ITTO20080596A1 - SAFETY DEVICE FOR DOORS WITH VERTICAL DOWNWARD. - Google Patents

Description

DESCRIPTION

The present invention relates to the field of accessories for vertical descent doors, and in particular it relates to a safety device for vertical descent doors.

As shown in figure 1, the vertical descent doors 1 of the known type are able to open and close an opening by means of a screen 2 capable of sliding inside two lateral guides 3.

The screen 2 can be of different types and for example consist of a uniform sheet, which is wound on a roller 4 positioned in the upper part of the door and which is moved by an electric motor 5 or, alternatively, be of the folding or panel type. rigid.

The folding screens 2 consist of a plurality of sections 6 mutually constrained and capable of being folded over one another, rolled up or possibly packaged; in more detail, each section is fixed with ropes or by means of handling belts, arranged laterally in substantial correspondence with the lateral guides 3 and has a lower flap 7 of greater weight (for example by inserting a bar of metal material) suitable for assisting the complete relaxation of the section.

In use, when the door 1 opens, the electric motor 5 draws the belts (or ropes) which, winding on the roller 4, cause the sections 6 to fold, starting from the one closest to the ground, close to the section immediately upper with a constraint substantially constituted by a flap positioned between one section and another. Following the complete opening of the door, the electric motor 5 is stopped by means of sensors which count the number of revolutions carried out by the same or and / or in combination, for example, by means of limit switch sensors positioned in the upper part of the side guides 3.

In this case, therefore, it is not the screen 2 that is directly rewound onto the roller 4, but only the belts suitable for recalling it; screen 2 simply folds in on itself, section by section.

One of the problems that are often encountered during the door opening and closing operations derives from the fact that typically following the opening of the door 1, its closure is timed; that is, following the complete opening of the door, after a predetermined time, a control system 9, electrically connected to the electric motor 5 through a cable 9a, activates the electric motor 5 again, this time in the opposite direction to that opening, to close the door.

Precisely for this reason, photocells 8 are typically introduced, positioned in an area close to the ground in correspondence with a lower part 3a of the side guides 3, which allow to identify any obstacles and, by sending a signal to the control system, reverse the motion of the electric motor or stop it.

These systems do not obviate the drawback of the fact that obstacles can often present themselves at a very high height compared to that coinciding with the ground; for example, in fact, the forks of a lift truck can have a height of up to one or more meters from the ground and cannot be identified by traditional photocells. Consequently, in this case the door would impact on them during the descent and, clearly, this is not admissible for operational safety reasons.

Precisely for this reason, photoelectric sensors such as the one shown in EP0875655 were used, positioned in the lower edge of the screen, which moving with it can detect the position of an object distanced from the ground, in a timely manner such as to cancel the impact force on the screen. obstacle or, at least, reduce it to a harmless level by at least stopping the electric motor immediately.

In any case, the solution shown in EP0875655 has some disadvantages.

In the first place, in order for the photocell to be rotated when the door is completely closed, it is necessary to provide for the affixing of deviation means (called deflectors) to the bottom of the opening in which the door itself is mounted.

Secondly, it must be considered that the distance at which the photocell is mounted from the edge of the screen must be proportional to the descent speed of the screen itself. In fact, the higher the descent speed, the greater the time lapse between the moment in which an obstacle is detected and the moment in which, finally, the motor and therefore the screen are completely stopped.

The presence of a rigid bar arranged and fixed in an immovable way in the lower part of the screen to which the flexible support of the photocell is bound forces a redesign or alternatively to a costly post-sale modification of the screen following any variation of the motor speed electric.

Finally, to ensure a complete closure and an impediment to the transverse flapping of the door in case of strong wind, the solution proposed by the above document once again requires a careful calculation of the distance between the position of the lower edge of the screen and the bar. rigid and having sliding guides of slightly larger size than the cross section of the weighting bar arranged at the bottom of the screen itself.

In addition, too much prominence of the lower edge of the screen beyond the weight bar would interfere with the ground mounted deflectors.

Finally, the flexible support of the photocell is subject to the risk of breakage, for example due to fatigue.

The purpose of the present invention is to provide a safety device for vertical descent doors, which is free from the drawbacks described above.

According to the present invention, a safety device for vertical descent doors is realized as claimed in claim 1.

The invention will now be described with reference to the attached drawings, which illustrate a non-limiting example of embodiment, in which:

Figure 1 illustrates a front view of a vertical descent door of known type, equipped with a movement control system;

Figure 2 illustrates a front view of a vertical descent door equipped with a safety device according to the present invention;

Figure 3 illustrates a detail of part of the safety device according to the present invention;

Figure 4 illustrates a three-dimensional view of a part at the end of a vertical descent door equipped with the safety device according to the present invention;

Figure 5 illustrates a side section view of the vertical descent door and of the safety device mounted on it, along the line III-III of Figure 2;

Figure 6 illustrates a front view of the vertical descent door of Figure 2, arranged in a different position from that shown in Figure 2 and partially adjacent to the ground in detail;

Figure 7 illustrates a side sectional view of the vertical descent door and the relative associated safety device along the lines VII-VII of Figure 6;

Figure 8 illustrates a side sectional view of a limited enlarged area of Figure 7.

With reference to Figure 2, the number 10 indicates as a whole a safety device for vertical descent doors 20 with a folding screen 21; the screen 21 is made up of a plurality of sections 22 mutually constrained and able to be folded one over the other; in more detail, each section is fastened to two movement belts, arranged laterally in substantial correspondence with lateral guides 23 adapted to constrain the vertical descent door 20 on a vertical plane in a direction orthogonal to that on which the screen 21 lies and has a lower area 27 of greater weight (for example through the insertion of a bar of metal material) adapted to assist the complete extension of the screen 21 itself when unfolded.

The safety device 10 comprises at least one pair of photocells 11a, 11b, arranged substantially below a terminal edge of the screen 21, so as to be aligned when they do not touch a ground 100. The photocells 11a, 11b are mounted on a support 12 comprising:

- a tubular-type metal bar 13, extending longitudinally along the entire width of the screen 21 and which also extends inside the lateral guides 23 in such a way as to be constrained thereto;

- a pair of rigid-type â € œad Lâ € 14 elements (in metal, aluminum, or similar materials), fixed to the ends of the bar 13 by means of a coupling system or possibly welded.

The L-shaped elements 14 (Figure 3) comprise a first section 14a and a second section 14b of shorter length than the first section 14a, in which the second section 14b is substantially parallel to the bar 13 and is adapted not to extend towards the of the lateral guides 23, remaining substantially incorporated therein.

In fact, since the photocells 11a, 11b are contained in the second portions 14b of the pair of elements 14, these are in a retracted position and therefore protected from impact.

The bar 13 is free to slide within a pocket 24 (figure 4) made of the same material as the screen 20 positioned in the section 22 which is closest to the ground. The pocket 24 is made in such a way as to support the weight of the bar 13 and the pairs of L-shaped elements 14 and is for example simply sewn or heat-sealed to the section 22 of the screen 21 closest to the ground.

With reference to figures 2, 3, 5 it is possible to observe how, as long as the device 10 does not touch the ground 100, it remains positioned substantially vertically by gravity, since the weight of the second ends 14b of the elements 14 themselves directs the device 10 along the vertical. For the same reason, the bar 13 remains positioned in the lower edge of the pocket 24. Preferably, moreover, the device 10 is mounted on a screen 20 which slides on a transversely wide lateral guide 23, which therefore allows the screen 20 itself to have a partial capacity floating.

The device 10 also comprises a control system capable of moving one or more electric motors for operating the door 20.

When a command to lower the door 20 is sent, the screen 21 is deployed by means of a roller 25 for moving at least one pair of side belts (not shown) positioned in the upper part of the door 20, until a plurality of sensors (not shown) of a known type, for example limit switches or a revolution counter of the electric motor, do not stop the door 20 itself.

More in detail, the side belts are fixed to the section 22 closest to the ground 100, in an area substantially corresponding to the side ends of the section 22 arranged along the side guides 23.

If the photocells 11a, 11b do not detect any obstacles, in the terminal part of the stroke of the screen 21 they are disabled from operation; when the door 20 stops (see Figures 4 and 5), the device 20 partially re-enters the pocket and, when inclined, the first ends 14a of the elements 14 interlock transversely on the guides, orienting themselves in a direction substantially different from the vertical (Figs. 6, 7).

This characteristic rotation of the device makes it possible not to limit the width of the lateral guides 23 in the vertical plane orthogonal to that on which the screen 21 lies and, at the same time, allows the screen to be fixed to the lower end, in such a way as to prevent flapping in windy weather. Furthermore, the partial retraction of the device 10 inside the pocket 24 ensures that the last section 22 of the screen 21 comes into contact with the ground 100, so as to ensure the insulation of the air also in the lower area of the door.

With reference to Figure 3, it can be observed that the photocells 11a, 11b exploit the tubularity of the elements 14 and of the bar 13 to be fixed to them and, respectively, to allow the protection of a signal transmission cable 11c towards the control system, thus preventing the cable 11c from being trapped inside the guides or being subjected to the aggression of external agents.

If, on the other hand, an obstacle is detected, which interrupts the beam of the photocells 11a, 11b, a stop and / or motion reversal signal is sent by the control system to the electric motor and, consequently, either the screen 21 stops completely or it is first stopped and then completely rewound.

Alternatively, if the door 20 has lateral guides 23 of a smaller size, that is, such as to prevent the screen 21 from floating, then the device 10 simply fits vertically into the pocket 24, without rotating.

The advantages of the present invention are clear from the foregoing description. In detail, the safety device for vertical descent doors described above allows first of all to prevent the screen of the vertical descent door from hitting obstacles that interfere with it during the descent phase, in a simple and inexpensive way and without devices. mounted on the ground; the safety device described up to now is also able to act, by its constitution, also as a weight for the terminal part of the screen 21, thus helping its descent.

Furthermore, through the use of the safety device according to the present invention, no costly modification in the production of the screens has to be carried out; in fact it is sufficient to fold the last two sections of the screen on themselves to create the pocket 24 which can contain the bar 13.

At the end of the travel of the screen 21, the device rests on the ground 100 and automatically, locking itself in the side guides 23, prevents the screen 21 possibly collapsed from banging due to the wind and due to the width of the side guides 23 themselves. Precisely for this reason, the device can also be easily installed on vertical drop down doors already assembled, as it is sufficient to install the bar 13 instead of the traditional weight in the lower part of the screen and insert the L-shaped elements inside the side guides. 13 without introducing any fixing device to the ground.

Furthermore, the safety device according to the present invention makes it possible to considerably reduce the breaking loads following repeated impacts with the ground, since it is made up mostly of metallic material. The intrinsic robustness of the elements 14, which are precisely metal and tubular, also acts as a shelter for the photocell itself inserted therein, preventing or at least strongly limiting the risk of breakage with respect to devices of the flexible type.

Finally, if the speed of the motor is varied, a simple solution of the first end 14a of the elements 14 with an end of different length is sufficient to produce an increase in the distance between the photocells 11a, 11b and the lower edge of the screen 21 which allows to avoid a possible impact; this therefore makes the safety device according to the present invention extremely flexible in its use, and capable of adapting to even high changes (for example increases) in the speed of the roller rotation motor.

Some variants can be applied to the device described up to now. In detail, the photocells mounted on the L-shaped elements can also be coupled in a number of two or greater on each side, in such a way as to guarantee the numerical redundancy of the control of the presence of obstacles and prevent the device from failing in the event of a photocell failure. .

Finally, where it is indicated that the sections of the door are moved by belts, this feature must not be considered as limiting; therefore the device according to the present invention, although it has been described in a real form

Claims (6)

CLAIMS 1. Safety device (10) for vertical descent doors (20), suitable for installation on doors equipped with a screen (21) suitable for isolating at least one closed environment from the outside or from a second environment; said screen (21) being moved by at least one electric motor capable of unfolding and folding said screen (21) by means of a winding roller (23); said screen (21) being able to touch a ground when completely unwound and being also constrained in its ascent and descent movement by a plurality of lateral guides (23); the safety device (10) comprises at least a pair of photocells (11a, 11b), arranged substantially below a terminal edge of the screen (21), and suitable for detecting the presence of an obstacle distant from said ground (100) on which the said vertical descent door (20) rests; the said safety device (10) being characterized by being able to be installed in a pocket (24) of the said vertical descent door (20) in such a way as to be able to slide inside said pocket (24) when said screen ( 21) rests on said ground (100). 2. Safety device according to claim 1, wherein said photocells (11a, 11b) are mounted on a support (12) comprising: - a bar (13) of the tubular type, extending longitudinally along the entire width of the screen (21) and further extending inside the lateral guides (23) in such a way as to be constrained thereto; - a pair of rigid-type â € œad Lâ € (14) elements fixed to the ends of the bar (13) by means of a coupling system or possibly welded; wherein said bar (13) is positioned inside said pocket (24) of said screen (21). 3. Safety device according to claim 2, wherein said bar (13) is of the metal type and is adapted to act as a weight on the part of the screen (21) closest to said ground (100). 4. Safety device according to claim 1, further comprising a control system adapted to control the operation of said photocells (11a, 11b), and to interact with said motor; said control system by interrupting the motion of the motor (25) when the beam of said photocells (11a, 11b) is interrupted. 5. Safety device according to claim 4, wherein said control of the operation of said photocells (11a, 11b) is interrupted when said screen (21) reaches an area substantially coincident with said ground (100). 6. Safety device according to claim 2, wherein said L-shaped elements (14), when said screen (21) is in contact with said ground (100), are able to fit transversely inside said lateral guides (23), in such a way as to constrain said screen (21) along a vertical plane orthogonal to that on which the screen (21) lies.