Height-adjustable table

Abstract: The invention relates to a height-adjustable table comprising at least two legs of adjustable length, each comprising: two leg portions telescopically slidable relative to one another and fixable in a chosen position, the lower of which may optionally support via a foot on the ground and the upper of which is coupled to a table top with coupling means, and drive means for sliding the leg portions relative to one another and coupling means for joint sliding of the leg portions of all legs such that these always have the same length, which drive means comprise: an operating mechanism such as a hand-operable crank or motor, and a screw spindle and nut co-acting therewith, of which the one is connected fixedly to the one portion of a leg and the other is connected rotatably and axially locked to the other portion of this leg and which can be set into rotation by the operating mechanism. In order to enable a very reliable height adjustment acting with little friction using very simple mechanical means, the embodiment is recommended which is characterized by a right angle transmission gear added to each leg and forming part of the drive means.

Description: The invention relates to a height-adjustable table comprising at least two legs of adjustable length, each comprising: two leg portions telescopically slidable relative to one another and fixable in a chosen position, the lower of which may optionally support via a foot on the ground and the upper of which is coupled to a table top with coupling means, and drive means for sliding the leg portions relative to one another and coupling means for joint sliding of said leg portions of all legs such that these always have the same length, which drive means comprise: an operating mechanism such as a hand-operable crank or motor, a screw spindle and a nut co-acting therewith, of which the one is connected fixedly to the one portion of a leg and the other is connected rotatably and axially locked to the other portion of this leg and which can be set into rotation by said operating mechanism, each screw spindle being connected with a right angle transmission gear accommodated in the related leg and provided with a first non-round connecting member accessible from outside the leg; and a torsion-stiff coupling rod extending between the or each pair of facing connecting members and connected therewith through a second non-round connecting member at the end of said rod and having a shape complementary to said first connecting member, at least one of said pairs of cooperating connecting members of a coupling rod comprising a non-round hole in a sleeve, in which a pressure spring is arranged for clearance-free receiving of the complementary other connecting member. Such a table is known from EP-A-0 129 941. The structure according to this prior reference requires an additional external cover in order to prevent users from contacting the driving structure that is used for the simultaneous height-adjustment of the legs. Said cover requires a substantial amount of space and furthermore does not provide a substantially dust-tight enclosure. In view of the above the table according to the invention is characterized by the features of the characterizing portion of claim 1. In order to make possible a very rapid and reliable assembly and easy dismantling of a table, the table can display in a preferred embodiment the special feature that the or each leg is coupled to the table top by means of a screw-nut connection having at least one axially running interruption embodied such that the screw and the nut can pass over one another freely therethrough in axial direction and can be coupled and tightened through rotation. Using such a connection, which is more or less akin to a known closure of for instance a jam jar, during the fitting of a leg, after reaching an axial position in which resistance can be felt, coupling of nut and screw can be carried out by rotation through a comparatively small angle and the connection can be tightened firmly, and in principle permanently, by continued turning. As stated above the height adjustment is of essential importance for ergonomic reasons, particularly in situations where very high requirements of working comfort are demanded. A user taking a seat at a table according to the invention must in a short time preferably be able first to effect a roughly correct adjustment. A table suitable therefor is preferably characterized to this end by measuring means for measuring the height of the table top and display means for visual display thereof. It should then be possible to provide the telescopically slidable portions of a leg with a scale graduation. This will not however be a very attractive solution in practice because a user must then assume unnatural positions in order to read the relevant scale. An embodiment is therefore recommended that is characterized by a pointer co-acting with a dial which is connected via transmission means to the portions of a leg. In this respect a table is recommended of which the display means are standardized in terms of the relation between body length and the average optimal table top height related thereto. A user can in this way adjust the table top to the average optimal height in a very short time. During use the user can carry out small corrections in order to adjust the table to the specific, individual, optimal working height. The invention will now be elucidated with reference to a drawing, in which: Fig. 1 shows a perspective view of a table according to the invention; fig. 2 is a cross section along II-II in fig. 1; fig. 3 is an exploded view of the top part of a leg with drive means and coupling to the table top; fig. 4 shows an operating crank and height pointer in cross section; fig. 5 shows a dial with pointer; fig. 6 is a partially broken away, perspective view of a detail wherein an alternative height measuring is shown; fig. 7 is a cross section of another embodiment of the height measurement; and fig. 8 shows the dial with pointer associated with fig. 7. figs. 9 and 10 show in detail the partition and the spring-loaded pin of the table of fig. 1 Fig. 1 shows a table 1 with four legs 2 which are of the height-adjustable type according to the invention. These legs rest by means of feet 3, 4 on the ground. Using a hand operated crank 5 the leg 2 furthest to the right can be height adjusted via an operating rod 6 in a manner to be described hereinafter. By means of torsion-free coupling rods 7, 8, 9 the length of the other three legs can also be adjusted. A measuring means 10 is connected in the manner shown in fig. 4 to the crank 5 for displaying to the user the height of the table top 11. Each of the legs 2 comprises two leg portions telescopically slidable relative to one another and fixable in a chosen position, namely a lower leg portion 12 and an upper leg portion 13. The upper leg portion 13 is connected to the table top 11 by means of coupling means to be described hereinafter. Fig. 2 shows the manner in which the upper leg portion 13 is connected to the table top 11. A transmission unit 14 is arranged fixedly at the top end of the upper leg portion 13. Via a hole 15 in this leg portion 13 a drive sleeve 16 (see also fig. 3) of square inner shape is accessible for coupling to the coupling end 17 of a coupling rod 18. Fixedly connected to the sleeve 16, which is provided internally with a pressure spring 19, is a bevel gear wheel 20 that co-acts with a second bevel gear wheel 21 rotatable about a vertical centre line, which wheel in turn is connected to a screw spindle 22. Co-acting with this screw spindle 22 is a nut unit 23 which is connected to the lower leg portion 12. By rotating the screw spindle 22, set into drive via for instance the coupling rod 18, the mutual axial position of the leg portions 12 and 13 can, as will now be apparent, be adjusted as required, while at the same time the height of the table top 11 can be adjusted. The transmission unit 14 co-acts with the table top via a hole 24 therein and supports the top 11 by means of a flange 25. An internal screw thread 26 can co-act with a corresponding screw bolt 27 with screw thread 28. Because the screw threads 26 and 28 are interrupted locally they can, through correct positioning, freely pass over axially and subsequently, as a result of a limited rotation, be coupled to one another and be tightened by exertion of a sufficiently large moment. The head 29 of the screw bolt 27 can support on an internal flange 30 in the hole 24 such that its upper face lies in the same plane as the upper face of the table top 11. Attention is drawn to the fact that the right angle transmission by means of the gear wheels 20 and 21 ensures a driving with little friction, while in the absence of driving the vertical position of the table top is nevertheless well assured because the pitch of the screw thread of the spindle 22 is small such that no relative rotation of the screw spindle 22 with respect to the nut unit 23 need be feared as a result of axial pressing. Fig. 4 shows the height adjusting crank 5. This connected for driving via the coupling rod 18 to the transmission unit 14 shown in fig. 2. Via a right angle transmission consisting of two bevel gear wheels 31, 32 and a planetary system 33 the spindle 18 also drives a pointer 34, with a large reduction. As shown in fig. 5 this pointer 34 co-acts with a dial 35 which is standardized in terms of the relation between the body length and average optimal table top height related thereto. Fig. 6 shows another manner of indicating the adjusted height. In this embodiment use is made of a drive rope 36 which is connected at one end to the fixed lower leg portion 12, this via a pin 37 which is connected to the foot 3 and enclosed telescopically overlapping by a tubular part 38 attached to the movable upper leg portion 13. This rope 36 is connected at its other end to a measuring plate 40 spring-loaded by a spiral spring 39 fixedly connected to a spindle 41 which carries the pointer 34 that co-acts with the dial 35 (see also fig. 5). By varying the height of the table top, as is described with reference to fig. 2, the pin 37 and the tubular part 38 move relative to one another, whereby the biased rope 36 causes a change in the angular position of the measuring plate 40, with a corresponding displacement of the pointer 34. Fig. 7 shows another embodiment of the measuring means. The coupling rod 18 drives a threaded rod 45 via two gear wheels 43, 44. Co-acting with the threaded rod 45 is a nut 46 locked against rotation and bearing a pointer 47. As shown in fig. 8 the point of the pointer 47 co-acts with a dial 48. Fig. 9 shows the construction of the partitions 49 shown in fig. 1. These each consist of a profiled plate 50 and a profiled plate 51 co-operating therewith. The plate 50 serving as outer partition part is connected to the upper leg portions 13 by means of spring-loaded pins 52, as indicated in fig. 10. The upper zone of the plate 50 comprises a top edge 53 twice bent over at right angles. The bottom edge 54 has a rounded form. The plate 51 which serves as inner partition part has roughly the same shape as the plate 50. The bottom edge portion 55 can, as indicated with arrow 56, be placed on and arranged in the corresponding bottom edge portion 54 of the plate 50. The top edge 57 can be placed against the top edge 53 of the plate 50 and be clamped fixedly against it by means of clamping lips 58. As will be apparent from fig. 9, the plates 50 and 51 have a shape such that at the top a comparatively large space is available, for example for accommodating wall sockets 59. The narrower space located underneath is suitable for receiving cables and the like.

Claims: Height-adjustable table (1) comprising at least two legs (2) of adjustable length, each comprising: two leg portions (12, 13) telescopically slidable relative to one another and fixable in a chosen position, the lower (12) of which may optionally support via a foot (3, 4) on the ground and the upper (13) of which is coupled to a table top (11) with coupling means (25-28), and drive means (22, 23) for sliding the leg portions (12, 13) relative to one another and coupling means (15-21) for joint sliding of said leg portions (12, 13) of all legs (2) such that these always have the same length, which drive means (22, 23) comprise: an operating mechanism (5, 6, 10) such as a hand-operable crank or motor, a screw spindle (22) and a nut (23) co-acting therewith, of which the one is connected fixedly to the one portion (12) of a leg (2) and the other is connected rotatably and axially locked to the other portion (13) of this leg (2) and which can be set into rotation by said operating mechanism (5, 6, 10,) each screw spindle (22) being connected with a right angle transmission gear (20, 21) accommodated in the related leg (2) and provided with a first non-round connecting member (16) accessible from outside the leg (2); and a torsion-stiff coupling rod (7, 8, 9) extending between the or each pair of facing connecting members (16) and connected therewith through a second non-round connecting member (17) at the end of said rod (7, 8, 9) and having a shape complementary to said first connecting member (16), at least one of said pairs of cooperating connecting members (16, 17) of a coupling rod (7, 8, 9) comprising a non-round hole in a sleeve (16), a pressure spring (19) acting between said connecting members (16, 17); characterized in that the first connecting member (16) is a sleeve entirely accommodated in the related leg (2) and is accessible for the second connecting member (17) through a hole (15) in the wall of said leg (2), the pressure spring being arranged in said sleeve (16). Table as claimed in claim 1, characterized in that the or each leg is coupled to the table top by means of a screw-nut connection having at least one axially running interruption embodied such that the screw and the nut can pass over one another freely therethrough in axial direction and can be coupled and tightened through rotation. Table as claimed in any of the preceding claims, characterized by measuring means for measuring the height of the table top and display means for visual display thereof. Table as claimed in claim 3, characterized by a pointer co-acting with a dial and connected via transmission means to the portions of a leg. Table as claimed in claims 3 and 4, characterized in that the display means are standardized in terms of the relation between body length and the average optimal table top height related thereto.

Inventors: VAN ENGELAND WIL, VAN ENGELAND, WIL
Applicants: ENGELAND MANAGEMENT BV VAN, VAN ENGELAND MANAGEMENT B.V.
Application year: 1990
Main classification: A47B9
IPC codes: A47B9, A47B17