OR THE LIKE"

FIELD OF THE INVENTION

The present invention concerns an ergonomic seating element such as a sofa, an armchair, a seat or suchlike provided with padded cushions on which a user can sit.

In particular the present invention concerns seating elements produced, even if not exclusively, in hand-crafted or semi hand-crafted field, and allow to improve the seating comfort of the user.

BACKGROUND OF THE INVENTION

The productive steps of sofas and armchairs are based on the creation of a wooden support structure, also called frame, inside which braided elastic bands are applied to support a seating plane and a backrest. Respective cushions are associated to the elastic bands to define the effective seating plane and backrest of the sofa or armchair.

It is known to make cushions for the seat, the backrest and possibly the headrest with monolithic padding in polyurethane of single or plural density. Such cushions are covered in leather or fabric or micro-fiber.

It is also known to associate electro-mechanical mechanisms to armchairs or sofas in order to move some of their parts with the purpose of improving the comfort of use.

There have also been similar efforts made in the automobile sector. In the patent IT 1267347 reduced thickness seating cushions are described, having paddings from which, from the lower part, circular portions in polyurethane are removed. The padding is disposed in contact with a concave containing tank obtained by molding plastic materials. The containing tank is conformed in an appropriate way to contain the transverse deformations of the seating cushion and therefore to reduce the rigidity of the padding in correspondence to a user's ischiatic bones and coccyx.

In the first place, in making sofas and armchairs the use of thinner cushions, that is, with a thickness of less than 6-7 cms, is excluded for aesthetic reasons.

Moreover in the hand-crafted or semi hand-crafted field, the use of plastic materials is excluded a priori, therefore it is not possible to achieve a combined effect between the shape of a plastic tank with the removal of circular portions of polyurethane.

Moreover, the presence of the elastic bands implies a mechanical behavior of the padding that varies in relation to the positioning of the bands, to the tension imparted to the bands during their attachment to the wooden structure, and to the mechanical properties of the bands which, furthermore, alters over time.

What is more, the behavior of padding with furrows in the lower part in direct contact with the elastic bands is particularly inefficient.

It is therefore complex to combine the consolidated practice of manufacturing sofas and armchairs in the hand-crafted or semi hand-crafted field with the need to improve the ergonomics of the products obtained.

From documents US4707025, US5490714, US600754, US6733071 and US7040692 it is also known to associate suspension mechanisms with the seating planes which allow them to pivot horizontally when a user sits down. In particular, the suspension mechanisms allow the seating plane to modify its orientation and position as a function of the movements of the user seated upon it.

The suspension mechanisms comprise a plurality of levers, articulated kinematisms and devices to clamp the position which are particularly complex to make and to manage and which, as such, preclude them from being used in the field of production of sofas or armchairs for the domestic field.

One purpose of the present invention is to make an ergonomic seating element, such as a sofa, an armchair or suchlike which can be made in a simple and rapid way.

Another purpose of the present invention is to make a seating element which is ergonomic and comfortable for the user who has to sit in it.

Another purpose of the present invention is to make a padding system for sofas and armchairs, in hand-crafted or semi-hand-crafted fields, able to improve the ergonomics of the products obtained without affecting the manufacturing tradition of such products.

It is also a purpose of the present invention to perfect a method of making an ergonomic seating element which is simple, rapid and economical. The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, an ergonomic seating element, such as a sofa, an armchair or suchlike, comprising a support structure provided with at least a first frame, which is disposed substantially horizontally in use, and a second frame, disposed substantially vertical in use, solidly associated to the first frame. The first and the second frames are suitable to respectively support a seating cushion and a backrest cushion.

In accordance with one feature of the present invention, between at least one of either the first or the second frame, a respective panel is provided on which the seating cushion or the backrest cushion is respectively associated. In this way the use of braided elastic bands is avoided which, as well as making the production process longer and more complex, do not guarantee functioning stability over time.

Moreover the panel is provided with a first end edge pivoted to the first frame or respectively to the second frame by pivoting means, and with a second end edge, opposite the first end edge, in proximity to which suspension means are suitable to act in order to control the oscillation of the panel around the pivoting means.

In this way, at the moment when the user sits down on the seating cushion, the panel follows the movement of the user, adapting itself to his weight.

A similar effect is achieved with regard to the backrest cushion, and the panel to which it is associated.

According to another feature of the present invention a padding system is associated to the support structure, comprising the seating cushion and the backrest cushion made in a foam material and respectively having a first thickness and a second thickness. Moreover, at least one of either the seating cushion or the backrest cushion is provided inside the first thickness and/or the second thickness with a closed recess defining a zone of differentiated flexion.

The present invention also concerns a method to make an ergonomic seating element as described above and provides:

- to arrange, for each of the seating cushion and backrest cushion, at least a first portion and a second portion which can be coupled with respect to each other along at least an interface surface;

- to make, in the first portion of the seating cushion and of the backrest cushion, at least a recess open toward the interface surface;

- to couple, along the interface surface, the first portion and the second portion in order to close the recess inside the thickness of the seating cushion and the backrest cushion.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a cross section view of a seating element, such as a sofa, an armchair or suchlike, according to the present invention;

- fig. 2 is a view of a detail of fig. 1 according to a first variant;

- fig. 3 is a view of a detail in fig. 2 according to a second variant;

- fig. 4 is a lateral view of a padding system of the seating element in working condition, that is, under the effect of the weight of a user;

- fig. 5 is a lateral view of a padding system in a condition not stressed by a user;

- fig. 6 is a schematic representation of a combination of figs. 4 and 5 with respective exploded views of some parts of the seating element, highlighting the shapes of parts removed from the padding according to the present invention;

- fig. 7 is a lateral view of the seating element of fig. 5 with other components;

- fig. 8 is a plan view of one of the other components shown in fig. 7.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DETAILED DESCRIPTION OF SOME FORMS OF EMBODIMENT

With reference to fig. 1 , an ergonomic seating element according to the present invention, in this case an armchair, is indicated in its entirety by the reference number 10 and comprises a support structure 50, or frame, usually made of wood, to which a seating cushion 1 and a backrest cushion 2 are associated in order to define a seat for the user.

The support structure 50 comprises a first framework 51 , disposed horizontally in use, and a second framework 52, disposed substantially vertical in use, and solidly associated to the first framework 51.

The first framework 51 comprises a bottom panel 53 to which support feet 54 of the support structure 50 are associated, and a vertical upright 55 connected to the bottom panel 53 and disposed on the opposite side with respect to those in which the second framework 52 is associated.

A support panel 57, suitable to support the seating cushion 1, is also associated to the first framework 51.

In particular, the support panel 57 has a first end edge 58 pivoted in correspondence to the free end of the upright 55, and a second end edge 59, opposite the first end edge 58, in proximity to which suspension means 60 are suitable to act.

Pivoting means 61 are provided between the upright 55 and the support panel 57, which allow the support panel 57 to rotate around the first end edge 58.

In a non-stressed condition of the support panel 57, that is, when the user is not sitting on the seating element 10, the support panel 57 is inclined toward the bottom panel 53 and with respect to the horizontal, by a first angle a comprised between 4° and 30°, advantageously between 4° and 20°.

The pivoting means 61 extend for the entire length of the seating element 10, even if, in other forms of embodiment, more pivoting means 61 can be provided, disposed at intervals with respect to each other along the longitudinal extension of the support panel 57.

The suspension means 60 in this case comprise a helical spring 62, to which a support element 63 is associated which provides to support the helical spring 62. In other forms of embodiment the suspension means 60 comprise damping devices such as pneumatic or hydraulic actuators, cup springs, leaf springs, or other devices suitable to the purpose.

The support element 63 is solidly associated to the bottom panel 53.

The helical spring 62 is attached at one of its ends to the support element 63, and the support panel 57 rests on its other end.

The end of the helical spring 62, on which the support panel 57 rests, is solidly connected to a support plate 65 which is interposed between the helical spring 62 and the support panel 57 and provides an equal distribution of the stresses.

In a first form of embodiment it can be provided that the support panel 57 rests only against the support plate 65. in this way allowing the latter to move, even just a little, during the stress actions, assisting the rotation of the support panel 57.

In accordance with another form of embodiment, the support plate 65 is solidly associated to the support panel 57, for example by threaded connections. This solution allows to ensure the positioning of the helical spring 62 with respect to the support panel 57 and the latter, when under stress, is subjected to an inflexion effect to follow the inclination imposed by the support panel 57.

The use of a spring of the helical type is particularly advantageous given the high bearing capacity when under compression which they are able to support, compared to other types of elastic springs.

Simply to give an example, the helical spring 62 has a length comprised between 8 cm and 12 cm.

The suspension means 60 are distributed at several points along the longitudinal extension of the support panel 57 so as to allow homogeneous support when a user is seated.

The suspension means 60 allow an angular excursion of the support panel 57 by an angle β with an amplitude comprised between 4° and 30°, advantageously between 4° and 20°.

In another form of embodiment (fig. 2) the suspension means are indicated by the reference number 160, and unlike what has been described with reference to fig. 1 , comprise a damper device 170 provided with a first tubular body 171 and a second tubular body 172 suitable to be coaxially inserted inside the first tubular body 171.

Between the first tubular body 171 and the second tubular body 172 a chamber 175 is defined, substantially closed and inside which a helical spring 162 is disposed.

The first tubular body 171 and the second tubular body 172 can slide axially with respect to each other. At the moment when the suspension element 160 is stressed, because of the weight of the user, the air inside the chamber 175 provides to damp the rapid oscillation of the support panel 57 which would occur if only the one helical spring 162 were present.

At the moment when the suspension means 160 are no longer stressed, the helical spring 162 provides to return the support panel 57 into its inactive position.

The second tubular body 172 is provided, in its upper end, with a pivoting element 176 to which a slider 177 is pivoted.

The slider 177 is suitable to slide along a first guide 178 solidly associated to the lower surface of the support panel 57.

The guide 178, the slider 177 and the pivoting element 176 allow the support panel 57 to freely pivot horizontally around the pivoting means 61 .

The suspension means 160 can be attached to the bottom panel 53 in a variable position along the longitudinal extension of the latter.

In particular, a second guide 179 is attached to the bottom panel 53, onto which the suspension means 160 are attached in the desired position, using attachment means 1 80 such as screws, pins and bolts.

The positioning of the suspension means 160 along the second guide 179 allows to modify the suspension effect of the support panel 57. In this way it is possible to provide an adjustment of the damping and suspension performed by the support panel 57 both in relation to the type of product that is being made and also in relation to the specific needs of the final user who will use the seating element 10.

In accordance with another form of embodiment (fig. 3) the suspension means are indicated by the reference number 260 and, as described above, comprise the damper device 170 with functions and properties similar to that described with reference to fig. 2. In this case too, it is provided that the suspension means 260 can be positioned in several positions along the longitudinal extension of the second guide 179.

A second helical spring 182 is attached to the second tubular body 172, in correspondence to its free end, on which the support panel 57 rests with its lower surface.

This solution allows to achieve a double suspension effect of the support panel 57, a first elastic suspension effect conferred by the helical spring 182 and immediately perceptible by the user, and a second damped suspension effect conferred by the damper device 170 and which provides to limit the immediate horizontal pivoting effect of the single spring 162.

The second framework 52 is provided with a bearing panel 66 on which the backrest cushion 2 is disposed during use.

The bearing panel 66 is inclined with respect to the vertical by an angle γ comprised between 4° and 30°.

Both the support panel 57 and the bearing panel 66 are made of a sufficiently rigid material, and are provided with a plurality of through holes 67 as shown in fig. 8.

The through holes 67 allow to confer greater transpirability to the seating element 10, preventing the formation of humidity, molds or suchlike.

Advantageously, the support panel 57 and the bearing panel 66 are made of wood, multilayered for example, without being at odds with the tradition of handcrafted or semi-handcrafted manufacturing of sofas and armchairs.

The rigidity of the panels 57 and 66 allows on the one hand to guarantee a constant behavior of the padding over time, but also to obtain products having similar or very close mechanical characteristics.

More precisely, it is not necessary, as provided in the state of the art, to prepare concave containing tanks, because the padding is self-contained when it rests on a flat surface. It is also possible to eliminate an assembly station of the elastic bands, reducing production costs. Indeed, the support panel 57 and the bearing panel 66 can be assembled directly during the manufacture of the support structure 50.

A padding system is attached to the first framework 5 1 and to the second framework 52, which comprises at least the seating cushion 1 and the backrest cushion 2 to support the lumbar and humeral-scapular regions.

The backrest may possibly be made in two different portions, one, lower, intended for the lumbar zone, and the other, upper, intended for the humeral- scapular zone.

Each cushion of the seat 1 and of the backrest 2 comprises recesses inside the respective thicknesses S I and S2. Inside the thickness means that the recesses do not emerge from the surfaces of the cushions, that is, the recesses are surrounded by the material of which the cushions are made.

The recesses preferably extend for the entire w idth of the cushions, that is, they have a longitudinal development in the direction perpendicular to the sheet of the boards relating to figs. 4 to 7, attached to the present description. In other words, the recesses extend transversely to the backbone of a user or transversely to the lower limbs of the user seated on the sofa or armchair.

Having defined a direction upward H (fig. 5) and forward F associated to a sofa or armchair, the transverse direction is perpendicular to both the directions upward H and forward F.

To simplify the making of the recesses each cushion 1 and 2 is made with two portions, each having an extension equal to that of the impression of the whole cushion, that is, the larger surface of the cushion. The two portions are positioned one above the other and attached lengthwise to each other to define a respective common interface surface I I , 12 transverse to the thicknesses S I and S2 of the cushions 1 and 2. One or both the portions are worked, that is, they comprise recesses in correspondence to the common interface surface between the two portions.

With reference to the cushion of the seat 1 , this comprises an upper portion 12 and a lower portion 1 1 . At least the part 13' (fig. 6) is removed from the lower portion 1 1 leaving a corresponding first recess 13 (fig. 5). The first recess 13 has substantially an open U shaped section, with the concavity facing toward the user, that is, toward the interface surface I I , in common with the upper portion 12 of the seat 1. In particular, the first recess 13 is made starting from the interface surface I I .

The first recess 13 is made, with its center line N at about 16cm-22cm with respect to the rear edge of the cushion 1 , that is, to the edge adjacent to the backrest cushion 2. This distance is optimal, since it substantially corresponds to the resting point of the user's ischiatic bones or coccyx.

If the seating cushion 1 has a length L of about 50 cm or less from the rear edge to the front edge, that is, the one opposite the rear one, further recesses are not needed. Otherwise, for longer lengths, it is necessary to make a second recess 14, corresponding to the part 14' (fig. 6) of removed material, in correspondence to the front edge, which allows the seating cushion 1 to limit its thrust against the popliteal cavity and the neuro-vascular fascicle of haematic and lymphatic vascularization of the user.

The second recess 14 has a closed U shape with a much smaller width than the first recess 13. The second recess 14 is also made starting from the interface surface I I with the concavity turned upward H, that is, toward the user. Preferably the first recess 13 (fig. 5) has a width L 13 comprised between 15 and 35 cm with a preferred value of about 26 cm and a height, according to the thickness S I of the seating cushion 1 , comprised between 3 and 7 cm with a preferred value of 4.5 cm.

The sizes of the first recess 13 can be varied in relation to the mechanical characteristics of polyurethane and in any case of the material used to make the seating cushion 1 .

Preferably the second recess 14 (fig. 5) has a width L 14 comprised between 7 and 1 1 cm with a preferred value of 9 cm and a height, according to the thickness S I of the seating cushion 1 , comprised between 3 and 7 cm with a preferred value of 5.5 cm.

The sizes of the second recess 14 can vary in relation to the mechanical characteristics and in any case of the material used to make the seating cushion 1 and in relation to the length L of the seat.

Advantageously, it is possible to differentiate, in a simple and economic way, the rigidity of the seating cushion 1 , supporting more exposed parts of the skeletal apparatus with softer zones and vice versa. Advantageously, this allows to distribute in a more comfortable way the supporting thrust of the seating cushion 1 against the skeletal apparatus. Therefore the padding serves to create differentiated zones of flexion on the backrest cushion 2 and on the seating cushion 1 in relation to the areas where a more rigid support is needed or on the contrary a softer and more yielding support, that is, where fat and muscle leave bigger portions of the skeletal apparatus exposed.

The backrest cushion 2 comprises a front portion 22 and a rear portion 21 intended to be attached to each other along a common interface surface 12. At least the part 23 ' (fig. 6) is removed from the rear portion 21 to define a corresponding third recess 23 (fig. 6). The third recess 23 also has a substantially open U shape section, with the concavity facing forward, that is, toward the back of the user and toward the interface with the front portion 22 of the backrest 2.

The third recess 23 is made in correspondence to the scapular-humeral bones of the user.

Preferably the third recess 23 (fig. 5) has a width L23 comprised between 15 and 25 cm with a preferred value of 20 cm and a height, according to the thickness S2 of the backrest cushion 2, comprised between 3 and 7 cm with a preferred value of 5 cm.

A fourth recess 24, corresponding to the removed part 24', is made in correspondence to the lumbosacral bones. An intermediate point M, between the third 23 and the fourth 24 recesses, is positioned at about 18-22 cm from the edge of the backrest 2 adjacent to the seating cushion 1.

The fourth recess 24 also has a closed U shape with an extension along the interface surface 12 which is much smaller than the third recess 23.

The fourth recess 24 also has its concavity facing forward F and like the third recess 23 is made starting from the interface surface 12.

Preferably the fourth recess 24 (fig. 5) has a width L24 comprised between 10 and 15 cm with a preferred value of 10 cm, and a height, according to the thickness S2 of the backrest cushion 2, comprised between 3 and 7 cm, preferably about 5 cm.

The sizes of the third recess 23 and the fourth recess 24 can be varied in relation to the mechanical characteristics of polyurethane and in any case of the material used to make the backrest cushion 2.

The above-mentioned preferred sizing values of the recesses are particularly optimal for one material, for example polyurethane having the following mechanical characteristics:

Density: 35 kg/m3 Compression force CV40 (En ISO 3386- 1 ): 3.0 kPa

Carrying capacity:

Compression load resistance at 25% (+/- 15%): 98N

Compression load resistance at 40% (+/- 15%): 128N

Compression load resistance at 65% (+/- 15%): 250N

Resistance to traction

Ultimate tensile strength: 100kPa

Minimum elongation: 180%

A polyurethane having such characteristics is commonly indicated by the acronym 35SS.

On the other hand, in relation to the interval values conferred to the sizes of the first 13, second 14, third 23 and fourth 24 recesses and to the thickness of the seating cushion 1 and backrest cushion 2, materials with different mechanical characteristics can be used, distributed in this way:

Density: 25-45 kg/m3

Compression force CV40: 1.3 - 6.3 kPa

Carrying capacity:

Compression load resistance at 25% (+/- 15%): 38- 190N

Compression load resistance at 40% (+/- 15%): 53-260N

Compression load resistance at 65% (+/- 1 5%): 1 10-5 10N

Resistance to traction

Ultimate tensile strength: 70 - 1 10 kPa

Minimum elongation: 100% - 180%

As the Compression load resistance, density and thickness of the seating cushion 1 and backrest cushion 2 increases, it is necessary to increase the sizes of the first 13, second 14, third 23 and fourth recess 24, moving within the above intervals.

Each of the possible combinations of sizes of the first 13, second 14, third 23 and fourth 24 recesses and the mechanical characteristics of the material used for the padding, allows to have cushions, both seating 1 and backrest 2, which are self-containing, that is, able to keep a respective controlled deformation without the aid of external constraints.

It is, moreover, preferred that the first 13, the second 14, the third 23 and the fourth 24 recesses are 3-4 centimeters apart from the surface intended to come into contact with the support panel 57 and the bearing panel 66.

In other words, the upper portion 12 and the rear portion 21 having a thickness of material of at least 3-4cm for example, polyurethane, are associated respectively to the lower portion 1 1 and to the front portion 22.

It is therefore obvious that preferred cushions thus obtained, according to the present invention, have thicknesses greater than 9- 10 cm, and are therefore the high thickness type.

According to another feature of the invention the two portions 1 1 , 12, 21 , 22 of each seating cushion 1 and backrest cushion 2 can be made of different materials. It can be provided, for example, that the upper portion 12 and the front portion 22, that is, those intended to go into contact with the skeletal apparatus of a user, are made of material having open cells, so as to improve ventilation.

According to another feature of the invention, the sofa and armchair seats are much wider than the seats in a car; therefore, the reduced enveloping effect of sofas and armchairs does not allow to know exactly, a priori, the point of contact of the coccyx and ischiatic bones on the cushion seating. For this reason, a recess having the above-mentioned U section with a longitudinal development transverse to the lower limbs or the backbone is optimal in order to satisfy and resolve the aforementioned problems of improving the ergonomics of the products obtained.

According to another feature of the invention, the recesses, above all the first 13 and the fourth 24 can each have a not perfectly symmetrical shape, but rather can provide a greater aperture of the "stem" of the U subject to a reduced sinking represented by the load curve shown by a dotted line C.

Advantageously, the shoulders are supported by the backrest cushion 2 rather than surrounded, avoiding excessive pressure in correspondence to the shoulder blade. Moreover, the intermediate point M, corresponding to the lumbar region, supports the whole back transversely and longitudinally. In the lumbar seating, the spine is alone in supporting and balancing the body mass above, such as the head, the shoulders, the arms and obviously the chest.

It is also preferred that the backrest cushion 2 forms an angle comprised between 90° and 1 10° with the seating cushion 1. The external shape of the seating cushion 1 or the backrest cushion 2 can be varied in relation to stylistic and aesthetic needs, and therefore the present invention does not in any way affect the original design of a sofa or an armchair.

Furthermore, the person of skill in the art knows what is meant by high thickness cushions, and has a precise idea of the minimum thickness which these must have.

A preferred method for manufacturing a padding system for sofas and armchairs, in conformity with the present invention, comprises the following steps:

- arranging the first portion 1 1 , 21 of the at least two portions of each seating cushion 1 and backrest cushion 2;

- making at least a recess 13, 14, 23, 24 on at least an interface surface I I , 12 of the first portion 1 1 , 21 in correspondence to a part intended to be in contact with the most exposed parts of a skeletal apparatus;

- arranging the second portion 12, 22 of the at least two portions of each seating cushion 1 and backrest cushion 2,

- connecting the first 1 1 , 21 and the second portion 12, 22 along the interface surface I I , 12, so that the recess 13, 14, 23, 24 is within the thickness S I , S2 of the cushion.

It is clear that modifications and/or additions of parts may be made to the seating element such as a sofa, an armchair or suchlike as described heretofore, without departing from the field and scope of the present invention.

Indeed, even though the present invention has been described presupposing that the suspension means 60, 160, 260 are applied only to the support panel 57 of the seating cushion 1 , it is not excluded that a similar application can also be provided for the bearing panel 66.

In this case the bearing panel 66 is therefore pivoted to the second framework 52 in correspondence to a peripheral edge and, in correspondence to the other peripheral edge, disposed in proximity to the seating cushion 1 , the suspension means are suitable to act. In this solution too, all the forms of embodiment described for the suspension means associated to the support panel 57 can be provided.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of seating element such as a sofa, armchair or suchlike, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.