Patent Grant
8381793
The present invention relates generally to Venetian blinds and more particularly to mechanisms for lifting and tilting of the slats.
The trend in many modern buildings is to use large window panels. The architectural desires lead to façades that require screens against sunlight. Most commonly conventional laminar blinds are used to provide the required shading. The size of the slats of such blinds and the maximum free span between the support cords are, however, limited. Simply scaling up the blinds and slats would lead to various kinds of stability problems. Typically in venetian blinds presently available the slats have dimensions up to about 10-cm width and a free span between the support cords of about one meter. The limited span between the support cords and the consequent high number of support cords combined with a large number of narrow slats may spoil the original aesthetic effect provided by the large glass panels. Another solution has been to limit the size of the glass panels to the dimensions of the available blinds, thus limiting the architectural freedom.
Furthermore large, unbroken window panels may lead to acoustical problems in the room bounded by these panels due to undesirable sound reflections from these panels. It would hence be desirable to have access to venetian blinds with extended length of the slats and corresponding extended span between support cords, which venetian blinds could also, for instance as an option, provide desired acoustical damping of reflections from panels covered by the venetian blinds.
Furthermore, the removal of slats for instance for replacement of these can in many prior art venetian blinds be a cumbersome process, for instance due to the lift cords being passed through passages in the individual slats and the slats being supported by the tilt cords according to the traditional ladder-cord arrangement. Such arrangements make the removal and replacement of individual slats difficult and often even impossible without dismantling major portions of the venetian blind. It would hence be desirable to provide venetian blinds of the above kind shaped and attached to tilt cords in a manner that would facilitate removal of individual slats. Furthermore, the provision of passages in the slats—either in the form of centrally located elongated slits as is often done for passage of the lift cords—or along the edge portions of the slats, for passage of attachment means for the tilt cords through each individual slat, is not optimal from a production point of view or from the point of view of cleaning of the slats. Moreover, it makes it difficult to prevent light from penetrating the slats through these passages and for instance the centrally located passages for the lift cord must necessarily be of a relative large lateral extension if the slats have to be able to undergo tilting over a major portion of the vertical tilt range from one of the slats' substantially vertical position through the horizontal position to the other substantially vertical position of the slats.
Slats for venetian blinds where the tilt cords are attached to the longitudinal edge portions of the individual slats are for instance described in GB 1 512 274 and DE 38 19 920 A1.
Thus, GB 1 512 274 discloses slats for a venetian blind comprising longitudinally extending rounded flanges through which staples are driven and secured. Supporting strings are attached to these staples outside each longitudinal edge portion of the slats. This document furthermore discloses a special tool used to facilitate driving the staples through the flanges.
DE 38 19 920 A1 discloses slats for a venetian blind where the longitudinal edge portions are formed as rounded flanges somewhat similar to those of the above document. At the appropriate locations along the longitudinal direction of the slats these flanges are provided with slots cut through the flanges and some distance into the main portion of the slat. Into these slots are inserted clips formed for pivotally engagement with corresponding spherical members attached to the supporting cords.
On this background, it is the object of the present invention to provide a venetian blind of the kind referred to initially, which overcomes the above-mentioned problems.
It is thus an object of the present invention to provide a venetian blind which can be used to cover large window panels comprising slats of a considerable longitudinal extension and with a large span between the support cords or tilt cords for suspending the slats and where the individual slats can furthermore easily be removed and replaced without having to remove other slats of the venetian blind and without the application of tools.
This object is achieved by providing a venetian blind that allows use of slats with dimensions that were hereto not possible. In order to increase the usable dimensions of the slats of the venetian blind, the overall rigidity of the slats must be sufficiently high, and this is attained according to the invention by providing slats comprising an elongated main portion on either longitudinal side hereof provided with edge portions comprising a first portion and an opposing second portion forming a space there between, where said edge portions are furthermore provided with a gap, through which gap said space is accessible from outside. These edge portions on the one hand increases the overall rigidity of the slats and serves on the other hand as attachment means on the slats for connecting the slats to support cords or tilt cords, as will be described further in the following. The dimensions of said space are larger than the dimensions of the gap, whereby an attachment means connected to the support cords and inserted through said gap will be retained in a releasable manner within the space in the edge portions of the slats as will be described in more detail in the following.
According to an embodiment of the invention the rigidity of the slats is furthermore increased by providing said main portion with an arched cross-sectional shape, but other cross-sectional shapes, including planar slats, are also within the scope of the present invention.
In order to further increase the overall rigidity of the slats the main portion 2 could also be corrugated or even be provided with downwardly extending ribs on the bottom surface of the main portion.
According to the invention attachment means for releasable attachment of the slats to supporting cords are inserted into the edge portions through said gap, said attachment means being also attached to the supporting cords. The releasable attachment means may be resilient in order to make it pass through a gap surrounded by substantially rigid boundaries, but it is also possible according to the invention to surround the gap by resilient boundaries for passage of substantially rigid attachment means through the gap. The attachment means according to the invention is thus formed for insertion through said gap into said space for engagement with at least some of the boundaries of said space. Some embodiments of attachment means for use with the slats according to the invention are shown and described in the detailed description of the invention, but modifications and variations of these embodiments would also be possible without departing from the scope of the invention.
The present venetian blind provides for slats with a width in excess of 200 mm, free spans between the supporting cords of up 2.5 m and more, slats with a length of at least 4 meters and a height of the blind of 6 m and more. It is understood that it is within the scope of the invention to apply more than two pairs of supporting cords if necessary in connection with very long slats, i.e. slats with a length by far exceeding the stated 4 meters.
The slats according to the invention can be made of a number of different materials. Typically the slats are made of a suitable metal, such as aluminium or steel, but other metals can also be used. Also a composite material may be used or the slats can be moulded in fibreglass etc. The prime prerequisite governing the choice of material is the necessary rigidity of the slats, but it is possible to some extend to compensate for reduced rigidity due to the choice of material by proper shaping of the slats.
It is a further object of the present invention to provide a venetian blind, which can be used to influence the acoustical characteristics of the room, in which the venetian blind is used. This object is attained according to the invention by providing at least certain portions of the slats with an acoustic damping arrangement. Thus according to an embodiment of the invention, it is possible between said edge portions of the slats to place a longitudinally extending bottom panel, preferably—although not necessarily—extending along the entire longitudinal dimension of the slat. This panel is preferably substantially planar, but other shapes could also be used, and may even prove desirable under certain circumstances. This panel can serve at least two functions. It may provide the slats with a more attractive appearance as seen from the bottom side of the slats and/or it may be utilised as an acoustic structure to improve the sound dampening characteristics of the slat. For this purpose the panel may be provided with through holes or slits providing access to the region between the panel and the main portion of the slat and this region may be provided with appropriate sound damping material in a manner known per se. Instead of a perforated panel other sound damping structures, such as a suitable fabric may also be used.
In order to obtain an aesthetically satisfactory effect it is important to suspend and operate the slats in a manner that ascertains proper alignment of all slats both in situations where the slats are stationary and during raising, lowering and tilting operations of the slats, as even minor deviations from proper alignment may subtract materially from the overall appearance of the venetian blind. As mentioned above it is furthermore desirable to be able to remove and replace individual slats easily and preferably without the application of tools. These requirement are fulfilled according to the invention by the use of a combined lift and tilt system comprising at least two pairs of tilt cords, each of the tilt cords being attached to the individual slats by means of releasable, preferably resilient clips for insertion into said edge portions of the slats. Running parallel with and preferably in close proximity to at least two pairs of said tilt cords there are provided lift cords, attached at the lower end to the lowermost slat of the venetian blind and at the upper end to a combined lift and tilt mechanism, to which mechanism also the tilt cords are connected. The extension of the lift cords in parallel with the tilt cords may be ascertained by passing the lift cords through loops formed on the tilt cords for instance at the level of each individual slat, but other means of maintaining a parallel arrangement of the lift and tilt cords may also be conceived by a skilled person, without departing from the scope of the present invention.
According to a specific embodiment of the invention, which will be described in more detail in the detailed description of the invention, two pairs of tilt cords are applied running in parallel with and in close proximity to two corresponding pairs of lift cords in the manner outlined above. According to this embodiment the points of attachment of lift- and tilt cords to the slats are located at a distance from either end of the slats substantially equal to ⅕ of the total length of the slat, thus leaving a free span between the two pairs of lift/tilt cords of substantially ⅗ of the total length of the slats. But other arrangements, comprising even more than two systems of lift- and tilt cords could also be used for instance for very long slats.
According to an alternative embodiment of the venetian blind according to the invention, vertically extending support cords or equivalent means are provided at either longitudinal end of the slats in order to increase the overall stability of the venetian blind both longitudinally and laterally, i.e. in a direction substantially perpendicular to the plane of the venetian blind. For this purpose, the slats are at either longitudinal end hereof provided with support members attached to the slats and provided with suitable passages through the member for passage of the support cords.
According to still an alternative embodiment of the venetian blind according to the invention, the lift cords are—instead of running parallel with the tilt cords—guided along the support cords, for instance through the same or additional passages in the support members as the support cords. The lift cords are also in this case attached to the lowermost slat of the venetian blind.
It is a further object of the present invention to provide a simple and yet reliable lift- and tilt mechanism which can be preferably driven by a single drive means, for instance an electrical motor, operating all pairs of lift- and tilt cords of the venetian blind. It is however understood, that separate drive means could also be used for each pair of lift- and tilt cords without departing from the invention.
According to the invention the combined lift- and tilt mechanism is positioned on a longitudinally extending shaft driven for rotation by appropriate drive means such as an electrical motor. The drive means can either be placed external of the shaft or be incorporated into a hollow portion of the shaft.
The lift- and tilt mechanism according to the invention comprises a tubular member mounted for rotation with and axial displacement over said drive shaft and guide means for maintaining the lift cords in their proper axial position and for directing the lift cords to the outer circumferential surface of said tubular member, whereby the lift cords upon rotation of said tubular member will become helically wound on or off the circumferential surface of the tubular member resulting in the slats being raised or lowered as the tubular member rotates.
According to one embodiment of the present invention said tubular member on the outer circumferential surface hereof is provided with a single thread for accommodating each of said lift cords of a given pair of lift cords in the same thread.
According to another embodiment of the present invention said tubular member on the outer circumferential surface hereof is provided with a double thread for accommodating each of said lift cords of a given pair of lift cords in separate threads hereof.
In either of the above embodiments of the lift- and tilt mechanism according to the invention the rotation of the tubular member together with the fact that the lift cords extending downwards towards the slats are restricted from axial movement in itself makes the tubular member undergo axial displacement, whereby the lift cords wind on or off the tubular member in one single, axially extending layer of cord as the tubular member rotates with the drive shaft. However, according to a third alternative embodiment of the lift- and tilt mechanism according to the invention said single/double thread provided on the outer circumferential surface of the tubular member is in engagement with a corresponding thread in a stationary bearing supporting the tubular member, this arrangement giving rise to the axial displacement of the tubular member and facilitates the proper winding on or off of the lift cords on the tubular member. In the third embodiment of the invention a gap of sufficient dimensions is formed between said thread(s) on the tubular member and on the stationary bearing for accommodation of the lift cords in said gap.
According to the invention the lift- and tilt mechanism furthermore comprises tilt means for connection to the tilt cords of a given pair of lift- and tilt cords, said tilt means according to a first embodiment hereof comprising a cylindrical tilt house provided coaxially about said drive shaft and connected to this for co-rotation herewith, around the outer circumferential surface of which tilt house there is provided a tilt member following said rotation of the tilt house over a predetermined angular range due to friction between the tilt member and the tilt house. This range is determined by first means provided on the tilt member during said rotation being broad into contact with corresponding stationary abutment means. The tilt cords are wound around the tilt member, so that rotation of the tilt member in one direction makes one tilt cord of the given pair of tilt cords unwind from the tilt member and the other tilt cord of the given pair of tilt cords wind upon the tilt member. By proper dimensioning of the diameter of the tilt house and tilt member relative to the width of the slats the slats can be broad to undergo a tilting movement over an angular range of approximately 180 degrees, i.e. the slats can tilt between a substantially vertical position, where adjacent edges of the slats are in contact with each other to form one closed surface of the venetian blind through a horizontal position of the slats and to the opposite, substantially vertical position of the slats. Modifications of the ratio between the diameters of the tilt house/tilt member and the width of the slats can be used to restrict the angular tilt range, if desirable.
According to the invention the tilt member encircling the tilt house can be radially rigid, but it is also possible to provide the tilt member according to the invention with a certain degree of radial resiliency. Thus for instance a tubular tilt member could be provided with a gap radially extending through the tilt member. Radial resiliency of the tilt member has the advantageous effect that once the rotation of the tilt member relative to the tilt house, as described above, is stopped by said engagement with the abutment means continued rotation of the drive shaft and the tilt house (for lowering or raising the slats) will tend to increase the inner diameter of the tilt member due to the fact that one end of the tilt member is prevented from rotation and that a frictional force is exerted between the contact surface of the tilt member and the tilt house. Thereby the frictional force between the tilt house and the tilt member is reduced, which is advantageous from the point of view of the drive means driving the drive shaft and the tilt house. Thus by providing radial resiliency to the tilt member the drive means can use practically all of its power to raise or lower the slats without wasting power to overcome unnecessary friction between the tilt house and the tilt member. Substantial friction between the tilt house and the tilt member is thus only present, when it is needed, i.e. when the tilt of the slats must be changed, in which situation rotation of the tilt member is not prevented by engagement with the stationary abutment means.
In one version of a tilt means according to the first embodiment hereof, the tilt member is a tubular member comprising a main portion and a collar defining an intermediate groove for accommodating the tilt cords.
According to a second embodiment of the tilt mechanism according to the invention, the tilt mechanism is formed as a separate mechanism remote from the lift mechanism.
Generally, there exists a relationship between the width of the slats and the diameter of the tilt house and tilt member necessary for tilting the slats from a first vertical orientation through a horizontal orientation to an opposite vertical orientation of the slats. Thus, wide slats—for instance of a width of 20 to 25 cm—require a correspondingly large diameter of the tilt house and tilt member. It can, however, be desirable to be able to apply tilt mechanisms where the diameter of the tilt house and tilt member are limited even though slats of a considerable width are applied in the venetian blind. This problem is solved according to the invention by means of a specially advantageous embodiment of the tilt mechanism employing a double-stop function, according to which abutment means provided on the tilt member during rotation of the tilt member are not brought into engagement with stationary abutment means but with another rotational abutment means, whereby rotation of the tilt member around the tilt house can take place over an angle of more than 360 degrees around the tilt house. Eventually, the rotational abutment means will be brought to rest by abutment with a stationary abutment means provided for instance on the bearing supporting the tilt mechanism. By these means, rotation of the tilt member between 0 degrees and approximately 720 degrees around the tilt house can take place. It is even possible to extend this mechanism by providing a consecutive series of rotational abutment means, whereby the tilt member will be able to undergo a rotation around the tilt house of approximately N*360 degrees, where N is the number of such rotational abutment means+1, the number 1 accounting for the original tilt member. A specific embodiment of this alternative tilt mechanism is described in detail in the detailed description of the invention.
In order to prevent light from penetrating through the contact regions along the longitudinal edges of the slats portions of the regions of the edges of the slats can be provided with sealing material, such as felt, rubber etc.
A number of advantageous effects are attained by the venetian blind system according to the invention. Thus the attachment of the slats along the longitudinal edges hereof is highly advantageous from an aesthetical point of view due to the omission of passages cut through the main portion of the slats, as it is typically done in most known venetian blind systems for passage of a lift cord. The absence of passages through the main portion of the slats is also advantageous from the point of view of controlling of passage of light through the venetian blind. In venetian blinds comprising very large slats as is typically the case in connection with the venetian blind according to the invention comparatively large passages would have to be provided through the slats for the passage of a lift cord, and such passages would have to extend over a substantial portion of the width of the slats in order to make it possible to tilt the slats to their two substantially vertical positions. Thus even if corresponding edge portions of adjacent slats were brought into tight contact with each other—in order to prevent light from penetrating the venetian blind—light would still penetrate said comparatively large passages in the slats. A complete darkening of the room would hence not be possible with slats comprising said passages, but can be attained with the venetian blind according to the invention. If necessary sealing material, such as rubber, felt etc. can even be provided at the edge portions of the slats to prevent light from penetrating between adjacent slats.
Also from the point of view of cleaning the slats it is advantageous to have large, unbroken surfaces of the slats without cords penetrating the slats.
Furthermore, as mentioned initially, the presence of the longitudinal edge portions along either edge of the slats increases the overall rigidity of the slats thus providing for venetian blinds of great longitudinal extension, typically with the application of only two pairs of lift- and tilt cords. It is thus possible to cover large surfaces, not necessarily only window openings, with a single venetian blind, having large extensions both horizontally and vertically.
The attachment of the tilt cords along the edge portions makes both initial assembling of the venetian blind easy and also facilitates removal and replacement of single slats without the necessity to dismantle major parts of the whole venetian blind. The easy initial assembling of even venetian blinds of considerable dimensions furthermore opens up for the possibility to purchase the venetian blind in the form of a kit to be easily assembled in situ. The slats can for instance be kept in stock in form of very long slats, which can be sold in the lengths actually needed. The ease of assembling the venetian blind in situ is also advantageous from a transportation point of view.
Also from a production point of view the unbroken surface of the slats together with the fact that the slats can be made in one piece for instance with the aid of a roll forming technique is highly advantageous.
Finally the slats may be used for altering the acoustical characteristics of a room by the provision of the various forms of acoustic damping arrangements on the slats. The tilting of the slats can even be utilised to alter the acoustical effect of the slats, it being possible to obtain either an acoustical hard surface, when the slats are in one of their vertical positions, or various degrees of acoustical damping, when the slats are tilted.
In order to obtain an aesthetically satisfactory effect, it is important to suspend and operate the slats of the Venetian blind in a manner that ascertains proper alignment of all slats both in situations where the slats are stationary and during raising, lowering and tilting operations of the slats, as even minor deviations from proper alignment may subtract materially from the overall appearance of the Venetian blind. Wind-up systems where the cords are layered on top of each other would inevitably lead to length deviations between cords and pairs of cords which would cause the slats to be unevenly raised. This kind of lift systems would also cause variations in lift speed.
In order not to get the cords entangled, a certain amount of tightening up of the cords is normally necessary. In the above arrangement, the weight of the slats is considered sufficient load of the cords for pulling the cords out of the mechanisms during lowering of the slats and retaining the cords in position during wind-in of the cords while raising the slats. But different tilt angles can lead to one cord of a pair being slack, and at lower weight of the slats or certain wind situations, the need for active tightening might not be fulfilled causing the lift cords to be entangled, which in turn can lead to disorder of the cords in the lift mechanism and even cause damage of the mechanism.
On this background, it is a further object of the present invention to provide lift mechanisms for instance for use in Venetian blinds of the above-mentioned kind, where the lift cords are actively pushed out of or held outside the mechanism without possibility of entangling the cords inside the mechanism.
It is another object of the present invention to present a mechanism that can be axially connected in cascade for provision of a plurality of pairs of cords driven for rotation by the same or separate winding motors such as electrical gear motors.
The lift mechanism according to this specific embodiment of the invention comprises a spool shaft mounted for rotation with an axial displacement over said drive shaft within a concentric tubular housing and guide means for maintaining the lift cords in their proper axial position and for directing the lift cords to the outer circumferential surface of said spool shaft, whereby the lift cords upon rotation of said spool shaft will become helically wound on or off the circumferential surface of the spool shaft resulting in the slats being raised or lowered as the spool shaft rotates with constant relationship in velocity of the cords to the rotation of the drive shaft.
Since the lift cords are restricted from axial movement with respect to the slats and the wind-in of the pair of lift cords on the spool shaft is supposedly wound in one layer only in a helical way, an axial displacement of the spool shaft is necessary and this axial displacement in the present invention is advantageously controlled by the rotation of the drive shaft, hereby controlling the winding pitch.
According to a specific embodiment of the invention, which will be described in more detail in the detailed description of the invention, the axial displacement over the drive shaft is controlled by means of a rack and pinion system, where the circumferentially threaded pinion is rigidly connected to the spool shaft and rotationally coupled to the drive shaft, and the threads are in engagement with the stationary rack, said pinion operating as the axial driving means for the spool shaft in synchronisation with the drive shaft hereby controlling the pitch of the helical winding of the lift cords onto the spool shaft.
According to an alternative embodiment of the invention, the drive shaft of the lift mechanism in one or both ends has means for connecting to drive motors such as electric gear motors and/or shafts of other lift mechanisms for cascading of mechanisms when more pairs of lift cords are needed, for instance for longer venetian blinds or systems of venetian blinds.
The arrangement of unwinding of pairs of lift cords in perfect synchronism allows for attaching the lift cords to the slats along the longitudinal edge portions, which makes both initial assembling of the venetian blind easy and also facilitates removal and replacement of single slats without the necessity to dismantle major parts of the whole venetian blind. The easy initial assembling of even venetian blinds of considerable dimensions furthermore opens up for the possibility to purchase the venetian blind in the form of a kit to be easily assembled in situ. The slats can for instance be kept in stock in form of very long slats, which can be sold in the lengths actually needed. The ease of assembling the venetian blind in situ is also advantageous from a transportation point of view.
Also from a production point of view the unbroken surface of the slats together with the fact that the slats can be made in one piece for instance with the aid of a roll-forming technique is highly advantageous.
The invention will now be described in more detail with reference to the accompanying drawings, in which
a and 3b are a view of a clip used for attachment of the slats to the tilt cords;
a and 4b are cross-sectional views of two alternative slats according to the invention;
c and 4d are alternative attachment means for the slats shown in
a is a schematic perspective view of the tilt mechanism according to the invention;
b is a schematic view of the tilt mechanism according to the invention as seen from one longitudinal end of the tilt mechanism;
a, 10b and 10c are schematic representations of alternative routings of lift cords to the tubular member of the lift mechanism;
a is a schematic representation of a venetian blind according to an alternative embodiment of the invention comprising lateral support cords to enhance stability of the venetian blind in the longitudinal direction of the slats;
b is a schematic representation of a detail of the venetian blind shown in
In the following a detailed description of a presently preferred embodiment of the invention is given.
With reference to
The slat according to this embodiment may be produced in a simple manner by known techniques, such as roll forming.
With reference to
A number of attachment means could be envisaged for the slats according to the present invention. The prime prerequisite for these attachment means is their ability to pass through the gap between the first and second edge portions of the slat and to be retained within the space between these portions after passage through the gap.
With reference to
With reference to
The attachment means shown in
With reference to
Around the shaft 33 there is provided a tubular member 36 dimensioned for rotation with the shaft 33 and for axial displacement over a predetermined longitudinal distance of the shaft 33, this displacement being indicated by the arrow C in
As shown in
A second embodiment of the lift- and tilt mechanism according to the invention is shown in
According to a third embodiment of the lift- and tilt mechanism according to the invention (not shown) the single thread comprised in the second embodiment is replaced by a double thread, each thread accommodating one of the lift cords 20 of the given pair of lift cords.
According to a preferred version of the above second and third embodiments of the lift- and tilt mechanism according to the invention the inner circumferential surface of a cylindrical tilt house 41, which will be described in the following, substantially touches the crests of the thread 39 on the tubular member 36, whereby substantially closed spaces for accommodating the lift cords 20 are formed between the tubular member 36 and the inner circumferential surface of the cylindrical tilt house 41, thus preventing the lift cords 20 from becoming entangled or leaving contact with the tubular member 36 during operation of the mechanism.
In order to be able to accommodate the lift cords 20 in the region between the tubular member 36 and the stationary bearing 40 a sufficient space must of cause be provided between the corresponding threads as depicted in
With reference to
Referring to
In the state shown in
In the state shown in
An alternative embodiment of the lift- and tilt mechanism according to the invention is shown in
The drive shaft is in
Referring now to
Tilt cords 19 are directed from the slats via suitable systems of pulleys (for instance 69) and wound around the tilt member in a manner corresponding for instance to that shown previously in connection with the first embodiment of tilt mechanism. Such tilt cords are indicated in
The range of rotation of the rotatable abutment ring 64—and hence of the tilt member 61 around the tilt drum 60—is determined by the circumferential extent of the abutment portion 66. Hence, by proper choice of the circumferential extent of the abutment portion, the desired rotation range can be set.
With reference to
With reference to
The slats can as an option be provided with resilient bands in contact regions between adjacent slats in order to prevent light from penetrating the contact regions between the slats. Also such resilient bands would prevent the generation of noise when adjacent slats are broad into contact with each other during operation of the venetian blind.
With reference to
The provision of the support members 72 or equivalent members at the longitudinal ends of the slats leads to a further alternative embodiment of the venetian blind according to the invention. As shown in
In the following, a detailed description of a presently preferred embodiment of the lift mechanism according to the invention is given.
With reference to
The circumferentially threaded pinion 85 and the cord lock 84 are in rotational engagement with the drive shaft 76 by means of a groove and tongue system. By means of protruding fingers and dents said circumferentially threaded pinion 85 and said cord lock 84 are engaged in corresponding notches in each end of the spool shaft 77. The circumferentially threaded pinion 85, the cord lock 84 and the spool shaft 77 hereby constitute a rotating and axially displaceable mechanism. The housing part 80 with cord guide means 96 (
In the present embodiment, the lift cords during winding will be tightly packed with no possibility of getting displaced or entangled. By counter rotating said mechanism, the lift cords will be unwound and pushed out of the cord channels 91 because of the rotation simultaneous with an axial displacement in the reverse direction of that from the wind-in sequence. In an advantageous embodiment, the outer periphery of the spool shaft 77 is treated to yield higher frictional force to the lift cords than the inner periphery of the tubular housing 78. The complete assembly can be fixed to a building part by means of the housing parts 80 and 82 and the flange 89.
With reference to
With reference to
Although only a limited number of embodiments of the present invention have been shown and described in the preceding parts of the detailed description, it is understood that a person skilled in the art may conceive other embodiments of the invention without departing from the scope of the invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003 00485 | Mar 2003 | DK | national |
This application is a continuation-in-part of application Ser. No. 10/551,519 filed Jun. 9, 2006 now U.S. Pat. No. 7,654,301, which is the National Stage of International Application No. PCT/IB2004/050363, filed Mar. 30, 2004 (which is hereby incorporated by reference).
| Number | Name | Date | Kind |
|---|---|---|---|
| 3181595 | Pender | May 1965 | A |
| 4200135 | Hennequin | Apr 1980 | A |
| 5725040 | Domel | Mar 1998 | A |
| 5839494 | Judkins | Nov 1998 | A |
| 7540315 | Chen | Jun 2009 | B2 |
| 7654301 | Krab et al. | Feb 2010 | B2 |
| 20060249264 | Lin | Nov 2006 | A1 |
| 20100155000 | Krab et al. | Jun 2010 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20100155000 A1 | Jun 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10551519 | US | |
| Child | 12640137 | US |
