WO2008127088A2

WO2008127088A2 - Device for height adjustment of a table top such as a working or writing desk

Info

Publication number: WO2008127088A2
Application number: PCT/NL2008/000101
Authority: WO
Inventors: Jeroen Klaasjan Verbrugge; Marcel Cornelis Den Hollander; Martinus Cornelis Van Scheppingen; John William Spaven; Dave Lambert Adrian Van Soest
Original assignee: Flex/Concepts B.V.
Priority date: 2007-04-11
Filing date: 2008-04-08
Publication date: 2008-10-23
Also published as: NL1033671C2; WO2008127088A3; EP2134213A2

Abstract

Device for height adjustment of a table top (2), such as a writing desk, which device comprises a support beam (1) and in which between this and the table top a lifting mechanism is present. The table top is near two opposite sides supported by a substantially V-shaped support (6) with arms (7, 8) the free ends of which are connected to the table top (2) by means of first pivot shafts (5). The top of each support (6) is connected to a first carriage (11) by a second pivot shaft (10), said carriage being movable along said support beam (1). The centre (9) of said V-shaped support (6) is connected to a lever (13), the other end of which is connected to a second carriage (17) movable along said support beam (1) by electro motoric driven means (18, 19, 20) or in an equal way.

Description

Device for height adjustment of a table top such as a working or writing desk.

The invention relates to a device for height adjustment of a table top, such as a working or writing desk, said device comprising a fixedly positioned support beam extending substantially parallel to the length of said table top, a lifting mechanism being positioned between said support beam and said table top for height adjustment of said table top, said mechanism comprising a support near each end of said table top, one end of each of said supports being rotatable connected to parts connected to said table top, the other end being movable along said suport beam, each support between said both ends being rotatable connected to a lever, the other end of which extends towards said support beam. Such a device is known by DE 1 909 471 Al. In case of this known device the table top is mounted to a beam connected to legs which are telescopical guided in columns which also serve for supporting said support beam. The means for adjusting the height of said table top comprise at least one screw- spindle.

In view of said telescopical guidings the dimensions of said lifting mechanism will have to be very exact to prevent blocking of said guidings.

By the presence of said telescopical guidings one is limited in the construction by which the support beam is supported onto the ground.

Now the object of the invention is to provide a device for height adjustment of a table top which does not have said telescopic guidings and the disadvantage resulting of this and further is more simple in construction.

According to the invention this is obtained by that along said support beam two carriages are movable, one for each of said supports , one end of each support being rotatable mounted to one of said carriages, such that said supports are only movable in one common plane perpendicular to said table top, the other end of said supports being directly rotatable connected to said table top. As according to the invention no telescopical guidings are necessary said support beam can be supported in very different ways. So the supporting can e.g. be done by legs which are making an angle with a horizontal plane. The suppor- ting can also be done by cabinets, drawer blocks, braces for wall connection or building elements in an office room, such as low walls. It is also possible to connect two beams to one support construction. Further configurations are possible in which three or four support beams are positioned in the shape of a star with one common leg and each with a leg at its free end.

In particular when said table top is used as a writing desk it is desired that the accessibility to said desk is as good as possible. This means that the user of said desk must hardly be hindered by said support beam, by the means supporting said support beam and by said mechanism serving for the height adjustment of said table top.

In view of this, according to the invention, the device can be executed such that the support beam, being provided with the lifting mechanism and the drive means of this, is positioned at a distance from the front edge of said table top, said distance depending on the width of said table top.

In practice said support beam will be positioned near the back edge of said table top when said table top is having a width of about 100 cm or less, said width measured in a direction perpendicular to the length of said support beam. When the width is e.g. 120 cm the support beam might be positioned near the middle of said table top. In both cases a user of said table top will not be hindered by said support beam. Obviously the table top must be supported as stable as possible. To obtain this said supports are substantially V- shaped, in which the two arms of each support might have a different length, the free ends of the two arms of each support being connected to first pivot shafts, lying parallel to, either in line with each other, and being connected to parts mounted to the table top, the top of each of said V-shaped supports, either directly or via an elongating member, being connected to a first carriage by means of a second pivot shaft, said carriage being movable along said support beam.

The substantially V-shaped support might also be formed by one arm extending from said support beam towards the other arm which is running parallel to said table top and is rotata- ble coupled with this. This, however, will give a less stable support of said table top and will require a very stiff connection between said arms.

According to a first embodiment the geometrical centre of each substantially V-shaped support is, by means of a third pivot shaft, connected to one end of a lever which is rotata- ble supported by a fourth shaft, running parallel to said earlier mentioned shafts and being supported by said support beam, the length of said lever, measured between said third pivot shaft and said fourth shaft, being equal to the distance between said third pivot shaft and said first and second pivot shaft, respectively, in which all distances are projected onto a plane extending square to said pivot shafts, the distance between said second pivot shaft and said table top being equal to the distance between said fourth shaft and said table top. In this way it is obtained, that in the lowest position of said table top the axes of said first pivot shafts of said V-shaped support and the axis of said fourth shaft can lie in line with each other. When moving the carriage, with which said second pivot shaft is connected, said first pivot shafts will move in a direction perpendicular to said table top.

By this said table top will be moved exactly perpendicular to its plane.

Now, moving the table top from the lowest position towards a higher position, in the beginning will require a considerable moment. This is in particular true when for this the carriage, on which the second pivot shaft is present, has to be brought into movement .

In connection with this it is provided for that to said lever either to said fourth pivot shaft connected to said lever, an arm is connected extending towards the suppport beam and which by at least one tension strip is connected to a second carriage being movable in said support beam by drive means . So said first carriage is freely movable and only serves for supporting said second pivot shaft on which the top of said substantially V-shaped support is pivotable.

For moving said second carriage use can be made of a screw spindle which rotatable but axially not movable is supported by bearings mounted in said support beam, said spindle co-operating with a nut fixedly mounted in said carriage.

For rotating said spindle use can be made of a single centrally positioned electric motor with gear box, said spindle at both ends being provided with right and left screw- thread respectively and the nut in both carriages being adapted to these.

Possibly use might be made of two similar spindles and nuts which, however, have to be driven in opposite directions.

The latter might be done by one single electric motor and possibly also by two electric motors which by electronic means are coupled with each other. These motors can be positioned at a distance from each other near the support beam. In this way it is obtained that an electric motor can be used which has to deliver relatively less power.

In stead of an electric motor use can also be made of a pneumatic or hydraulic driven motor either motors . Rotating the screw spindle might also be done by hand. A further possibility is also that both carriages are moved by means of hydraulic or pneumatic cilinders.

All these possibilities, however, will be obvious for the expert and do not need further description.

According to a second embodiment of the invention the two arms of said substantially V-shaped support are fixedly connected to an intermediate element, lying before said support beam as seen in vertical projection, said element being fixedly connected to an elongating member, being coupled to said carriage by said second pivot shaft, a driving lever being present which is rotatably mounted on said support beam by means of a driving shaft running parallel to said support beam, the free end of said lever co-operating with said intermediate element of said substantially V-shaped support. When said table top is in its lowest position said driving lever will nearly lie in a horizontal plane. By rotating said lever this will move said intermediate element and by this will rotate said substantially V-shaped support while the free end of said elongating member of said support will move along said support beam. By this said table top will be moved in upward direction .

During this movement obviously the upper end of said driving lever will move along said intermediate element. The co-operation between said lever and said intermediate element can be obtained in different ways . Said lever can be provided with a pin either a roller or such like which is taken up in a sleeve in said intermediate element.

Rotating of said driving lever in particular will take place by means of an electric motor with a gear box so that the speed of said driving lever can be adjusted.

Both connecting levers will be separately driven by an electric motor and the electric motors will be electronically coupled with each other, such that both connecting levers will synchroniously rotate in respect of each other.

By the construction as described it is obtained that there is always a given room between said support beam and said supports and between said supports as such. Further the total surface of elements moving towards each other is limited so that the risk of clenching body members is decreased.

In case of both embodiments it is important to provide means for locking the table top in a given position. This e.g. can be done by means of a pin which manually can be brought into openings in certain parts. So openings can be provided in the support beam and the carriages, such that these can be locked by pins in certain positions. It is also possible to lock the various levers e.g. by means of a clamping mechanism, which can be handled manually or with a simple device.

By electronical operation of electric motors used in the various embodiments it is preferred that the height adjustment mechanism is operated in two or more steps. When now said table top is moved in downward direction and reaches the last either the last but one position the electric motor will stop and a further downwardly movement can only take place when the operation element is again activated by the user.

The invention is further elucidated by means of two embodiments shown in the drawing, in which: Fig. 1 shows a perspective view of a first embodiment of a device according to the invention, in which, however, the table top is left out;

Fig. 2 shows a vertical longitudinal section of the device of fig. 1 with the table top mounted; Fig. 3 shows a view from below of the device of fig. 2;

Fig. 4 shows a perspective view of a second embodiment of a device according to the invention, in which, however, the table top is left out;

Fig. 5 shows a view in horizontal direction of the device of fig. 4 with the table top mounted; and

Fig. 6 shows a side view of the device of fig. 5.

The device, shown in the figures 1 - 3 of the drawing, comprises the support beam 1, which can be supported in different ways as this is described before. As in particular appears from fig. 3 the support beam 1 can be present near the back edge 3 of the table top 2 as seen in the lowest position of this. As already said before the support beam might be positioned at a distance from said back edge 3 dependent on the width of said table top 2. The table top 2 is provided with brackets 4 being in pairs connected to a V-shaped support 6 by means of two first pivot shafts 5 lying in line with each other. The support 6 has a short arm 7 and a long arm 8, lying in one plane but being bended somewhat in said plane, such that they are lying nearer to each other in the geometrical middle 9, as in particular appears from fig. 1.

By means of a second pivot shaft 10 the top of the V- shaped support 6 is connected to a first carriage 11 which is freely movable applied in the support beam 1. By means of a third pivot shaft 12 one end of a lever 13 is connected to the middle 9 of each V-shaped support 6, the other end of said lever 13 being pivotable by means of a fourth shaft 14, running parallel to the earlier mentioned shafts 5, 10 and 12. Said shaft 14 is supported by the support beam 1. The length of the lever 13, measured between the shafts 12 and 14 is equal to the distance between the shafts 5 and 12 and the distance between the shafts 10 and 12. All these distances are measured as projected on the plane of drawing of fig. 2.

As can be concluded from fig. 2 the distance between said table top 2 and said pivot shafts 10 is equal to the distance between said table top 2 and said pivot shafts 14 as seen in a direction perpendicular to said table top 2. In this way it is obtained that the table top 2, when being adjusted in height, will move exactly perpendicular to its plane. In the lowest position of the table top 2 the lever 13 will lie between the arms 7 and 8 of the V-shaped support 6. For the height adjustment of the table top 2, at both sides of this, said lever 13 is provided with a leverarm 15, which extends towards the support beam 1 and which, by at least one tension strip 16, is coupled with a second carriage 17 being shiftable in said support beam 1. Said tension strip 16 will be pivotably connected to said leverarm 15 as well as to the carriage 17. Preferably at both sides of said carriage 17 a tension strip 16 will be present, such that said carriage 17 is loaded in a more favourable way.

Said carriage 17 can be moved by means of a spindle 18, which is driven by an electric motor 19 and extends through a nut 20, which non rotatably is mounted in the carriage 17.

Because both carriages 17 have to be moved towards either away from each other when the table top 2 is moved in upward either downward direction, the spindles 18 and the related nuts 20 will have to be executed left either right rotating. Then one electric motor can be used. Generally speaking said electric motor will be provided with a gear box for decreasing the speed with which the spindles 18 are driven.

It is possible that the spindles 18 are separately driven by an electric motor. Then said electric motors will be electronically coupled with each other, such that both carriages 17 are synchroniously displaced in respect of each other.

Moving the carriages 17 can also be done in other ways as already remarked before. Obviously it is important that said carriages are moved over equal distances.

In case of the second embodiment, shown in figures 4 - 6, parts corresponding with the parts of the first embodiment are indicated with the same reference numbers.

As in case of the first embodiment the support beam 1 serves for supporting means for height adjustment of said table top 2 , being provided with brackets 4 which in pairs are connected to a substantially V-shaped support 6 by means of two first pivot shafts 5 lying in line with each other.

The support 6 has arms 7 and 8 which now are fixedly connected to an intermediate element 101, which in its turn is fixedly connected to an elongating member 102, being coupled to a carriage 11 by means- of said second pivot shaft 10. So said support 6 comprises the arms 7 and 8, the element 101 and the member 102, said parts forming one whole with each other.

A driving lever 103 is rotatably moounted on said support beam 1 by means of a driving shaft 104 running parallel to said support beam 1. The free end of said driving lever 103 co-operates with the intermediate element 101 of said substantially V-shaped support 6 in a not further described way.

It will be obvious that when the driving levers 103 are rotated from the positions shown in fig. 5, the supports 6 are rotated in the direction of the arrows P such that the table top 2 will move in upward diection. At the same time the carriages 11 will move away from each other.

Each driving shaft 104 can be driven by an electric motor 105, mounted in a bracket supported by said support beam 1. By electronic means it can be assured that said electric motors 105 are rotating the levers 103 over the same angle.

Locking members of the devices can e.g. be done by providing a number of openings in the support beam 1 and one or more openings in the carriages 11. In said openings a pin can be brought for locking the table top 2 in a given position. For compensating small deviations in the exact vertical linear movement of said table top 2 the shafts 5, coupling said supports 6 to said table top, can be mounted in bushings from elastic material, such as rubber or another material. At the same time said rubber bushings can serve for damping vibrations of said table top 2, which might occur when said table top is hit by a person or by another object.

It will be clear that only two possible embodiments of a device according to the invention are shown in the drawing and are described above and that many modifications can be applied without leaving the inventive idea, as this is indicated in the claims .

Claims

C L A I M S

1. Device for height adjustment of a table top (2), such as a working or writing desk, said device comprising a fixedly positioned support beam (1) extending substantially parallel to the length of said table top (2), a lifting mechanism being positioned between said support beam (1) and said table top (2) for height adjustment of said table top (2), said mechanism comprising a support (6) near each end of said table top, one end of each of said supports being rotatable connected to parts connected to said table top, the other end being movable along said suport beam (1), each support (6) between said both ends being rotatable connected to a lever (13,103) the other end of which extends towards said support beam (1), characterized in that along said support beε.m (1) two carriages (11) are movable, one for each of said supports (6), one end of each support being rotatable mounted to one of said carriages (11), such that said supports (6) are only movable in one common plane perpendicular to said table top (2), the other end of said supports (6) being directly rotatable connected to said table top (2).

2. Device according to claim 1, characterized in that the support beam (1), being provided with the lifting mechanism and the drive means of this, is positioned at a distance from the front edge of said table top (2), said distance depending on the width of said table top (2).

3. Device according to claim 1 or 2, characterized in that said supports (6) are substantially V-shaped, the ends of the two arms (7,8) of each support (6) being connected to first pivot shafts (5), lying parallel to either in line with each other, and being connected to parts (4) mounted to the table top (2), the top of each of said V-shaped supports (6), either directly or via an elongating member (101,102), being connected to said first carriage (11) by means of a second pivot shaft (10).

4. Device according to claim 3, characterized in that the geometrical centre (9) of each V-shaped support (6) is, by means of a third pivot shaft (12), connected to one end of a lever (13) which is rotatable supported by a fourth shaft (14), running parallel to said earlier mentioned shafts (5,12, 10) and being supported by said support beam (1), the length of said lever (13), measured between said third pivot shaft (12) and said fourth shaft (14), being equal to the distance between said third pivot shaft (12) and said first (5) and said second (12) pivot shaft, respectively, in which all distances are projected onto a plane extending perpendicular to said pivot shafts, the distance between said second pivot shaft (10) and said table top (2) being equal to the distance between said fourth shaft (14) and said table top (2).

5. Device according to claim 3 or 4 , characterized in that to said lever (13) either to said fourth pivot shaft (14) connected to said lever (13), an arm (15) is connected extending towards said suppport beam ( 1 ) and which by at least one tension strip (16) is connected to a second carriage (17) being movable in the support beam (1) by drive means (18,19, 20).

6. Device according to claim 5, characterized in that for moving the second carriage (17) use can be made of a screw spindle (18) which rotatable but axially not movable is supported by bearings mounted in said support beam (I)_/ said spindle (18) co-operating with a nut (20) fixedly mounted in said carriage (17).

7. Device according to claim 6, characterized in that for rotating the spindle (18) use is made of a single centrally positioned electric motor (19) with gear box, said spindle (18) at both ends being provided with right and left screw- thread respectively and the nut (20) in both carriages (17) being adapted to these.

8. Device according to one of the claims 1 to 3, characterized in that the two arms (7,8) of said V-shaped support (6) are fixedly connected to an intermediate element (101), lying before said support beam (1) as seen in vertical projection, said element (101) being fixedly connected to an elongating member (102), being coupled to said carriage (11) by said second pivot shaft (10), a driving lever (103) being present which is rotatably moounted on said support beam (1) by means of a driving shaft (104) running parallel to said support beam (1), the free end of said lever (103) co-operating with said intermediate element (101) of said arms (7,8) of said V-shaped support ( 6 ) .

9. Device according to claim 8, characterized in that each driving shaft (104) is driven by an electric motor (105), supported by said support beam (1), electronic means being present for assuring that said electric motors (105) are rotating the levers (103) over the same angle.

10. Device according to one of the preceding claims, characterized in that means are present for locking parts of the device in a given position, said means in particular being manually operated.

11. Device according to claim 10, characterized in that said means are formed by pins which manually can be brought into openings provided in given parts .

12. Device according to one or more of the preceding claims, characterized in that in case of electronical operation of said mechanism, for height adjusting of said table top (2) by means of one or more electric motors (19,105) said mechanism is operated in two or more steps, such that in particular when said table top (2) is moved in downward direction and reaches the last either the last bat one position the electric motor (19,105) will stop and further movement in downward direction can only take place when the operation element is again activated by the user.