GB2313141A

GB2313141A - End cap for a vertical blind housing

Info

Publication number: GB2313141A
Application number: GB9610301A
Authority: GB
Inventors: Malcolm James Wootton
Original assignee: Eclipse Blinds Ltd
Current assignee: Eclipse Blinds Ltd
Priority date: 1996-05-16
Filing date: 1996-05-16
Publication date: 1997-11-19
Anticipated expiration: 2016-05-16
Also published as: GB2313141B; AU2905297A; WO1997043513A1; GB9610301D0

Abstract

A track assembly for a vertical blind has a idle-end end cap 44 attached to one end of a track housing 30 and includes a cylindrical bearing sleeve 48 that receives one end of a tilt shaft 32. An active-end end cap 10 is attached to the other end of the track housing 30 and includes a rotatable sleeve 28 having a blind bore which engages the other end of the tilt shaft 32. The sleeve is part of a planetary gear carrier 36 and the sun gear is integrally formed with a chain drive chainwheel 12. Each end of the tilt shaft rests in a blind recess, and the tilt shaft is therefore "floating" and need not be placed under stress and the assembly process is greatly simplified. Installation of the chain is greatly simplified if a guide 22 is provided around the periphery of the chainwheel 12. Active-end end cap 10 also includes a pair of cord guides to move the blind slats along the track.

Description

VERTICAL BLINDS Vertical blinds commonly consist of a track, which is installed across the top of a window, and a plurality of travellers which are arranged to run along the track. From each of the travellers, a louvre is suspended, usually from a hook provided for that purpose, and the hook is able to rotate with respect to the remainder of the traveller about a vertical axis. In that way, the louvres may rotate from a closed orientation in which they lie approximately parallel to the track, through a number of different orientations including a fully open orientation in which they lie perpendicular to the track, to another closed orientation at the other limit of their movement. To ensure that all the hooks and therefore the louvres rotate in unison, each hook is coupled within the traveller by worm and spur gears to a rotatable sleeve, the axis of rotation of which lies parallel to the track. The sleeve includes a profiled bore and a correspondingly profiled "tilt shaft" passes through the bore of each of the sleeves. Rotation of the tilt shaft causes the sleeves and hence the hooks to rotate in unison.

In a conventionally constructed vertical blind, the track is defined by an extruded track housing, e.g. of aluminium.

At each end of the housing is an end cap through which the tilt shaft passes and an end cover which when installed over the end cap hides the end of the tilt shaft from view and provides an aesthetic finish. The whole assembly is held together by star-lock washers (a type of circlip which has no break in its perimeter) installed on the tilt shaft after it has been passed through the end caps, thus detaining each end cap between the end of the track housing and the star-lock washer. One end cap is adapted to include a gearbox for transferring drive from a chain, via a chainwheel and a planetary gearbox, to the tilt shaft.

Thus, that end cap includes a well through which the tilt shaft projects, at the bottom of which the star-lock washer is installed. Once the star-lock washer is in place, a planetary gear carrier is installed in the well. The gear carrier includes a profiled bore which engages the end of the tilt shaft, and two or more planetary gears which engage with teeth formed around the periphery of the well.

The sun gear, attached to the chainwheel, is then inserted into the centre of the planetary gear carrier, the chain placed around the chainwheel and the end cover fixed in place, e.g. by screws.

This assembly procedure is time-consuming and requires a degree of dexterity in the assembly line operator in the installation of the star-lock washers and in the assembly of the planetary gearbox and chain drive. In addition, since the tilt shaft holds the end caps in place on the track housing, to avoid play in the end caps, the tilt shaft is placed under a degree of tension. The tilt shaft is therefore more difficult to turn than it would be if free from tension, due to the parasitic effect of friction at the star-lock washers. This does not make for smooth operation and is wasteful of energy in a powered system.

The present invention provides a track assembly for a vertical blind comprising a track housing, a tilt shaft, an idle-end end cap adapted to be attached to one end of the track housing and including a blind bearing housing adapted to receive one end of the tilt shaft and an active-end end cap adapted to be attached to the other end of the track housing and including a rotatable output sleeve having a blind bore adapted to engage the other end of the tilt shaft and means for rotating the output sleeve so as to rotate the tilt shaft in the bearing housing.

There are many advantages to an assembly in accordance with the present invention as follows. Firstly, it will be understood that as the end caps are attached to the track housing, the requirement for the tilt shaft to hold the assembly together is obviated. Secondly, each end of the tilt shaft rests in a blind recess, either in the bearing housing or the output sleeve, and the tilt shaft is therefore "floating and need not be placed under stress.

Indeed, it is preferred that there be a slight degree of longitudinal play in the mounting of the shaft in the end caps. Thirdly, as the tilt shaft is itself retained in place by the blind recesses in the end caps, no star-lock washers are required and the assembly process is greatly simplified. For example, first the idle-end end cap is attached to the track housing, next the tilt shaft is installed in the blind bearing housing and lastly the active-end end cap is attached to the other end of the track housing, ensuring that the free end of the tilt shaft is properly in place in the output sleeve. Alternatively, the active-end end cap may be the first to be installed, followed by the tilt shaft and the idle-end end cap. The travellers may be installed before, after or together with the tilt shaft. This is a significant simplification and leads to further possibilities of simplification as follows.

In a conventional blind as described above, because a starlock washer has to be installed at the bottom of the well in the active-end end cap, the planetary gearbox must be assembled after the tilt shaft is installed. However, in the present invention, this constraint no longer applies.

On the contrary, the gearbox in the active-end end cap may be fully assembled before the end cap is installed on the track housing. One problem inherent in gearbox assembly, whenever performed, is that of installing the drive chain on the chainwheel. In the conventional blind, as described, the chain is simply wrapped around the chainwheel before an end cover is installed. This could be done with the active-end end cap of the present invention, but this chain installation method is unsatisfactory as it requires four pieces of the assembly to be manipulated at once: the chain, the chainwheel, the end cap and the end cover. The present invention provides a much more elegant solution to this problem.

To solve this problem, it is preferred that the end of the output sleeve in which the blind bore is provided should project from the active-end end cap, the means for rotating the output sleeve should include a chainwheel adapted to mesh with a drive chain and coupled to the output sleeve and a guide should surround at least part of the chainwheel for retaining the chain in mesh with the chainwheel. This arrangement is a significant improvement on the conventional assembly as follows. The output sleeve projects from the active-end end cap and is only able to do so because a floating tilt shaft arrangement is being used in which there is no requirement for star-lock washers; otherwise the washer retaining the tilt shaft in the active-end end cap would prevent the output sleeve from so projecting. Thus, the projecting output sleeve can be grasped and rotated, thereby rotating the chainwheel. The advantage of this is the chain may be introduced into one side of the chainwheel, the output sleeve rotated to rotate the chainwheel and hence drag the chain around the chainwheel, with which it is retained in mesh by the guide, to emerge on the other side of the wheel, fully installed.

This aspect of the present invention may exist independently of the track assembly as described above and, accordingly, the present invention also extends to an active-end end cap, adapted to be attached to one end of a vertical blind track housing, including a rotatable output sleeve, one end of which projects from the end cap and has a blind bore adapted to engage one end of a tilt shaft, a chainwheel adapted to mesh with a drive chain and coupled to the output sleeve and a guide surrounding at least part of the chainwheel for retaining the chain in mesh with the chainwheel.

To provide the conventional gearing ratios, it is preferred that the active-end end cap includes a well through which the output sleeve projects, the output sleeve is an integral part of a planetary gear carrier which includes two or more planetary gears that mesh with teeth formed around the periphery of the well, a sun gear attached to the chainwheel, inserted into the centre of the planetary gear carrier and meshing with the planetary gears, and an end cover retaining the chainwheel and sun gear in situ.

Because the drive chain conventionally hangs down vertically from both sides of the chainwheel, it is preferred that the guide is substantially semi-circular in extent. The active end of the track needs to accommodate a cord which controls the traverse function of the travellers. Thus, it is preferred that the end cap further includes a pair of cord guides for an outward and return length of traverse control cord. Conventionally, each length of cord hangs vertically from the end cap, turns through 90 degrees and proceeds along the track housing.

Thus, it is preferred that the cord guides be substantially quarter-circular in extent. Although the cord guides could be formed as progressive right-angle bends in a cordreceiving conduit, the preferred arrangement is that each cord guide should surround a part of the periphery of a pulley.

The end cap or at least one end cap may include a projection in which a nut is held captive and a bolt adapted to thread through the nut and tighten onto the track housing. The bearing housing may comprise a substantially cylindrical sleeve integral with the idle-end end cap.

For assembly into a fully working vertical blind, the assembly will further comprise a plurality of travellers, each having a profiled rotatable sleeve having a bore for passage of the tilt shaft, the tilt shaft and bore being correspondingly profiled such that rotation of the tilt shaft causes rotation of the sleeve, and a louvresuspending element coupled to the sleeve such that rotation of the sleeve causes rotation of the louvre-suspending element. When assembled, the blind must be such that one traveller is retained motionless (although still able to rotate) at one end of the track. According to the invention, this is achieved in an assembly in which the track housing comprises an elongate slot to accommodate the louvre-suspending elements of the travellers, by providing an end spacer adapted to engage and slide within the slot and including an opening to accommodate the louvresuspending element of the endmost traveller and a releasable latch formed on the end spacer and the activeend or idle-end end cap for retaining the end spacer at the end of the track housing. This arrangement has two advantages. Firstly, the end spacer hides a part of the slot in the track housing, improving the aesthetics of the assembled product. Secondly, because the latch is releasable, all the travellers can be moved to the opposite end of the track for cleaning purposes.

Again, this is an aspect of the present invention which can exist independently of the particular assembly described.

Thus, the present invention also extends to a track assembly for a vertical blind comprising a track housing comprising an elongate slot to accommodate a louvresuspending element of a traveller, an end spacer adapted to engage and slide within the slot and including an opening to accommodate a louvre-suspending element of an endmost traveller, an end cap adapted to be attached to one end of the track housing and a releasable latch formed on the end spacer and the end cap for retaining the end spacer at the end of the track housing.

The latch may include a deformable tongue on the end cap and a detent on the end spacer adapted to engage the deformable tongue.

The present invention will now be described by way of example with reference to the accompanying drawings in which: FIG. 1 is a partly cut-away end view of an active-end end cap; FIG. 2 is a section of the active-end end cap showing the tilt shaft, gearbox and chain drive; FIG. 3 is another section of the active-end end cap showing a cord pulley and guide; FIG. 4 is a section through the idle-end end cap showing the tilt shaft; FIG. 5 is another section through the idle-end end cap showing the captive nut and bolt; and FIG. 6 is a further section through the idle-end end cap showing the end spacer.

Briefly, the active-end end cap 10 shown in FIG. 1 can be seen to include a chainwheel 12, which takes drive from a continuous chain 14, and a pair of cord pulleys 16, around each of which is wrapped a length of traverse control cord 18. Integral with the body 20 of the end cap 10 is a semicircular guide 22, the purpose of which will become apparent. An end cover 24 (shown partly cut away) encloses the end cap mechanisms.

FIG. 2 shows in section the active-end end cap 10, the track housing 30, the tilt shaft 32, gearbox and chain drive. As can be seen the tilt shaft 32 is received within a profiled blind bore 40 of a projecting sleeve 28, which is an integral part of a planetary gear carrier 36. The outer surface of the sleeve 28 is knurled (illustrated at 34) as a gripping aid. The planetary gear carrier 36 includes four planetary gears 26 which mesh with teeth (not shown) provided around the inner periphery of a well 38 formed in the body 20 of the end cap 10. A sun gear (not shown) is attached to the chainwheel 12 and is inserted into the planetary gear carrier 36, where it meshes with the planetary gears 26. This, it will be appreciated that rotation of the chainwheel 12 by the chain 14 results in rotation of the tilt shaft 32 after the planetary gear reduction and vice versa.

The chain 14 may be simply installed on the chainwheel 12 as follows. The projecting sleeve 28 is grasped and rotated, thereby rotating the chainwheel 12. One end of the chain 14 is introduced into the nip formed between one side of the chainwheel 12 and the guide 22. Rotation of the sleeve 28 rotates the chainwheel 12 and drags the chain 14 around the chainwheel 12, with which it is retained in mesh by the guide 22, to emerge on the other side of the chainwheel 12, fully installed. The end cap 10 may then be attached to the track housing 30 in any suitable way.

FIG. 3 is shows the active-end end cap, the cord pulley and cord guide. As can be seen, a quarter-circular guide 42 surrounds a part of the surface of the cord pulley 16. The need for this arises because it is preferable to assemble the entire active-end end cap before the chain or cords are installed, thus making for easy assembly. The guides 42 are required to guide the cord 18 around the pulleys 16 to allow the cord 18 to be installed simply by poking it through the gap between the guide 42 and the pulley 16.

The guide 42 is so shaped as to allow the cord 18 to be installed from either direction.

FIG. 4 shows the idle-end end cap and the tilt shaft. As can be seen, the end of the tilt shaft 32 simply rests in a cylindrical sleeve 48 formed on the end cap 44, the sleeve 48 acting as a bearing housing. An end traveller 46 is also shown, but will be discussed further below. As is common, the traveller 46 includes a profiled rotatable sleeve (not shown) having a profiled bore for passage of the tilt shaft 32 and a hook 64 coupled to the sleeve such that rotation of the sleeve causes rotation of the hook 64.

FIG. 5 shows the attachment of the idle-end end cap using a captive nut and bolt. The end cap 44 includes a projection 54, in which is held captive a nut 52. A bolt 50 is threaded into the nut 52 and tightened down into abutment with the track housing 30. A similar arrangement may be provided on the active-end end cap 10. Of course, it will be appreciated that the nut and bolt arrangement could be replaced by a self-tapping screw or indeed any other suitable fixing means.

FIG. 6 shows the idle-end end cap and the end spacer. The end spacer 56 includes a pair of L-shaped sliders sliders 62 on each side which engage the edges of the slot formed in the track housing 30. A circular hole 66 is formed in the end spacer 56, through which the hook 64 on the end traveller 46 projects. A deformable tongue 58 on the projection 54 of the end cap 44 engages a corresponding detent 60 on the end spacer 56, forming a latch. The latch is releasable to permit the end spacer 56 and traveller 46 to be moved (to the left in the drawing) for cleaning purposes. The lower surface 68 of the end spacer 56 is profiled for aesthetic reasons.

Claims

CLAIMS:

1. A track assembly for a vertical blind comprising a track housing, a tilt shaft, an idle-end end cap adapted to be attached to one end of the track housing and including a blind bearing housing adapted to receive one end of the tilt shaft and an active-end end cap adapted to be attached to the other end of the track housing and including a rotatable output sleeve having a blind bore adapted to engage the other end of the tilt shaft and means for rotating the output sleeve so as to rotate the tilt shaft in the bearing housing.

2. A track assembly according to claim 1 in which the end of the output sleeve in which the blind bore is provided projects from the active-end end cap, the means for rotating the output sleeve includes a chainwheel adapted to mesh with a drive chain and coupled to the output sleeve and a guide surrounds at least part of the chainwheel for retaining the chain in mesh with the chainwheel.

3. An active-end end cap, adapted to be attached to one end of a vertical blind track housing, including a rotatable output sleeve, one end of which projects from the end cap and has a blind bore adapted to engage one end of a tilt shaft, a chainwheel adapted to mesh with a drive chain and coupled to the output sleeve and a guide surrounding at least part of the chainwheel for retaining the chain in mesh with the chainwheel.

4. An assembly or end cap according to any one of claims 1-3 in which the active-end end cap includes a well through which the output sleeve projects, the output sleeve is an integral part of a planetary gear carrier which includes two or more planetary gears that mesh with teeth formed around the periphery of the well, a sun gear attached to the chainwheel, inserted into the centre of the planetary gear carrier and meshing with the planetary gears, and an end cover retaining the chainwheel and sun gear in situ.

5. An assembly or end cap according to claim 4 in which the said guide is substantially semi-circular in extent.

6. An assembly or end cap according to any preceding claim in which the active-end end cap further includes a pair of cord guides for an outward and return length of traverse control cord.

7. An assembly or end cap according to claim 6 in which the cord guides are substantially quarter-circular in extent.

8. An assembly according to claim 6 or claim 7 in which each cord guide surrounds a part of the periphery of a pulley.

9. An assembly or end cap according to any preceding claim in which the end cap or at least one end cap includes a projection in which a nut is held captive and a bolt adapted to thread through the nut and tighten onto the track housing.

10. A track assembly according to any one of claims 1, 2 and 4-9 in which the bearing housing comprises a substantially cylindrical sleeve integral with the idle-end end cap.

11. A track assembly according to any one of claims 1, 2 and 4-10, further comprising a plurality of travellers, each having a profiled rotatable sleeve having a bore for passage of the tilt shaft, the tilt shaft and bore being correspondingly profiled such that rotation of the tilt shaft causes rotation of the sleeve, and a louvresuspending element coupled to the sleeve such that rotation of the sleeve causes rotation of the louvre-suspending element.

12. A track assembly according to claim 11 in which the track housing comprises an elongate slot to accommodate the louvre-suspending elements of the travellers, an end spacer adapted to engage and slide within the slot and including an opening to accommodate the louvre-suspending element of the endmost traveller and a releasable latch formed on the end spacer and the active-end or idle-end end cap for retaining the end spacer at the end of the track housing.

13. A track assembly for a vertical blind comprising a track housing comprising an elongate slot to accommodate a louvre-suspending element of a traveller, an end spacer adapted to engage and slide within the slot and including an opening to accommodate a louvre-suspending element of an endmost traveller, an end cap adapted to be attached to one end of the track housing and a releasable latch formed on the end spacer and the end cap for retaining the end spacer at the end of the track housing.

14. A track assembly according to claim 12 or claim 13 in which the latch includes a deformable tongue on the end cap.

15. A track assembly according to claim 14 in which the latch further includes a detent on the end spacer and adapted to engage the deformable tongue.

16. A track assembly for a vertical blind substantially as described herein with reference to the accompanying drawings.

17. An active-end end cap, adapted to be attached to one end of a vertical blind track housing, substantially as described herein with reference to the accompanying drawings.