NL2016701A - Adjustable size work chair, assembly comprising said chair and an adjustable size work table, method for assembling said chair and table, and use of the chair and the assembly. - Google Patents

Abstract

The present invention concerns the field of adjustable size furniture, and more specifically adjustable size work chairs and assemblies comprising said chair and an adjustable size table. In particular, the invention provides an adjustable size work chair with predetermined seat heights and predetermined seat depths of the chair such that the seat height and the concomitant seat depth are adjustable to positions with a predetermined ratio between the seat height and depth. Moreover, the invention provides an assembly comprising the adjustable size work chair and an adjustable size work table. In addition, the invention provides a method for assembling the chair and the table. Furthermore, the invention provides the use of the chair and the assembly in a classroom or in an office.

Description

ADJUSTABLE SIZE WORK CHAIR, ASSEMBLY COMPRISING SAID CHAIR AND AN ADJUSTABLE SIZE WORK TABLE, METHOD FOR ASSEMBLING SAID CHAIR AND TABLE, AND USE OF THE CHAIR AND THE ASSEMBLY

TECHNICAL FIELD OF THE INVENTION

The present invention concerns the field of adjustable size school furniture, and more specifically adjustable size work chairs and assemblies including said chair and an adjustable size work table, for use at school or in the office. In particular, the invention provides an adjustable size work chair with predetermined and fixed seat heights and concomitantly predetermined and fixed seat depths of the work chair such that the seat height and the concomitant seat depth are adjustable to positions with a predetermined ratio between the seat height and seat depth. Moreover, the invention provides an assembly including the adjustable size work chair and an adjustable size work table. In addition, the invention provides a method for assembling the work chair and the work table. Furthermore, the invention provides the use of the work chair and the assembly in a classroom or in an office.

BACKGROUND OF THE INVENTION

At school, pupils or varying age, and thus most often a very wide varying length, or size, regularly follow their education jointly. Thus, pupils with varying physical size are properly seated at one and the same school. As a result, in schools a series of work chairs having incremental heights are required to cover a wide range of children lengths. Basically the same holds true for an accompanying series or work tables having incremental heights, at which the pupils are seated.

Since year by year the numbers of pupils have certain physical sizes differ over the common lengths, schools regularly have more chairs and tables or every size than the number of pupils, in order to be able to adapt to these varying numbers. Even within a school year, pupils may growth that much requires a larger size chair and table, further making the availability of a stock piled range or spare chairs and spare tables having all sizes a necessity for the school. In addition, chairs and tables may require (temporary) replacement due to partial or complete damage. Of course, stock piling the temporarily superfluous chairs and tables provides the schools with the common and well-known problem or struggling with limiting space available in the school building.

In Europe, for example, the European Standard prEN1729 specifications for a range of work-chair seat heights and accompanying seat depths, and work table heights for school furniture suitable for adequate seating pupils 93 cm up to 207 cm or length. This Standard subdivides the heights and depths of the school furniture in seven ranges or pupil lengths. Thus, a school will require work chairs and work tables having relatively small heights, as well as a range of chairs and desks with increasingly larger heights, in order to adequately cover seating the full range or pupil lengths. These numbers of chairs and tables having different dimensions may thus add up to seven for a Europe-based school.

To avoid the requirement for the school to buy separate sets of work chairs and work tables, and their accompanying spare parts, specifically adapted to each of the predetermined range or consecutive pupil lengths individually, adjustable size work chairs are known in the art. In addition, also assemblies or adjustable size work chairs and a work table are known in the art. Such adjustable size work chairs cover two or more of the ranges or pupil lengths. Such work chairs typically have moveable seats and moveable backrests and / or height adjustable chair legs and / or moveable supports for the feet, i.e. height adaptable footboards. Adaptation of the work chair or the assembly including the work chair to the length of a specific pupil requires adjustment of seat height, seat depth, and the height of the seat relative to the height of the work table leaf. Typically, more than one part of the work chair or of the assembly including a work chair requires to be moved in order to achieve said desired adjustment to adapt to the length of a specific pupil. For example, adjustment of the seat, the backrest and the table leaf altogether is required in order to achieve the specific dimensions suitable for seating or a specific pupil. In addition, repositioning or the footboard may be required as well.

For example, in international patent application WO 2010/052504 an adjustable size work chair is provided, as well as a fixed assembly including said chair and a work table connected to the chair via a common frame. Size adjustment of the work chair requires simultaneous movement of both the seat portion and the backrest portion of the work chair.

Thus, the adjustable size work chair in WO 2010/052504 comprises means the frame to move together both the seat portion and the backrest portion of the chair, for the purpose of seat height adjustment and seat depth adjustment. The seat height and seat depth cannot be adjusted without simultaneously adjusting the height of the back rest relative to the support surface supporting the chair. The relative distances between the seat and the backrest portion are predetermined and fixed, without having the ability to adjust the seat height and the seat depth independent from the backrest position. At the highest seat height, also seat depth is maximum, facilitating seating or the tallest pupils.

In one embodiment of application WO 2010/05250, the adjustable size work chair is provided assembled with a work table fixed to the chair via a common frame, said table of the assembly having a table leaf at fixed height relative to the support surface supporting the work chair and the leaf of the work table fixed thereon. Also, the table leaf or said work table in the assembly is positioned at the common frame or the assembly at a fixed distance from the frame portion at which the seat portion and the backrest portion are mounted. At the highest seat height, seat depth is minimal, facilitating seating or the smallest pupils. In order to facilitate seating of the smallest pupils in this configuration of the assembly, also a footboard mounted to the common frame has to be height adjusted separately to its highest position on the common frame.

Adaptation of the assembly including a work chair, a work table and a support for the feet, the size of a specific pupil thus requires movement of the seat portion, the backrest portion and the footboard portion, altogether. Thus, this way, smallest children are seated at high position relative to the support surface, hammering easy getting on and off the chair. For pupils of all lengths, getting on and off the work chairs is furthermore hampered by the table leaf of the work table positioned at fixed distance from the work chair portion of the assembly.

Yet another example of an adjustable size work chair is provided in European patent EP0003882B1. An assembly or an adjustable size work chair and a work table at fixed height is provided. Here, the seat portion of the work chair is moveably mounted to a common frame supporting the seat portion, a backrest portion, a footboard portion, and the table of the work table. Height adjustment of the seat portion concomitantly results in adjustment of seat depth. Adaptation of the assembly to the specific length of a pupil further requires height adjustment of the footboard portion, in addition to required height adjustment of the seat portion. The backrest portion is mounted at a fixed position on the frame relative to the support surface supporting the frame. At the highest seat height, seat depth is minimal, facilitating seating or the smallest pupils. In order to facilitate seating of the smallest pupils in this configuration of the assembly, also the footboard portion has been adjusted separately to its highest position on the common frame. Thus, smallest children are seated at high position relative to the support surface, hammering easy getting on and off the chair. The height of the table leaf of the work table cannot be adjusted relative to the support surface. For all pupils, getting on and off the chairs is further hampered by the table leaf of the work table mounted on the common frame and positioned at predetermined distance from the work chair part of the assembly.

For both assemblies according to patent application WO 2010/052504 and patent EP0003882B1, an assembly consisting of a work chair and a work table mounted at a single common frame at fixed positions relative to each other is not suited for group wise seating more than one pupil at a single work table. Furthermore, use of the work chair separate from the work table is not possible, hampering educational activities.

Hence, a need remains for an adjustable size work chair for school including means for seat height adjustment and means for seat depth adjustment independent from the backrest position, getting seated and getting unseated is less cumbersome for pupils or all lengths. In addition, also a need remains for an assembly including said adjustable size work chair and further included a height-adjustable work table, the position of the work chair relative to the support surface can be selected independent from the position of the work table relative to the support surface. Furthermore, a need remains for a size adjustable work chair and assembly including such a size adjustable work chair and a size adjustable work table, adaptation of the work chair and the assembly to the specific size of a pupil only requires adjustment of the position or a single portion of the work chair or the assembly.

SUMMARY OF THE INVENTION A first aspect of the present invention relates to an adjustable size work chair including a backrest portion, a seat portion and a frame supporting the backrest portion and the seat portion relative to a support surface supporting the work chair, with said backrest portion and said seat portion positioned at a fixed angle relative to each other, the seat portion is moveably arranged with respect to the frame along an adjusting axis and moveable over a seat adjustment range, the adjusting axis makes an angle with the support surface such that moving the seat portion along the direction of said axis in downward direction simultaneously results in moving the seat portion in backward direction, such that the seat height of the chair and the seat depth of the chair are decreased according to a predetermined ratio between the seat height and the seat depth, and vice versa.

The present inventors surprisingly found that only a single part of an adjustable size work chair according to the invention, ie the seat portion, requires to be moved relative to the support surface in order to achieve adjusted dimensions suitable for conveniently seating a pupil having the corresponding matching size. A second aspect of the present invention relates to an assembly including at least one adjustable size work chair according to the invention, preferably 2, 3,4, 6, 8, 9, 10, 12 or said chairs, and at least one adjustable size work table, preferably two tables, said table containing a horizontal leaf portion relative to the support surface and a table frame supporting the horizontal leaf portion relative to said support surface supporting the work table, the height of said work table leaf portion relative to the support surface is adjustable at predetermined positions.

It has further been found that it is advantageous to provide an assembly according to the invention, the table frame includes at least one leg portion including a recess facing the support surface, said recess providing space for at least two human feet positioned underneath the table leaf and next to said lay portion in contact with the support surface. A third aspect of the present invention relates to a method for assembling an assembly including four size adjustable work chairs according to the invention and including one size adjustable work table according to the invention, including the steps of: a) providing two wooden plates with outer dimensions of at least about 122 cm times 244 cm; b) retrieving the portions constituting four chairs and one table from said plates, preferably by sawing; and assembling the chair portions and assembling the table portions such that the four chairs and one table are build and such that the chairs and the table are releasable back into their constituting respective portions. A fourth aspect of the present invention relates to the use of a size adjustable work chair according to the invention or obtainable by the method of the invention and / or use of an assembly including at least one size adjustable work chair according to the invention or available by the method of the invention and at least one size adjustable work table according to the invention or available by the method of the invention, in education such as education in a classroom, preferably in education for children, preferably at school, or use of said chair and / or said assembly in the office.

DESCRIPTION OF THE FIGURES

Figure 1. Adjustable size work chair according to the invention. A. The seat height and the seat depth are minimal, and a footboard is positioned substantially underneath the front of the seat portion. B. The seat height and the seat depth are maximum, and a releasably mounted footboard has been released. The backrest portion is height adjusted relative to the backrest displayed for the seat in A., by releasing the backrest portion, turning the backrest portion 180 °, and fastening the backrest portion again at the same position of the frame.

Figure 2. Adjustable size work chair according to the invention. The seat height and the seat depth are minimal for the hatched seat portion. Positions of two increased seat heights and concomitantly increased seat depths are depicted with dashed lines above the hatched seat portion. Independent from the position of the seat portion, the backrest portion is positioned at two different heights (indicated with the solid line and the dashed line). The seat portion and the backrest portion make an angle with each other or about 97 °.

Figure 3. Exploded view of an adjustable size work table according to the invention.

Figure 4. Side view of an adjustable size work chair according to the invention. Two alternative heights relative to the support surface are visualized with dashed lines for the table leaf and the upper part of the frame supporting the table leaf. The space between the leg portions near the support surface supporting the table is a recess suitable for putting feet or seated individuals at the support surface.

Figure 5. A., B. Wooden plates with contours of portions constituting four size adjustable work chairs and one size adjustable work table according to the invention drawn thereon.

Figure 6. Assemblies of adjustable size work chairs and at least one adjustable size work table according to the invention. Table leafs of the adjustable size work tables of the invention are shown transparently, for clarity reasons (dashed contours). A. Assembly of twelve adjustable size work chairs and two adjustable size work tables according to the invention, the two tables form a square. B. Assembly of eight adjustable size work chairs and a single adjustable size work table according to the invention. C. Assembly of four adjustable size work chairs and a single adjustable size work table according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an adjustable size work chair and an assembly including said chair and an adjustable size work table for e.g. use at school, intended to overcome the various disadvantages known for the current prior art work chairs and assemblies including such chairs. Currently designed adjustable size work chairs have the disadvantage that in order to adjust the size of the chairs more than one portion of the chair have to be moved. For some chairs just more than two portions or a size adjustable chair have been moved in order to adjust its size, i.e. the seat portion, the backrest portion and the footboard portion. Less number and more simple size adjustment technique is aimed for by the current inventors.

Therefore, a first aspect of the present invention relates to an adjustable size work chair including a backrest portion, a seat portion and a frame supporting the backrest portion and the seat portion relative to a support surface supporting the work chair, with said backrest portion and said seat portion positioned at a fixed angle relative to each other, the seat portion is moveably arranged with respect to the frame along an adjusting axis and moveable over a seat adjustment range, using the adjusting axis makes an angle with the support surface such that moving the seat portion along the direction of said axis in downward direction simultaneously results in moving the seat portion in backward direction, such that the seat height of the chair and the seat depth of the chair are decreased according to a predetermined ratio between the seat height and the seat depth, and vice versa.

Since the adjustable size work chair of the invention is for example and preferably intended for use at school for pupils about 4 to 18 years of age, preferably about 4 to 14 years of age, seat height adjustments and simultaneous seat depth adjustments are within the range or heights and depths as prescribed by regulatory standards, with the work chair according to the invention. In addition, regulatory standards also prescribe a fixed ratio between a selected seat height and the accompanying selected seat depth, in order to properly seat a pupil. An example of such a regulatory standard to which the range of possible seat size adjustments or the work chair of the invention is adapted, is the European Standard prEN1729. In order to allow the seat adjustment range and in order to allow the adjustment of the seat height of the chair and the seat depth of the chair to have a predetermined ratio between the seat height and the seat depth, to fall within such regulatory standard, a linear adjusting axis has been proven to be suitable and is preferred according to the invention. Of course, adjusting axis deviating from linear is equally suitable according to the invention, as long as seat heights and seat depths and seat height (:) seat depth ratios according to regulatory standards, are selectable.

Hence, in one embodiment the invention relates to an adjustable size work chair according to the invention, the adjusting axis is a linear axis and the seat height and the seat depth are adjusted at a fixed ratio relative to each other.

For ease of use, the adjustable size work chair or the invention preferably has a seat portion that is moveable over a limited range of seat depths and seat heights. More preferably, for adjustment of the work chair of the invention, it is most convenient when the seat portion is moveable in a stepwise manner, preferably over a limited number of steps, eg 1 to 15 steps, preferably 2 to 6 steps, more preferably 3 steps.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the seat portion is stepwise moveable, preferably stepwise moveable over 3 steps.

Stepwise movability of the seat portion according to the invention is achieved by using any means of releasing the seat portion from the frame supporting the seat portion and again fastening of the seat portion to the frame portion after size adjustment by moving the seat portion from one step to a different step. Suitable means for said purpose are for example Allen bolts, bolts and nuts, such as wingnuts, screws, clamps, screw-thread with a screw-cap, a combination of a hook at the seat portion and notches at the frame portion, or the like.

For reasons of ergonomics and in order to prevent a seated individual from sliding off the work chair of the invention, it is preferred that the seat portion is slightly tilted backwards, relative to the support surface, as part of the invention. The inventors found that an angle between the seat portion or the adjustable size work chair or the support surface or between 1 ° to 6 °, preferably about 3 °, is most convenient according to the invention. Of course, also an adjustable size work chair having a horizontal seat portion relative to the support surface, is part of the invention.

In one embodiment the invention thus relates to an adjustable size work chair according to the invention, the seat portion makes an angle of between 1 ° to 6 ° with the support surface, preferably about 3 °, with the front of the seat portion being the high end of the seat portion and the back of the seat portion being the low end of the seat portion. Alternatively, the seat portion makes an angle or 0 ° with the support surface, according to the invention.

It is part of the invention that the frame of the adjustable size work chair comprises at least one leg having a leg portion that extends parallel relative to the adjusting axis, according to the invention. This preferred configuration allows the positioning of fastening means for mounting the seat portion to the frame in the leg portion of the frame. This way, material constituting the work chair portions is economically used, according to the invention. Furthermore, positioning of said fastening means in the leg portion of the frame that extends in parallel relative to the adjusting axis aids in adsorbing the forces applied to the frame when an individual is seated, through said leg portion and onto the support surface, according to the invention.

In one embodiment, therefore, the invention relates to an adjustable size work chair according to the invention, the frame comprises at least one leg having a leg portion that extends parallel relative to the adjusting axis.

The adjustable size work chair or the invention needs to be robust, since the chair is suitable for use at school. Therefore, robustness of the adjustable size work chair of the invention is preferably increased by providing the chair with at least one, preferably two or more mounting points for releasably mounting the seat portion to the frame, preferably, one or more leg portions of the frame .

Therefore, in one embodiment the invention relates to an adjustable size work chair according to the invention according to the frame comprises at least one first leg at the front of the chair and at least one second leg at the back of the chair, said said first and second leg are at least in part positioned parallel to the adjusting axis.

Such legs at the front of the adjustable size work chair of the invention and at the back of the chair preferably provide the points for mounting the seat portion at two or more positions in the frame of the work chair, according to the invention. When the seat portion of the work chair of the invention is mounted to multiple legs of the frame, forces applied to the work chair when in use are distributed and absorbed by these multiple legs, according to the invention. This way, the chance for wear and even damage to the chair is diminished, according to the invention.

In particular school chairs need to be resistant to a high degree against toppling, for safe seating, busy and mobile school children. It is therefore preferred that the adjustable size work chair or the invention is prevented from turning over when occupied. Stability of the work chair of the invention is improved when the legs on the front side of the work chair have longitudinal axis that intersects above the seat portion with the longitudinal axis of the legs on the back side of the work chair, according to the invention . The longitudinal axis are both making an angle with the support surface deviating from 90 °, or one of the longitudinal axis is vertically positioned and the second longitudinal axis makes an angle with the support surface deviating from 90 °, according to the invention. This way, the portions of the one or more legs at the front side and the portions of the one or more legs at the back side of the work chair are positioned at the support surface at increased distance from each other, when compared to legs all having vertical longitudinal axes. This increased distance improves the resistance or the adjustable size work chair or the invention against turning over, according to the invention. Furthermore, the leg portions of the frame are preferably tapered from top to bottom.

Thus, in one embodiment the invention relates to an adjustable size work chair according to the invention, the first leg further comprises a portion that extends transversely relative to the adjusting axis.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the frame comprises a first pair of legs and a second pair of legs behind the first pair at the front of the chair, the seat portion is moveably arranged with respect to said two pairs of legs along the adjusting axis, the adjusting axis is at least in part parallel oriented with said first and second pair of legs, preferably, at least in part oriented parallel with said first pair of legs and completely oriented parallel with said second pair of legs.

As said above, it is part of the invention that the seat portion is seat height adjustable and seat depth adjustable by releasing the means for mounting the seat portion to the frame, moving the seat portion in order to adjust seat height and seat depth to a desired new position, and again fastening the seat portion to the frame with supplied fastening means, according to the invention. It is equally preferred according to the invention, when the leg portion or the frame or the adjustable size work chair or the invention comprises a portion that is retractable and / or extendable, preferably telescopically retractable and / or extendable. The seat portion or the adjustable size work chair of the invention is then mounted to the retractable and / or extendable portion of the leg portion of the frame. By retracting or extending said leg portion, seat height and seat depth are concomitantly adjusted, according to the invention. For the purpose according to the invention, the retractable and / or extendable lay portion of the frame is or course retractable and / or extendable in the direction of the adjusting axis along which the seat portion is moveably arranged with respect to the frame.

In one embodiment the invention therefore relates to an adjustable size work chair according to the invention, the frame comprises one or more leg portions, the seat portion is mounted to the leg upper extremity portion relative to the support surface supporting the one or more leg portions, and said said leg upper extremity portion is retractable and / or extendable, preferably telescopically retractable and / or extendable such that the seat portion is moveably arranged with respect to the frame along an adjusting axis and moveable over a seat adjustment range, the adjusting axis makes an angle with the support surface such that moving the seat portion along the direction of said axis in downward direction simultaneously results in moving the seat portion in backward direction, such that the seat height of the chair and the seat depth of the chair are decreased according to a predetermined ratio between the seat height and the seat depth, and vice versa.

The dynamic range of pupil sizes that are conveniently seated at the adjustable size work chair or the invention is preferably further extended by application or a footboard portion supported by the frame, according to the invention. Pupils with relatively small size are equally conveniently seated with their feet on the provided footboard, when compared to relatively large sized pupils who do not require a footboard portion in order to place their feet on a horizontal surface. Now, with the footboard portion, loose hanging legs without feet placed on the support surface is prevented for the pupils having relatively small size.

In one embodiment the invention relates to an adjustable size work chair according to the invention, further including a footboard portion supported by the frame.

Said footboard portion has the shape of a plate, a thread, feet contour, a step, or the like, according to the invention. Thus, the footboard portion of the invention has a variety of sizes and shapes, all equally applicable for their purpose, according to the invention. According to the invention, preferred are footboard portions that do not exceed the front portion or the seat portion or the adjustable size work chair of the invention. Alternatively, and equally applicable are footboard portions that exceed the front portion or the seat portion to some extent, e.g., between 1 to 20 cm, preferably less than 10 cm, according to the invention.

Therefore, in one embodiment the invention relates to an adjustable size work chair according to the invention, the footboard portion is mounted at the frame such that the footboard portion is positioned substantially underneath the front portion or said seat portion relative to a vertical axis when said seat portion is positioned such that seat height and consistent seat depth are minimal.

With the footboard positioned substantially underneath the front portion of the seat portion relative to a vertical axis when said seat portion is positioned such that seat height and concomitant seat depth are minimal, pupils with smallest size can easily place their feet onto the footboard portion when seated. In addition, when the size of the adjustable size work chair is enlarged by increasing seat depth and seat height, the seat portion is moved forwardly such that the front portion of the seat portion is no longer positioned substantially above the footboard portion, according to the invention. In this setting, relatively larger pupils place their feet on the support surface underneath the front portion or the seat portion, according to the invention; the footboard portion is now positioned relatively backwards, behind the feet.

Adjustable size work chairs or the invention are suitable for long term use when adjusted to a certain desired seat height and seat depth. When this certain height and depth is different from the minimal seat height and accompanying minimal seat depth, the footboard portion is (temporarily) superfluous. Therefore, it is part of the invention that the footboard portion is releasably mountable to the frame or the adjustable size work chair, according to the invention.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the footboard portion is releasably mounted to the frame.

An accompanying benefit of the releasably mounted footboard portion according to the invention is that worn and damaged footboard portions are easily (temporarily) released for repair or even for replacement.

It is now due to the inventors that an adjustable size work chair is available, providing its ease of use with regard to size adjustment. That is to say, size adjustment or an adjustable size work chair now only requires adjustment of the seat portion only, according to the invention. However, it is also part of the invention that the backrest portion is height adjustable. The backrest portion of the adjustable size work chair or the invention is positioned such that virtually all pupils with different sizes are seated conveniently, according to the invention. Nevertheless, the invention also provides a height-adjustable backrest portion or the adjustable-size work chair, according to the invention. For convenience, certain pupils, e.g. relatively tall pupils, prefer a backrest portion positioned at increased height relative to the support surface. For ergonomics reason, it is important that the angle between the seat portion and the backrest portion does not deviate too much from the angle of about 95 ° to 105 °, preferably about 97 °, appreciated by pupils as convenient. Therefore, it is part of the invention that when adjusting the height of the backrest portion relative to the support surface, the angle between the backrest portion and the seat portion remains substantially unaltered. Furthermore, for ergonomic reasons, seat depth is not altered when adjusting the height of the backrest portion relative to the support surface, according to the invention.

Thus, in one embodiment the invention relates to an adjustable size work chair according to the invention, the backrest portion is height adjustable vertically relative to the seat portion, such that the angle between said backrest portion and the seat portion remains fixed.

In a further embodiment the invention relates to an adjustable size work chair according to the invention, the backrest portion is height adjustable vertically relative to the seat portion, such that the seat depth remains unaltered upon adjusting the height of said backrest portion.

As said before, tilting the seat portion or the adjustable size work chair or the invention contributing to convenient seating or a pupil. In addition, it is known that it is convenient for the back of seated individuals when the angle between the mainly vertically oriented backrest portion and the mainly horizontally oriented seat portion is larger than 90 °, preferably about 97 °. Therefore, it is part of the invention that the seat portion is slightly tilted, preferably about 3 °, and that the angle between the seat portion and the backrest portion is about 97 °.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the fixed angle between the backrest portion and the seat portion is at least 90 °, preferably between 95 ° and 110 °, more preferably between 96 ° and 105 °, most preferably about 97 °, and the fixed angle between the backrest portion and the support surface is at least 90 °, preferably between 98 ° and 110 °, more preferably between 99 ° and 105 °, most preferably about 100 °.

Seat height, seat depth, relative height of the position of the backrest portion, presence and position of the footboard portion and the angle between the seat portion and the support surface and the angle between the backrest portion and the seat portion of the adjustable size work chair of the invention all contribute to convenient seating of the pupils, according to the invention. In addition, also the size of the seat portion contributes to convenient seating. It is therefore part of the invention that the size of the seats exceeds minimal dimensions or at least 26 cm times 26 cm, preferably about 31.5 cm times 31.5 cm, more preferably about 37.5 cm times 37.5 cm. According to the invention, seats are about 40 cm times about 40 cm. Alternatively, according to the invention, seats are about 45 cm times about 45 cm. Seats of the work chairs of the invention are rectangular in shape, or have a square shape. Rectangular seats of the invention have preferred dimensions of 26 to 45 cm times 25 to 46 cm, preferably 31.5 to 37.5 cm times 31.5 times 37.5 cm. A preferred adjustable size work chair of the invention has a seat portion having dimensions of about 29 to 33 cm for the seat depth times 35 to 40 cm for the seat width, more preferably 31.5 cm for the seat depth times 37.5 cm for the seat width . These seat depths and seat widths or the adjustable size work chairs or the invention facilitate convenient seating or e.g. school pupils and provide enough space.

Thus, in one embodiment the invention therefore relates to an adjustable size work chair according to the invention, the size of the seat portion has dimensions of about 30 to 43 cm times about 30 to 43 cm, preferably about 31.5 cm for the seat depth times about 37.5 cm for the seat width.

An adjustable size work chair of the invention that is adjustable to seat heights and seat depths falling within predetermined ranges indicated in regulatory standards, e.g. the European Standard prEN1729, is preferred according to the invention. Said predetermined ranges are accompanied with a predetermined ratio between certain indicated fixed seat heights and seat depths. It is thus also part of the invention that the adjustable size work chair or the invention is size adjustable to predetermined sizes having a fixed ratio between the seat height and the seat depth. The inventors found that an adjustable size work chair having a size adjusting axis that is directed forwardly relative to the backrest portion and makes an angle of between 55 ° to 75 ° relative to the support surface, preferably between 60 ° and 70 °, more preferably about 66 °, is suitable for setting the size of the work chair to seat heights and accompanying seat depths falling within the range indicated by regulatory standards, and having convenient seat height (:) seat depth ratio.

Thus, in one embodiment the invention relates to an adjustable size work chair according to the invention, according to the adjusting axis is directed forwardly relative to the backrest portion and makes an angle of between 55 ° to 75 ° relative to the support surface, preferably between 60 ° and 70 °, more preferably about 66 °.

Convenient and muscle strain free seating is facilitated by the seat height and seat depth of a work chair having a predetermined ratio. Particularly convenient is an adjustable size work chair with a seat height (:) seat depth ratio for each combination of seat height and depth, falling in the range between 1.17 and 1.32 when moving the seat portion along the direction of the adjusting axis, preferably between 1.20 and 1.30, more preferably between 1.20 and 1.28, most preferably at about 1.25, according to the invention. Alternatively, and equally preferred is an adjustable size work chair with a seat height (:) seat depth ratio for each combination of seat height and depth, falling in the range between 1.03 and 1.16 when moving the seat portion along the direction of the adjusting axis , preferably between 1.04 and 1.14, more preferably between 1.05 and 1.11, most preferably at about 1.08, according to the invention.

In one embodiment the invention relates to an adjustable size work chair according to the invention, according to the ratio between vertical seat height adjustment of the seat portion and concomitant horizontal seat depth adjustment of the seat portion is between 1.17 and 1.32 when moving the seat portion along the direction of the adjusting axis, preferably between 1.20 and 1.30, more preferably between 1.20 and 1.28, most preferably at about 1.25.

According to the invention, in order to conveniently seat pupils or different size according to regulatory standards, an adjustable size work chair has a seat that is height adjustable between 20 cm and 55 cm, preferably between 26 cm and 51 cm, more preferably between 31 cm and 48 cm, most preferably between 38 cm and 46 cm. In addition, according to the invention, in order to conveniently seat pupils or different size according to regulatory standards, an adjustable size work chair has a seat that is depth adjustable between 25 cm and 48.5 cm, preferably between 28 cm and 48, 5 cm, more preferably between 31.5 cm and 36 cm. Of course, as long as combinations of seat height and seat depth allow convenient and muscle strain free seating or pupils, also an adjustable size work chair having seat heights narrower than 20 cm and accompanying seat depths narrower than 25 cm is part of the invention, for seating relatively short and small pupils. Equally preferred is an adjustable size work chair having seat heights larger than 55 cm and accompanying seat depths larger than 48.5 cm, according to the invention, for conveniently seating relatively tall pupils. Of course, also part of the invention is an adjustable size work chair having any combination of predetermined seat sizes selected from these ranges of seat heights and accompanying seat depths.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the seat height relative to the support surface is between 20 cm and 55 cm, preferably between 26 cm and 51 cm, more preferably between 31 cm and 48 cm , most preferably between 38 cm and 46 cm, and the seat depth is between 25 cm and 48.5 cm, preferably between 28 cm and 48.5 cm, more preferably between 31.5 cm and 36 cm.

For most applications, e.g. for use at school, an adjustable size work chair which is adjustable to a relatively small number of predetermined and fixed combinations or seat height and accompanying seat depth, is suitable. For use at school, for example, an adjustable size work chair having the position of the seat portion adjustable in a stepwise manner at predetermined and fixed seat heights or at least at about 31 cm, 38 cm, 43 cm and 46 cm and concomitantly and fixed seat depths or at least at least 28 cm, 31.5 cm, 34 cm, 36 cm, or a selection of said fixed seat heights and consistent fixed seat depths, is suitable according to the invention.

In one embodiment the invention relates to an adjustable size work chair according to the invention, the position of the seat portion is adjustable in a stepwise manner at predetermined and fixed seat heights or at least at about 31 cm, 38 cm, 43 cm and 46 cm and concomitantly fixed seat depths or at least at least 28 cm, 31.5 cm, 34 cm, 36 cm, or a selection of said fixed seat heights and concomitant fixed seat depths.

Also part of the invention is an adjustable size work chair having more or different predetermined and fixed seat heights and accompanying seat depths, preferably adjustable in a stepwise manner, according to the invention.

For most applications, such as at school or in the office, a work chair is used in combination with a work table.

In view of this, a second aspect of the present invention related to an assembly including at least one adjustable size work chair according to the invention, preferably 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 or said chairs, and at least one adjustable size work table, preferably two tables, said table including a horizontal leaf portion relative to the support surface and a table frame supporting the horizontal leaf portion relative to said support surface support the work table, be the height or said work table leaf portion relative to the support surface is adjustable at predetermined positions.

It is also part of the invention that the assembly of the invention comprises an adjustable size work chair according to the invention in combination with a work table having a predetermined and fixed size. Whether course, the adjustable size work chair or the invention is applicable with a series or work tables having varying sizes. Most preferably, though, the assembly of the invention includes an adjustable size work chair and an adjustable size work table, the work table is adjustable at heights adapted to the predetermined seat heights of the work chair, according to the invention. Work table heights that are combined conveniently with predetermined heights of the adjustable size work chair of the invention, are for example heights between 40 cm and 100 cm, preferably between 46 cm and 82 cm, more preferably between 50 cm and 80 cm, most preferably between 53 cm and 76 cm, according to the invention.

Therefore, in an embodiment, the invention provides an assembly according to the invention, according to the height of the work table leaf portion relative to the support surface is adjustable between 40 cm and 100 cm, preferably between 46 cm and 82 cm, more preferably between 50 cm and 80 cm, most preferably between 53 cm and 76 cm.

Preferred assemblies of the invention suitable for relatively small sized individuals (eg smaller than 93 cm) and / or relatively large sized individuals eg taller than 207 cm), include work chairs and work tables having heights of the work table leaf that are smaller than 40 cm or larger than 100 cm, according to the invention.

However, in a preferred embodiment of the invention, for an adjustable size work table of the assembly of the invention, the height of the work table leaf relative to the support surface is adjustable in a stepwise manner at predetermined and fixed heights or at least at about 53 cm, 59 cm, 64 cm, 71 cm and 76 cm, or a selection.

Thus, in one embodiment the invention relates to an assembly according to the invention, according to the height of the work table leaf relative to the support surface is adjustable in a stepwise manner at predetermined and fixed heights or at least at about 53 cm, 59 cm, 64 cm, 71 cm and 76 cm, or a selection thereof.

The adjustable size work chair or the invention is combined with work tables having a widely varying range or table leaf sizes. For example, at school pupils are seated individually at a work chair and a work table of the invention, with the work table having a table leaf about 100 cm times about 50 cm, or about 80 cm times about 45 cm. Alternatively, pupils are seated group wise, with 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 pupils seated in a single group, at one or more work tables positioned side by side. For example, pupils are seated group wise with 2, 3, 4, 6, 8, 9, 10, 12 pupils seated in a single group, at a single work table or at two work tables. Therefore, it is part of the invention that the work table of the assembly according to the invention has a work table leaf portion having dimensions of about 100 to 240 cm times about 50 to 120 cm, preferably about 160 cm times about 80 cm, according to the invention. For, among others, reasons of strength and weight, the table leaf has a third dimension of between about 0.9 cm to 5 cm, preferably between about 1.2 cm to 3 cm, more preferably between about 1.5 cm to 2.2 cm, most preferably about 1.8 cm, according to the invention. Within this range for the table leaf portion thickness according to the invention, the work table of the assembly of the invention has sufficient strength for its purpose, and the weight of the work table remains below certain limits convenient for lifting or repositioning the work table by human force.

In one embodiment the invention thus related to an assembly according to the invention, according to the size of the work table leaf has dimensions of about 100 to 240 cm times about 50 to 120 cm, preferably about 160 cm times about 80 cm, third dimension of the work table leaf portion is between about 0.9 cm to 5 cm, preferably between about 1.2 cm to 3 cm, more preferably between about 1.5 cm to 2.2 cm, most preferably about 1.8 cm.

It is preferred that the work table leaf portion or the work table or the assembly of the invention has a square or rectangular shape. Equally preferred is work table leaf having a different shape. It is an important contribution to the art that a preferred work table comprised by the assembly of the invention, has leg portions positioned underneath the work table leaf portion such that the leg portions minimally interfere with feet of seated individuals positioned under the work table, according to the invention. In order to arrive at this convenient seating at the work table, with reduced disturbance by leg portions of the work table positioned at the support surface, according to the invention, said leg portions are positioned at the supporting surface at relatively large distance from the sides and comers of the table leaf portion. Convenient and preferred according to the invention, is an assembly, according to the table frame comprises one or more leg portions mounted to the work table leaf portion such that the one or more leg portions are supported by the support surface at positions underneath the central portion of the leaf portion located at least about 10 cm to 20 cm, preferably at least about 15 cm away from the edge portions the work table leaf portion and least about 14 cm to 29 cm, preferably at least about 21 cm away from the comer portions of the work table leaf portion, relative to the periphery or the leaf portion.

In a preferred embodiment of the present invention, therefore, an assembly is provided according to the invention, the table frame comprises one or more leg portions mounted to the work table leaf portion such that the one or more leg portions are supported by the support surface at positions underneath the central portion of the leaf portion located at least about 10 cm to 20 cm, preferably at least about 15 cm away from the edge portions the work table leaf portion and least about 14 cm to 29 cm, preferably at least about 21 cm away from the comer portions of the work table leaf portion, relative to the periphery or the leaf portion.

For improved convenience of seating, with sufficient amount of space on the support surface underneath a work table of an assembly of the invention, for placing the feet of a seated individual, the table frame of the assembly of the invention comprises at least one leg portion including a recess facing the support surface, said recess providing space for at least two human feet positioned underneath the table leaf.

Herewith, in one embodiment the invention relates to an assembly according to the invention, the table frame comprises at least one leg part comprising a recess facing the support surface, said recess providing space for at least two human feet positioned underneath the table leaf and next to said put portion in contact with the support surface.

In one embodiment the invention relates to an adjustable size work chair according to the invention or an assembly according to the invention, according to the lower leg extremity of the legs of the chair and / or the table in contact with the support surface is provided with releasable means for slide support, said said means for slide support are adaptable to the surface material or the support surface.

Typically, work chairs, and even work tables, are frequently moved around in, for example, the classroom or office space. In addition, chairs and tables are used time by time in different classrooms or office spaces, perhaps having support surfaces with different materials. Therefore, it is part of the invention that the work chair and the work table of the assembly of the invention are provided with releasable means for slide support. The releasable means for slide support are not only adaptable to the material of the support surface, but are also easily replaced, for example when worn or damaged, as part of the invention.

In a preferred embodiment the invention relates to an adjustable size work chair according to the invention and / or an assembly according to the invention, according to the predetermined and fixed seat heights and seat depths and the predetermined and fixed table leaf heights are coded, preferably color coded or coded with height marks, preferably for each separate fixed height and depth, preferably preferably the seat heights of about 31 cm, 35 cm, 38 cm, 43 cm and 46 cm have the same code as the table leaf heights of about 53 cm , 59 cm, 64 cm, 71 cm and 76 cm, respectively.

For reasons of convenience, coded marks at the adjustable size work chair and at the adjustable size work table are such that it is easily retrieved which seat height / seat depth relates to which work table size, according to the invention. At least the combinations of seat size and work table size according to a regulatory standard are coded, e.g. color coded, according to the invention. For example, according to the invention, for an assembly said combinations are coded, the work chair is stepwise size adjustable at predetermined and fixed seat heights of 38 cm, 43 cm and 46 cm with concomitant seat depths of respectively 31.5 cm, 34 cm and 36 cm, and the work table is stepwise size adjustable at predetermined and fixed table leaf heights of 64 cm, 71 cm and 76 cm.

Therefore, in one embodiment the invention relates to an assembly according to the invention, the work chair is stepwise size adjustable at predetermined and fixed seat heights of 38 cm, 43 cm and 46 cm with concomitant seat depths of respectively 31.5 cm, 34 cm and 36 cm, and the work table is stepwise size adjustable at predetermined and fixed table leaf heights of 64 cm, 71 cm and 76 cm.

In one embodiment the invention relates to an adjustable size work chair according to the invention and the adjustable size work table according to the invention, the portions that represent the chair and the portions that constitute the table are releasably mounted such that the unmounted portions of the chair and the table when stacked take a smaller outer volume than the volume of the mounted chair and the mounted table together.

Most often, storage space at school or at the office is limited. For example, at school, spare assemblies according to the invention, and at least spare work chairs according to the invention, are stock piled, consuming limited storage space. It is therefore a preferred contribution to the art that is the assembly of the invention, or releasably mounted portions, as part of the invention. Furthermore, the assembly of the invention preferably contained or mounted portions that are flat, according to the invention. Herewith, as part of the invention, released portions of the work chair and the work table of the invention are stock piled, consuming minimal volume or storage space, when compared to the volume occupied by assembled assemblies.

Another benefit of the flat portions constituting the assembly of the invention being releasable, that any portion is releasable and replaceable, independent from other portions of the assembly, according to the invention. This way, worn or damaged portions of the assembly are easily replaced, without the need for a complete work chair or work table having a single portion damaged.

Commonly, a human is able to lift and reposition a work table with a weight of about 50 kg. Therefore, it is part of the invention that the work table of the assembly of the invention maximally weighs about 100 kg, preferably 50 kg or less. This way, the work table is liftable and replaceable by e.g. 2 or even 1 individual, according to the invention.

In one embodiment the invention relates to an assembly according to the invention, according to the work table weighs 100 kg or less, preferably 75 kg or less, more preferably about 50 kg, most preferably less than 50 kg.

According to the invention, any material having required strength and specific gravity for use in a chair and / or in a table, is equally suitable for use in the assembly according to the invention. For seats and work table leafs, specific attention is drawn to convenient heat transfer between the parts of the seated individual's body and the seat portion or the table leaf portion. It is state of the art that has particular wood and plastic characteristics that satisfy these aforementioned requirements. Therefore, the assembly of the invention is preferably constituted of materials such as wood and plastic, or combinations thereof. Whether course, parts of the work chair of the invention or of the assembly of the invention made in part of other materials, such as any metal or glass fiber, are equally preferred according to the invention. However, it is preferred according to the invention to assemble the work chair or assembly of the invention with most portions, preferably all portions made of a single material.

In one embodiment the invention relates to an adjustable size work chair according to the invention and the adjustable size work table according to the invention, the chair and / or the table are made of material selected from wood, plastic, or combinations thereof, preferably wood.

In one embodiment the invention relates to an adjustable size work chair and the adjustable size work table according to the invention, the chair and / or the table are made of plate material, preferably wooden plate material, preferably the chair and the table are made of wooden plate material.

Surprisingly, the inventors found that the assembly of the invention comprising four adjustable size work chairs according to the invention, consists of portions having outer dimensions with all portions fitting two wooden plates, preferably having standard dimensions, preferably a single wooden plate, preferably having standard dimensions. Therefore, an assembly of the invention is retrievable from e.g. two or such wooden plates having standard dimensions, i.e. a size of about 122 cm times about 244 cm, according to the invention. This allows for economic application of the plate material, e.g. wooden plates, with minimal loss or (parts of) plate material not fitting any portion constituting the assembly of the invention.

In one embodiment the invention thus related to an adjustable size work chair according to the invention and an adjustable size work table according to the invention, the outer dimensions of the portions constituting the chair and the portions constituting the table are such that all portions constituting four chairs and one table are retrievable from two pieces of material, preferably from a single piece of material, preferably from the material is wood, preferably from a wooden plate with dimensions of at least about 29,000 cm2, preferably at least about 65,000 cm2, preferably at least about 120 cm to 160 cm times 275 cm to 320 cm, more preferably at least about 240 cm to 320 cm times 275 cm to 320 cm, preferably about 122 cm times about 244 cm, according to the third dimension of the plates is between about 0.9 cm to 5 cm, preferably between about 1.2 cm to 3 cm, more preferably between about 1.5 cm to 2.2 cm, most preferably about 1.8 cm.

The inventors found in particular an assembly of the invention is suitably made of wood, ie from two wooden plates, according to the invention, according to the assembly comprises at least one work chair of the invention, preferably two, three or four work chairs, most preferably four work chairs. Wood is a material particularly suitable for retrieving the portions constituting the work chair and the work table of the invention, which are assembled in a releasable manner, according to the invention. For example and preferably, wooden portions constituting the work chair and the work table of the invention are assembled applying Allen bolts. Equally preferred is any other releasable way of mounting wooden portions together, according to the invention. A third aspect of the present invention relates to a method for assembling an assembly including four size adjustable work chairs according to the invention and including one size adjustable work table according to the invention, including the steps of: a) providing two wooden plates with outer dimensions of at least about 122 cm times 244 cm; b) retrieving the portions constituting four chairs and one table from said plates, preferably by sawing; and assembling the chair portions and assembling the table portions such that the four chairs and one table are build and such that the chairs and the table are releasable back into their constituting respective portions.

In one embodiment the invention relates to a method according to the invention, the two plates or wood have standardized dimensions. A fourth aspect of the present invention relates to the use of a size adjustable work chair according to the invention or obtainable by the method of the invention and / or use of an assembly including at least one size adjustable work chair according to the invention or available by the method of the invention and at least one size adjustable work table according to the invention or available by the method of the invention, in education such as education in a classroom, preferably in education for children, preferably at school, or use of said chair and / or said assembly in the office.

The present invention will be illustrated further by means of the following preferred though non-limiting Examples of the invention, with reference to the drawings. It should be understood that a person skilled in the art is able to provide modified and / or equivalent adjustable size work chairs and assemblies including such chairs and an adjustable size work table, without departing from the scope of the invention.

EXAMPLES

Referring to the figures, Figure 1, 2 and 6 show an adjustable size work chair (15, 150, 501) according to the invention. The adjustable size work chair according to the invention comprises a backrest portion (11, 110), a seat portion (10, 100) and a frame (12, 120) supporting the backrest portion and the seat portion relative to a support surface (14 , 140) supporting the work chair. In the figures, the backrest portion and said seat portion of the work chair is positioned at a fixed angle relative to each other, according to the invention. The seat portion in Figure 1 and 2 is moveably arranged with the frame along an adjusting axis (a, a ') and moveable over a seat adjustment range, with the adjusting axis makes an angle with the support surface such that moving the seat portion along the direction of said axis in downward direction simultaneously results in moving the seat portion in backward direction, such that the seat height of the chair and the seat depth of the chair are decreased according to a predetermined ratio between the seat height and the seat depth, and vice versa. In the exemplary work chair of the invention, in Figure 1 the adjusting axis is a linear axis. Herewith, the seat height and the seat depth are adjustable at a fixed ratio relative to each other.

In Figure 1A and B and in Figure 2, the seat portion of the exemplified work chair or the invention is stepwise moveable. For example, the seat portion is moveable between positions defined by the means for fastening the seat portion to the frame or the adjustable size work chair of the invention, ie by the means for fastening at positions (16, 16 ', 16 ”) in Figure 1A or positions (160, 160 ', 160 ”) in Figure IB. In Figure 2, for example, three steps for the position of the adjustable seat portion are indicated (200, 201, 202). For example, the seat portion is fastened at the frame at position (16) in seat portion position (200) and at position (16 ") in seat portion position (200"), according to the invention. The seat portion is then moved from seat portion position (200) to (200 ") along the direction or adjusting axis (a").

Figure 2 depicts an exemplary adjustable size work chair of the invention, the seat portion makes an angle of 3 °, with the front of the seat portion (200 ') being the high end of the seat portion and the back of the seat portion (200 ”) being the low end or the seat portion.

In Figure IB, an adjustable size work chair of the invention is shown, having a frame including at least one leg (12 ") having a leg portion (12") that extends parallel relative to the adjusting axis. In Figure IB, also the second leg at the front of the chair comprises a leg portion extending parallel relative to the adjusting axis (a).

In Figure 1A and IB the frame of the exemplified work chair according to the invention comprises at least one first leg (12 ', 120') at the front of the chair and at least one second leg (19, 121) at the back of the chair, said said first leg and second leg have a leg portion (12 ”, 19 ', 190, 12Γ) that extends parallel relative to the adjusting axis. Furthermore, in the exemplary work chair according to the invention depicted in Figure IB, the first leg (120 ") further comprises a portion (122) that extends transversely relative to the adjusting axis (a").

The adjustable size work chair according to the invention and depicted in Figure IB also shows the frame including a base portion including a first pair of legs (1,2) and a second pair of legs (3, 4) behind the first pair at the front of the chair, in which the seat portion (100) is moveably arranged with said two pairs of legs along the adjusting axis (a '), the adjusting axis is at least in part parallel oriented with said first pair of legs and second pair of legs, preferably, at least in part oriented parallel with said first pair of legs and completely oriented parallel with said second pair of legs.

Figure 1A shows the work chair of the invention with a footboard portion (13) supported by the frame. Here, the footboard portion is made of wooden plate material, i.e. the same wooden plate material as all other portions constituting the work chair of the invention. In Figure 1A, the adjustable size work chair is shown with its seat portion at the lowest height (smallest seat depth). It is seen that now the front portion (10 ') or the seat portion (10) is positioned substantially above the footboard portion, allowing easy access for the feet or a seated individual. Furthermore, the footboard portion is mounted releasable in the exemplified work chair of the invention, indicated by the position (18) or the Allen bolt.

The adjustable size work chair of the invention, as depicted in Figure 1 and 2, is here equipped with a height adjustable backrest portion (11, 110, 210). Comparing the work chair drawn in Figure 1A and IB, it is seen that the height of the backrest is adjusted by releasing Allen bolt (17, 170), turning the backrest 180 °, and again fastening the backrest with the Allen bolt. This way, this adjustable size work chair or the invention is provided with a backrest that is positioned at two different heights. Adjustment of the height of the backrest does not change the angle between the backrest portion and the seat portion, nor changes the seat depth of the work chair. In this example of an adjustable size work chair according to the invention, the angle β between the backrest portion and the seat portion is fixed and is 97 °. In this example of an adjustable size work chair according to the invention, the angle γ between the backrest portion and the support surface is fixed and is 100 °.

The exemplified adjustable size work chairs in Figure 1, 2 and 6 have a seat portion having dimensions of 31.5 cm for the seat depth times 37.5 cm for the seat width. The seat portions are made from wooden plate material, as are all other portions together constituting the work chair of the invention.

For the exemplary work chairs according to the invention, in the drawings, the angle between the adjusting axis (a, a ’, a”) is 66 °.

Figure 1A shows an adjustable size work chair of the invention, the ratio between vertical seat height adjustment of the seat portion and concomitant horizontal seat depth adjustment of the seat portion is 1.21, 1, 26 and 1.28, with the seat portion fastened at position (16, 16 ', 16 ”), respectively. The seat height relative to the support surface is 38 cm for the seat portion depicted in Figure 1 A. The seat height relative to the support surface is 46 cm for the seat portion depicted in Figure IB. For the work chairs according to the invention and depicted in Figure 1 and 2, seat height and accompanied seat depth is adjustable in a stepwise manner. Steps are defined by the fastening means for the seat portion in the frame, i.e. the Allen bolts positioned at e.g. position 160, 160 and 160, respectively, in Figure IB.

In Figure 6, examples of assemblies according to the invention, including an adjustable size work chair or an adjustable size work table or an invention, are shown (590, 591, 592). Shown are assemblies of two work tables (500, 500 ') arranged as a square, surrounded by twelve work chairs (501-512), and two assemblies of a work table (500) surrounded by eight (Figure 6B) and six (Figure 6B) 6C) work chairs. In Figure 6, it is depicted that the work table is frame including the leg portions of the work table, is positioned such that the leg portions are positioned at a distance of 15 cm from the sides of the table and a distance of 21 cm from the edges or the table leaf.

Figure 3 and 4 depict the constituents of an exemplary adjustable size work table (350, 450) or the invention. Shown are a horizontal leaf portion (300, 400), mountable to a frame portion including leg portions (310, 310 ", 310", 328, 327, 360, 360 ", 410", 411, 411 ", 460).

In the exemplified adjustable size work table of the assembly of the invention, the height of the table leaf is adjustable at predetermined and fixed values in a stepwise manner. Releasing the size adjustable portion (300, 310, 360, 360 "; Figure 3) or the work table, and fastening said portion again after height adjustment is by releasing and fastening or Allen bolts, according to the invention. All bolts are positioned as depicted by example positions 324, 325, 326, according to the invention. Predetermined heights of the work table of the invention are set by fastening the Allen bolts at a position selected from 320, 320 "or 320", and 321, 321 "or 321", and 322, 322 "or 322" for the Allen bolts at position 324, 325 and 326, respectively. For the adjustable size work table or the exemplified assembly of the invention, predetermined work table leaf heights are at 64 cm, 71 cm and 76 cm, respectively. Said heights are visualized in Figure 4, as indicated by the positions of the table leaf (400, 401, 402) for work table 450 or the exemplified assembly of the invention.

The adjustable size work table of the exemplified assembly of the invention has a leg portion (311, 31Γ, 411, 41Γ) including a recess (330, 430) facing the support surface, said recess providing space for placing two and three feet of seated individuals.

The adjustable size work table or the exemplified assembly of the invention has legs bearing a lower leg extremity in contact with the support surface, that is provided with releasable means for slide support (482) adapted to the surface material or the support surface.

Figure 5A and 5B show two wooden plates with the contours of all constituents of an assembly according to the invention, said exemplified assembly of the invention consisting of four adjustable size work chairs or the invention and one adjustable size work table, according to the invention. Dimensions (701, 70Γ) and (700, 700 ") or the wooden plates (702, 702") are about 122 cm times about 244 cm, in this exemplified embodiment of the invention.

Claims (37)

A size-adjustable work chair (15, 150) comprising a back support section (11), a seat section (10) and a frame (12) which supports the back support section and the seat section on a support surface (14) supporting the work chair, the the relevant back support part and the relevant seat part are placed at a fixed angle relative to each other, in which the seat part is movably positioned along an adjusting axis (a) in relation to the frame and is movable over an adjusting region of the seat, wherein the adjusting axis is an angle with the support surface so that moving the seat portion in the downward direction of the respective axis results in the backward movement of the seat portion such that the seat height of the chair and the seat depth of the chair are reduced according to a predetermined set ratio between the seat height and the seat depth, and vice versa. A size-adjustable work chair according to claim 1, wherein the adjusting axis is a linear axis and wherein the seat height and the seat depth are adjustable according to a fixed ratio relative to each other. A size-adjustable work chair according to claim 1 or 2, wherein the seat portion is movable stepwise (16, 16 ", 16"). A size-adjustable work chair according to any one of claims 1-3, wherein the seat portion makes an angle of between 1 ° and 6 ° with the support surface, preferably about 3 °, the front (10 ', 200') of the seat portion is the high end of the seat portion and the rear of the seat portion (200 ") is the low end of the seat portion. A size-adjustable work chair according to any one of claims 1-4, wherein the frame comprises at least one leg (12 ") with a leg portion (12") extending parallel relative to the adjustment axis. A size-adjustable work chair according to any of claims 1-5, wherein the frame comprises at least one first leg (12 ', 120') on the front of the chair and at least one second leg (19, 121) on the rear of the chair, wherein said first leg and second leg have a leg portion (12 ", 19 ', 190, 121") that extends parallel relative to the adjusting axis. A size-adjustable work chair according to claim 6, wherein the first leg (120 ") further comprises a portion (122) that extends transversely relative to the adjusting axis (a"). A size-adjustable work chair according to any one of claims 1-7, wherein the frame comprises a first pair of legs (1,2) and a second pair of legs (3, 4) behind the first pair of legs on the front of the chair , wherein the seat portion (100) is movably mounted along the adjusting shaft (a ') in relation to respective two pairs of legs, wherein the adjusting shaft is at least partially parallel with the respective first pair of legs and second pair of legs, preferably at least partially parallel. with corresponding first pair of legs and runs completely parallel with relevant second pair of legs. A size-adjustable work chair according to any of claims 1-8, wherein the frame comprises one or more leg portions, wherein the seat portion is attached to the upper end portion of the leg relative to the support surface which the one or more leg portions and in which the relevant upper end part of the leg can be shortened and / or extended, preferably telescopically shortened and / or extendable so that the seat portion is movable over the seat adjustment area. A size-adjustable work chair according to any of claims 1-9, further comprising a footrest portion (13) supported by the frame (12). A size-adjustable work chair according to claim 10, wherein the footrest portion is attached to the frame so that the footrest portion is positioned substantially below the front portion of the respective seat portion relative to a vertical axis when the respective seat portion is positioned such that the seat height and the associated session depth are minimal. A size-adjustable work chair according to claim 10 or 11, wherein the footrest portion is releasably attached (18) to the frame. A size-adjustable work chair according to any of claims 1 to 12, wherein the back support portion (11, 110) is height-adjustable (17, 170) in the vertical direction relative to the seat portion (10, 100), so that the The angle between the backrest section and the seat section remains unchanged. A size-adjustable work chair according to claim 13, wherein the back support portion is vertically adjustable in height relative to the seat portion, such that the seat depth remains unchanged when the height of the back support portion is adjusted. A size-adjustable work chair according to any one of claims 1-14, wherein the fixed angle between the backrest portion and the seat portion is at least 90 °, preferably between 95 ° and 110 °, more preferably between 96 ° and 105 ° , most preferably about 97 °, and wherein the fixed angle between the back support portion and the support surface is at least 90 °, preferably between 98 ° and 110 °, more preferably between 99 ° and 105 °, most preferably about 100 ° . A size-adjustable work chair according to any of claims 1-15, wherein the size of the seat portion (10, 100) has dimensions of about 30 to 43 cm by about 30 to 43 cm, preferably about 31.5 cm for the depth of the seat at approximately 37.5 cm for the width of the seat. A size-adjustable work chair according to any one of claims 1-16, wherein the adjusting shaft (a, a ', a') is directed forward relative to the back support portion (11, 110, 210) and an angle of between 55 ° to 75 ° relative to the support surface (14, 140, 240), preferably between 60 ° and 70 °, more preferably about 66 °. A size-adjustable work chair according to any of claims 1-17, wherein the ratio between the adjustment of the seat height in the vertical direction and the simultaneous adjustment of the seat depth in the horizontal direction is between 1.17 and 1.32 when the seat portion is moved along the direction of the adjusting shaft, preferably between 1.20 and 1.30, more preferably between 1.20 and 1.28, most preferably about 1.25. A size-adjustable work chair according to any one of claims 1-18, wherein the seat height relative to the support surface is between 20 cm and 55 cm, preferably between 26 cm and 51 cm, more preferably between 31 cm and 48 cm, most preferably between 38 cm and 46 cm, and wherein the seat depth is between 25 cm and 48.5 cm, preferably between 28 cm and 48.5 cm, more preferably between 31.5 cm and 36 cm. A size-adjustable work chair according to any of claims 1-19, wherein the position of the seat portion is stepwise adjustable at preset and fixed seat heights (16, 16 ', 16 ", 160,160", 160 ") of at least about 31 cm, 38 cm, 43 cm and 46 cm and simultaneously and respectively on preset and fixed seat depths (16, 16 ', 16 ", 160, 160', 160") of at least about 28 cm, 31.5 cm, 34 cm, 36 cm, or a selection of relevant fixed seat heights and simultaneous fixed seat depths. An assembly (590, 591, 592) comprising at least one size-adjustable work chair (15, 150, 250) according to any of claims 1-20, preferably 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 chairs, and at least one size-adjustable work table (350,450, 500), preferably two tables (500, 500 '), concerning a table comprising a horizontal tabletop portion (300, 400) relative to the support surface ( 340, 440) and a table frame (370,470, 570, 570 ') which supports the horizontal tabletop portion relative to the support surface supporting the work table, wherein the height of the relevant tabletop portion of the work table is adjustable to determined positions relative to the supporting surface. An assembly according to claim 21, wherein the height of the tabletop portion of the work table is adjustable between 40 cm and 100 cm relative to the support surface, preferably between 46 cm and 82 cm, more preferably between 50 cm and 80 cm, most preferably between 64 cm and 76 cm. An assembly according to claim 21 or 22, wherein the height of the tabletop portion of the work table is stepwise adjustable relative to the support surface to preset and fixed heights of at least about 53 cm, 59 cm, 64 cm, 71 cm and 76 cm, or a selection of these. An assembly according to any of claims 21-23, wherein the size of the tabletop portion of the work table has dimensions of about 100 to 240 cm at about 50 to 120 cm, preferably about 160 cm at about 80 cm, wherein the third dimension of the tabletop portion of the work table is between about 0.9 cm to 5 cm, preferably between about 1.2 cm and 3 cm, more preferably between about 1.5 cm to 2.2 cm, most preferably about 1, 8 cm. The assembly of any one of claims 21-24, wherein the table frame comprises one or more leg portions (310, 310 ', 310 ", 360, 360", 410 ", 411, 41Γ, 460) attached to the tabletop portion of the work table such that the one or more leg portions are supported by the support surface (340) at positions below the central portion of the tabletop portion at the position of at least about 10 cm to 20 cm, preferably at least about 15 cm away from the edge portion of the tabletop portion from the work table and at least about 14 cm to 29 cm, preferably at least about 21 cm away from the corner portions of the tabletop portion of the work table relative to the peripheral portion of the tabletop portion. An assembly as claimed in any one of claims 21-25, wherein the table frame comprises at least one leg portion (310 ") comprising a recess (330) facing the support surface, offering the relevant recess space for at least two human feet positioned below the table top. The size-adjustable work chair according to any of claims 1-20 or the assembly according to any of claims 21-26, wherein the lower end of the chair legs and / or the table legs (480, 481) which are in contact with the support surface is provided with removable means for supporting sliders (482), wherein relevant means for supporting slides can be adapted to the surface material of the support surface. The size-adjustable work chair according to claim 19 or 20 and / or the assembly according to one of claims 21 to 27, wherein the preset and fixed seat heights and seat depths and the preset and fixed table top heights are coded, preferably with a color coding or coded with height markings, preferably for each fixed height and depth separately, wherein preferably the seat heights of about 31 cm, 35 cm, 38 cm, 43 cm and 46 cm have the same code as the heights of the table top of about 53 cm respectively , 59 cm, 64 cm, 71 cm and 76 cm. An assembly according to any one of claims 21 to 28, wherein the size of the work chair is stepwise adjustable to predetermined and fixed seat heights of 38 cm, 43 cm and 46 cm with simultaneous seat depths of 31.5 cm, 34 cm and 36 respectively cm, and in which the worktable can be gradually adjusted in size to preset and fixed tabletop heights of 64 cm, 71 cm and 76 cm. The size-adjustable work chair according to any of claims 1-29 and the size-adjustable work table according to any of claims 21-29, wherein the portions comprising the chair and the portions comprising the table (700, 700 ') are detachable so that detached portions of the chair and table occupy a smaller outer volume than the volume of the assembled chair and the assembled table together. An assembly according to any of claims 21-30, wherein the work table weighs 100 kg or less, preferably 75 kg or less, more preferably about 50 kg, most preferably less than 50 kg. The size-adjustable work chair according to any of claims 1-31 and the size-adjustable work table according to any of claims 21-31, wherein the chair and / or the table are made of material selected from wood, plastic, or thereof a combination, preferably wood. The size-adjustable work chair and the size-adjustable work table according to claim 32, wherein the chair and / or the table are made of sheet material (702, 702 '), preferably wooden sheet material, preferably the chair and the table are made of of wooden plate material. The size-adjustable work chair according to any of claims 1-33 and the size-adjustable work table according to any of claims 21-33, wherein the outer dimensions of the sections that construct the chair and the sections that support the table (700, 700 ') are such that all parts that build up four tables and one table can be obtained from two pieces of a material, preferably from a single piece of a material, in which the material is preferably wood, preferably a wooden plate ( 702, 702 ') with dimensions of at least 29,000 cm 2, preferably from at least 65,000 cm 2, preferably at least about 120 cm to 160 cm by 275 cm to 320 cm, more preferably from at least about 240 cm to 320 cm at 275 cm to 320 cm, preferably about 122 cm to about 244 cm, wherein the third dimension of the plates is between about 0.9 cm to 5 cm, preferably between about 1.2 cm to 3 cm, more preferably between approximately 1.5 cm to 2 1.2 cm, most preferably about 1.8 cm. A method for assembling an assembly comprising four size-adjustable work chairs according to any of claims 1-34 and comprising one size-adjustable work table according to any of claims 21-34, comprising the steps of: a) providing two wooden plates with outer dimensions of at least about 122 cm by 244 cm; b) obtaining the parts that the four chairs and the single table build up from the relevant plates, preferably by sawing; and c) assembling the chair sections and assembling the table sections so that the four chairs and the single table are made and such that the chairs and the table are detachable back into their respective sections from which they are constructed. The method of claim 35, wherein the two wooden plates have standardized dimensions. Use of a size-adjustable work chair according to one of claims 1-34 or available according to the method of claim 35 or 36 and / or use of an assembly comprising at least one size-adjustable work chair according to one of claims 1-34 or available according to the method of claim 35 or 36 and at least one size-adjustable work table according to any of claims 21-34 or available with the method of claim 35 or 36, in education such as teaching in a classroom, preferably in education for children, preferably at school, or use of the relevant chair and / or assembly in an office environment.