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Title:
BUCKET SEAT
Document Type and Number:
WIPO Patent Application WO/2017/137960
Kind Code:
A1
Abstract:
A bucket seat that has a backrest (1) with an outer boundary on a XZ plane shaped as an arc of a circle and reclines moving the outer boundary along the same circle such that, upon reclining no element of the seat intrude in the space behind the outer boundary. A bucket seat that has a backrest (1) with an outer boundary on a XY plane with a convex shape and has a armrest cooperating with the seat pan (91), to improve the knee space of the passenger behind. A bucket seat that has a base frame which does not intrude in the knee space of the passenger behind.

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Inventors:
ZAHIROVIC EMIR (DK)
CENNI ROBERTA (DK)
Application Number:
PCT/IB2017/050779
Publication Date:
August 17, 2017
Filing Date:
February 13, 2017
Export Citation:
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Assignee:
IDEABANK APS (DK)
International Classes:
A47C1/028
Domestic Patent References:
WO2011060234A12011-05-19
Foreign References:
FR2058867A51971-05-28
GB2402612A2004-12-15
DE1099142B1961-02-09
US5553923A1996-09-10
EP1600375B12008-10-01
US20150151652A12015-06-04
US20100308175A12010-12-09
US20120139302A12012-06-07
US20030011227A12003-01-16
US4007960A1977-02-15
CA2669053A12009-12-19
US4911381A1990-03-27
US5152578A1992-10-06
US20040100137A12004-05-27
Attorney, Agent or Firm:
ROMANO, Giuseppe et al. (IT)
Download PDF:
Claims:
CLAIMS

1. A seat comprising a backrest, a seat pan and a reclining mechanism, said backrest, seat pan and reclining mechanism cooperating with each other to form a reclining seat having a section on a XZ coordinate system with an X axis and a Z axis, wherein the seat cooperates with a floor, wherein the Z axis is orthogonal to said floor, has a zero point on the floor, has a positive direction from the floor to the seat and it is tangential to the backrest and wherein the X is parallel to said floor has a zero point at an intersection with the Z axis and has a positive direction from the backrest to the seat pan, wherein the backrest has an XZ outermost boundary, being formed by a plurality of points of the backrest having the lowest value of the axis X for a value of the axis Z, said

XZ outermost boundary being formed as an arc of a circle with a center 10, located on the XZ coordinate system and having a positive X value; wherein the seat has a reclining position in the XZ coordinate system defined by an angle formed between a line, which is tangent to said XZ outermost boundary at a point

P, and a line, which is parallel to axis X passing through point P, in the XZ coordinate system, wherein the XZ outermost boundary of the seat in at least two reclining positions are arcs of said circle with said center 10.

2. A seat as in claim 1 , wherein all points of the XZ outermost boundary of the backrest form an arc of a circle with center in 10 located on the XZ coordinate system; 3. A rotation device comprising a guide and a sliding body, wherein on an XZ coordinate system, a section of the guide and a section of the sliding body are shaped as arcs of concentric circles, with a center C; and wherein the guide and the sliding body slide relative to each other, said sliding being a rotary motion on the XZ coordinate system around said center C;

4. A rotation device as in claim 3 comprising a spring, said spring being coiled as a section of a toroid, said toroid having a center coinciding with center C on the XZ coordinate system, wherein said spring cooperates both with the sliding body and the guide;

5. A seat as in claim 1 or 2 wherein said reclining mechanism comprises a rotation device as in claims 3 or 4, wherein said center C of the rotation device corresponds to center 10 of the XZ outermost boundary in the XZ coordinate system as described in claim 1 , and wherein one of either the sliding body or the guide cooperates with a base frame, which cooperates with the floor, and wherein the other of either the sliding body or the guide cooperates with the backrest and/or the seat pan of said seat;

6. A seat comprising a backrest and a seat pan defined in a XYZ coordinate system with an X axis, a Y axis, and a Z axis, wherein the seat cooperates with a floor, wherein the Z axis is orthogonal to said floor, has a zero point on the floor, has a positive direction from the floor to the seat and it is tangential to the backrest, wherein the X axis is parallel to said floor has a zero point at an intersection with the Z axis and has a positive direction from the backrest to the seat pan, and wherein the Y axis has a zero point at the intersection of the X and the Z axis and is orthogonal to the X and the Z axes, wherein the backrest has an XY outermost boundary, being formed by points of the backrest having the lowest value of the axis X for a value of the axis Y, said XY outermost boundary being concave towards the direction of increasing X;

7. A seat as in claim 6, wherein the XY outermost boundary of the backrest is concave

towards the direction of increasing X for any value of Z;

8. A seat as in any or all of claims 1 , 2, 5, 6, and 7;

9. A base frame for a seat comprising a plurality of spreaders, a stretcher tube, and a connecting device said spreaders and said connecting device cooperating with a stretcher tube, wherein a spreader comprises a spreader passage, said spreader passage having a shape wherein a stretcher tube fits; wherein the connecting device comprises a connecting passage, said connecting pas- sage having a shape wherein a stretcher tube fits; wherein the connecting device cooperates with a seat holder, said seat holder being a part of a seat; wherein a spreader comprises a floor connection;

10. A spreader as in claim 9, wherein said floor connection is a track fitting, said track fitting cooperating with a rail or a track, comprising an aircraft seating track; 1 1. A spreader as in claims 9 or 10, comprising three stretcher tubes;

12. A seat holder for a base frame as in any or all of claims 9-1 1 , wherein said seat holder cooperates with a seat as in claims 1 , 2, 5, 6, 7, or 8 13. A seat holder for a base frame as in any or all of claims 9-1 1 , wherein said seat holder is either a guide or a sliding body cooperating with the backrest and/or the seat pan of a seat as in claims 5, 6, 7, or 8

14. A base frame as in any or all of claims 9-13, and a seat as in any or all of claims 1 , 2, 5- 8 wherein a point on the spreader is located on a XY coordinate system within the convex curve formed by the XY outermost boundary of the backrest;

15. A base frame and a seat as in claim 14 wherein all points on the spreader are located on a XY coordinate system within the convex curve formed by the XY outermost boundary of the backrest;

16. A seat as in any or all of claims 1 , 2, 5-8, 14, 15 comprising a support system for an In- Flight Entertainment element, said support system having a profile on the XZ coordinate system being formed as an arc of a circle with center 10 in the XZ coordinate system, said support system cooperating with the one seat element, between the guide or the sliding body, which cooperates with the base frame;

17. A seat as in any or all of claims 1 , 2, 5-8, 14-16 comprising an armrest, said armrest cooperating with the one seat element, between the guide or the sliding body, which cooperates with the seat;

18. A seat as in any or all of claims 1 , 2, 5-8, 14-17 comprising an armrest, said armrest cooperating with said seat pan;

19. A seat as in any or all of claims 1 , 2, 5-8, 14-18 comprising a privacy canopy;

20. A seat as in any or all of of claims 1 , 2, 5-8, 14-19 used for passenger transport,

comprising airways, seaways, roadways transport; for entertainment in public and private, comprising but not limited to in theatres, cinemas, entertainment parks, home; for higher comfort in a plurality of public and private places where long sitting time may occur, comprising airports, stations, hospitals, medical and beauty clinics, home.

Description:
BUCKET SEAT

DESCRIPTION FIELD OF THE INVENTION

Seats are used in private, public and commercial applications, for example in the passenger transport industry, on sea, land or air, or in the entertainment industry, for example in cinemas and theaters. In some of these commercial activities, profitability is maximized by fitting more persons in the same space. A consequence of this is the reduction of the space destined to the individual seat occupant, which consequently reduces the level of comfort experienced by the occupant. In the following we will refer to the seat occupant often as the "passenger" since many of the problems that the present invention addressed are prevalent in seats in airplane cabins, without the intention to limit the applicability of this invention.

In seating rows arrangements, where seats face the back of the seat in front, like in most economy class seat maps, the legroom, defined by the seat pitch (the space between each seat anchor, between rows), the seat width and the recline are among important parameters to qualify comfort. In seating rows with narrow legroom, reclining a seat in front causes the backrest to intrude in the space of the rear occupant. Consequently, the rear occupant will not be able to enjoy the functionality of the tray in front, for example for eating or holding a laptop, and may even find himself/herself immobilized in the seat. Thus, as a recent trend, seats in the economy class tend to be made without any reclining functionality. Leaning back and adjusting the position of the legs with respect to the back may be critical to some in long-seating situations. For seat occupants suffering specific ailments, this functionality may affect a person's willingness to purchase a service requiring long seating times or the occurrence of medical events during the stay.

There is therefore the need of a seat, which allows the possibility to recline the backrest without intruding in the space behind.

A reclining seat, which does not intrude in the space behind is of interest even in private applications where the features of the bucket seat offer functional or aesthetic value. One additional application for these seats is in waiting rooms or areas, as for example in airports, train stations, medical clinics and hospitals, beauty centres, etc. In these areas, typically the seats are not free to recline, either because seats are positioned with the backrest close to the walls or with the backrest against each other. This is done to maximize the space for moving in the rooms, or because, even in an open space, reclining by means of systems known in the art, causes the seats to intrude in the space behind creating hurdles to the movement of other people. Still, as waiting time is often long, reclining is a desirable feature to release positional loads at spine, hips, legs, etc. At the narrow seat pitch, prevalent in economy class, large-sized passengers experience restrictions of even simple movements, for example with immobilization of their knees, even when the seat in front is not reclined. The base frame of aircraft seats, as known from the art, is typically made of at least two legs assembly, connected to the airplane floor tracks; two stretcher tubes, one front and one rear, mounted to the leg assemblies; and a number of spreaders, mounted to the stretcher tubes and sometimes to the leg assemblies, keeping the two stretcher tubes parallel to each other. A thorough description of a base frame of an aircraft seat is given for example in US5553923. The construction with two stretcher tubes and spreaders is still current, as for example shown in EP_1600375_B1. The leg assembly connects the seat to the floor tracks. The position of the tracks on the floor depends upon several factors, for example the standard of the aircraft manufacturer and the fuselage type (for example narrow vs. wide body). Also, the position of the leg assemblies with respect to the seat varies according to the position of the seat, for example close to the wall or close to an emergency exit. One of the constraints that leads to the construction of the base frame as it is known today is the need to incorporate flexibility as to the position of the leg assemblies, such that broad applicability is ensured.

In the base frames known from the art, the rectangle defined by two neighbouring spreaders and the segments of front and rear stretcher tubes enclosed between the two spreaders defines the position of one seat and offers the support for the seat bottom cushion assembly. The spreaders are shared among two contiguous seats so that the total number of spreaders in a seat rack is equal to the number of the seats plus one. The spreaders have further the function to support the armrests, the pivoting mechanism of the backrest recline, and the tray.

We noticed that the assembly given by the two stretcher tubes and the spreaders makes a bench-like construction that does not use optimally the space with respect to the passenger comfort. In facts, the bench-like construction with a rear bar (stretcher) creates a seat pan space which is often in excess of what the passenger sitting on the seat needs in correspondence of the hips. At the same time, the rear stretcher (bar) and the cooperating spreaders and armrests are positioned directly in front of the knees of tall passengers sitting behind, thus creating an impediment for the knees of the passenger behind, which are consequently immobilized. It is important to notice that the knees of taller passengers are taller than the armrests in front. Thus, we noticed that the problem cannot be solved by positioning the armrests simply in a higher position than today common in the art.

There is therefore the need of a seat which, either in straight or reclined position, allows the mobility of the knees of a rear occupant.

Seats fitting in tight arrangements cause further discomfort to passengers at the window or the middle seat. Reaching aisle from those seats require asking the passengers towards the aisle to exit the row. This has a psychological impact on some window / middle seat passengers, who may prefer to avoid inconveniencing other passengers and refrain from reaching the aisle, even in case of need. Demands on minimum evacuation time from the rows also put a limit to the lowest pitch. Albeit the passenger's size and weight may challenge the evacuation time, still many other conditions may affect it too: for example, age (children or old persons), medical conditions, or other. There is therefore the need of a seat that facilitate fast evacuation from the rows

In addition, tight seat arrangement causes discomfort to some because of the frequent eye contact with other passengers. There is therefore the need of a seat with improved privacy. In the transport industry, safety criteria for seats address on the one side the crashworthiness of the seat itself. These are aimed to ensure that, if a crash occurs, the seat does not deform such to entrap the passenger thus exposing him/her to injuries determined by a secondary event

(explosion or fires are often the secondary event following a crash). To avoid the consequences of these events, the passenger must be able to leave the aircraft as fast as possible after a crash. On the other side, the structural elements of the seat, the base frame performing the connection system of the seat with the floor, the upholstery, and the disposition of the seats in the cabin (for example the seat pitch) have to be such to minimize the injuries to the passenger upon a crash. Three critical areas are identified in this respect: the head, the femurs, and the spine.

The head and the femurs are particularly exposed to injuries upon a forward crash. Sudden deceleration in a forward crash propel the passenger's body violently forward. With most seats known in the art, the hips are held close to the seat by a 2-points safety belt, the head is swung forward (unless the passenger is already in brace position) and it may strike the back shell of the seat in front. Even if the passenger is in brace position, the forward load can be very high and tall passenger may hit the head and the knees violently against the seat in front. The back shell of seats known in the art is made of hard material in correspondence of the areas where the head and the knees of the passenger behind hit. The results of such violent strikes are frequently injuries at the head, the knees or the femurs.

Crash tests are typically used to ensure that the biomechanical load on a passenger, under the seating layout proposed for the aircraft, does not exceed critical loads on the body parts that are found to be the most exposed: head, knees, femurs. Crash tests are conducted with

Anthropomorphic Test Dummies (ATD) of standard size. Thus, seat layouts comprising seats as known in the art are designed to safeguard passengers of standard size. However, they do not ensure the safety, nor the comfort, of passengers of different sizes. There is therefore the need of a seat that safeguards the safety of passengers of non-standard size. With seats known in the art, the spine is critically affected for example when the aircraft hits the ground violently in a downward direction. This is an event that occurs at a certain frequency during take-off or landing. During such an event, the spine is solicited by strong vertical loads from the bottom and from the top. These vertical loads are a frequent cause of spine compression fractures. There is therefore the need of a seat offering minimal biomechanical load to all passengers, regardless of passengers' size.

BACKGROUND

US 2015/0151652 A1 discloses an aircraft seat, comprising a back rest and a seat pan forming a dihedron with each other with a constant angle. Furthermore, the seat comprises a head rest and is integral to a base. The seat reclines by rotating around a virtual axis. As the rear profile of the seat is a dihedron, when the seat is rotated, the distance between the rear part of the rotating seat and the base in which it is contained changes. Therefore, additional space has to be accommodated between the base and the rotating seat to allow reclining.

US 2010/0308175 A1 disclose a space vehicle seat comprising a rigid hull to be fit in a cylindrical space vehicle. The seat allows for a wide range of sliding and rotational movements such that the occupant may always be placed in the orientation perpendicular to the forces of acceleration. Also in this case, the rear profile of the seat is a polyhedron and space between the round wall of the space vehicle and the straight back of the seat has to be accounted for to permit the rotation of the seat.

US 2012/139302 A1 describes an airplane passenger seat which reclines by rotation. In this invention, the axis around which the seat rotates is located on the seat pan, approximately at the intersection between the seat pan and the back rest. By this rotating mechanism, reclination still causes the seat to intrude in the space behind. US 2003/011227 A1 describes a chair with reclinable seat having similar functionality.

US 4,007,960 describes a reclining elevator chair which may be tilted and raised simultaneously to assist a disabled person in leaving the chair.

CA 2669053 A1 discloses a reclinable wheel chair with adjustable parallel locking gas spring device. The chair is reclined by rotation with no intention to preserve the integrity of the space behind the chair, upon rotation.

Safety is one of the areas where seats are constantly developed, for example: US 4,911 ,381 and US 5, 152,578,

Improvements to a traditional construction of the base frame, as described in the previous chapter, are for example taught in US_2004_0100137_A1. Still, even with this one/beam construction, the spreader cooperating with the arm rest limits the space available for the knees of tall passengers sitting behind. WO_201 1_060234 A1 in Fig. 13 teaches a construction where the spreaders are removed. Still, the presence of the armrest cooperating with the table limits the advantages of the invention. SUMMARY OF THE INVENTION

The invention has several features that may constitute independent inventions and they may be applied individually or together.

Each feature has a specific objective, defined in the description pertaining the feature.

Throughout the text, expressions as "approximately" or "most of" and the like are intended to describe a deviation from the rigorous description, which still makes it possible to achieve the objective of the invention. For example, "approximately circular" defines a convex curve that, in a part of the curve, which is of interest for performing the invention, may be approximated by a circle. The approximation is acceptable, in the meaning of the invention, if in a section of the curve, which is of interest to perform the invention, and for a relevant coordinate of a

measurement system, the distance between a point of the circle and a point of the curve which approximates the circle is so small that replacing the circle by the approximating curve does not jeopardize achieving the objective of the invention. This is graphically explained in Figure 1. Throughout the text, we have described the invention mostly by means of 2-dimensional coordinate planes: either XZ, XY or YZ plane, whereas the three axes X, Y and Z are orthogonal with respect to each other.

Rotational movements in two dimensions in any XZ plane are around a point (the center of a circle). In a three-dimensional space including a dimension Y orthogonal to the XZ plane, the locus of all the points around which each point of the object rotate is an axis of constant X and Z positions. Throughout the text we have used the description "rotating around a center" when describing the invention in a 2-dimensional space and "rotating around the axis" when describing the invention in a 3-dimensional space. FEATURE 1 OF THE INVENTION: SHAPE OF THE BACKREST ON A XZ PLANE

The invention discloses a novel bucket seat, which fits in a narrow space and enables an occupant to recline the backrest, even with virtually no space behind the backrest. An important field of application of the seat is in interior design configurations with tight arrangement of seats. In such applications, the invention allows to place at least two seats in tightly arranged rows, where one faces the other's back, while ensuring to the occupant of the seat in front the possibility to recline the backrest without intruding in the space of the occupant of the seat behind.

The seat of the invention has a back section comprising a backrest. Said backrest can be moved by rotation. The backrest may comprise at least part of a reclination mechanism. The backrest has a rear side and a front side. On a XZ plane, the rear side of the backrest has an outer boundary curve, which in this document is called the XZ outer boundary. The XZ outer boundary may be a virtual or a physical curve enveloping the main part of the outermost points of the rear side of the backrest. A main part of the XZ outer boundary is approximately an arc of a circle (Figure 2) with a center (10).

The objective of this invention is to improve the comfort of occupants of seats in narrow spacing by allowing a non-disturbed and a non-disturbing reclination movement. The rear side of the seat of the invention is such that, on a XZ plane, a distance between a point of a still body behind the reclining seat and a point of the XZ outer boundary remains substantially the same or increases at any of the positions that the seat can assume (Figure 3).

The back section comprises further a trajectory of motion on an XZ plane (Figure 2). The trajectory of motion is convex, approximately an arc of a circle (5) of center (10). The backrest cooperates with a reclination mechanism. When the reclination mechanism is activated, the main part of the points on the XZ outer boundary rotates around (10) (Figure 2). More than one seat of this invention, each with a XZ outer boundary shaped along substantially the same circle, may be placed in a tight arrangement, wherein the front side of one seat faces the rear side of another seat, an arrangement typical, for example, of aircraft cabins. In this arrangement, reclining a seat of this invention does not change the distance between the occupant of a rear seat and the seat in front of said occupant. The invention thus enables any passenger of a front seat to freely recline the seat without intruding in the space of the occupant of the rear seat, even in arrangements with narrow legroom (Figure 3).

One embodiment of the invention is obtained with a reclination mechanism described as in FEATURE 3, describing a rotation device comprising a convex main part, shaped approximately as an arc of a circle with center (10).

In the context of the XZ outer boundary, the term "main part' is to be understood such that the main objective of the invention may be achieved. Thus, parts of the backrest, for example a pocket, may slightly protrude outside the main XZ outer boundary as long as the motion of this part does not cause excessive intrusion in the space behind. A quantitative definition of the geometry of such parts depends upon certain design parameters, comprising the degree of reclination of the seat, the height of the backrest, and the legroom, or the space available behind the backrest to be reclined.

Elements of the seat and the backrest that do not belong to the XZ outer boundary, should not be understood to necessarily follow the described rotational movement around (10), as they do not jeopardize the objective of the invention. Thus, for example a seat pan may recline independently of the rotational movement (Figure 4). If the backrest has a circular outer boundary in a plane XZ and rotates along that circle, the available space to one passenger is affected only by the passenger's own decision to recline his/her own seat, and thus it is under control of the passenger him/herself (see also Figure 5). If the backrest is designed according to common designs in the art, the space available for one passenger, is controlled by the decision of the passenger in front. With the seat of the invention, the tray of each seat is not cooperating with the rear part of the back rest, as it is known in the art today, but it is preferable cooperating with the seat itself, so that it can follow the passenger reclination choices (not shown here).

In most cases the circle (5), Figure 1 , is virtual. However, the invention may be performed with a physical circle (on a XZ plane), for example when the seats are used as interiors to a cylindrical body, where the seats are designed such to slide following the curve of the cylindrical body. The seat of this invention offers substantial flexibility to rotation, such that the seat may be rotated to tilt an occupant from an almost laying to a standing position (Figure 15). FEATURE 2 OF THE INVENTION: SHAPE OF THE BACKREST ON A XY PLANE

The invention discloses a novel bucket seat, which may be fit in a tight arrangement of seats. The seat offers higher spaciousness toward a seat behind in correspondence of a rear occupant's knees, such that the rear occupant experiences a higher level of comfort than with other seats described in the art. This invention may be used together with FEATURE 1 of the invention or independently.

The objective of this invention is to increase the knee room for occupants of seats in narrowly- spaced rows.

A bucket seat comprising a back rest with a rear side. On a XY plane, the backrest has an outer boundary curve, which in this document is called the XY outer boundary, enveloping the outermost points of the rear side of the backrest.

A main part of the XY outer boundary is convex (Figure 5), the convex curve being smooth or with corners. Figure 5 shows an embodiment of the invention with occupants. The seat shown in this drawing is the seat according to FEATURE 1 which reclines by rotation (part A). Part B and part C of Figure 5 show sections on the XZ plane of two levels at the Z axis: Z1 , just above the knee height and Z2, above the head of the occupant. Figure 5 shows that by means of the seat with a convex outer boundary of this FEATURE 2, the occupant of a seat has significant knee room in either reclined or straight position. Notice that in Figure 5, the middle occupant, in reclined position, seems to have the knee protruding into the backrest of the seat in front (Part A). However, as shown in Part B, the knees may easily be brought into a position where they do not touch the backrest of the occupant in front.

Embodiments of this invention are shown in Figure 6. In the context of this invention, the "main part" of the XY outer boundary has to be intended as the part that allows the invention's objective to be achieved. Thus, The XY outer boundary shall be convex in correspondence of the height of the backseat that faces the knees of the occupant of the rear seat, when both seats are straight, when both seats are reclined and when one of the two seats is straight and the other reclined. Thus, to achieve the objective of the invention, it may not be necessary that the upper part of the backseat is convex, if the seat is meant to achieve only moderate reclination levels. Figure 7 shows some embodiments that can fulfil the objective of the invention. The upper part of the backrest does not need to be convex, as the knees of an occupant may not reasonably be found there. Embodiment C shows a backrest with convex bottom and straight top.

In order to achieve the objective of this FEATURE 2, not only the shape of the backrest must be convex, but also the armrest has to be changed. In most seats known from the art, the armrest cooperates with the backrest and the base frame at a position directly facing the knees of the occupant of the seat behind, thus precluding the possibility to achieve the objective of this FEATURE 2. The seat of this invention has an armrest that cooperates with the seat pan. The armrest may be fixed or retractable (as schematically shown in Figure 8).

FEATURE 1 AND FEATURE 2 FURTHER BENEFIT- COMFORT

We discovered that a seat comprising an XZ outer boundary shaped as the arc of a circle and a convex XY outer boundary offers an increased feeling of comfort to an occupant. In particular, FEATURE 1 and FEATURE 2 were reduced to practice with the following sizes: Ri between 1000 and 1400mm, w between 430 and 500 mm, s between 350 and 450 mm, hi between 350 and 500 mm, h2 between 1000 and 1400 mm, h3-h1 between 650 and 850 mm, ri between 250 and 350 mm, ai between 40 and 60 degrees, δ between -30 and 30 degrees. The high level of comfort of the seat was confirmed by test persons of various height, weight, sex, age. Further increased comfort was experienced for: Ri between 1 100 and 1250mm, w between 450 and 480 mm, s between 380 and 430 mm, hi between 400 and 450 mm, h2 between 1000 and 1400 mm, h3-h1 between 700 and 800 mm, ri between 280 and 300 mm, ai between 45 and 55 degrees, δ between 0 and 10 degrees. FEA TURE 3 : ROTA TION DE VICE

A device (shown in Figure 9) comprising a sliding body (1 1) and a guide (12). On a XZ coordinate system, the sliding body and the guide are shaped approximately as annular sections of concentric circles (50, 51 , 52, 53), with center (10). The sliding body (1 1) slides on (side by side, into, onto, etc.) the guide (12), whereas the sliding movement causes either the sliding body, the guide, or both elements, to rotate around the center (10) of circles (50-53). The main objective of the invention is to impart to an object cooperating with either the sliding body or the guide, a rotating motion around an axis.

The device may further comprise means to facilitate the sliding motion, for example an actuating mechanism and bearings.

Figure 9 shows two embodiments of the mechanism of the invention comprising a sliding body (11) and a guide (12). Embodiment (A) shows a guide (12) shaped as a channel, closed at the top, constraining the movement of the sliding body (1 1) to a rotation around center (10) in and out the channel (Part A, Position 1 and 2). Other relevant embodiments similar to embodiment A comprise a guide shaped as a channel closed at the bottom or open at both ends.

Embodiment (B) shows an example with the sliding body (1 1) positioned parallel to the guide (12), towards the center (10). The guide (12) constrains the movement of the sliding body (11) to a rotation around center (10) parallel to the guide (Part B, 1 and 2). Other relevant embodiments similar to embodiment B comprise a guide placed inwardly.

In all embodiments, both guide and sliding body may rotate or one of the two elements may be fixed.

The rotation device of this invention is controlled by an actuating mechanism, which can be realized applying technologies well known in the art, comprising mechanical, pneumatic and hydraulic actuating technologies.

Figure 10 shows an embodiment of the invention comprising a toothed part and a gear. Further the embodiment comprises at least a bearing to facilitate sliding of the body in the guide.

Figure 1 1 shows a further embodiment of the rotation device comprising a mechanical actuating mechanism utilizing springs and bearings. The use of springs is interesting in connection to the application of the rotation device in a bucket seat as springs can absorb a shock and therefore can contribute to make the seat safer and / or more comfortable. The guide (12) is an annular channel. The sliding body (11) has a sliding end (21) comprising bearings (19) and a connecting end (20), which cooperates with a further body, which is meant to rotate by means of the rotating device - for example a seat that reclines by rotation according to FEATURE 1. The connecting end, or top part, (20) is truncated in the figure. The top part (20) may be a short structure upon which the seat is fixed, for example through the seating pan; or it can be a long structure acting as the spine of the seat backrest. The shape of the top part (20) has no relevance with regards to the discussion of this paragraph. The mechanism further comprises a case (16), also shaped as an annular channel and comprising a toothed part (17). The case (16) is concentric with the sliding body (11) and the guide (12). The case (16) can slide inside the guide (12); the sliding body (1 1) can slide both inside the guide (12) and the case (16). The sliding movements of the mechanism may be facilitated by bearings (19). A gear (18), housed in a case (not shown) that fixes the position of the gear shaft with respect to the guide (12), has cogs that mesh with the toothed part (17) of the case (16). By rotating the gear shaft, the gear engages the case (16) which slides inside the guide (12). A spring (15) is positioned below the sliding end (21) of the sliding body (1 1). Another spring (14) enwraps the sliding body and it is constrained between the sliding end (21) of the sliding body (1 1) and the lower part of the case (16). When a weight is positioned on the connecting end, or top part, (20) of the sliding body (11) and/or when the case (16) is pushed further inside the guide (12) by means of rotating the gear (18) the sliding end (21) is pushed down, compressing spring (15). Spring (15) exercise a reaction force on sliding end (21) in the opposite direction, thereby compressing spring (14). For any position of the case (16) with respect to the gear (18), and for any weight of a body positioned on the connecting end (20) of the sliding body (1 1), the position of the connecting end (20) is the equilibrium position resulting from the action of the forces and the reaction of springs (14) and (15). In this embodiment, both springs (14) and (15) are under compression. Spring (15) pushes the lowest side of the sliding end (bottom part) (21) of the sliding body (11). Spring (14) pushes between the highest side of the bottom part (21) of the sliding body (1 1). The position of the top part (20) of the sliding body (11) is determined by the relative forces of reaction to compression of both springs. In this figure, spring (15) is shown to be more extended than spring (14), meaning that the resistance to compression of spring (15) is larger than spring (14). It should be appreciated that the invention may be performed with one or several springs, and the design of the springs, comprising for example: length, material or combination of materials, various springs coiled together, thickness and in general resistance to compression and extension and points of attachment are subject to optimization with regards to other requirements including comfort and safety of the seats.

Figure 12 shows the rotation device and actuating mechanism of Figure 1 1 in use for rotating a body placed on the connecting end (20). The body could be for example a seat, with or without an occupant, which reclines by rotation according to FEATURE 1. Position (0) is the idle position. In the application as a seat, in position (0), the seat has no occupant. In position (1) a weight presses on the connecting end (20) of the sliding body (1 1) - in the example: an occupant sits on the seat in straight position. The sliding body slides downward in the guide, compressing spring (15). By reaction, spring (15) pushes against the sliding end (21) of the sliding body (11), which in turn pushes against spring (14), compressing it. The final position of the sliding body is the result of the equilibrium of the forces acting on the springs and the reaction of the springs. Spring (15) may also be designed to absorb part of such force on (20) by extension (spring (15) is than attached to the case (16) and to the bottom part (21) of the sliding body (11), not shown in the figures). When spring (15) is compressed, spring (14) may extend - up to rest position - or even oppose the forces by extension. If spring (15) does not attain rest position, the reaction to compression of spring (14) applies a force on spring (15) and on the sliding body, via the bottom part (21) of the sliding body (1 1). The position of the top part (20) of the sliding body (11) is given by the weight of the passenger applied to (20) and the forces of reaction to compression of both springs. In position (2), the case (16) is caused to slide downward by means of gear (18) engaging on the toothed part (17) of the case - in the example: the occupant of a seat reclines the seat. The bottom part of the case (16) compresses spring (14) which transmit the force to the sliding end (21) of the sliding body (1 1). This in turn pushes against spring (15). The final position of the sliding body is the result of the equilibrium of the forces acting on the springs and the reaction of the springs. Position (2b) shows a situation similar to position (2) but without a weight (or with a small weight) on the connecting end (20) of the sliding body (11) - in the example: the seat is reclined without a passenger, or with a child on it. The compression force acting on spring (14) are only caused by the case (16), and the final position of the sliding body results from the new combination of forces involved in the system.

Figure 13 shows a further embodiment of the rotation device of Figure 9 activated by a mechanical actuation mechanism. Most of the elements of the mechanism are the same as in Figure 1 1 , with the exceptions that in this embodiment only one spring is used (14) and the spring is fixed in his lower part to the sliding end (21) of the sliding body (11) and in his upper part to the lower part of the case (16). The fixing technologies, (22) and (23) are any of the suitable technologies known in the art, comprising for example welding. In this embodiment, external forces acting on the spring (14) are stretching forces. Position (0) is the idle position. In position (1) a force acts downward on the connecting end (20) of the sliding body (11) - in the example: a person sits on the seat in straight position. The sliding body slides downward in the guide, stretching spring (14). The final position of the sliding body is the result of the equilibrium of the forces acting on the spring and the reaction of the spring. In position (2), the case (16) is caused to slide downward by the gear (18) - in the example: the occupant of a seat reclines the seat. The lower part of case (16) pushes the whole mechanism downward, causing a body cooperating with (20), to rotate - in the example: the seat is caused to recline.

A further variation to the previous embodiments is obtained when a weight acts on the guide (12) rather than on the sliding body (1 1) (Figure 14). When the rotation device is used to recline a seat, this embodiment may be performed with the guide along the back of the seat

(comprising also the case in which the back of the seat acts as a guide). Figure 15 shows the rotation device of Figure 14 in a bucket seat application. The rotation device permits high flexibility in reclining the seat, which can be tilted to a position allowing the occupant to stand up (Position B), to a position in which the occupant almost lays down (Position C).

The rotation device may comprise means to fix it to other structures. For example, the

embodiment of Figure 15, applied to seats of airplane cabins, can be fixed via the connecting end (20) of the sliding body (11) to the floor tracks, which fix the seats to the floor of the airplane.

FEATURE 1 AND FEATURE 3: FURTHER BENEFIT - SAFETY

Five solicitation directions are identified as critical and are therefore subject to testing prior to a seat safety approval: forward (according to the nomenclature chosen in this text and with the XZ coordinate systems shown in the figures, X positive, when seats are facing forward), rearward (X negative), towards the bottom (Z negative), towards the top (Z positive) and side. The most critical are the forward and downward directions, which are also tested with dynamic tests. The other directions are tested with static tests

Upon a crash, forces as pictured in Figure 17 develop. Figure 17 (A), (B) and (C) show the qualitative vectors representing an impact force (60), the reaction force on the seat (61) and the force acting on the passenger's upper body (62) in case of a forward impact (A), an aft impact (B), and a downward impact (C). Figure 18 shows the reaction of the rotation device upon an impact. As a consequence of an impact forward (Figure 17 A) and downward (Figure 17 C), the seat slides downward. The passenger's body is subject to the reaction forces, which are reduced with respect to standard forces acting on a passenger's body, both because partially absorbed by the springs and because of vectorization. The passenger is pushed downwards towards the seat pan and the upper part of the body is pushed towards the backrest with a rotational movement.

Upon an aft (rearward) crash or impact, the forces of action and reaction on the seat are as shown in Figure 17 (B). Figure 18 (Position 2) shows how the rotation device react to the aft crash. The passenger accompanies the seat movement upwards and the upper body is pushed towards the backrest.

The striking feature of the structure is that subject to common crash (impact) patterns (for example a forward crash or to a downward crash caused by uncontrolled landing) the rotation device absorbs part of the impact and vectorise the forces acting on it. The passenger is thus subject to forces of reduced magnitude. Moreover, the passenger is pushed always towards the backrest. The passenger's head thereby does not follow the common trajectory known in seats of the art and thus the risk of head injury is minimized for all passengers, regardless of the passenger's height.

As already indicated earlier, an embodiment comprising a fixed guide at the bottom and the sliding body protruding from the upper part of the guide and sliding in and out the guide is only one of the many ways of performing the invention, although the description and the

nomenclature focus on this embodiment. It should be appreciated that a rotation device comprising a fixed sliding body at the bottom and a guide on top of it, sliding around the sliding body in a rotary path also embodies the invention. Alternatives, where the guide and the sliding body do not fully enwrap each other but rather cooperate, for example slide parallel to each other in a tongue-groove fashion are also suitable embodiments. Also the spring may be encased in the guide, and activated by the sliding body, but it also may surround the sliding body and be compressed or extended by the guide.

FEATURE 4: A BUCKET SEAT WITH PRIVACY CANOPY

Sitting in tight arrangements, for example in airplane cabins, may feel uncomfortable for passengers because of the close eye contact with other passengers at the side. The feeling of discomfort may be even more pronounced when the backrest of the seat is reclined.

A bucket seat comprising a privacy canopy protects the seat occupant from the sight of other passengers. A privacy canopy may be designed according to the principles of the existing art of sun canopies in baby seats and prams (Figure 16) and it may be fixed or retractable. A privacy canopy for seats on public means may comprise paper tissues to the purpose of frequent changing to improve hygiene. This feature may be used together with the features of the previous paragraphs or independently.

FEATURE 5: BASE FRAME AND COOPERATION WITH RECLINE MECHANISM In seats known from the art, a base frame assembly comprise typically a pair of stretcher tubes joined by spreaders and various removable leg assemblies. The number of spreaders is equal to the number of seats in the row plus one. The number of leg assemblies is typically 2 for rows of 1 , 2, and 3 seats; 3 for rows with 4 seats, and 4 for rows with 5 seats. In addition, the base frame comprises a baggage bar.

The seat of this invention benefits of a novel base frame. Appropriate design of the base frame may simplify the construction and further improve the safety of the passengers.

A suitable base frame to for the seat is shown in Figure 19 (A). The base frame comprises spreaders which also act as removable legs (72). The removable leg assemblies have track fittings (not shown) to fix the seat to the seating tracks (or rails) (76). The spreaders acting as removable legs comprise passages (74) of a shape suitable to accommodate stretcher tubes (75). The passages may be simple holes. However, in practice, to facilitate assembly and disassembly of the base frame, or part of the base frame, on board an aircraft, instead of holes, the spreader may comprise a system of stirrups and saddles to fix the stretcher tubes (not shown in the figures). Cooperation systems of this kind may be found in other applications. The detailed design of the spreaders, including the stirrup-saddle system, in terms of shape, material, presence of lightening holes, reinforcement is dictated by various criteria, comprising need of forward/rearward installation flexibility, ability to absorb compression and extension forces, deformation, weight. In some embodiments, additional spreaders (73) may be needed at the edges of the base frame to improve stability. In some embodiments, the stirrup-saddle system may be such to allow the stretcher tube some degrees of freedom

The base frame further comprises at least one stretcher tube (75). Figure 19 shows an embodiment with three stretcher tubes. The stretcher tubes are dimensioned such to optimize stability and energy absorption upon a crash. The stretcher tubes are not necessarily circular and may be full or hollow. If a design with more than one stretcher tube is selected, the stretcher tubes may have different cross section, and they may be manufactured in different materials. Also the section and /or the thickness of the stretcher tube is not necessarily constant throughout the tube/ The shape, the dimensions and the material of a stretcher tube are critical to impart stability to the seat, absorb energy during a crash and control deformation and to determine the weight of the base frame.

The guide (12) of the rotation device is shown in the embodiment depicted in Figure 19 (B) as a tube with an axis formed as the arc of a circle and a circular cross section. The guide is connected to the stretcher tubes. Various connecting devices can be envisaged. In Figure 19 (B) we show an embodiment comprising wings (80) welded to the guide (12), the wings comprising passages (81) to accommodate the stretcher tubes. Similar to the spreaders, also the connecting device may comprise simple passage systems, as for example holes, or a system that facilitate assembly, disassembly, and maintenance, as for example stirrups and saddles.

Figure 19 (B) shows also the top part of the sliding body (20). In this embodiment, the top part (20) of the sliding body is schematically shown as the spine of the seat: a bar of rectangular cross section, bent as an arc of a circle. The figure shows the top part (20) of the sliding body only schematically. The cooperation between the top part (20) of the sliding body (1 1) and the seats, may be achieved by several methods. For example, the top part (20) may cooperate with the seat pan (1 1), as for example schematically shown in Figure 20 (A). With an embodiment such as this, in order to achieve the purpose of the invention (recline the seat without intruding in the space behind), the back side of the backrest (90) have to be shaped as the arc of a circle in the plane XZ, concentric with the arcs of circles formed by the sliding body (1 1), the guide (12), the case (16) and the springs (14 and 15). The radius of the circle however may be different. In the case of the embodiment shown in Figure 20 (A), the radius of the back side of the backrest is bigger than the radius of the sliding body. Some embodiments of a top part (20) suitable for the invention according to the cooperation type shown in Figure 20 (A), are shown in Figure 21 (A-C). Embodiment (A) shows a simple top part that offers cooperation with the seat pan. In this case, the seat pan needs cushion and support. Embodiment (B) shows a wider top that embraces a large part of the seat pan, and which can directly serve as support to the cushions. Embodiment (C) shows a top part (20) embracing most of the seat pan and

comprising armrests. This is further detailed in the paragraph on FEATURE 7. Variations and combinations on the top part (20) are easily envisaged. Other parts of the seat, comprising for example armrests (as seen in (C)) and backrest, may cooperate with the top part (20).

The cooperation between the sliding body and the seat can also be achieved differently. For example, Figure 20 (B) shows an embodiment where the top part (20) is an elongated structure that supports the backrest. In the figure, the top part (20) of the sliding body (1 1) is shown to have the same cross section (in direction XZ) as the sliding body (1 1). This is not necessary for the invention. The top part (20) forms the spine or the frame of the back rest and supports the cushions for the backrest (90) and the seat pan (91) (more clearly seen in Figure 20 (C)). The shape of the top part (20) of the sliding body (1 1) has to be suitable to function as support.

Various embodiments may be seen in Figure 21 (D-F). With this cooperation type, a method of stabilization between the support of the seat pan and other elements of the base frame, besides the sliding body, can be helpful to increase the strength of the seat pan and resistance to load (including crash). One such methods of stabilization is shown in Figure 22, where a stabilization body (92) connects the seat pan (91) to the guide (12). The stabilization body of this

embodiment requires that either the end in contact with the guide (12) or the end in contact with the seat pan (92) (or both) slide. To this regard, notice part A, showing a seat in straight position, and part B, showing a seat in reclined position, of Figure 22. Part (B) shows an embodiment where the end in contact with the seat pan (91) is fixed, while the end in contact with the guide (12) slides. Sliding may be performed, for example, by means of a slide on a rail (94) (visible in Figure 22 (C)). If the seat pan is allowed to rotate in the plane XZ at the connection with the backrest (93) in order to further increase the degrees of freedom in reclining, the stabilization body (92) requires the ability to reduce its length. This may be achieved with mechanical systems, like pistons and springs or hydraulic systems. Details are not shown in the figures. Further details, including reinforcements, structural holes (for example for controlled

deformation), lightening holes, fixation points for structural elements, fixation devices, cushions, entertainment devices and other accessory parts etc. are not shown in the figures.

The base frame disclosed here teaches a method to support the seat and connect it to the seating rails of an aircraft. Thus, it teaches a method to perform of the invention.

As an independent important benefit of the base frame disclosed here, the construction with the guide fixed by means of rods (the stretcher tubes) adds further flexibility to the optimization of energy absorption upon crash or other sudden loads. Upon the action of a force acting on the rail fittings (for example a sudden impact of the aircraft) or on the guide (originating from the passenger, for example in connection with turbulence) in any likely direction, the base frame reacts by twisting the rods. This creates another device to absorb partially absorb the forces cause by the impact, and to vectorize the reaction forces, such that the forces transmitted to the passenger are minimized. Figure 23, shows a conceptual representation of the reaction forces opposing a load applied on the seat.

A further benefit of this construction is that the stretcher tubes and the spreaders do not occupy space in correspondence of the knees of a tall passenger sitting behind. Thus the base frame releases space that has significant comfort, and sometimes medical, value for tall passengers. This is further discussed in FEATURE 7.

An even further benefit of the invention is that the back rest structure can be designed such to act as a support for a 3- and 4- points safety belt.

FEATURE 2 AND FEATURE 5: FURTHER BENEFIT - SHORTER PITCH

We discovered that a seat comprising a convex XY outer boundary and a base frame which protrude minimally towards the negative X values in a XY coordinate system adds such a significant room to the knees of the passenger behind, that the seat rows may be

accommodated with a shorter pitch than typical in the art. In particular, when the seat was reduced to practice with the following sizes: Ro between 1 100 and 1250mm, w between 450 and 480 mm, s between 380 and 430 mm, hi between 400 and 450 mm, h2 between 1000 and 1400 mm, h3-h1 between 700 and 800 mm, ro between 290 and 310 mm, ai between 45 and 55 degrees, δ between 0 and 10 degrees, a pitch of 27" was perceived as confortable from the test persons. FEATURE 6: SUPPORT FOR IN-FLIGHT ENTERTAINMENT

For the optimum comfort of passengers sitting in rows of seats, the In-Flight Entertainment (IFE) elements, for example a video screen, and flight amenities as the tray and the magazine holder, should not change position when the passenger in front reclines or put the seat in straight position. For easing the text, we will include flight amenities under the general acronym "IFE") We invented an IFE support structure (82), applicable to this seat, that specifically solves this problem. The device of the invention has a cross section in the plane XZ. At least the outermost side of the cross section (for each Z level, the points of the cross section having lowest X) is shaped as the arc of a circle, concentric with the arc of the circle formed by the sliding body (1 1). The device is fixed to the guide (12) at the position (83). The shape of the device in other planes than the plane XZ is not critical, and many embodiments are possible. Various methods of fixation in position (83), of the types known from the art, may be used. These comprise permanent, for example welding or one-structure moulding, and removable fixation techniques, for example screws and bolts, or quick releases.

Figure 24 (B) shows and embodiment of a IFE support structure (82). In this embodiment, the external (towards decreasing X on the abscissa scale) radius of the arc formed by the top part (20) of the sliding body (1 1) is just slightly smaller than the internal arc formed by the IFE support structure (82) such that the top part (20) slides parallel to the IFE support structure (82). In other embodiments, the IFE support structure (82) may be positioned internally (not shown) - referring to Figure 19 (B), on a higher X value on the abscissa scale) with respect to the top part (20) of the sliding body (1 1). In this case, the top part (20) has a just slightly higher radius than the IFE support structure (82). Alternative embodiments are further seen in Figure 24 where the IFE support structure (82) is positioned within two branches of a top part (20) shaped as a frame (part A). Part B shows the opposite arrangement, with an IFE support structure having two vertical branches and the top part (20) being positioned in the middle of the two.

As long as relative sliding, preferably smooth, between the top part (20) and the IFE support structure (82) is achieved, the number of branches, disposition with respect to top part (20) and other specifications of the support (82) are not critical to the performance of the invention and they are dictated by mechanical criteria (stability, weight) aesthetic criteria, and by the possibility to accommodate cables and other necessary elements of the seat.

A schematic representation of how the screen appears to the passengers is made in Figure 25. The left hand side of the figure, parts A, B, C, and D, shows four rows of seats on a XZ view, whereas 2 are in straight position (A and D), and 2 are in reclined position (B and C). The right hand side shows the YZ view of the screen from the passenger behind. In particular, (E) shows how seat (A) and (D) (non-reclined) and their screens look like; and (F) shows how seat (B) and (C) and their screen look like: reclining of the seat in front does not affect the position of the screen - thus the passenger in front is free to move in their seat without limiting the freedom of the passenger behind.

As schematically shown by Figure 25, when passengers (B) and (C) recline, the screen position may not be optimal with respect to the position of the head of the passenger. Embodiments of the invention may advantageously include techniques to tilt the screen such that the screen remains approximately perpendicular to the viewing cone of the passenger behind, as passenger (C) has done with the screen sitting on the backside of seat (B). Devices that allow achieving this purpose are known in the art, for example, in cars' side mirrors. Alternatively, or in addition to that, the IFE support structure (82) may be provided with a technology that allows to position the screen higher or lower according to the need. Simple devices that allow to achieve this purpose are known in the art, for example in regulating the height of the shower head (not shown). While these features may further improve the comfort of all passengers, regardless to their height, these additional features are not necessary to perform the invention.

Although the foregoing discussion and the figures focus on a videoscreen, the same invention can be used as a support to tray, magazine holder and other IFE / flight amenities, which are conveniently positioned on the back of a seat, to be enjoyed by a passenger sitting behind. The support structure (82) does not move when the sliding body (1 1) slides from reclined to straight position and vice versa, such that the passenger behind does not perceive nuisance when the passenger in front changes position.

FEATURE 7: ARMREST

In the seats known from the art, the spreaders keep the stretcher tubes parallel and provide the support for the recline mechanism of back rest, the seat table and the armrests. We noticed that with the present design, the spreaders and the armrests are located in correspondence of the knees of tall passengers behind. The spreaders and the armrest block the knees of tall passengers both in direction X and Z, meaning that they protrude too much behind (direction of decreasing X) and they are too tall (direction of increasing Z). To increase the knee space for a passenger, the base frame and the armrest construction must be revised.

Earlier in this application we disclose a novel method of construction of the base frame and of the IFE support structure. The inventions teach how to avoid spreaders and IFE support structures that protrude behind, in correspondence of the knees of tall passengers.

A further invention is related to the armrests. Contrary to other seats of the art, in the seat of the invention the armrests are no longer supported by the spreader. Instead, the armrests cooperate with other elements of the seat, such that no elements of the armrest protrude behind the seat. Figure 26 shows projections on the plane XZ and XY of passengers sitting on the seat of the invention. The figure shows a schematic representation of the armrests and it evidences how a rotation of the knees, both on the XZ and XY planes (Part A and B, centre and right passengers), are allowed without finding impediment from the armrests. The figure also evidences that only passengers with unlikely long and bent femurs are likely to hit the armrest of the seat in front, when the femur rotates around its head. If the pitch between the seats is narrow, tall passengers may still be impeded to rotating the knees towards the centre (midline M, as seen on part B). Still, with this novel construction, the passengers will be able to rotate the femoral head with fairly high freedom om plan XZ and on plane XY, away from M. Rendering of a seat with the armrest of the invention can be seen in Figure 27.

Embodiments of the invention are armrest cooperating with the support of the seat pan, or with the top part (20) of the sliding body (11) (Figure 20 (A)) as for example schematically shown in Figure 21 (C). The cooperation method has to ensure strength against a certain load. Such strength may be achieved by many cooperation techniques known from the art, including welding (if both parts that cooperate are metallic), structural moulding (if not metallic), screws and bolts, wedges, and many other. The armrest may be also made in one unique piece with any or all of the other rotating parts, such as the sliding body (11), top part (20), backrest (90), seat pan (91).

For optimum comfort, the armrest shall recline together with the seat. Thus, it should be appreciated that the armrest may easily cooperate with any of the seats part that follow the movement of the seat pan upon reclining.

This invention is not only related to the seat disclosed here. Even seats already known in the art, for example with the classic bench-like base frame, may benefit of armrests fixed at the seat in another position than the rear part of the spreaders. On seats known from the art, the armrests of this invention may be connected in other positions. For example, referring to Fig. 1 and Fig. 2 of Patent 5, 553, 923, the armrests of our invention could be connected close to position 36 b. The armrests cooperating with the seat pan such that (a) they do not come in the way of the knees of the occupant behind. A further benefit of our disclosed armrest is that (2) they are independent, so that each passenger can enjoy both its armrests.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further illustrated by the accompanying drawings showing examples of embodiments of the invention.

Figure 1 : Graphic representation of a curve approximating a circle in at least part of the curve. Figure 2: Schematic of the outer (rear) side of the backrest and part of the reclination mechanism.

Figure 3: Schematic representation of the seat of the invention and its objective.

Figure 4: An embodiment of the seat of the invention with a movable seat pan.

Figure 5: The seat of the invention, straight or reclined, with occupants - various views.

Figure 6: Main part of a XY outer boundary in various embodiments.

Figure 7: Various embodiments of the seat with FEATURE 2 in a YZ plane.

Figure 8: Seat of the invention with an armrest cooperating with the seat pan.

Figure 9: Embodiments of the rotation device of the invention comprising a sliding body (1 1) and a guide (12).

Figure 10: Embodiment of the rotation device comprising a toothed part, a gear, and bearings. Figure 1 1 : XZ view of an embodiment of the rotation device comprising an actuating mechanism utilizing two springs.

Figure 12: rotation device and actuating mechanism of Figure 11 in use for rotating a body placed on the connecting end (20) of the sliding body (1 1).

Figure 13: A further embodiment of the sliding mechanism of Figure 9 utilizing one spring. Figure 14: Rotation device and actuating mechanism of Figure 11 in an application where a force pushes on the end part of the guide (12).

Figure 15: Rotation device in service to recline a rotating bucket seat.

Figure 16: An embodiment of a bucket seat with a privacy canopy.

Figure 17: Qualitative representation of the forces developing upon the seat of the invention and a passenger upon a crash.

Figure 18: Reaction of the rotation device to a forward and downward crash (Position 1 , 1 b) and to an aft crash (Position 2); Position 0 is in the steady condition.

Figure 19: (A) Embodiment of a base frame assembly; (B) Rotation device fixed to the base frame assembly.

Figure 20: Alternative methods to achieve cooperation between the sliding body (1 1) of the rotation device and the seat.

Figure 21 : Embodiments of a top part (20) cooperating with the seat pan (91) and the seat back rest (90).

Figure 22: Stabilization body (92) connecting the seat pan (91) to the guide (12). Figure 23: Conceptual representation of the reaction forces acting on the base frame of the invention opposing a load applied on the seat.

Figure 24: Examples of shapes and relative positioning othe IFE support structure (82) respect to the top part (20) of the sliding body (11).

Figure 25: A schematic representation of how the screen appears to the passengers behid, when the back support is straight (A, D) or reclined (B, C).

Figure 26: Projections on the plane XZ and XY of passengers sitting on the seat of the invention show armrests are not in the trajectory of rotation of the knees.

Figure 27: Rendering of a seat with the armrest of the invention

POSITION NUMERALS

1 Backrest

2 (XZ) Outer boundary of a backrest

3 Reclination mechanism (or part of it)

4 (XZ) Outer boundary of a backrest

5 Circle with center 10 and radius R

6 Approximating curve

10 Center of a physical or virtual circle

1 1 Sliding body

12 Guide

14 Spring

15 Spring

16 Case

17 Toothed part

18 Gear

19 Bearings

20 Connecting end, or top part, of the sliding body

21 Sliding end, or bottom part, of the sliding body

22 Spring fixing technology

23 Spring fixing technology

50, 51 , 52, 53 Circles of center (10)

60 Impact force, qualitative vector

61 Seat reaction force, qualitative vector

62 Force acting on passenger upper body, qualitative vector

63 Component of a force transmitted to the guide (12)

64, 65, 66 Reaction forces on elements of the base frame

72 Spreader acting as removable leg

73 Terminal spreader

74 Spreader passage for stretcher tube (may be a hole or a stirrup-saddle system or other fixation system)

75 Stretcher tube

76 Seating rail (or track)

80 Guide wing (part of the connecting device)

81 Connecting passage for stretcher tube (may be a hole or a stirrup-saddle system or other fixation system)

82 IFE support structure

83 Position of fixation of the IFE support structure to the guide

90 Back side of the backrest 91 Seat pan

92 Stabilization body

93 Rotation point of the seat pan

94 Guide rail

LETTERS

ai angle formed between the tangent to the XZ outermost boundary (or inner side of the backrest support, of the thickness of the backrest support is not negligible) and the higher end of the seat pan

g, β, v angles formed between the tangent to the XZ outermost boundary and the higher end of the seat pan

δ angle between the seat pan and a parallel to the floor

d distance, pitch

D Distance

F1 , F2, F3 Points on a curve or on a surface

hi distance of higher end of the seat pan from the floor,

h2 distance of center 10 from the floor

h3 distance of top of backrest support from the floor

R radius of circle 5

ri radius of the inner side of a backrest support shaped as an arc of a circle in a XY

coordinate system

ro radius of a XY outer boundary shaped as an arc of a circle

Ri radius of the inner side of a backrest support shaped as an arc of a circle in a XZ

coordinate system

Ro radius of a XZ outer boundary

R1 , R2, R3 Points on a curve or on a surface

s depth of the seat pan

w width of the seat pan DETAILED DESCRIPTION OF THE DRAWINGS

A number of embodiments of the invention will be explained in more detail in the following with reference to the drawings.

Figure 1 : Graphic representation of a curve approximating a circle in at least part of the curve. The section between points (F2) and (F3) may belong to a circle (5) of center (10), or to the ellipses (6). Ellipses (6) is approximately circular between (F2) and (F3) and a point (F1) moving between (F2) and (F3) moves in an approximately circular trajectory.

Figure 2: Schematic of the outer (rear) side of a backrest (1) and part of a reclination

mechanism (3) moving along an approximate circle. Position 1 is the straight position of the backrest, position 2 is a reclined position of the backrest. The embodiment in Part (A) comprises an XZ outer boundary (2) and a part of the reclination mechanism (3), approximately shaped as circles, having approximately same center (10) and same radius. The embodiment in Part (B) comprises an XZ outer boundary (2) and a part of the reclination mechanism (3), approximately shaped as circles, having same approximately center (10) but different radius. In this specific embodiment, (3) has a smaller radius than (2). The opposite is also an embodiment of the invention.

Figure 3: Schematic representation of the seat of the invention and its objective. Part (A): seat F is in straight position. In this embodiment, the XZ outer boundary of the backrest (stapled line) (2) and the outer boundary of the reclination mechanism (3) coincide. R1 , R2, R3 are points on a still body behind seat F (here on an occupant of seat R). F1 , F2, and F3 are points on the XZ outer boundary of seat F. D1 , D2, and D3 are the distances between R1 , R2, R3 and F1 , F2, F3, respectively. Part (B): seat F is in reclined position. The XZ outer boundary of the backrest (stapled line) in reclined position is (4). The XZ outer boundaries (4) and (2) are arcs of the same circle; R1 , R2, R3 are points on a still body behind seat F (here on an occupant of seat R). F1 , and F2 are points on the XZ outer boundary of seat F. D1 and D2, are the distances between R1 , R2 and F1 , F2, respectively. When seat F reclines, D1 and D2 are the same as with seat F in straight position. Point F3 does not fall anymore on the XZ outer boundary of the backrest and the distance between point R3 and the nearest object, in the same direction of D3, increases.

Figure 4: An embodiment of the seat of the invention with a movable seat pan. The seat pan may be movable with respect to the backrest, forming various angles with the tangent to the XZ outer boundary. Position A shows backrest and seat pan in straight position (angle a). Position B shows the backrest in reclined position and the seat pan in resting position (angle β); Position C shows the backrest in straight position and the seat pan in resting position (angle β). d represents the distance between the centers of two adjacent circles, the pitch. Although with the proportions chosen for these drawings the distance d is similar to the radius of each circle, these dimensions may or may not be the same.

Figure 5: The seat of the invention, straight or reclined, with occupants. Part (A) is the XZ plane; Part (B) is the XY plane at Z=Z1 : just above knee height; Part (C) is the XY plane at Z=Z2: above the heads of the occupants. Figure 6: Main part of a XY outer boundary in various embodiments.

Figure 7: (A), (B), (C) are embodiments that exemplify the invention as to the shape of the backrest in a XY plane. In order to achieve the objective of the invention, the XY outbound curve should be convex at least between the height Z3 and Z4, within which the knees of the passenger behind the seat can be reasonably positioned, as schematically shown in the XZ plane. Embodiment (A) is a backrest with constant curvature. Embodiment (B) is a backrest with progressively changing curvature, with increasing radius at increasing distance from the seat pan. Embodiment (C) is a backrest convex in the lower part and straight in the upper part. Figure 8: Seat of the invention with the armrest cooperating with the seat pan. In this

embodiment the armrest can rotate around point F and point R to retract on the seat pan.

Figure 9: Embodiments of the rotation device of the invention comprising a sliding body (1 1) and a guide (12). On an XZ plane, the sliding body and the guide are shaped as annular arcs of concentric circles (50, 51 , 52, 53), whereas (10) is the center of the circles. Embodiment (A) shows a guide (12) shaped as a channel; Embodiment (B) shows an example with the sliding body (11) positioned inwards the guide (12), towards the center (10). Position 1 and 2 show the changing relative positions of sliding body and guide upon activation of the device. Figure 10: Embodiment of the rotation device comprising a toothed part, a gear, and bearings.

Figure 1 1 : XZ view of an embodiment of the rotation device comprising an actuating mechanism utilizing two springs. The guide (12) is an annular channel. The sliding body (1 1) has a sliding end (21) and a connecting end (20), which cooperates with a further body, which is meant to rotate by means of the rotating device - for example a seat that reclines by rotation. The mechanism further comprises a case (16), also shaped as an annular channel and comprising a toothed part (17). The case (16) is concentric with the sliding body (11) and the guide (12). The case (16) can slide inside the guide (12); the sliding body (11) can slide both inside the guide (12) and the case (16). The sliding movements of the mechanism may be facilitated by bearings

(19) . A gear (18), housed in a case (not shown) that fixes the position of the gear shaft with respect to the guide (12), has cogs that mesh with the toothed part (17) of the case (16). By rotating the gear shaft, the gear engages the case (16) which slides inside the guide (12). A spring (15) is positioned below the sliding end (21) of the sliding body (1 1). Another spring (14) enwraps the sliding body and it is constrained between the sliding end (21) of the sliding body (11) and the lower part of the case (16).

Figure 12: Rotation device and actuating mechanism of Figure 11 in use for rotating a body placed on the connecting end (20) of the sliding body (1 1). Position 0: the rotation device is not solicited; Position (1) the rotation device is solicited by a force applied at the connecting end

(20) of the sliding body (1 1). Position (2) the rotation device is rotated by means of rotating gear (18), which engages the toothed part (17) of case (16). Furthermore it is solicited by a force applied at the connecting end (20). In position 2b the device is rotated my means of rotating gear (18), but there is no force applied to (20).

Figure 13: A further embodiment of the sliding mechanism of Figure 9. Most of the elements of the mechanism are the same as in Figure 1 1 , with the exceptions that in this embodiment only one spring is used (14) and the spring is fixed in his lower part to the sliding end (21) of the sliding body (11) and in his upper part to the lower part of the case (16).

Figure 14: rotation device and actuating mechanism of Figure 11 in use for rotating a body which exercise a force on the top end of the guide (12). Figure 15: Rotation device in service to recline a rotating bucket seat. The flexibility of the arrangement is such to permit rotation from a sitting straight position (Position A) up to a standing position (position B) and down to an almost laying position (position C).

Figure 16: An embodiment of a bucket seat with a privacy canopy, here applied to the other inventions of this provisional patent application. The canopy may be retractable.

Figure 17: Upon a forward and downward crash, the seat slides downward. The passenger's body is subject to the reaction forces, the magnitude of which is reduced with respect to standard forces acting on a passenger's body, both because the impact is partially absorbed by the spring but also because the curved shape causes a vectorization of the forces. The passenger is pushed downwards towards the seat pan and then towards the backrest. Upon an aft crash, the seat slides upward. The passenger's body is subject to the reaction forces, the magnitude of which is reduced with respect to standard forces acting on a passenger's body, both because the impact is partially absorbed by the spring but also because the curved shape causes a vectorization of the forces. The passenger accompanies the seat movement and it is pushed towards the backrest. Figure 18: the reaction of the rotation device upon an impact. Position 0 is the rotation device in steady conditions. Position 1 and 1 b qualitatively represent the situation of a forward and downward impact. When a reaction force (62) pushes on the top part (20) of the sliding body (11), the seat slides downward compressing spring (15). Spring (14) may be totally released from compression and from any tension, as in position 1 , if the ends of spring (14) are not fixed to the rest of the structure. Also, spring (14) may be subject to extension forces if the bottom end of spring (14) is fixed to the sliding end (21) of the sliding body (11) and the top end of spring (14) is fixed to case (16). Spring (15) absorbs part of the impact by compression. Thanks to the curved shape of the structure and springs (14 and 15) the impact is vectorised, thus decomposing the forces impacting on the passenger's body and thus reducing the magnitude of impaction. Position 2 shows how the rotation device react to an aft crash. By reaction the seat slides upwards. Spring (14) is compressed, absorbing part of the shock. Spring (15) is either released, or, if it is fixed at both extremities, it is extended, thus contributing in absorbing part of the impact forces and vectorising them. Figure 19: (A) Embodiment of a base frame assembly. The base frame comprises spreaders which also act as removable legs (72). The figure also shows terminal spreaders (73) which may be needed in some embodiments to add stability. These spreaders comprise passages (74) of a shape suitable to accommodate the stretcher tubes (75). This figure shows an embodiment with three stretcher tubes. (B) Rotation device fixed to the base frame assembly by means of a fixation device here embodied by wings (80) fixed on the guide (12) comprising passages (81) for the stretcher tubes (75).

Figure 20: Alternative methods to achieve cooperation between the sliding body (1 1) and the seat. (A): The top part (20) cooperates with the seat pan (91). With an embodiment such as this, in order to achieve the purpose of the invention (recline the seat without intruding in the space behind), the cross section of the back side of the backrest (90) have to be shaped as the arc of a circle, at least concentric with the arcs of circles formed by the sliding body (11), the guide (12), the case (16). (B) The top part (20) of the sliding body (1 1) is an elongated structure that supports the backrest (91). In this specific embodiment, the top part (20) and the sliding body (11) have same section on the XZ plane. In order to perform the invention, the top part (20) is formed as the arc of a circle, at least concentric with the arcs formed by the sliding body (1 1), the guide (12), the case (16). (C) is the combination of the previous two cases, where the sliding body (11), the top part (20) the backrest (91) and the seat pan (92) are one unique structure. Figure 21 : Shapes of a top part (20) suitable for connecting the rotation device to the seat according to the methods shown in Figure 20. Type (A) shows a simple top part that offers cooperation with the seat pan. In this case, the seat pan needs cushion and support.

Embodiment (B) shows a wider top that embraces a large part of the seat pan, and which can directly serve as support to the cushions. Embodiment (C) shows a top part (20) embracing most of the seat pan and comprising armrests. Other parts of the seat, comprising for example armrests (as seen in (C)) and backrest, may also cooperate with the top part (20). Type (D) shows a top part shaped as a backrest support. The backrest to fit this top part would need only cushioning and, perhaps a back cover. Embodiment (E) shows a narrower top part (20). A backrest to fit with this top part may need structured cushioning. Embodiment (F) shows a top part (20) shaped as a fish bone, to be used as embodiment (D).

Figure 22: Stabilization body (92) connecting the seat pan (41) to the guide (12). (A) seat in straight position, (B) seat in reclined position. (B) shows an embodiment where the stabilization body (92) is fixed at the seat pan, while it slides at the cooperation point with the guide (12). In order to further increase the degrees of freedom in reclining, the seat pan may rotate at point (93). To permit rotation of the seat pan (91), the stabilization body (92) requires the ability to reduce its length. 3D representation of the base frame, where the stabilization body (92) and the rail (94) are visible.

Figure 23: Conceptual representation of the reaction forces acting on the base frame of the invention opposing a load applied on the seat. Figure 24: Examples of shapes and relative positioning othe IFE support structure (82) respect to the top part (20) of the sliding body (11). Part A shows the IFE support structure (82) positioned within two branches of a top part (20) shaped as a frame (part A). Part B shows the opposite arrangement, with an IFE support structure having two vertical branches and the top part (20) being positioned in the middle of the two.

Figure 25: A schematic representation of how the screen appears to the passengers behind. The left hand side of the figure, parts A, B, C, and D, shows four rows of seats on a XZ view, whereas 2 are in straight position (A and D), and 2 are in reclined position (B and C). The right hand side shows the YZ view of the screen from the passenger behind. In particular, (E) shows how seat (A) and (D) (non-reclined) and their screens look like; and (F) shows how seat (B) and (C) and their screen look like: reclining of the seat in front does not affect the position of the screen - thus the passenger in front is free to move in their seat without limiting the freedom of the passenger behind. Embodiments may include techniques to tilt the screen, as passenger (C) has done with the screen sitting on the backside of seat (B).

Figure 26: Projections on the plane XZ and XY of passengers sitting on the seat of the invention. The figure evidences how a rotation of the knees, both on the XZ and XY planes (Part A and B, centre and right passengers), are allowed without finding impediment from the armrests. If the pitch between the seats is narrow, tall passengers may still be impeded to rotating the knees towards the centre (midline M, as seen on part B). Still, with this novel construction, the passengers will be able to rotate the femoral head with fairly high freedom om plan XZ and on plane XY, away from M.

Figure 27: Rendering of a seat with the armrest of the invention.