Patent Description:
This invention finds application, though not exclusively, in an aircraft door.

Reference will be made to this application below by way of example, though it is clear that the door of the invention may be applied to any vehicle type and, more generally, to any application that, for safety reasons, requires control, including remote control, of the correct closing of a mechanism.

Vehicle doors are configured to assume, as known, a first operating condition, closed, in which they isolate an environment of the aircraft from the outside environment, and a second operating condition, open, in which they allow passage between the environment of the aircraft and the outside environment.

One example of these doors may be provided by the doors of helicopters or of fixed-wing aircraft, both before performing flight operations and during the latter, for operating reasons (merely by way of example, for parachuting).

Referring to <FIG>, this illustrates an example of a door <NUM>' according to the prior art, which can be closed on a frame <NUM>' of an aircraft via a closing system. The latter comprises a mechanical transmission <NUM>' that can be manually driven by a lever <NUM>' to control at least one anchoring element <NUM>' defining an end that is sized to be inserted in or removed from a seat carried fixed by the frame <NUM>' so as to lock or unlock the door <NUM>' in relation to it. The user, by moving the lever <NUM>', controls the movement of the anchoring element <NUM>' and, thus, the locking / unlocking of the door <NUM>'.

According to regulations, it is necessary to provide visual means <NUM>' designed to enable the direct visualisation of the correct positioning of the anchoring element <NUM>' in relation to the door <NUM>', i.e., to the frame <NUM>'. In particular, these visual means <NUM>' are merely made via an opening <NUM>' wherein a highlighted portion <NUM>', otherwise known as a "flag", of the anchoring element <NUM>' can be visualised.

It is clear, in any case, that the user must move to see in each opening <NUM>' that the respective highlighted portion <NUM>' is in the correct position. In addition, it is clear that this visualisation may be imprecise and difficult according to the light conditions inside the aircraft.

There is, therefore, a need to provide a door enabling the visualisation of the correct closure or opening thereof that is simple, inexpensive, and easy to use.

An additional, known example is described in <CIT> that illustrates a fibre optics system for checking the correct closure of an aircraft door. This system comprises an optical indicator provided with an intermediate element <NUM> rigidly coupled to the locking mechanism so that the rotation of the mechanism corresponds to the rotation of the intermediate element; and an interruption <NUM> inside of the fibre optics system <NUM>, <NUM> designed to receive the intermediate element <NUM>. Specifically, when the intermediate element is housed inside the interruption <NUM>, the light transmitted through the fibre optics system <NUM>, <NUM> is altered; when the intermediate element is positioned outside the interruption <NUM>, the light travels freely through the fibre optics system.

Clearly, the presence of the intermediate element <NUM> increases the possibility of accumulating dirt with consequent malfunctions in the system. In addition, the element <NUM> may break or malfunction so that it can no longer alternate the light in the fibre optics system, signalling the incorrect closure of the door.

Other known prior art documents are <CIT> and <CIT>.

The purpose of this invention is to meet the needs outlined above in an optimal and inexpensive way.

The above-mentioned purpose is achieved with a door comprising a safety system as claimed in the attached independent claims.

Additional, preferred embodiments of the invention are constructed according to the dependent claims or those connected to the independent claims mentioned above.

To better understand this invention a preferred embodiment is described below, by way of non-limiting example and with reference to the attached drawings, in which:.

<FIG> illustrates a door <NUM> for an aircraft configured to be selectively fixed to a frame <NUM> of the aircraft so as to assume a first operating condition wherein the door <NUM> is open, i.e., not fixed to the frame <NUM>, and a second operating condition wherein the door <NUM> is closed, i.e., fixed to the frame <NUM>.

The door <NUM> comprises, thus, a closing system equipped with actuator means <NUM> and a mechanical transmission <NUM> configured to enable the passage from the first to the second operating condition. In particular, the actuator means <NUM> comprise a handle <NUM> connected to the mechanical transmission <NUM>.

In particular, the mechanical transmission <NUM> may be of any type for transmitting motion from the handle <NUM> to one or more anchoring elements <NUM> of the closing system.

In particular, each anchoring element <NUM> may comprise a rod <NUM> movably carried by the door <NUM> and equipped with an end portion <NUM> configured to assume a first condition in which it does not cooperate in contact with a seat carried integrally to the frame <NUM>, leaving the door <NUM> free to move, and a second condition in which it does cooperate in contact with this seat, thus creating a mechanical coupling to lock the door <NUM>.

In particular, the mechanical transmission <NUM> and the at least one anchoring element <NUM> are housed inside a space <NUM> delimited by walls 1a defining the door <NUM>.

According to the invention, the door <NUM> is provided with a safety system <NUM> configured to detect the correct position of the at least one anchoring element <NUM>, i.e., to detect the locking/unlocking of the door <NUM>, in particular, in the example described, of the insertion of the end portion <NUM> into the related seat.

Referring to <FIG>, the safety system <NUM> comprises optical detection means <NUM> configured to emit a signal as a function of the position of the anchoring element <NUM>.

In particular, these optical detection means <NUM> comprise a source <NUM> of light radiation, for example an LED (Light Emitting Diode), and a receptor element <NUM> for light radiation arranged so as to detect electromagnetic radiation emitted by the source <NUM> as a function of the position of the anchoring element <NUM>. Clearly, the source <NUM> is connected to an electrical power source that, supplying voltage/current to the latter, enables the continuous emission of light radiation.

More specifically, the safety system <NUM> comprises a shielding element <NUM> rigidly carried by the anchoring element <NUM>, for example made like a flange <NUM>, extending from a sleeve fixed to the rod <NUM>. This shielding element <NUM> defines a through opening <NUM>, which enables the passage of light radiation between the source <NUM> and the receptor <NUM>. In particular, the opening <NUM> does not house any element inside, enabling the free passage of the light radiation towards the receptor element <NUM> through it.

According to the embodiment described, the source <NUM>, i.e., the LED element, is carried by a support element fixed in relation to the wall 1a of the door <NUM> and is turned so that it faces the flange <NUM>. The movement of the flange <NUM>, carried by the anchoring element <NUM> occludes, or fails to occlude, the passage of the light source through the opening <NUM> between the source <NUM> and the receptor <NUM>.

The receptor <NUM> is connected to signalling means <NUM> configured to signal to the user if enough light radiation provided by the source <NUM> is detected. These signalling means <NUM> are preferably optically connected to said receptor and comprise a warning light <NUM>. Clearly, the warning light <NUM> may be any colour or shape, depending on the type of vehicle.

In particular, the receptor <NUM> comprises an optical fibre <NUM>, a first end 19a thereof is housed facing the light source <NUM>, carried by the support element fixed to the wall 1a and a second end 19b is connected to the signalling means <NUM> and forms the above-mentioned warning light <NUM>.

Advantageously, a safety system <NUM> is provided for each of the anchoring elements <NUM> and each of these is advantageously housed inside the space <NUM>.

As illustrated in <FIG>, preferably each signalling means <NUM> is integrated into a single signalling device <NUM> comprising as many warning lights <NUM> as there are safety systems <NUM>. This signalling device <NUM> preferably comprises a jig <NUM> defining multiple holes each housing a warning light <NUM>.

More preferably, this jig <NUM> is housed near the actuator means <NUM> or in any other position of the door <NUM> which can be seen by a user. Obviously, the signalling means <NUM> may be arranged in other parts of the vehicle, for example in a driving cab or cockpit.

The operation of the embodiment of the door <NUM> comprising a safety system according to the invention described above is the following.

Imagining that the door <NUM> is in an open operating condition, the user moves the handle <NUM> so that, thanks to the transmission <NUM>, the anchoring means <NUM> fix the door <NUM> to the frame <NUM>. In this condition, the plate <NUM> covers the light source <NUM> and, thus, the optical fibre <NUM> end 19a does not detect enough light to illuminate the warning light <NUM> placed in the jig <NUM> adjacent to the handle <NUM>. When the rod <NUM> is placed in the correct position, the light source <NUM> faces the opening <NUM> and the end 19a of the optical fibre <NUM>. The latter thus receives enough light to illuminate the warning light <NUM>.

The user may, thus, easily, visually control the correct positioning of each rod and understand whether there has been a breakage in the transmission <NUM> affecting the correct closure of the door <NUM>.

The operation is similar in the opposite case, from closure to opening, and the switching off of each light guarantees the disengagement of the door <NUM> in relation to the frame <NUM>.

From the above, the advantages of a door equipped with a safety system according to the invention are clear.

Thanks to the safety system proposed, it is possible to easily and quickly check the correct closure of the vehicle door. In particular, the system described is extremely simple, uses few elements, and, thus, has a working life that is virtually unlimited.

In particular, it is possible to visually check, in just one glance, the positioning of each anchoring element.

In addition, the use of a light source and optical fibre makes it possible to provide a system that complies with the aeronautics sector regulations regarding door closing systems.

In particular, the system proposed is very reliable, low-consumption, and easy and inexpensive to maintain. In particular, there is no possibility of malfunctioning since the signalling means would not signal light, neither in the case of a mechanical malfunction, nor in the case of a light source <NUM> malfunction. In particular, compared to the system <CIT>, the system is simpler and more reliable thanks to the absence of the intermediate element illustrated here.

In addition, the system according to the invention may be used in environments containing explosive mixtures since the use of electrical power is limited and the transmission in the door is basically optical.

Finally, it is clear that changes and variations may be made to the door equipped with the safety system according to this invention that, in any case, do not depart from the scope of protection defined by the claims.

Clearly, it is possible that the closing system is made in a different way, i.e., that the mechanical transmission <NUM> comprises elements other than those described, or that the anchoring element <NUM> is present in different numbers, shapes, and types.

Similarly, the safety system <NUM> may comprise different light sources <NUM>, receptors <NUM>, and signalling means <NUM>.

Claim 1:
A door (<NUM>) configured to be selectively closed and fixed on a frame (<NUM>),
said door (<NUM>) comprising a closing system equipped with actuator means (<NUM>), at least one anchoring element (<NUM>) and a mechanical transmission (<NUM>), said actuator means (<NUM>) being configured to move said at least one anchoring element (<NUM>) between a first operative condition in which they do not cooperate with said frame (<NUM>), leaving said door (<NUM>) free to move with respect to it, and a second operative condition in which they cooperate with said frame (<NUM>) to fix said door (<NUM>) to the latter,
said door (<NUM>) comprising a safety system (<NUM>) for said at least one anchoring element (<NUM>), said safety system (<NUM>) comprising a source (<NUM>) of light radiations and a receptor (<NUM>) of said radiations, said source (<NUM>) being integral with one of said door (<NUM>) and said anchoring element (<NUM>) said receptor (<NUM>) being integral with said one of said anchoring element (<NUM>) and said door (<NUM>), said receptor (<NUM>) being optically connected to signalling means (<NUM>), said signalling means (<NUM>) signalling the positioning of said anchoring element (<NUM>) in said second operating condition when said receiver (<NUM>) receives said light radiation from said source (<NUM>),
wherein said safety system (<NUM>) comprises a shielding element (<NUM>), said shielding element (<NUM>) being integral with the other between said anchoring element (<NUM>) and said door (<NUM>), said shielding element (<NUM>) preventing the passage of light radiation between said source (<NUM>) and said receptor (<NUM>) when said anchoring element (<NUM>) is in said first operating condition and allowing the passage of light radiation when said anchoring element (<NUM>) is in said second operating condition, wherein said shielding element (<NUM>) comprises a flange (<NUM>) integral with said other between said door (<NUM>) and said anchoring element (<NUM>),
characterized in that flange (<NUM>) being provided with a through hole (<NUM>) configured to enable the unaltered passage of said light radiation.