EXTENDABLE TABLE

Technical Field

The invention relates to a main top comprising a first surface and an opposite second surface, said main top being mounted to a first rail, a leaf, said leaf being arranged in a first position below the second top and said leaf comprising connection means for connecting to a second rail, said second rail being axially slidable relative to the first rail, said leaf further comprising folding means, and by activation of said folding means, the surface area of the leaf changes from a first surface area to a second surface area different from the first surface area, said extension table also comprising a support frame, said support frame fixedly connected to a third rail parallelly arranged relative to the first and second rail. Background

Extension tables mainly function based on two principles. According to the first principle, the main top comprises two fixed tops mounted on slidable rails. Said rails can be pulled apart, and the leaf or leaves are placed in the area between the two separated tops. DE 3636169 discloses an extension table functioning based on this principle.

According to the second principle, the leaf is placed at one short side of the main top and is either pulled out from an area underneath the main top or is made as a loose leaf being placed on two extendable rails. The first principle has the disadvantage of causing an economically incorrect position during placement of the leaf as the back is twisted when reaching in to place the leaf. Alternatively, it requires two people working from each side of the main top.

The second principle provides a more economically advantaged position during exten- sion of the table, but due to the placement in one end, the leaf will often be relatively small compared to the first principle mentioned above as the leaf is only supported by table legs in one end, which limits the length of the leaf, and/or the weight of the construction will be too heavy.

DE 20 2007 012 099 discloses a principle according to which, the leaf is placed in one end and comprises a foldable leaf placed at the one end of the main top. When the leaf is to be utilised, it requires lifting of both the frame and one set of table legs, and the frame with the leaf is pulled out to uncover the leaf placed underneath the main top and unfolded subsequently. This causes ergonomically undesirable movements due to the necessary lifting of the table legs, the frame, the leaf and part of the main top.

DE 20 2010 001 714 discloses an extension table also placing the leaf at one end of the main top. The leaf is pulled out by means of a complicated pulley system, and the top itself is a two-top hinged arrangement causing ergonomically undesirable lifting movements when standing at the head of the table. Another possibility is for one to move to the long side and do a stretching movement across the two-piece leaf to unfold it. This is also ergonomically undesirable.

Disclosure of the Invention One aspect of the invention is to provide a new construction of an extension table solving at least one of the problems mentioned in the prior art or at least providing a useful alternative.

According to the first aspect of the invention, an extension table is provided as de- scribed in the technical field, where also the first rail comprises first means arranged to engage with movable means belonging to the third rail, the second rail comprises second means also arranged to engage with the movable means, by which movement of the movable means, the first and second rails slide away from each other to a second position different from the first position, by which movement, the main top and the leaf move away from each other, and in that the leaf comprises three top parts, a first top leaf, a second top leaf and a third top leaf, said second top leaf being connected to the first and third top leaf by the folding means.

Due to the leaf being pulled out at one end of the main top, this construction achieves a more ergonomically desirable handling when the table is pulled out compared to the constructions, where the leaf is placed in the middle of a separable main top. As both the leaf and the main top move relative to the table legs it is furthermore achieved that the leaf will be supported not only by the rail it is placed on, but the table legs/support frame will also have a supportive effect on the middle part of the leaf. This provides a more stable construction than prior art, where the table legs support one end part of the leaf and not the middle of the leaf as in this case. Furthermore, the leaf may be quite a bit longer than what is seen in for example the above-mentioned German prior art, i.e. up to 40-60 pet. of the length of the main top and preferably around 50 pet. Due to the leaf being constructed as mentioned, an er- gonomically desirable lift is also achieved when the leaf is up to 60 pet. of the length of the main top.

The width of the leaf may correspond to the width of the main top or if desired, be wider than this. Typically, the leaf is rectangular or square, but other geometrical construc- tions might be relevant. For example, said leaf may be circularly shaped in the free end of the head of the table and/or be rounded along the sides.

Likewise, the main top is typically rectangular or square, but it may also have various geometrical shapes, like elliptical or circular. Essentially, the two end parts adjacent each other coming from the main top and the leaf, respectively, are congruous so that when they lock together, they form a continuous surface.

The leaf comprises three top parts, a first top leaf, a second top leaf and a third top leaf, said second top leaf being connected to the first and third top leaf by the folding means. Hereby, a desirable dimension of the leaf is achieved so that in its first position, the leaf may be hidden in a cavity underneath the main top and subsequently unfolded to a dimension, where the width corresponds at least to the width of the main top.

Folding means are meant as being a hinged connection or a folding connection or a pivotal connection; i.e. any connection allowing the first and third top leaf to be placed on top of the second top leaf in the first position of the leaf. The total area of the first and third top leaves is substantially the same as the area of the second top leaf. However, the first and third top leaves may also be shaped so that each their area corresponds substantially to the area of the second top leaf or is slightly less than said se- cond top leaf. In that case, the three top parts are folded so as to being stacked on top of each other by folding means connecting the second top leaf to the first and third top leaves. By area, surface area is understood.

Extension of the table is achieved by slightly pushing the main top mounted on a cou- pie of rails axially slidable compared to a fixed rail, thereby uncovering the subjacent leaf being pulled out subsequently. The synchronous extension taking place moves the main top to one side while the leaf itself is moved to the other side. The underframe is fixed as it is mounted to the stationary rail. After extension, the leaf is unfolded, and due to the construction of the extension table the user may remain at the head of the table and does not need to move to the long side. When standing at the head of the ta- ble, an economically desirable lift is achieved during unfolding of the leaf due to the three-part construction. In unfolded state, the leaf will normally have the same width as the main top.

However, it is possible to construct leaves where the width of the leaf differs from the width of the main top: either wider or narrower.

Subsequently, the leaf is pushed towards the main top locking together with said main top. Preferably, the main top itself is made in one piece and cannot be separated, thus appearing as an unbroken surface.

In a further preferred embodiment, the leaf is folded in its first position so as to comprise a first surface area.

In a preferred embodiment of the invention, the first and third tops are situated between the second surface of the main top and the surface of the second top - the bearing surface - facing the second surface of the main top, said first and third tops substantially covering the bearing surface.

Thereby it is achieved that the leaf may be situated in a small cavity and when unfold- ed, said leaf corresponds substantially to the width of the main top.

In a preferred embodiment of the invention, the main top is mounted to the first rail so that the main top is immovable relative to said first rail. Thereby maximum stability of the main top is achieved.

In a preferred embodiment of the invention, the movable means comprise a gear wheel ratably arranged in the third rail means, said gear wheel engaging with the first and second means, said first means comprising a rack, and said second means comprising a rack. Thereby a suitable and simple construction is achieved for a synchronous extension allowing the main top and leaf to move at the same time opposite one another and mainly at the same speed. This depends on the gear ratio between the gear wheel and the rack.

In a further embodiment of the invention, the leaf comprises a lifting system and by activation of said lifting system, the leaf is moved into a third position different from the first and the second positions. This construction renders it possible to lift up the leaf by minimal physical effort from the cavity defined by the rails to a position above the upper edge of the rails so that the first and third top leaves can be unfolded and the leaf achieve the same width as the main top. Thus, the third and first top leaves are resting their undersides on the upper surface of the rails, thereby levelling the leaf with the main top.

In a further embodiment of the invention, the lifting system comprises leaf springs, said leaf springs being arranged underneath the second top part and being arranged so as to exert a force thereon, which is smaller than the force exerted by the weight of the leaf.

In a further preferred embodiment of the invention, the leaf comprises a lifting system, said lifting system comprising pivotable levers, said levers being pivotally mounted to the second rail in one end, and in the opposite end pivotally mounted to the second top of the leaf. By activation of said lifting system, the leaf is placed in a third position dif- ferent from the first and second position.

This construction is a preferred way of constructing the lifting system.

In a further preferred embodiment of the invention, the extension table comprises a locking system for locking the main top and the leaf together, said leaf being in a fourth position different from the first, second and third positions prior to the locking.

Thereby, it is achieved that the leaf and the main top are not unintentionally separated.

In a further preferred embodiment of the invention, the locking system comprises two locking plates connected to each other by a connecting rod mounted to the main top or the leaf, said two locking plates being arranged by means of the connecting rod so as to move synchronically, and by means of the locking means, the main top and the leaf are arranged so as to lock together. Thereby, it is achieved that the locking of the leaf to the main top is stable and that the locking may be activated from both sides as the connecting rod causes one locking plate to be activated when the other locking plate is turned so as to lock the leaf and main top together. In a further preferred embodiment of the invention, the locking means comprise a pawl and a recess arranged so as to grip a pin on the oppositely placed main top or leaf when being activated.

In a further preferred embodiment of the invention, the extension table comprises a stabilising system, said stabilising system being arranged so as to stabilise the leaf against deflection by means of stabilisation means, when said leaf is subjected to impact force on the first, second and third top part surfaces in a position - fifth position - where an adjoining table top is procured. Thereby, an adjoining and stable table top is achieved.

In a further preferred embodiment of the invention, the stabilising system comprises at least one stabilising pawl protruding from the leaf or the main top, said stabilising pawl sliding in the fifth position into a stabilising recess on the opposite main top or leaf.

In a further preferred embodiment of the invention, the extension table is made of wood, for example beech, oak, pine or cherry tree.

In addition, the invention relates to a method for extension of a leaf in an extension ta- ble., where the main top and the leaf are moved from a reciprocal first position to a second position, by which movement, the main top and the leaf are moved away from each other, where in its second position, the leaf is exposed and accessible, and in that a lifting system is activated, whereby said leaf is levelled with the main top in a third position, and where the leaf is unfolded to a fourth position, whereby the area of the leaf changes from a first surface area to a second surface area, and in that the main top and the leaf lock together in a fifth position for procuring a one-piece table top. In a further preferred embodiment of the invention, the width of the leaf in the third, fourth and fifth positions is the same as the width of the main top.

In a further preferred embodiment of the invention, the support frame comprises table legs shaped as columns or angular profiles, T-shaped support elements or U-shaped support elements.

Brief Description of the Drawina(s)

The invention is explained in detail below with reference to the drawing(s), in which Fig. 1a shows an extension table according to the invention in perspective view and in its first position.

Fig. 1 b shows an X-ray picture of the table top shown in Fig. 1 a. Fig. 2a shows an extension table according to the invention in perspective view in its second position, where the leaf is unfolded.

Fig. 2b shows an X-ray picture of the table top shown in Fig. 2a. Fig. 3a shows a rack in a rail that by cooperating with a gear wheel provides a synchronous oppositely directed movement of the main top and the leaf.

Fig. 3b shows a gear wheel in a third rail arranged to engage with the rack shown in Fig. 3a.

Fig. 4a shows an extension table according to the invention in perspective view and in a third position, where the leaf is lifted out from its cavity.

Fig. 4b shows an X-ray picture of the table top shown in Fig. 4a. Fig. 5 shows an extension table according to the invention in perspective view and in its fourth position, where the leaf is unfolded.

Fig. 6 shows an extension table according to the invention in perspective view and in its fifth position, where the leaf and the main top are locked together as to provide an adjoining table top.

Fig. 7 shows a lifting means for lifting the leaf from its second position to its third position.

Fig. 8 shows a locking system for joining the main top and the leaf in the fifth position.

Fig. 9a shows a stabilising system for stabilising the leaf. Fig. 9b shows the relation between the head of the table and the short side of the main top and the short side of the leaf and the relation between the stabilising system and the locking system.

Fig. 9c shows the leaf and main top assembled with the stabilising system and locking system activated.

Detailed description of the Invention

Figs. 1 a and 1 b show an extension table according to the invention seen in perspective view and the top shown as an X-ray picture. The extension table 1 comprises a main top 2 comprising a plane upper surface, the first surface 3, and an opposite plane surface, second surface 4. The extension table 1 is supported by a support frame 10 shaped herein as a rectangular frame, but it could be shaped as square profiles, columns, T-shaped support means/elements. The support frame 10 is fastened to a rail, the third rail 11 , which remains stationary during the function and various positions of the table, i.e. immovable. Underneath the main top 2, the leaf 6 is placed; said leaf 6 being placed in a cavity 36 underneath the second surface 4 of the main top 2.

The leaf 6 comprises a first top leaf 20, a second top leaf 21 and a third top leaf 22. The first and third top leaves 20, 22 are placed between the second surface 4 of the main top 2 and the upper surface of the second top leaf 21 - the bearing surface 23 - said upper surface turning towards the second surface 4. The surface area of the first top leaf 20 and the third top leaf 22 is substantially identical with the surface area of the second top leaf 21. The top leaves are rectangular, and the first and third top leaves 20, 22 are hinged and/or foldably connected to the subjacent second top leaf 21 by hinge elements called folding means 16, not shown in the Fig.

Furthermore, the leaf 6 comprises a lifting system 26 fastened to the longitudinal edges of the leaf and described in more detail subsequently. By means of the lifting system 26, the leaf 6 is fastened to a rail, the second rail 9, shaped as two parallelly extending square profiles. The surface of the rail 9 faces the stationary rail, the third rail 11 , i.e. opposite the surface to which the leaf 6 is fastened, and may be moved relative to said stationary rail. A first rail 5 is placed on the outer surface of the third rail 11 , said first rail 5 being fastened to the main top 2 and said first rail 5 being slidable relative to the stationary third rail 11. Further, the first rail 5 comprises two parallel and substantially square cross section profiles placed on the exterior of the stationary rail 11. The rail is formed in connection with a synchronous-active pull, in this case a gear wheel. Said gear wheel is rota- bly/pivotably arranged in the first rail 11 and engages with the slidable rails, first rail 5 and second rail 9. Racks are arranged in a recess in said rails, said racks engaging with the teeth of the gear wheel.

Figs. 2a and 2b show the extension table 1 according to the invention, where the leaf 6 is pulled into its second position, i.e. exposing the first top leaf 20 and the third top leaf 22. The extension is provided by a slight push on the main top 2 resulting in an end piece 48 being exposed, said end piece 48 being connected to the second rail /rail pair 9, to which the leaf 6 is attached. By pulling the end piece 48, the main top 2 is moved opposite the puling movement of the leaf, whereby extension of the table takes place, while the support frame 10 fastened to the third rail /rail pair 1 1 remains in the same place. By extension of the leaf 6, the leaf 6 is removed from the cavity 36 underneath the second surface 4 of the main top 2.

Figs. 3a and 3b show the movable means 13 and the first and second means 12, 14 shaped as a gear wheel 24 and racks 25, respectively. The racks 25 are placed in the first rail /rail pair 5, which is fastened to the main top, and in the second rail/rail pair 9 fastened to the leaf. The rack 25 is placed in a recess 37, and parallel with this recess in the same surface, a further recess 37 is placed securing a correct placement be- tween the rails by means of known key and slot arrangements. The gear wheel 24 is placed in the third rail 11 exposing the teeth of the gear wheel on each side of the surface of the square profile facing the first rail and the second rail, respectively. On one side, the gear wheel engages with the first rail, and on the other side, it engages with the second rail, and by turning/rotating around its axis of rotation caused by pulling the leaf and thereby the second rail, the oppositely synchronous movement of the first rail and thereby, the main top and leaf are moved opposite one another at the same speed.

Thereby, the support frame comprising two separate units will be in a centre area of the main top as regards the first unit and in a centre area of the leaf as regards the second unit when the tops have reached their final position for providing an adjoining table top. The reciprocal speed moving the two tops apart may be adjusted by increasing the distance between the teeth in the one rack. If the distance is increased by factor 2, the top with said rack will move at half the speed compared to the other top.

Figs. 4a and 4b show the extension table according to the invention in a third position, where the leaf is lifted from its cavity by means of a lifting system 26. In order to decrease the force lifting the leaf, a leaf spring 34 is placed on the underside of the lower surface of the second top leaf 21 , just as leaf springs 34 are placed on the upper sur- faces of the first and third top leaves decreasing the force of both lifting and unfolding the tops. The first and third top leaves 20, 22 are fastened by hinges to the second top leaf 21 abutting the bearing surface 23 of said second top leaf. The hinges are fastened in cuts 38 for said hinges along the longitudinal sides of the top leaves. In principle, the lifting system 26 explained in more detail with reference to Fig. 7 comprises levers 27 placed with mounting along the longitudinal sides of the top leaves. Said levers 27 ensures by means of a simple principle of turning the lever with a first pivotable part 28 along first lever and opposite said lever a second pivotable part 29 that the leaf 6 is lifted uniformly from its second position to its third position. In its third position, the leaf has a first area. In the shown example, the leaf is a previously mentioned a foldable top.

Fig. 5 shows the extension table 1 according to the invention in perspective view and in its fourth position, where the leaf 6 has reached its maximum surface area, the second surface area, in that the first top leaf 20 and the third top leaf 22 are unfolded and are level with the second top leaf 21. Furthermore, the surface of the leaf is levelled with the first surface 3 of the main top.

Fig. 6 shows the extension table 1 in its fifth position, where the leaf 6 and the main top 2 are pushed together so that one of the end surfaces of the leaf 6 abuts one of the end surfaces of the main top so as to provide an end surface boundary 39 making the extension table appear as an adjoining table top. To ensure that the leaf and the main top are not separated, a locking system 31 is provided on the underside of the leaf 6 and the main top 2. Said locking system will be explained in more detail with reference to Fig. 8.

Fig. 7 shows a lifting system 26 lifting the leaf 6 from its second to its third position. Said lifting system 26 comprises a longitudinal rod 41 fastened to the second rail /rail pair 9, in which ends a rod 27 is provided. Said levers 27 are pivotably connected in first end 28 to a mounting 40 fastened to the leaf 6, and the second end 29 of the lever 27 is pivotably connected to the rod 41.

The rods are dimensioned so that in unfolded position, the leaf is horizontally levelled with the upper surface of the upper surface of the main top. Preferably, there are four levers 27 placed with two levers 27 on each their second rail.

Fig. 8 shows a locking system for connecting the main top 2 and the leaf 6. Said locking system comprises a connection rod 46 fastened by means of a transverse mounting 47 to the second surface 4 of the main top 2 parallel to the end abutting the leaf 6. A locking plate 42 is placed at the ends of the connection rod 46, said locking plate 42 comprising a pawl 43, and a recess 44 is provided between the pawl 43 and the rest of the top. A place pin 45 for turning/catching the top is placed on the surface of the locking plate 42 facing the support frame so that when the top pivotably mounted on the rod 46 is turned, the plate 42 in the other end will also turn. Similar to the first top leaf, the pawl of the plate 42 will grip a pin 49 placed on the underside of the leaf. In this way, locking of the two tops provides an adjoining table top.

In the show example, the table top is shown as a rectangular/square adjoining table top, but in principle it could be cylindrical, elliptical or kidney-shaped. In principle, the table top could have any shape, and the end surface boundary 39 between the leaf 6 and the main top 2 could also be shaped in many different ways. However, the two sur- faces from the main top 2 and the leaf 6 abutting each other must be complementary thereby making the connected top seem adjoined. The leaf is shown as a foldable top, but could in principle comprise a non-foldable leaf being narrower than the main top itself. Further, the first and third top leaves could be shaped differently, e.g. as a semi- circular-shaped top, the essential part being that there is room for said tops in the cavity underneath the main top.

Fig. 9a shows the leaf 6 and the main top 2 seen from below with the locking system 31 and a stabilising system 50 mounted to this surface. The locking system 31 is ex- plained above. The stabilising system 50 comprises a stabilising pawl 51 preferably shaped in metal protruding perpendicular from the short side of the leaf 6. Said stabilising pawl 51 engages with a stabilising recess 52 in the main top 2 so that when the two surfaces of the main top 2 and the leaf 6, respectively, are pressed against each other, the stabilising recess 52 will encircle the stabilising pawl 51. In the shown embodiment the recess 52 is covered by a cover plate 53, but the recess could also be provided by boring out the table top. On the surface of the stabilising pawl 51 facing the bottom of the recess, said surface has a wedge-shaped underside 54 ensuring a good fitting in the recess itself when the stabilising pawl engages resiliently with the recess. Fig. 9b shows a stabilising system comprising two stabilising pawls 51 and two stabilising recesses 52 symmetrically placed around the centre line of the leaf 6 and the main top 2.

Fig. 9c shows the leaf 6 pushed so as to abut the end surface of the main top 2 and the locking system 31 with its pawl gripping a pin 49 placed on the underside of the leaf 6, and where a stabilising system 50 is activated by the stabilising pawl 51 being arranged in the stabilising recess 52. List of reference numerals

1 Extension table

2 Main top

3 First surface

4 Second surface

5 First rail

6 Leaf

7 First position

8 Connection means

9 Second rail

10 Support frame

11 Third rail

12 First means

13 Movable means

14 Second means

15 Second position

16 Folding means

17 Surface area of the leaf 18 First surface area

19 Second surface area

20 First top leaf

21 Second top leaf

22 Third top leaf

23 The bearing surface

24 Gear wheel

25 Rack

26 Lifting system

27 Pivotable levers 28 One end lever

29 Opposite end lever

30 Third position

31 locking system

32 Fourth position 33 Adjoining table top 34 Leaf springs 35 Table legs, T-shaped support elements, U-shaped support elements

36 Cavity

37 Recess

38 Cut for hinge

39 End surface limit

40 Mounting for 26

41 Rod for 26

42 Locking plate

43 Pawl

44 Recess for 42

45 Pin

46 Connection rod

47 Mounting for fastening

48 End piece

49 Pin

50 Stabilising system

51 Stabilising pawl

52 Stabilising recess

53 Cover plate

54 Wedge-shaped underside of stabilising pawl