WO2005028801A1

WO2005028801A1 - A winding mechanism

Info

Publication number: WO2005028801A1
Application number: PCT/DK2004/000623
Authority: WO
Inventors: Poul Christian Jensen
Original assignee: Faber A/S
Priority date: 2003-09-19
Filing date: 2004-09-17
Publication date: 2005-03-31

Abstract

The invention relates to a winding mechanism (1) for winding a cord (2) for a folding blind onto an elongate rotatable winding drum (15) having a first end to which the one end of the cord (2) is secured and a second end. The drum (15) has a first portion (16) with a diameter which is smaller than the diameter of a second portion (17) of the drum (15). The winding mechanism (1) has an introduction portion (6) which protrudes radially in relation to the drum (15) and which defines, at the second portion of the drum (15), an area of introduction, where the cord (2) is conveyed into the mechanism (1). According to the invention the mechanism (1) has a protrusion (23) which is fixed in relation to the drum (15) and extends in a direction along the drum (15) across a part of the periphery of the drum (15) to establish a receiving area (19) on the drum (15) for a site (2') on the cord (2) which has, by turning of the drum (15), just been introduced into the mechanism (1). Protrusion (23) defines an abutment means (24) oriented transversally to the longitudinal direction of the drum (15) and intended for cord (2') already wound onto the drum (15), whereby said site (2') on the cord (2) is, while the cord (2) is being wound by rotation of the drum (15), conveyed past said abutment means (24) in abutment thereon and in a direction towards the first end of the drum (15).

Description

A winding mechanism

The present invention relates to a winding mechanism for winding a cord for a folding blind onto an elongate rotatable winding drum having a first end to which the one end of the cord is attached and a second end, said drum having a first portion at said first end with a diameter which is smaller than the diameter of a second portion of the drum at the second end, said winding mechanism having an introduction portion protruding radially in relation to the drum and which defines, at the second portion of the drum, an introduction area where the cord is introduced into the mechanism. Such winding mechanism is known from EP 554212.

Usually, folding blinds comprise a number of strings extending in parallel and extending from the top edge of the curtain to its lower end. Each of these strings extends through loops secured to the curtain fabric, and when the cord is wound around the drum to the effect that the lower edge is drawn towards the upper edge, the curtain will fold while forming pleats. In particular in case of very long folding blinds, where the distance between the top edge of the curtain and its lower edge is large, a relatively long cord length is required, which in turn means that the drum has to be configured to be relatively long to accommodate the fully wound length of cord. In particular cases the long length of the drum will mean that the distance between the parallel strings of the curtain has to be so large that it is not possible to establish an even pull in the lower edge of the curtain.

In connection with the prior art mechanism it has been attempted to solve the above-reference problem by using a thinner cord thereby reducing the length of the drum. However, it has been found that the known mechanism used in combination with very thin strings causes the cord to be wound on top of itself and thus it does not form an even helical winding on the drum. The invention aims to address that problem in that, at the second portion of the drum, the mechanism has a protrusion which is fixed in relation to the drum and extends in a direction along the drum across a portion of the periphery of the drum in order to establish a receiving area on the drum for a site on the cord that will, when the drum is turned, just be introduced into the mechanism, said protrusion also defining an abutment means oriented perpendicularly to the longitudinal extension of the drum and intended for cord that is already wound around the drum, whereby said site on the cord is, during winding of the cord by turning of the drum, conveyed past said abutment means in abutment thereon and in a direction towards the first end of the drum.

It has thus been found to be possible to achieve a uniform winding of thin strings.

The cord, ie each of the parallel strings of the folding blind, carrying the folding blind is, in accordance with the invention, preferably attached releasably to the drum, whereby the entire folding blind can be removed from the winding mechanism which is typically fixedly secured on eg the top edge of a window frame. To this end the drum can be formed of a hollow pipe with a pipe wall that has a smooth surface, a part of the tube wall being, at the first end of the drum, secured releasably to the remaining part of the drum. The one end of the cord is connected to said part of the tube wall.

The fact that said protruding portion comprises a passage with a contact face for the cord and an opening by which the cord can be released from the passage enables simple dismounting of the folding blind from the winding mechanism. Preferably the drum is journalled interiorly of a housing that comprises a part of a Velcro-connection for the folding blind. In the following, the invention will be explained in further detail with reference to the drawing.

Figure 1 shows a winding mechanism for a cord that is a constituent of a folding blind;

Figure 2 shows the mechanism of Figure 1 with a part of the structure cut away for the sake of clarity;

Figure 3 shows a variety of the mechanism shown in Figure 1 ; and

Figure 4 shows the mechanism of Figure 3, seen in an end view.

In Figure 1 , reference numeral 1 generally designates a winding mechanism for a cord 2 that is a constituent of a not shown folding blind. For instance, the folding blind may be of the type shown in DE 197 28 739 by reference numeral 12, and winding of the cord causes the folding blind to be folded in that the lower edge of the folding blind is lifted upwards.

The winding mechanism according to the invention is particularly suitable for use in connection with folding blinds of the type that is releasably secured, eg by means of a Velcro-connection as also shown in said German patent. The fact that they are releasable makes it possible to wash the curtain and presupposes in general that cord partaking in the folding blind structure can be released from the winding mechanism. This can be accomplished eg in accordance with the principles that were also demonstrated in the German patent disclosure, ie by use of a clip that is secured at the end of the cord and can be secured in a releasable manner to the winding drum of the winding mechanism, shown in Figure 1 by reference numeral 15. In Figure 1 the winding mechanism 1 is shown in further detail, and the winding mechanism 1 more specifically comprises an elongate housing 5 intended for being immovably mounted interiorly of a not shown suspension rail that is secured at the top of a window frame or elsewhere where the folding blind is to be arranged. The housing 5 and the winding drum 15 are preferably made of plastics.

At each end the housing 5 comprises bearings 10 and 11 , respectively, for the winding drum 15, and the winding drum 15 is intended for being rotated by an operating rod 25 that can be connected to an activator cord of the kind shown by reference numeral 16 in the above-referenced German patent disclosure. On a radially protruding introduction portion 6 most proximate the bearing 11 , the housing 5 has a contact face 7 for the cord 2. This contact face 7 ensures that, at any time, the cord 2 travels into the housing 1 in the correct area of the winding drum 15. The protruding introduction portion 6 thus defines an area of introduction for the cord 2 and, besides, it is configured with a slot-shaped aperture 8 that communicates with the contact face 7. The opening 8 has a width that corresponds at least to the thickness of the cord 2.

At its one end, most proximate the bearing 10, ie opposite the outwardly protruding introduction portion 6, the winding drum 15 is configured with a mounting site 20 for a clip 3 that is secured to the end of the cord 2 by means of a not shown knot. In Figure 1 , a portion of the cord 2 is wound around the winding drum 15, corresponding to an onsetting folding of the folding blind. It will be understood that, following unwinding of the entire cord 2 from the drum 15 and simultaneous release of the clip 3 from the mounting site 20, it will be possible to release the cord 2 from the winding drum 15. Subsequent conveyance of the cord 2 through the opening 8 makes it possible to release the clip 3 that has a somewhat larger dimension than the cord 2 from the winding mechanism 1 as such, following which the folding blind comprising the cord 2 can be removed entirely from the winding mechanism 1.

More specifically the winding drum 15 is of the kind shown in Figure 7 of EP 554 212, the drum 15 having a cylindrical portion 16 that extends in a direction from the bearing 10 and continues into a conical portion 17 whose diameter expands in a direction towards the bearing 11 , and continues into a cylindrical portion 17 having a diameter that exceeds the diameter of the cylindrical portion 16. Most proximate the bearing 11 , the housing 5 has an annularly extending shoulder 22 with a larger diameter than the cylindrical portion 17 and adjoining the cylindrical portion 17 for forming an annular protrusion that extends around the drum 15. The cylindrical portion 17 having the largest diameter is more specifically arranged at the area of introduction of the cord 2, ie behind the protruding introduction portion 6. This will appear most clearly from Figure 3, where it is also shown that the winding mechanism 1 according to the invention on has a protrusion 23 arranged on the annular shoulder 22. The protrusion 23 extends from the annular shoulder 22, across the cylindrical portion 17. Preferably, the extension of the protrusion 23 from the shoulder 22 towards the cylindrical portion 16 corresponds at least to the thickness of the cord 2. The distance of the protrusion 23 above the cylindrical portion 17 is somewhat smaller than the thickness of the cord 2, thereby preventing the cord 2 from wedging itself between the protrusion 23 and the drum 15, when the drum rotates relative to the protrusion 23.

In Figures 3 and 4, the protruding introduction portion 6 has a slightly different configuration than that of the protruding introduction portion 6 shown in figures 1 and 2; however, apart from that, the winding mechanism 1 is configured in the same manner. It is noted that the configuration of the drum 15 is selected on the basis of the same principles that were described in EP 554 212, the gradual reduction of the drum 15 diameter in a direction towards the bearing 10 bringing about a complete relief of the pull in that part of the cord that is wound onto the cylindrical portion 16.

In Figure 2, a part of the housing 5 is cut away to show how the cord 2 is wound by turning of the winding drum 15 in relation to the housing 5. It will appear that a part 2' of the cord 2 which has just been introduced into the housing 5 by rotation of the drum 5, sits on the top face of the fixed protrusion 23; and that this part 2' will, by continued turning of the drum 15, abut directly against the surface of the cylindrical portion 17 in a receiving area 19 immediately next to the shoulder 22. Moreover, it will appear that a portion 2" of the cord 2 which was, in a preceding full rotation of the drum 15, introduced into the housing 5 abuts on the fore edge 24 (see Figure 3) of the protrusion 23. It will be understood that the protrusion 23 ensures that the part of the cord 2 that is at any time in the process of being taken into the housing is not wound on top of the cord already wound onto the drum 15. The protrusion 23 ensures that the cord 2 is at all times able to abut directly against the drum 15 in the receiving area 19, the drum 15 being kept clear of cord next to the protrusion 23. The fore edge 24 of the protrusion 23 will, via the portion 2" of the cord 2, press cord that was, in preceding rotations of the drum 15, already wound onto the drum 15 in a direction towards the bearing 10. Owing to the reduced diameter of the cylindrical portion 16 and due to the drum 15 being preferably configured from a material that yields low frictional resistance, such shifting of wound cord could take place without any significant frictional resistance between the wound cord and the drum 15.

In Figure 4 the mechanism 1 of Figure 3 is shown, seen in a direction towards the bearing 11 , and it will appear there from how the cord 2 and hence the entire folding blind can be removed from the winding mechanism 1 by conveyance of the cord 2 through the aperture 8 following release of the clip 3. In Figure 3 the extension of the protrusion 23 in the peripheral direction of the drum 15 is shown to be quite modest, within the range of from 10 to 30° at a drum 15 diameter of about 15-40 mm. However, nothing prevents the extension of the protrusion in the peripheral direction from constituting as much as eg 180° of the circumference of the drum 15.

Claims

C l a i m s

1. A winding mechanism (1 ) for winding of a cord (2) for a folding blind onto an elongate rotatable winding drum (15), which has a first end to which the one end of the cord (2) is attached, and a second end; said drum (15) having a first portion (16) at said first end with a diameter which is smaller than the diameter of a second portion (17) of the drum (15) at the other end, said winding mechanism (1) having an introduction portion (6) which protrudes radially in relation to the drum (15) and which defines, at the second portion (17) of the drum (15), an area of introduction where the cord (2) is introduced into the mechanism (1 ), characterised in that the mechanism (1) at the second portion (17) of the drum (15) has a protrusion (23) which is fixed in relation to the drum (15) and extends in a direction along the drum (15) across a part of the periphery of the drum (15) to establish a receiving area (19) on the drum (15) for a site (2') on the cord (2) which has, by rotation of the drum (15), just been introduced into the mechanism (1 ), said protrusion (23) also defining an abutment means (24) oriented perpendicularly to the longitudinal extension of the drum (15) and intended for cord (2") already wound onto the drum (15), whereby said site (2') on the cord (2) is, during winding of the cord (2) by rotation of the drum (15), taken past said abutment means (24) in abutment there against and in a direction towards the first end of the drum (15).

2. A winding mechanism according to claim 1 , characterised in that the cord (2) is secured in a releasable manner to the drum (15).

3. A winding mechanism according to claim 1 , characterised in that the drum (15) is formed of a hollow tube with a tube wall having a smooth surface; and that a portion (3) of the tube wall is, at the first end of the drum (15), releasably secured to the remainder of the drum (15), the one end of the cord (2) being connected to said part (3) of the tube wall.

4. A winding mechanism according to the preceding claim, characterised in that the protruding introduction portion (6) comprises a passage with a contact face (7) for the cord (2), and an opening (8) via which the cord (2) can be released from the passage.

5. A winding mechanism according to any one of the preceding claims, characterised in that the protrusion (23) extends along the periphery of the drum (15) corresponding to at least about 1.5° of the periphery of the drum (15), preferably corresponding to at least 2°, most preferably at least 10°.

6. A winding mechanism according to the preceding claim, characterised in that the protrusion (23) extends along the periphery of the drum (15) corresponding to a maximum of about 190° of the periphery of the drum (15), preferably corresponding to a maximum of 180°.

7. A winding mechanism according to any one of the preceding claims, characterised in that the drum (15) is joumalled interiorly of a housing (5) that comprises a part of a Velcro-connection for the folding blind.

8. A winding mechanism according to any one of the preceding claims, characterised in that the first portion (16) is cylindrical and extends into a conical portion (18) that continues into the second portion (17) which is cylindrical and has a diameter that exceeds the diameter of the first portion (16); and that the abutment means (24) is arranged in proximity of the transition between the conical portion (18) and the second portion (17).