Technical field of the invention
[0001] The present invention relates to the technical field of folding tables. It relates
more specifically to a folding table of the type that comprises a table top consisting
of two halves that are articulated to one another, it being possible for the two halves
to be either extended to form a single plane or folded against one another, and a
frame underneath the table top to support the table at the right height from the floor.
The present invention is particularly applicable for a folding table of the aforementioned
type that is adapted for use as a table tennis or ping-pong table.
Background of the invention
[0002] As is well known, some ping-pong tables offer the possibility of being folded along
the middle, in such a way that each of the halves is in vertical position, one adjacent
to the other. This means that once play has finished, the space occupied by the table
is reduced as much as possible so that it can be occupied by other items or for a
different activity. Except in permanent competition or merely recreational facilities,
it is advisable for tables to be foldable and light, in order to enable their easy
removal and leave the occupied space free.
[0003] Therefore, the aim is to achieve a ping-pong table that is easily foldable, which,
once folded, occupies the smallest possible space, is light yet robust and has a simple
folding mechanism that is safe and efficient (in order to reduce production costs).
Normally, the simultaneous application of all these factors creates conflicts wherein
the manufacturer is forced to optimise one or more of said characteristics to the
detriment of the rest. For example, in theory, a simple folding mechanism could be
associated with a mechanism that is not very robust or low-quality.
[0004] There are currently several types of folding tables in the prior art. These include
utility model
ES256416U, which claims an underneath frame that is very large and is not foldable. The foldable
part that is claimed for this table is the table top.
[0005] Another Spanish utility model, with publication number
ES1007292U, discloses a folding ping-pong table wherein the legs are removed from the table
top when this is to be folded.
[0006] In general, it is desirable for all the pieces or elements that form part of the
table during its operational state to be attached thereto when it is stored or transported.
[0007] The utility model with application number
ES0208534U discloses a folding ping-pong table wherein the structures of the legs fold inwards
by means of telescopic arms. This type of mechanism, which is well known in different
industrial sectors, involves a certain degree of complexity in its manufacture and
is not sufficiently robust, especially when the table must be folded and unfolded
frequently.
[0008] The present invention presents an alternative mechanism that is applied to ping-pong
tables so that they may be folded quickly and easily. At the same time, said mechanism
is simple to manufacture and the result is a folding ping-pong table that, once folded,
occupies very little space and is easy to store and transport.
Explanation of the invention
[0009] For this purpose, the object of this invention is a folding table of the aforementioned
type, which is essentially characterised in that
the two halves are articulated to one another on hinges situated in the area where
the two halves of the table top join one another;
and in that
the frame comprises at least two support assemblies that are symmetrical with regard
to the imaginary plane that is perpendicular to the plane of the extended table top
which passes through the axis of the articulation of the two halves of the table top,
each support assembly having at least two legs articulated at the top to the corresponding
half of the table top, and at least one strut connected by articulation at one end
to one of the legs and by the other end to the other half of the table top, also by
articulation, at a certain distance from the articulation of the two halves of the
table top, in such a way that, in each support assembly, the leg, the strut, the segment
of one half that is between a first articulation and a third articulation, and the
segment of the other half that is between a second articulation and a third articulation
form an articulated quadrilateral structure. This allows the table to be folded by
lowering the opposite ends of the two halves.
[0010] According to another feature of this invention, in each support assembly the lengths
of their elements are such that they substantially verify the relationship wherein
the sum of the lengths of the strut plus the section of the table top that runs from
the articulation of the two halves of the table top to the point of articulation of
the strut with the table top is equal to the sum of the lengths of the segment that
runs from the point where the strut is attached to the leg to the articulated top
end of said leg plus the segment that runs from said articulated top end of the leg
to the articulation of the two halves of the table top.
[0011] According to another feature of the present invention, the shaft of the hinges is
situated, in the table's unfolded position, below the level of the plane formed by
the two unfolded halves, and on the vertical plane defined by the adjacent edges of
the two halves of the table, the two halves thus being positioned in parallel, in
the table's folded position, for transport or storage.
[0012] Preferably, the two halves are positioned at a distance of less than 110 mm from
one another in the table's folded position.
[0013] According to another feature of the present invention, each support assembly comprises
a strengthening crossbar that joins at least two of the legs of said assembly.
[0014] According to another feature of the present invention, at least one strut is connected
by articulation by one end to the corresponding crossbar and by the other end, also
by articulation, to the other half of the table top, at a certain distance from the
articulation of the two halves.
[0015] According to yet another feature of the present invention, the legs comprise corresponding
wheels on the end that rests on the floor.
[0016] In the case of a ping-pong table that simply has said attributes, these might not
be sufficient to pass the European Standard in preparation regarding table tennis
tables, which will require the table to withstand forces of more than 80 kg.
[0017] Another feature of this invention is that the table comprises central support legs
at each end of the articulation, which work with the legs to support the table on
the floor and receive support from the articulation of the rotating shaft of the hinges
and the table. Preferably, the support legs will stand slightly outside the perimeter
of the table top area.
[0018] This feature helps to provide a very robust ping-pong table, which means that it
can easily withstand said minimum of 80 kg.
[0019] According to another feature of the present invention each central support leg has
a safety system that comprises a bushing which slides with friction along a vertical
bar of said central leg, each bushing having at least two support arms that are secured
by one end to the bushing by articulation, and secured by the other end, by articulation
and so that they may slide, to the underside of a respective half of the table top.
[0020] This safety system works in a similar way to the spoke structure of an umbrella and
provides friction between the bushing and the vertical bar of the central leg, thus
preventing the sudden fall of the folded or half-folded table. A system whereby the
bushings lock onto the bar of the leg can secure the table in a folded position, it
thus having both active and passive safety systems.
[0021] According to another feature of the present invention, the table comprises a vertical
net along the axis of articulation of the two halves of the table top in such a way
that both the net and the table have dimensions and a shape that are suitable for
playing table tennis or ping-pong.
[0022] Another additional feature of the present invention is that the vertical posts that
hold up the net are attached to the tops of the central support legs.
[0023] Another feature of this invention is that the vertical posts may be detached from
the tops of the central support legs.
[0024] The vertical posts are preferably able to regulate the height and separating distance,
in order to modify the tension of the net.
[0025] Another feature of the present invention is that the folding table comprises two
T-shaped connection pieces, with three connection points respectively for the corresponding
end of the central hinge assembly, the base of the corresponding vertical post of
the net and the top of the corresponding central support leg, the shape of said connection
pieces being graded from a substantially circular cross-section to a substantially
oval cross-section in correspondence with the respective cross-sections of the central
support legs and of the central hinge assembly.
[0026] The support arm of each of the wheels swivels at the point where it is joined to
each of the respective legs in such a way that said wheels have at least three fixed
positions in relation to the position of play: 0°, 90° and 180°.
[0027] Persons skilled in the art will appreciate that the new and inventive features of
this invention, in addition to providing an overall effective solution to the aforementioned
disadvantages, make it possible to manufacture a folding ping-pong table with a folding
mechanism that is solidly joined to the structure of the table and is at the same
time simple and robust, with the consequent advantages from the production point of
view. Furthermore, the space occupied by the table in its folded state is minimal
as the two halves of the table top are positioned against one another.
[0028] Moreover, the modular structure and functionality of the parts of the table according
to this invention mean that it is possible to manufacture these entirely from plastic,
with the consequent advantage that the joints may be achieved by riveting, which is
a very fast, economical and safe procedure. The table can be manufactured in subsets
and/or modules, which facilitates logistics and can simplify the production process
in batches.
Brief description of the drawings
[0029] In the attached drawings embodiments of the folding ping-pong table that is the object
of the invention are illustrated by means of a non-limiting example. In said drawings:
- Fig. 1
- is a plan view of the folding ping-pong table of this invention;
- Fig. 2
- is a front view of the ping-pong table of this invention when folded;
- Fig. 3
- is a side view of the ping-pong table according to this invention in an intermediate
state between the extension of the table top and the folded state thereof;
- Fig. 4
- is a side view of the ping-pong table of this invention when completely folded;
- Fig. 4b
- is a side view of the ping-pong table without the covers of the central support legs;
- Fig. 5
- is a side view of the ping-pong table of this invention when completely un folded;
- Fig. 6
- is a perspective view of the underneath of the table of this invention;
- Fig. 7
- is a longitudinal cross-section of the folding table of this invention;
- Figs. 8, 9 and 10
- are details of the folding system by friction with the bushing, as shown in Fig. 7,
in a completely unfolded position, a halffolded position and a completely folded position
of the table respectively; and
- Fig. 11
- is an exploded view of the central hinge assembly, the central support legs and the
T-shaped connection pieces of the table of this invention.
Detailed description of the drawings
[0030] Said drawings show a preferred embodiment of this invention, which is applicable
to a ping-pong or table tennis table.
[0031] Fig. 1 shows a plan view of the ping-pong table 1 unfolded as for play. Obviously,
this state is irrelevant in terms of the advantages provided by this invention as
the standard measurements of the table top determine the space that the whole table
must obligatorily occupy and the aforementioned figure is shown for illustrative purposes.
[0032] The folding table 1 comprises a table top consisting of two halves 2; 2', which are
articulated on two hinges 18, one on either side of the table 1, that are particularly
visible in Fig. 6. The halves 2, 2' can be extended to form a single plane or positioned
adjacent to one another in parallel for transport or storage purposes, and there is
a frame underneath the table top to support the table on the ground at the right height.
[0033] In order to aid comprehension of the folding mechanism that will be described below,
the numerical references designate equivalent and symmetrical elements in both halves
of the structure of the table 1, although they are differentiated by the symbol (').
For example, said figure shows that the two halves 2, 2' of the table 1 adopt the
same reference (2), the only difference being the one just stated above.
[0034] The folding mechanism, situated underneath the table 1, can be best seen in Fig.
3. Said folding mechanism also acts as the frame that supports the table 1. It essentially
consists of two articulated quadrilateral structures that are known in other industrial
and mechanics sectors. Each half 2, 2' of the table 1 has a corresponding articulated
quadrangle. For example, in the case of half 2, the quadrangle consists of the leg
5 or 6, the strut 7, segment CD (C being the point of articulation of said strut 7
in relation to the opposite half 2' of the table top) and segment AD (A being the
point of articulation of the leg 5 or 6 in relation to the corresponding half 2 of
the table top). One of the segments has been defined as the leg 5 or 6 due to the
fact that the strut 7 can be attached to the end of either of the two legs 5, 6, or,
as will be seen later, it can be attached to a strengthening crossbar 9 (optional
though preferred) that joins the two legs 5, 6; it is also possible for the table
1 to have a greater number of struts 7 depending on the desired mechanical resistance
for the materials with which the table 1 is made in each case. All these elements
can be seen more clearly in Fig. 6 which shows the underside of the table 1.
[0035] The same articulated quadrilateral structure is symmetrically repeated for the other
half 2' of the table 1. The four vertices A, B, C, D (or A', B', C', D where this
is the case) of the quadrangle are points of articulation of the corresponding segments
that form the sides thereof so that the structure can be folded, the sides of the
quadrangle thus being positioned adjacently in pairs. In order to achieve an optimum
folding of the table 1, that is, a folded state that occupies the smallest possible
space so that the two halves 2, 2' are substantially parallel and folded against one
another, the following situation must be achieved: BC + CD = BA + AD for one quadrangle,
and B'C' + C'D = B'A' + A'D for the other. This guarantees that it is possible to
achieve the situation in which the vertices BAD and BCD substantially form 180° and
segments AD and BA, and BC and CD, respectively, substantially form two straight lines.
The same situation can be extrapolated for the quadrangle of the other half 2' of
the table 1 by exchanging A, B and C for A', B' and C', respectively.
[0036] Points C and C' correspond to the articulations of the struts 7, 7', 8 and 8' on
the hinges 18 of the two halves 2 and 2'.
[0037] In Figs. 6 and 7 it can be observed that the shaft 19 of the hinges 18 is situated,
in the table's unfolded position, below the level of the plane formed by the two unfolded
halves 2, 2', and on the vertical plane defined by the adjacent edges of the two halves
of the table 1. This means that when the table 1 is folded, the two halves 2, 2',
in the folded position of the table 1, (Fig. 4), are positioned adjacent to one another
in parallel for transport or storage, thus occupying a smaller space, so that there
is a gap of less than 110 mm between the table tops, as specified by European Standards,
in order to prevent the entry of adults and children (Fig. 4b). This is possible thanks
to the movement of the shaft 19 of the hinges 18, which allows the adjacent edges
of the two halves to move away from one another as they rotate, which was not possible
with tables in the prior art.
[0038] Fig. 4, is a side view of the table 1 shown in Fig. 3 in a completely unfolded position.
As can be seen in said figure and more specifically in Fig. 4b (where the covers of
the central legs 12, 12' have been omitted for the sake of greater clarity) the space
occupied by the table 1 is reduced as much as possible, enabling it to be stored in
any free area of a house or, for example, sports facilities. Furthermore, the angled
structure of the bases of the legs 5, 5', 6, 6' helps provide the table 1 with sufficient
stability to transport it easily to the desired place. It can be observed that the
total thickness of the folded table 1 is only a little greater that that of the sum
of the two halves 2, 2' of the table top. Fig. 5 shows the table 1 completely unfolded
and in said figure the double articulated quadrilateral structure of vertices A, B,
C and D, and A', B', C' and D, respectively, can be more clearly observed. The eight
vertices of the two quadrangles are articulated, which, together with the aforementioned
situations BC + CD = BA + AD and B'C' + C'D = B'A' + A'D, enables one half 2 of the
table top to be practically folded flat in parallel to the other half 2'.
[0039] The materials from which the quadrilateral structure or frame of the table 1 is made
are not essential for the purpose of the invention, although it is desirable to use
lightweight materials in order to facilitate transport of the table 1 and it is essential
to achieve an economical and easy assembly of the table 1. Also, the connection or
shape of the elements that make up the articulated quadrangles of said frame are not
essential either. The fundamental aspect is the existence of two complementary articulated
quadrilateral structures that, with the geometrical form established above, allow
the table 1 to be folded completely.
[0040] Another aspect to be taken into account in tables 1 of this type is the ability to
move or transport them with the greatest possible ease. For this reason, the table
1 has a set of wheels 10, 10', 11, 11' positioned accordingly on the lower ends of
the legs 5, 5', 6, 6'. Once the table 1 is completely folded, it can be move more
easily and occupies less space.
[0041] The preferred embodiment of the invention also includes two central support legs
12, 12' which improve the stability of the table 1 when in its unfolded operation
state. These central legs 12, 12' are connected by a crossbar that forms the shaft
19 of the hinges 18, and they can be as robust as necessary according to the additional
stability desired for the table and depending on the materials used in each case.
[0042] The central legs 12, 12' receive support from the articulation of the bar of the
rotating shaft 19 of the hinges 18 and, consequently, the rotation that folds / unfolds
the table.
[0043] The central legs 12, 12' may also form a decorative and therefore commercially attractive
element for the sides of the table 1, especially when it is folded, said legs 12,
12' hiding the sight of the underneath of the table 1. Furthermore, in one of the
preferred embodiments of the invention, the tops of the central legs 12, 12' can act
as support for the posts 13, 13' that hold up the net 3 and in another alternative
of the invention, said posts 13, 13' can be detached from said legs 12, 12'.
[0044] The vertical posts 13; 13' can regulate the height and separating distance, in order
to modify the tension of the net, by means of a retaining mechanism 21 and 22 (Fig.
11).
[0045] The posts 13 and 13' are also designed so as to act as a handle to aid the folding
or unfolding procedure of the table 1.
[0046] Another of the advantages of the table 1 of this invention is that the folding system
allows the table 1 to be folded in such a way that the playing surfaces face outwards.
This facility aids the folding procedure, whereby it is only necessary to apply a
pushing force, thanks to the wheels 10, 10', 11, 11' on the legs 5, 5', 6, 6', and
not a lifting or raising force to lift each half 2, 2' of the table 1.
[0047] Figs. 7 to 10 serve specifically to show the folding system by friction with the
bushing 14, 14'. Each of the legs 12, 12' has a bushing 14, 14' connected by friction
to a respective vertical bar 20 of each leg 12, 12', along the outside whereof it
can slide. This bushing 14, 14' can slide along each leg 12, 12' so as to aid the
folding and unfolding of the table 1, as these movements are made more smooth thanks
to the friction of the corresponding bushing 14, 14' with the leg 12, 12' on which
it is mounted, and thanks to a pair of respective support arms 15, 16, 15', 16' that
join each bushing 14, 14' by articulation with the two halves 2, 2' of the table top.
Each bushing 14, 14' also has an inner bushing 23, 23'. Furthermore, the arms 15,
16, 15', 16' can slide, by the end fixed to the table 1 by articulation, along the
underneath of said table 1. Said bushing 14, 14' and support arm 15, 16, 15', 16'
assembly can be seen in an ordered exploded view in Fig. 11. Figures 8 to 11 also
show a Z-shaped safety lever 24, which is actuated by a spring and which is blocked
in the corresponding safety position by means of a catch. Said safety position prevents
the accidental opening of the table 1 in order to avoid possible accidents or injury
to the user.
[0048] In the folded position of the table 1, the bushings 14, 14' are in their lower position
(Fig. 10), in which they are blocked by the corresponding locking systems to the bars
20.
[0049] The support arm of each of the wheels 10, 11; 10', 11' swivels at the point where
it is joined to each of the respective legs 5,6; 5', 6' and comprises a mechanism
for fixing the angular position of the wheel in at least three fixed positions in
relation to the position of play: 0° (normal playing position), 90° (packaging and
transport position) and 180° (playing position for disabled people in wheel chairs).
This fixing mechanism may consist of locking systems in fixed positions of rotation
of the conventional type.
[0050] It should also be mentioned that, although this description has been drawn up on
the basis of a ping-pong table 1, said description is not limitative and all the characteristics
applicable to folding tables in general (such as the folding system using articulated
quadrangles) are protected by the attached claims as can be assumed from these. For
example, the folding table could be used to support blackboards or audiovisual projection
screens in meeting rooms or classrooms. This feature is very useful, for example,
in schools, colleges and educational establishments in general, in which the combination
of purely academic activities and leisure or sports activities is usual.
[0051] Having sufficiently described the nature of the present invention and the way in
which it is put into practice, it is stated that anything that does not alter, change
or modify its fundamental principle is subject to variations regarding details.
1. Folding table (1), which comprises a table top consisting of two halves (2, 2') that
are articulated to one another that can be either extended to form a single plane
or folded, and a frame underneath the table top adapted to support the table at the
right height from the floor,
characterised in that
the two halves are articulated to one another on hinges (18) situated in the area
where the two halves (2, 2') of the table top join one another;
and
in that
the frame comprises at least two support assemblies (4;4') that are symmetrical with
regard to the imaginary plane that is perpendicular to the plane of the extended table
which passes through the axis of the articulation of the two halves of the table top,
each support assembly having at least
- two legs (5, 6; 5', 6') joined by articulation at the top (A; A') to the corresponding
half of the table top, and
- at least one strut (7, 8; 7', 8') connected by articulation by one end (B; B') to
one of the legs and by the other end (C; C') to the other half of the table top, also
by articulation, at a certain distance from the articulation (D) of the two halves
(2; 2'),
in such a way that, in each support assembly, the leg (5), the strut (7), the segment
of one half (2) that is between the articulation (A) and the other articulation (D),
and the segment of the other half (2') that is between the articulation (C) and the
other articulation (D) form an articulated quadrilateral structure, which allows the
table to be folded by the opposite ends of the halves (2, 2').
2. Folding table (1) according to claim 1, characterised in that in each support assembly the lengths of its elements are such that they substantially
verify the BA + AD = BC + CD relationship.
3. Folding table (1) according to claims 1 or 2, characterised in that the shaft (19) of the hinges (18) is situated, in the table's unfolded position,
below the level of the plane formed by the two unfolded halves (2, 2'), and on the
vertical plane defined by the adjacent edges of the two halves of the table, the two
halves (2, 2') thus being positioned in parallel, in the folded position of the table
(1), for transport or storage.
4. Folding table (1) according to claim 3, characterised in that the two halves are positioned at a distance of less than 110 mm from one another
in the table's folded position.
5. Folding table (1) according to any of the previous claims, characterised in that each support assembly (4; 4') comprises a strengthening crossbar (9; 9') that joins
at least two of the legs (5, 6; 5', 6') of said assembly.
6. Folding table (1) according to claim 5, characterised in that at least one strut (7, 8; 7', 8') is connected by articulation by one end (B; B')
to the corresponding crossbar (9; 9') and by the other end (C; C') to the other half
of the table top, also by articulation, at a certain distance from the articulation
(D) of the two halves (2; 2').
7. Folding table (1) according to any of the previous claims, characterised in that the legs (5, 6; 5', 6') comprise corresponding wheels (10, 11; 10', 11') on the end
that rests on the floor.
8. Folding table (1) according to any of the previous claims, characterised in that it comprises central support legs (12, 12') at each end of the articulation (D),
which work with the legs (5, 6; 5', 6') to support the table on the floor and receive
support from the articulation of the rotating shaft (19) of the hinges (18) and the
table.
9. Folding table (1) according to any of the previous claims, characterised in that the articulations (C, C') are integrated into the hinges (18).
10. Folding table (1) according to any of the previous claims, characterised in that each central support leg (12, 12') has a safety system that comprises a bushing (14,
14') which slides with friction along a vertical bar (20) of said central leg, each
bushing (14, 14') having another respective bushing (23, 23') inside the other and
at least two support arms (15, 16; 15', 16') that are secured by one end by articulation
to the bushing, and secured by the other end, by articulation and so that they may
slide, to the underside of a respective half of the table top (2, 2').
11. Folding table (1) according to any of the previous claims, characterised in that it comprises a vertical net (3) along the axis of articulation of the two halves
of the table top in such a way that both the net and the table have dimensions and
a shape that are suitable for playing table tennis or ping-pong.
12. Folding table (1) according to claim 11, characterised in that the vertical posts (13; 13') that hold up the net (3) are attached to the tops of
the central support legs (12; 12').
13. Folding table (1) according to claim 12, characterised in that the vertical posts (13; 13') may be detached from the tops of the central support
legs (12; 12').
14. Folding table (1) according to any of claims 11 to 13, characterised in that the vertical posts (13; 13') are able to regulate the height and separating distance,
in order to modify the tension of the net.
15. Folding table (1) according to any of claims 11 to 14, characterised in that it comprises two T-shaped connection pieces (17, 17'), with three connection points
respectively for the corresponding end of the central hinge assembly (18), the base
of the corresponding vertical post (13, 13') of the net (3) and the top of the corresponding
central support leg (12, 12'), the shape of said connection pieces being graded from
a substantially circular cross-section to a substantially oval cross-section in correspondence
with the respective cross-sections of the central support legs and of the central
hinge assembly.
16. Folding table (1) according to any of claims 11 to 15, characterised in that the support arm of each of the wheels (10, 11; 10', 11') swivels at the point where
it is joined to each of the respective legs (5, 6; 5', 6') and comprises a mechanism
for fixing the angular position of the wheel in at least three fixed positions in
relation to the position of play: 0°, 90° and 180°.