(51) Int. Cl.3:

R. Rüger, Dr. Eng., and H. P. Barthelt, Grad. Eng., Patent Attorneys

Admitted Representatives at the European Patent Office

Webergasse 3 - Post Office Box 348 - 7300 Esslingen (Neckar)

June 30, 1983

RA 1 rüal

Telephone Stuttgart

(0711) 36 65 39 and 35 96 19

Fax 7 256 610 smru

Telegram Patent Protection

Esslingenneckar

Patent Claims

1. Height adjustable table or the like comprising a foot frame, which exhibits at least one stably constructed foot, on which is mounted so as to be vertically adjustable a carrier, which is holding the table top and which is lockable selectively at its respectively set height level, characterized in that the carrier (2) is mounted on the foot (4) by means of a parallelogram lever mechanism (7), which has two parallel articulated levers (8, 9), which are spaced apart one above the other and which are linked at one end to the foot (4) and at the other end to the carrier (2), forming a coupling rod, so as to be swivellable about parallel articulated axes; that the foot (4) exhibits a stationary engagement disk (15), which has engagement recesses (16), with which engagement recesses (16) an engagement element (14), arranged at the end of one of the articulated levers, can be brought into engagement while at the same time the articulated lever (8) locks into a fixed position; and that the articulated lever (8), which is constructed as two arms and which bears the engagement element (14), is mounted on the foot (4) so as to be longitudinally displaceable to a limited extent in the longitudinal direction of the lever by a path that is sufficient to lift the engagement element (14) out of the engagement recesses (16) in the engagement disk (15).

2. Table, as claimed in claim 1, characterized in that the mounting (11), which is longitudinally displaced to a limited extent, exhibits an oblong hole (120), which is configured in the articulated lever (8) and with which a journal (13), arranged on the foot (4), engages.

3. Table, as claimed in any one of the preceding claims, characterized in that the lever arm (8b), bearing the engagement element (14), is shorter than the lever arm (8a), connected to the carrier (2).

4. Table, as claimed in any one of the preceding claims, characterized in that the engagement element is an index bolt (14).

5. Table, as claimed in any one of the preceding claims, characterized in that at least one of the articulated levers (8, 9), which is constructed as two arms, is subject to the effect of a force, which counterbalances the weight of the table top (1) and which attacks at the lever arm of the articulated lever that faces away from the carrier (2).

6. Table, as claimed in claim 5, characterized in that the force is in essence constant.

7. Table, as claimed in claim 5 or 6, characterized in that the force is a spring force.

8. Table, as claimed in claim 7, characterized in that one end of the lever arm (9b) is attacked by at least one tension spring (17), which is anchored at the other end on the foot (4).

9. Table, as claimed in claim 8, characterized in that the spring (17) is disposed in the foot (4), which is configured like a housing; and that its assigned lever arm (9b) of the articulated lever (9) is shorter than the lever arm (9a), which is connected to the carrier (2).

10. Table, as claimed in any one of the claims 5 to 9, characterized in that the force attacks at the upper articulated lever (9), which is linked to the foot (4) so as to be able only to swivel; and the lower articulated lever (8) bears the engagement element (14).

11. Table, as claimed in any one of the claims 7 to 10, characterized in that a cable pull (25), which is anchored at one end to the lever arm, is connected to the lever arm (9b) of the articulated lever (9), said cable pull being guided over at least one stationary deflecting point (27), which is arranged on the foot (4) below the lever arm (9b); and that the spring force attacks the cable pull.

12. Table, as claimed in any one of the preceding claims, characterized in that the foot (4) is arranged in the vicinity of the front rim edge (22) of the table top (1) and exhibits a foot component (5), which branches off laterally and extends in the direction of the rear rim edge of the table top (1); and that the carrier (2) is configured essentially in the shape of an L and is connected on the end of its preferably horizontally extending leg to the table top (1).

13. Table, as claimed in any one of the preceding claims, characterized in that the foot frame (3) exhibits two feet (4), which are spaced apart side by side and are rigidly and releasably connected together and of which each foot is assigned a parallelogram lever mechanism (7), which is coupled to the carrier (2); and that the corresponding articulated levers (9) of both parallelogram lever mechanisms (7) are coupled rigidly and releasably together by means of at least one connection element (20).

Mr. Matthias Kompauer, Uhlandstrasse 11, 7441 Kohlburg

Height Adjustable Table or the Like

The invention relates to a height adjustable table or the like with a foot frame, which exhibits at least one stably constructed foot, on which is mounted so as to be vertically adjustable a carrier, which is holding the table top and which is lockable selectively at its respectively set height level.

In practice there exist tables with height adjustable table tops. In this case the height of the table top is adjusted by means of spindles and a handcrank; or the foot frame exhibits gas pressurized springs, on which the table top is mounted and to which hand-operable locking devices are assigned. The foot frames of all of these tables require separate operating elements. Furthermore, they cannot be disassembled into easy to handle parts for the purpose, for example, of storage or transport.

Therefore, the object of the invention is to provide a height adjustable table, which exhibits a sturdy foot frame, which allows the height of the table top to be adjusted quickly and reliably and in an uncomplicated way over a large adjustment range without requiring separate operating elements or locking devices that have to be released and tightened again by hand.

In order to achieve this object the aforementioned height adjustable table is characterized, according to the invention, in that the carrier is mounted on the foot by means of a parallelogram lever mechanism, which has two parallel articulated levers, which are spaced apart one above the other and which are linked at one end to the foot and at the other end to the carrier, forming a coupling rod, so as to be swivellable about parallel articulated axes; that the foot exhibits a stationary engagement disk, which has engagement recesses, with which engagement recesses an engagement element, arranged at the end of one of the articulated levers, can be brought into engagement while at the same time the articulated lever locks into a fixed position; and that the articulated lever, which is constructed as two arms and which bears the engagement element, is mounted on the foot so as to be longitudinally displaceable to a limited extent in the longitudinal direction of the lever by a path that is sufficient to lift the engagement element out of the engagement recesses in the engagement disk.

In order to adjust the height of the table top, the table top has only to be tilted - for example, by lifting up at one edge - slightly about an articulated axis of the parallelogram lever mechanism. In so doing, the articulated lever, bearing the engagement element, is displaced longitudinally in its mounting on the foot so far that the engagement element is lifted out of the engagement disk. As a result, the table top can be freely conveyed into the respectively desired vertical position, in which the table top is locked by tipping the table top back again into the working position by the small amount, so that the engagement element engages again with the engagement disk.

Therefore, on the one hand, the height is adjusted without having to activate any operating elements whatsoever, whereas, on the other hand, the engagement mechanism guarantees that the table top is locked and held securely and reliably in the respective working position.

In a preferred embodiment the articulated lever, which is mounted so as to be longitudinally displaceable to a limited extent and which interacts with the engagement disk, exhibits an oblong hole, which is configured in the articulated lever and with which a journal, arranged on the foot, engages. It is also practical for the lever arm, bearing the engagement element, to be shorter than the lever arm, connected to the carrier, whereas especially simple design conditions are produced if the engagement element is an index bolt.

In order to facilitate the handling, at least one of the articulated levers, which is constructed as two arms, is subject advantageously to the effect of a force, which counterbalances the weight of the table top and which attacks at the lever arm of the articulated lever that faces away from the carrier. Especially in the event of a large adjustment stroke of the table top it is expedient for this force to be in essence constant. It can be a spring force, for which purpose then one end of the lever arm can be attacked by at least one tension spring, which is anchored at the other end of the foot. Said tension spring can also be disposed in the foot, which is configured like a housing. In this case the lever arm, which belongs to the articulated lever and is assigned to said tension spring, is shorter than the lever arm, which is connected to the carrier.

In principle, the force can attack at each of the two articulated levers of the parallelogram lever mechanism, but it is advantageous for the arrangement to be configured in such a way that the force attacks at the upper articulated lever, which is linked to the foot so as to be able only to swivel, whereas the lower articulated lever bears the index bolt.

In the case of standard springs, as the spring excursion increases, the spring force increases in a manner known in the prior art as a function of the spring characteristic. If such a spring is used, then it is possible to accurately counterbalance the weight of the table top in just one vertical position. This is irrelevant especially in the case of light-weight table tops and a smaller vertical adjustment stroke. However, a uniform counterbalancing of the weight over the whole range of the adjustment stroke can be achieved in a simple way by connecting a cable pull, which is anchored at one end to the lever arm, to the lever arm of the corresponding articulated lever. Said cable pull is guided over at least one stationary deflecting point, which is arranged on the foot below the lever arm; and the spring force attacks the cable pull. Owing to the fact that when the height of the table top is adjusted, the lever arm of the articulated lever moves with its end on an arc of a circle about the articulated point, the effective lever arm, at which the cable pull attacks, changes automatically in the sense that the spring force, which changes with the spring excursion, is balanced at least substantially.

From a design viewpoint it is especially advantageous for the foot to be arranged in the vicinity of the front rim edge of the

table top and to exhibit a foot component, which branches off laterally and extends in the direction of the rear rim edge of the table top. In this case the carrier is configured essentially in the shape of an L and is connected on the end of its preferably horizontally extending carrier to the table top.

Whereas small tables or the like can make do with only one foot and one parallelogram lever mechanism, it is practical for larger table tops if the foot frame exhibits two feet, which are spaced apart side by side and are rigidly connected together. Each of the two feet is assigned a parallelogram lever mechanism, which is coupled to the carrier. At the same time the corresponding articulated levers of both parallelogram lever mechanisms are coupled rigidly together by means of at least one connection element.

This table can be disassembled very easily by removing the connection element and the connection of the two feet, so that only low storage and transport costs are incurred, whereas, on the other hand, this table can also be assembled by laymen.

The table can be used in general as a workbench whenever it is a matter of being able to adjust quickly and in an uncomplicated way the height of the table top, while at the same time a high degree of stability is guaranteed. This is important, for example, in the case of workbenches for young adults, school benches, office tables, and also in the case of tables

for industrial purposes, since it is also possible to erect another element, whose height is also supposed to be correspondingly adjustable, on the table top or, instead of the table top, on the foot frame.

The drawings depict the embodiments of the subject matter of the invention.

Figure 1 is a perspective view - to some extent a sectional view - of a height adjustable table, according to the invention.

Figure 2 is a side view of the foot frame of the table in Figure 1 with a partially opened foot.

Figure 3 is a side view and a partial view of the foot frame in Figure 1.

Figure 4 is a partial view and a side view on a different scale of the locking mechanism of the foot frame in Figure 2.

Figure 5 is a side view of a detail of the configuration in Figure. 4.

Figure 6 is a modified embodiment and a side view of the foot frame of the table in Figure 1.

Figure 7 is a different side view of a detail of the foot frame in Figure 6.

Figure 8 is a corresponding view of the foot frame in Figure 6 that depicts a different height adjustment.

The height adjustable table, shown in Figure 1, exhibits a table top 1, which is indicated by the dashed line and marked with the reference numeral 1. The table top is mounted on two carriers 2 so as to be tiltable about a horizontal axis. The two carriers in turn are mounted on a foot frame 3 so as to be vertically adjustable.

The foot frame 3 has two housing-like, vertical, stable feet 4, which are arranged in the vicinity of the front rim edge of the table top 1 and sit on two longitudinal foot components 5, which extend in the direction of the rear rim edge of the table top 1 and are rigidly connected together by means of a transverse rail 6. Each of the essentially L-shaped carriers 2 is mounted on the related foot 4 by means of a parallelogram lever mechanism 7, which exhibits two parallel articulated levers 8, 9, which are spaced apart one on top of the other and which are linked at one end at 10, 11 to the foot 4 and at the other end at 12, 13 to the vertical leg of the carrier 2, so as to be swivellable about the parallel articulated axes. In this case the carrier 2 forms a coupling rod of the parallelogram lever mechanism 7. The two articulated levers 8, 9 are constructed as two armed levers respectively (Figure 2). In this respect the longer lever arm 8a or 9a is connected to the carrier 2, whereas the shorter lever arm 8b or 9b projects into the foot 4. The lower articulated lever 9 is mounted at the articulated point 11 by means of an oblong hole 120 on a journal 13, which is arranged on the foot 4, so as to be swivellable and longitudinally displaceable to a limited extent in the longitudinal direction of the lever. The lower articulated lever bears on the end of its short lever arm 9b

an engagement element in the shape of an index bolt 14, whereas an engagement disk 15 is arranged on the foot 4. Said engagement disk is provided with engagement recesses 16, with which the index bolt 14 can engage, in order to lock the articulated lever 9 and, thus, the parallelogram lever mechanism 7 in its respective position. The oblong hole 120 allows the articulated lever 9 to be slid so far that the index bolt 14 is lifted out of the engagement recesses 16 of the engagement disk 15.

In the embodiment, according to Figure 2, a tension spring 17 attacks the short lever arm 8b of the upper articulated lever 8. This tension spring is fastened to the lever arm 8b by means of a spring bolt 18 (Figure 3) and is anchored at the other end to the foot 4 by means of a spring bolt 19. The springs 17, which are assigned to the two parallelogram lever mechanisms 7, are designed in such a way that they counterbalance the weight of the table top 1.

Between the lower articulated levers 9 of the two parallelogram lever mechanisms 7 there extends a connection element 20, which is constructed in the shape of a rod and which couples rigidly together the two parallelogram lever mechanisms and which is screwed at one end to the two articulated levers 9. Following removal of the rod 20 and the transverse rail 6, which is also screwed to the foot components 5, as well as two rails 21, which connect together the carriers 2 (and which are also screwed together at one end), the foot frame 3 is disassembled so that it can be stored and transported in a space-saving way.

In the state, depicted in Figures 1 and 2, the table top 1 is held rigidly in the set height position by means of the two parallelogram lever mechanisms, which are locked in a fixed position by locking their index bolts 14 into an engagement recess 16 of the engagement disk 15 in the manner shown in Figures 2 and 4.

In order to adjust the height level of the table top 1, it suffices to lift somewhat the table top at its front edge 22 in the direction of the component 23 (Figure 1). In so doing, the table top is swivelled slightly together with the carriers 2 about the horizontal articulated axis, which runs through the articulated points 12. The result of this counter-clockwise swivelling of the carriers 2 is that the lower articulated arms 9 are longitudinally displaced in the direction of the component 24 (Figure 2) (a state that is enabled by the oblong holes 120) and are lifted out of the engagement recesses 16, in particular, as far as the index bolts 14.

In this way the table top 1, whose weight is counterbalanced by the springs 17, can be set at any height level so as to be unimpeded by the engagement disk 15. In order to lock the table top at its new height level, only the front edge 22 of the table top 1 has to be released. In so doing, the lower articulated lever 9 is slid back again in the opposite direction of the arrow 24; and the index bolts 14 are locked in the respectively assigned engagement recess 16.

Whereas in the described embodiment, according to Figures 1 to 5, the tension spring 17 is linked directly to the shorter lever arm 8b of the upper articulated lever 8 in the case of each of the parallelogram lever mechanisms 7, the arrangement in the embodiment, shown in the Figures 6 and 8 in the two different height settings, is configured in such a way that the tension spring 17 is connected to the lever arm 8b of the upper articulated arm 8 by means of a cable pull 25. The cable pull 25 is guided over two deflection rollers 26, 27, which are mounted rotatably on the foot 4. Of these two deflection rollers the deflection roller 26 is provided above the tension spring 17; and the deflection roller 27 is provided below the short lever arm 8b, which belongs to the upper articulated lever 8 and is chamfered on its end at 28.

Identical components of the table are marked with the same reference numerals as in Figures 1 to 5, so that there is no need to repeat the explanation for these components at this point - a situation that also applies to the method, by which the height of the table top 1 is adjusted.

When the height of the table top 1 is adjusted, as follows from a comparison of the Figures 6 and 8, the end of the short lever arm 8b of the upper articulated lever 8 moves on an arc of a circle, whose center lies on the articulated axis at 10. The result is that the effective length of the lever arm, at which the cable pull 25 attacks, changes automatically, according to the projection. In particular, starting from the position, according to Figure 8, this effective lever arm grows larger, the further the upper articulated arm 8 is conveyed into the horizontal position, shown in Figure 6.

In this way an automatic counterbalancing of the spring force, exerted by the tension spring and which increases with the spring excursion as a consequence of the spring characteristic, is achieved, with the result that the counterbalancing of the weight of the table top 1 is in essence independent of the respectively set height level.

In the depicted embodiments the foot frame 3 exhibits two feet 4, which are arranged side by side and which are connected together by means of the transverse rail 6. Small tables could also make do with one foot 4 - which is constructed so as to match the width - and one parallelogram lever mechanism 7. Whereas the table top 1 is fastened in the manner, shown in Figure 1, to the front free end of the L-shaped carrier, said end being situated above the feet 4, it is also possible to conceive of embodiments that provide a different attachment of the table top. In these cases each of the carriers 2 can be formed - for example, as indicated in Figure 2, - by a simple vertical rail.