SAFETY DEVICE FOR SCREENS ON TUBE, PARTICULARLY FOR TECHNICAL CURTAINS, MOSQUITO NETS, NETS AND ROLLER SCREENS, AND RELATED INSTALLATION AND UN-INSTALLATION PROCESSES OF SUCH DEVICE

The present invention relates to a safety device for screens on tube, particularly for technical curtains, mosquito nets, nets and roller screens, and to related installation and un-installation processes of such device.

As known, the screens on tube in general are equipped with an actuating spring that must be pre-loaded upon installing the tube itself. Such operation is difficult and dangerous for the following reasons: it is difficult to block the spring in position; for installing/un-installing the device, it is necessary to use a tool (screw-driver) often in difficult positions; it is necessary to remove the spring-blocking pin under the same situation; the fact of removing the roller from its seat for correcting the spring tensioning, unavoidably implies freeing the spring, with consequent risk of releasing

approximately 25 J of elastic energy uncontrollably, while one is operating next to the dangerous area.

Moreover, prior art solution (as shown in Fig. 1) provide for a bushing A equipped with key B to be inserted exactly into the tube 3, and this operation, under above mentioned difficult conditions, is still more severe, with the risk of not correctly inserting the bushing key into the groove, distorting it with consequent locking of the whole winding device.

Object of the present invention is solving the above prior art problems, by providing a safety device equipped with a unrolling-preventing ratchet gear, suitable to keep the spring in position when it is being loaded.

Such device is automatically disconnected when inserting the roller in its working seat, and is reconnected as well when the roller is withdrawn.

For inserting and un-inserting the tube in its seat, no tools are necessary, and the hands simply work by tightening it next to its central part, which is a free and easy area.

The spring area that has risks of being freed (that anyway remains blocked) is at a safety distance from the operator.

The above and other objects and advantages of the invention, as will appear from the following description, are obtained with a safety device as described in claim 1,

and with processes for its installation and un~installation as described in the related claims .

Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims .

The present invention will be better described by some preferred embodiments thereof, provided as a non-limiting example, with reference to the enclosed drawings, in which:

- Figure 1 is a detailed perspective view of a prior art solution, and has been already previously described;

- Figure 2 is a detailed perspective view of a solution that uses the safety device of the present invention;

- Figure 3 is a perspective view of an embodiment of the safety device of the present invention in its closing position;

- Figure 4 is a perspective view of an embodiment of the safety device of the present invention in its opening position;

- Figure 5 is a perspective view of the device of Figure 3 with a handle for loading the spring (the handle is shown as an example, but any manual or automatic device suitable for loading the spring with the correct elastic distortion, can be used) ;

- Figure β is a perspective view of the device of Figure 7 inserted in a sectioned tube;

Figure 7 is an exploded perspective view of the safety device of Figures 3 to 6; and

- Figure 8 is a perspective view of another solution in which the safety device of the present invention is installed.

With reference to the Figures, a preferred, but not limiting, embodiment of a safety device 1 according to the present invention is shown. It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with eguivalent functionality) can be made to what is described, without departing from the scope of the invention as appear from the enclosed claims .

Such safety device 1 is adapted to be used on tubes 3 equipped with screens 2, that are commonly, but not in a limiting way, technical curtains, mosquito nets, nets and roller screens. The device comprises: means 5, 6 for loading a spring 7 for actuating the tube 3 ; stopper means 16,18,19,20 adapted to assume: (a) a safety position, before assembling the tube 3 in its operating position, in which they keep the spring 7 un-movably loaded; and (b) an opening position, after assembling the tube 3, in which they release the spring 7 allowing the screen 2 placed onto the tube 3

to be unwound and rewound in its use positions. In particular, the device equipped with stopper means is composed of: an engaging pin 10 adapted to transfer a twisting moment and to support the device assembly. Such pin 10 is shown in a square form, but any shape different from the circular one can be adopted; a circular section of the pin 9 adapted to allow rotating the bushing 16 that supports the roller tube 3 an auxiliary small spring 15, adapted to mutually push the blocking means 19, 16 by mutually engaging them and ^' blocking the safety device 1; a sliding or revolving bearing 27 (optional) adapted to improve the tribology between pressing spring 15 and bushing 16; a bushing 16 equipped with key 17 adapted to be inserted into the tube 3 and to support it, allowing its rotation around the circular section of the pin 9.

It is obvious that what has been described above is only the currently preferred embodiment of the stopper means, but afterwards they could be made in any other shape, configuration and arrangement or number of parts, provided that the final functionality for which they are provided is

obtained.

Still preferably, the bushing 16 has in its front section some teeth 18, shaped as saw teeth, adapted to engage the pin 19 - integral with the pin 9 due to the assembling screw 21 - with the respective antagonist teeth 20, thereby allowing the pin 19 to rotate along a single direction. The small teeth 18 allow rotating the safety device 1 along the pre-charge direction of the spring 7, while, due to their engagement in the openings 20, they prevent the opposite rotation to the pre-charge direction, and therefore allow keeping the spring 7 at its final operating pre-load to which it has been set during its installation.

Moreover, the bushing 16 e equipped with at least one key 17 adapted to block the safety device 1 against the tube 3.

And finally the stopper means 9, 11, 13, 15, 16, 19 can further be equipped with at least one washer 27 adapted to improve the coaxial rotation of the first pin 9 inside the bushing 16.

In the preferred embodiment shown, the safety device 1 is further equipped with fastening means 21 adapted to keep mutually operatively connected said stopper means 9, 16, 19. Such fastening means 21 can be composed of at least one screw, of suitable elastic constraints, of an assembling

through adhesive or pegging.

As shown in Figures 2, 5 and 6, the loading means 5, 6 are adapted to engage the engagement head 10 of the pin 9 for rotating the stopper means 9, 15, 19 together with the spring 7 end, and can be composed of a crank 5 (Figures 5 and 6), or also only of the head 6 (Figure 2) of a box 31 that is commonly used as housing of the tube 3.

As known, the spring 7 is further equipped, at its opposite end to the one in which the safety device 1 is inserted, with a dragging pin 23 adapted to engage, through at least one key 25, the tube 3 for dragging the tube 3 and the related screen 2 in its use positions.

The spring 7 is finally coated with a hollow cylinder 29 that prevents the spring from rubbing in the internal part of the roller tube 3, in order to reduce the noise induced by such rubbing.

In the embodiment made in this way, the safety device 1 is adapted to be operatively coupled with the tube 3 before its installation in a box 31, as can be well seen in Figure 2. Moreover, this arrangement can be applied to solutions of roller screens, in which case the spring will be freed upon inserting the device completed with tube and screen between the external supports 33.

Alternatively, the safety device 1 is adapted to be operatively coupled with the tube 3 before its installation

in an integrated system equipped with rollers that can be wound, through means for supporting the ends 33, but without dedicated containing boxes, as can be better seen in Figure 8. This configuration can be applied to solutions, such as for example integrated systems with roller shutter that can be wound, mosquito net and/or technical curtain, cinema screens, etc.

Particular installation cases of such screens 2 are with integrated systems already present on the market and in the field, that contain rollers that can be wound for shutters, or screens for projections.

In any case, the safety device 1 allows avoiding that the spring 7 is accidentally freed, thereby preventing the potential energy of the spring 7 from being freed till the spring 7, after having been inserted into the tube 3 and after the tube 3 has been equipped with the screen 2, is inserted in its operating position together with the roller tube.

The safety device 1 is installed through an installation process that comprises the main steps of:

- inserting the device 1 completed with spring 7 into the roller tube;

- loading the spring with potential energy through suitable manual or automatic loading means 5, 6;

- upon reaching the desired load, stopping the loading:

the device will remain under safety due to the automatic locking of the blocking means 19, 16, that occurs through the engaging teeth 18, 20 that are mutually pressed due to the auxiliary spring 15 and the bearing 27;

- upon installing the whole system equipped with tube and wound screen, the pressure on the engaging pin 10 will move away the teeth 18, 20 of the blocking means 16, 19 making the spring operating in its function of controlling the tube 3.

On the contrary, for un-installing the above-described safety device 1, a process is provided that comprises the main steps of: disconnecting the tube equipped with roller screen from the supports 33, or extracting the closing head

6 in case of its use with a box 31; following this, the pin 9 pushed by the auxiliary spring 15 goes out, dragging with it the pin 19 integral therewith, which engages its teeth 20 with the antagonist teeth 18 of the bushing 16; the spring 7 is blocked and keeps its charge under safety conditions; it is now possible to decide whether completely unloading the spring for completely un-installing the device, by pressing the engaging pin 10 against a

safe plane surface (for example the floor) , or modifying the load through suitable loading means (example 5) for better adapting it to use conditions and reinstalling the tube in its application.