Round extendable table

The present patent application relates to a round table extended by means of an opposite pair of identical foldaway leaves, each of them being shaped as a crescent.

This model of table is an absolute novelty because so far round extendable tables have always had a standard configuration, according to which the top was formed of an opposite coplanar pair of half-tops, shaped as a semicircle, sliding above a support and guide frame, in such a way that, when necessary, they can be moved away to leave a central space free, where to insert one or more rectangular extension boards, each of them having length equal to the diameter of said semicircular half-tops.

On the contrary, in the table according to the invention, the two leaves are placed side by side with the external side of the table, the top of which is formed of a monolithic disk that, when rotated around its centre, causes - thanks to an ingenious mechanism - the translation in opposite direction of two leaves that, as mentioned above, are shaped as a crescent, the internal concave side of which is formed of an arch of circle adapted to perfectly adhere against the border of said monolithic disk when the table of the invention is brought in elongated position.

The same mechanism automatically provides for lowering said central monolithic disk when the leaves have been completely extracted, in such a way that disk and leaves are in coplanar position.

Vice versa, during the retraction of the leaves, the same mechanism provides for raising the central disk in order not to interfere with the approaching travel of the leaves under the disk, where they remain completely concealed and protected at the end of said retraction phase.

The table of invention basically comprises:

- a circular top formed of a monolithic disk; - an opposite pair of identical lateral leaves, of the type that can be concealed under said central top;

- a horizontal frame supported by multiple legs and provided with an opposite pair of parallel tracks;

- two opposite identical slides that support said pair of lateral leaves and slide along said tracks;

- a platform that supports said central top, which is adapted to rotate freely around a vertical axis passing through the center of said monolithic disk;

- an opposite pair of fixed cams adapted to automatically raise and lower said top-holding platform during the retraction and expulsion of said lateral leaves, respectively;

- an opposite pair of connecting-rods, each of them connecting said top- holding platform with one of the two leaf-holding slides, in such a way that the rotation of the platform corresponds to the translation of said slides in opposite direction.

For purposes of clarity, the description of the table of the invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, wherein:

- figs. 1 A and 1 B are axonometric views of the table of the invention in non- extended and extended position, respectively;

- fig. 2 is the same as fig. 1 A, except for it shows the top of the table in raised position to show the actuation mechanism of the two lateral leaves;

- Fig. 3 is an axonometric exploded view of some parts of the table of the invention;

- figs. 4A and 4B are side views of the table of the invention in non-extended and in extended position;

- figs. 5A, 5B and 5C show the opening and closing mode of the extendable table of the invention;

Figs. 6 to 10C refer to a second embodiment of the table according to the invention, which differs from the first one only in the configuration of said rotary top-holding platform and in the configuration of the means adapted to affect the up-down movement of the circular top (1 ). More precisely:

- fig. 6 is an axonometric view of said second embodiment of the table of the invention, with lateral leaves (2) in completely extracted position and top (1 ) raised, in such a way to show the actuation mechanism of the leaves (2) following the rotation of the top (1 ) ;

- Fig. 7 is an enlarged view of a detail of fig. 6 that shows the configuration of said actuation mechanism;

- Fig. 8 is a view of the same actuation mechanism as fig. 6, shown in the position taken when the leaves are completed retracted under the top (1 ); - Fig. 9 is an exploded axonometric view of some parts of the table of the invention according to said second embodiment;

- Figs. 10A, 10B and 10C show the opening and closing mode of said second embodiment of the extendable table of the invention.

Referring to figs. 1 A to 5C, according to a first embodiment, the table (T) of the invention comprises a circular top (1 ) composed of a monolithic disk, and a pair of identical sliding leaves (2) that are stored and concealed under the top (1 ) on diametrically opposite sides when they are not used.

Each of said leaves (2) is shaped as a crescent, the internal concave side of which (2a) is formed o fan arch of circle with same radius as the top (1 ).

Said table (T) also comprises a support frame (3) for indirect support of both the circular top (1 ) and leaves (2).

Said support frame (3) is provided with lower legs for ground support and stabilization.

Referring to figs. 2 and 3, said support frame (3) is formed of a rectangular frame (3a), under which said legs (4) are fixed, whereas two identical cross- pieces (5) are fixed on it on opposite sides, acting as support and guide tracks for two identical leaf-holding slides (6 and 6').

Each slide is formed of a portal-shaped frame that lies on a horizontal plane, which comprises a cross-piece (6a and 6a') and two legs (6b and 6b').

Each cross-piece (5) acts as support and guide for a pair of legs (6b and 6b') that are respectively situated and sliding on opposite sides of the same cross- piece (5). Each slide (6 or 6') is provided with shelves (7) to hold and fix the corresponding leaf (2).

The top (1 ) is held and fixed on a platform that is configured as a cross (8), which is in turn fixed above a coupling pin (9) with vertical axis, which is engaged and rotates inside a collar (10) that is an integral part of said frame (3) and is in particular fixed to said bearing frame (3a).

In fact, said coupling pin (9) not only is free to rotate inside the collar (10) around a vertical axis (Y) passing through the center of the circular top (1 ), but also to make alternate vertical travels according to the same axis (Y), being guided by said collar (10).

The four identical arms (8a,8b,8c and 8d) of said cross (8) protrude from the coupling pin (9) and their protruding sections adhere to the collar (10), at least until said coupling pin (9) is situated at the end of the descending travel, a condition that corresponds to the table in extended position, with leaves (2) coplanar to the top (1 ), as shown in fig. 1 B.

Above said collar (10) a diametrically opposite pair of wedge-shaped cams (1 1 ), in relief, is provided to automatically cause - as illustrated in detail below - the raising and lowering of said cross platform (8) during the retraction and expulsion of the lateral leaves, respectively.

Said cross platform (8) is connected to the two slides (6,6') by means of two connecting-rods (12), each of them being pivoted at one (12a) of the ends (12a,12b) in the central point of the cross-pieces (6a, 6a'), whereas it is pivoted at the other end (12b) to an arm (8a or 8c) of the cross platform (8), as shown in fig. 5C.

From a kinematic viewpoint, it can be said that the platform (8) contributes to form, together with the opposite pair of connecting rods (12), a connecting rod-crank type mechanism, adapted to convert the angular oscillations of the crank, to which the pin (1 ) is fitted, into alternate opposite travels of the leaf- holding slides (6,6').

It must be noted that said connecting rods (12) are pivoted at the opposite aligned pair of arms (8a and 8c), which never interfere - during rotation of the platform (8) - with the cams (1 1 ) adapted to interact only with the other opposite aligned pair of arms (8b and 8d).

Finally, it must be noted that said coupling pin (9) is externally provided with a diametrically opposite pair of notches (13) where the tip of a radial plug (14) is inserted and slides, being inserted through the collar (10).

Each notch (13) comprises a first horizontal section (13a) connected with a second descending section (13b), which is in turn connected with a third horizontal section (13c).

The second descending section (13b) has an inclination angle equal to the one of the wedge-shaped cams (1 1 ), whereas said notch (13) has a total length such to subtend an angle in the center of 180°.

Referring to the set of figs. 5A, 5B and 5C, this description continues with the illustration of the automatic expulsion of the lateral leaves (2) when the top (1 ) is driven into rotation by an angle of 180° around the vertical axis (Y) passing through its center.

In particular, referring to fig. 5A, when the table (T) is not in extended position, as shown in fig. 1 A, the opposite aligned pair of arms (8a and 8c) forms an angle (a) with the axis of symmetry (X) of the crescent-shaped leaves (2).

In such a position of the table, the coupling pin (9) is in its top dead center, supported by the plugs (14) inserted into the first horizontal section (13a) of the notches (13).

The clockwise rotation of the top (1 ) indirectly determines the rotation in the same direction of the platform (8) with consequent progressive extraction of the leaves (2) under the thrust of the connecting rods (12).

Evidently, the extraction travels of the leaves (2) are guided by the tracks (5) coupled with the slides (6 and 6'), and the rotation of the platform (8) is guided by the coupling pin (9) that exactly rotates inside the collar (10).

When the leaves (2) have completed a mutual separating travel sufficient to bring the concave side (2a) outside the border of the top (1 ), the latter will start the lowering travel imposed by the coupling between the plugs (14) and the second descending section (13b) of the notch (1 3); during said descending travel of the platform (8), the opposite pair of arms (8b and 8d) slide and are supported on the sloping profile (1 1 a) of the cams (1 1 ), whereas the other opposite pair of arms (8a and 8c) slide and are supported on the collar (10).

After a rotation of the top (1 ) by an angle equal to 180° minus (a), the leaves (2) have completed their maximum extraction travel that corresponds to the alignment of said opposite pair of arms (8a and 8c) with said axis of symmetry (X), as shown in fig. 5B;

In maximum extension configuration of the leaves (2), as shown in fig. 5B, the top (1 ) is at the end of the descending travel and perfectly leveled with the leaves (2), the concave side of which (2a) is separated by a small space (S) from the border of the circular top (1 ).

To recover and eliminate said space (S), the top (1 ) must be rotated by an angle (α') equal to angle (a).

Thus, the connecting rods (12) - which have been converted from arms into rods - are called back towards the center of the top (1 ) by said pair of arms (8a and 8c); during the latter angle of rotation (α') of the top (1 ), the plugs (14) slide into the third horizontal section (13c) of the notch (13), so that the top (1 ) maintains alignment with the leaves (12), the concave side of which (2a) is perfectly brought against the border of the top (1 ), after the latter has completed 180° rotation, as shown in fig. 5C.

Referring to the second set of figures 6 to 10C, a second embodiment of the table (T) of the invention is describes, which is basically identical, both in terms of structure and operation mode to the one describe and illustrated above, except for the configuration of said top-holding platform and for the configuration of the means adapted to determined the raising-lowering movement of the top (1 ).

It must be noted that, in such a second set of figures 6 to 10C, the same numeral are used to indicate the parts of the table that are common to both embodiments (T and T) of the table.

Referring to fig. 9, the table (T) comprises a support frame (30) under which said legs (4) are fixed, whereas two identical cross-pieces (5) are fixed on it on opposite sides, acting as support and guide tracks for two identical leaf- holding slides.

The top (1 ) is held and fixed on a platform (800) that is configured as hexagonal frame (80), comprising an opposite aligned pair of arms (80a and 80c) that respectively intersect two opposite vertices of said hexagonal frame (80).

Said opposite aligned pair of arms (80a and 80c) is fixed above a central pin (90) with vertical axis, inserted and rotating inside a collar (10), being an integral part of said frame (30).

In fact, said coupling pin (90) not only is free to rotate inside the collar (10) around a vertical axis (Y) passing through the center of the circular top (1 ), but also to make alternate vertical travels according to the same axis (Y), being guided by said collar (10).

A fixed disk (100) is situated between said platform (800) and said collar 810), which is anchored above said collar (10) and provided with a central hole (100a) for passage of said pin (90), which rotates both inside the collar (10) and the hole (100a) of the disk (100).

Said disk (100) comprises an opposite pair of cams (1 10) basically composed of an opposite pair of edges that extend for almost an arch of semicircle and are interrupted only for a short section (200).

In fact, each edge comprises two consecutive sections with different height: a first long section (1 10a) with constant height, and a second short section (1 10b) with wedge-shaped profile and decreasing height.

Said platform (800) is connected to the two slides (6,6') by means of two connecting-rods (120), each of them being pivoted at one end (120a) in the central point of the cross-pieces (6a, 6a'), whereas it is pivoted at the other end (12b) to the opposite aligned pair of arms (80a or 8c) of the platform (800), as shown in fig. 10C.

Said opposite aligned pair of arms (80a and 80c) protrudes from the opposite pair of cams (1 1 1 ) on which the same opposite aligned pair of arms (80a and 80c) lies and slides during the rotation of the platform (800) on which the top 81 ) is fixed. Referring to the set of figs. 10A, 10B and 10C, this description continues with the illustration of the automatic expulsion of the lateral leaves (2) when the top (1 ) is driven into rotation by an angle of 180° around the vertical axis (Y) passing through its center.

In particular, referring to fig. 10A, when the table (T) is not in extended position, the opposite aligned pair of arms (80a and 8c) forms an angle (a) with the axis of symmetry (X) of the crescent-shaped leaves (2).

In such a position of the table, the coupling pin (9) is at its top dead center, being supported by the opposite aligned pair of arms (80a and 80c) that lie on said first long section (1 10a).

The clockwise rotation of the top (1 ) indirectly determines the rotation in the same direction of the platform (800) with consequent progressive extraction of the leaves (2) under the thrust of the connecting rods (120).

Evidently, the extraction travels of the leaves (2) are guided by the tracks (5) coupled with the slides (6 and 6'), and the rotation of the platform (800) is guided by the coupling pin (90) that exactly rotates inside the collar (10).

When the leaves (2) have completed a mutual separation travel sufficient to bring the concave side (2a) outside the border of the top (1 ), the latter starts its descending travel imposed by the sloping profile of said second section (1 10b); in other words, during the descending travel of the platform (800), the opposite aligned pair of arms (80a and 80c) slide and are supported on the sloping profile (1 10b) of the cams (1 10), after which said opposite aligned pair of arms (80a and 80c) is exactly engaged in said section (200), as shown in fig. 8.

After a rotation of the top (1 ) by an angle equal to 180° minus (a), the leaves (2) have completed their maximum extraction travel that corresponds to the alignment of said opposite pair of arms (80a and 80c) with said axis of symmetry (X), as shown in fig. 10B.

In maximum extension configuration of the leaves (2), as shown in fig. 10B, the top (1 ) is at the end of the descending travel and perfectly leveled with the leaves (2), the concave side of which (2a) is separated by a small space (S) from the border of the circular top (1 ). To recover and eliminate said space (S), the top (1 ) must be rotated again by an angle (α') equal to angle (a).

Finally, attention is drawn on the diametrically opposite pair of catches (300) protruding from the internal part of the cams (1 10) and suitable to interfere - as stops for 180° rotation of the platform (800) - with an opposite aligned pair of arms (81 and 82), perpendicularly intersecting with the opposite aligned pair of arms (80a and 80c).

Said opposite aligned pair of arms (81 and 82) is preferably fixed under a rod (83) orthogonally fixed above the opposite aligned pair of arms (80a and 80c).