FIELD OF THE INVENTION

Generally, the present invention relates to seating arrangements. Particu larly, however not exclusively, the invention pertains to an adjustable chair mechanism.

BACKGROUND

Ergonomic adjustable seating solutions commonly comprise office chairs that have adjustable sitting height and seat inclination arrangements. On the other hand, another typical solution for an ergonomic seating arrange ment is a saddle chair which may also comprise an adjustable height. The saddle seats usually aim for providing for an improved seating posture when compared to traditional flat stools and seats.

However, as is also the case with standing tables, the users may often wish to alternate between positions. However, the typical saddle and stool or flat seat arrangements exclude each other regarding the sitting posture. Excluding the sitting position into only the saddle seating posture may cause discomfort for many and it may even prove to be impossible for ex tended periods of time.

Some specific prior art solutions have aimed to provide for a seating mechanism that may change between saddle-like and flat positions. These solutions typically utilize means such as linear springs and gas springs as well as separate mechanical support arms to change the seating position.

SUMMARY OF THE INVENTION

The objective of the embodiments of the present disclosure is to at least al leviate one or more of the aforementioned drawbacks evident in the prior art arrangements particularly in the context of adjustable seating arrange ments. The objective is generally achieved with a chair mechanism in ac cordance with the present invention. The primary advantage of the present invention is that it allows for easily adjusting a seat between flat and saddle-like positions with an actuation mechanism that is simple in terms of the working principle and number of parts associated thereof Further advantage of the present invention is that it enables the saddle-like position to be in a higher sitting position than the flat position, which is beneficial since users usually prefer a saddle seat to be in a higher sitting position than a flat seat. Further, this allows for more height range of adjustment for the chair. One objective technical problem to be solved with the invention is how to arrange a chair mechanism that may be adjusted to provide a seating ar rangement that may be actuated between at least a saddle-like position and a planar seating position. In accordance with one aspect of the present invention chair mechanism for an adjustable seat comprising a flat spring mechanism connectable to or integrated as an underside of a seat part, which seat part comprises an adjust able structure, such that at least part of said seat part is con formable to the movement of the flat spring mechanism, a base part under the flat spring mechanism, comprising a separate part or being a part of the flat spring mechanism, which base part may be arranged to support the flat spring mechanism and in relation to which the flat spring mecha nism can be adjusted, wherein said flat spring mechanism is arranged to move at least between two positions comprising o a first position when the flat spring mechanism is in a rest position and the flat spring mechanism forms the seat part into a saddle-like shape wherein the center of the seat part is elevated in relation to the sides of the seat part, and o a second position when the flat spring mechanism is in a flattened position by application of force against the flat spring mechanism, in which second position the flat spring mechanism forms the center and sides of the seat part into a flat shape. Further embodiments of the present invention are presented in the depend ent claims. Some exemplary applications for the present invention comprise ergonom ic work and office chairs, boat seats and dentist chairs.

As briefly reviewed hereinbefore, the utility of the different aspects of the present invention arises from a plurality of issues depending on each par- ticular embodiment.

The expressions “planar” and “flat” are used essentially interchangeably. The position meant by the terms “planar” and “flat” need not be complete ly level or otherwise completely “flat” and should be understood as a flat- like position in relation to a significantly more three-dimensionally shaped saddle-like position.

The expression “tilt” (and different word forms of said expression) is used to refer to the change in angle between two objects regardless of how it is physically attained. I.e. the expression is meant to encompass various ways of attaining the function of changing angle between two objects, are as or zones, such as by bending or swiveling two objects, areas or zones in relation to each other or by facilitating hinge-like movement between the objects, areas or zones.

The term “saddle-like” is used to refer to the position of the seat wherein the actual three dimensional shape of the chair mechanism and seat thereof is not limited to a shape of a saddle but which shape may optionally be tubular or any preferred three dimensional shape attained via the resulting shape of at least one middle part, area or zone in relation to which out lines, objects, areas or zones outlining the at least one middle part are curved or tilted in relation to. The term “saddle-like” may further encom pass three-dimensional seat shapes, such as a “jockey seat” known gener ally in the context of boat seats.

The expression “a number of’ may herein refer to any positive integer starting from one (1). The expression “a plurality of’ may refer to any positive integer starting from two (2), respectively. The term “exemplary” refers herein to an example or example-like feature, not the sole or only preferable option. Different embodiments of the present invention are also disclosed in the attached dependent claims.

BRIEF DESCRIPTION OF THE RELATED DRAWINGS Next, some exemplary embodiments of the present invention are reviewed more closely with reference to the attached drawings, wherein

Figs la, lb, lc, Id and le illustrate different views of an embodiment in accordance with the present invention in a saddle-like position, Figs. 2a, 2b, 2c, 2d and 2e illustrate different views of an embodiment in accordance with the present invention in a flat position.

DETAILED DESCRIPTION OF THE EMBODIMENTS Figs la, lb, lc, Id and le illustrate different views of an embodiment in accordance with the present invention in a saddle-like position.

The chair mechanism (100) comprises a flat spring mechanism (102) con nectable to or integrated as an underside of a seat part (104). The flat spring mechanism (102) in this embodiment comprises a leaf spring -type spring with a U-shaped profile attached to four points on the underside of a seat part (104). In alternative embodiments a plurality of flat spring mechanisms may be used, which may be connected in series, side by side or in top of each other. The one or more flat spring mechanisms (102) may be attached one or more points on the opposite sides (104b) of the under side of the seat part (104), as depicted. In accordance with one embodi ment, the flat spring mechanism (102) has a curvilinear profile with sides tilted in relation to the middle are of the spring when in resting position. This type of flat spring may be flattened by applying force on the spring wherein the sides of the spring and the middle part exert a counterforce and desires to return to the resting position. The flat spring mechanism (102) is arranged to produce a first position when the spring mechanism (102) is in a non-tensioned position such that the center of the seat part (104) is elevated in relation to the sides of the seat part (104) conforming into a saddle-like shape, and further arranged to be flattened to a second position by applying force on the spring mechanism (102), in which sec ond position the seat part (104) conforms into a flat shape. Hence, the seat part (104) conforms naturally to a saddle-like shape when the spring mechanism (102) is released and the seat part (104) may be forced into a flat shape by for example sitting on the seat part (104) when the spring mechanism (102) is not locked or otherwise held in place. Therefore, the spring mechanism (102) may be arranged to force the middle part (104a) of the seat part (104) to move upwards to the saddle-like position wherein the weight of a user may be used to counter the spring force and move the middle part (104a) down and a locking mechanism may be used to keep the middle part (104a) in the flat position in relation to the side parts (104b). Alternatively, the saddle-like shape may be natural state of the seat part (104) at rest in which case the spring mechanism (102) is used to ten sion the seat part (104) into a flat position by pressing against the seat part (104) and the spring mechanism (102) therebelow.

Hence, the flat spring mechanism (102) may encompass various different designs wherein the spring mechanism (102) may comprise one or more springs, which may be integrated together. The flat spring mechanism (102) may specifically be a non-coil flat spring mechanism. The flat spring mechanism (102) may have a curvilinear profile at resting position as depicted in the drawings, which profile may be closed or open, which allows the spring to be tensioned and flattened by pressing the spring to gether. The flat spring mechanism (102) may comprise a leaf-spring type design having one or more parts connected or laminated in a curvilinear, such as semi-elliptical or elliptical, shape. Further feasible designs for the flat spring mechanism (102) may encompass such cross-sectional profiles as U-type, V-type, and various polygon shapes, including but not limited to hexagonal, octagonal and decagonal shapes. Further, such polygon shapes need not be symmetrical. In the aforementioned designs the flat spring mechanism should hence be understood as having a raised part and curved or angled sides in relation to which the middle part and sides the flat spring mechanism may be pressed against. Hence, it does not matter whether the spring design is cross-sectionally open or closed profile as long as it achieves the function of being able to be compressed in the manner explained. The flat spring mechanism (102) may comprise one or more materials or functional parts, such as overlayed materials, which are elastic in the sense that the spring may be tensioned such that after release the spring returns to its original shape prior to tensioning. An example of a flat spring mechanism with varying amount and shape of parts is the leaf spring. The The shape, connection with the base part (106) and seat part (104), and material of the spring mechanism (102) may be selected such as to produce various different spring characteristics to the spring mechanism (102), such as the spring constant of the spring mechanism (102). Alt hough not explicitly depicted, the spring mechanism (102) may be housed within a frame.

The flat spring mechanism (102) may comprise or be arranged on a base part (106), which may comprise a plate or such flat surface, or a part of the spring mechanism structure (102), such as a flat part of the spring mecha- nism (102), which part of the spring mechanism (102) or the base part (106) may be fixed on or at a seat post, swivel mechanism or other chair mechanisms with various functions. Alternatively, the base part (106) may embody any element or mechanism on which the actuation mechanism may be attached to. E.g. the swivel mechanism, seat post or other chair mechanism part may comprise or constitute a part that is used as the base part (106).

The seat part (104) is preferably attached over the spring mechanism (102) to constitute a chair or body for a chair with an adjustable seat. Altema- tively, the seat part (104) may be a part of the spring mechanism (102). The seat part (104) may comprise a single piece which is deformable to the first position and the second position. Alternatively, the seat part (104) may comprise at least functionally different middle part (104a) and one or more side parts (104b), which allow movement or non-permanent defor- mation in relation to each other. The middle (104a) and side parts (104b) may comprise a plurality of individual solid parts connected to each other or the seat part (104) may be essentially a single structure with two or three parts distinctive via their shape, material or thickness. The seat part (104) may also comprise at least one middle part (104a) and at least one side part (104b), such that the seat part (104) comprises one solid part that is adjustable such that the whole seat part (104) or parts thereof may be adjusted between at least two positions comprising an essentially flat- shape and saddle-like shape. In the aforementioned case, the middle part (104a) and the at least one side part (104b) may be defined by functionally separate areas of one single seat part (104) in which at least one side areas of the single seat (104) part are tiltable in relation to at least one middle area of the single seat part (104). The seat part (104) structure of at least one middle part (104a) and at least one side part (104b) allows for the ad justment of the seat part (104) between a flat stool shape and a saddle-like shape. The seat part (104) may comprise three parts, such as that there are two side parts (104b) and a middle part (104a) in between said side parts (104b).

The seat part (104) must be such that is forms a saddle-like form when the middle part (104a) is elevated and consequently as the at least one side part (104b) is tilted in relation to the middle part (104a). This may be at tained via a wide array of different shapes and/or materials, such an essen- tially triangularly shaped or rectangularly shaped middle part (104a) with two arched side parts (104b) or an essentially single square-like piece as depicted. The seat part (104) may also comprise hollow spaces between at least one side part (104b) and the middle part (104a) as depicted. By the angled resting position profile of the flat spring mechanism (102) the seat part (104) will have a first position in a saddle-like position. The seat mechanism (100) may further comprise a support mechanism (108) between the underside of the seat part (104) and the spring mechanism (102) or the base part (106) to support and/or lock the spring mechanism (102) in a position relative to the seat part (104). The support mechanism

(108) may comprise for example a sliding support arm mechanism be tween the seat part (104) and the spring mechanism (102) or the base part (106) to support and/or lock the spring mechanism (102) at least in the first position and/or second position, as depicted. Such mechanism may be based on a support arm fixed either at the seat part (104) or at the spring mechanism (102) or base part (106) and accordingly from the other end be able to move, such as by sliding, and be locked in a position for example by the type of latch locking mechanism as presented. Alternatively, a scis sor mechanism between the seat part (104) and the spring mechanism (102) or the base part (106) to support and/or lock the spring mechanism

(102) in at least the first position and/or second position. Similarly to the sliding arm the scissor mechanism may be at least operationally connected between the base part (106) and the seat part (104) to provide additional support for the seat part (104) in addition to the spring mechanism (102). The support arms of the scissor mechanism may be arranged to move syn chronously when the middle of the seat part (104) is lifted by the spring mechanism (102) such that the support arms slide in relation to the base part (106). The support arms may also be arranged to move via guides or tracks facilitated via a frame of the actuation mechanism. The scissor mechanism may be connected to the underside of the seat part (104) via by a locking mechanism or a latch, which locks or otherwise limits the verti cal movement of the seat part (104) in relation to the base part (106). A further alternative is to use a piston mechanism between the seat part (104) and the spring mechanism (102) or the base part (106) to support and/or lock the spring mechanism (102) at least in the first position and/or second position. A further alternative is to use an A-shaped or X-shaped mechanism, which may be seen as variation of the scissor mechanism. The support mechanism (108) may comprise various other alternative designs having the same described function of being able to lock the flat spring mechanism (102) in at least the first position and/or second position. It is clear that the spring mechanism (108) may be set in various other posi tions between the first and second position, which may provide more ad- justability to the chair mechanism (100), such as a further number of ad justable seat positions and shapes. Further function of the support mecha nism (108) may be to provide the chair mechanism (100) more stability and support. The chair mechanism (100) may comprise a home position, such as the first position, to which position the chair mechanism (100) returns to when it is not locked or otherwise set in either saddle-like or flat position. The spring mechanism (102) and force exerted thereof may be used to alternate the position of the chair from a flat position to a saddle-like position and vice versa where the spring mechanism either actuates movement to flat ten or bend the seat part (104) depending on the type and setting of the chair mechanism (100) and specifically the spring mechanism (102).

Figs. 2a, 2b, 2c, 2d and 2e illustrate different views of an embodiment in accordance with the present invention in a flat position.

As depicted, the chair mechanism (100) may be adjusted such as to form a flat shape and corresponding seating position for the user. Moving into the second position, i.e. flattening the seat part (104), may be attained by opening the locking mechanism and applying force on the seat part (104) to overcome the countering force of the spring mechanism (102). In some embodiments the chair mechanism (100) may allow for adjusting between more than two seating positions e.g. via a locking mechanism at, or func tionally connected to, the spring mechanism (102) to stop movement at predetermined points. The adjustment may be stepwise or stepless. This way, different ergonomic seating positions may be achieved for different physiological structures and therefore different postures of users. Howev- er, the chair mechanism (100) may be also made simple such that it may be only locked to a first position and second position wherein the other is a flat position and the other is a saddle-like position.

The chair mechanism (100) may also be integrated or retrofitted to a common seat post, swivel chair mechanism, or the like, to combine the functionalities and/or other adjustment means of the existing swivel chairs with the adjustable chair mechanism (100). In some embodiments the spring mechanism (102) can also be integrated with a chair pneumatic cyl inder, such as the chair post cylinder, or a swivel mechanism wherein a part of the cylinder or swivel mechanism comprises or constitutes the base part (106). Even further, the adjustable chair mechanism (100) may com prise or be integrated with an upholstery on the top said of the seat part (104). Therefore, the seat part (104) may comprise or constitute an actual seat for a user or the seat part (104) may comprise or constitute the part on which a separate seat is arranged, such as by arranging additional materi als and/or structures thereon.

The scope of the invention is determined by the attached claims together with the equivalents thereof. The skilled persons will again appreciate the fact that the disclosed embodiments were constructed for illustrative pur poses only, and the innovative fulcrum reviewed herein will cover further embodiments, embodiment combinations, variations and equivalents that better suit each particular use case of the invention.