achieved by:
(i) locating the edge of the fabric 40 between the elongate front member 31 and elongate rear member 33 as depicted in FIG 4c, and subsequently (ii) subsequently applying pressure to bring front flanges 53 and 57 into contact with the corresponding rear flanges 51 and 55 so that the front member 31 and the rear member 33 are held together by friction fit, while (iii) the edge of the blind fabric 40 is clamped between front flanges 35 and 37 of the front member 31 and corresponding rear flanges 43 and 45 of the rear member.

[0039] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s).
This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.

[0040] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive.

[0041] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims.
Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures.

[0042] "Comprises/comprising" and "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', 'includes', 'including' and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims (5)

10

1 . A bottom rail for attachment to an edge of a sheet of blind fabric, the bottom rail comprising:
an elongate front member, an elongate rear member, wherein the front member and the rear member are configured to fasten together by friction fit and clamp the edge of the blind fabric there between.

2. A bottom rail according to claim 1 wherein, the elongate front member has a first internal surface comprising one or more projecting front flanges, and the elongate rear member has a second internal surface comprising one or more projecting rear flanges.

3. A bottom rail according to claim 2 wherein the edge of the blind fabric is clamped between at least one front flange on the front member and at least one correspondingly located rear flange on the rear member.

4. A bottom rail according to claim 2 wherein the front member and the rear member of the rail are held together by friction fit between at least one front flange on the front member and at least one correspondingly located rear flange on the rear member.

5. A method of attaching the aforesaid bottom rail to an edge of a sheet of blind fabric, the method comprising the steps of:
locating the edge of the fabric between the elongate front member and elongate rear member, and subsequently, - applying pressure to fasten the front member to the rear member by friction fit and retain the edge of the blind fabric therebetween.