EXTENDABLE TABLE AND CONNECTED METHOD

Abstract

 Extendable table comprising a fixed frame (14) provided with first fixed longitudinal cross-pieces (19), and associated with its own legs (16) and with a fixed main top (12), and a mobile frame (15) associated with its own legs (17) and provided with second mobile longitudinal cross-pieces (22) with which a mobile extension top (13) is associated. The second mobile longitudinal cross-pieces (22) are able to slide along the first fixed longitudinal cross-pieces (19), to take the mobile extension top (13) from a retracted position in which it is located under the fixed main top (12), to an extended position in which the mobile extension top (13) is located adjacent and, by means of positioning means (43), coplanar to the fixed main top (12). The extendable table (10) comprises actuator means (25) configured to move the mobile frame (15) in a motorized manner with respect to the fixed frame (14), and to determine the sliding of the second mobile longitudinal cross-pieces (22) along the first fixed longitudinal cross-pieces (19).

Description

FIELD OF THE INVENTION

[0001] The present invention concerns an extendable table provided with a mechanism to move an extension top with respect to a main top.

[0002] The present invention also concerns the functioning method of the extendable table.

[0003] Here and hereafter in the description and claims, the term "main top" refers to the table top in its non-extended configuration.

BACKGROUND OF THE INVENTION

[0004] Various types of extendable tables are known, in which there is a main top and at least one extension top, mobile between a first position, in which the extension top is positioned retracted under the main top, and at least a second position, in which the extension top is disposed adjacent and coplanar, for example, to the short side of the main top.

[0005] Extendable tables are substantially of two types: those with a fixed frame in which the legs maintain the same position, and those in which some of the legs (normally two) can be moved away from the others, which remain fixed.

[0006] One disadvantage of known extendable tables is that the extension top must be extracted manually by a user. This manual drive is inconvenient, complicated, requires a lot of attention and usually requires a physical effort and precision on the part of the user.

[0007] Furthermore, the manual drive requires the user to operate directly on the extendable table to perform this operation.

[0008] As indicated, extendable tables are also known that do not move the frame, but only the one or more extension tops. One disadvantage of these extendable tables is that the extension tops are positioned cantilevered with respect to the frame of the extendable table, and cannot support heavy loads. For this purpose, the reach of the top must be reduced.

[0009] Another disadvantage of this second solution is that the space between the legs located under the top of the extendable table does not vary between the open configuration and the closed configuration, so that a user can have difficulty positioning his/her legs under the table top.

[0010] A peninsula element is also known from document JP-A-2.987.413, associated with a piece of furniture and which is provided with a main top attached to the piece of furniture and with an extension top sliding with respect to the main top to move to a retracted position under the main top and an extended position in which it is located adjacent and coplanar to the main top.

[0011] The extension top is provided in correspondence with its edge that, during use, is more external with a support element that supports the extension top with respect to a support plane, such as the floor.

[0012] In correspondence with one of its ends positioned on the floor, the support element is provided with a motor member also located resting on the floor by means of one or more support wheels. By driving the motor member, the action of the support wheels on the floor also determines the simultaneous translation of the extension top with respect to the main top.

[0013] This solution, however, is particularly bulky and difficult to apply in extendable tables that can be used in the home.

[0014] There is therefore a need to make an extendable table which overcomes at least one of the disadvantages of the state of the art.

[0015] The purpose of the present invention is to provide an extendable table that allows to move, without any direct manual intervention, at least one mobile extension top from a closed configuration, in which it is located under the main top, to an open configuration, in which it is located adjacent to the main top, and in continuation of it.

[0016] Another purpose of the present invention is to provide an extendable table in which the reciprocal position of the table legs relates to the conditions of use of the upper top.

[0017] Another purpose is to perfect a method to open/close the extendable table.

[0018] Another purpose is to be able to drive the opening/closing of the extendable table also from remote positions.

[0019] Another purpose is to equip the extendable table with its own energy supply means, for example a battery, advantageously rechargeable.

[0020] Another purpose is to provide an extendable table in which the drive mechanism can also be applied to already existing extendable tables, without requiring substantial constructional modifications.

[0021] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

[0022] The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

[0023] In accordance with the above purposes, the present invention concerns an extendable table comprising a fixed frame associated with its own legs and with a main top, and a mobile frame, associated with its own legs and provided with second mobile longitudinal cross-pieces with which a mobile extension top is associated. The second mobile longitudinal cross-pieces are able to slide along the first fixed longitudinal cross-pieces.

[0024] In accordance with one aspect of the present invention, the extendable table comprises actuator means connected to the fixed frame and to the mobile frame and configured to move the mobile frame in a motorized manner with respect to the fixed frame, and to determine the sliding of the second mobile longitudinal cross-pieces along the first fixed longitudinal cross-pieces. Moreover, the extendable table, according to the invention, comprises positioning means associated with the mobile frame and with the mobile extension top and configured to take the mobile extension top from a retracted position in which it is located under the fixed main top, to an extended position, in which the mobile extension top is located adjacent and coplanar to the fixed main top.

[0025] According to possible embodiments, the actuator means can be configured to drive the positioning means and to move the mobile frame with respect to the fixed frame along a longitudinal axis of the extendable table, thus taking the mobile extension top from the retracted position to the extended position and vice versa.

[0026] According to a variant of the invention, the positioning means comprise cam means, suitable to automatically position, in a high or a low position, the mobile extension top when this or that positioning of the extendable table is required.

[0027] According to another variant of the invention, means are also provided that, in the opening step, position the mobile extension top adjacent and coplanar to the fixed main top.

[0028] According to another variant of the invention, means are also provided that, in the closing step, reposition the mobile extension top in the fixed frame so that it does not interfere with the main top even though it is inserted and positioned under it.

[0029] It is within the spirit of the invention to provide the table connected to a power source that feeds the actuator means electrically.

[0030] A variant provides that the power source is on board the table and is, for example, a battery to accumulate electric power.

[0031] According to a variant, means are provided configured to detect that the mobile extension top has been positioned in a retracted or extended position.

[0032] It is also a purpose of the present invention to provide a control and command device.

[0033] Another variant provides that the control and command device is associated with detection means of the components and is configured to interrupt functioning if and whenever a component is not in the expected position.

[0034] Another variant provides a command switch on board the table.

[0035] Another variant provides means, even mobile, to activate the control and command device to perform the desired function.

[0036] Embodiments of the present invention also concern a method to open/close an extendable table as identified above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

• fig. 1 is a perspective view of an extendable table in accordance with the present invention, in a closed configuration;
• fig. 2 is a view from above of fig. 1;
• fig. 3 is a cross section view enlarged along the line III-III of fig. 2;
• fig. 4 is a view from under of fig. 1;
• fig. 5 is a perspective view of the extendable table in fig. 1 in an open configuration;
• fig. 6 is a view from above of the extendable table in fig. 5;
• fig. 7 is a cross section view enlarged along the line VII-VII of the extendable table in fig. 6;
• fig. 8 is a view from under of fig. 5.

[0038] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

[0039] We must clarify that in the present description and in the claims the terms lower, upper, above, and under, with their declinations, have the sole function of better illustrating the present invention with reference to the drawings and must not in any way be used to limit the scope of the invention itself, or the field of protection defined by the claims.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

[0040] With reference to the attached figs. 1-8, an extendable table according to the present invention is indicated by the reference number 10.

[0041] The extendable table 10 extends along a longitudinal axis Z and comprises a fixed frame 14 and a mobile frame 15.

[0042] The fixed frame 14 and the mobile frame 15 are each associated with respective support legs 16 and 17 respectively.

[0043] The fixed frame 14 is associated with a main top 12, normally fixed.

[0044] The mobile frame 15 has an extension top 13 which is mobile with respect to the fixed frame 14.

[0045] In the attached drawings, the fixed main top 12 and the mobile extension top 13 have been shown in broken lines to show the underlying components.

[0046] The legs 16 of the fixed frame 14 are connected to each other by at least one first orthogonal cross-piece 18 which reciprocally positions and distances them and makes them stable.

[0047] The fixed frame 14 comprises a pair of first fixed longitudinal cross-pieces 19 located parallel to each other and parallel to the longitudinal axis Z.

[0048] The first fixed longitudinal cross-pieces 19 can be reciprocally distanced by one or more bars 40, in the case shown here also by the first orthogonal cross-piece 18.

[0049] In possible solutions, each of the legs 16 can be stably associated with a respective first fixed longitudinal cross-piece 19.

[0050] Each first fixed longitudinal cross-piece 19 can be associated with guide means 23 which support and position linearly, along the longitudinal axis Z, a respective second longitudinal mobile cross-piece 22 associated with the mobile frame 15.

[0051] The second mobile longitudinal cross-pieces 22 cooperate with end-of-travel elements 24 associated with the first fixed longitudinal cross-pieces 19, and configured to define the maximum translation of the second mobile longitudinal cross-pieces 22 with respect to the first fixed longitudinal cross-pieces 19.

[0052] According to some solutions, the guide means 23 are able to abut with the end-of-travel elements 24 associated with the first fixed longitudinal cross-pieces 19 (fig. 8) to take the extendable table 10 into its extended position; they are also able to abut with the first orthogonal cross-piece 18 (figs. 1-3) to take the extendable table 10 into a retracted position.

[0053] The end-of-travel elements 24 can be mechanical or electric.

[0054] The second mobile longitudinal cross-pieces 22 are connected to each other by a second orthogonal cross-piece 21 located orthogonally to the longitudinal axis Z.

[0055] The legs 17 of the mobile frame 15 can be connected to the second orthogonal cross-piece 21.

[0056] This means that, by moving the second mobile longitudinal cross-pieces 22 with respect to the first fixed longitudinal cross-pieces 19, the legs 17 of the mobile frame 15 also move with respect to the legs 16 of the fixed frame 14.

[0057] The sliding of the second mobile longitudinal cross-pieces 22 with respect to the first fixed longitudinal cross-pieces 19 determines the positioning of the mobile extension top 13 in a retracted position in which it is located under the fixed main top, and an extended position, in which the mobile extension top 13 is located adjacent to the fixed main top 12.

[0058] According to possible embodiments, the legs 17 of the mobile frame 15 can be provided with wheels 17a, able to facilitate their sliding on a support plane.

[0059] According to possible embodiments, the fixed main top 12 is advantageously integrally associated with the first fixed longitudinal cross-pieces 19 by means of fixed supports 20, in this case consisting of four fixed supports 20.

[0060] According to possible embodiments, the mobile extension top 13 is associated with the second mobile longitudinal cross-pieces 22 by support elements 20a. The support elements 20a are mobile in a direction orthogonal to the mobile extension top 13 between a first height (fig. 3), corresponding to the retracted position, and a second height (fig. 7) corresponding to the extended position.

[0061] Positioning means 43 are associated with the mobile extension top 13 and with the mobile frame 15, in particular with the second mobile longitudinal cross-pieces 22, and are provided to take the mobile extension top 13 from a height under the fixed main top 12 in the retracted position, to a height coplanar with the fixed main top 12, in the extended position of the extendable table 10.

[0062] The positioning means 43 comprise a mobile slider 30 installed sliding on the second mobile longitudinal cross-pieces 22 and movement means 37, which in this case are cam means 37, associated with the mobile slider 30 and with the mobile extension top 13 and provided to lift or lower the mobile extension top 13 under or coplanar with the fixed main top 12, by sliding the mobile slider 30 along the second mobile longitudinal cross-pieces 22.

[0063] In accordance with variant embodiments, not shown, the movement means 37 can also comprise articulated mechanisms, levers, sliding guides, or similar and comparable components, configured to lift or lower the mobile extension top 13.

[0064] The mobile slider 30 cooperates with support elements 36 of the mobile extension top 13.

[0065] The second mobile longitudinal cross-pieces 22 also have guide means, on which a mobile slider is slidable, in a direction parallel to the longitudinal axis Z.

[0066] The mobile slider 30 can comprise two lateral cross-pieces 31 each sliding along a respective one of the second mobile longitudinal cross-pieces 22 and a base cross-piece 32 which connects the lateral cross-pieces 31 with each other.

[0067] According to a possible aspect of the present invention, actuator means 25 are associated with the fixed frame 14 and with the mobile frame 15 to determine the motorized movement of the mobile frame 15 along the longitudinal axis Z of the extendable table 10 determining the sliding of the second mobile longitudinal cross-pieces 22 along the first fixed longitudinal cross-pieces 19.

[0068] According to some embodiments of the present invention, the actuator means 25 are configured to move both the mobile frame 15 with respect to the fixed frame 14 and also to move the mobile slider 30 along the second mobile longitudinal cross-pieces 22.

[0069] According to a variant, the actuator means 25 can comprise a control and command device 39 which regulates and controls the functioning of the extendable table 10.

[0070] In accordance with a possible solution, the actuator means 25 can comprise a linear actuator 44 connected with at least a first element 27 to the fixed frame 14 and with a second element 26 to the mobile slider 30. The linear actuator 44, moreover, extends axially, for example along the longitudinal axis Z, along the longitudinal extension of the extendable table.

[0071] In accordance with possible solutions, the first element 27 and the second element 26 are selectively movable reciprocally toward/away from each other during the movements of the mobile frame 15 with respect to the fixed frame 14.

[0072] According to a possible solution, the actuator means 25 comprise a motor 42, for example an electric motor, governed by the control and command device. The motor 42 can be associated with the first element 27 and with the second element 26 to allow their reciprocal movement.

[0073] In accordance with the embodiments shown in the attached drawings, the linear actuator 44 comprises a longitudinal sleeve that defines the first element 27 and a rod that defines the second element 26 installed slidable with respect to the longitudinal sleeve 27. The motor 42 can be associated with the rod 26 to make it rotate and to determine the axial movement of the latter.

[0074] According to possible embodiments, the actuator means 25 can be connected to an energy source, for example to an electrical network.

[0075] According to a variant, the extendable table 10 comprises an energy accumulation battery, for example rechargeable, associated with the actuator means 25.

[0076] According to a variant, the extendable table 10 can comprise command means 41 of the control and command device 39 and therefore means to activate the actuator means 25 to perform the desired function of extending or closing the extendable table 10 in a controlled or automatic manner.

[0077] The command means 41 can be of any type.

[0078] According to a variant, the command means 41 can be installed on board the extendable table 10 and comprise, for example, one or more activation/deactivation buttons, that is, a push-button panel.

[0079] According to a variant, the command means 41 are portable or can be driven from remote positions, and possibly of the wireless type.

[0080] The longitudinal sleeve 27 can be supported by the bar 40, associated for example with the first fixed longitudinal cross-pieces 19.

[0081] The second element 26 of the linear actuator 44 is connected to the mobile slider 30, for example to its base cross-piece 32, while the longitudinal sleeve 27 is associated with the fixed frame 14.

[0082] The drive of the motor 42 determines the rotation of the rod, that is, of the second element 26, of the linear actuator 44 which, moving with respect to the longitudinal sleeve, or to the first element 27, also moves the mobile slider 30 which slides on the guide means of the second mobile longitudinal cross-pieces 22.

[0083] The second element 26, that is, the rod, is also connected to a transverse element 29 which reciprocally connects the second mobile longitudinal cross-pieces 22.

[0084] In this specific case, it can be provided that the second element 26 is positioned through, and able to slide through a hole made in the transverse element 29.

[0085] In particular, the transverse element 29 is positioned with respect to the rod 26 so that the base cross-piece 32, also fixed to the rod 26, is located between the longitudinal sleeve 27 and the transverse element 29.

[0086] In this way, the second element 26, which has an oblong development, extends beyond the base cross-piece 32 and cooperates with the transverse element 29 associated with the second mobile longitudinal cross-pieces 22.

[0087] The cam means 37 can comprise cams 45 associated with the mobile slider 30, and support elements 36 connected to the mobile extension top 13 and sliding on the cams 45. In particular, the support elements 36 can be positioned resting on a cam surface 45.

[0088] The cams 45 can be installed on lateral cross-pieces 31.

[0089] According to a variant embodiment, the cams 45 can be defined by a suitably shaped groove, or guide, in which at least one of the support elements 36 is slidable. By way of example only, it can be provided that the lateral cross-pieces 31 are provided in their thickness with said grooves or guides in which part of the support elements 36 can be positioned slidable. The grooves define, in fact, a cam to position the support elements 36.

[0090] The cam means 37 are able to perform several functions.

[0091] When the mobile extension top 13 retracts or exits, the cam means 37 position the mobile extension top 13 in a position under the fixed main top 12 but in such a condition that it does not slide on the fixed main top 12.

[0092] Advantageously (fig. 7), the cams 45 can comprise a first segment 37a, in which the support elements 36 can pass from a first height, corresponding to the height of the mobile extension top 13 below and in contact with the fixed main top. 12, as shown in fig. 3, to a second height, corresponding to the height of the mobile extension top 13 when it is under the fixed main top 12 but in such a condition that it does not slide on the fixed main top 12, and vice versa.

[0093] The cams 45 can comprise a second segment 37b, along which the support element 36 can pass from the second height to a third height, corresponding to the height of the mobile extension top 13 when it is planar and adjacent to the fixed main top 12, as shown in fig. 7.

[0094] When the second mobile longitudinal cross-pieces 22 of the mobile frame 15, passing from the retracted position to the extended position, come into contact with the end-of-travel elements 24 (fig. 8), the cams 45, associated with the lateral cross-pieces 31, oblige the support elements 36 to rise, that is, to slide along the second segment 37b until the mobile extension top 13 is positioned at the same height as the fixed main top 12 (fig. 5).

[0095] According to possible embodiments, between the base cross-piece 32 and the transverse element 29 there is a first spring 33, that is, first spring means, which during the step when the table is extended is compressed between the base cross-piece 32 and the transverse element 29, determining a reciprocal sliding of the mobile slider 30 and the second mobile longitudinal cross-pieces 22. This reciprocal sliding also determines the simultaneous sliding of the support elements 36 along the second segment 37b of the cams 45 with consequent lifting of the mobile extension top 13 to put it adjacent and coplanar to the fixed main top 12.

[0096] According to possible embodiments, the rod, that is, the second element 26 of the linear actuator 44, extends longitudinally beyond the transverse element 29 and has a clamping element 28 at its end positioned, during use, between the second orthogonal cross-piece 21 and the transverse element 29.

[0097] Between the clamping element 28 and the cross-element 29 there is a second spring 34, that is, second spring means 34, which during the step when the table is closed is compressed between the clamping element 28 and the transverse element 29.

[0098] This determines the reciprocal sliding of the mobile slider 30 and the second mobile longitudinal cross-pieces 22 and the simultaneous sliding of the support elements 36 along the first segment 37a of the cams 45, with consequent lifting of the mobile extension top 13 to put it in contact with the lower surface of the fixed main top 12 as shown in fig. 3.

[0099] According to possible embodiments, the cams 45 are associated with end-of-travel detectors 38, configured to detect that the positioning has occurred of the mobile extension top 13 in its retracted position or its extended position and to interrupt the functioning of the actuator means 25.

[0100] Advantageously, the control and command device 39 can be associated with the end-of-travel detectors 38 and can be configured to interrupt the functioning of the extendable table 10 if and whenever a component is not in the expected position.

[0101] It is clear that modifications and/or additions of parts can be made to the extendable table as described heretofore, without departing from the field and scope of the present invention.

[0102] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of extendable table, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0103] In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.

Claims

1. Extendable table comprising a fixed frame (14) provided with first fixed longitudinal cross-pieces (19), and associated with its own legs (16) and with a fixed main top (12), and a mobile frame (15) associated with its own legs (17) and provided with second mobile longitudinal cross-pieces (22) with which a mobile extension top (13) is associated, said second mobile longitudinal cross-pieces (22) being able to slide along said first fixed longitudinal cross-pieces (19), characterized in that it comprises actuator means (25) connected to said fixed frame (14) and to said mobile frame (15) and configured to move said mobile frame (15) in a motorized manner with respect to said fixed frame (14), and to determine the sliding of said second mobile longitudinal cross-pieces (22) along said first fixed longitudinal cross-pieces (19), and in that it comprises positioning means (43) associated with said mobile frame (15) and with said mobile extension top (13) and configured to take said mobile extension top (13) from a retracted position in which it is located under said fixed main top (12), to an extended position, in which said mobile extension top (13) is located adjacent and coplanar to said fixed main top (12).

2. Extendable table as in claim 1, characterized in that said positioning means (43) comprise a mobile slider (30) installed sliding on said second mobile longitudinal cross-pieces (22), and movement means (37) associated with said mobile slider (30) and with said mobile extension top (13) configured to lift or lower the latter under or coplanar with said fixed main top (12) by sliding said mobile slider (30) along said second mobile longitudinal cross-pieces (22).

3. Extendable table as in claim 2, characterized in that said actuator means (25) are configured to move both said mobile frame (15) with respect to said fixed frame (14), and also to move said mobile slider (30) along said second mobile longitudinal cross-pieces (22).

4. Extendable table as in claim 2 or 3, characterized in that said actuator means (25) comprise a linear actuator (44) connected with at least a first element (27) to said fixed frame (14) and with a second element (26) to said mobile slider (30), and in that said linear actuator (44) extends axially along the longitudinal extension of said extendable table.

5. Extendable table as in claim 4, characterized in that said mobile slider (30) comprises two lateral cross-pieces (31) each sliding along a respective one of said second mobile longitudinal cross-pieces (22), and one base cross-piece (32) that connects said lateral cross-pieces (31) with respect to each other, and in that said second element (26) of said linear actuator (44) is connected to said mobile slider (30).

6. Extendable table as in claim 5, characterized in that said second element (26) has an oblong development, extends beyond said base cross-piece (32) and cooperates with a transverse element (29) associated with said second mobile longitudinal cross-pieces (22), and in that first spring means (33) are interposed between said base cross-piece (32) and said transverse element (29).

7. Extendable table as in claim 6, characterized in that said second element (26) extends beyond said transverse element (29) and has a clamping element (28) at its end, and in that second spring means (34) are interposed between said transverse element (29) and said clamping element (28).

8. Extendable table as in claim 2, characterized in that said movement means are cam means (37) comprising cams (45) associated with said mobile slider (30) and support elements (36) connected to said mobile extension top (13) and sliding on said cams (45).

9. Extendable table as in any claim hereinbefore, characterized in that said actuator means (25) comprise a motor (42) governed by a control and command device (39).

10. Extendable table as in claim 8, characterized in that said cam means (37) have at least two vertical positions, one corresponding to said mobile extension top (13) in a lowered position and one corresponding to said mobile extension top (13) coplanar with said fixed main top (12).

11. Extendable table as in any claim hereinbefore, characterized in that said second mobile longitudinal cross-pieces (22) cooperate with end-of-travel elements (24) associated with said first fixed longitudinal cross-pieces (19), and configured to define the maximum translation of the second mobile longitudinal cross-pieces (22) with respect to the first fixed longitudinal cross-pieces (19).

12. Functioning method of an extendable table that comprises a fixed frame (14) provided with first fixed longitudinal cross-pieces (19), and associated with its own legs (16) and with a fixed main top (12), and a mobile frame (15) associated with its own legs (17) and provided with second mobile longitudinal cross-pieces (22) with which a mobile extension top (13) is associated, wherein said method provides to make said second mobile longitudinal cross-pieces (22) slide along said first fixed longitudinal cross-pieces (19), characterized in that by means of actuator means (25), connected to said fixed frame (14) and to said mobile frame (15), the movement of said mobile frame (15) is commanded in a motorized manner with respect to said fixed frame (14), and the sliding is commanded of said second mobile longitudinal cross-pieces (22) along said first fixed longitudinal cross-pieces (19), and in that during said movement, positioning means (43) associated with said mobile frame (15) and with said mobile extension top (13) take said mobile extension top (13) from a retracted position in which it is located under said fixed main top (12), to an extended position, in which said mobile extension top (13) is located adjacent and coplanar to said fixed main top (12).

13. Method as in claim 12, characterized in that by means of a linear actuator (44) of said actuator means (25), a mobile slider (30) is driven in order to move it along said second mobile longitudinal cross-pieces (22) that slide on guides present in the first fixed longitudinal cross-pieces (19).

14. Method as in claim 13, characterized in that said linear actuator (44) presses against a base cross-piece (32) that connects lateral cross-pieces (31) of said mobile slider (30) with each other, and that slide on guides present in said second mobile longitudinal cross-pieces (22).

15. Method as in claims 13 or 14, characterized in that said mobile slider (30) includes cam means (37) that support support elements (36) of said mobile extension top (13) in the lowered position during the opening step and in the closed table condition.

Drawing