A mosquito screen comprises a shielding net (3) rolled up on a winding roller (5) and having an end edge (3a) fastened to an upright (4). The winding roller (5) is rotatably housed in a movable bar (6) moving away from the upright (4) to determine spreading of the shielding net (3) in the plane of the window opening (2) with which the mosquito screen is associated. A movable holding member (7) is fastened at a terminal portion thereof to one end of the movable bar (6) and has a length (7b) slidably engaged at the inside of the upright (4) and connected to the opposite end of the movable bar (6) by a synchronisation cable (10) extending on transmission elements (11a, 11b, 11c).
|6318438||Net guide for side-sliding wire screen|
The present invention relates to a roll-up mosquito screen, of the type comprising the features set out in the preamble of claim 1.
It is known that roll-up mosquito screens essentially comprise a shielding net rolled up on a receiving or winding roller usually housed in a box-shaped structure fastened along one side of the window or French window on which the mosquito screen is installed. An end edge of the net is secured to a movable bar having the opposite ends slidably guided along guide section members fastened along two opposite sides of the window, at right angles to the side carrying the roller-holding structure. The movable bar lends itself to be manually moved away from the rewinding roller to cause unrolling of the shielding net and spreading of same in the lying plane of the window or French window.
Under an end-of-stroke condition, the movable bar is fastened to a section member anchored to the window side opposite to the one carrying the holding structure of the rewinding roller. When there is no need for the mosquito screen, and/or the passage through the window or French window is wished to be used, the movable bar can be released from the respective hooking section member to allow rewinding of the net on the winding roller by suitable spring means loaded in the preceding net-unrolling step.
The Applicant has found that mosquito screens of the above described type can be improved under different points of view.
For example, in the products made in accordance with the known art it is not possible to keep the roll-up net in a partly extended condition, with the movable bar spaced apart from the respective hooking section member, unless rather complicated braking systems are adopted which however give rise to an increase in the product cost and reduce the operating reliability of the product itself in time.
In the products of the known art, in addition, the shielding net can be easily damaged should it, for any accidental reason, interfere with an object upon movement of the net itself both during the winding and the rewinding steps.
Moreover, known mosquito screens can be hardly adapted to possible geometric and size inaccuracies of the window openings. Obviously and furthermore, known mosquito screens can be hardly adapted to windows of various different sizes, both in height and width.
Accordingly, it is an aim of the present invention to obviate the drawbacks of the known art, by proposing a roll-up mosquito screen overcoming said drawbacks.
The above and further aims that will become more apparent in the course of the present description are substantially achieved by a roll-up mosquito screen comprising the features set out in the characterising portion of claim 1 and/or in one or more of the following claims.
Further features and advantages will be best understood from the detailed description of a preferred, but not-exclusive embodiment of a roll-up mosquito screen in accordance with the present invention.
This description will be set out hereinafter with reference to the accompanying drawings, given by way of non-limiting example, in which: Fig. 1 is a diagrammatic front view of a mosquito screen in accordance with the invention in a condition of partial unrolling of the shielding net; Fig. 2 diagrammatically shows a section thereof to an enlarged scale, executed along line II-II in Fig. 1; Fig. 3 shows an enlarged detail of the mosquito screen in reference, sectioned along line III-III in Fig. 1; Fig. 4 shows a further detail, to an enlarged scale, of the mosquito screen in reference, sectioned along line IV-IV in Fig. 1.
With reference to the drawings, a roll-up mosquito screen in accordance with the present invention has been generally identified by reference numeral 1.
The mosquito screen 1 lends itself to be typically installed at an opening 2 of a window or French window usually having a first and a second vertical sides 2a, 2b, a lower horizontal side 2c and an upper horizontal side 2d.
The mosquito screen 1 comprises a shielding net 3 currently of synthetic material, having square meshes of a width included between 0.3 and 2 mm for example, so as to provide an efficient barrier to passage of small insects such as mosquitos, while ensuring an effective perviousness to air.
The shielding net 3 having a substantially rectangular extension has an end edge 3a that can be brought into rigid engagement with a load bearing structure represented by or defined at one of the sides of the window opening 2. In more detail, in the described embodiment the first end edge 3a of net 3 is fastened to a support section member or upright 4 to be rigidly engaged along the first vertical side 2a of the opening 2. On the opposite side from the first end edge 3b the shielding net 3 has a second end edge 3b fastened to a winding roller 5 that, with the aid of spring return devices not described as they can be made in any known manner, lends itself to be driven in rotation to cause rewinding of the shielding net 3 on the winding roller 5 itself.
The winding roller 5 is rotatably housed within a movable bar 6 consisting of a box-shaped section member, extending parallel to the upright 4 and movable, in a horizontal direction for example, away from and close to the upright itself, as shown by arrow "A" in Fig. 1. On moving of the movable bar away from the upright 4 unrolling of the gathered net 3 occurs and extension of same in the plane of the window opening 2, against the action of the spring return means associated with the winding roller 5.
On moving of the movable bar 6 close to the upright 4, on the contrary, rewinding of the net 3 within the movable bar itself occurs, upon the action of the above mentioned spring return means.
Fastened to at least one of the ends of the movable bar 6, in the instance herein shown the first end 6a disposed below, is a first end of a movable holding member 7 having a first length extending between the movable bar 6 and upright 4, and a second length 7b slidably guided along the upright itself, preferably at the inside of said upright. The movable holding member 7 is longitudinally dragged along by movement of the movable bar 6 so that the first length 7a thereof is stretched along a corresponding side edge 3c of the shielding net 3, that therefore is maintained slidably engaged in a holding seat 8 defined in the movable holding member itself, and conveniently retained in respect of side and/or vertical displacements.
In a manner known by itself, the movable holding member 7 can be made for example in the form of a flexible ribbon of plastic material, or it may consist of a plurality of consecutively hinged elements in the same manner as the links of a chain, so that said member can be easily bent to deviate its movement-trajectory when entering the upright 4 and coming out of same, in the transition between the first length 7a and the second length 7b.
Also preferably associated with the movable holding member 7 is a fixed slide or guide 9 extending away from the upright 4 along the movement trajectory of the movable bar 6, at a respective side of the opening 2, the lower horizontal side 2c, for example.
The fixed guide 9 can advantageously have a flattened rectangular section, as shown in Fig. 3, the major axis of which is perpendicular to the lying plane of the shielding net 3 in the length included between the upright 4 and the movable bar 6. The fixed guide 9 is thus substantially disposed completely level with the corresponding side 2c of the opening 2, which is particularly advantageous when the mosquito screen 1 is associated with a French window, as in the example shown. In this case, in fact, the presence of the fixed guide 9 does not give rise to particular discontinuities with respect to the floor plane "P".
The fixed guide 9 thus engages the movable holding member 7 at a seat 9a defined between projecting wings 8a of the holding member itself.
Alternatively, the fixed guide 9 seen in section can have a T-shaped configuration or other shape adapted to define an undercut for engagement of the movable holding member 7 at respective undercut tailpieces defined on wings 8a.
Further associated with the movable holding member 7 can be at least one synchronisation cable or string 10 having an end fastened at the terminal portion thereof to the second length 7b of the movable holding member and a second end fastened to the movable bar 6, preferably in the vicinity of a second end 6b of the bar itself or in any case at a point conveniently spaced apart from the first end 6a with which the movable holding member 7 is linked.
Suitable transmission elements 11a, 11b, 11c engage the synchronisation cable 10 so as to define therealong a first length 10a extending along the upright 4 until a first transmission element 11a fastened in the vicinity of the upper end of said upright.
Consecutively of the first length 10a, a second length 10b of cable 10 extends from the first transmission element 11a to a second transmission element 11b, which is fixed as well with respect to the support section member or upright 4 and placed close to the second vertical side 2d of opening 2. Cable 10 also forms a third length 10c which is substantially parallel to the second length 10b and extends from the second transmission element 11b to the movable bar 6. A third transmission element 11c may be also provided and it is fastened to the movable bar 6 and can be positioned along the longitudinal extension direction of said bar, with the aid of a threaded element 12 for example, acting through an elongated slot 13a formed in a plate 13 carrying the third transmission element 11c.
Positioning of the third transmission element guarantees the parallelism between the second length 10b and third length 10c of the synchronisation cable 10. It may be also provided that at least one of said first and second transmission elements 11a, 11b should be positioned along a vertical direction, or in any case a direction almost perpendicular to the sliding direction of the movable bar 6, to ensure the parallelism between the second length 10b of the synchronisation cable 10 and the fixed guide 9 and/or the side 2c of opening 2 to which said guide 9 is secured.
Due to the presence of the synchronisation cable 10, the movable bar 6 can be maintained in an orientation constantly parallel to the upright 4 or in any case to the side 2a of opening 2 along which the edge 3a of net 3 is secured. In fact, to each translation of the lower end 6a of the movable bar 6, an identical translation of the movable holding member 7 corresponds, and therefore a translation of the upper end 6b of the movable bar itself connected with the holding member 7 through cable 10. For an easy starting adjustment, the fastening point of the cable end may be provided to be positioned along the movable bar 6, by means of a slider 14 for example retaining the cable end and adapted to be secured along the bar itself by means of a screw 14a.
Also preferably provided is an auxiliary guide structure 15 extending away from the upright 4, along the upper horizontal side 2d of opening 2, and slidably engaging the movable bar 6 close to the upper end 6b thereof, opposite to the end linked to the movable holding member 7.
The auxiliary guide structure 15 can advantageously have a pair of holding walls 15a extending at laterally opposite positions with respect to the end 6b of the movable bar 6, and the extension of which is adapted to allow the movable bar 6 and the net side edge 3d opposite to the fixed guide 9 to be received therein for an insertion amount to be adjusted depending on the sizes of the opening 2, and more specifically on the distance between the horizontal sides 2c, 2d parallel to the movement direction of the movable bar 6.
The mosquito screen in reference therefore can be easily adapted, within limits, to openings of different sizes, both in height and width. In fact, adaptation in height, or in any case as regards the size measured at right angles to displacement of the movable bar 6, is obtained by conveniently adjusting the insertion degree of the ends 6b of the movable bar 6, of the corresponding side edge 3d of the shielding net 3, and of the end of the upright 4, between the holding walls 15a of the auxiliary guide structure 15, as above described. The presence of the third transmission element 11c to be positioned in a longitudinal direction with respect to the movable bar 6 allows the parallelism of the third length 10c of cable 10 to be ensured irrespective of the insertion degree of the movable bar between the holding walls 15a.
Adaptation of the movable bar 6 in the sliding direction is on the contrary determined by the fact that the shielding net 3 can remain partly rolled up on the winding roller 5 for the possible length exceeding the size of opening, when the movable bar 6 is brought to the end of its stroke away from the upright 4.
Use of the mosquito screen in reference is very simple. In fact, it is sufficient to manually move the movable bar 6 away from the upright 4, until bringing said bar against the second vertical side 2d opposite to the upright, to cause spreading of the shielding net 3 in the plane of opening 2. Due to the weight of the movable bar 6 and the winding roller 5 enclosed therein, and possibly also due to the static friction generated by contact of the movable holding member 7 on the guide structure 9 and the upright 4, a steady positioning of the movable bar 6 against the side 2b of opening 2 is ensured, without making it necessary to use any fastening means.
To increase steadiness of the movable bar positioning, friction means may be also provided that acts on the movable holding member 7, the fixed guide 9 and/or cable 10, to conveniently counteract the action of the spring return means associated with the winding roller 5.
For further reliability, in any case, use of auxiliary locking means is provided that can for example comprise a cam protrusion fastened to the guide end 9 opposite to upright 4 and designed to interfere with the movement of the movable bar 6 to the end-of-stroke position to cause a slight lifting of said bar and, as a result, engagement between a fitting element carried by the end 6b of the bar itself and a respective coupling seat formed in the auxiliary guide structure 15. Alternatively, the locking means may comprise magnetic elements operating between the movable bar 6 and an auxiliary upright for example, fastened along the second side 2b of opening 2.
The steady positioning of the movable bar 6 is advantageously obtained also when said bar takes any intermediate position between the upright 4 and the end-of-stroke position. This is an important advantage from a practical point of view, because the movable bar 6 shall be never returned abruptly towards the upright 4 upon the action of said spring means, when it is not retained by the user. The shielding net 3 therefore can also remain in a partially unrolled condition, to free the passage through opening 2 without necessarily being obliged to completely return the shielding net 3 to the winding roller.
It is also to be noted that the portion of the shielding net 3 exposed to the outside of the movable bar 6, fastened by its end edge 3a to the upright 4, remains absolutely motionless in its position during translation of the movable bar close to and away from the upright 4. Due to the absence of movement of the exposed portion of the shielding net, the risk of damaging said net as a result of accidental interferences with any object is greatly reduced.
In addition, in the mosquito screen in reference the movable bar may be provided to be fastened, by said fastening means or constraint means of other type, to an upright belonging to a contiguous mosquito screen. Thus it is possible to provide construction of a shielding device to be installed also outdoors to inhibit insects from entering a given environment, by disposing several mosquito screens one after the other, each having its movable bar fastened to the upright of the contiguous mosquito screen.