EP1093732B1

EP1093732B1 - Support for a height-adjustable table and method of manufacturing same.

Info

Publication number: EP1093732B1
Application number: EP00203367A
Authority: EP
Inventors: Gerardus Henrikus Maria Geerts
Original assignee: Koninklijke Ahrend NV
Current assignee: Koninklijke Ahrend NV
Priority date: 1999-10-08
Filing date: 2000-09-29
Publication date: 2006-03-08
Anticipated expiration: 2020-09-29
Also published as: NL1013255C2; EP1093732A1; ES2259281T3; DE60026445T2; PT1093732E; ATE319353T1; DE60026445D1

Abstract

The invention relates to a support for a height-adjustable table having at least one height-adjustable leg, consisting of an outer and an inner leg and means for height-adjustment of the leg. The means are completely concealed in the legs and substantially comprise a strip of resilient material to be mounted under tension in the outer leg and having its free end provided with a locking member, said locking member cooperating with complementary locking means mounted in the inner leg. The locking member can be brought in and out of locking engagement through an opening in the outer leg. <IMAGE>

Description

The invention relates to a support for a height-adjustable table or similar bearing surface comprising at least one height-adjustable leg, consisting of an outer and an inner leg and means for height-adjustment of the leg.
With such tables, there is a distinction between systems in which the leg or legs can be adjusted to a number of height positions per individual leg, and systems in which the leg or legs can be adjusted in height across a certain range using a centrally operated system, which takes place with a number of legs at the same time. The invention relates to the first system in particular, in which the adjustment should be changed per individual leg, and which can be manufactured at essentially lower costs in relation to the second system.
A very simple embodiment of such a system is a system having a series of holes mounted at several heights in the inner leg, or in inner and outer leg opposite each other, through which holes a pin can be stuck at the desired height. Although such a system functions adequately, it does not represent a design that can satisfy in e.g. present-day stylish office furniture. Document DE-U-29818599 discloses a support according to the preamble of independent claim 1.
Therefore, the object of the invention is to provide for a support for a table having a height-adjustable leg (or legs) in which the means for height-adjustment of the leg (or legs) do not protrude from the legs, that they can be operated in a convenient and simple way, and can furthermore be manufactured at relatively low cost.
Thus, according to the invention a support according to independent claim 1 is provided.
The major advantage is that the locking means are now entirely incorporated in the inner and outer legs and are not visible from the outside. This also greatly improves the safety of the entity and provides the possibility of a much more attractive design of table and support, which will not be disturbed by the locking means in any way.
Preferably, the strip of resilient material is made of metal, such as steel or spring steel, for example, which is able to exert a sufficiently large spring force across the length of the strip and furthermore can be easily mounted into an outer leg. The locking member can be integral with the strip, however, it is preferred to manufacture the locking member separately, and then mount it at or near the outer end of the strip. Therefore, the locking member is preferably made of aluminium or of a plastic, due to which it is possible to model the locking member exactly after the complementary locking means in the inner leg in a simple way.
Further, it has been provided for, that the guiding portion and the locking portion of the locking member have been mounted at that side of the strip of resilient material which faces the inside of the outer leg, the guiding portion in relation to said side of the strip of resilient material which faces the inside of the outer leg projecting further than the locking portion.
Through this, it is achieved that on releasing the locking portion from the locking recesses in the inner leg for height-adjustment of a leg, the locking member still remains in the guiding slot made in the inner leg with its locking portion, and with that, except for the heigth, the positioning of the locking portion in relation to the locking recesses is maintained.
For releasing the locking in order to be able to make the height-adjustment, the locking member, at least its locking portion, should be brought out of the locking recesses from the outside. To this end, an opening has been made in the outer leg at the level of said locking member, into which, in relation to said locking portion, the projecting portion of the guiding portion is intended to be located. There, the projecting portion of the guiding portion is formed in such a way, that it fits closely to the circumference of the opening and will come to lie exactly in the outer plane of the outer leg, so that there won't be any disturbance in the design of the table or furniture having a comparable function either.
In order to prevent the guiding portion from being pushed out of the guide too far, and thus possibly making the complete return movement of the strip of resilient material impossible, it has been provided for that a stop part projecting into the direction of the opposed inner side of the leg is mounted on said locking member or on the strip of resilient material, at the other side then where said guiding portion and locking portion are located.
According to a further elaboration, it has been provided for, that the locking portion consists of cams mounted at both sides of the guiding portions, said cams protruding laterally in relation to said guiding portions, with the cams of the locking portion, seen in normal position, having a plane approximately horizontal and being square to the longitudinal direction of the legs at the bottom side, said cams being provided with edge portions at the edge of said plane projecting downwards spaced from the strip of resilient material.
Through this, the weight of a table rests on the inner leg or inner legs through one or more strips of resilient material and the horizontal contact planes of the cams of the locking member with the locking recesses in the inner leg or inner legs. The edge portions on the cams provide for that the cams can only be disengaged from the locking recesses by first moving the outer leg upwards across a small distance. This prevents the possibility that hitting against the projecting part of the locking portion might release the locking and possibly make the table shoot downwards or tilt.
In order to provide for that between inner and outer legs there is enough room for at least the parts of the locking portion or the cams where the edge portions are located, guiding means have been mounted between said inner and outer legs, in such a way that at the level of the strip of resilient material mounted in the outer leg and the guiding slot mounted in the inner leg and the locking recesses, said inner and outer legs are kept at least at a predetermined distance from each other.
The invention also comprises a method of manufacturing a support according to independent claim 10.
Preferably, for tables having an even number of legs, the outer legs are formed in pairs from one continuous pipe portion, in which a set of inner legs is used to form a complete yoke for a height-adjustable table. By using two of such yokes, one or more beams to be mounted between said yokes and a table top, it is possible to assemble a height-adjustable table. Then, the method comprises the additional steps of:

making recesses and incisions in a pipe portion for being able to make a yoke with two outer legs from said pipe portion;
mounting the strips of resilient material after making the recesses in the outer leg representing parts of said pipe portion;
bending the pipe portion into a yoke with two outer legs and welding the seams.

In the following, the invention is further explained by way of the example given in the drawing, in which:

Fig. 1 shows a height-adjustable table in a perspective view;
Fig. 2 shows a cross-sectional view of the table;
Fig. 3 shows a plan view of the table;
Fig. 4 shows a detail of the connection of a beam with a yoke;
Fig. 5 shows a cross-sectional view of an outer leg with a strip of resilient material;
Figs. 6A,B show a lateral view and a plan view, respectively, of a strip of resilient material with a locking member;
Figs. 7A,B,C are views of a pre-treated pipe portion for a yoke having two outer legs;
Figs. 8A,B show two different perspective views of a locking member;
Figs. 9A,B show views of two sides of an inner leg;
Fig. 10 shows a cross-section along the line X-X in Fig. 9B;
Figs. 11A,B show two different perspective views of guiding means to be mounted between inner and outer leg; and
Figs. 12A,B,C show a view, a longitudinal cross-section and a lateral cross-section, respectively, of telescoped inner and outer legs.

Figs 1, 2, 3 show a height-adjustable table 1 consisting of a support having inner legs 2, 3, 4, 5, outer legs 6, 7, 8, 9 partially overlapping them, said outer legs 6, 7 and 8, 9 being connected to horizontal intermediate parts 10, 11 and forming yokes 12, 13. Beams 14, 15 to which the table top has been secured have been mounted between said yokes.
Fig. 4 shows in more detail the connection of a beam 14 to a horizontal portion 11 of yoke 13. To that end, a fastening plate 17 is mounted in an opening made in horizontal part 11, said fastening plate being at least provided with a threaded hole 18 intended for receiving bolt 19. Preferably, the fastening plate 17 is further provided with one or more recesses intended for receiving protruding parts or pins lying on the outer end of beam 14, as a consequence of which the positioning of the beam 14 in relation to the fastening plate 17, and with that in relation to the yoke 13, is fixed. Preferably after forming the yoke, the fastening plate 17 is mounted with the help of a positioning jig, so that possible deviations in manufacture can be overcome.
The beam consists of a part 20 extending across the major part of the length, said part having a smaller height than the part 21 mounted at the outer ends, which represents a transition from said smaller height to the height of horizontal part 11. This provision causes the available space (for the legs) underneath the table to be as optimal as possible.
Further, the cross-section of horizontal part 11 shows an outer end of a strip of resilient material 22, which is the outer end by which the strip 22 has been fastened to the inner side of the outer leg 6.
Fig. 5 shows a cross-section through an outer leg 6 and a part of a horizontal part 11, the mounted strip 22 being visible in cross-section as well. The strip 22 is fastened at the uppermost end 23 within the outer leg 6. Outer end 23 is followed by a short part 24 bounded at both sides by opposed bends and a long part 25 having a locking member 26 at the free end. The bends are of such nature that the strip 22, after fastening, together with the locking member 26 will end up lying under tension against said outer leg 6, and partly within an opening 31 made in said outer leg 6.
In Figs. 6A,B, the strip 22 is shown in more detail. A number of bulges 27, 28, 29 have been made in the uppermost end 23 for being able to fasten the strip 22 in the outer leg 6 by means of projection welding. In its free end, the strip 22 is provided with a slot 30 for receiving the locking member 26. After bringing said locking member 26 in the slot 30, the end of the slot is squeezed to such an extent, that the locking member will get stuck on the strip 22.
Figs. 7A,B,C show bottom, side, and plan views, respectively, of a pipe portion from which a yoke 13 can be formed. To this end, cut- outs 32, 33 have been made in the pipe portion between which is intended to be the horizontal part 11 and the outer legs 6, 7, and cut- outs 34, 35 in which the fastening plates 17 for the beams 14, 15 are to be mounted. Further cut-outs not illustrated in the figure are the openings 31 in the outer legs 6, 7 in which the locking members 26 will partly come to lie. Said cut-outs are preferably made with a laser cutting device, in order to obtain a cut which is as straight and firm as possible.
After making the cut- outs 32, 33, nicks are made in the pipe portion according to the lines 36, 37, at the location where the pipe portion is to be bent. Then, before bending and welding-up the seams, strips 22 are brought into the outer legs 6, 7 and after positioning the locking members 26 in relation to the openings, they are secured in the outer legs 6, 7 by means of projection welding. Welding-up the seams between outer legs 6, 7 and the horizontal portion occurs preferably by TIG-welding so as to obtain a seam which is as smooth and straight as possible.
Figs. 8A,B show perspective views of the locking member 26. Locking member 26 has an elongate body 38 having parallel sides 40, 41 and circular or rounded outer ends 42, 43. In body 38, a groove 39 has been made, at the height of which the locking member can be slid into the slot and across strip 22. Cams 44, 45 have been applied at both sides 40, 41 of said body 38 above groove 39. Seen in Fig. 8a, the top surfaces of cams 44, 45 are situated lower than the top surface 46 of body 38. This difference in height preferably corresponds to the wall thickness of an outer leg 6 due to which the top side 46 can be aligned with the outer surface of an outer leg 6.
The straight faces 47, 48 of cams 44, 45 come to bear on the horizontal limits of locking recessions provided in the inner leg 2, and the edge portions 49, 50 provide for that the cams can only be released from the locking recesses by moving the outer leg upwards across a small distance first.
At its lower side, the locking member is additionally provided with a projecting pin 51, which serves as a stop for preventing the locking member 26, and with it the strip 22, from being pushed too far into the legs. The length of the pin 51 depends on the shape and diameter of the legs employed.
Figs. 9A,B show two different sides 52, 54 of an inner leg 2, having the shape of an isosceles triangle when seen in cross-section. The side 54 has a cut-out 55 substantially consisting of a central slot 56 and at both sides thereof and following it, series of locking recesses 57, 58. The width of slot 56 is such that the central body 38 of the locking member with the sides 40, 41 parallel to the longitudinal direction of the central slot 56 fits into it. Cams 44, 45 fit exactly into opposite recesses 57, 58. The width of the strip 22, which will come to lie in the inner leg behind central slot 56, is of course greater than the width of central slot 56.
Further, it is also possible to provide the locking recesses at a distance from the central slot 56 and designing the locking member correspondingly, but this is not the most economical variant.
Further, the guiding means illustrated in Figs. 11A,B have been provided, which substantially consist of a strip 63 to be mounted around the inner leg 2. At least one strip is mounted at both sides of the cut-out 55. A number of bores 59, 60, 61, 62 for fastening of the strips have been provided in the inner leg 2, see Fig. 10, into which the bulges 64, 65, 66, 67 at the inside of strip 63 are intended to fall. When telescoping inner and outer leg, the guiding strips 63 will then be fixed in their positions in relation to the inner leg.
A spacer 68 has been mounted at the outside of strip 63, at the side corresponding to the side 54 of the inner leg 2 where the cut-out 55 has been made. Said spacer 68 serves for maintaining a sufficient distance between the inner side of outer leg 6 and the outer side 54 of inner leg 2, in order to have enough space for moving the cams 40, 41 with the edge portions 49, 50 over the edges of locking recesses 57, 58.
Fig. 12A shows a telescoped inner and outer leg 2, 6 with the locking member 26 situated in the opening 31 made in the outer leg 6. The inner leg 2 is further provided with an adjustment foot 69.
Fig. 12B shows a longitudinal section through inner and outer legs 2, 6 in which the long portion 25 of the strip of resilient material 22 and locking member 26 provided near its end are clearly visible. The figure also shows groove 39 by which the locking member can be brought into slot 30 of the strip 22. The strip 63 of the guiding means is situated at the top side, with its bulge 64 projecting through the opening 59 being further visible.
The cross-section across Fig. 12C then shows the laterally protruding cams 44, 45 of locking member 26 and the guiding strip 63 mounted between inner and outer legs 2, 6 and situated below locking member 26.

Claims

Support for a height-adjustable table (1) or similar bearing surface comprising at least one height-adjustable leg, consisting of telescoping outer (6-9) and inner leg (2-5) and means for height-adjustment of the leg, said means comprising a resilient strip (22) mounted in the outer leg (6-9) and having an outer end (23) secured to the inside of the outer leg (6-9), characterised in that a locking member (26) is mounted at the opposite free outer end of the resilient strip (22), the outer (6-9) and inner leg (2-5) being provided with openings (31,56,57,58) for the locking member (26), with the resilient strip (22) extending inside the inner leg (2-5) and that the locking member (26) comprises a guide portion(38) and a locking portion (44,45,47,48), the guide portion (38) being intended for engaging a guiding slot (56) in the inner leg (2-5) and the locking portion (44,45,47,48) being intended for engaging locking recesses (57,58) adjacent said guiding slot (56).
Support according to claim 1, characterized in that the guiding portion (38) and the locking portion (44,45,47,48) of the locking member (26) in the locking position protrude through the inner leg (2-5) with the guide portion (38) projecting further than the locking portion (44,45,47,48).
Support according to claim 3, characterized in that the locking portion (44,45,47,48) consists of cams (44,45) mounted at both sides of the guiding portion (38), said cams (44,45) protruding laterally in relation to said guiding portion (38).
Support according to claim 3, characterized in that the cams (44,45) of the locking portion (44,45,47,48) at their bottom sides have a plane approximately horizontal and approximately perpendicular to the longitudinal direction of the inner leg, in which said cams (44,45) are provided with edge portions (46) projecting downwards near or at the edge of said plane, at a distance from the strip of resilient material (22).
Support according to claims 2 - 4, characterized in that a stop part (51) projecting into the direction of the opposed inner side of the leg (2-5) is mounted on said locking member (26) or on the strip of resilient material (22), at the other side than where said guiding portion (38) and locking portion (44,45,47,48) are located.
Support according to claims 1 - 5, characterized in that guiding means (63) have been mounted between said inner (2-5) and outer legs (6-9), in such a way that at the level of the strip of resilient material (22) mounted in the outer leg (6-9) and the guiding slot (56) mounted in the inner leg (2-5) and the locking recesses (57,58), said inner (2-5) and outer legs (6-9) are kept at least at a predetermined distance from each other.
Support according to claims 1-6, characterized in that inner (2-5) and outer leg (6-9) consist of three-sided or multiple-sided pipe portions.
Support according to claim 7, characterized in that the outer legs (6-9) are formed in pairs of continuous pipe portion and a bent pipe portion and together with a pair of loose inner legs (2-5) form a yoke (12,13) in said support.
Support according to claim 8, characterized in that a pair of yokes (12,13) with one or more beams to be fastened between the horizontal parts of the yokes together form a support.
Method of manufacturing a support according to one or more of the claims 1 - 9, characterized in that said method comprises at least the following Steps:
- pre-beading a strip of resilient material;

- mounting a pre-formed locking member (26) to the outer end of said strip;

- making an opening (31) in the outer pipe at the point where the locking member (26) is intended to end in the outer pipe;

- making the guiding slot (56) and the locking recesses (57,58) into the inner pipe;

- securing the strip (22) of resilient material in the correct position within the outer pipe; and

- telescoping said inner and outer pipes.
Method according to claim 10, characterized in that it further comprises the following steps of:
- making recesses and incisions in a pipe portion for being able to make a yoke (12,13) with two outer legs from said pipe portion;

- mounting the strips (22) of resilient material after making the recesses in the outer leg representing parts of said pipe portion;

- bending the pipe portion into a yoke (12,13) with two outer legs and weld ing the seams.
Method according to claims 10-11, characterized in that a strip (22) of resilient material is mounted to the outer leg by means of projection welding.
Method according to claims 10 -12, characterized in that the recesses are made with a laser cutting device.
Method according to claims 10 -13, characterized in that it further comprises the following steps:
providing recesses for fastening means for one or more beams to be mounted between successive yokes (12,13), in the portion of the yoke loca ted between the outer legs;

mounting the fastening means into the recesses after forming the yoke (12,13) in a positioning jig.