WO2016189424A1 - An improved lateral withholding system for roller screens, such as mosquito nets and curtains - Google Patents

Abstract

An improved lateral withholding system for roller screens (3), which is equipped with fixed or flexible perimetral guides, said roller screens being constituted, for example, by mosquito nets, or sheets, or blinds, wherein each of said guides envisages at least one device for anchoring the net (3), which is constituted by a series of pawls (4) made of rubber that are arranged radially around a central body (5) that is free to turn about its own axis; thus obtaining that, while the net screen (3) is sliding within the guide and passes alongside said anchoring device, said pawls (4) penetrate between its meshes so that the net (3) itself will remain constrained thereto; for this purpose, the size of the pawls (4) is such that they can penetrate into the meshes of the roller net (3).

Description

AN IMPROVED LATERAL WITHHOLDING SYSTEM FOR ROLLER SCREENS. SUCH AS MOSQUITO NETS AND CURTAINS

The present invention relates to the sector of door and window frames, and in particular installation of screens of the roller type.

The main purpose of a screen is notoriously to prevent insects (in the case of mosquito nets) from entering the internal premises of offices or dwellings at the openings in the walls.

Known to the art are technical solutions in which, for convenience, the above screens can be temporarily removed from the corresponding opening by rolling them up in a purposely designed container box. in other words, the roller screen basically consists of a sheet stretched between two uprights profiles, of which at least one is mobile and can be operated by the user, said sheet having the other two sides inserted in respective lateral guides in order to guarantee - throughout the perimeter of the sheet - the impossibility for the insects to pass through the barrier represented by the screen when the two uprights profiles are located on the two opposite sides of the structural opening to be screened.

The typical composition of this type of roller screens (which are basically designed for openings of a quadrangular shape) hence envisages a sheet set between a first, box, sectional element (which contains a winding drum around which the sheet is wound up) and a second, mobile, sectional element (referred to as handle), via which the sheet itself can be rolled up or unrolled.

As regards to the other two free sides, the sheet is contained by sectional elements referred to as "lateral guides".

The lateral guides, which may be of a fixed or hide-away type, have the dual function of guiding sliding of the handle sectional element and of enclosing the free lateral edges of the sheet, thus guaranteeing complete closing of the opening, a characteristic that is necessary for proper operation of the screen.

in the case of wind, the sheet of the screen, firmly held by the box on one side and by the handle on the other, may, however, come out of the guides set on the other two sides, and the condition of complete closing of the opening thus ceases, in the case of roller mosquito nets, the sheet is notoriously constituted by a net with meshes sufficiently small to prevent passage of mosquitoes.

Given what has been said above, the sheet is permanently constrained to the uprights profiles (being mechanically slotted therein on one side and rolled around a rolling drum on the other), whereas in the guides, in which the sheet is required to slide freely, various systems are currently used to prevent the screen from coming out from the guides themselves.

A known system envisages, for example, providing along the guide brushes for withholding the sheet, which have their bristles facing the sheet itself, in this technical solution, the bristles of the brushes, in the event of wind, pass through the meshes of the net screen and withhold it in place, preventing the perimetral edge thereof from coming out of the guides.

The action of the above brushes, however, is not always effective, and frequently their bristles bend under the action of the wind on the roller screen, which even so comes out of the guides.

Another system that is extensively used consists in providing, along the edges that are to slide along the guides, small studs, having a transverse dimension slightly greater than the width of the groove of the guide within which the screen slides, in the event of wind, the stud remains imprisoned in the guide, thus preventing exit of the net from the guide. The presence of said studs, however, causes an increase in the friction and a greater resistance to sliding of the roller net along the guides themselves. Moreover, said studs cause a considerable increase in the rolling diameter of the screen, which entails the need to reduce considerably the dimensions of the sheet or else to adopt more complex and costly manufacturing sol utions .

EP1905944 describes a roller-screen device provided with fixed or flexible perimetral guides that does not envisage any system for withholding the edges of the roller screen.

EP2775088 regards a roller-screen device similar to the previous one, but which envisages means for withholding the edges of the roller screen that are constituted by lateral tabs fixed to the edges of the screen .

EP0797722 describes a roller-screen device equipped with withholding means constituted by sort of brushes provided in the lateral guides, which are fixed and rigid.

These known technical solutions envisage particular conformations of the edge of the sheet and of the guides, but entail higher costs for production of the sheet or else are far from being effective.

The main purpose of the present invention is to overcome the drawbacks indicated above by withholding the edge of the sheet with a new system that will provide an effective withholding action and that will simultaneously ensure a movement of sliding of the sheet along the guides.

A better understanding of the invention will be obtained from the ensuing detailed description and with reference to the attached drawings, which illustrate, purely by way of non-limiting example, a preferred embodiment of the invention, applied to the case of flexible guides, i.e. , guides that are retractable in the vertical sectional elements when the screen is rolled up.

in the drawings:

Figure 1 is a 3D view of the hide-away flexible guide, with at least one element for withholding the net screen;

Figures 2 and 3 show a generic element (i.e. , a link) of the flexible guide, in 3D view respectively from beneath and from above;

Figures 4 and 5 show a link for withholding the net of the flexible guide, in 3D view from beneath and from above, respectively: in particular, Figure 5 illustrates the withholding device in exploded configuration dismantled from the corresponding link;

Figure 6 shows a stretch of flexible guide with net-withholding device that engages the net;

Figure 7 is a side view of the withholding device that engages the net; and

Figure 8, which is similar to the previous one, shows the withholding device that engages the net, with the net that is subject to a side wind.

with reference to the figures listed above, in the drawings the net-withholding device 3 according to the invention is shown in the case of application in a guide of a flexible type, i.e., a guide constituted by a series of links 1, 2 hinged together to form a sort of chain, which in the periods of non-use (sheet 3 rolled up) can be hidden away in at least one of the uprights profiles (not shown). Hereinafter said uprights profiles will be simply called "uprights". it is evident, however, that the same result can be achieved by applying - without modifications - the invention to traditional rigid guides.

Basically, according to the present invention, the flexible guide is made up of rigid elements 2 hinged together as if they were the links of a chain, and envisages at least one element 1 (i.e., at least one of these links) that is equipped with the device for anchoring the net, which is shown in the figures and will be better described in what follows.

According to a peculiar characteristic of the invention, the anchoring device is constituted by a series of pawls 4 made of rubber arranged radially around a central body 5 that is free to turn about its own axis; as the portion of screen 3 that is sliding within the flexible guide passes alongside the device, the pawls 4 penetrate between its meshes (the size thereof allows this) and remains constrained thereto.

From what has been said and shown in the figures, it is clear that the axis of rotation of the central body 5 of the anchoring device present in each of the elements 1 is set transverse with respect to the flexible guide, in a direction parallel to the plane of the roller screen.

in static conditions (i.e., with the screen 3 activated, i.e., unrolled) the pawls 4 do not enable exit of the sheet 3 from the guide in the presence of wind, thus guaranteeing the effectiveness of the screen .

During operation, instead, the pawls 4 are designed to turn about the axis of the central body 5 of the anchoring device to follow the movement of rolling/unrolling of the roller screen 3.

Advantageously, the movement of sliding of the sheet 3 during opening and closing of the screen is not hindered, even though the pawls 4 are always engaging, performing their function without any interruption and without generating any sticking.

it should be pointed out that one of the main advantages of the invention consists precisely in the simplicity of construction and in the possibility of preventing the need to carry out particular processes on the sheet 3 in order to apply withholding devices along its edges. These processes, in fact, would require time and particular machinery, whereas the device described herein represents an article that is immediately ready for the manufacturer of the screen 3.

As compared to the currently known guides with withholding brushes, the present invention has the advantage of constantly engaging the sheet 3, whereas the bristles of the brush are effective only when the net is in static conditions.

The present invention has been described and illustrated as regards a preferred embodiment, but it is evident that functionally and/or technically equivalent modifications and/or replacements may be made by the person skilled in the branch, without thereby departing from the sphere of protection of the present industrial patent right.

Claims

1. A lateral withholding system for roller net screens (3), which is equipped with fixed or flexible perimetral guides, said roller screens being constituted, for example, by mosquito nets, or sheets, or blinds, said system being characterized in that each of said guides envisages at least one device for anchoring the net (3), which is constituted by a series (4) of pawls made of rubber that are arranged radially around a central body (5) that is free to turn about its own axis; thus obtaining that, while the net screen (3) is sliding within the guide and passes alongside said anchoring device, said pawls (4) penetrate between its meshes so that the net (3) itself will remain constrained thereto; for this purpose, the size of the pawls (4) is such that they can penetrate into the meshes of the roller net (3).

2. The improved system according to the preceding claim, characterized in that, in the case where at least one of the guides is of the flexible type, it is made up of rigid elements (2) hinged together as if they were the links of a chain, and envisages at least one rigid element (1) hinged to the others that is equipped with the device for anchoring the net screen (3) to the guide itself.

3. The improved system according to Claim 1 or

Claim 2, characterized in that the axis of rotation of the central body (5) of the anchoring device is set transverse with respect to the flexible guide, in a direction parallel to the plane of the roller net screen .

4. The improved system according to at least one of the preceding claims, characterized in that in static conditions, with the net screen (3) activated, i.e., unrolled, at least some of the pawls (4) traverse the thickness of the sheet (3) preventing exit thereof from the guide even in the presence of wind, thus guaranteeing effectiveness of the screen.

5. The improved system according to at least one of Claims 1 to 3, characterized in that, during operation, i.e., while the sheet of the net screen (3) is sliding in the guides, the pawls (4) are designed to turn about the axis of the central body (5) of the anchoring device, to follow, without hindering it, the movement of rolling/unrolling of the roller net screen (3); wherein, during said rotation, the pawls (4) traverse the thickness of the screen itself to prevent it from possibly coming out of the guide.

6. The improved system according to the preceding claim, characterized in that the movement of sliding of the sheet (3) during opening and closing of the screen is not hindered even though the pawls (4) are always engaging, performing their function without any interruptions and without generating any sticking.