EP3466302B1

EP3466302B1 - A height-adjustable table

Info

Publication number: EP3466302B1
Application number: EP18197674.7A
Authority: EP
Inventors: Luciano Marchina
Original assignee: Mara SRL
Current assignee: Mara SRL
Priority date: 2017-10-06
Filing date: 2018-09-28
Publication date: 2020-04-15
Anticipated expiration: 2038-09-28
Also published as: EP3466302A1; ES2808980T3

Description

The present invention relates to a height adjustable table. More specifically, the present invention relates to a table whose top is adjustable in height as a function of the numerous requirements of a user, said table being suitable for use in houses, offices, and similar civil and commercial environments.
As is well known, a table typically comprises a table top and support elements for supporting said table top, which possibly comprises one or several legs having a height suitable for spacing the table top from the ground and allowing for a comfortable and ergonomic seat for a user. The mentioned tables are either fixed or adjustable in height in order to fit the different user's requirements or to take account of the user's height or even to make it possible for him/her to change his/her own posture if he/she is to stay seated at the table for a more or less long period of time over the day; as a matter of fact, some studies found that changing his/her own posture results in advantages for a person's comfort (in particular with reference to his/her back) and allows to improve concentration and consequently to improve productivity and efficiency.
Typically, height adjustable tables comprise telescopic support elements or uprights or table legs and their adjustment can be made by manually lifting the table top and locking the support elements or uprights by means of locking pins or dowels or other means suitable for this purpose.
Table height adjustment can also be made manually, for instance, by using a ring nut-toothed wheel device comprising a handle which controls a roto-translational movement which allows to lift the table top or to lower it depending on the actual requirements.
Another known way to adjust table height is a snap pedal one which drives a jack-type actuator or a telescopic mechanism complete with a manual locking element consisting of a pin insertable or screwable in the structure of the uprights of the table itself.
Other known solutions for adjusting tables in height comprise the use of spring- or gas pump-based actuators or electrical/motor-driven actuators.
However, such known mechanisms suitable for adjusting the top of a table in height entail a number of major drawbacks.
CN201550843U discloses a desktop elevator mechanism, which has driving gear meshed with driven gear, and motor installed at bottom part of desktop and including drive shaft for outputting power, where drive shaft runs through driving shaft.
A first drawback, which is typical of manual adjustment devices, is bound to the fact that a user shall, for instance, lift the table top manually and then insert or operate the elements used to block the support elements or uprights of the table in position, and such operation might be difficult (if performed by one person) in the case of big-size table tops (such as, for instance, tops of drawing boards or drafting machines) or table tops made from heavy materials.
A further drawback which is typical of spring- or gas-pump-based height adjustment mechanisms is bound to such mechanisms featuring a quick return that results in undesired impacts.
A further drawback which is conversely typical of electrical/motor-driven mechanisms is bound to the presence of electronic components and/or control units and consequently to the impossibility of adjusting the height of the table top in the event, for instance, of an electric power failure or the like.
A further drawback consists in that the gas pumps used for adjusting tables in height tend to run down and, consequently, make it difficult, or even impossible, to perform a height adjustment of tables over time and, also, they feature a non-variable load.
A further drawback is bound to the use of electric type actuators or, in any case, motor-driven devices to adjust the height of a table top in a motor-driven manner; as a matter of fact, such solutions are very susceptible of damages (impacts, external damages, etc.), are complex and expensive to maintain and/or to repair, and are also tendentially noisy.
An object of the present invention is to obviate the drawbacks listed above.
More specifically, an object of the present invention is to provide a table that is continuously adjustable in height, so as to allow for an optimum adjustment of the height of the table top with respect to the ground as a function of the specific user's requirements.
A further object of the present invention is to provide a table whose adjustment can be made by one person manually and effortlessly.
A further object of the present invention is to provide a table wherein the height adjustment of the table top is simple and can be made by a user effortlessly.
A further object of the present invention is to put at a users' disposal such height adjustable table as to guarantee long lifetime and reliability over time and also such as to be realized in an easy and cost-effective manner.
These objects and others are achieved by the invention that has the characteristics according to claim 1.
In accordance with the invention, a height adjustable table is provided whose top is adjustable as a function of a user's requirements, comprising a frame defining a support structure for a table top and comprising a pair of opposed and parallel feet defining an element whereby the frame rests on the ground or floor, at least one pair of opposed and parallel uprights rigidly secured to said feet and developing in a vertical direction, and a cross-member fixed to said pair of parallel and opposed uprights on an opposed side to the securing one with respect to the feet, every upright comprising a first tubular element and a second tubular element telescopically movable with respect to the first tubular element, a table that comprises mechanical cooperation means in the manual, telescopic lifting/lowering movement of the table while zeroing the associated weights.
Advantageous embodiments of the invention are apparent from the dependent claims.
The constructional and functional characteristics of the height adjustable table according to the present invention can be better understood from the following detailed description wherein reference is made to the attached drawings which represent a preferred, non-limitative embodiment thereof, and wherein:

figure 1 schematically shows a partially cross-sectioned front view of the height adjustable table in a condition wherein the table is completely lifted;
figure 2 schematically shows a top view of the height adjustable table according to the invention;
figure 3 schematically shows a cross-sectional view according to plane A-A in figure 1;
figure 4 schematically shows a partially cross-sectioned front view of the table according to the invention in a completely lowered configuration;
figure 5 schematically shows a cross-sectional view of the table according to the invention in accordance with vertical plane A-A in figure 4;
figure 6 schematically shows an axonometric, exploded view of the height adjustable table according to the invention;
figure 7 schematically shows a partially cross-sectioned side view of the height adjustable table according to the invention in accordance with an alternative embodiment and in a condition wherein the table is completely lowered;
figure 8 schematically shows a front view of the table depicted in figure 7 in a condition wherein the table is completely lowered;
figure 9 schematically shows a partial top view (the table top being removed) of the height adjustable table according to the alternative embodiment in a condition wherein the table is completely lowered;
figure 10 schematically shows a partially cross-sectioned side view of the height adjustable table according to the alternative embodiment in a condition wherein the table is completely lifted;
figure 11 schematically shows a magnified detailed view of a portion of the side section in accordance with figure 10. With reference to the mentioned figures and with a special reference to figure 6, the height adjustable table according to the present invention, identified by the reference numeral 10 as a whole, comprises a frame 12 defining a support structure for supporting a table top (not shown in the figure), said frame 12 comprising a pair of opposed and parallel feet 14 defining the element whereby the frame rests on the ground or floor, at least one pair of opposed and parallel uprights 16 rigidly fixed to said feet 14 and developing in a vertical direction, and a cross-member 20 secured to said pair of parallel and opposed uprights 16 on an opposed side to the securing one with respect to the feet 14.

Each of the uprights 16 comprises a first hollow tubular element 16' secured to the foot 14 and at least one second hollow tubular element 16" put on said first tubular element 16' and translatorily movable with respect thereto so as to make up a telescopic mechanism, as better detailed below; in the preferred embodiment depicted in the figures, every upright comprises a first tubular element and a second tubular element coaxially put on the first tubular element and translatorily movable with respect thereto, however it is understood that a further tubular element might be arranged coaxially to the second tubular element and be slidable with respect to the latter, as a function, for instance, of the maximum lifting height to be achieved for the table or, alternatively, as a function of aesthetic canons or of the components to be inserted in said uprights.
In the preferred embodiment depicted in figures 1 thru 6, the tubular elements 16' and 16" which define the uprights 16 feature a substantially quadrangular cross-section, however they might also feature a circular or polygonal cross-section, as a function of any aesthetic canons or appearances.
In particular, the first tubular element 16' has cross-sectional dimensions smaller than those of the second tubular element 16" which is put on said first tubular element.
A truck 18 is secured to an outer side surface of the first tubular element 16', at an upper end opposed to the lower end connecting to a single foot 14, suitable for slidingly coupling (in order to perform a function as described below) with a rail 19 featuring a longitudinal development substantially corresponding to the longitudinal development of the second tubular element 16" and secured to the second tubular element 16" in correspondence with an inner side surface which faces the outer side surface of the first tubular element 16' to which said truck 18 is secured.
Internally to the second tubular element 16" there is secured a U-shaped open tubular element 24 featuring a longitudinal development substantially corresponding to that of the second tubular element 16'', on which there is arranged a transmission 26 comprising a chain 27 extending from a first pulley 28 rotatably arranged at a lower end of the U-shaped tubular element 24 facing the foot 14 and a second pulley 29 rotatably arranged at an opposed end of the same U-shaped tubular element 24; said U-shaped tubular element 24, as better detailed below, defines a further truck for translatorily moving the second tubular element 16" with respect to the first tubular element 16'.
The chain 27 of the transmission 26 is constrained to the first tubular element 16' by means of a locking element 21 which defines a constraint for a link of the chain 27 with respect to the truck 18 in such a way that the translatory movement subsequently described for lifting/lowering the table turns in a rotational movement of the pinions that subtend the chain 27 synchronically; said locking element 21 is secured to the first tubular element and to a link of the chain and, in particular and preferably, said locking element 21 is constrained to the first tubular element 16', the center-to-center distances being the same as those of the truck 18.
An elastic element 30, comprising an Archimedean spiral spring, is secured internally to the U-shaped tubular element 24 and is wound about a rotation pin 32 rotatably secured to the U-shaped tubular element 24 below the first pulley 28 of the transmission 26; in particular, the elastic element 30, being a spiral spring, is anchored to said rotation pin 32 at one end thereof and to the first tubular element 16' at its opposed end.
A plate 36 is provided to close the upper end of the second tubular element 16" and defines a securing means for securing a table top stabilized to the frame or support structure 12.
The cross-member 20 comprises a further U-shaped tubular element, internally to which there is arranged a shaft 38, preferably but not exclusively featuring a hexagonal cross-section, for implementing a form coupling with the second pulley 29 of the transmission 26.
A bevel gear pair transmission 40 is arranged internally to the further U-shaped tubular element 20 (preferably at the middle of its longitudinal development) and comprises a first bevel gear 40' coaxially put in the shaft 38 and a second bevel gear 40" whose axis of rotation is perpendicular to that of said shaft and meshes the first bevel gear (the second bevel gear 40" is an idle rotation one) .
A pair of opposed torsion springs, comprising a first torsion spring 42 and a second torsion spring 44, are put on the shaft 38 and arranged externally to the bevel gear 40, opposed and coaxial to each other.
The first torsion spring 42 is secured to a block 45 put on the shaft 38 at one end and to the first bevel gear 40' at the opposed end.
The second torsion spring 44 is secured to the shaft 38 at one end (that facing the bevel gear pair 40) and to a further block 46 put on the shaft 38 and facing the block 45 at the opposed end.
The operation, and more specifically the lifting and lowering movement of the height adjustable table according to the present invention as described above in details with reference to its constructional characteristics, is described below.
Figures 4 and 5 show the configuration of a completely lowered table, the second tubular element 16" of the frame 16 being completely superimposed to the first tubular element 16'; in such configuration, the elastic element 30, comprising an Archimedean spiral spring, is unwound, considering the fact that it is secured to an upper end (opposed to the feet 14) of the first tubular element 16' at one end thereof.
Figures 1 thru 3 show the configuration of a completely lifted table, i.e. a table wherein the second tubular element 16" is shifted in height with respect to the first tubular element 16' and completely extended with respect thereto, the lower end portion of said second tubular element 16" being in correspondence with the upper end portion of the first tubular element 16'.
In this configuration, the elastic element 30, comprising an Archimedean spiral spring, is substantially completely wound about the rotation pin 32.
The lifting/lowering movement of the table is a telescopic one, the second tubular element 16'' performing a translatory movement with respect to the first tubular element 16' which is fixed with respect to the feet 14 on which the table rests on the ground.
During the lifting/lowering movement the shaft 38, being connected to the transmission 26, rotates and drives the bevel gear pair 40 into rotation and, consequently, operates the torsion springs 42 and 44 which load/unload depending on whether the elastic element comprising the Archimedean spiral spring winds or unwinds; in this way, the bevel gear pair 40 operates as a pre-load for the torsion springs 42 and 44 which cooperate with the elastic element 30 comprising the Archimedean spiral spring by acting on the horizontal rotational movement of the shaft 38, which is integral with the vertical elastic movement of the second tubular element 16".
During the lifting/lowering step, the elastic element comprising the Archimedean spiral spring follows the movement so as to zero the weights and consequently makes the movement easier.
With reference to figures 7 thru 11, they show a table according to the invention in accordance with an alternative embodiment.
With reference to the mentioned figures (the details common to the preferred embodiment described above will not be described here in details), the height adjustable table according to the present invention, identified by the reference numeral 10' as a whole, comprises a frame 50 which defines a structure for a table top stabilized with respect to the rest elements 52, the frame 50 comprising a pair of opposed and parallel rest feet 44, at least one pair of opposed and parallel uprights 56 rigidly secured to said feet 54 at one end, and a cross-member 58 secured to said pair of parallel and opposed uprights 56 on an opposed side to the securing side with respect to the feet 54.
Each of the uprights 56 comprises a first hollow tubular element 56' secured to the foot 54 and at least one second hollow tubular element 56" arranged internally to said first tubular element 16' and translatorily movable with respect thereto to make up a telescopic mechanism for lifting the table top.
In the preferred embodiment according to the figures, the tubular elements 56' and 56" which make up the uprights 56 feature a substantially quadrangular cross-section, however they might also have a circular or polygonal cross-section, depending on aesthetic canons or appearances, if any.
In particular, the cross-section of the first tubular element 56' has greater dimensions than those of the second tubular element 56" which is arranged internally to said first tubular element.
Internally to the first tubular element 56', in correspondence with an inner side surface that faces an outer side surface of the second tubular element 56", there is secured a rail 60 having a longitudinal development substantially corresponding to the longitudinal development of the first tubular element 56'.
A truck 62 suitable for slidingly coupling with the rail 60 is secured externally to the second tubular element 56" and on an outer side surface, in correspondence with a lower end of said second tubular element facing a lower end of the first tubular element 56' connecting to a single foot 54.
A transmission 64 comprising a chain 66 running from a first pulley 68 rotatably arranged at a lower end of the second tubular element 56" facing the foot 54 to a second pulley 70 rotatably arranged at an opposed end of the same second tubular element is arranged internally to the second tubular element 56".
The chain 66 is constrained to the first tubular element 56' by means of a locking element 72 which defines a constraint for a link of the chain 66 with respect to the rail 60, so that the translatory movement for lifting/lowering the table results in a rotational movement of the pinions that subtend the chain 66 synchronically; the locking element 72 is secured internally to the first tubular element 56' and longitudinally engages a slot 74 formed on the second tubular element 56" and, also, it comprises a pin 76 suitable for engaging a link of the chain 66 for locking the lifting/lowering position of the table.
An elastic element 78, comprising an Archimedean spiral spring, is secured internally to the second tubular element 56" and is wound about the first pulley 68; in particular, the elastic element 78, being a spiral spring, is anchored to the first pulley 68 at one end and to the first tubular element 56' at an opposed end 78'.
The cross-member 58 comprises a further tubular element internally to which there is arranged a shaft 80, for coupling the second pulley 70, in order to allow for a synchronization of the lifting/lowering movement between said pair of uprights 56.
The operation of the height adjustable table according to the present invention is described below.
Figure 7 shows the configuration of a fully lowered table, wherein the second tubular element 56" is completely accommodated within the first tubular element 56'; in such configuration the elastic element 78 is unwound, considering the fact that it is secured to an upper end of the first tubular element 56' at one end 78'.
Figure 10 shows the configuration of a completely lifted table, wherein the second tubular element 56" is completely extended with respect to the first tubular element 56', the lower end portion of said second tubular element 56" being in correspondence with the upper end portion of the first tubular element 56'.
In this configuration the elastic element 78 is substantially completely wound about the first pulley 68. During the telescopic lifting/lowering movement the shaft 80, being connected to the transmission 64, rotates and determines a synchronization in the translatory movement of the second tubular element 56" of every upright 56. During the lifting/lowering step the elastic element 78 follows the movement of the second tubular elements 56" thus zeroing the weights and, consequently, makes the movement easier.
The advantages achievable by using a height adjustable table according to the present invention are apparent from the foregoing.
The height adjustable table according to the present invention makes it possible a continuous adjustment of the table height so as to allow for an optimum adjustment of the height of the table top with respect to the ground as a function of the specific user's requirements.
A further advantage is in that the table according to the invention makes it possible a manual effortless adjustment, thanks to the presence of an Archimedean spiral spring which, having a flat behavior, does not have any stress peaks and follows the lifting/lowering movement thus zeroing the weights and substantially simulates an almost complete absence of weight.
A further advantage consists in that, thanks to the presence of a bevel gear pair, the height adjustable table according to the present invention makes it possible to have a variable load (thanks to the springs being loaded with the bevel gear pair itself).
A further advantage of the height adjustable table according to the invention consists in that the height adjustable table in accordance with the described modes is found to be very silent during the lifting/lowering steps. Even though the invention has been described above with a special reference to an embodiment thereof given for explanatory non-limitative purposes only, numerous modifications and variants will be apparent to those skilled in the art in the light of the above description. Therefore, the present invention shall be construed to embrace any modifications and variants that fall in the scope of the following claims.

Claims

A height adjustable table (10, 10') wherein the table top is adjustable as a function of a user's requirements, comprising a frame (12, 50) defining a support structure for a table top, a pair of opposed and parallel feet (14, 54) defining the frame rest element (12, 50) for making the frame rest on the ground or floor, at least one pair of opposed and parallel uprights (16, 56) rigidly secured to said feet (14, 54) and developing in a vertical direction, and a cross-member (20, 58) secured to said pair of parallel and opposed uprights (16, 56) on an opposed side to the securing side with respect to the feet (14, 54), every upright (16, 56) comprising a first tubular element (16', 56') and a second tubular element (16", 56") translatorily movable according to a telescopic movement with respect to the first tubular element, characterized in that it comprises mechanical means for cooperating in the manual lifting/lowering movement of the table, which comprise a transmission (26, 64) comprising a chain (27, 66) running from a first pulley (28, 68) rotatably arranged at a lower end of the second tubular element (16", 56") facing the foot (14, 54) to a second pulley (29, 70) rotatably arranged at an opposed end of the same second tubular element (16", 56"), an elastic element (30, 78) arranged internally to the second tubular element (16", 56") and comprising an Archimedean spiral spring cooperating with the transmission (26, 64), said mechanical means cooperating in the lifting/lowering movement also comprising means for synchronizing the lifting/lowering movement between said pair of uprights (16, 56) arranged internally to the cross-member (20, 58).
The adjustable table according to claim 1, characterized in that the first tubular element (16', 56') and the second tubular element (16'', 56") of every upright (16, 56) are hollow and are arranged coaxially to each other, the second tubular element (16", 56") being put on the first tubular element (16', 56') being secured to the ground rest feet (14, 54) at one end.
The adjustable table according to claim 1 or 2, characterized in that internally to every upright (16, 56) there is secured a truck (18, 62) suitable for slidingly coupling with a rail (19, 60) also arranged internally to every upright (16, 56).
The adjustable table (10) according to claim 3, characterized in that the truck (18) is secured to an outer side surface of the first tubular element (16'), at an upper end opposed to the lower end connecting to each individual foot (14), and the rail (19) is secured to the second tubular element (16") in correspondence with an inner side surface which faces the outer side surface of the first tubular element (16') to which the truck (18) is secured and has a longitudinal development substantially corresponding to the longitudinal development of the second tubular element (16'').
The adjustable table (10') according to claim 3, characterized in that the truck (62) is secured externally to the second tubular element (56") on an outer side surface thereof in correspondence with a lower end of said second tubular element (56") facing a lower end of the first tubular element (56') connecting to each individual foot (54), the rail (60) being secured to an inner side surface of the first tubular element (56') which faces an outer side surface of the second tubular element (56"), said rail (60) having a longitudinal development substantially corresponding to the longitudinal development of the first tubular element (56').
The adjustable table (10) according to any of claims 1 thru 4, characterized in that the second tubular element (16") comprises a U-shaped open tubular element (24) secured to said second tubular element having a longitudinal development substantially corresponding to that of the second tubular element (16"), a transmission (26) being arranged internally to said U-shaped open tubular element (24), the first pulley (28) being rotatably arranged at a lower end of the U-shaped tubular element (24) facing the foot (14) and the second pulley (29) being rotatably arranged at an opposed end of the same U-shaped tubular element (24).
The adjustable table (10) according to claim 6, characterized in that the Archimedean spiral spring defining the elastic element (30) is arranged internally to the U-shaped tubular element (24) and is wound about a rotation pin (32) rotatably secured to the U-shaped tubular element (24) below the first pulley (28) of the transmission (26), the elastic element (30) being anchored to said rotation pin (32) at one end thereof and to the first tubular element (16') on the opposed end, on an inner surface in correspondence with the end portion opposed to the end portion secured to the foot (14).
The adjustable table (10') according to claim 1, characterized in that the Archimedean spiral spring defining the elastic element (78) is wound about the first pulley (68) of the transmission (74), one end being secured to said first pulley (68) and the opposed end (78') being secured to the first tubular element (56').
The adjustable table according to one or several of the previous claims, characterized in that the chain (27, 66) of the transmission (26, 64) is constrained to the first tubular element (16', 56') by means of a locking element (21, 72) defining a constraint for a link of the chain (27, 66) with respect to said first tubular element (16', 56') for transforming a translatory lifting/lowering movement of the second tubular element (16", 56") with respect to the first tubular element (16', 56') into a rotational movement of the means used to synchronize the lifting/lowering movement between said pair of uprights (16, 56) arranged internally to the cross-member (20, 58), said locking element (21, 72) being secured to the first tubular element (16', 56') and being suitable for engaging a link of the chain (27, 66).
The adjustable table according to one or several of the previous claims, characterized in that the cross-member (20, 58) accommodates a shaft (38, 80) internally thereto for allowing a coupling between the second pulleys (29, 70) of the transmission (26, 64) of the pair of second tubular elements (16'', 56") of the uprights (16, 56) for a synchronization of the lifting/lowering movement between said pair of uprights (16, 56).
The adjustable table according to claim 10, characterized in that the cross-member (20) comprises a bevel gear pair (40) based transmission arranged substantially at the middle of its longitudinal development of the shaft (38) and comprises a first bevel gear (40') coaxial to the shaft (38) and a second bevel gear (40") having an axis of rotation perpendicular to that of said shaft (38) and meshes said first bevel gear (40').
The adjustable table according to claim 11, characterized in that it comprises a pair of opposed torsion springs, comprising a first torsion spring (42) and a second torsion spring (44) put on the shaft (38), externally to the bevel gear pair (40) and opposed and coaxial to each other.
The adjustable table according to claims 11 and 12, characterized in that the first torsion spring (42) is secured to a block (45) put on the shaft (38) at one end and to the first bevel gear (40') of the bevel gear pair (40) at the opposed end, the second torsion spring (44) being secured to the shaft (38) at one end, facing the bevel gear pair (40), and to a further block (46) put on the shaft (38) and opposed to the block (45) at the opposed end.