Patent Description:
As it is known, especially in the aeronautical field, the seats reserved for passengers must meet, on one side, strict safety standards and, on the other side, the needs requiring a reduced weight but, in any case, they must provide even a certain level of performances, in particular in terms of comfort.

The reclining seats, the present invention relates to, include a backrest consisting of a backrest frame having a substantially parallelepiped shape and which is formed by bar elements which define the side profile and the headrest thereof, and which are joined to the fixed supporting frame in order to be able to be reclined and brought back in erected position. On the backrest frame a padded coating of flexible type is then mounted.

The backrest frame comprises vertical bar elements, in particular arranged at the side edge of the backrest, and each one thereof has a joint revolvingly connecting it to the fixed supporting frame, in order to be able to swing when the seat is tilted.

In order to recline the backrest, the user generally acts by sitting on the sitting portion and by resting the back to the backrest itself, by exerting a pressure thereon.

At the same time, he/she presses a button which deactivates a device locking the backrest, and exerts with his/her back a force backwards which opposes to an elastic force which tends to bring the backrest back in an erected position.

Then, one understands that, if greater pressures were exerted at or near a side edge with respect to the other one, or however asymmetrically, the backrest could twist, since the two vertical bar elements are stressed by forces different therebetween.

Moreover, in particular, if the sitting portion was of the sliding type, to guarantee more space between seats of a row with respect to those of another row arranged frontally, the backrest has to be configured in an erected position, as well as in determined flight phases, and in case even the sitting portion has to be translated in rear direction, since it is hinged to the backrest at a lower end thereof, that is at the lower ends of the vertical bar elements.

Therefore, the reclining backrest is often tilted in one direction or in another one by its user.

However, the force exerted by the user body on the sitting portion could not always be symmetrical, and this can involve a backrest torsion.

This torsion, on one side, would tend to lock the rotation of the joints between backrest and frame and, on the other side, would involve an unwished wear of the reclining seat, and in any case the passenger would perceive less comfort.

International patent application No. <CIT> describes an aeronautical seat with reclining backrest, provided with a stiffening mechanism comprising an actuator arranged below the sitting portion, and acting on the frame ends of the backrest; but such mechanism has an overall dimension and weight which could result to be excessive in the transport field.

The technical problem underlying the present invention is to provide a reclining seat allowing to obviate the drawback mentioned with reference to the known art.

Such problem is solved by a seat as specified in the preamble, further comprising a stiffening mechanism which is integral with the fixed supporting frame and which provides, at each lower end of the vertical frame elements of the backrest, a lever, which is joined to a respective lower end and which forms a rocker arm thanks to a pin, thereon it is revolvingly mounted, integral with the fixed frame of the seat, so that each rocker arm rotates by an angle having a prefixed width, from a first position, corresponding to the reclining backrest in erected position, to a second position corresponding to the reclining backrest in reclined position.

The stiffening mechanism then comprises a stiff tie-rod, the tie-rod ends thereof are joined to the respective distal ends of the rocker arms, thereby the rotation of one of them causes the rotation of the other rocker arm by an angle having the same width.

This connection makes that the frame lower ends of the above-mentioned vertical bar elements always move synchronously, even if the backrest is stressed asymmetrically, since the above-described mechanism determines a mutual dragging of the two ends, by preventing the backrest frame from being subjected to a torsion.

The main advantage of the seat according to the present invention lies in the fact of preventing effectively the torsion of the seat frame, when the seat itself is stressed in disordered and asymmetrical way by the passenger.

The present invention will be described hereinafter according to a preferred embodiment example, provided by way of example and not with limiting purposes, of a reclining seat of aeronautical type and with reference to the enclosed drawings wherein:.

With reference to <FIG>, a row of the reclining seats is shown in cross section, by highlighting a reclining seat of a first example of the present invention, designated as a whole with <NUM>. The row can include a variable number of reclining seats, or can consist of one single seat; the seats composing the row can be reclined independently from one another. Such row is arranged to be positioned in a series of subsequent rows, parallel to each other, each one forming a space, between itself and the row positioned frontally, which is used by the users to access the seats <NUM> and to raise therefrom.

This type of seat in particular is an aeronautical seat, installed on board aircrafts, but it is meant that the invention generally relates to any type of seat which can be installed on board any vehicle, such as trains or buses, or even in other contexts, such as stadiums, cinema halls, conference halls and so on.

Each reclining seat <NUM> comprises a reclining backrest <NUM> and a fixed supporting frame which, in the present example, is constrained to the aircraft floor.

In particular, the fixed supporting frame of each reclining seat <NUM> consists of a fastening structure <NUM> which is provided to connect all seats of a row to specific anchoring means <NUM> implemented in the aircraft's floor according to suitable safety standards. The fastening structure comprises rear uprights <NUM> and front uprights <NUM>, which have respective upper ends which are connected respectively by a first rear cross bar <NUM> and by second front cross bar <NUM>, both of them supported at a certain distance from the ground, to provide a supporting base to the reclining seat.

The two cross bars <NUM>, <NUM> are tubular, that is they are implemented by stiff tubular elements extending horizontally by anchoring all seats of the row at a prefixed height. In particular, the tubular elements have a cylindrical and smooth external surface.

At each seat <NUM>, the fastening structure <NUM> then comprises a pair of stiff connecting elements <NUM> which extend between the two cross bars <NUM>, <NUM>, by connecting them stiffly, and by delimiting a space in which the reclining seat <NUM> is contained.

In particular, the connecting elements <NUM> comprise respective frame stiff extensions <NUM> extending in substantially vertical, or slightly tilted, direction from the first cross bar <NUM>, by delimiting a space wherein the reclining backrest <NUM> of each seat is comprised.

The connecting elements <NUM>, with the frame stiff extensions <NUM>, and the cross-bar portions <NUM> and <NUM> comprised therebetween substantially constitute the fixed supporting frame of each reclining seat <NUM>.

Moreover, the reclining seat <NUM> comprises a sitting portion <NUM> resting on said cross bars; it has a front sitting edge <NUM> and a rear sitting end <NUM>.

The reclining backrest <NUM> has a backrest frame <NUM> having a substantially parallelepiped-like shape extending from a backrest lower end <NUM>, arranged below the sitting portion <NUM>, and a headrest <NUM>, such shape being defined by the backrest frame <NUM> whereon a coating <NUM> is mounted.

The backrest frame <NUM> in particular comprises two vertical frame elements <NUM>, which are arranged each one at a respective side edge of the backrest <NUM>, extending from said backrest lower end <NUM> to a junction element implementing said headrest <NUM>.

The two frame elements <NUM> are stiff and they have a slightly bent shape to form a resting intrados for a user's back. Each frame element <NUM> has a first joint <NUM>, arranged near the backrest lower end <NUM>, revolvingly connecting the backrest <NUM> to the respective frame stiff extensions <NUM>, that is to the supporting frame formed in the fastening structure <NUM>.

The frame elements <NUM> further comprise respective lower ends <NUM>, which result to be positioned below the sitting portion and which are movable from a first prefixed position, corresponding to the backrest <NUM> in erected position, to a second prefixed position, corresponding to the backrest <NUM> in position reclined by the maximum angle allowed by the geometry of the reclining mechanism which is not herein described, but which can be of any type and allows possible intermediate positions between the two above-mentioned ones.

Below the sitting portion <NUM>, the reclining seat <NUM> comprises a respective stiffening mechanism, designated as a whole with <NUM>, to stiffen the reclining backrest <NUM>, which is associated to the supporting frame of the seat <NUM>, that is to the fastening structure <NUM>, and in particular to the first cross bar <NUM>.

The stiffening mechanism <NUM> acts on the lower ends <NUM> of each one of the frame elements <NUM>, which comprise a respective second joint <NUM> connected to a corresponding control arm <NUM>.

The stiffening mechanism <NUM> comprises respective first collars <NUM> fastened in a prefixed position to the first bar <NUM>, near a respective lower end <NUM>; each first collar comprises a respective stiff and fixed arm <NUM>, extending horizontally an arm in direction of the second opposite bar <NUM>.

Hereinafter, what has been described with reference to one of said two lower ends <NUM> can also be described for the other one, the portions being referred to one of the two ends functionally specular to those referred to the other end.

Therefore, the stiffening mechanism <NUM> comprises a lever <NUM> which is joined to said frame lower end <NUM> through said control arm <NUM>, and which is revolvingly hinged with respect to the fixed supporting frame at a first pin <NUM> implementing a respective joint which, in this example, is arranged at the projecting end <NUM> of the above-mentioned arm <NUM>, so that such joint is at a prefixed distance from the first bar <NUM> of the frame.

The lever <NUM> forms a rocker arm <NUM> extending from said pin <NUM>, the lever <NUM> and the rocker arm <NUM> being stiffly integral with one another and thus forming a stiff connection, in particular being implemented in one single piece.

The first pin <NUM> thus implements a respective hinge defining a respective rotation axis A which crosses, with its projections, the space comprised between the two cross bars <NUM>, <NUM>, and it is arranged at a certain distance, imposed by the arm <NUM>, from the first rear cross bar <NUM>.

In this respect, the lever <NUM> has a first distal end <NUM> revolvingly connected to said second joint <NUM> of the control arm <NUM>, thus implementing a kinematic connection joined between frame element <NUM> of the backrest <NUM> and the stiffening mechanism <NUM>.

Because of this mechanism, the rocker arm <NUM> rotates by a prefixed angle from a first position, corresponding to the reclining backrest <NUM> in erected position, to a second position, corresponding to the reclining backrest <NUM> in reclined position.

This rotation has a prefixed rotation axis, the width thereof is determined by the translation of the control arms <NUM>, that is by the excursion of the lower ends <NUM> when the backrest is moved from an erected position to a reclined position, positions which will be determined by suitable stops.

It will be noted that the excursion in particular of the rocker arm <NUM> could be wider than the limited excursion of the lower end <NUM>, since such end is at a reduced distance from the joint <NUM> of the backrest frame <NUM>, and since the angular excursion of the reclining backrest <NUM> itself will be however reduced.

Each rocker arm <NUM> has a respective second distal end <NUM> comprising a second pin <NUM> of hinge, still with substantially vertical axis designated with B (<FIG>), that is parallel to the one defined by the first pin <NUM>.

Each second pin <NUM> is revolvingly connected to the end of a stiff tie-rod <NUM> connecting each rocker arm <NUM> to the other one, implemented by a stiff rod with a predetermined length so that the tie-rod <NUM> makes that the second distal ends <NUM> of the rocker arms <NUM> are always at the same distance.

Thanks to this mechanism, the rotation of one lever <NUM> and of the respective rocker arm <NUM> causes a rotation of the other lever <NUM> and of the other respective rocker arm <NUM>, and vice versa, by an angle having the same width, and in this way the frame elements <NUM> of the backrest frame <NUM> move always synchronously, without determining any torsion in the backrest frame <NUM>.

With reference to <FIG>, it will be noted that the first rotation axis A, determined by the first pin <NUM>, the second rotation axis B, determined by the second pin <NUM>, and a third rotation axis C determined by the hinge connection between control arm <NUM> and lever <NUM>, are all parallel therebetween, and substantially vertical, whereas the first lever axes D identified by the levers <NUM> and the second lever axes E identified by the rocker arms <NUM> form equal angles therebetween, but facing opposite directions, and they move on a common plane, which is perpendicular to the rotation axes A, B, C.

In this example of stiffening mechanism <NUM>, the first pins <NUM> will be positioned thereby they will rotate one in counterclockwise direction and the other one in clockwise direction, and vice versa.

With reference to <FIG> and <FIG>, the stiffening mechanism <NUM> comprises a damping device <NUM>, performing the function of adjusting and slowing down the shifting of the seat <NUM> from a configuration to the other one.

This device <NUM> comprises a hydraulic cylinder <NUM>, acting as damper, which is conveniently connected to one of the levers <NUM>, in particular to its rocker arm <NUM>, whereas the other one has to be associated to a fixed portion of the supporting frame.

It is meant that more than one damper can be provided, connected to levers which rotate by accompanying the motion of the frame lower ends <NUM> of the backrest <NUM>.

In this example, the other end of the hydraulic cylinder <NUM> is connected to a second collar <NUM>, independent from the collars <NUM> and generally from the stiffening mechanism <NUM>, fastened to the first bar <NUM>, acting as tightening ring, and which can be positioned in any point of the fixed supporting frame along the first bar <NUM>, or in case even to the other one, to adapt its position to the features of the hydraulic cylinder <NUM>, by anchoring it fixedly, but even removably.

The tightening ring-like structure, acting on the tubular periphery of one of the cross bars <NUM>, <NUM>, can relate even to the above-described first collars <NUM>.

The arrangement in which all tightening rings are anchored to the rear cross bar <NUM> allows to empty the space below the sitting portion <NUM>, since both the stiffening mechanism <NUM> and the damping device <NUM> are associated on the rear side of the space below the sitting portion <NUM>, by making it more accessible to arrange luggage and accessories, thus reducing the overall space engaged by the stiffening mechanism <NUM>.

With reference to <FIG>, in a second embodiment example of the present seat, the two frame elements <NUM> have a cross connection bar <NUM> connecting them stiffly near the frame lower ends <NUM>. This connection can attenuate the torsion thereto the backrest frame <NUM> could be subjected, thus reducing the load on the tie-rod <NUM>, however it does not remove it.

Moreover, in the damping device <NUM>, which for the rest is equal to the one described previously, the hydraulic cylinder <NUM> of the damping device <NUM>, instead of being connected to the second collar <NUM>, is always connected to a section of the first cross bar <NUM>, at a distance from the frame lower end <NUM> whereon it acts so as to allow to insert the hydraulic cylinder <NUM>.

In this way, the hydraulic cylinder <NUM>, which in this example is mounted upside down with respect to the preceding example, can have a larger extension.

With reference to <FIG>, a third example of reclining seat <NUM> comprises both the stiffening mechanism <NUM> and the damping device <NUM> as they have been described with reference to <FIG> and <FIG>, wherein the sitting portion <NUM> is fixed and does not participate in the swinging motion of the reclining backrest <NUM>.

In the third example, the seat <NUM>, below the sitting portion, comprises a sliding system <NUM> of the sitting portion <NUM> which, as it will result clearly hereinafter, is integral with the fixed supporting frame of the reclining seat <NUM>; it comprises, at both two control levers <NUM>, respective first supporting slides <NUM> fastened in a prefixed position on the rear cross bar <NUM>. On each first supporting slide <NUM> a first, raised, rectilinear guide <NUM> is formed of the type with a through groove adapted to be engaged by a sliding pin.

The first supporting slide <NUM> could be formed on the above-described first collar <NUM>, or it could be connected directly on the first cross bar <NUM>.

On each first supporting slide <NUM> there is a first shoe <NUM> which is integral with the second joint <NUM> and with the control lever <NUM>; it has a respective upper face <NUM> which is provided with a plurality of fastening projections <NUM>, inserted in corresponding recesses formed on the surface of the sitting portion <NUM> which is rested upon such upper face, so as to create a stable connection.

The first shoes <NUM> are integral with the respective control levers <NUM> and second joints <NUM>, and each one has inside thereof a sliding pin inserted in said through groove.

On the second front cross bar <NUM>, in a position which substantially corresponds to the one of the first supporting slides <NUM>, the sliding system <NUM> provides respective second supporting slides <NUM> fastened in a prefixed position on the front cross bar <NUM>, and arranged however so as to project in the space between the two cross bars <NUM>, <NUM>. On each second supporting slide <NUM> a raised wall <NUM> is formed, formed vertically on one side of the second supporting slide <NUM>, therefrom a sliding pin projects.

The second supporting slide <NUM> could be connected directly on the second cross bar <NUM> by means of a fastening screw.

On each second supporting slide <NUM> there is a second shoe <NUM> having, like the first shoe <NUM>, a respective upper face <NUM> which is provided with a plurality of fastening projections <NUM>, inserted in corresponding recesses formed on the surface of the sitting portion <NUM> which is rested upon such upper face, so as to create a stable connection.

The second shoe <NUM> further has its own second, raised, rectilinear guide <NUM> of the type with a through groove adapted to be engaged by the sliding pin of the second supporting slide <NUM>.

The first and second guides <NUM>, <NUM> are parallel therebetween, and determine a prefixed course of the sitting portion <NUM> which, since it is fastened to said shoes <NUM>, <NUM>, can move back and forth for a limited excursion corresponding to the angular excursion of the backrest lower end <NUM> when the backrest <NUM> is reclined and is brought back in erected position.

In this third example, the rear sitting end <NUM> of the sitting portion <NUM> and revolvingly connected to the reclining backrest <NUM> near the backrest lower end <NUM>, that is below the first joint <NUM>, at a contact point between backrest <NUM> and sitting portion <NUM> designated with <NUM> in <FIG>.

Thanks to such connection, when the backrest <NUM> is reclined, its lower end <NUM> moves forwards and thus the sitting portion <NUM> and its sitting end <NUM>, whereas, when the backrest <NUM> is brought back in an erected position, the sitting portion <NUM> and its sitting end <NUM> move back.

In the present example, even this motion is dampened by the damping device <NUM>.

It is meant that, in this example of seat <NUM>, the passenger could recline the backrest <NUM> by exerting a pressure also or only on the sitting portion <NUM>, which could not be symmetrical and cause potentially a torsion onto the backrest as well as a rotation of the sitting portion <NUM>. However, these motions are prevented by the stiffening mechanism <NUM> acting also on the sitting portion, and by the fact that the sitting portion moves on rectilinear guides.

In the above-described examples, the hydraulic cylinder <NUM> could be of the elastic return type; in particular it could include inside thereof a spring arranged to make the hydraulic cylinder <NUM>, in absence of stresses onto the backrest, to go back from an extended configuration, corresponding to the reclined seat, to a retracted configuration, corresponding to the seat in erected position, or vice versa.

Otherwise, the elastic return of the seat in erected position, when it is released in absence of other stresses, by other elastic elements, in particular acting on the joints <NUM> of the backrest frame <NUM>.

Another solution may provide that a return elastic element is inserted in the pin(s) <NUM> of the vertical-axis hinge associated to the damping device <NUM>.

Claim 1:
A reclining seat (<NUM>) comprising:
• a fixed supporting frame;
• a sitting portion (<NUM>);
• a reclining backrest (<NUM>) having a backrest frame (<NUM>) with two vertical frame elements (<NUM>), arranged each one at a respective side edge of the reclining backrest (<NUM>), and each one thereof is provided with a joint (<NUM>), revolvingly connecting it to the fixed supporting frame, and a lower end (<NUM>) movable between positions depending upon the erected or reclined state of the backrest (<NUM>);
• a stiffening mechanism (<NUM>) comprising, at each lower end (<NUM>), a respective lever (<NUM>) hinged thereto, which can rotate around an axis (A) implemented by a pin (<NUM>) forming a respective hinge integral with the fixed supporting frame, and implementing a rocker arm (<NUM>), projecting from said hinge, which rotates by a prefixed angle from a first position, corresponding to the reclining backrest (<NUM>) in erected position, to a second position, corresponding to the reclining backrest (<NUM>) in reclined position,
wherein each rocker arm (<NUM>) has a respective distal end (<NUM>), a stiff tie-rod (<NUM>) being provided joined to the respective distal ends (<NUM>) of the rocker arms (<NUM>), thereby the rotation of one of the rocker arms (<NUM>) causes the rotation by an angle having the same width of the other rocker arm (<NUM>).