CORD GUIDE FOR A BLIND

Abstract: A cord guide (1) for a blind includes a main body with a through bore (4). A pin (5), preferably of metal, overlies the bore (4) to provide a low-friction surface against which an operating cord (3) for the blind may move. The cord guide (1) is preferably retained in a blind rail of the blind by means of a camming action. An end cap for a blind rail includes an outer surface having a pair of arms depending perpendicularly therefrom. The end cap may be a friction fit in the end of a blind rail, or may include latching means. The end cap includes bores through which an operating cord may be passed, and a channel to receive a pin, preferably of metal, over which the cord may pass.

Description: CORD GUIDE FOR A BLIND The present invention relates to blinds, in particular to pleated blinds, and to components thereof. Blinds of this type are generally used at windows or in conservatories or the like to provide shading from the sun, or to prevent the interior of a room or the conservatory from being visible from the outside, as may particularly be required at night. Pleated blinds usually consist of blind rails, that is, a head rail and a bottom rail, and one or more cords which are used to raise or lower the bottom rail with respect to the head rail. An expandable and collapsible pleated shade is arranged between the head rail and the bottom rail so as to expand or collapse along predetermined fold lines when the bottom rail is raised or lowered. The predetermined fold lines usually lie parallel to the head rail and bottom rail. The pleats of the blind are usually manufactured to be of equal size within normal manufacturing tolerances. More complex blinds may include a third, or even a fourth, rail disposed between the head rail and the bottom rail and moveable between the head rail and the bottom rail. In this way, different types of shade may be provided respectively above and below the third rail. For example, a completely opaque shade may be used at night to fully obscure the window or conservatory panel, and a semi-opaque shade may be used during the day to provide shade from the sun. An alternative type of blind may also include a head rail and a bottom rail and one or more cords used to raise or lower the bottom rail, with the shade provided by a series of strips of resilient material supported on the cords generally parallel to the head rail, across the width of the window. The strips may be tiltable with respect to the horizontal to vary the degree of shading. As will readily be appreciated, blinds of this type rely for their operation on the cords which are used to support and adjust the shades and the bottom rail. In order to provide the desired shading effects, the routing of these cords within the head rail, bottom rail, optional third or fourth rail and through the shade can be quite complex, with the cords required to move smoothly and freely with respect to the rails. A particular source of problems has been the points where the cord passes into or out of a rail through a hole in the rail and where, in many cases, the cord is required to change direction by, say, 90°. Clearly, passage of the cord through such holes causes friction between the rail and the cord which causes wear on the cord and can result in jamming of the blind mechanism which is not easily rectifiable. This has been alleviated to some extent by providing plastic grommets or the like in the holes, but the grommets and the cord are still subject to wear with use, mainly due to friction between the cord and the grommet and problems still occur. For example, where a blind is supported by more than one cord, one of the cords may become jammed, and movement of the other cord or cords then causes parts of the blind to no longer lie parallel with the head rail. The blind may not then easily be repaired by the user and specialist attention may be required. Also, the use of grommets and the like is inconvenient in manufacture, since they require a force-fit into the blind rail. A further disadvantage of using grommets or the like is that different types of component may be required for different types of blind or different locations with the blind, which increases manufacturing cost and complexity. For example, grommets for different situations may have different curvatures or "lead-in" cones where the cord is required to turn through a corner. Also, the tools used during manufacture, for example the punches used to form the holes in the rails, are subject to wear so that the holes are not correctly sized and a proper fit between the hole and the grommet is not guaranteed. The present invention seeks to at least partially alleviate or overcome the above problems. Accordingly, a first aspect of the present invention provides a cord guide for a blind comprising a main body portion engageable with a blind rail, a through bore to receive one or more cords, and a pin, preferably a metal pin, overlying the through bore substantially perpendicular to the axis of the through bore. Most preferably, the pin passes through the axis of the bore. By means of the invention, a cord passing through the cord guide has limited contact with the walls of the bore, so that wear and friction on the cord and the walls of the bore are reduced. The cord is routed around a corner by passing the cord over the pin. Friction and wear caused by movement of the cord over the pin are significantly reduced as compared with passing the cord through a conventional grommet, so that the blind may operate more smoothly and reliably. In one preferred embodiment of this aspect of the invention, the cord guide includes oppositely disposed camming surfaces operative to engage upon rotation of the cord guide with opposed walls of a blind rail. In this way the cord guide may more readily be located in its use position in the blind rail and a disadvantageous force-fit is not required. In a second aspect of the invention, there is provided a cord guide for a blind comprising a main body portion, a through bore to receive one or more cords, oppositely disposed camming surfaces operative to engage, upon rotation of the cord guide, with opposed walls of the blind rail and engagement surfaces by means of which the cord guide may be rotated. In this way the cord guide may more readily be located in its use position in the blind rail and a disadvantageous force-fit is not required. In one preferred embodiment of this aspect of the invention, the cord guide further comprises a pin, preferably a metal pin, overlying the through bore substantially perpendicular to the axis of the bore. Most preferably, the pin passes through the axis of the bore. By means of this embodiment of the invention, a cord passing through the cord guide has limited contact with the walls of the bore, so that wear and friction on the cord and the walls of the bore are reduced. The cord is routed around a corner by passing the cord over the pin. Friction and wear caused by movement of the cord over the pin are significantly reduced as compared with passing the cord through a conventional grommet, so that the blind may operate more smoothly and reliably. In a particularly preferred construction of these aspects of the invention, the cord guide comprises a channel to receive the pin, and more especially the cord guide comprises upstanding formations diametrically opposed with respect to the through bore and each including a channel portion to receive respective ends of the pin. The pin may be retained in the cord guide by moulding integrally with the cord guide, or the channel portions may be constructed so that the pin is a "snap fit" when pressed into them. Most preferably, the cord guide (or each upstanding formation) is so sized that the pin is retained by cooperation with inner surfaces of the blind rail. Blind rails generally have a rectangular "C" shape in cross-section, that is, a rectangle with one face partially removed. In order to retain the cord guide in place in the blind rail, the cord guide of the invention engages with opposed faces of the blind rail, preferably by means of the abovementioned camming action. The pin may be retained in the channel portions by the return walls at the open face of the blind rail. It will be appreciated that in use the cord guide of the invention may lie in any suitable orientation depending, for example on whether the window is vertical, or sloping as is the case for roof windows and conservatories. Further, cord guides in head rails and bottom rails may be oppositely directed and thus the term "upstanding" as used above should be understood with reference to the cord guide itself and not its particular orientation in use. In variations of the invention, the shape of the through bore may be varied as desired, such that the walls of the bore may form a cone, and may include a taper, flare or other desired curvature. An annular projection may be formed at the base of the cord guide around the bore, to engage with a corresponding hole in the blind rail. In addition to assisting in locating the cord guide in its correct location, this projection prevents contact between the cord and the material (usually metal) of the blind rail, which contact would cause wear on the cord. As is known in the art, blind mechanisms may include one or more springs in order to provide a desired tension in the cords used to operate the blind. A particular advantage of the cord guides of the present invention is that the pins may also serve to mount these springs. For example, a coil spring may include loops of wire at its respective ends through which the pin of the cord guide passes. The cord guide and the spring may then be located at any desired position along the blind rail and retained there by engagement of the cord guide with the blind rail. In this way, movement of the springs over time with respect to the blind rail is much reduced or prevented. The cord guides may be used for this purpose whether or not also having a cord passing therethrough. According to third and fourth aspects of the invention there is provided a blind (in particular a pleated blind) including one or more of the cord guides of the first and second aspects respectively of the invention. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made to the following drawings, in which: Figure 1 is a partially exploded, partially cutaway view of a cord guide of the invention located in a blind rail; Figure 2 illustrates a tool for locating the cord guide of the invention in its use position; Figure 3 illustrates a blind mechanism including cord guides and end caps according to the invention; Figures 4a and 4b illustrate an end cap according to the invention; and Figures 5a and 5b illustrate a bracket for anchoring cords or support wires. Referring now to Figure 1, a cord guide 1 is located within a blind rail 2. A cord 3 passes through a bore 4 defined in the cord guide 1, and around a pin 5 which is located in channels 6a and 6b of the cord guide 1. The blind rail 2 has a rectangular "C" shaped cross section with rear wall 13, opposing walls 7a and 7b and return walls 8a and 8b. The cord guide 1 is retained within the blind rail 2 by engagement with the walls 7a and 7b. In particular, the cord guide 1 includes camming surfaces 9, 10 (and corresponding surfaces at the other end of the cord guide, not shown) which allow the cord guide 1 to frictionally engage the blind rail 2. In use, surfaces 10 lie parallel to the inner surfaces of walls 7a, 7b of the guide rail, and the cord guide 1 is so sized that in use the surfaces 10 frictionally engage the inner surfaces of the walls 7a, 7b. In use, the cord guide 1 is inserted into the blind rail 2 with its major axis generally parallel to that of the blind rail 2, that is, in an orientation about 90° anticlockwise (counter-clockwise) from that illustrated in Figure 1. The cord guide 1 is then rotated clockwise so that camming surfaces 9 engage the respective walls 7a and 7b. As rotation continues, the cord guide 1 "snaps" into a position in which the surfaces 10 engage the respective walls 7a and 7b, and from which the cord guide 1 cannot be further rotated in a clockwise direction. The cord guide is then in its use position illustrated in Figure 1. It will be appreciated that by suitable arrangement of the camming surfaces 9, 10, the cord guide 1 may alternatively be "snapped" into its engaged postion by anticlockwise rotation, or by either clockwise or anti-clockwise rotation. The pin 5 which is retained in the channels 6a and 6b is preferably made from metal, in particular from hardened steel, such as a stainless steel. Before insertion of the cord guide 1 into the blind rail 2, the pin 5 is preferably held loosely in channels 6a, 6b. On rotation of the cord guide 1 as described above, the ends of the pin 5 pass beneath the return walls 8a and 8b. The cord guide 1 is so sized that its upper surfaces 11a, lib contact the undersides of the return walls 8a and 8b of the blind rail 2, and the depth of the channels 6a and 6b is such that the pin 5 is restrained from movement in use by the undersides of the return walls 8a and 8b. The cord guide 1 may be located in its use position very simply by means of a tool 21 as illustrated in Figure 2. Tool 21 comprises a body portion 22 which may be cylindrical or any other suitable shape and may be hollow (tubular) or solid. The body portion 22 is preferably tubular. At an end of the body portion 22 are diametrically opposed keyways 23. In use, the keyways are engaged with the upstanding parts (engagement surfaces) 12 of the cord guide 1 which define the channels 6a, 6b and then rotated clockwise (or anti-clockwise, as the case may be) thereby to rotate the cord guide 1. The cord guide 1 may be released, for example for adjustment of the position, by using the tool 21 in a similar manner and rotating in the reverse direction. The tool 21 is particularly advantageous where it is desired to mount springs, such as cord tensioning springs, on the pin of the cord guide. Thus, in manufacture, the pin may be inserted into the ring provided at the end of the spring, with the spring passing into the body of the tool. The tool (and pin) are located on the cord guide and the tool is used to rotate the cord guide as described above. Figure 3 illustrates schematically component parts of a pleated blind including a number of cord guides 1 according to the invention. The blind 31 includes a head rail 32 and a bottom rail 33 and cords 2 together with end caps 34, spring 35 and a shade 36 (only a part of which is shown). This diagram illustrates the potential complexity of the blind mechanism and emphasises the need for smooth operation of the mechanism, without jamming or sticking of the cords 2. It can also be seen that the tension spring 35 may be retained in its use position by the pin 2 of the cord guide 1 ' . In a fifth aspect of the invention there is provided an improved end cap for a blind rail. The end cap of this aspect of the invention comprises a cover surface adapted to cover the end of the blind rail, a pair of arms extending perpendicularly with respect to the inner side of the cover surface, engagement means to engage an inner surface of the blind rail and at least one through bore for receiving a cord. The end cap of this aspect of the invention preferably further comprises channel means for receiving a pin, preferably a metal pin, against which the cord may move. The invention further includes an end cap as defined above including a pin received in the channel means. The engagement means for engaging an inner surface of the blind rail may be formed by the perpendicular arms which provide a friction fit with opposed inner surfaces of the blind rail. Alternatively or additionally, latching means may be provided to engage the blind rail. The latching means may take the form of a projection which is desirably formed on a cross-member linking the perpendicular arms and which projection enters a hole formed in the blind rail. The projection is preferably urged into the hole by the resilient nature of the material from which the end cap is formed. Figures 4a and 4b illustrate an end cap according to this aspect of the invention. Figure 4b shows the cap rotated through 180° with respect to Figure 4a. As shown in Figures 4a and 4b, end cap 34 has a cover surface 41 and depending arms 42a, 42b extending from the inner side of the cover surface 41. The outer surfaces of the arms 42a, 42b may provide a frictional fit against inner surfaces of walls 7a, 7b and/or 8a, 8b and 13 (Figure 1) of the blind rail, in order to retain the end cap in position. Alternatively or additionally, latching means may be provided to retain the cap in its use position. In the embodiment illustrated, the latching means comprises a projection 43 (Fig 4b) which is tapered so that it becomes less prominent in the direction away from the cover surface 41. In use, as the end cap 34 is fitted into the end of a blind rail, the projection 43 slides along the inner surface of the blind rail until the end cap 34 reaches its use position. At this point the projection 43 enters a suitably placed hole in the blind rail so that withdrawal of the end cap 34 is prevented. When it is necessary to remove the end cap, for example for maintenance of the blind, the member carrying the projection 43 may easily be deflected so that the projection 43 passes out of the hole and allowing the end cap 34 to slide outwardly. The end cap 34 may further comprise one or more cross- members 44 to which the end of a cord or a spring may suitably be secured as desired. Further, the end cap 34 includes at least one through bore 45 (Fig. 4a) through which a cord may pass and channel means 46 for receiving a pin 5 (not illustrated). Where a pin 5 is required it may be retained in the channel means 46 in similar manner to the cord guide. That is, the pin 5 may be moulded integrally with the end cap 34 or may be a "snap-fit" when pressed into the channel means 46. Most preferably, the pin 5 is retained in the channel means 46 by the return walls 8a, 8b or the wall 13 of the blind rail (Figure 1). A sixth aspect of the present invention comprises a blind incorporating at least one end cap as defined in the fifth aspect of the invention. The end caps according to the invention are particularly advantageous in that they may simply be slid into the end portions of a blind rail and do not require a force-fit, and the latching mechanism for retaining the cap in place allows easy removal of the cap when necessary and also assists in final assembly of the blind because final positioning of the cap can be left until the last moment. Also, tight extrusion and component tolerances are not required during manufacture. When provided, the pin, which is preferably a metal pin such as a pin of hardened (stainless) steel, allows cords to be turned around corners reliably because of the low friction and wear between the cord and the pin. Furthermore, the pin may be used for securing the ends of cords, support wires or springs used in the blind mechanism. According to a seventh aspect of the invention there is provided a kit for manufacturing a blind comprising at least one blind rail, at least one cord guide according to the first and/or second aspects of the invention and a tool for locating the cord guide in its use position comprising a member, preferably a tubular member having opposed keyways, which keyways are adapted to engage upstanding formations of the cord guide, whereby the cord guide may be rotated to its use position. Preferably, the kit of this aspect of the invention may further comprise at least one end cap as defined in the fifth aspect of the invention. In an eighth aspect of the invention, there is provided a method of manufacturing a blind including the steps of: providing a cord guide according to the first or second aspects of the invention; providing a tool for locating said cord guide in its use position, said tool comprising a member having opposed keyways at an end thereof; inserting said cord guide into a blind rail with its major axis substantially parallel to the major axis of the blind rail; engaging said keyways with upstanding formations of said cord guide and rotating said tool thereby to cause the cord guide to be rotated into its use position. In a further variation of the invention there is provided a bracket for anchoring blind operating cords and/or support wires at a window sill. As may be seen in Figure 5, the bracket 50 comprises an attachment portion 51 which is generally channel shaped with extending wings 52. A hole 53 is provided for attaching the portion 51 to a window sill by suitable means, such as a screw. A cover portion 54 includes flanges 55 which cooperate with the wings 52 to retain the cover portion 54 on the attachment portion 51. The cover portion 54 may simply be slid on to the attachment portion 51 so that the wings 52 engage the flanges 55. The cover portion includes one or more through bores 56 through which cords or support wires may pass, and an optional screw clamp 57 for retaining the cords or support wires. By means of this bracket, the cords or support wires may readily be anchored to the window sill. The bracket is easily removeable, such as for cleaning the window and permits easy adjustment of the cords or wires by means of the screw clamp, such as to adjust a tension spring contained in the blind. Furthermore, the bracket has a particularly slim construction allowing the bottom rail of the blind to be as close as 5mm from the window sill when the blind is closed.

Claims: CLAIMS 1. A cord guide for a blind comprising a main body portion engageable with a blind rail, a through bore for receiving one or more cords, and a pin overlying the through bore and substantially perpendicular to the axis of the bore. 2. A cord guide as claimed in claim 1 wherein the pin is a metal pin. 3. A cord guide as claimed in claim 1 or 2 wherein the pin passes through the axis of the bore. 4. A cord guide as claimed in claim 1, 2 or 3 further comprising oppositely disposed camming surfaces operative to engage, upon rotation of the cord guide, with opposed walls of the blind rail. 5. A cord guide for a blind comprising a main body portion, a through bore to receive one or more cords, oppositely disposed camming surfaces operative to engage, upon rotation of the cord guide, with opposed walls of the blind rail and engagement surfaces by means of which the cord guide may be rotated. 6. A cord guide as claimed in claim 5 further comprising a pin overlying the through bore substantially perpendicular to the axis of the bore. 7. A cord guide as claimed in claim 6 wherein the pin is a metal pin. 8. A cord guide as claimed in claim 6 or 7 wherein the pin passes through the axis of the bore. 9. A cord guide as claimed in any of claims 1 to 4 and 6 to 8 including a channel to receive the pin. 10. A cord guide as claimed in claim 9 comprising upstanding formations diametrically opposed with respect to the through bore and each including a channel portion to receive respective ends of the pin. 11. A cord guide as claimed in any of claims 1 to 4 and 6 to 10 wherein the pin is retained in the cord guide in use by walls of the blind rail. 12. A blind including at least one cord guide according to any of claims 1 to 11. 13. A blind as claimed in claim 12 including at least one cord tensioning spring, which spring is attached to a pin of a cord guide as claimed in any of claims 1 to 4 and 6 to 11. 14. An end cap for a blind rail comprising a cover surface adapted to cover the end of the blind rail, a pair of arms extending perpendicularly with respect to an inner side of the cover surface, engagement means to engage an inner surface of the blind rail and at least one through bore for receiving a cord . 15. An end cap as claimed in claim 14 further comprising channel means for receiving a pin against which a cord may move. 16. An end cap as claimed in claim 15 including a pin received in the channel means. 17. An end cap as claimed in claim 16 wherein the pin is of metal. 18. An end cap as claimed in any of claims 14 to 17 wherein the pair of arms forms the engagement means. 19. An end cap as claimed in claim 18 wherein the arms have a friction fit with inner surfaces of the blind rail. 20. An end cap as claimed in any of claims 14 to 19 wherein the engagement means comprise a latching means. 21. An end cap as claimed in any of claims 14 to 20 further comprising at least one cross-member suitable for attachment of a cord, support wire or spring. 22. A blind including at least one end cap as claimed in any of claims 14 to 21. 23. A blind including at least one end cap as claimed in claims 16 or 17 and at least one cord tensioning spring attached to a pin of said end cap. 24. A kit for manufacturing a blind comprising at least one blind rail, at least one cord guide according to any of claims 1 to 11 and a tool for locating the cord guide in its use position, said tool comprising a tubular member having opposed keyways, which keyways are adapted to engage upstanding formations of the cord guide, whereby the cord guide may be rotated into its use position. 25. A kit as claimed in claim 24 further comprising an end cap as claimed in any of claims 14 to 21. 26. A cord guide for a blind substantially as hereinbefore described with reference to Figure 1. 27. An end cap for a blind rail substantially as hereinbefore described with reference to Figures 4a and 4b. 28. A method of manufacturing a blind including the steps of providing a cord guide according to any of claims 1 to 11, providing a tool for locating said cord guide in its use position said tool comprising a member having opposed keyways, inserting said cord guide into a blind rail with its major axis substantially parallel to the major axis of the blind rail, engaging said keyways with upstanding formations of said cord guide and rotating said tool thereby to cause the cord guide to be rotated into its use position.

Inventors: WOOTTON MALCOLM, WOOTTON, MALCOLM
Applicants: ECLIPSE BLINDS LTD, WOOTTON MALCOLM, ECLIPSE BLIND SYSTEMS LIMITED, WOOTTON, MALCOLM
Application year: 1999
Main classification: E06B9
IPC codes: E06B9